Corrective Action Plan for Corrective Action Unit 407: Roller Coaster RADSAFE Area, Tonopah Test Range, Nevada

Energy Technology Data Exchange (ETDEWEB)

T. M. Fitzmaurice

2000-05-01

This Corrective Action Plan (CAP) has been prepared for the Roller Coaster RADSAFE Area Corrective Action Unit 407 in accordance with the Federal Facility and Consent Order (Nevada Division of Environmental Protection [NDEP] et al., 1996). This CAP provides the methodology for implementing the approved Corrective Action Alternative as listed in the Corrective Action Decision Document (U.S. Department of Energy, Nevada Operations Office, 1999). The RCRSA was used during May and June of 1963 to decontaminate vehicles, equipment, and personnel from the Clean Slate tests. The Constituents of Concern (COCs) identified during the site characterization include plutonium, uranium, and americium. No other COCS were identified. The following closure actions will be implemented under this plan: (1) Remove and dispose of surface soils which are over three times background for the area. Soils identified for removal will be disposed of at an approved disposal facility. Excavated areas will be backfilled with clean borrow soil fi-om a nearby location. (2) An engineered cover will be constructed over the waste disposal pit area where subsurface COCS will remain. (3) Upon completion of the closure and approval of the Closure Report by NDEP, administrative controls, use restrictions, and site postings will be used to prevent intrusive activities at the site. Barbed wire fencing will be installed along the perimeter of this unit. Post closure monitoring will consist of site inspections to determine the condition of the engineered cover. Any identified maintenance and repair requirements will be remedied within 90 working days of discovery and documented in writing at the time of repair. Results of all inspections/repairs for a given year will be addressed in a single report submitted annually to the NDEP.

The emperor's new mind concerning computers, minds and the laws of physics

CERN Document Server

Penrose, Roger

1989-01-01

For many decades, the proponents of `artificial intelligence' have maintained that computers will soon be able to do everything that a human can do. In his bestselling work of popular science, Sir Roger Penrose takes us on a fascinating roller-coaster ride through the basic principles of physics, cosmology, mathematics, and philosophy to show that human thinking can never be emulated by a machine.

Corrective action investigation plan for the Roller Coaster RADSAFE Area, Corrective Action Unit 407, Tonopah Test Range, Nevada

International Nuclear Information System (INIS)

1998-04-01

This Corrective Action Investigation Plan (CAIP) has been developed in accordance with the Federal Facility Agreement and Consent Order (FFACO) that was agreed to by the US Department of Energy, Nevada Operations Office (DOE/NV); the State of Nevada Division of Environmental Protection (NDEP); and the US Department of Defense (FFACO, 1996). The CAIP is a document that provides or references all of the specific information for investigation activities associated with Corrective Action Units (CAUs) or Corrective Action Sites (CASs). According to the FFACO (1996), CASs are sites potentially requiring corrective action(s) and may include solid waste management units or individual disposal or release sites. CAUs consist of one or more CASs grouped together based on geography, technical similarity, or agency responsibility for the purpose of determining corrective actions. This CAIP contains the environmental sample collection objectives and the criteria for conducting site investigation activities at CAU No. 407, the Roller Coaster RADSAFE Area (RCRSA) which is located on the Tonopah Test Range (TTR). The TTR, included in the Nellis Air Force Range Complex, is approximately 255 km (140 mi) northwest of Las Vegas, Nevada. CAU No. 407 is comprised of only one CAS (TA-23-001-TARC). The RCRSA was used during May and June 1963 to decontaminate vehicles, equipment, and personnel from the Clean Slate tests. The surface and subsurface soils are likely to have been impacted by plutonium and other contaminants of potential concern (COPCs) associated with decontamination activities at this site. The purpose of the corrective action investigation described in this CAIP is to: identify the presence and nature of COPCs; determine the vertical and lateral extent of COPCs; and provide sufficient information and data to develop and evaluate appropriate corrective actions for the CAS

Addendum to the Closure Report for Corrective Action Unit 404: Roller Coaster Sewage Lagoons and North Disposal Trench, Tonopah Test Range, Nevada, Revision 1

Energy Technology Data Exchange (ETDEWEB)

Lynn Kidman

2009-02-01

This document constitutes an addendum to the September 1998, Closure Report for Corrective Action Unit 404: Roller Coaster Lagoons and Trench, Tonopah Test Range, Nevada as described in the document Recommendations and Justifications for Modifications for Use Restrictions Established under the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office Federal Facility Agreement and Consent Order (UR Modification document) dated February 2008. The UR Modification document was approved by NDEP on February 26, 2008. The approval of the UR Modification document constituted approval of each of the recommended UR modifications. In conformance with the UR Modification document, this addendum consists of: • This cover page that refers the reader to the UR Modification document for additional information • The cover and signature pages of the UR Modification document • The NDEP approval letter • The corresponding section of the UR Modification document This addendum provides the documentation justifying the modification of the UR for CAS TA-03-001-TARC Roller Coaster Lagoons. This UR was established as part of Federal Facility Agreement and Consent Order (FFACO) corrective actions and was based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996; as amended August 2006). Since this UR was established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, this UR was re-evaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006c). This reevaluation consisted of comparing the original data (used to define the need for the UR) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to modify the UR for CAS TA-03

CSIR ScienceScope: Future of our science

CSIR Research Space (South Africa)

CSIR

2007-06-01

Full Text Available antimonite (InAsSb), as it is more Science-driven bursar shifts boundaries in pursuit of dreams Dreams do come true. Some are easy to achieve, while others require one to go that extra mile to realise them. When her parents’ financial constraints nearly... halted her dreams to study, Tshepiso Mothibinyane decided to go the distance in pursuit of her goals. “It’s been a roller-coaster ride, but I have enjoyed every moment of it thoroughly!” stable, uniform and has a cut-off wave- length that can...

PENGUKURAN TINGKAT KEBISINGAN PADA KAPAL COASTER

Directory of Open Access Journals (Sweden)

Eko Julianto Sasono

2012-03-01

Full Text Available The noise on the ship is a fitness factor. When it is over, can effect the healthy and concentration of crews, finally it can effect safety of ships. The rules of noise level for commercial ship is inserted in ”Code on noise levels on board ships” of IMO. The noise level evaluate of Coaster ship have done when the main machine speed is 85 % MCR. The evaluate used Noise Onsoku of equipment. The navigation when it was evaluated was sea trial. As a result, the noise level of Coaster ship is still get the specification of IMO codes.

A brief history of light and those that lit the way

CERN Document Server

Weiss, Richard J

1996-01-01

From Leonardo to Oppenheimer, from candles to lasers, from cave drawings to cinema, from Stonehenge to quantum mechanics, from Genesis to the Big Bang, light has filled our thoughts, our way of life, our aesthetics, our technology, and our means for survival. Richard Weiss leads us along these paths over the past 500 light years. The way is lit by pioneers such as Rembrandt, Einstein, D W Griffith, Newton, and Heisenberg. A Brief History Of Light, And Those That Lit The Way is a summer's day roller-coaster ride through five centuries of man's achievements in understanding and manipulati

Emotional roller-coaster

Energy Technology Data Exchange (ETDEWEB)

Bathke, Rouben; Grunwald, Markus

2011-07-01

While the dominating theme during Energethica in April was the unclear future of the Italian incentive scheme, Solarexpo sent a wave of relief through the ranks at the beginning of May when the Italian government announced the new feed-in tariff rates on the second day. (orig.)

Rock 'n Roller Coaster

DEFF Research Database (Denmark)

Timmermans, Bram; Bekkers, Rudi; Bordoli, Luca

Over the past decades, empirical evidence has been collected on the evolution of industries. Most of these studies follow the traditional three-stage model inspired by Utterback and Abernathy’s (1975) product life cycle. These stages are: (i) the initial growth stage during which the number...... the knowledge is considered the main driving force of the life cycle pattern (Cantner et al. 2009). In addition, this knowledge diffusion and the ability of the industry to absorb the knowledge of exiting firms can be regarded as an important indicator of the resilience of this industry. This paper applies...

Roller bearing geometry design

Science.gov (United States)

Savage, M.; Pinkston, B. H. W.

1976-01-01

A theory of kinematic stabilization of rolling cylinders is extended and applied to the design of cylindrical roller bearings. The kinematic stabilization mechanism puts a reverse skew into the rolling elements by changing the roller taper. Twelve basic bearing modification designs are identified amd modeled. Four have single transverse convex curvature in their rollers while eight have rollers which have compound transverse curvature made up of a central cylindrical band surrounded by symmetric bands with slope and transverse curvature. The bearing designs are modeled for restoring torque per unit axial displacement, contact stress capacity, and contact area including dynamic loading, misalignment sensitivity and roller proportion. Design programs are available which size the single transverse curvature roller designs for a series of roller slopes and load separations and which design the compound roller bearings for a series of slopes and transverse radii of curvature. The compound rollers are proportioned to have equal contact stresses and minimum size. Design examples are also given.

Clean slate corrective action investigation plan

International Nuclear Information System (INIS)

1996-05-01

The Clean Slate sites discussed in this report are situated in the central portion of the Tonopah Test Range (TTR), north of the Nevada Test Site (NTS) on the northwest portion of the Nellis Air Force Range (NAFR) which is approximately 390 kilometers (km) (240 miles [mi]) northwest of Las Vegas, Nevada. These sites were the locations for three of the four Operation Roller Coaster experiments. These experiments evaluated the dispersal of plutonium in the environment from the chemical explosion of a plutonium-bearing device. Although it was not a nuclear explosion, Operation Roller Coaster created some surface contamination which is now the subject of a corrective action strategy being implemented by the Nevada Environmental Restoration Project (NV ERP) for the U.S. Department of Energy (DOE). Corrective Action Investigation (CAI) activities will be conducted at three of the Operation Roller Coaster sites. These are Clean Slate 1 (CS-1), Clean Slate 2 (CS-2), and Clean Slate 3 (CS-3) sites, which are located on the TTR. The document that provides or references all of the specific information relative to the various investigative processes is called the Corrective Action Investigation Plan (CAIP). This CAIP has been prepared for the DOE Nevada Operations Office (DOE/NV) by IT Corporation (IT)

Clean slate corrective action investigation plan

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-05-01

The Clean Slate sites discussed in this report are situated in the central portion of the Tonopah Test Range (TTR), north of the Nevada Test Site (NTS) on the northwest portion of the Nellis Air Force Range (NAFR) which is approximately 390 kilometers (km) (240 miles [mi]) northwest of Las Vegas, Nevada. These sites were the locations for three of the four Operation Roller Coaster experiments. These experiments evaluated the dispersal of plutonium in the environment from the chemical explosion of a plutonium-bearing device. Although it was not a nuclear explosion, Operation Roller Coaster created some surface contamination which is now the subject of a corrective action strategy being implemented by the Nevada Environmental Restoration Project (NV ERP) for the U.S. Department of Energy (DOE). Corrective Action Investigation (CAI) activities will be conducted at three of the Operation Roller Coaster sites. These are Clean Slate 1 (CS-1), Clean Slate 2 (CS-2), and Clean Slate 3 (CS-3) sites, which are located on the TTR. The document that provides or references all of the specific information relative to the various investigative processes is called the Corrective Action Investigation Plan (CAIP). This CAIP has been prepared for the DOE Nevada Operations Office (DOE/NV) by IT Corporation (IT).

Physics in the Real World...Teaching outside the Textbook. A Teacher's Perspective on the Principles of Technology.

Science.gov (United States)

Rosengrant, David

2003-01-01

A physics teacher in a technical high school describes how he teaches outside the book through lab involvement, student projects, and thematic lessons. Describes a roller coaster construction project. (JOW)

Kinematic correction for roller skewing

Science.gov (United States)

Savage, M.; Loewenthal, S. H.

1980-01-01

A theory of kinematic stabilization of rolling cylinders is developed for high-speed cylindrical roller bearings. This stabilization requires race and roller crowning to product changes in the rolling geometry as the roller shifts axially. These changes put a reverse skew in the rolling elements by changing the rolling taper. Twelve basic possible bearing modifications are identified in this paper. Four have single transverse convex curvature in the rollers while eight have rollers with compound transverse curvature composed of a central cylindrical band of constant radius surrounded by symmetric bands with both slope and transverse curvature.

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, For Calendar Year 2008

International Nuclear Information System (INIS)

2009-01-01

This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Unit (CAU) sites located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2008 and includes inspection and repair activities completed at the following ten CAUs: CAU 400: Bomblet Pit and Five Points Landfill (TTR) CAU 404: Roller Coaster Lagoons and Trench (TTR) CAU 407: Roller Coaster RadSafe Area (TTR) CAU 423: Area 3 Underground Discharge Point, Building 0360 (TTR) CAU 424: Area 3 Landfill Complexes (TTR) CAU 426: Cactus Spring Waste Trenches (TTR) CAU 427: Area 3 Septic Waste Systems 2, 6 (TTR) CAU 453: Area 9 UXO Landfill (TTR) CAU 484: Surface Debris, Waste Sites, and Burn Area (TTR) CAU 487: Thunderwell Site (TTR)

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, For Calendar Year 2008

Energy Technology Data Exchange (ETDEWEB)

NSTec Environmental Restoration

2009-03-19

This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Unit (CAU) sites located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2008 and includes inspection and repair activities completed at the following ten CAUs: CAU 400: Bomblet Pit and Five Points Landfill (TTR) CAU 404: Roller Coaster Lagoons and Trench (TTR) CAU 407: Roller Coaster RadSafe Area (TTR) CAU 423: Area 3 Underground Discharge Point, Building 0360 (TTR) CAU 424: Area 3 Landfill Complexes (TTR) CAU 426: Cactus Spring Waste Trenches (TTR) CAU 427: Area 3 Septic Waste Systems 2, 6 (TTR) CAU 453: Area 9 UXO Landfill (TTR) CAU 484: Surface Debris, Waste Sites, and Burn Area (TTR) CAU 487: Thunderwell Site (TTR)

Kinematics of Planetary Roller Screw Mechanism considering Helical Directions of Screw and Roller Threads

Directory of Open Access Journals (Sweden)

Shangjun Ma

2015-01-01

Full Text Available Based on the differential principle of thread transmission, an analytical model considering helical directions between screw and roller threads in planetary roller screw mechanism (PRSM is presented in this work. The model is critical for the design of PRSM with a smaller lead and a bigger pitch to realize a higher transmission accuracy. The kinematic principle of planetary transmission is employed to analyze the PRSM with different screw thread and roller thread directions. In order to investigate the differences with different screw thread and roller thread directions, the numerical model is developed by using the software Adams to validate the analytical solutions calculated by the presented model. The results indicate, when the helical direction of screw thread is identical with the direction of roller thread, that the lead of PRSM is unaffected regardless of whether sliding between screw and rollers occurs or not. Only when the direction of screw thread is reverse to the direction of roller thread, the design of PRSM with a smaller lead can be realized under a bigger pitch. The presented models and numerical simulation method can be used to research the transmission accuracy of PRSM.

Lost in Translation (LiT): IUPHAR Review 6.

Science.gov (United States)

Dollery, Colin T

2014-05-01

Translational medicine is a roller coaster with occasional brilliant successes and a large majority of failures. Lost in Translation 1 ('LiT1'), beginning in the 1950s, was a golden era built upon earlier advances in experimental physiology, biochemistry and pharmacology, with a dash of serendipity, that led to the discovery of many new drugs for serious illnesses. LiT2 saw the large-scale industrialization of drug discovery using high-throughput screens and assays based on affinity for the target molecule. The links between drug development and university sciences and medicine weakened, but there were still some brilliant successes. In LiT3, the coverage of translational medicine expanded from molecular biology to drug budgets, with much greater emphasis on safety and official regulation. Compared with R&D expenditure, the number of breakthrough discoveries in LiT3 was disappointing, but monoclonal antibodies for immunity and inflammation brought in a new golden era and kinase inhibitors such as imatinib were breakthroughs in cancer. The pharmaceutical industry is trying to revive the LiT1 approach by using phenotypic assays and closer links with academia. LiT4 faces a data explosion generated by the genome project, GWAS, ENCODE and the 'omics' that is in danger of leaving LiT4 in a computerized cloud. Industrial laboratories are filled with masses of automated machinery while the scientists sit in a separate room viewing the results on their computers. Big Data will need Big Thinking in LiT4 but with so many unmet medical needs and so many new opportunities being revealed there are high hopes that the roller coaster will ride high again. © 2014 The British Pharmacological Society.

Self-Mobilization Using a Foam Roller Versus a Roller Massager: Which Is More Effective for Increasing Hamstrings Flexibility?

Science.gov (United States)

DeBruyne, Danielle M; Dewhurst, Marina M; Fischer, Katelyn M; Wojtanowski, Michael S; Durall, Chris

2017-01-01

Clinical Scenario: Increasing the length of the muscle-tendon unit may prevent musculotendinous injury. Various methods have been proposed to increase muscle-tendon flexibility, including self-mobilization using foam rollers or roller massagers, although the effectiveness of these devices is uncertain. This review was conducted to determine if the use of foam rollers or roller massagers to improve hamstrings flexibility is supported by moderate- to high-quality evidence. Are foam rollers or roller massagers effective for increasing hamstrings flexibility in asymptomatic physically active adults? Summary of Key Findings: The literature was searched for studies on the effects of using foam rollers or roller massagers to increase hamstrings flexibility in asymptomatic physically active adults. Four randomized controlled trials were included; 2 studies provided level 2 or 3 evidence regarding foam rollers and 2 studies provided level 2 or 3 evidence regarding roller massagers. Both roller-massager studies reported increases in hamstrings flexibility after treatment. Data from the foam-roller studies did not demonstrate a statistically significant increase in hamstrings flexibility, but 1 study did demonstrate a strong effect size. Clinical Bottom Line: The reviewed moderate-quality studies support the use of roller massagers but provide limited evidence on the effectiveness of foam rolling to increase hamstrings flexibility in asymptomatic physically active adults. Flexibility gains may be improved by a longer duration of treatment and administration by a trained therapist. Gains appear to decline rapidly postrolling. Neither device has been shown to confer a therapeutic benefit superior to static stretching, and the effectiveness of these devices for preventing injury is unknown. Strength of Recommendation: Grade B evidence supports the use of roller massagers to increase hamstrings flexibility in asymptomatic physically active adults.

The Trajectory of Chronic Pain: Can a Community-Based Exercise/Education Program Soften the Ride?

Directory of Open Access Journals (Sweden)

Ruth Dubin

2010-01-01

Full Text Available The entire primary care record of six patients attending a community-based education/exercise self-management program for chronic noncancer pain (YMCA Pain Exercise/Education Program [Y-PEP] was reviewed. Medical visits, consultations and hospital admissions were coded as related or unrelated to their pain diagnoses. Mood disruption, financial concerns, conflicts with employers/insurers, analgesic doses, medication side effects and major life events were also recorded. The ‘chronic pain trajectory’ resembled a roller coaster with increased health care visits at the time of initial injuries and during ‘crises’ (reinjury, conflict with insurers/employers, failed back-to-work attempts and life events. Visits decreased when conflicts were resolved. Analgesic doses increased during ‘crises’ but did not fall after resolution. After attending Y-PEP, health care use fell for four of six patients and two returned to work. Primary care physicians need to recognize the functional limitations and psychosocial complications experienced by their chronic pain patients. A program such as Y-PEP may promote active self-management strategies resulting in lowered health care use.

Problematics of Reliability of Road Rollers

Science.gov (United States)

Stawowiak, Michał; Kuczaj, Mariusz

2018-06-01

This article refers to the reliability of road rollers used in a selected roadworks company. Information on the method of road rollers service and how the service affects the reliability of these rollers is presented. Attention was paid to the process of the implemented maintenance plan with regard to the machine's operational time. The reliability of road rollers was analyzed by determining and interpreting readiness coefficients.

PrivateRide: A Privacy-Enhanced Ride-Hailing Service

Directory of Open Access Journals (Sweden)

Pham Anh

2017-04-01

Full Text Available In the past few years, we have witnessed a rise in the popularity of ride-hailing services (RHSs, an online marketplace that enables accredited drivers to use their own cars to drive ride-hailing users. Unlike other transportation services, RHSs raise significant privacy concerns, as providers are able to track the precise mobility patterns of millions of riders worldwide. We present the first survey and analysis of the privacy threats in RHSs. Our analysis exposes high-risk privacy threats that do not occur in conventional taxi services. Therefore, we propose PrivateRide, a privacy-enhancing and practical solution that offers anonymity and location privacy for riders, and protects drivers’ information from harvesting attacks. PrivateRide lowers the high-risk privacy threats in RHSs to a level that is at least as low as that of many taxi services. Using real data-sets from Uber and taxi rides, we show that PrivateRide significantly enhances riders’ privacy, while preserving tangible accuracy in ride matching and fare calculation, with only negligible effects on convenience. Moreover, by using our Android implementation for experimental evaluations, we show that PrivateRide’s overhead during ride setup is negligible. In short, we enable privacy-conscious riders to achieve levels of privacy that are not possible in current RHSs and even in some conventional taxi services, thereby offering a potential business differentiator.

The troubled HMO industry: what's next?

Science.gov (United States)

Cerone, J R

1988-01-01

The fortunes of health maintenance organizations (HMOs) have been on a roller coaster ride for the last 15 years. Growth rates in the number and total enrollments of HMOs surged in 1973 and 1974 following passage of the federal HMO Act. Growth rates abated over the next 8 years. Several favorable factors converged in 1983 to push growth rates back up. Some 15 for-profit HMO companies went public with initial stock offerings during the 1983-85 period. Their stock prices soared as they compiled astounding records of enrollment, revenue and profit growth. In the next 2 years, however, stock prices dropped as quickly as they had risen. Intense price competition and inexperienced managers were important factors contributing to sharp descents in HMO earnings in 1986 and 1987. Some analysts now see positive signs pointing to an industry recovery. However, investors are not convinced of this as HMO stock prices remain severely depressed.

Roller-compacted concrete pavements.

Science.gov (United States)

2010-09-01

Roller-compacted concrete (RCC) gets its name from the heavy vibratory steel drum and rubber-tired rollers used to help compact it into its final form. RCC has similar strength properties and consists of the same basic ingredients as conventional con...

Development of roller type side slip tester; Roller shiki side slip tester no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Nishiyama, S [Hiroshima City Industrial Technology Institute, Hiroshima (Japan); Harada, S; Harada, K

1997-10-01

This paper presents a new development of roller type side slip tester (RTSSI). The test equipment consists of four parts, which are developed in this research. These are a roller part, a control part, a remote control part and a CRT part. In this study, we especially investigated the mechanism and performance between tire and roller. We analyzed the amount of side slip with various toe angles. The developed tester is examined under the conditions that is considered in industrial applications. We investigated the influences of toe angle, size of tire, pressure of tire, coefficient of friction between tire and roller, pushing force of tire, revolution velocity of roller, axle load and so on. The validity of the developed RTSST is confirmed under these conditions. It was found that the RTSST can be used in practical use. Some measurement results are presented in the form of parametric plots. And we also compared measurements data between the RTSST and that of flat type using several automobiles. 4 refs., 8 figs., 4 tabs.

Analisa Beban Kerja Dan Gaya Dinamis Pada Round Roller Dan Sliding Roller Untuk Sistem CVT (Continuously Variable Transmission Sepeda Motor Matic

Directory of Open Access Journals (Sweden)

Ahmad Bagus Prasojo

2017-01-01

Full Text Available Primary shave weight atau sering disebut roller merupakan salah satu komponen dari sistem CVT pada motor matik yang sering mengalami kerusakan, baik itu aus maupun crack atau pecah. Metodologi yang dilakukan pada penelitian ini adalah menganalisa beban kerja (gaya yang dialami oleh roller. Selanjutnya akan dihitung besar tegangan (stress yang terjadi pada roller menggunakan teori tegangan kontak (contact stress. Kemudian analisa akan dilanjutkan menggunakan teori kelelahan (fatigue. Gaya normal yang didapat pada posisi stasioner sebesar 37,268 N dan posisi puncak sebesar 525,279 N. Untuk total tegangan ekivalen yang terjadi berbeda dikarenakan luasan kontaknya, round roller dengan luasan kontak yang lebih kecil menghasilkan total tegangan yang lebih besar yaitu 21,423 MPa sedangkan sliding roller sebesar 14,559 MPa. Dengan frekuensi real pembebanan roller sebesar 0,0667 Hz dan berdasarkan teori kelelahan Gerber stress amplitude round roller didapatkan 8,8756 Mpa dan untuk sliding roller sebesar 6,195 Mpa. Jadi setelah stress amplitude diplotkan pada sn-curve PTFE hasil prediksi umur untuk round roller adalah 4,081 ≈ 4 bulan dan untuk sliding roller adalah 5,89 ≈ 6 bulan.

Saying 'Yes' and 'No' in Matters of Personal Taste

NARCIS (Netherlands)

Buekens, Filip

This paper examines the communicative function of public pronouncements about what is tasty, agreeable or attractive, followed by an equally public endorsement or rejection. The typical and expected reaction to contributions like 'This is tasty' or 'The roller coaster is fun' in a conversational

The 1982 epidemic--roller skating injuries.

Science.gov (United States)

Bunker, T. D.

1983-01-01

A series of 100 roller skating injuries is presented. Roller skating injuries have been occurring at a higher rate than the previously reported skateboarding epidemic of 1977. The severity of injury has been lower, 32% fractures and dislocations occurring whilst roller skating, compared to 60% whilst skateboarding. In particular a striking reduction is seen in ankle fractures. Fifty questionnaires detailing method of injury were analysed. Images p205-a Fig. 1 Fig. 2 PMID:6652406

Development of ceramic roller bush for diesel fuel injection pump; Nenryo funsha pump yo ceramics sei roller bush no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Noda, K; Kamiya, S; Fujimura, M; Tsuzuki, M [Toyota Motor Corp., Aichi (Japan); Taniguchi, K [Denso Corp., Aichi (Japan)

1997-10-01

Silicon nitride ceramics have been applied to roller bush for diesel fuel injection pump in order to improve the seizure resistance. It was found that ceramic roller bush made it possible to improve the seizure load by more than three times as compared to conventional metal roller bush when the kerosene was used as lubricant The ceramic roller bush proved to be durable under engine operating conditions. 6 refs., 13 figs., 1 tab.

49 CFR 215.115 - Defective roller bearing.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Defective roller bearing. 215.115 Section 215.115... § 215.115 Defective roller bearing. (a) A railroad may not place or continue in service a car, if the car has— (1) A roller bearing that shows signs of having been overheated as evidenced by— (i...

Depreciation of bearing blocks of rollers of roller conveyers of rolling mills

Science.gov (United States)

Artiukh, Viktor; Belyaev, Michael; Ignatovich, Igor; Miloradova, Nadezda

2017-10-01

Essential increase in functional durability of a node of a roller of the roller conveyer of the rolling mill by the rational choice of parameters of the small-size shock-absorber (buffer adapter) is shown. At the same time dimensions of a node don’t change, costs of reconstruction are small. The possibility of management of loadings in a bearing node without change of technology parameters of the process which is carried out by the rolling mill is confirmed.

The unsilencing of military wives: wartime deployment experiences and citizen responsibility.

Science.gov (United States)

Davis, Jennifer; Ward, David B; Storm, Cheryl

2011-01-01

One of therapists' contemporary moral imperatives is to support American service members and their families regardless of personal position on the Global War on Terrorism. One way therapists can respond to this imperative is by seeking to understand Army wives' experiences during their husbands' wartime deployments. Therefore, this study utilized a combination of individual interviews with Army wives and a reflecting team of military wives and civilians to explore military wives' experiences. Two main themes were identified: the wives' experience was an emotional roller coaster and they felt silenced--and could be unsilenced--in their interactions with civilians. Therapists working with Army wives should (a) normalize the roller-coaster experience; (b) encourage wives to recognize negative and positive influencers and explore their idiosyncratic coping skills; (c) support positive civilian-military connections; and (d) as a civilian and as a therapist, seek to be a positive civilian connection by proactively showing support. © 2011 American Association for Marriage and Family Therapy.

ROLLER RIG TESTING AT THE CZECH TECHNICAL UNIVERSITY

Directory of Open Access Journals (Sweden)

J. Kalivoda

2016-08-01

Full Text Available Purpose. Although the advancements in computer simulation technology have paved way to provide very reliable simulation results, track tests still play an essential role during the process of development and homologation of any railway vehicle. On the other hand, track tests depend on weather conditions, are difficult to organize and are not suitable for testing vehicles in critical situations. On a roller rig, the tested vehicle is longitudinally fixed and a track is replaced by rotating rollers. Such device offer testing of railway vehicle running dynamics in safe and stable laboratory environment. The purpose of an article is to investigate and describe roller rig testing at the Czech technical university in Prague (CTU. Methodology. In the paper it is shown the history of development of the scaled CTU roller rig from the earlier stages until the current projects for which the CTU roller rig is utilized for. The current design of the experimental bogie, roller rig, sensors instrumentation and types of experiments conducted at the CTU roller rig are described in more detail. Findings. Although the differences in vehicle behaviour on a track and a scaled model on a roller rig are not negligible, scaled roller rig experiments are found as a relatively inexpensive way for verification and demonstration of computer simulations results. They are especially useful for verification of multibody system simulations (MBS of entirely new running gear concepts. Originality. The CTU roller rig is currently used for the experiments with active controlled wheelset guidance. According to simulations results published in many papers such systems offer, in principle, better performance compared to conventional passive vehicles. However, utilization and testing of active controlled wheelset guidance on vehicles is still rare. CTU roller rig serves as a tool to verify computer simulations and demonstrate benefits of active wheelset guidance. Practical value

Society Membership Profile: Employment Mobility and Career Change. AIP Report.

Science.gov (United States)

Porter, Beverly Fearn; Kellman, Dawn

Information on the influence of employment mobility and career change on the flexibility of the physics labor force is provided, noting the past several decades have brought a dramatic roller coaster of changes to the physics community. Five sections are as follows: membership composition (demographics, professional self-identification, and…

Proceedings of the opportunities in the synfuels industry

Energy Technology Data Exchange (ETDEWEB)

1992-12-31

World interest in coal-based synthetic fuels technology is like a roller coaster ride. Interest soars when energy prices are high or world oil supplies are threatened. When energy is inexpensive and oil is plentiful, interest plummets. However, some people remain undaunted by the ups and downs of the synfuels industry. They cling tenaciously to the idea that coal-based synthetic fuels are the world`s energy future. They are the select group attending the SynOps `92 symposium in Bismarck, North Dakota. SynOps `92 participants represent an extraordinary combination of visionaries and practical thinkers. They believe the ``coal refinery`` concept will eventually provide the most efficient and productive use of our coal resources. They know that coal is a valuable resource which can be used to produce a huge variety of valuable nonfuel products. They also recognize that until technology can make alternative fuels economically feasible, the world will continue to rely heavily on fossil fuels--especially coal, the world`s most abundant energy resource. Individual papers have been entered.

Science behind the scenes during Fossett's recent around-the-world ballooning effort

Science.gov (United States)

Showstack, Randy

“In my mind, there's no question. If you eliminate that one temporary setback, he completes the global,” Bob Rice said on August 17, exhausted after having slept little during the previous 8 ½ days of intensive weather forecasting and emotional roller coaster riding.As chief meteorologist for the Solo Spirit balloon trip, Rice helped to navigate 54-yearold balloonist and businessman Steve Fossett on his fourth attempt to circle the globe nonstop. During that effort, which began at 23:30 UTC on August 7 from Mendoza, Argentina, Fossett had floated 24,460 km—63% of the way around the world longitudinally-surpassing his previous world distance record of 16,674 km set in January 1997. His “roziere” balloon, a combination of gas and hot air, had risen or descended to avoid violent weather systems and winds that would blow him in the wrong direction, and to catch air currents that would push his vessel along. With the Atlantic and Indian Oceans and Australia behind him, only the wide Pacific Ocean lay in Fossett's path.

Proceedings of the opportunities in the synfuels industry

International Nuclear Information System (INIS)

1992-01-01

World interest in coal-based synthetic fuels technology is like a roller coaster ride. Interest soars when energy prices are high or world oil supplies are threatened. When energy is inexpensive and oil is plentiful, interest plummets. However, some people remain undaunted by the ups and downs of the synfuels industry. They cling tenaciously to the idea that coal-based synthetic fuels are the world's energy future. They are the select group attending the SynOps '92 symposium in Bismarck, North Dakota. SynOps '92 participants represent an extraordinary combination of visionaries and practical thinkers. They believe the ''coal refinery'' concept will eventually provide the most efficient and productive use of our coal resources. They know that coal is a valuable resource which can be used to produce a huge variety of valuable nonfuel products. They also recognize that until technology can make alternative fuels economically feasible, the world will continue to rely heavily on fossil fuels--especially coal, the world's most abundant energy resource. Individual papers have been entered

Ice-skating and roller disco injuries in Dublin.

OpenAIRE

Horner, C.; McCabe, M. J.

1984-01-01

A comparative study was carried out on a series of 72 ice-skating and 57 roller skating injuries over a sixteen month period. The average patient age was 20.5 years in the ice-skating group and 16.5 years in the roller skating group. Females predominated in both groups accounting for 72% of ice-skaters injured and 77% of roller skaters injured. Ice-skaters sustained more serious injuries than roller skaters as was evident from the significant difference in fracture numbers in the two groups. ...

Ice-skating and roller disco injuries in Dublin.

Science.gov (United States)

Horner, C.; McCabe, M. J.

1984-01-01

A comparative study was carried out on a series of 72 ice-skating and 57 roller skating injuries over a sixteen month period. The average patient age was 20.5 years in the ice-skating group and 16.5 years in the roller skating group. Females predominated in both groups accounting for 72% of ice-skaters injured and 77% of roller skaters injured. Ice-skaters sustained more serious injuries than roller skaters as was evident from the significant difference in fracture numbers in the two groups. Ice-skating fractures accounted for 40% of all injuries while roller skating fractures were only 14% of their total injuries. The majority of ice-skating fractures occurred in females. As a result of our study we recommended several preventative measures. Images p207-a p207-b PMID:6487948

Snapshots: Marimba Magic; Rediscovering Coyote and Raven; New Life for an Old War; Good Health, Good Heart; Winds of Change; What the Forest Gives; Lessons in the Loop; a Talking Book.

Science.gov (United States)

Reed, Bracken; Linik, Joyce Riha; Muir, Maya; Fisher, Amy

2002-01-01

Applications of project-based learning are illustrated by examples of projects involving music, art, history, a partnership with a hospital, Native American plant remedies, roller coaster design, and making a "talking book" (CD-ROM) in English and Lushootseed (language of the Tulalip Tribes). Project learning can meet standards while involving…

21 CFR 870.4370 - Roller-type cardiopulmonary bypass blood pump.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Roller-type cardiopulmonary bypass blood pump. 870... Roller-type cardiopulmonary bypass blood pump. (a) Identification. A roller-type cardiopulmonary bypass blood pump is a device that uses a revolving roller mechanism to pump the blood through the...

49 CFR 215.117 - Defective roller bearing adapter.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Defective roller bearing adapter. 215.117 Section... Suspension System § 215.117 Defective roller bearing adapter. A railroad may not place or continue in service a car, if the car has a roller bearing adapter that is— (a) Cracked or broken; (b) Not in its design...

Engine testing of ceramic cam-roller followers

Energy Technology Data Exchange (ETDEWEB)

Kalish, Y. (Detroit Diesel Corp., MI (United States))

1992-04-01

For several years, DDC has been developing monolithic ceramic heat engine components. One of the components, developed for an application in our state-of-the-art on-highway, heavy-duty diesel engine, the Series 60, is a silicon nitride cam-roller follower. Prior to starting this program, each valve train component in the Series 60 was considered for conversion to a ceramic material. Many advantages and disadvantages (benefits and risks) were considered. From this effort, one component was selected, the cam-roller follower. Using a system design approach, a ceramic cam-roller follower offered functional improvement at a reasonable cost. The purpose of the project was to inspect and test 100 domestically produced silicon nitride cam-roller followers built to the requirements of the DDC series 60 engine.

Design algorithm for generatrix profile of cylindrical crowned rollers

Directory of Open Access Journals (Sweden)

Creţu Spiridon

2017-01-01

Full Text Available The cross-section of roller profile controls the pressure distribution in the contact area and radically affects the roller bearings basic dynamic load rating and rating lives. Today the most used roller profiles are the logarithmic profile and cylindrical-crowned (ZB profile. The logarithmic profile has a continuous evolution with no discontinuities till the intersection with the end fillet while ZB profile has two more discontinuities at the intersections points between the crowning circle and straight line generatrix. Using a semianalytical method, a numerical study has been carried out to find the optimum ZB profile for rollers incorporated in cylindrical rollers bearings. The basic reference rating life (L10_r has been used as optimization criterion.

49 CFR 230.103 - Tender roller bearing journal boxes.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Tender roller bearing journal boxes. 230.103... Locomotives and Tenders Running Gear § 230.103 Tender roller bearing journal boxes. Tender roller bearing journal boxes shall be maintained in a safe and suitable condition. ...

Safety First: Safety--The Elementary Mission

Science.gov (United States)

Roy, Ken

2013-01-01

Activities involving the construction of a model solar oven, soda bottle rocket, catapult, bridge, roller coaster, playground, and plane glider all have one thing in common. They are examples of STEM project activities for elementary students. STEM is one of the areas of emphasis in the "Next Generation Science Standards" (NGSS), which…

Numerically Analysed Thermal Condition of Hearth Rollers with the Water-Cooled Shaft

Directory of Open Access Journals (Sweden)

A. V. Ivanov

2016-01-01

Full Text Available Continuous furnaces with roller hearth have wide application in the steel industry. Typically, furnaces with roller hearth belong to the class of medium-temperature heat treatment furnaces, but can be used to heat the billets for rolling. In this case, the furnaces belong to the class of high temperature heating furnaces, and their efficiency depends significantly on the reliability of the roller hearth furnace. In the high temperature heating furnaces are used three types of watercooled shaft rollers, namely rollers without insulation, rollers with insulating screens placed between the barrel and the shaft, and rollers with bulk insulation. The definition of the operating conditions of rollers with water-cooled shaft greatly facilitates the choice of their design parameters when designing. In this regard, at the design stage of the furnace with roller hearth, it is important to have information about the temperature distribution in the body of the rollers at various operating conditions. The article presents the research results of the temperature field of the hearth rollers of metallurgical heating furnaces. Modeling of stationary heat exchange between the oven atmosphere and a surface of rollers, and between the cooling water and shaft was executed by finite elements method. Temperature fields in the water-cooled shaft rollers of various designs are explored. The water-cooled shaft rollers without isolation, rollers with screen and rollers with bulk insulation, placed between the barrel and the water-cooled shaft were investigated. Determined the change of the thermo-physic parameters of the coolant, the temperature change of water when flowing in a pipe and shaft, as well as the desired pressure to supply water with a specified flow rate. Heat transfer coefficients between the cooling water and the shaft were determined directly during the solution based on the specified boundary conditions. Found that the greatest heat losses occur in the

Kinematics and Dynamics of Roller Chain Drives

DEFF Research Database (Denmark)

Fuglede, Niels

There are two main subjects of this work: Kinematic and dynamic modeling and analysis of roller chain drives. In the kinematic analysis we contribute first with a complete treatment of the roller chain drive modeled as a four-bar mechanism. This includes a general, exact and approximate analysis...... which is useful for predicting the characteristic loading of the roller chain drive. As a completely novel contribution, a kinematic model and analysis is presented which includes both spans and sprockets in a simple chain drive system. A general procedure for determination of the total wrapping length...... is presented, which also allows for exact sprocket center positions for a chain with a given number of links. Results show that the total chain wrapping length varies periodically with the tooth frequency. These results are of practical importance to both the design, installation and operation of roller chain...

Dial-a-Ride

DEFF Research Database (Denmark)

Jørgensen, Rene Munk

2003-01-01

The Dial-a-Ride problem is a Vehicle Routing problem in its most general form. The problem was formulated in the beginning of the 1970's and since then a large number of researchers have worked on developing efficient algorithms for use in automated planning of Dial-a-Ride transportation systems....... In a Dial-a-Ride transportation system, passengers request a trip between two stops with either a desired time of departure from the pickup stop or a desired time of arrival at the destination. The time windows at the stops are then calculated by the operator based on additional parameters such as maximum...... to the problem. The metod used in this thesis is based on a clustering first insertion second technique developed at CRT in Canada in the mid 1980's. The algorithm is extended to include constraints imposed by a practical Dial-a-Ride problem at a Danish transportation operator. These constraints are mainly...

Roller-chain Drives Mechanics using Multibody Dynamics Tools

DEFF Research Database (Denmark)

Ambrosio, Jorge A. C.; Hansen, John Michael

1999-01-01

An integrated model for the simulation of roller-chain drives based on a multibody dynamics methodology is presented here in order to describeits complex dynamic behavior. The chain is modeled by masses lumped at the roller locations and connected by translational spring-damper elements in order ...... engagement on the sprockets responsible for the polygonal effect is thoroughly analyzed and the induced impulsive forces developed during that action are treated by a strategy where kinematic constraints between sprockets and rollers are added and deleted....

A FILTRATION METHOD AND APPARATUS INCLUDING A ROLLER WITH PORES

DEFF Research Database (Denmark)

2008-01-01

The present invention offers a method for separating dry matter from a medium. A separation chamber is at least partly defined by a plurality of rollers (2,7) and is capable of being pressure regulated. At least one of the rollers is a pore roller (7) having a surface with pores allowing permeabi...

In their own time: the family experience during the process of withdrawal of life-sustaining therapy.

Science.gov (United States)

Wiegand, Debra

2008-10-01

Withdrawal of life-sustaining therapy (LST) occurs commonly in critical care units, yet little is known about the family experience with this process. The purpose of this study was to understand the lived experience of families participating in the process of withdrawal of LST from a family member with an unexpected, life-threatening illness or injury. A hermeneutic phenomenological approach was used as nineteen families were interviewed and observed. Within and across family analyses were conducted. Methodological rigor was established and redundancy was achieved. The categories that evolved from the data included: this happens to other families, time to understand the severity of the illness or injury, time to see if health would be restored, riding a roller coaster, family readiness: willingness to consider withdrawal of LST as a possible option, one step at a time, family readiness: time to make a decision, the family will go on, and waiting for a miracle. The family experience participating in the process of withdrawal of LST happened for families "in their own time." The results of this study have important implications for clinical practice and future research.

In Their Own Time: The Family Experience during the Process of Withdrawal of Life-Sustaining Therapy

Science.gov (United States)

2008-01-01

Abstract Withdrawal of life-sustaining therapy (LST) occurs commonly in critical care units, yet little is known about the family experience with this process. The purpose of this study was to understand the lived experience of families participating in the process of withdrawal of LST from a family member with an unexpected, life-threatening illness or injury. A hermeneutic phenomenological approach was used as nineteen families were interviewed and observed. Within and across family analyses were conducted. Methodological rigor was established and redundancy was achieved. The categories that evolved from the data included: this happens to other families, time to understand the severity of the illness or injury, time to see if health would be restored, riding a roller coaster, family readiness: willingness to consider withdrawal of LST as a possible option, one step at a time, family readiness: time to make a decision, the family will go on, and waiting for a miracle. The family experience participating in the process of withdrawal of LST happened for families “in their own time.” The results of this study have important implications for clinical practice and future research. PMID:18980452

The devil is in the details: the seven deadly sins of organizing and continuing interprofessional education in the US.

Science.gov (United States)

Clark, Phillip G

2011-09-01

In spite of increased calls for expanding interprofessional practice (IPP) in the US health care system to address concerns about patient safety and quality of care, there has not been a corresponding dramatic growth in interprofessional education (IPE) programs. Indeed, the history of IPE in the US has been a roller-coaster ride of gains and losses, successes and failures. Understanding why this has been so requires the development of a personal and political economy framework, based on an understanding of the structural, ideological, and economic factors and forces that characterize IPE in American higher education. Using a metaphor of the seven deadly sins (lust, pride, greed, gluttony, envy, sloth, and wrath), this discussion focuses on both things that should not be done (sins of commission) and those that should be done but are not (sins of omission) to create successful and sustainable IPE programs. Taken together, these factors help to frame a perspective on IPE that highlights the essential knowledge, attitudes, and skills needed by faculty and administrators to create, implement, and - most importantly - sustain successful programs. Implications of this framework for promoting increased IPE are discussed, particularly with respect to insuring its successful continuation into the future.

Comparative Analysis of Predictive Models of Pain Level from Work-Related Musculoskeletal Disorders among Sewing Machine Operators in the Garments Industry

Directory of Open Access Journals (Sweden)

Carlos Ignacio P. Luga

2017-02-01

Full Text Available The Philippine garments industry has been experiencing a roller-coaster ride during the past decades, with much competition from its Asian neighbors, especially in the wake of the ASEAN 2015 Integration. One of the areas in the industry which can be looked into and possibly improved is the concern on Work-related Musculoskeletal Disorders (WMSDs. Literatures have shown that pain from WMSDs among sewing machine operators in this industry is very prevalent and its effects on the same operators have been very costly. After identifying the risk factors which may cause pain from WMSDs, this study generated three models which would predict the said pain level. These models were analyzed, compared and the best model was identified to make the most accurate prediction of pain level. This predictive model would be helpful for management of garment firms since first, the risk factors have been identified and hence can be used as bases for proposed improvements. Second, the prediction of each operator’s pain level would allow management to assess better its employees in terms of their sewing capacity vis-à-vis the company’s production plans.

Roller compaction of moist pharmaceutical powders.

Science.gov (United States)

Wu, C-Y; Hung, W-L; Miguélez-Morán, A M; Gururajan, B; Seville, J P K

2010-05-31

The compression behaviour of powders during roller compaction is dominated by a number of factors, such as process conditions (roll speed, roll gap, feeding mechanisms and feeding speed) and powder properties (particle size, shape, moisture content). The moisture content affects the powder properties, such as the flowability and cohesion, but it is not clear how the moisture content will influence the powder compression behaviour during roller compaction. In this study, the effect of moisture contents on roller compaction behaviour of microcrystalline cellulose (MCC, Avicel PH102) was investigated experimentally. MCC samples of different moisture contents were prepared by mixing as-received MCC powder with different amount of water that was sprayed onto the powder bed being agitated in a rotary mixer. The flowability of these samples were evaluated in terms of the poured angle of repose and flow functions. The moist powders were then compacted using the instrumented roller compactor developed at the University of Birmingham. The flow and compression behaviour during roller compaction and the properties of produced ribbons were examined. It has been found that, as the moisture content increases, the flowability of moist MCC powders decreases and the powder becomes more cohesive. As a consequence of non-uniform flow of powder into the compaction zone induced by the friction between powder and side cheek plates, all produced ribbons have a higher density in the middle and lower densities at the edges. For the ribbons made of powders with high moisture contents, different hydration states across the ribbon width were also identified from SEM images. Moreover, it was interesting to find that these ribbons were split into two halves. This is attributed to the reduction in the mechanical strength of moist powder compacts with high moisture contents produced at high compression pressures. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Salmonella transfer during pilot plant scale washing and roller conveying of tomatoes.

Science.gov (United States)

Wang, Haiqiang; Ryser, Elliot T

2014-03-01

Salmonella transfer during washing and roller conveying of inoculated tomatoes was quantified using a pilot scale tomato packing line equipped with plastic, foam, or brush rollers. Red round tomatoes (2.3 kg) were dip inoculated with Salmonella enterica serovar Typhimurium LT2 (avirulent) (4 log CFU/g), air dried for 2 h, and then washed in sanitizer-free water for 2 min. Inoculated tomatoes were then passed single file over a 1.5-m conveyor equipped with plastic, foam, or brush rollers followed by 25 previously washed uninoculated tomatoes. Tomato samples were collected after 2 min of both washing and roller conveying, with all 25 uninoculated tomatoes collected individually after conveying. Roller surface samples were collected before and after conveying the uninoculated tomatoes. Both tomato and surface samples were quantitatively examined for Salmonella by direct plating or membrane filtration using xylose lysine Tergitol 4 agar. Regardless of the roller type, Salmonella populations on inoculated tomatoes did not significantly (P conveyors. After conveying uninoculated tomatoes over contaminated foam rollers, 96% of the 25 tomatoes were cross-contaminated with Salmonella at >100 CFU per tomato. With plastic rollers, 24 and 76% of tomatoes were cross-contaminated with Salmonella at 10 to 100 and 1 to 10 CFU per tomato, respectively. In contrast, only 8% of 25 tomatoes were cross-contaminated with brush rollers with Salmonella populations of 1 to 10 CFU per tomato. Overall, cross-contamination was greatest with foam, followed by plastic and brush rollers (P < 0.05). Adding peroxyacetic acid or chlorine to the wash water significantly decreased cross-contamination during tomato conveying, with chlorine less effective in controlling Salmonella on foam compared with plastic and brush rollers.

Errors of car wheels rotation rate measurement using roller follower on test benches

Science.gov (United States)

Potapov, A. S.; Svirbutovich, O. A.; Krivtsov, S. N.

2018-03-01

The article deals with rotation rate measurement errors, which depend on the motor vehicle rate, on the roller, test benches. Monitoring of the vehicle performance under operating conditions is performed on roller test benches. Roller test benches are not flawless. They have some drawbacks affecting the accuracy of vehicle performance monitoring. Increase in basic velocity of the vehicle requires increase in accuracy of wheel rotation rate monitoring. It determines the degree of accuracy of mode identification for a wheel of the tested vehicle. To ensure measurement accuracy for rotation velocity of rollers is not an issue. The problem arises when measuring rotation velocity of a car wheel. The higher the rotation velocity of the wheel is, the lower the accuracy of measurement is. At present, wheel rotation frequency monitoring on roller test benches is carried out by following-up systems. Their sensors are rollers following wheel rotation. The rollers of the system are not kinematically linked to supporting rollers of the test bench. The roller follower is forced against the wheels of the tested vehicle by means of a spring-lever mechanism. Experience of the test bench equipment operation has shown that measurement accuracy is satisfactory at small rates of vehicles diagnosed on roller test benches. With a rising diagnostics rate, rotation velocity measurement errors occur in both braking and pulling modes because a roller spins about a tire tread. The paper shows oscillograms of changes in wheel rotation velocity and rotation velocity measurement system’s signals when testing a vehicle on roller test benches at specified rates.

Engine testing of ceramic cam-roller followers. Final report

Energy Technology Data Exchange (ETDEWEB)

Kalish, Y. [Detroit Diesel Corp., MI (United States)

1992-04-01

For several years, DDC has been developing monolithic ceramic heat engine components. One of the components, developed for an application in our state-of-the-art on-highway, heavy-duty diesel engine, the Series 60, is a silicon nitride cam-roller follower. Prior to starting this program, each valve train component in the Series 60 was considered for conversion to a ceramic material. Many advantages and disadvantages (benefits and risks) were considered. From this effort, one component was selected, the cam-roller follower. Using a system design approach, a ceramic cam-roller follower offered functional improvement at a reasonable cost. The purpose of the project was to inspect and test 100 domestically produced silicon nitride cam-roller followers built to the requirements of the DDC series 60 engine.

EVALUATION OF A LOW FRICTION - HIGH EFFICIENCY ROLLER BEARING ENGINE

Energy Technology Data Exchange (ETDEWEB)

Kolarik, Robert V. II; Shattuck, Charles W.; Copper, Anthony P.

2009-06-30

This Low Friction (High Efficiency Roller Bearing) Engine (LFE) report presents the work done by The Timken Company to conduct a technology demonstration of the benefits of replacing hydrodynamic bearings with roller bearings in the crankshaft and camshaft assemblies of an internal combustion engine for the purpose of collecting data sufficient to prove merit. The engines in the present study have been more extensively converted to roller bearings than any previous studies (40 needle roller bearings per engine) to gain understanding of the full potential of application of bearing technology. The project plan called for comparative testing of a production vehicle which was already respected for having demonstrated low engine friction levels with a rollerized version of that engine. Testing was to include industry standard tests for friction, emissions and fuel efficiency conducted on instrumented dynamometers. Additional tests for fuel efficiency, cold start resistance and other measures of performance were to be made in the actual vehicle. Comparative measurements of noise, vibration and harshness (NVH), were planned, although any work to mitigate the suspected higher NVH level in the rollerized engine was beyond the scope of this project. Timken selected the Toyota Avalon with a 3.5L V-6 engine as the test vehicle. In an attempt to minimize cost and fabrication time, a ‘made-from’ approach was proposed in which as many parts as possible would be used or modified from production parts to create the rollerized engine. Timken commissioned its test partner, FEV Engine Technology, to do a feasibility study in which they confirmed that using such an approach was possible to meet the required dimensional restrictions and tolerances. In designing the roller bearing systems for the crank and cam trains, Timken utilized as many production engine parts as possible. The crankshafts were produced from production line forgings, which use Timken steel, modified with special

Direct fabrication of rigid microstructures on a metallic roller using a dry film resist

International Nuclear Information System (INIS)

Jiang, Liang-Ting; Huang, Tzu-Chien; Chang, Chih-Yuan; Ciou, Jian-Ren; Yang, Sen-Yeu; Huang, Po-Hsun

2008-01-01

This paper presents a novel method to fabricate a metallic roller mold with microstructures on its surface using a dry film resist (DFR). The DFR is laminated uniformly onto the curvy surface of a copper roller. After that, the micro-scale photoresist on the surface of the roller can be patterned by non-planar lithography using a flexible film photomask, followed by ferric chloride wet etching to obtain the desired microstructures. This method overcomes the uniformity issue of photoresist coating on rollers, and solves the molds sliding problem during the embossing process because the microstructures are fabricated directly on the roller surface. Furthermore, the rigid metallic roller mold has excellent strength durability and temperature endurance, which can be used in roller hot embossing with a high embossing pressure. The fabricated microstructure roller mold is used as a mold in the hybrid extrusion roller embossing process and successfully fabricates uniform micro-scale prominent line arrays on PC films. This result proves that the roller fabricated by this method can be successfully used in roller embossing for microstructure mass production. The excellent flatness of dry film resist laminating is the key in this fabrication process. The flexible film photomask can be easily designed using CAD software; this roller fabrication method enhances the design flexibility and reduces the cost and time

Roller Locking Brake

Science.gov (United States)

Vranish, John M.

1993-01-01

Roller locking brake is normally braking rotary mechanism allowing free rotation when electromagnet in mechanism energized. Well suited to robots and other machinery which automatic braking upon removal of electrical power required. More compact and reliable. Requires little electrical power to maintain free rotation and exhibits minimal buildup of heat.

KINEMATICS AND DYNAMICS MODELS OF CYLINDRICAL ROLLER BEARING OF RAILWAY TRANSPORT

Directory of Open Access Journals (Sweden)

A. V. Gaydamaka

2014-05-01

Full Text Available Purpose. Lack of kinematics models and imperfection of the known dynamics models of the roller bearings of railway rolling stock axle-boxes do not allow designing the optimal structure of bearing cages, providing the required service life and reliability of bearing units of wheel sets for cars and locomotives. The studies of kinematics and dynamics of roller bearings of axle boxes for cars and locomotives and modeling of their parts interaction to create the analytical method of bearing cages calculation are necessary. Methodology. This purpose has been achieved due to the modeling of kinematics of the ideal (without gaps and real (taking account the gaps, manufacturing and installation errors bearings, substantiation of the transfer mechanism of motion from the rollers to bearing cage, modeling the dynamics of rolling, research of interaction forces of the rollers with bearing cage. Findings. It is established that the kinematics of ideal bearing is determined by the contact deformations of the rollers and rings, when the kinematics of real bearing depends mainly on the side gaps in the windows of the bearing cage. On the basis of studies of the real bearing kinematics the dynamics models of the rollers and bearing cage interaction were constructed. The conducted studies of kinematics and dynamics of rolling bearings have changed our view of them as of the planetary mechanism, explained the reason of bearing cage loading, and confirmed the possibility of destruction during operation. Originality. It was first proposed a mechanism for motion transfer from the rollers to the bearing cage of roller bearings, consisting in that the side gap in the bearing cage window is reduced gradually multiple of the number of rollers of radial loading area according to the bearing cage motion. The models of roller bearing dynamics, which allow calculating the interaction forces of parts for all modes of operation, were improved. Practical value. Use of the

Air Monitoring Network at Tonopah Test Range: Network Description, Capabilities, and Analytical Results

International Nuclear Information System (INIS)

Hartwell, William T.; Daniels, Jeffrey; Nikolich, George; Shadel, Craig; Giles, Ken; Karr, Lynn; Kluesner, Tammy

2012-01-01

During the period April to June 2008, at the behest of the Department of Energy (DOE), National Nuclear Security Administration, Nevada Site Office (NNSA/NSO); the Desert Research Institute (DRI) constructed and deployed two portable environmental monitoring stations at the Tonopah Test Range (TTR) as part of the Environmental Restoration Project Soils Activity. DRI has operated these stations since that time. A third station was deployed in the period May to September 2011. The TTR is located within the northwest corner of the Nevada Test and Training Range (NTTR), and covers an area of approximately 725.20 km2 (280 mi2). The primary objective of the monitoring stations is to evaluate whether and under what conditions there is wind transport of radiological contaminants from Soils Corrective Action Units (CAUs) associated with Operation Roller Coaster on TTR. Operation Roller Coaster was a series of tests, conducted in 1963, designed to examine the stability and dispersal of plutonium in storage and transportation accidents. These tests did not result in any nuclear explosive yield. However, the tests did result in the dispersal of plutonium and contamination of surface soils in the surrounding area.

Physiological demands of off-road vehicle riding.

Science.gov (United States)

Burr, Jamie F; Jamnik, Veronica K; Shaw, Jim A; Gledhill, Norman

2010-07-01

The purpose of this study was to characterize the physiological demands of recreational off-road vehicle riding under typical riding conditions using habitual recreational off-road vehicle riders (n = 128). Comparisons of the physical demands of off-road vehicle riding were made between vehicle types (all-terrain vehicle (ATV) and off-road motorcycle (ORM)) to the demands of common recreational activities. Habitual riders (ATV = 56, ORM = 72) performed strength assessments before and after a representative trail ride (48 +/- 24.2 min), and ambulatory oxygen consumption was measured during one lap (24.2 +/- 11.8 min) of the ride. The mean VO2 requirement (mL x kg(-1) x min(-1)) while riding an off-road vehicle was 12.1 +/- 4.9 for ATV and 21.3 +/- 7.1 for ORM (P = 0.002), which is comparable to the VO2 required of many common recreational activities. Temporal analysis of activity intensity revealed approximately 14% of an ATV ride and 38% of an ORM ride are within the intensity range (940% VO2 reserve) required to achieve changes in aerobic fitness. Riding on a representative course also led to muscular fatigue, particularly in the upper body. On the basis of the measured metabolic demands, evidence of muscular strength requirements, and the associated caloric expenditures with off-road vehicle riding, this alternative form of activity conforms to the recommended physical activity guidelines and can be effective for achieving beneficial changes in health and fitness.

A study on rheological characteristics of roller milled fenugreek fractions.

Science.gov (United States)

Sakhare, Suresh D; Inamdar, Aashitosh A; Prabhasankar, P

2016-01-01

Fenugreek seeds were fractionated by roller milling to get various fractions. The roller milled fractions and whole fenugreek flour (WFF) were evaluated for the flow behavior and time-dependent flow properties using a rotational viscometer at the temperatures of 10-60 (0)C. The samples subjected to a programmed shear rate increase linearly from 0 to 300 s(-1) in 3 min and successive decrease linearly shear rate from 300 s(-1) to 0 in 3 min. The roller milled fractions and WFF paste exhibited non-Newtonian pseudoplastic behavior. Difference in hysteresis loop area was observed among the roller milled fractions and WFF, being more noticeable at lower temperatures. Power law and Casson models were used to predict flow properties of samples. The power law model described well the flow behavior of the roller milled fractions and WFF at temperatures tested. Except flour (FL) fraction, consistency coefficient, m, increased with the temperature both in the forward and backward measurements. The roller milled fractions and WFF exhibited rheopectic behavior that increased viscosity with increasing the shear speed and the temperature. For all the sample tested, initial shear stress increased with increase in shear rate and temperature.

14 CFR 23.1399 - Riding light.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Riding light. 23.1399 Section 23.1399... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Equipment Lights § 23.1399 Riding light. (a) Each riding (anchor) light required for a seaplane or amphibian, must be installed so that it...

14 CFR 27.1399 - Riding light.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Riding light. 27.1399 Section 27.1399... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Lights § 27.1399 Riding light. (a) Each riding light required for water operation must be installed so that it can— (1) Show a white light for at least two...

14 CFR 29.1399 - Riding light.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Riding light. 29.1399 Section 29.1399... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Lights § 29.1399 Riding light. (a) Each riding light required for water operation must be installed so that it can— (1) Show a white light for at least two...

14 CFR 25.1399 - Riding light.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Riding light. 25.1399 Section 25.1399... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1399 Riding light. (a) Each riding (anchor) light required for a seaplane or amphibian must be installed so that it can— (1) Show a white light for...

Armed rollers: does nestling's vomit function as a defence against predators?

Directory of Open Access Journals (Sweden)

Deseada Parejo

Full Text Available Chemical defences against predators are widespread in the animal kingdom although have been seldom reported in birds. Here, we investigate the possibility that the orange liquid that nestlings of an insectivorous bird, the Eurasian roller (Coracias garrulus, expel when scared at their nests acts as a chemical defence against predators. We studied the diet of nestling rollers and vomit origin, its chemical composition and deterrent effect on a mammal generalist predator. We also hypothesized that nestling rollers, as their main prey (i.e. grasshoppers do from plants, could sequester chemicals from their prey for their use. Grasshoppers, that also regurgitate when facing to a threat, store the harmful substances used by plants to defend themselves against herbivores. We found that nestling rollers only vomit after being grasped and moved. The production of vomit depended on food consumption and the vomit contained two deterrent chemicals (hydroxycinnamic and hydroxybenzoic acids stored by grasshoppers and used by plants to diminish herbivory, suggesting that they originate from the rollers' prey. Finally, we showed for the first time that the oral secretion of a vertebrate had a deterrent effect on a model predator because vomit of nestling rollers made meat distasteful to dogs. These results support the idea that the vomit of nestling rollers is a chemical defence against predators.

48 CFR 225.7009 - Restriction on ball and roller bearings.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Restriction on ball and roller bearings. 225.7009 Section 225.7009 Federal Acquisition Regulations System DEFENSE ACQUISITION... roller bearings. ...

A Methodology of Designing the Teeth Conjugation in a Planetary Roller Screw

Directory of Open Access Journals (Sweden)

Lisowski Filip

2016-12-01

Full Text Available The paper presents the methodology for designing the teeth conjunction of planetary gears in the planetary roller screw mechanism. A function of the planetary gears is to synchronize an operation of rollers in order to avoid axial displacements. A condition of the correct operation is no axial movement of rollers in relation to the nut. The planetary gears are integral parts of rollers and therefore an operation of the gear transmissions has a direct impact on cooperation of the screw, rollers and the nut. The proper design of gear engagements is essential for reducing slippage on surfaces of the cooperating threaded elements. For this purpose, in a designing method, both the limitations of operation and kinematic conditions of rollers’ operation have to be taken into account.

Skateboarding: more dangerous than roller skating or in-line skating.

Science.gov (United States)

Osberg, J S; Schneps, S E; Di Scala, C; Li, G

1998-10-01

To describe the circumstances, severity, and outcomes of skating-related injuries among children admitted to trauma centers. A cross-sectional comparison of roller skaters (n = 154), in-line skaters (n = 190), and skateboarders (n = 254) aged 5 to 19 years who were hospitalized with injuries. Seventy-nine hospitals and pediatric trauma centers participating in the National Pediatric Trauma Registry between October 1988 and April 1997. Three quarters (75.8%) of the study sample were male, nearly half (47.8%) were injured on roads, and more than one third (37.1%) had head injuries. Among skateboarders, 50.8% had head injuries compared with 33.7% of in-line skaters and 18.8% of roller skaters (Pskateboarders were 8 times more likely to be severe or critical compared with roller skaters' injuries and more than 2 times as likely to be severe or critical compared with in-line skaters' injuries. Mean hospital length of stay was 6.0 days for skateboarders, 3.4 days for in-line skaters, and 2.4 days for roller skaters (PSkateboarders were more likely to be male and to be injured on roads than were in-line skaters or roller skaters. Skateboarding-related injuries are more severe and have more serious consequences than roller skating or in-line skating injuries. Research is needed to identify ergonomic and behavioral factors responsible for higher head injury risk to skateboarders, and interventions are needed to reduce the risk.

Impact Analysis of Roller System Stability for Four-High Mill Horizontal Vibration

Directory of Open Access Journals (Sweden)

Xiao-bin Fan

2016-01-01

Full Text Available In order to study the hot Compact Strip Production (CSP, four-high mill vibration characteristics, and vibration suppression method, the roller system structure stability was analyzed and calculated at first in the paper. And then, the mill stand gap was measured at field and its influence on roll transverse vibration was analyzed. The drum gear coupling effect on the roller system stability and the automatic balance conditions of the coupling transmission torque were studied; the influence of axial force caused by the roller cross on the system stability was analyzed. Finally, the roller transverse friction chatter vibration mechanics model was established; the simulation analysis was carried out with eliminating mill house-bearing clearance and adding floating support for coupling, respectively. And the characteristics of the roller “jump vibration” were studied. We applied copper gaskets to eliminate or reduce mill house-bearing clearance for suppressing the rolling mill vibration on the spot; the test results show that the roller transverse vibration was suppressed after eliminating clearance.

Behavior and Development: Physical Development--"Riding Along" Outdoors!

Science.gov (United States)

Strickland, Eric

2005-01-01

Riding toys and push-pull toys are traditionally part of every early childhood program. Young children can develop a wide variety of skills and get numerous health benefits from riding toys if one is careful and thoughtful in setting up the riding-toy area. This article describes various types of riding toys and activity ideas to enhance…

Evaluating Experiences in Different Virtual Reality Setups

OpenAIRE

Settgast , Volker; Pirker , Johanna; Lontschar , Stefan; Maggale , Stefan; Gütl , Christian

2016-01-01

Part 2: Use and Evaluation of Digital Entertainment; International audience; This paper describes the evaluation of three different scenarios in the fully immersive room-based virtual environment DAVE (Definitely Affordable Virtual Environment) and a head-mounted display, the Oculus Rift. The evaluation focuses on comparing the two immersive environments and three different scenarios (observation, emotion in a roller coaster, and interaction) in regards to typical virtual-reality characterist...

Standard test method for measurement of web/roller friction characteristics

CERN Document Server

American Society for Testing and Materials. Philadelphia

2003-01-01

1.1 This test method covers the simulation of a roller/web transport tribosystem and the measurement of the static and kinetic coefficient of friction of the web/roller couple when sliding occurs between the two. The objective of this test method is to provide users with web/roller friction information that can be used for process control, design calculations, and for any other function where web/roller friction needs to be known. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Improvement of Railroad Roller Bearing Test Procedures & Development of Roller Bearing Diagnostic Techniques. Volume 2.

Science.gov (United States)

1982-04-01

A comprehensive review of existing basic diagnostic techniques applicable to the railcar roller bearing defect and failure problem was made. Of the potentially feasible diagnostic techniques identified, high frequency vibration was selected for exper...

48 CFR 252.225-7016 - Restriction on acquisition of ball and roller bearings.

Science.gov (United States)

2010-10-01

... of ball and roller bearings. 252.225-7016 Section 252.225-7016 Federal Acquisition Regulations System... and roller bearings. As prescribed in 225.7009-5, use the following clause: Restriction on Acquisition of Ball and Roller Bearings (MAR 2006) (a) Definitions. As used in this clause' (1) Bearing...

Improving feeding powder distribution to the compaction zone in the roller compaction.

Science.gov (United States)

Yu, Mingzhe; Omar, Chalak; Schmidt, Alexander; Litster, James D; Salman, Agba D

2018-07-01

In the roller compaction process, powder flow properties have a significant influence on the uniformity of the ribbon properties. The objective of this work was to improve the powder flow in the feeding zone by developing novel feeding guiders which are located in the feeding zone close to the rollers in the roller compactor (side sealing system). Three novel feeding guiders were designed by 3D printing and used in the roller compactor, aiming to control the amount of powder passing across the roller width. The new feeding guiders were used to guide more powder to the sides between the rollers and less powder to the centre comparing to the original feeding elements. Temperature profile and porosity across the ribbon width indicated the uniformity of the ribbon properties. Using the novel feeding guiders resulted in producing ribbons with uniform temperature profile and porosity distribution across the ribbon width. The design of the feeding guiders contributed to improving the tensile strength of the ribbons produced from the compaction stage as well as reducing the fines produced from the crushing stage. Copyright © 2018 Elsevier B.V. All rights reserved.

A roller chain drive model including contact with guide-bars

DEFF Research Database (Denmark)

Pedersen, Sine Leergaard; Hansen, John Michael; Ambrósio, J. A. C.

2004-01-01

A model of a roller chain drive is developed and applied to the simulation and analysis of roller chain drives of large marine diesel engines. The model includes the impact with guide-bars that are the motion delimiter components on the chain strands between the sprockets. The main components...... and the sprocket centre, i.e. a constraint is added when such distance is less than the pitch radius. The unilateral kinematic constraint is removed when its associated constraint reaction force, applied on the roller, is in the direction of the root of the sprocket teeth. In order to improve the numerical...

Simulated self-motion in a visual gravity field: sensitivity to vertical and horizontal heading in the human brain.

Science.gov (United States)

Indovina, Iole; Maffei, Vincenzo; Pauwels, Karl; Macaluso, Emiliano; Orban, Guy A; Lacquaniti, Francesco

2013-05-01

Multiple visual signals are relevant to perception of heading direction. While the role of optic flow and depth cues has been studied extensively, little is known about the visual effects of gravity on heading perception. We used fMRI to investigate the contribution of gravity-related visual cues on the processing of vertical versus horizontal apparent self-motion. Participants experienced virtual roller-coaster rides in different scenarios, at constant speed or 1g-acceleration/deceleration. Imaging results showed that vertical self-motion coherent with gravity engaged the posterior insula and other brain regions that have been previously associated with vertical object motion under gravity. This selective pattern of activation was also found in a second experiment that included rectilinear motion in tunnels, whose direction was cued by the preceding open-air curves only. We argue that the posterior insula might perform high-order computations on visual motion patterns, combining different sensory cues and prior information about the effects of gravity. Medial-temporal regions including para-hippocampus and hippocampus were more activated by horizontal motion, preferably at constant speed, consistent with a role in inertial navigation. Overall, the results suggest partially distinct neural representations of the cardinal axes of self-motion (horizontal and vertical). Copyright © 2013 Elsevier Inc. All rights reserved.

Phylogenetic relationships of rollers (Coraciidae) based on complete mitochondrial genomes and fifteen nuclear genes.

Science.gov (United States)

Johansson, Ulf S; Irestedt, Martin; Qu, Yanhua; Ericson, Per G P

2018-04-06

The rollers (Coraciidae) constitute a relative small avian family with ca. 12 species distributed in Africa, western and southern Eurasia, and eastern Australia. In this study we examine the phylogenetic relationships of all species currently recognized in the family, including two taxa whose taxonomic status is currently contested. By using shotgun sequencing on degraded DNA from museum study skins we have been able to recover complete mitochondrial genomes as well as 15 nuclear genes for in total 16 taxa. The gene sequences were analyzed both concatenated in a maximum likelihood framework as well in a species tree approach using MP-EST. The different analytical approaches yield similar, highly supported trees and support the current division of the rollers into two genera, Coracias and Eurystomus. The only conflict relates to the placement of the Blue-bellied Roller (C. cyanogaster), where the mitochondrial, and the concatenated nuclear and mitochondrial data set, place this taxon as sister to the other Coracias species, whereas nuclear data and the species tree analysis place it as the sister taxon of C. naevia and C. spatulatus. All analyses place the Eurasian roller (C. garrulus) with the two African species, Abyssinian Roller (C. abyssinica) and Liliac-breasted Roller (C. caudatus), and place this clade as the sister group to the Asian Coracias rollers. In addition, our results support a sister group relationship between the morphologically rather dissimilar Purple Roller (C. naevia) and Racquet-tailed Roller (C. spatulatus) and also support the division of Eurystomus in an African and an Asian clade. However, within the Asian clade the Azure Roller (E. azureus) from Halmahera appears to be nested within the Dollarbird (E. orientalis), indicating that that this taxon is a morphological divergent, but a rather recent offshoot, of the widespread Dollarbird. Similarly, the Purple-winged Roller (C. temminickii) from Sulawesi group together with C. benghalensis

Nanocrystalline, superhard, ductile ceramic coatings for roller-cone bit bearings

Energy Technology Data Exchange (ETDEWEB)

Namavar, F.; Colter, P.; Karimy, H. [Spire Corp., Bedford, MA (United States)] [and others

1997-12-31

The established method for construction of roller bits utilizes carburized steel, frequently with inserted metal bearing surfaces. This construction provides the necessary surface hardness while maintaining other desirable properties in the core. Protective coatings are a logical development where enhanced hardness, wear resistance, corrosion resistance, and surface properties are required. The wear properties of geothermal roller-cone bit bearings could be further improved by application of protective ceramic hard coatings consisting of nanometer-sized crystallites. Nanocrystalline protective coatings provide the required combination of hardness and toughness which has not been available thus far using traditional ceramics having larger grains. Increased durability of roller-cone bit bearings will ultimately reduce the cost of drilling geothermal wells through increased durability.

[Riding therapy in the rehabilitation of mobility-impaired children].

Science.gov (United States)

Mäenpää, Helena; Kela, Katri; Sätilä, Heli

2016-01-01

Riding therapy is a comprehensive and functional form of rehabilitation, in which the rehabilitee, the horse and the riding therapist collaborate in order to achieve individually assigned goals that support rehabilitation. In Finland, riding therapy is therapeutic rehabilitation carried out by riding therapists who have undergone approved training. The therapy is mainly implemented in an individual form, but small group working is also applied, e.g. in the form of pair therapy and therapeutic vaulting. In Europe, this form of rehabilitation has been divided into hippotherapy supporting motor functions and heilpedagogical riding therapy functioning in support of upbringing.

On-line single server dial-a-ride problems

NARCIS (Netherlands)

Feuerstein, E.; Stougie, L.

1998-01-01

In this paper results on the dial-a-ride problem with a single server are presented. Requests for rides consist of two points in a metric space, a source and a destination. A ride has to be made by the server from the source to the destination. The server travels at unit speed in the metric space

Analisis Industri Bisnis Jasa Online Ride Sharing di Indonesia

Directory of Open Access Journals (Sweden)

Berto Mulia Wibawa

2018-03-01

Full Text Available Analysis of Online Ride Sharing Business Industry in IndonesiaInnovation in transportation sector with sharing economy principal has create new service sector which is named online ride sharing service. There are a lot of online ride-sharing service players in Indonesia such as Go-Jek, Grab, and Uber. Nowadays, government also have rules on changing the condition of online ride-sharing. Therefore, industry analysis is needed to be analyze further to know the industry attractiveness of the online-ride sharing service. This study aims to analyze the level of attractiveness in online ride-sharing industry in Indonesia. This study used descriptive-explorative method on identifying Porter’s Five Forces as tools in industry analysis. Data collection is using ghost interview method to the selected driver. The conclusion is online-ride sharing industry in Indonesia is quite attractive to be developed in the future because the number of customers has not reached the maximum point, moreover the industry may offer a very diverse product differentiationDOI: 10.15408/ess.v8i1.5739

Elevator ride comfort monitoring and evaluation using smartphones

Science.gov (United States)

Zhang, Yang; Sun, Xiaowei; Zhao, Xuefeng; Su, Wensheng

2018-05-01

With rapid urbanization, the demand for elevators is increasing, and their level of safety and ride comfort under vibrating conditions has also aroused interest. It is therefore essential to monitor the ride comfort level of elevators. The traditional method for such monitoring depends significantly on regular professional inspections, and requires expensive equipment and professional skill. With this regard, a new method for elevator ride comfort monitoring using a smartphone is demonstrated herein in detail. A variety of high-precision sensors are installed in a smartphone with strong data processing and telecommunication capabilities. A series of validation tests were designed and completed, and the international organization for standardization ISO2631-1997 was applied to evaluate the level of elevator ride comfort. Experimental results indicate that the proposed method is stable and reliable, its precision meets the engineering requirements, and the elevator ride comfort level can be accurately monitored under various situations. The method is very economical and convenient, and provides the possibility for the public to participate in elevator ride comfort monitoring. In addition, the method can both provide a wide range of data support and eliminate data errors to a certain extent.

On Working Capacity Criteria for Screw-Roller Mechanisms

Directory of Open Access Journals (Sweden)

D. S. Blinov

2015-01-01

Full Text Available Today roller-screw mechanisms (RSM are the most prospective motion converters from rotary to linear type. RSM manufacturers have suggested their design in the way, similar to the rolling bearings, in static and dynamic load ratings. The latter means that during long operations the main criterion of the RSM working capacity is fatigue spalling. However, this approach does not permit to consider temporal changes of the most critical performance parameters of the RSM (such as the axial play, the efficiency factor, the axial stiffness, the accuracy, the starting torque force for zero lash RSMs, etc. through calculations. The abovementioned method was not perfect, because the choice of the main criterion of RSM working capacity was wrong. The article proves that wear-resistance is the main criterion of RSM working capacity. The proof is the RSM efficiency factor equal to 80-88% on the average. The power loss occurs because of overcoming a sliding friction between multiple (from 300 to 1000 interfacing turns of thread on the screw and the rollers as well as on the rollers and the nut. That is why the RSMs are the screwtype rolling mechanisms with an essential portion of sliding friction. High-accuracy measurements taken using the device called a form-tracer for threaded pieces permitted to determine the essential changes on the profiles of turns of threads on the rollers (a straight-line portion appeared on the radial profile; these changes could emerge only from wear. Besides, the length of this portion increased with the increasing RSM operation time. The JSC “Moskvich” has examined the RSMs, which have been put out of operation after completing their service life as parts of robot welding machines. There were no traces of fatigue spalling found on the threaded surfaces of the RSM parts, while the sizes of the straight-line portions on the turns of the roller threads were much bigger than they were during the measurements after the initial

Fast EEMD Based AM-Correntropy Matrix and Its Application on Roller Bearing Fault Diagnosis

Directory of Open Access Journals (Sweden)

Yunxiao Fu

2016-06-01

Full Text Available Roller bearing plays a significant role in industrial sectors. To improve the ability of roller bearing fault diagnosis under multi-rotating situation, this paper proposes a novel roller bearing fault characteristic: the Amplitude Modulation (AM based correntropy extracted from the Intrinsic Mode Functions (IMFs, which are decomposed by Fast Ensemble Empirical mode decomposition (FEEMD and employ Least Square Support Vector Machine (LSSVM to implement intelligent fault identification. Firstly, the roller bearing vibration acceleration signal is decomposed by FEEMD to extract IMFs. Secondly, IMF correntropy matrix (IMFCM as the fault feature matrix is calculated from the AM-correntropy model of the primary vibration signal and IMFs. Furthermore, depending on LSSVM, the fault identification results of the roller bearing are obtained. Through the bearing identification experiments in stationary rotating conditions, it was verified that IMFCM generates more stable and higher diagnosis accuracy than conventional fault features such as energy moment, fuzzy entropy, and spectral kurtosis. Additionally, it proves that IMFCM has more diagnosis robustness than conventional fault features under cross-mixed roller bearing operating conditions. The diagnosis accuracy was more than 84% for the cross-mixed operating condition, which is much higher than the traditional features. In conclusion, it was proven that FEEMD-IMFCM-LSSVM is a reliable technology for roller bearing fault diagnosis under the constant or multi-positioned operating conditions, and as such, it possesses potential prospects for a broad application of uses.

Edgewise vibration control of wind turbine blades using roller and liquid dampers

DEFF Research Database (Denmark)

Zhang, Zili; Nielsen, Søren R.K.

2014-01-01

suppressing edgewise vibrations. The roller dampers are more volumetrically efficient due to the higher mass density of the steel comparing with the liquid. On the other hand, TLCDs have their advantage that it is easier to specify the optimum damping of the damper by changing the opening ratio of the orifice......This paper deals with the passive vibration control of edgewise vibrations by means of roller dampers and tuned liquid column dampers (TLCDs). For a rotating blade, the large centrifugal acceleration makes it possible to use roller dampers or TLCDs with rather small masses for effectively...

Edgewise vibration control of wind turbine blades using roller and liquid dampers

International Nuclear Information System (INIS)

Zhang, Z L; Nielsen, S R K

2014-01-01

This paper deals with the passive vibration control of edgewise vibrations by means of roller dampers and tuned liquid column dampers (TLCDs). For a rotating blade, the large centrifugal acceleration makes it possible to use roller dampers or TLCDs with rather small masses for effectively suppressing edgewise vibrations. The roller dampers are more volumetrically efficient due to the higher mass density of the steel comparing with the liquid. On the other hand, TLCDs have their advantage that it is easier to specify the optimum damping of the damper by changing the opening ratio of the orifice. In this paper, 2-DOF nonlinear models are suggested for tuning a roller damper or a TLCD attached to a rotating wind turbine blade, ignoring the coupling between the blade and the tower. The decoupled optimization is verified by incorporating the optimized damper into a more sophisticated 13- DOF wind turbine model with due consideration of the coupled blade-tower-drivetrain vibrations, quasi-static aeroelasticity as well as a collective pitch controller. Performances of the dampers are compared in terms of the control efficiency and the practical applications. The results indicate that roller dampers and TLCDs at optimal tuning can effectively suppress the dynamic response of wind turbine blades

Daylighting performance evaluation of a bottom-up motorized roller shade

Energy Technology Data Exchange (ETDEWEB)

Kapsis, K.; Athienitis, A.K.; Zmeureanu, R.G. [Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, QC (Canada); Tzempelikos, A. [School of Civil Engineering, Purdue University, West Lafayette, IN (United States)

2010-12-15

This paper presents an experimental and simulation study for quantifying the daylighting performance of bottom-up roller shades installed in office spaces. The bottom-up shade is a motorized roller shade that opens from top to bottom operating in the opposite direction of a conventional roller shade, so as to cover the bottom part of the window, while allowing daylight to enter from the top part of the window, reaching deeper into the room. A daylighting simulation model, validated with full-scale experiments, was developed in order to establish correlations between the shade position, outdoor illuminance and work plane illuminance for different outdoor conditions. Then, a shading control algorithm was developed for application in any location and orientation. The validated model was employed for a sensitivity analysis of the impact of shade optical properties and control on the potential energy savings due to the use of daylighting. The results showed that Daylight Autonomy for the bottom-up shade is 8-58% higher compared to a conventional roller shade, with a difference of 46% further away from the facade, where the use of electric lighting is needed most of the time. The potential reduction in energy consumption for lighting is 21-41%. (author)

INFLUENCE CONSTRUCTION OF THE ROLLER ON THE POWER OF THE DRIVE SYSTEM OF THE BELT CONVEYOR

Directory of Open Access Journals (Sweden)

Tadeusz OPASIAK

2014-09-01

Full Text Available The paper presents a study of new design of rollers. The study focused on the measurement of static and dynamic resistance of rotating rollers and the impact of new construction on the power consumption of the belt conveyor. Rollers have been modified through the use of class C4 bearing seals and labyrinth seal U4Exp 62/65 with a cover 2LU4 of runner construction. Measurements of static and dynamic resistance of rotating rollers were made on a universal rollers stand and power measurements were carried out on a belt conveyor power supply system Gwarek 1200 No. TW in mine KWK Mysłowice–Wesoła.

Vaccination against Alzheimer disease: an update on future strategies.

Science.gov (United States)

Fettelschoss, Antonia; Zabel, Franziska; Bachmann, Martin F

2014-01-01

Alzheimer disease is a devastating chronic disease without adequate therapy. More than 10 years ago, it was demonstrated in transgenic mouse models that vaccination may be a novel, disease-modifying therapy for Alzheimer. Subsequent clinical development has been a roller-coaster with some positive and many negative news. Here, we would like to summarize evidence that next generation vaccines optimized for old people and focusing on patients with mild disease stand a good chance to proof efficacious for the treatment of Alzheimer.

Roller compaction: Effect of relative humidity of lactose powder.

Science.gov (United States)

Omar, Chalak S; Dhenge, Ranjit M; Palzer, Stefan; Hounslow, Michael J; Salman, Agba D

2016-09-01

The effect of storage at different relative humidity conditions, for various types of lactose, on roller compaction behaviour was investigated. Three types of lactose were used in this study: anhydrous lactose (SuperTab21AN), spray dried lactose (SuperTab11SD) and α-lactose monohydrate 200M. These powders differ in their amorphous contents, due to different manufacturing processes. The powders were stored in a climatic chamber at different relative humidity values ranging from 10% to 80% RH. It was found that the roller compaction behaviour and ribbon properties were different for powders conditioned to different relative humidities. The amount of fines produced, which is undesirable in roller compaction, was found to be different at different relative humidity. The minimum amount of fines produced was found to be for powders conditioned at 20-40% RH. The maximum amount of fines was produced for powders conditioned at 80% RH. This was attributed to the decrease in powder flowability, as indicated by the flow function coefficient ffc and the angle of repose. Particle Image Velocimetry (PIV) was also applied to determine the velocity of primary particles during ribbon production, and it was found that the velocity of the powder during the roller compaction decreased with powders stored at high RH. This resulted in less powder being present in the compaction zone at the edges of the rollers, which resulted in ribbons with a smaller overall width. The relative humidity for the storage of powders has shown to have minimal effect on the ribbon tensile strength at low RH conditions (10-20%). The lowest tensile strength of ribbons produced from lactose 200M and SD was for powders conditioned at 80% RH, whereas, ribbons produced from lactose 21AN at the same condition of 80% RH showed the highest tensile strength. The storage RH range 20-40% was found to be an optimum condition for roll compacting three lactose powders, as it resulted in a minimum amount of fines in the

The System of Simulation and Multi-objective Optimization for the Roller Kiln

Science.gov (United States)

Huang, He; Chen, Xishen; Li, Wugang; Li, Zhuoqiu

It is somewhat a difficult researching problem, to get the building parameters of the ceramic roller kiln simulation model. A system integrated of evolutionary algorithms (PSO, DE and DEPSO) and computational fluid dynamics (CFD), is proposed to solve the problem. And the temperature field uniformity and the environment disruption are studied in this paper. With the help of the efficient parallel calculation, the ceramic roller kiln temperature field uniformity and the NOx emissions field have been researched in the system at the same time. A multi-objective optimization example of the industrial roller kiln proves that the system is of excellent parameter exploration capability.

Design, development and evaluation of a divergent roller sizer for almond kernels

Directory of Open Access Journals (Sweden)

D Ghanbarian

2015-09-01

Full Text Available Introduction: Iran is one of the major producers of almonds. According to the statistics released by FAO (2011, Iran with more than 110000 tons of almonds is the third in rank throughout the world. However, most Iranian almonds are presented as an unsorted and unpackaged product. Some producers sort their products by hand which is very time-consuming and labor-intensive. So, there is an essential need for suitable grading and packaging machines especially for the export of almond kernels.Grading, which is sometimes called sorting, is basically separating the material in different homogenous groups according to its specific characteristics like size, shape, color and on the basis of quality. Weighing is one of the best methods for grading agricultural products based on size, but due to its high cost and complexity of operations, usage of weigh size sorting machines is practically limited. So, sizing of most agricultural products is accomplished based on their dimensional attributes such as diameter, length, thickness or a combination of them. Field study shows that recently vibrating sizing machines are used for grading almond kernels. This type of sizing machine is huge, expensive, noisy and it consumes a lot of energy. Thus, the main objective of the present study was the design, development and evaluation of a new prototype of an almond kernel sizing machine. Materials and methods: It is important that the machine could resolve defects of existing vibrating machines. It should provide efficient and cost effective sizing for a wide range of kernel sizes and shapes. Furthermore, it should be of simple construction and be able to accept manual feeding. Previously conducted experiments showed that the thickness of the kernel is the most appropriate dimension for its sizing. Among the different types of dimensional sizing machines, the divergent roller grader which grades the products based on their thickness is considered to be one of the simplest

Roller Skating; Physical Education: 9.8414.

Science.gov (United States)

Amacker, Kathy; Mikell, Lenora

GRADES OR AGES: Grades 7-12. SUBJECT MATTER: Methods and procedures of roller skating. ORGANIZATION AND PHYSICAL APPEARANCE: The contents are divided into six areas, which are Course Guidelines, Course Description and Accreditation Standard Broad Goal, Course of Study Behavioral Objectives, Course Content, Learning Activities and Teaching…

Knee joint position sense of roller hockey players: a comparative study.

Science.gov (United States)

Venâncio, João; Lopes, Diogo; Lourenço, Joaquim; Ribeiro, Fernando

2016-06-01

This study aimed to compare knee joint position sense of roller hockey players with an age-matched group of non-athletes. Forty-three male participants voluntarily participated in this cross-sectional study: 21 roller hockey players (mean age: 23.2 ± 4.2 years old, mean weight: 81.8 ± 9.8 kg, mean height: 180.5 ± 4.1 cm) and 22 age-matched non-athletes (mean age: 23.7 ± 3.9 years old, mean weight: 85.0 ± 6.2 kg, mean height: 181.5 ± 5.0 cm). Knee joint position sense of the dominant limb was evaluated using a technique of open-kinetic chain and active knee positioning. Joint position sense was reported using absolute, relative and variable angular errors. The main results indicated that the group of roller hockey players showed significantly lower absolute (2.4 ± 1.2º vs. 6.5 ± 3.2º, p ≤ 0.001) and relative (1.7 ± 2.1º vs. 5.8 ± 4.4º, p ≤ 0.001) angular errors in comparison with the non-athletes group. In conclusion, the results from this present study suggest that proprioceptive acuity, assessed by measuring joint position sense, is increased in roller hockey players. The enhanced proprioception of the roller hockey players could contribute to injury prevention and improved performance during sporting activities.

Feasibility testing for dial-a-ride problems

DEFF Research Database (Denmark)

Haugland, Dag; Ho, Sin C.

Hunsaker and Savelsbergh have proposed an algorithm for testing feasibility of a route in the solution to the dial-a-ride problem. The constraints that are checked are load capacity constraints, time windows, ride time bounds and wait time bounds. The algorithm has linear running time. By virtue...

Feasibility Testing for Dial-a-Ride Problems

DEFF Research Database (Denmark)

Haugland, Dag; Ho, Sin C.

2010-01-01

Hunsaker and Savelsbergh have proposed an algorithm for testing feasibility of a route in the solution to the dial-a-ride problem. The constraints that are checked are load capacity constraints, time windows, ride time bounds and wait time bounds. The algorithm has linear running time. By virtue...

Modelling of a mecanum wheel taking into account the geometry of road rollers

Science.gov (United States)

Hryniewicz, P.; Gwiazda, A.; Banaś, W.; Sękala, A.; Foit, K.

2017-08-01

During the process planning in a company one of the basic factors associated with the production costs is the operation time for particular technological jobs. The operation time consists of time units associated with the machining tasks of a workpiece as well as the time associated with loading and unloading and the transport operations of this workpiece between machining stands. Full automation of manufacturing in industry companies tends to a maximal reduction in machine downtimes, thereby the fixed costs simultaneously decreasing. The new construction of wheeled vehicles, using Mecanum wheels, reduces the transport time of materials and workpieces between machining stands. These vehicles have the ability to simultaneously move in two axes and thus more rapid positioning of the vehicle relative to the machining stand. The Mecanum wheel construction implies placing, around the wheel free rollers that are mounted at an angle 450, which allow the movement of the vehicle not only in its axis but also perpendicular thereto. The improper selection of the rollers can cause unwanted vertical movement of the vehicle, which may cause difficulty in positioning of the vehicle in relation to the machining stand and the need for stabilisation. Hence the proper design of the free rollers is essential in designing the whole Mecanum wheel construction. It allows avoiding the disadvantageous and unwanted vertical vibrations of a whole vehicle with these wheels. In the article the process of modelling the free rollers, in order to obtain the desired shape of unchanging, horizontal trajectory of the vehicle is presented. This shape depends on the desired diameter of the whole Mecanum wheel, together with the road rollers, and the width of the drive wheel. Another factor related with the curvature of the trajectory shape is the length of the road roller and its diameter decreases depending on the position with respect to its centre. The additional factor, limiting construction of

Case histories of roller cone core bit application in crystalline rock

International Nuclear Information System (INIS)

Dahlem, J.S.

1988-01-01

The increased interest in deep crystalline rock drilling projects has resulted in a requirement for premium coring bits which are effective in such a harsh and abrasive environment. Hard formation roller cone insert bits have traditionally and constantly performed well in crystalline rock. As a result, the application of state of the art roller cone rock bit technology to the design and development of core bits has made crystalline coring projects more viable than ever before. This paper follows the development of roller cone core bits by examining their use on project such as HDR (Hot Dry Rock, Los Alamos); NAGRA (Nuclear Waste Disposal Wells in Switzerland); Camborne School of Mines Geothermal Project in Cornwall, UK; Deep Gas Project in Sweden; and the KTB Deep Drilling Project in West Germany

Spine fractures caused by horse riding

OpenAIRE

Siebenga, Jan; Segers, Michiel J. M.; Elzinga, Matthijs J.; Bakker, Fred C.; Haarman, Henk J. T. M.; Patka, Peter

2006-01-01

Study Design: Retrospective study and review of literature. Objectives: Study of demographic data concerning spinal fractures caused by horse riding, classification of fractures according to the AO and Load Sharing classifications, evaluation of mid-term radiological results and long-term functional results. Methods: A review of medical reports and radiological examinations of patients presented to our hospital with horse riding-related spine fractures over a 13-year period; long-term functio...

3000-HP Roller Gear Transmission Development Program. Volume 3. Roller Gear Manufacture

Science.gov (United States)

1975-07-01

power is fed through the ramp roller clutch type free- wheel units to spur gears which mesh with the combining spur gear whose centerline is common...when the engine tends to turn faster than the main rotor shaft. It is in the free- wheel mode when the main rotor shaft tends to turn faster than the...gears are cut progrind at this time. Check face runout on each end of largo gears. Not to exceed .002" TIR 30 EBW one end 40 EBW opposite end

Temperature and Thermal Expansion Analysis of the Cooling Roller Based on the Variable Heat Flux Boundary Condition

Science.gov (United States)

Li, Yongkang; Yang, Yang; He, Changyan

2018-06-01

Planar flow casting (PFC) is a primary method for preparing an amorphous ribbon. The qualities of the amorphous ribbon are significantly influenced by the temperature and thermal expansion of the cooling roller. This study proposes a new approach to analyze the three-dimensional temperature and thermal expansion of the cooling roller using variable heat flux that acted on the cooling roller as a boundary condition. First, a simplified two-dimensional model of the PFC is developed to simulate the distribution of the heat flux in the circumferential direction with the software FLUENT. The resulting heat flux is extended to be three-dimensional in the ribbon's width direction. Then, the extended heat flux is imported as the boundary condition by the CFX Expression Language, and the transient temperature of the cooling roller is analyzed in the CFX software. Next, the transient thermal expansion of the cooling roller is simulated through the thermal-structural coupling method. Simulation results show that the roller's temperature and expansion are unevenly distributed, reach the peak value in the middle width direction, and the quasi-steady state of the maximum temperature and thermal expansion are achieved after approximately 50 s and 150 s of casting, respectively. The minimum values of the temperature and expansion are achieved when the roller has a thickness of 45 mm. Finally, the reliability of the approach proposed is verified by measuring the roller's thermal expansion on the spot. This study provides theoretical guidance for the roller's thermal expansion prediction and the gap adjustment in the PFC.

Modelling and simulation of dynamic wheel-rail interaction using a roller rig

International Nuclear Information System (INIS)

Anyakwo, A; Pislaru, C; Ball, A; Gu, F

2012-01-01

The interaction between the wheel and rail greatly influences the dynamic response of railway vehicles on the track. A roller rig facility can be used to study and monitor real time parameters that influence wheel-rail interaction such as wear, adhesion, friction and corrugation without actual field tests being carried out. This paper presents the development of the mathematical models for full scale roller rig and 1/5 scale roller rig and the wear prediction model based on KTH wear function. The simulated critical speed for the 1/5 scale roller rig is about one-fifth of the critical speed for the full scale model so the simulated results compare well with the theory related to wheel-rail contact and dynamics. Also the differences between the simulated rolling radii for the full scale model with and without wear function are analysed. This paper presents the initial stage of a large scale research project where the influence of wear on the wheel-rail performance will be studied in more depth.

ANALYSIS OF MOVEMENT RESISTANCE OF CONVEYOR BELT AND ROLLERS IN THE COAL MINE MYSŁOWICE-WESOŁA

Directory of Open Access Journals (Sweden)

Tadeusz OPASIAK

2014-03-01

Full Text Available The paper presents a study of new design of SAG rollers. The study focused on the measurement of static and dynamic resistance of rotating rollers and the impact of new construction on the power consumption of the conveyor. Rollers have been modified through the use of class C4 bearing seals and labyrinth seal U4Exp 62/65 with a cover 2LU4 of runner construction. Measurements of static and dynamic resistance of rotating rollers were made on a universal rollers test bench, and power measurements were carried out on a belt conveyor power supply system Gwarek 1200 No. TW in KWK Mysłowice-Wesoła

Braking Control for Improving Ride Comfort

Directory of Open Access Journals (Sweden)

Lee Jonghyup

2018-01-01

Full Text Available While many vehicle control systems focus on vehicle safety and vehicle performance at high speeds, most driving conditions are very low risk situations. In such a driving situation, the ride comfort of the vehicle is the most important performance index of the vehicle. Electro mechanical brake (EMB and other brake-by-wire (BBW systems have been actively researched. As a result, braking actuators in vehicles are more freely controllable, and research on improving ride comfort is also possible. In this study, we develop a control algorithm that dramatically improves ride comfort in low risk braking situations. A method for minimizing the inconvenience of a passenger due to a suddenly changing acceleration at the moment when the vehicle is stopped is presented. For this purpose, an acceleration trajectory is generated that minimizes the discomfort index defined by the change in acceleration, jerk. A controller is also designed to track this trajectory. The algorithm that updates the trajectory is designed considering the error due to the phase lag occurring in the controller and the plant. In order to verify the performance of this controller, simulation verification is completed using a car simulator, Carsim. As a result, it is confirmed that the ride comfort is dramatically improved.

Minimum Makespan Multi-Vehicle Dial-a-Ride

DEFF Research Database (Denmark)

Gørtz, Inge Li; Nagarajan, Viswanath; Ravi, R.

2015-01-01

of multi-vehicle Dial-a-Ride, in which an object may be left at intermediate vertices and transported by more than one vehicle, while being moved from source to destination. Our main results are an O(log(3) n)-approximation algorithm for preemptive multi-vehicle Dial-a-Ride, and an improved O(log t...

Cost of a roller skating rink to the local accident and emergency department.

Science.gov (United States)

Nayeem, N; Shires, S E; Porter, J E

1990-01-01

A 14 month retrospective study was undertaken to determine the cost implications of the opening of a roller skating rink to the local hospital accident and emergency department (A and E). A total of 398 patients attended following injury at the roller skating rink, of whom 384 were included in the study. The estimated cost of their injuries was determined by the hospital accounts department. The average cost per patient attending the A and E department following roller skating injury was about 100 pounds. The total cost to the A and E department of all injuries sustained at the rink over this period was 38,412 pounds. The cost implications of opening a roller skating rink for the A and E department are considerable. If proposals for self-budgeting are applied, A and E departments will have to seek additional funding if such leisure facilities are opened in their vicinity. PMID:2097020

Influence of Surface-profile and Movement-path of Roller on Thickness Thinning during Multi-pass Deep Drawing Spinning

Directory of Open Access Journals (Sweden)

Xia Qinxiang

2016-01-01

Full Text Available Over thinning is a serious defect influencing the forming quality of spun workpiece during multi-pass deep drawing spinning. Surface-profile and movement-path of roller are the key factors influencing the thinning ratio of wall thickness of spun workpiece. The influence of surface-profile and movement-path of roller on thickness thinning were studied based on numerical simulation and experimental research, four groups of forming experiments were carried out under the combination of the different surface-profile of roller (R12 and R25-12 and movement-path of roller (spinning from the bottom of the blank and spinning from the middle of the blank. The results show that both the surface-profile and movement-path of roller have great influence on wall thickness thinning during multi-pass deep drawing spinning; and compared with the movement-path of roller, the influence of surface-profile of roller is more significant. The experimental results conform well to the simulation ones. It indicates that the FEA model established is reasonable and reliable.

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, for Calendar Year 2012

Energy Technology Data Exchange (ETDEWEB)

NSTec Environmental Restoration

2013-01-28

This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Units (CAUs) located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2012 and includes inspection and repair activities completed at the following CAUs: · CAU 400: Bomblet Pit and Five Points Landfill (TTR) · CAU 407: Roller Coaster RadSafe Area (TTR) · CAU 424: Area 3 Landfill Complexes (TTR) · CAU 453: Area 9 UXO Landfill (TTR) · CAU 487: Thunderwell Site (TTR)

Oriented Onion Sowing by a Forked-Roller Sowing Unit

Directory of Open Access Journals (Sweden)

Aleksandr G.

2018-03-01

Full Text Available Introduction: The existing sowing machines do not provide a single feeding of the bulbs with a planting (sowing unit that leads to a violation of the agrotechnical requirements of planting bulbs. It is necessary to search new solutions to preserve the position of the bulbs in the furrow with the bottom down and their regularly spaced distribution. Materials and Methods: The article presents the design for a prototype for a planting machine equipped with a forked-roller sowing unit for orienting the onion-sowing into a furrow. Testing the forked-roller sowing unit were carried out on a flat area where the physical and mechanical properties of the soil were determined on the days of sowing, and the indices of the quality of the onion-sowing were determined. The study of the effect of the sowing machine speed on the quality of the onion-seed bulb landing was determined by the change in the translational speed of the sowing unit in the range of 0.8 m/s to 1.2 m/s with a variation interval of 0.1 m/s. The indicators of the quality of the planting of the bulbs were determined by the opening of the closed furrow. The results of laboratory-field studies of the planting machine prototype are presented. Results: The results of laboratory-field studies of a planting machine equipped with a forked-roller sowing unit for planting onion bulbs are presented. The optimal technological parameters are determined experimentally. It was determined the number of bulbs that are for up is 51 % and the regularity of planting by the forked-roller sowing unit – 79 %. These figures are provided at the forward speed of the planting machine VM = 0.9–1.0 m/s, the height of the fall of the bulb HA = 0.12 m, and the rotation frequency of the landing drum nБ = 0.47 c-1. Discussion and Conclusions: The use of a forked-roller sowing unit makes it possible to increase the proportion of onions planted by bottom down by 200 %, and the uniformity of planting bulbs by 19 %, in

Improvement of Roller Bearing Diagnosis with Unlabeled Data Using Cut Edge Weight Confidence Based Tritraining

Directory of Open Access Journals (Sweden)

Wei-Li Qin

2016-01-01

Full Text Available Roller bearings are one of the most commonly used components in rotational machines. The fault diagnosis of roller bearings thus plays an important role in ensuring the safe functioning of the mechanical systems. However, in most cases of bearing fault diagnosis, there are limited number of labeled data to achieve a proper fault diagnosis. Therefore, exploiting unlabeled data plus few labeled data, this paper proposed a roller bearing fault diagnosis method based on tritraining to improve roller bearing diagnosis performance. To overcome the noise brought by wrong labeling into the classifiers training process, the cut edge weight confidence is introduced into the diagnosis framework. Besides a small trick called suspect principle is adopted to avoid overfitting problem. The proposed method is validated in two independent roller bearing fault experiment vibrational signals that both include three types of faults: inner-ring fault, outer-ring fault, and rolling element fault. The results demonstrate the desirable diagnostic performance improvement by the proposed method in the extreme situation where there is only limited number of labeled data.

PERANCANGAN PURWARUPA KOMIK INTERAKTIF SAFETY RIDING BERKONSEP DIGITAL STORYTELLING

Directory of Open Access Journals (Sweden)

Godham Eko Saputro

2016-12-01

Full Text Available Abstrak Di Indonesia khususnya kota besar, kecelakaan yang disebabkan kendaraan bermotor menjadi persoalan yang serius. Salah satunya disebabkan kurangnya pemahaman tentang safety riding. Berbagai upaya kampanye safety riding pun telah dilaksanakan oleh polisi lalu lintas melalui talkshow, siaran radio, serta media leaflet bagi masyarakat yang dilakukan berulang-ulang. Hal itu mendorong peneliti dalam upaya menemukan strategi baru, salah satunya memanfaatkan perkembangan teknologi yang sangat pesat guna mengembangkan media pendukung kampanye safety riding yang tidak hanya dapat menyampaikan pesan, tetapi juga disukai dan bersifat menghibur. Data diperoleh melalui wawancara, observasi, serta studi literatur sebagai sumber konten purwarupa komik interaktif. Melalui pendekatan digital storytelling dan model komunikasi SMCR serta mengacu pada Penelitian Pengembangan, konsep purwarupa komik interaktif bisa dijabarkan lebih detail serta dapat diimplementasikan dalam perangkat mobile khususnya tablet PC. Diharapkan purwarupa ini dapat dikembangkan lebih lanjut sehingga benar-benar dapat dipublish secara umum sebagai media pendukung kampanye safety riding. Kata Kunci: komik, interaktif, safety riding, digital storytelling Abstract In Indonesia especially in big cities, the accident which caused by rider is still become serious issue. One factor which cause accident is the lack of knowledge about safety riding. A lot of efforts which have been carried by traffic policeman are talkshow, radio broadcast, and leaflet media for public society. On the other hand, it courage the researchers in effort to find new startegy, one of them is using the advance of technology to develop another media campaign which not only can deliver the messages, but also can entertain user. This research is an effort to find unconventional media for safety riding campaign. Data was obtained through interview, observation, and study of literature as sources of content for

Verkkokaupan kansainvälistäminen Facebook-mainonnalla : Case HighRoller

OpenAIRE

Heikkinen, Tiia

2016-01-01

Verkkokauppa toimii HighRoller Suomi Oy:n HighRoller-lihashuoltolaiteen pääasiallisena myyntikanavana ja Facebook-markkinointikanavana. Tähän mennessä tuotetta on markkinoitu Facebookissa ilman varsinaista strategiaa. Nyt tuotetta viedään Ruotsiin ja uusia markkinoita varten suunniteltiin ja toteutettiin Facebook-mainoskampanja. Teoreettisessä viitekehyksessä käydään läpi aluksi digimarkkinointia, minkä jälkeen pohditaan sosiaalisen median merkitystä verkkokaupalle. Seuraavaksi keskitytää...

Aerodynamics in the amusement park: interpreting sensor data for acceleration and rotation

Science.gov (United States)

Löfstrand, Marcus; Pendrill, Ann-Marie

2016-09-01

The sky roller ride depends on interaction with the air to create a rolling motion. In this paper, we analyse forces, torque and angular velocities during different parts of the ride, combining a theoretical analysis, with photos, videos as well as with accelerometer and gyroscopic data, that may be collected e.g. with a smartphone. For interpreting the result, it must be taken into account that the sensors and their coordinate system rotate together with the rider. The sky roller offers many examples for physics education, from simple circular motion, to acceleration and rotation involving several axes, as well as the relation between wing orientation, torque and angular velocities and using barometer pressure to determine the elevation gain.

An investigation into the impact of magnesium stearate on powder feeding during roller compaction.

Science.gov (United States)

Dawes, Jason; Gamble, John F; Greenwood, Richard; Robbins, Phil; Tobyn, Mike

2012-01-01

A systematic evaluation on the effect of magnesium stearate on the transmission of a placebo formulation from the hopper to the rolls during screw fed roller compaction has been carried out. It is demonstrated that, for a system with two 'knurled' rollers, addition of 0.5% w/w magnesium stearate can lead to a significant increase in ribbon mass throughput, with a consequential increase in roll gap, compared to an unlubricated formulation (manufactured at equivalent process conditions). However, this effect is reduced if one of the rollers is smooth. Roller compaction of a lubricated formulation using two smooth rollers was found to be ineffective due to a reduction in friction at the powder/roll interface, i.e. powder was not drawn through the rollers leading to a blockage in the feeding system. An increase in ribbon mass throughput could also be achieved if the equipment surfaces were pre-lubricated. However this increase was found to be temporary suggesting that the residual magnesium stearate layer was removed from the equipment surfaces. Powder sticking to the equipment surfaces, which is common during pharmaceutical manufacturing, was prevented if magnesium stearate was present either in the blend, or at the roll surface. It is further demonstrated that the influence of the hopper stirrer, which is primarily used to prevent bridge formation in the hopper and help draw powder more evenly into the auger chamber, can lead to further mixing of the formulation, and could therefore affect a change in the lubricity of the carefully blended input material.

Design rules for out-of-plane stability of roller bent steel arches with FEM

NARCIS (Netherlands)

Spoorenberg, R.C.; Snijder, H.H.; Hoenderkamp, J.C.D.; Beg, D.

2012-01-01

This paper describes a numerical investigation into the out-of-plane buckling behavior of freestanding roller bent steel arches. As roller bent arches have structural imperfections which differ considerably from those of hot-rolled or welded sections, specific attention is paid to their inclusion in

Investigation on Motorcyclist Riding Behaviour at Curve Entry Using Instrumented Motorcycle

Science.gov (United States)

Yuen, Choon Wah; Karim, Mohamed Rehan; Saifizul, Ahmad

2014-01-01

This paper details the study on the changes in riding behaviour, such as changes in speed as well as the brake force and throttle force applied, when motorcyclists ride over a curve section road using an instrumented motorcycle. In this study, an instrumented motorcycle equipped with various types of sensors, on-board cameras, and data loggers, was developed in order to collect the riding data on the study site. Results from the statistical analysis showed that riding characteristics, such as changes in speed, brake force, and throttle force applied, are influenced by the distance from the curve entry, riding experience, and travel mileage of the riders. A structural equation modeling was used to study the impact of these variables on the change of riding behaviour in curve entry section. Four regression equations are formed to study the relationship between four dependent variables, which are speed, throttle force, front brake force, and rear brake force applied with the independent variables. PMID:24523660

Application research of ferrous matrix composites in roller ring used in high-speed wire/bar rolling mill

International Nuclear Information System (INIS)

Song Yanpei; Li Xiuqing; Bi Shuangxu

2010-01-01

Research highlights: → A composite structure roller rings was fabricated by centrifugal casting. → The roller rings consisted of outer WCP/Fe-C composites layer and inner Fe-C alloy matrix. → Hardness attained to HRA80-85 in the composites layer, and HRA73-76 in inner Fe-C alloy matrix where the toughness was over 8 J/cm 2 . → The wear resistance of the roller rings excelled that of high-speed steel, and approached to that of the WC hard alloy roll. → The production cost of the WCP/Fe-C composites roller ring decreased by 50%. - Abstract: Tungsten carbide particle (WC P ) reinforced ferrous matrix composites roller rings were fabricated by centrifugal casting. The microstructures, properties and application effect of the composites roller rings were investigated by SEM, TEM and various property testers. The experimental results show that the WC P were uniformly distributed in outer reinforced-layer (working-layer) of 20-50 mm in thickness and their volume fraction reached 60-80 vol.%; there was a good interface bonding between WC P and Fe-C alloy without any reaction products; hardness attained to HRA80-85 in working-layer, and HRA73-76 in inner ferrous matrix where the toughness was over 8 J/cm 2 ; the wear resistance of the composites roller rings excels that of high-speed steel; service life of the composites parts approached to that of the WC hard alloy roll when the same WC P -volume-fraction in working-layer were obtained for both of them, but the production cost of the WC P /Fe-C composites roller ring decreased by 50%.

Healthy Ride Trip Data

Data.gov (United States)

Allegheny County / City of Pittsburgh / Western PA Regional Data Center — A dataset that shows trips taken using the Healthy Ride system by quarter. The dataset includes bike number, membership type, trip start and end timestamp, and...

Simple and Versatile Dynamic Model of Spherical Roller Bearing

Directory of Open Access Journals (Sweden)

Behnam Ghalamchi

2013-01-01

Full Text Available Rolling element bearings are essential components of rotating machinery. The spherical roller bearing (SRB is one variant witnessing increasing use because it is self-aligning and can support high loads. It is becoming increasingly important to understand how the SRB responds dynamically under a variety of conditions. This study introduces a computationally efficient, three-degree-of-freedom, SRB model that was developed to predict the transient dynamic behaviors of a rotor-SRB system. In the model, bearing forces and deflections were calculated as a function of contact deformation and bearing geometry parameters according to the nonlinear Hertzian contact theory. The results reveal how some of the more important parameters, such as diametral clearance, the number of rollers, and osculation number, influence ultimate bearing performance. One pair of calculations looked at bearing displacement with respect to time for two separate arrangements of the caged side-by-side roller arrays, when they are aligned and when they are staggered. As theory suggests, significantly lower displacement variations were predicted for the staggered arrangement. Following model verification, a numerical simulation was carried out successfully for a full rotor-bearing system to demonstrate the application of this newly developed SRB model in a typical real world analysis.

Roller pressure algometry as a new tool for assessing dynamic pressure sensitivity in migraine

DEFF Research Database (Denmark)

Guerrero-Peral, Ángel L.; Ruíz, Marina; Barón, Johanna

2018-01-01

from 500 to 5300 g. Each roller was moved at a speed of 0.5 cm/sec over a 60 mm horizontal line covering the temporalis muscle. The dynamic pain threshold (the pressure level of the first painful roller) and pain elicited during the pain threshold (roller evoked pain) were determined. Static pressure...... pain thresholds were assessed over the temporalis muscle, C5/C6 joint, second metacarpal, and tibialis anterior. Results Side-to-side consistency between dynamic pain threshold (rs = 0.769, p ... was slightly stronger in chronic migraine. Pain during dynamic pain threshold was negatively associated with widespread pressure pain thresholds (-0.336 

ReRide: Performing Lower Back Rehabilitation While Riding Your Motorbike in Traffic

DEFF Research Database (Denmark)

Bagalkot, Naveen; Sokoler, Tomas; Baadkar, Suraj

2016-01-01

controlled mechanically moving display mounted on top of the bike's speedometer that alters the visibility of the speedometer to the rider indicating the correctness of back posture. Informed by embodied perception, the ReRide design emphasizes a rapid coupling between adjusting your back posture...

Effect of Using Porcelanite as Partial Replacement of Fine Aggregate on Roller Compacted Concrete with Different Curing Methods

Directory of Open Access Journals (Sweden)

Abeer Abdulqader Salih

2016-09-01

Full Text Available Roller-Compacted Concrete is a no-slump concrete, with no reinforcing steel, no forms, no finishing and wet enough to support compaction by vibratory rollers. Due to the effect of curing on properties and durability of concrete, the main purpose of this research is to study the effect of various curing methods (air curing, 7 days water curing, and permanent water curing and porcelanite (local material used as an Internal Curing agent with different replacement percentages of fine aggregate (volumetric replacement on some properties of Roller-Compacted Concrete and to explore the possibility of introducing practical Roller-Compacted Concrete for road pavement with minimum requirement of curing. Specimens were sawed from slabs of (380*380*100 mm for determination of Ultrasonic Pulse Velocity (UPV and Voids volume. Results show that using (5 % porcelanite improved the results of UPV and Voids volume of Roller-Compacted Concrete (with air curing as compared with reference Roller-Compacted Concrete (with permanent water curing by percentages ranging from(3.6 to 28.9% and (-8 to -15.5% respectively.

Never Riding the Tide

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 10. Never Riding the Tide - Seymour Benzer–The Founder of Neurogenetics. K VijayRaghavan Veronica Rodrigues. General Article Volume 13 Issue 10 October 2008 pp 909-915 ...

Examination of a University-Affiliated Safe Ride Program

Science.gov (United States)

Gieck, D. Joseph; Slagle, David M.

2010-01-01

A university-affiliated safe ride program was evaluated to determine whether these programs can reduce drunk-driving related costs. Data was collected from 187 safe ride passengers during three nights of operation. Among the passengers, 93% were enrolled at a local University, 31% were younger than 21, and 40% reported a prior alcohol-related…

General Case in Determining Center-To-Center Spacing Between the Screw and the Roller in a Roller Drive, and Initial Contact Point of Their Mating Thread Turns. Development of Calculation Method and Software

Directory of Open Access Journals (Sweden)

D. S. Blinov

2017-01-01

Full Text Available One of the most important trends in development of machine engineering is to improve load capacity of mechanisms, assemblies and parts without increasing their overall dimensions and weight. This is also relevant to the most promising items so far, i.e. orbital roller drives (ORD, which are the rotational-to-progressive motion converters widely used in vehicles. The previously published article suggested increasing a load capacity (by about 15% through reducing a thread turn section angle of the threaded ORD components and change of the radius of roller thread turn section outline. Due to such ORD modification, a number of the most critical ORD parameters are to be changed thereby demanding further research. Further, the article published suggests a method considering the abovementioned changes to calculate the dimensions of ORD main components and their tolerance ranges.Though this method being not complete as the increment of ORD center-to-center spacing in relation to its rated value, required for assembly, is unknown; and to determine the ORD center-to-center spacing increment, outer diameters of the roller and screw threads are to be known. Hence, these two methods are interconnected.This article presents the numerical calculation method, mathematical support and method to determine the increment of ORD center-to-center spacing and initial contact point of the mating roller and screw thread turns. Due to considerable scope of calculations, the method was turned into the software.Similar calculation methods and techniques were developed to a particular case, where the thread turn section angle of the threaded components was of 90°, and the roller thread turn section outline was a circular arc centered to the roller axis. Hence the developed numerical calculation method, mathematical support and technique refer to the general case which is to determine the ORD center-to-center spacing increment and initial contact point of the mating roller

Biomechanical pole and leg characteristics during uphill diagonal roller skiing.

Science.gov (United States)

Lindinger, Stefan Josef; Göpfert, Caroline; Stöggl, Thomas; Müller, Erich; Holmberg, Hans-Christer

2009-11-01

Diagonal skiing as a major classical technique has hardly been investigated over the last two decades, although technique and racing velocities have developed substantially. The aims of the present study were to 1) analyse pole and leg kinetics and kinematics during submaximal uphill diagonal roller skiing and 2) identify biomechanical factors related to performance. Twelve elite skiers performed a time to exhaustion (performance) test on a treadmill. Joint kinematics and pole/plantar forces were recorded separately during diagonal roller skiing (9 degrees; 11 km/h). Performance was correlated to cycle length (r = 0.77; P Push-off demonstrated performance correlations for impulse of leg force (r = 0.84), relative duration (r= -0.76) and knee flexion (r = 0.73) and extension ROM (r = 0.74). Relative time to peak pole force was associated with performance (r = 0.73). In summary, diagonal roller skiing performance was linked to 1) longer cycle length, 2) greater impulse of force during a shorter push-off with larger flexion/extension ROMs in leg joints, 3) longer leg swing, and 4) later peak pole force, demonstrating the major key characteristics to be emphasised in training.

Kinematics and Path Following Control of an Articulated Drum Roller

Science.gov (United States)

BIAN, Yongming; YANG, Meng; FANG, Xiaojun; WANG, Xiahui

2017-07-01

Automatic navigation of an articulated drum roller, which is an articulated steering type vehicle widely used in the construction industry, is highly expected for operation cost reduction and improvement of work efficiency. In order to achieve the path following control, considering that its steering system is articulated steering and two frames are articulated by an active revolute joint, a kinematic model and an error dynamic state-space equation of an articulated drum roller are proposed. Besides, a state-feedback control law based on Lyapunov stability theory is also designed, which can be proved to achieve the purpose of control by the analysis of stability. What's more, to evaluate the performance of the proposed method, simulation under the MATLAB/Simulink and experiments using positioning algorithm and errors correction at the uneven construction site are performed, with initial displacement error (-1.5 m), heading error (-0.11 rad) and steering angle (-0.19 rad). Finally, simulation and experimental results show that the errors and steering angle can decrease gradually, and converge to zero with time. Meanwhile, the control input is not saturated. An articulated drum roller can lock into a desired path with the proposed method in uneven fields.

77 FR 50716 - Tapered Roller Bearings From China

Science.gov (United States)

2012-08-22

... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-344 (Third Review)] Tapered Roller..., the United States International Trade Commission (Commission) determines, pursuant to section 751(c... notice in the Office of the Secretary, U.S. International Trade Commission, Washington, DC, and by...

A Roller Bearing Fault Diagnosis Method Based on LCD Energy Entropy and ACROA-SVM

Directory of Open Access Journals (Sweden)

HungLinh Ao

2014-01-01

Full Text Available This study investigates a novel method for roller bearing fault diagnosis based on local characteristic-scale decomposition (LCD energy entropy, together with a support vector machine designed using an Artificial Chemical Reaction Optimisation Algorithm, referred to as an ACROA-SVM. First, the original acceleration vibration signals are decomposed into intrinsic scale components (ISCs. Second, the concept of LCD energy entropy is introduced. Third, the energy features extracted from a number of ISCs that contain the most dominant fault information serve as input vectors for the support vector machine classifier. Finally, the ACROA-SVM classifier is proposed to recognize the faulty roller bearing pattern. The analysis of roller bearing signals with inner-race and outer-race faults shows that the diagnostic approach based on the ACROA-SVM and using LCD to extract the energy levels of the various frequency bands as features can identify roller bearing fault patterns accurately and effectively. The proposed method is superior to approaches based on Empirical Mode Decomposition method and requires less time.

Effect of amusement park rides on programmable shunt valve settings.

Science.gov (United States)

Strahle, Jennifer; Collins, Kelly; Stetler, William R; Smith, Brandon W; Garton, Thomas; Garton, Catherine; Garton, Hugh J L; Maher, Cormac O

2013-01-01

Magnetically programmable shunt valves are susceptible to environmental factors including magnetic fields and accelerative forces. It is unknown if rollercoasters with or without magnetic brakes or linear induction motors (LIMs) are capable of altering the setting of a programmable shunt valve. Two different valve types (type A, n = 10; type B, n = 9) were tested at varying resistance settings in 2 trials on 6 different amusement park rides including 2 rides with LIMs, 2 rides with magnetic brakes, and 2 rides without magnetic technology. The performance level of valve type A and the setting of valve type B changed on rollercoasters with magnets (A = 2.5% [2/80]; B = 5.6% [4/72]) and without magnets (A = 7.5% [3/40]; B = 2.8% [1/36]). Neither valve setting changed when exposed to a Ferris wheel or during ambulation throughout the park. Magnetically programmable valves are susceptible to changes in pressure settings when exposed to amusement park rides with elevated vertical gravitational forces, irrespective of the presence of LIMs or magnetic brakes. © 2013 S. Karger AG, Basel.

Simulation and Analysis of Roller Chain Drive Systems

DEFF Research Database (Denmark)

Pedersen, Sine Leergaard

The subject of this thesis is simulation and analysis of large roller chain drive systems, such as e.g. used in marine diesel engines. The aim of developing a chain drive simulation program is to analyse dynamic phenomena of chain drive systems and investigate different design changes to the syst......The subject of this thesis is simulation and analysis of large roller chain drive systems, such as e.g. used in marine diesel engines. The aim of developing a chain drive simulation program is to analyse dynamic phenomena of chain drive systems and investigate different design changes...... mathematical models, and compare to the prior done research. Even though the model is developed at first for the use of analysing chain drive systems in marine engines, the methods can with small changes be used in general, as for e.g. chain drives in industrial machines, car engines and motorbikes. A novel...

A method of increasing the depth of the plastically deformed layer in the roller burnishing process

Science.gov (United States)

Kowalik, Marek; Trzepiecinski, Tomasz

2018-05-01

The subject of this paper is an analysis of the determination of the depth of the plastically deformed layer in the process of roller burnishing a shaft using a newly developed method in which a braking moment is applied to the roller. It is possible to increase the depth of the plastically deformed layer by applying the braking moment to the roller during the burnishing process. The theoretical considerations presented are based on the Hertz-Bielayev and Huber-Mises theories and permit the calculation of the depth of plastic deformation of the top layer of the burnished shaft. The theoretical analysis has been verified experimentally and using numerical calculations based on the finite element method using the Msc.MARC program. Experimental tests were carried out on ring-shaped samples made of C45 carbon steel. The samples were burnished at different values of roller force and different values of braking moment. A significant increase was found in the depth of the plastically deformed surface layer of roller burnished shafts. Usage of the phenomenon of strain hardening of steel allows the technology presented here to increase the fatigue life of the shafts.

Assessment of solid microneedle rollers to enhance transmembrane delivery of doxycycline and inhibition of MMP activity.

Science.gov (United States)

Omolu, Abbie; Bailly, Maryse; Day, Richard M

2017-11-01

Many chronic wounds exhibit high matrix metalloproteinase (MMP) activity that impedes the normal wound healing process. Intradermal delivery (IDD) of sub-antimicrobial concentrations of doxycycline, as an MMP inhibitor, could target early stages of chronic wound development and inhibit further wound progression. To deliver doxycycline intradermally, the skin barrier must be disrupted. Microneedle rollers offer a minimally invasive technique to penetrate the skin by creating multiple microchannels that act as temporary conduits for drugs to diffuse through. In this study, an innovative and facile approach for delivery of doxycycline across Strat-M TM membrane was investigated using microneedle rollers. The quantity and rate of doxycycline diffusing through the micropores directly correlated with increasing microneedle lengths (250, 500 and 750 μm). Treatment of Strat-M TM with microneedle rollers resulted in a reduction in fibroblast-mediated collagen gel contraction and MMP activity compared with untreated Strat-M TM . Our results show that treatment of an epidermal mimetic with microneedle rollers provides sufficient permeabilization for doxycycline diffusion and inhibition of MMP activity. We conclude that microneedle rollers are a promising, clinically ready tool suitable for delivery of doxycycline intradermally to treat chronic wounds.

Roller-massager application to the quadriceps and knee-joint range of motion and neuromuscular efficiency during a lunge.

Science.gov (United States)

Bradbury-Squires, David J; Noftall, Jennifer C; Sullivan, Kathleen M; Behm, David G; Power, Kevin E; Button, Duane C

2015-02-01

Roller massagers are used as a recovery and rehabilitative tool to initiate muscle relaxation and improve range of motion (ROM) and muscular performance. However, research demonstrating such effects is lacking. To determine the effects of applying a roller massager for 20 and 60 seconds on knee-joint ROM and dynamic muscular performance. Randomized controlled clinical trial. University laboratory. Ten recreationally active men (age = 26.6 ± 5.2 years, height = 175.3 ± 4.3 cm, mass = 84.4 ± 8.8 kg). Participants performed 3 randomized experimental conditions separated by 24 to 48 hours. In condition 1 (5 repetitions of 20 seconds) and condition 2 (5 repetitions of 60 seconds), they applied a roller massager to the quadriceps muscles. Condition 3 served as a control condition in which participants sat quietly. Visual analog pain scale, electromyography (EMG) of the vastus lateralis (VL) and biceps femoris during roller massage and lunge, and knee-joint ROM. We found no differences in pain between the 20-second and 60-second roller-massager conditions. During 60 seconds of roller massage, pain was 13.5% (5.7 ± 0.70) and 20.6% (6.2 ± 0.70) greater at 40 seconds and 60 seconds, respectively, than at 20 seconds (P joint ROM was 10% and 16% greater in the 20-second and 60-second roller-massager conditions, respectively, than the control condition (P joint ROM and neuromuscular efficiency during a lunge.

Simulation of accelerated strip cooling on the hot rolling mill run-out roller table

International Nuclear Information System (INIS)

Muhin, U.; Belskij, S.; Makarov, E.; Koinov, T.

2013-01-01

Full text: A mathematical model of the thermal state of the metal on the run-out roller table of a continuous wide hot-strip mill is presented. The mathematical model takes into account the heat generation during the polymorphic γ → α transformation of super cooled austenite phase and the influence of chemical composition on the physical properties of the steel. The model allows the calculation of modes of accelerated cooling of strips on the run-out roller table of a continuous wide hot strip mill. Winding temperature calculation error does not exceed 20 °C for 98.5 % of the strips from low-carbon and low-alloyed steels. key words: hot rolled, wide-strip, accelerated cooling, run-out roller table, polymorphic transformation, mathematical modeling

Increasing the Energy Efficiency of the Cyclic Action Mechanisms in Rolling for a Roller Bed Used as an Example

Science.gov (United States)

andreev, A. N.; Kolesnichenko, D. A.

2017-12-01

The possibility of increasing the energy efficiency of the production cycle in a roller bed is briefly reviewed and justified. The sequence diagram of operation of the electrical drive in a roller bed is analyzed, and the possible increase in the energy efficiency is calculated. A method for energy saving is described for the application of a frequency-controlled asynchronous electrical drive of drive rollers in a roller bed with an increased capacitor capacity in a dc link. A fine mathematical model is developed to describe the behavior of the electrical drive during the deceleration of a roller bed. An experimental setup is created and computer simulation and physical modeling are performed. The basic information flows of the general hierarchical automatic control system of an enterprise are described and determined with allowance for the proposed method of increasing the energy efficiency.

Do Maximal Roller Skiing Speed and Double Poling Performance Predict Youth Cross-Country Skiing Performance?

Directory of Open Access Journals (Sweden)

Roland Stöggl, Erich Müller, Thomas Stöggl

2017-09-01

Full Text Available The aims of the current study were to analyze whether specific roller skiing tests and cycle length are determinants of youth cross-country (XC skiing performance, and to evaluate sex specific differences by applying non-invasive diagnostics. Forty-nine young XC skiers (33 boys; 13.8 ± 0.6 yrs and 16 girls; 13.4 ± 0.9 yrs performed roller skiing tests consisting of both shorter (50 m and longer durations (575 m. Test results were correlated with on snow XC skiing performance (PXC based on 3 skating and 3 classical distance competitions (3 to 6 km. The main findings of the current study were: 1 Anthropometrics and maturity status were related to boys’, but not to girls’ PXC; 2 Significant moderate to acceptable correlations between girls’ and boys’ short duration maximal roller skiing speed (double poling, V2 skating, leg skating and PXC were found; 3 Boys’ PXC was best predicted by double poling test performance on flat and uphill, while girls’ performance was mainly predicted by uphill double poling test performance; 4 When controlling for maturity offset, boys’ PXC was still highly associated with the roller skiing tests. The use of simple non-invasive roller skiing tests for determination of PXC represents practicable support for ski clubs, schools or skiing federations in the guidance and evaluation of young talent.

Mechanical analysis and optimisation of large and highly-loaded bearing rollers For the "Riesenrad" Ion Gantry

CERN Document Server

Reimoser, S A

2000-01-01

A carbon ion gantry would allow the irradiation of cancer patients with carbon ions from any direction in space best suited for therapy. Till today, such a machine has not been built due to the expected size, mass and cost. A novel design, called "Riesenrad" ion gantry, promises to provide a competitive solution. The central part of the Riesenrad, which can rotate ± 90°, is supported (statically determinate) on pendular bearing units with two rollers each. High precision requirements for the structure rule out any plastic deformations in the area of contact. The present report describes the design of the highly-loaded rollers. In order to achieve a large contact area and a uniform distribution of contact stresses, a "barrel shape" for the rollers is proposed. An analysis using the finite element method (FEM) was performed to optimise the roller design, namely to establish the required crown roll (camber radius).

FUNDING ALTERNATIVES FOR LOW-LEVEL WASTE DISPOSAL

International Nuclear Information System (INIS)

Becker, Bruce D.; Carilli, Jhon

2003-01-01

For 13 years, low-level waste (LLW) generator fees and disposal volumes for the U.S. Department of Energy (DOE) National Nuclear Security Administration Nevada Operations Office (NNSA/NV) Radioactive Waste Management Sites (RWMSs) had been on a veritable roller coaster ride. As forecast volumes and disposal volumes fluctuated wildly, generator fees were difficult to determine and implement. Fiscal Year (FY) 2000 forecast projections were so low, the very existence of disposal operations at the Nevada Test Site (NTS) were threatened. Providing the DOE Complex with a viable, cost-effective disposal option, while assuring the disposal site a stable source of funding, became the driving force behind the development of the Waste Generator Access Fee at the NTS. On September 26, 2000, NNSA/NV (after seeking input from DOE/Headquarters [HQ]), granted permission to Bechtel Nevada (BN) to implement the Access Fee for FY 2001 as a two-year Pilot Program. In FY 2001 (the first year the Access Fee was implemented), the NTS Disposal Operations experienced a 90 percent increase in waste receipts from the previous year and a 33 percent reduction in disposal fee charged to the waste generators. Waste receipts for FY 2002 were projected to be 63 percent higher than FY 2001 and 15 percent lower in cost. Forecast data for the outyears are just as promising. This paper describes the development, implementation, and ultimate success of this fee strategy

Vital signs : no end in sight to high revenues for producers (and headaches for consumers)

International Nuclear Information System (INIS)

Lunan, D.

2001-01-01

Prices for petroleum products in North America have been on a roller coaster ride for a while now, with prices remaining high for the normally more dormant summer season. Although it is beneficial to producers, consumers are not as happy about the situation. Refinery problems, growing demand and product proliferation have combined to create this situation. Refineries on the East Coast of the United States were forced to extend the required maintenance period in the spring since they had been running non-stop to meet the requirements of last winter. Canadian refiners benefited from the situation. They enjoy strong refining margins. Canadian refined-product exports jumped 22 per cent higher in February of 2001 when compared to February 2000. Heavy fuel oil exports in January and February were especially strong, as the industrial boilers in the United States were feeling the effects of the very high natural gas prices. A similar phenomenon was reflected in exports of gasoline and crude oil. The commissioning last year of the Alliance Pipeline and successful exploration programs in British Columbia ensured it led the pack. The crude production in Saskatchewan was up 11.4 per cent due to the widespread horizontal drilling and recovery programs. To ensure adequate winter peaking supplies, storage injections are lagging behind, which tends to indicate that gas prices will remain high for the remainder of the year. 7 tabs., 4 figs

Analytical evaluation of the roller bearing service life

Directory of Open Access Journals (Sweden)

Antsupov Aleksey

2017-01-01

Full Text Available An analytical method has been developed for the design evaluation of the service life of roller bearings by the criterion of contact endurance of elements that does not require carrying out the experimental studies. It is based on the kinetic approach to the description of the solids destruction process and the theory of parametric reliability of machine parts. In contradistinction to the standard empirical dependence, which is currently used, the method allows one to take into account the effect of the material properties, and basic design and operational parameters on the service life. The results of the theoretical studies of the service life of roller bearing No. 212 (DIN 5412 T1 are presented for the quantitative assessment of this effect. They showed that the temperature-force loading conditions or material properties that were not taken into account might result in the prediction error of 1.5 or more times.

Visualization and prediction of porosity in roller compacted ribbonswith near infrared chemical imaging (NIR-CI)

DEFF Research Database (Denmark)

Khorasani, Milad Rouhi; Amigo Rubio, Jose Manuel; Sonnergaard, Jørn

2015-01-01

The porosity of roller compacted ribbon is recognized as an important critical quality attribute which has a huge impact on the final product quality. The purpose of this study was to investigate the use of near-infrared chemical imaging (NIR-CI) for porosity estimation of ribbons produced...... and control of continuously operating roller compaction line....

Ride comfort analysis with physiological parameters for an e-health train.

Science.gov (United States)

Lee, Youngbum; Shin, Kwangsoo; Lee, Sangjoon; Song, Yongsoo; Han, Sungho; Lee, Myoungho

2009-12-01

Transportation by train has numerous advantages over road transportation, especially with regard to energy efficiency, ecological features, safety, and punctuality. However, the contrast in ride comfort between standard road transportation and train travel has become a competitive issue. The ride comfort enhancement technology of tilting trains (TTX) is a particularly important issue in the development of the Korean high-speed railroad business. Ride comfort is now defined in international standards such as UIC13 and ISO2631. The Korean standards such as KSR9216 mainly address physical parameters such as vibration and noise. In the area of ride comfort, living quality parameter techniques have recently been considered in Korea, Japan, and Europe. This study introduces biological parameters, particularly variations in heart rate, as a more direct measure of comfort. Biological parameters are based on physiological responses rather than on purely external mechanical parameters. Variability of heart rate and other physiological parameters of passengers are measured in a simulation involving changes in the tilting angle of the TTX. This research is a preliminary study for the implementation of an e-health train, which would provide passengers with optimized ride comfort. The e-health train would also provide feedback on altered ride comfort situations that can improve a passenger's experience and provide a healthcare service on the train. The aim of this research was to develop a ride comfort evaluation system for the railway industry, the automobile industry, and the air industry. The degree of tilt correlated with heart rate, fatigue, and unrelieved alertness.

Your Guide to Physical Activity and Your Heart

Science.gov (United States)

... flat ground) Horseback riding Roller skating/ice skating Softball Swimming Tennis (doubles) Walking moderately (3.5 mph) ... such as dancing; or group sports, such as softball or doubles tennis? If you like to be ...

Neuromuscular Responses of Elite Skaters During Different Roller Figure Skating Jumps

Directory of Open Access Journals (Sweden)

Pantoja Patrícia Dias

2014-07-01

Full Text Available This study aimed to describe the neuromuscular activity of elite athletes who performed various roller figure skating jumps, to determine whether the muscle activation is greater during jumps with more rotations and in which phase the muscles are more active. This study also aimed to analyze if there is any difference in the muscle activity pattern between female and male skaters. Four elite skaters were evaluated, and each participated in two experimental sessions. During the first session, anthropometric data were collected, and the consent forms were signed. For the second session, neuromuscular data were collected during jumps, which were performed with skates at a rink. The following four roller figure skating jumps were evaluated: single Axel, double Axel, double Mapes and triple Mapes. The neuromuscular activity of the following seven muscles was obtained with an electromyograph which was fixed to the waist of each skater with a strap: biceps femoris, lateral gastrocnemius, tibialis anterior, rectus femoris, vastus lateralis, vastus medialis and gluteus maximus. The signal was transmitted wirelessly to a laptop. During the roller figure skating jumps, the lateral gastrocnemius, rectus femoris, vastus lateralis, biceps femoris and gluteus maximus, showed more activation during the jumps with more rotations, and the activation mainly occurred during the propulsion and flight phases. Female skaters demonstrated higher muscle activities in tibialis anterior, vastus lateralis, vastus medialis and gluteus maximus during the landing phase of the triple Mapes, when compared to their male counterparts. The results obtained in this study should be considered when planning training programs with specific exercises that closely resemble the roller figure skating jumps. This may be important for the success of elite skaters in competitions.

Neuromuscular Responses of Elite Skaters During Different Roller Figure Skating Jumps

Science.gov (United States)

Pantoja, Patrícia Dias; Mello, André; Liedtke, Giane Veiga; Kanitz, Ana Carolina; Cadore, Eduardo Lusa; Pinto, Stephanie Santana; Alberton, Cristine Lima; Kruel, Luiz Fernando Martins

2014-01-01

This study aimed to describe the neuromuscular activity of elite athletes who performed various roller figure skating jumps, to determine whether the muscle activation is greater during jumps with more rotations and in which phase the muscles are more active. This study also aimed to analyze if there is any difference in the muscle activity pattern between female and male skaters. Four elite skaters were evaluated, and each participated in two experimental sessions. During the first session, anthropometric data were collected, and the consent forms were signed. For the second session, neuromuscular data were collected during jumps, which were performed with skates at a rink. The following four roller figure skating jumps were evaluated: single Axel, double Axel, double Mapes and triple Mapes. The neuromuscular activity of the following seven muscles was obtained with an electromyograph which was fixed to the waist of each skater with a strap: biceps femoris, lateral gastrocnemius, tibialis anterior, rectus femoris, vastus lateralis, vastus medialis and gluteus maximus. The signal was transmitted wirelessly to a laptop. During the roller figure skating jumps, the lateral gastrocnemius, rectus femoris, vastus lateralis, biceps femoris and gluteus maximus, showed more activation during the jumps with more rotations, and the activation mainly occurred during the propulsion and flight phases. Female skaters demonstrated higher muscle activities in tibialis anterior, vastus lateralis, vastus medialis and gluteus maximus during the landing phase of the triple Mapes, when compared to their male counterparts. The results obtained in this study should be considered when planning training programs with specific exercises that closely resemble the roller figure skating jumps. This may be important for the success of elite skaters in competitions. PMID:25114728

Modeling of Comparative Performance of Asphalt Concrete under Hammer, Gyratory, and Roller Compaction

Directory of Open Access Journals (Sweden)

Saad I. Sarsam

2016-11-01

Full Text Available The main objective of this study is to develop predictive models using SPSS software (version 18 for Marshall Test results of asphalt mixtures compacted by Hammer, Gyratory, and Roller compaction. Bulk density of (2.351 gm/cc, at OAC of (4.7 % was obtained as a benchmark after using Marshall Compactor as laboratory compactive effort with 75-blows. Same density was achieved by Roller and Gyratory Compactors using its mix designed methods. A total of (75 specimens, for Marshall, Gyratory, and Roller Compactors have been prepared, based on OAC of (4.7 % with an additional asphalt contents of more and less than (0.5 % from the optimum value. All specimens have been subjected to Marshall Test. Mathematical models obtained indicated that variation of Marshall Stiffness is based on the variation of air voids. All of these models depend on asphalt cement content too.

DETERMINATION OF ADHESIVE STRENGTH LAYER’S ROLLER COMPACTED CONCRETE THE METHOD AXIAL EXTENSION

Directory of Open Access Journals (Sweden)

Tang Van Lam

2017-07-01

Full Text Available Roller compacted concrete for the construction of hydraulic and hydroelectric buildings is a composite material, which consists of a binder, fine aggregate (sand, coarse aggregate (gravel or crushed stone, water and special additives that provide the desired concrete workability and impart the required concrete performance properties. Concrete mixture is prepared at from concrete mixing plants strictly metered quantities of cement, water, additives and graded aggregates, whereupon they are delivered to the site laying Mixer Truck and sealing layers with each stack layer. The advantages of roller compaction technology should include the reduction of construction time, which allows fast commissioning construction projects, as well as reduce the amount of investment required. One of the main problems encountered in the process of roller compaction of the concrete mix is the need to provide the required adhesion strength between layers of concrete. This paper presents a method for determining the strength of adhesion between the concrete layers of different ages roller compacted concrete using axial tension. This method makes it possible to obtain objective and accurate results with a total thickness of layers of compacted concrete of up to 300…400 mm. Results from this method, studies have shown that the value of strength between the concrete layers in addition to the composition of the concrete and adhesion depends on the quality and the parallel end surfaces of the cylinder-models, which are mounted steel plates for axial tension, as well as the state of the contact surfaces of the concrete layer. The method can be used to determine the strength of interlayer adhesion in roller compacted concrete, which are used in the construction of dams and other hydraulic structures.

Effect of Silicon Nitride Balls and Rollers on Rolling Bearing Life

Science.gov (United States)

Zaretsky, Erwin V.; Vlcek, Brian L.; Hendricks, Robert C.

2005-01-01

Three decades have passed since the introduction of silicon nitride rollers and balls into conventional rolling-element bearings. For a given applied load, the contact (Hertz) stress in a hybrid bearing will be higher than an all-steel rolling-element bearing. The silicon nitride rolling-element life as well as the lives of the steel races were used to determine the resultant bearing life of both hybrid and all-steel bearings. Life factors were determined and reported for hybrid bearings. Under nominal operating speeds, the resultant calculated lives of the deep-groove, angular-contact, and cylindrical roller hybrid bearings with races made of post-1960 bearing steel increased by factors of 3.7, 3.2, and 5.5, respectively, from those calculated using the Lundberg-Palmgren equations. An all-steel bearing under the same load will have a longer life than the equivalent hybrid bearing under the same conditions. Under these conditions, hybrid bearings are predicted to have a lower fatigue life than all-steel bearings by 58 percent for deep-groove bearings, 41 percent for angular-contact bearings, and 28 percent for cylindrical roller bearings.

To Enhance the Fire Resistance Performance of High-Speed Steel Roller Door with Water Film System

Directory of Open Access Journals (Sweden)

De-Hua Chung

2015-01-01

Full Text Available The structure of high-speed roller door with water film has improved in this study. The flameproof water film system is equipped with a water circulating device to reduce the water consumption of water film system. The water film is generated at the roller box of the high-speed roller door in this study. The heating test is done with the full-scale heating furnace. Both cases of the water film on unexposed surface and water film on exposed surface passed the fire resistance test based on ISO 834, proving that the high-speed roller door with water film system has 120A fire resistance period. The main findings indicate that the water film on exposed surface shows that as the amount of water film evaporated by high temperature inside the furnace must be greater than the evaporation capacity of water film on unexposed surface, the required water supply is 660 L more than the water film on unexposed surface.

Analyzing Forces on Amusement Park Rides with Mobile Devices

Science.gov (United States)

Vieyra, Rebecca E.; Vieyra, Chrystian

2014-01-01

Mobile device accelerometers are a simple and easy way for students to collect accurate and detailed data on an amusement park ride. The resulting data can be graphed to assist in the creation of force diagrams to help students explain their physical sensations while on the ride. This type of activity can help students overcome some of the…

Influences of Carbody Vertical Flexibility on Ride Comfort of Railway Vehicles

Directory of Open Access Journals (Sweden)

Dumitriu Mădălina

2017-06-01

Full Text Available The article investigates the influence of the carbody vertical flexibility on the ride comfort of the railway vehicles. The ride comfort is evaluated via the comfort index calculated in three reference points of the carbody. The results of the numerical simulations bring attention to the importance of the carbody symmetrical vertical bending upon the dynamic response of the vehicle, mainly at high velocities. Another conclusion is that the ride comfort can be significantly affected as a function of the symmetrical bending frequency of the carbody. Similarly, there are improvement possibilities for the ride comfort when the best selection of the stiffness in the longitudinal traction system between the carbody and bogie and the vertical suspension damping is made.

Assesment on Reproductive Performance and Hormonal Studies in Rural Women Beedi Rollers in Jagitial District of Telangana State

Directory of Open Access Journals (Sweden)

Vanitha Baluka

2017-10-01

Full Text Available Beedi manufacturing is the second largest industry in India. It provides employment to millions of women mostly from the poor socioeconomic class. In North region of Telangana, beedi rolling is a major occupation for illiterate women in many villages. It may affect due to the inhalation of unfiltered tobacco dust and volatile and toxic components of tobacco. Biomonitoring of women beedi rollers and their reproductive performance assessment is necessary to take prevention/control the reproduction failure and carcinogen effect on cervical system. Continuous exposed to unfiltered tobacco dust may have systemic effect and lead to many disorders including hormone defects and reproductive health problems. Although studies have been carried out on beedi industry workers and tobacco smoke exposed people at national and international level, no such studies were carried out on women beedi rollers living in rural areas in Telangana State. Hence, this investigation is attempted to understand the study is find to association with hormonal levels and reproductive outcome in rural women beedi rollers of reproductive age in North Telangana. Statistical analysis was done for the obtained results to find the significance between the two groups for the reproductive outcome and Hormonal Studies. Total 50 women (married who are exposed minimum 6-10 years to the unfiltered tobacco dust beedi rollers in the age group of 25 to 45 years from villages of Jagitial district were enrolled for this study. 50 equal numbers of women in the same age group belonging to the same socio economic status and not exposed occupationally to chemical and physical agents was selected for comparison (control group. Estroidal, Progesterone the T3, T4 and TSH levels were measured found significantly T3, T4 levels were low in the beedi rollers, compared the controls. TSH levels were found to be higher in the beedi rollers. Estroidal and progesterone levels were obtained non

Supernetwork approach for modeling traveler response to park-and-ride

NARCIS (Netherlands)

Liao, F.; Arentze, T.A.; Timmermans, H.J.P.

2012-01-01

Park-and-ride has been identified by transport planners as a key element of any sustainability package to promote multimodal trips, improve air quality, and alleviate congestion in urban areas. This paper presents a supernetwork approach that can assess traveler response to park-and-ride in an

Compressed sensing of roller bearing fault based on multiple down-sampling strategy

Science.gov (United States)

Wang, Huaqing; Ke, Yanliang; Luo, Ganggang; Tang, Gang

2016-02-01

Roller bearings are essential components of rotating machinery and are often exposed to complex operating conditions, which can easily lead to their failures. Thus, to ensure normal production and the safety of machine operators, it is essential to detect the failures as soon as possible. However, it is a major challenge to maintain a balance between detection efficiency and big data acquisition given the limitations of sampling theory. To overcome these limitations, we try to preserve the information pertaining to roller bearing failures using a sampling rate far below the Nyquist sampling rate, which can ease the pressure generated by the large-scale data. The big data of a faulty roller bearing’s vibration signals is firstly reduced by a down-sample strategy while preserving the fault features by selecting peaks to represent the data segments in time domain. However, a problem arises in that the fault features may be weaker than before, since the noise may be mistaken for the peaks when the noise is stronger than the vibration signals, which makes the fault features unable to be extracted by commonly-used envelope analysis. Here we employ compressive sensing theory to overcome this problem, which can make a signal enhancement and reduce the sample sizes further. Moreover, it is capable of detecting fault features from a small number of samples based on orthogonal matching pursuit approach, which can overcome the shortcomings of the multiple down-sample algorithm. Experimental results validate the effectiveness of the proposed technique in detecting roller bearing faults.

Compressed sensing of roller bearing fault based on multiple down-sampling strategy

International Nuclear Information System (INIS)

Wang, Huaqing; Ke, Yanliang; Luo, Ganggang; Tang, Gang

2016-01-01

Roller bearings are essential components of rotating machinery and are often exposed to complex operating conditions, which can easily lead to their failures. Thus, to ensure normal production and the safety of machine operators, it is essential to detect the failures as soon as possible. However, it is a major challenge to maintain a balance between detection efficiency and big data acquisition given the limitations of sampling theory. To overcome these limitations, we try to preserve the information pertaining to roller bearing failures using a sampling rate far below the Nyquist sampling rate, which can ease the pressure generated by the large-scale data. The big data of a faulty roller bearing’s vibration signals is firstly reduced by a down-sample strategy while preserving the fault features by selecting peaks to represent the data segments in time domain. However, a problem arises in that the fault features may be weaker than before, since the noise may be mistaken for the peaks when the noise is stronger than the vibration signals, which makes the fault features unable to be extracted by commonly-used envelope analysis. Here we employ compressive sensing theory to overcome this problem, which can make a signal enhancement and reduce the sample sizes further. Moreover, it is capable of detecting fault features from a small number of samples based on orthogonal matching pursuit approach, which can overcome the shortcomings of the multiple down-sample algorithm. Experimental results validate the effectiveness of the proposed technique in detecting roller bearing faults. (paper)

A participatory sensing approach to characterize ride quality

Science.gov (United States)

Bridgelall, Raj

2014-03-01

Rough roads increase vehicle operation and road maintenance costs. Consequently, transportation agencies spend a significant portion of their budgets on ride-quality characterization to forecast maintenance needs. The ubiquity of smartphones and social media, and the emergence of a connected vehicle environment present lucrative opportunities for cost-reduction and continuous, network-wide, ride-quality characterization. However, there is a lack of models to transform inertial and position information from voluminous data flows into indices that transportation agencies currently use. This work expands on theories of the Road Impact Factor introduced in previous research. The index characterizes road roughness by aggregating connected vehicle data and reporting roughness in direct proportion to the International Roughness Index. Their theoretical relationships are developed, and a case study is presented to compare the relative data quality from an inertial profiler and a regular passenger vehicle. Results demonstrate that the approach is a viable alternative to existing models that require substantially more resources and provide less network coverage. One significant benefit of the participatory sensing approach is that transportation agencies can monitor all network facilities continuously to locate distress symptoms, such as frost heaves, that appear and disappear between ride assessment cycles. Another benefit of the approach is continuous monitoring of all high-risk intersections such as rail grade crossings to better understand the relationship between ride-quality and traffic safety.

Capability of DFIG WTS to ride through recurring asymmetrical grid faults

DEFF Research Database (Denmark)

Chen, Wenjie; Blaabjerg, Frede; Chen, Min

2014-01-01

The Wind Turbine Systems (WTS) are required to ride through recurring grid faults in some countries. In this paper, the capability of Doubly Fed Induction Generator (DFIG) WTS to ride through recurring asymmetrical grid faults is evaluated and compared with the ride through capability under single...... asymmetrical grid fault. A mathematical model of the DFIG under recurring asymmetrical grid faults is represented. The analysis are verified by simulations on a 1.5MW DFIG model and by experiments on a reduced-scale DFIG test system....

Pervasive liquid metal based direct writing electronics with roller-ball pen

Directory of Open Access Journals (Sweden)

Yi Zheng

2013-11-01

Full Text Available A roller-ball pen enabled direct writing electronics via room temperature liquid metal ink was proposed. With the rolling to print mechanism, the metallic inks were smoothly written on flexible polymer substrate to form conductive tracks and electronic devices. The contact angle analyzer and scanning electron microscope were implemented to disclose several unique inner properties of the obtained electronics. An ever high writing resolution with line width and thickness as 200 μm and 80 μm, respectively was realized. Further, with the administration of external writing pressure, GaIn24.5 droplets embody increasing wettability on polymer which demonstrates the pervasive adaptability of the roller-ball pen electronics.

Scaling Law of Urban Ride Sharing

Science.gov (United States)

Tachet, R.; Sagarra, O.; Santi, P.; Resta, G.; Szell, M.; Strogatz, S. H.; Ratti, C.

2017-03-01

Sharing rides could drastically improve the efficiency of car and taxi transportation. Unleashing such potential, however, requires understanding how urban parameters affect the fraction of individual trips that can be shared, a quantity that we call shareability. Using data on millions of taxi trips in New York City, San Francisco, Singapore, and Vienna, we compute the shareability curves for each city, and find that a natural rescaling collapses them onto a single, universal curve. We explain this scaling law theoretically with a simple model that predicts the potential for ride sharing in any city, using a few basic urban quantities and no adjustable parameters. Accurate extrapolations of this type will help planners, transportation companies, and society at large to shape a sustainable path for urban growth.

High-energy roller injuries to the upper extremity.

Science.gov (United States)

Askins, G; Finley, R; Parenti, J; Bush, D; Brotman, S

1986-12-01

Eleven cases of high-energy industrial roller injuries treated between 1980 and 1984 were retrospectively reviewed. The dominant extremity was affected in nine. Six patients sustained fractures and/or dislocations, and three of these patients required fasciotomies for clinical signs of impending compartment syndromes. All fracture/dislocations, with the exception of a scapula fracture, anterior dislocation of a thumb interphalangeal joint, and a fractured coronoid process of the ulna, required open reduction with internal fixation. Three patients required split-thickness skin grafting for extensive skin degloving. Two patients required immediate amputation. Late sequelae included prolonged edema, nutritional depletion, neuroma formation of the superficial branch of the radial nerve, late carpal tunnel syndrome, and partial brachial plexus palsy. Industrial roller injuries continue to be an occupational hazard associated with more severe crushing trauma than the low-energy wringer washer injuries first described by MacCollum (11). Attention must be paid to the treatment of crushed skin, muscle, and nerves, fracture stabilization, nutritional support, and occupational therapy. Concurrent monitoring for signs of a developing compartment syndrome and complications of rhabdomyolysis is essential.

Scale up of diesel oil biodegradation in a baffled roller bioreactor.

Science.gov (United States)

Nikakhtari, Hossein; Song, Wanning; Kumar, Pardeep; Nemati, Mehdi; Hill, Gordon A

2010-05-01

Diesel oil is a suitable substance to represent petroleum contamination from accidental spills in operating and transportation facilities. Using a microbial culture enriched from a petroleum contaminated soil, biodegradation of diesel oil was carried out in 2.2, 55, and 220 L roller baffled bioreactors. The effects of bioreactor rotation speed (from 5 to 45 rpm) and liquid loading (from 18% to 73% of total volume) on the biodegradation of diesel oil were studied. In the small scale bioreactor (2.2L), the maximum rotation speed of 45 rpm resulted in the highest biodegradation rate with a first order biodegradation kinetic constant of 0.095 d(-1). In the larger scale bioreactors, rotation speed did not affect the biodegradation rate. Liquid loadings higher than 64% resulted in reduced biodegradation rates in the small scale bioreactor; however, in the larger roller bioreactors liquid loading did not affect the biodegradation rate. Biodegradation of diesel oil at 5 rpm and 73% loading is recommended for operating large scale roller baffled bioreactors. Under these conditions, high diesel oil concentrations up to 50 gL(-1) can be bioremediated at a rate of 1.61 gL(-1)d(-1). Copyright 2010 Elsevier Ltd. All rights reserved.

The dynamic analysis of drum roll lathe for machining of rollers

Science.gov (United States)

Qiao, Zheng; Wu, Dongxu; Wang, Bo; Li, Guo; Wang, Huiming; Ding, Fei

2014-08-01

An ultra-precision machine tool for machining of the roller has been designed and assembled, and due to the obvious impact which dynamic characteristic of machine tool has on the quality of microstructures on the roller surface, the dynamic characteristic of the existing machine tool is analyzed in this paper, so is the influence of circumstance that a large scale and slender roller is fixed in the machine on dynamic characteristic of the machine tool. At first, finite element model of the machine tool is built and simplified, and based on that, the paper carries on with the finite element mode analysis and gets the natural frequency and shaking type of four steps of the machine tool. According to the above model analysis results, the weak stiffness systems of machine tool can be further improved and the reasonable bandwidth of control system of the machine tool can be designed. In the end, considering the shock which is caused by Z axis as a result of fast positioning frequently to feeding system and cutting tool, transient analysis is conducted by means of ANSYS analysis in this paper. Based on the results of transient analysis, the vibration regularity of key components of machine tool and its impact on cutting process are explored respectively.

Pensionäride probleemid jõuavad Euroopa Komisjoni / Arvo Einre ; interv. Asse Soomets

Index Scriptorium Estoniae

Einre, Arvo, 1931-2012

2005-01-01

Eesti Pensionäride Ühendus sai Euroopa Komisjoni eakate nõukojalt (The European Older People Platform) kutse 31. märtsil Brüsselis toimuvale AGE töökoosolekule, kus käsitletakse pensionäride olukorda EL-i liikmesriikides. Eesti esindajana sõidab üritusele Eesti Pensionäride Ühenduse aseesimees Arvo Einre

Fabrication of a roller type PDMS stamp using SU-8 concave molds and its application for roll contact printing

International Nuclear Information System (INIS)

Park, Jongho; Kim, Beomjoon

2016-01-01

Continuous fabrication of micropatterns at low-cost is attracting attention in various applications within industrial fields. To meet such demands, we have demonstrated a roll contact printing technique, using roller type polydimethylsiloxane (PDMS) stamps with roll-to-flat and roll-to-roll stages. Roller type PDMS stamps for roll contact printing were fabricated using a custom-made metal support and SU-8 microstructures fabricated on concave substrates as a mold. The molding/casting method which we developed here provided faster and easier fabrication than conventional methods for roller type stamps. Next, roll contact printing was performed using fabricated roller type PDMS stamps with roll-to-flat and roll-to-roll stages. Patterns with minimum widths of 3 μm and 2.1 μm were continuously fabricated for each stage, respectively. In addition, the relationship between applied pressures and dimensional changes of roll contact printed patterns was investigated. Finally, we confirmed that roll contact printing and the new fabrication method for roller stamps presented in this study demonstrated the feasibility for industrial applications. (paper)

Visualization in mechanics: the dynamics of an unbalanced roller

Science.gov (United States)

Cumber, Peter S.

2017-04-01

It is well known that mechanical engineering students often find mechanics a difficult area to grasp. This article describes a system of equations describing the motion of a balanced and an unbalanced roller constrained by a pivot arm. A wide range of dynamics can be simulated with the model. The equations of motion are embedded in a graphical user interface for its numerical solution in MATLAB. This allows a student's focus to be on the influence of different parameters on the system dynamics. The simulation tool can be used as a dynamics demonstrator in a lecture or as an educational tool driven by the imagination of the student. By way of demonstration the simulation tool has been applied to a range of roller-pivot arm configurations. In addition, approximations to the equations of motion are explored and a second-order model is shown to be accurate for a limited range of parameters.

Effects of frequency on gross efficiency and performance in roller ski skating.

Science.gov (United States)

Leirdal, S; Sandbakk, O; Ettema, G

2013-06-01

The purpose of the present study was to examine the effect of frequency on efficiency and performance during G3 roller ski skating. Eight well-trained male cross-country skiers performed three submaximal 5-min speeds (10, 13, and 16 km/h) and a time-to-exhaustion (TTE) performance (at 20 km/h) using the G3 skating technique using freely chosen, high, and low frequency at all four speeds. All tests were done using roller skis on a large treadmill at 5% incline. Gross efficiency (GE) was calculated as power divided by metabolic rate. Power was calculated as the sum of power against frictional forces and power against gravity. Metabolic rate was calculated from oxygen consumption and blood lactate concentration. Freely chosen frequency increased from 60 to 70 strokes/min as speed increased from 10 to 20 km/h. GE increased with power. At high power (20 km/h performance test), both efficiency and performance were significantly reduced by high frequency. In regard to choice of frequency during G3 roller ski skating, cross-country skiers seems to be self-optimized both in relation to energy saving (efficiency) and performance (TTE). © 2011 John Wiley & Sons A/S.

Air riding seal with purge cavity

Science.gov (United States)

Sexton, Thomas D; Mills, Jacob A

2017-08-15

An air riding seal for a turbine in a gas turbine engine, where an annular piston is axial moveable within an annular piston chamber formed in a stator of the turbine and forms a seal with a surface on the rotor using pressurized air that forms a cushion in a pocket of the annular piston. A purge cavity is formed on the annular piston and is connected to a purge hole that extends through the annular piston to a lower pressure region around the annular piston or through the rotor to an opposite side. The annular piston is sealed also with inner and outer seals that can be a labyrinth seal to form an additional seal than the cushion of air in the pocket to prevent the face of the air riding seal from overheating.

The directors’ roles in containing the Robben Island Diversity Experience (RIDE

Directory of Open Access Journals (Sweden)

Frans Cilliers

2012-03-01

Research purpose: The purpose of the research was to describe the experiences of the directors of RIDE in the last 10 years. Motivation for the study: Of the many and different diversity events that South African organisations present, RIDE is the only systems psycho-dynamically designed and presented event. This research was an effort to explore the nature of the directors’ roles in working with unconscious diversity dynamics in such a provocative venue. Research design, approach and method: The researchers conducted qualitative, descriptive and double hermeneutic research. The various RIDE events served as case studies. The data consisted of researcher field notes collected during the 10 years. Thematic analysis resulted in four themes, for which the researchers formulated working hypotheses. They integrated them into the research hypothesis. Main findings: Four themes emerged. They were the diversity characteristics of the directors as containers, working on the boundary between RIDE and the macro role players, attacks on the programme as container and challenges from participants. Practical/managerial implications: The research highlighted the important roles of directors’ authorisation as a resilience factor in containing RIDE. Contribution/value-add: The research contributed towards the awareness of intergroup relations between role players during diversity dynamic events and of how authorisation cements relationships.

A qualitative study of gender and work in a British riding school

OpenAIRE

Calamatta, Katherine F G

2012-01-01

This thesis focuses on employees of the horse riding school sector within the United Kingdom. It is based on qualitative fieldwork at two riding schools that took place over the course of three years and asks two questions: why do women numerically dominate within the setting of the riding school? How can we best understand this phenomenon using sociological literature? The subject for this thesis was motivated by my own prior experience as a worker within this industry.\\ud \\ud The thesis wil...

A Comparison Study on the Assessment of Ride Comfort for LRT Passengers

Science.gov (United States)

Tengku Munawir, Tengku Imran; Abqari Abu Samah, Ahmad; Afiq Akmal Rosle, Muhammad; Azlis-Sani, Jalil; Hasnan, Khalid; Sabri, S. M.; Ismail, S. M.; Yunos, Muhammad Nur Annuar Mohd; Yen Bin, Teo

2017-08-01

Ride comfort in railway transportation is very mind boggling and it relies on different dynamic performance criteria as well as subjective observation from the train passengers. Vibration discomfort from different elements such as vehicle condition, track area condition and working condition can prompt poor ride comfort. However, there are no universal applicable standards to analyse the ride comfort. There are several factors including local condition, vehicle condition and the track condition. In this current work, level of ride comfort by previous Adtranz-Walker light rapid transit (LRT) passengers at Ampang line were analysed. A comparison was done via two possible methods which are BS EN 12299 (2009) and Sperling’s Ride Index equation. BS EN 12299 standard is used to measure and evaluate the ride comfort of seating (Nvd) and standing (Nva) of train passenger in three different routes. Next, Sperling’s ride comfort equation is used to conduct validation and comparison between the obtained data. The result indicates a higher extent of vibration in the vertical axis which impacts the overall result. The standing position demonstrates a higher exposure of vibration in all the three tested routes. Comparison of the ride comfort assessment of passenger in sitting and standing position for both methods indicates that all the track sections exceeds “pronounced but not unpleasant (medium)” limit range. Nevertheless, the seating position at track section AU did not exceed the limit and stayed at the comfortable zone. The highest discomfort level achieved for both methods for seating position are 3.34 m/s2 for Nva and 2.63 m/s2 respectively, which is at route C uptrack that is from Chan Sow Lin station to Sri Petaling station. Meanwhile, the highest discomfort level achieved for both methods for standing are 3.80 m/s2 for Nvd and 2.88 m/s2 for Wz respectively, at uptrack section which is from Sri Petaling station to Chan Sow Lin station. Thus, the highest

Flexible fault ride through strategy for wind farm clusters in power systems with high wind power penetration

International Nuclear Information System (INIS)

Wang, Songyan; Chen, Ning; Yu, Daren; Foley, Aoife; Zhu, Lingzhi; Li, Kang; Yu, Jilai

2015-01-01

Highlights: • A flexible fault ride through strategy is proposed. • The strategy comprises of grid code requirements and power restrictions. • Slight faults and moderate faults are the main defending objectives. • Temporary overloading capability of the doubly fed induction generator is considered. - Abstract: This paper investigates a flexible fault ride through strategy for power systems in China with high wind power penetration. The strategy comprises of adaptive fault ride through requirements and maximum power restrictions of the wind farms with weak fault ride through capabilities. The slight faults and moderate faults with high probability are the main defending objective of the strategy. The adaptive fault ride through requirement in the strategy consists of two sub fault ride through requirements, a temporary slight voltage ride through requirement corresponding to a slight fault incident, with a moderate voltage ride through requirement corresponding to a moderate fault. The temporary overloading capability of the wind farm is reflected in both requirements to enhance the capability to defend slight faults and to avoid tripping when the crowbar is disconnected after moderate faults are cleared. For those wind farms that cannot meet the adaptive fault ride through requirement, restrictions are put on the maximum power output. Simulation results show that the flexible fault ride through strategy increases the fault ride through capability of the wind farm clusters and reduces the wind power curtailment during faults

Plutonium explosive dispersal modeling using the MACCS2 computer code

International Nuclear Information System (INIS)

Steele, C.M.; Wald, T.L.; Chanin, D.I.

1998-01-01

The purpose of this paper is to derive the necessary parameters to be used to establish a defensible methodology to perform explosive dispersal modeling of respirable plutonium using Gaussian methods. A particular code, MACCS2, has been chosen for this modeling effort due to its application of sophisticated meteorological statistical sampling in accordance with the philosophy of Nuclear Regulatory Commission (NRC) Regulatory Guide 1.145, ''Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants''. A second advantage supporting the selection of the MACCS2 code for modeling purposes is that meteorological data sets are readily available at most Department of Energy (DOE) and NRC sites. This particular MACCS2 modeling effort focuses on the calculation of respirable doses and not ground deposition. Once the necessary parameters for the MACCS2 modeling are developed and presented, the model is benchmarked against empirical test data from the Double Tracks shot of project Roller Coaster (Shreve 1965) and applied to a hypothetical plutonium explosive dispersal scenario. Further modeling with the MACCS2 code is performed to determine a defensible method of treating the effects of building structure interaction on the respirable fraction distribution as a function of height. These results are related to the Clean Slate 2 and Clean Slate 3 bunkered shots of Project Roller Coaster. Lastly a method is presented to determine the peak 99.5% sector doses on an irregular site boundary in the manner specified in NRC Regulatory Guide 1.145 (1983). Parametric analyses are performed on the major analytic assumptions in the MACCS2 model to define the potential errors that are possible in using this methodology

Plutonium explosive dispersal modeling using the MACCS2 computer code

Energy Technology Data Exchange (ETDEWEB)

Steele, C.M.; Wald, T.L.; Chanin, D.I.

1998-11-01

The purpose of this paper is to derive the necessary parameters to be used to establish a defensible methodology to perform explosive dispersal modeling of respirable plutonium using Gaussian methods. A particular code, MACCS2, has been chosen for this modeling effort due to its application of sophisticated meteorological statistical sampling in accordance with the philosophy of Nuclear Regulatory Commission (NRC) Regulatory Guide 1.145, ``Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants``. A second advantage supporting the selection of the MACCS2 code for modeling purposes is that meteorological data sets are readily available at most Department of Energy (DOE) and NRC sites. This particular MACCS2 modeling effort focuses on the calculation of respirable doses and not ground deposition. Once the necessary parameters for the MACCS2 modeling are developed and presented, the model is benchmarked against empirical test data from the Double Tracks shot of project Roller Coaster (Shreve 1965) and applied to a hypothetical plutonium explosive dispersal scenario. Further modeling with the MACCS2 code is performed to determine a defensible method of treating the effects of building structure interaction on the respirable fraction distribution as a function of height. These results are related to the Clean Slate 2 and Clean Slate 3 bunkered shots of Project Roller Coaster. Lastly a method is presented to determine the peak 99.5% sector doses on an irregular site boundary in the manner specified in NRC Regulatory Guide 1.145 (1983). Parametric analyses are performed on the major analytic assumptions in the MACCS2 model to define the potential errors that are possible in using this methodology.

Driving self-regulation and ride service utilization in a multicommunity, multistate sample of U.S. older adults.

Science.gov (United States)

Bird, Donna C; Freund, Katherine; Fortinsky, Richard H; Staplin, Loren; West, Bethany A; Bergen, Gwen; Downs, Jonathan

2017-04-03

This study examined a multicommunity alternative transportation program available 24 hours a day, 7 days a week, for any purpose, offering door-through-door service in private automobiles to members who either do not drive or are transitioning away from driving. Specific aims were to describe the characteristics of members by driving status and ride service usage of these members. Data came from administrative records maintained by a nonprofit ride service program and include 2,661 individuals aged 65+ residing in 14 states who joined the program between April 1, 2010, and November 8, 2013. Latent class analysis was used to group current drivers into 3 classes of driving status of low, medium, and high self-regulation, based on their self-reported avoidance of certain driving situations and weekly driving frequency. Demographics and ride service use rate for rides taken through March 31, 2014, by type of ride (e.g., medical, social, etc.) were calculated for nondrivers and drivers in each driving status class. The majority of ride service users were female (77%) and aged 65-74 years (82%). The primary method of getting around when enrolling for the transportation service was by riding with a friend or family member (60%). Among the 67,883 rides given, nondrivers took the majority (69%) of rides. Medical rides were the most common, accounting for 40% of all rides. Reported ride usage suggests that older adults are willing to use such ride services for a variety of trips when these services are not limited to specific types (e.g., medical). Further research can help tailor strategies to encourage both nondrivers and drivers to make better use of alternative transportation that meets the special needs of older people.

Vibratory synchronization transmission of a cylindrical roller in a vibrating mechanical system excited by two exciters

Science.gov (United States)

Zhang, Xueliang; Wen, Bangchun; Zhao, Chunyu

2017-11-01

In present work vibratory synchronization transmission (VST) of a cylindrical roller with dry friction in a vibrating mechanical system excited by two exciters, is studied. Using the average method, the criterion of implementing synchronization of two exciters and that of ensuring VST of a roller, are achieved. The criterion of stability of the synchronous states satisfies the Routh-Hurwitz principle. The influences of the structural parameters of the system to synchronization and stability, are discussed numerically, which can be served as the theoretical foundation for engineering designs. An experiment is carried out, which approximately verify the validity of the theoretical and numerical results, as well as the feasibility of the method used. Utilizing the VST theory of a roller, some types of vibrating crushing or grinding equipments, etc., can be designed.

Hippotherapy and Therapeutic Riding Highlight!

Science.gov (United States)

Apel, Laura, Comp.

2007-01-01

Horses have always been appreciated by humans for their strength, beauty, and gentle demeanor. Children, especially, have gravitated toward them and many experience their first horseback riding lesson at a young age. However, horses can play a very different role in the lives of children and adults with disabilities. Hippotherapy is physical,…

Granule fraction inhomogeneity of calcium carbonate/sorbitol in roller compacted granules

DEFF Research Database (Denmark)

Bacher, Charlotte; Olsen, P.M.; Bertelsen, P.

2008-01-01

The granule fraction inhomogeneity of roller compacted granules was examined on mixtures of three different morphologic forms of calcium carbonate and three particle sizes of sorbitol. The granule fraction inhomogeneity was determined by the distribution of the calcium carbonate in each of the 10...... size fractions between 0 and 2000 µm and by calculating the demixing potential. Significant inhomogeneous occurrence of calcium carbonate in the size fractions was demonstrated, depending mostly on the particles sizes of sorbitol but also on the morphological forms of calcium carbonate......, the ability of the powder to agglomerate in the roller compactor was demonstrated to be related to the ability of the powder to be compacted into a tablet, thus the most compactable calcium carbonate and the smallest sized sorbitol improved the homogeneity by decreasing the demixing potential....

The contribution of attention in virtual moped riding training of teenagers.

Science.gov (United States)

Tagliabue, Mariaelena; Da Pos, Osvaldo; Spoto, Andrea; Vidotto, Giulio

2013-08-01

Riding a moped, like many other everyday activities, is a complex behavior in which attention plays a crucial role. This study aims to investigate the role of attention in enhancing the skills required to ride a moped simulator. Two experiments were conducted with 207 and 60 students (14-15 years old), respectively, using a moped simulator to ride on 12 different tracks. The assignment was to ride safely and avoid hazards. In experiment 1, we divided the hazard scenes of the tracks on the basis of the fact that a shift in attention was required to escape the danger. We showed that during the riding training, when no attentional shift was required, the ability to avoid hazards was constantly higher. In experiment 2, participants were asked to cope with the same basic experimental setting but with an additional attentive task. The results showed that they performed in such a way that not only did the attentive task not impair their performance, but it also produced an improvement in the ability to shift attentional focus, preserving performance efficiency. On the basis of these data, it can be claimed that, primarily, attentional shift plays a prominent role in accounting for accident circumstances. Secondarily, it can be claimed that attentional training contributes to improved processing efficiency so as to prevent mishaps. Copyright © 2013 Elsevier Ltd. All rights reserved.

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, For Calendar Year 2010

International Nuclear Information System (INIS)

2011-01-01

This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Units (CAUs) located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2010 and includes inspection and repair activities completed at the following seven CAUs: (1) CAU 400: Bomblet Pit and Five Points Landfill (TTR); (2) CAU 407: Roller Coaster RadSafe Area (TTR); (3) CAU 424: Area 3 Landfill Complexes (TTR); (4) CAU 426: Cactus Spring Waste Trenches (TTR); (5) CAU 453: Area 9 UXO Landfill (TTR); (6) CAU 484: Surface Debris, Waste Sites, and Burn Area (TTR); and (7) CAU 487: Thunderwell Site (TTR).

Beyond velocity and acceleration: jerk, snap and higher derivatives

Science.gov (United States)

Eager, David; Pendrill, Ann-Marie; Reistad, Nina

2016-11-01

The higher derivatives of motion are rarely discussed in the teaching of classical mechanics of rigid bodies; nevertheless, we experience the effect not only of acceleration, but also of jerk and snap. In this paper we will discuss the third and higher order derivatives of displacement with respect to time, using the trampolines and theme park roller coasters to illustrate this concept. We will also discuss the effects on the human body of different types of acceleration, jerk, snap and higher derivatives, and how they can be used in physics education to further enhance the learning and thus the understanding of classical mechanics concepts.

Influence of quartz particles on wear in vertical roller mills

DEFF Research Database (Denmark)

Jensen, Lucas R.D.; Friis, Henrik; Fundal, Erling

2010-01-01

The standard closed circuit comminution process commonly employed in industrial vertical roller mills has been analyzed to determine the influence of typical abrasive minerals on wear rates. With the main focus on raw mixes used in cement plants, synthetic mixtures imitating were prepared. Using...

Prevention of Roller Bearing-Initiated Burnoffs in Railroad Freight Car Journals

Science.gov (United States)

1979-01-01

The objective of this program was to determine the technical feasibility and cost effectiveness of constructing three separate devices for the prevention of catastrophic roller bearing-initiated, railroad journal failure. 1. Construction of a low cos...

Practical Secure Transaction for Privacy-Preserving Ride-Hailing Services

Directory of Open Access Journals (Sweden)

Chenglong Cao

2018-01-01

Full Text Available Ride-hailing service solves the issue of taking a taxi difficultly in rush hours. It is changing the way people travel and has had a rapid development in recent years. Since the service is offered over the Internet, there is a great deal of uncertainty about security and privacy. Focusing on the issue, we changed payment pattern of existing systems and designed a privacy protection ride-hailing scheme. E-cash was generated by a new partially blind signature protocol that achieves e-cash unforgeability and passenger privacy. Particularly, in the face of a service platform and a payment platform, a passenger is still anonymous. Additionally, a lightweight hash chain was constructed to keep e-cash divisible and reusable, which increases practicability of transaction systems. The analysis shows that the scheme has small communication and computation costs, and it can be effectively applied in the ride-hailing service with privacy protection.

Control of Doubly-Fed Induction Generator to Ride-Through Recurring Grid Faults

DEFF Research Database (Denmark)

Chen, Wenjie; Xu, Dehong; Zhu, Nan

2016-01-01

The wind turbine system (WTS) is required to ride-through recurring grid faults by the new grid codes. Under single grid faults, the fault ride-through (FRT) strategy with rotor-side crowbar is normally used for the doubly-fed induction generator (DFIG) WTS. However, under recurring faults, larger...... transient current and voltage may be produced, and the DFIG may fail to ride-through the second fault even with the rotor-side crowbar. The crowbar can be active again during the voltage recovery, but large electromagnetic torque (EM-torque) fluctuations will be introduced. The reliability of the mechanical...... system will be influenced. In this paper, an FRT strategy for the DFIG WTS to ride-through recurring symmetrical grid faults is investigated. An improved control strategy is introduced and it is applied during the voltage recovery of the grid faults. The decay of the stator natural flux can...

Sustainable Passenger Transportation: Dynamic Ride-Sharing

NARCIS (Netherlands)

N.A.H. Agatz (Niels); A. Erera (Alan); M.W.P. Savelsbergh (Martin); X. Wang (Xing)

2010-01-01

textabstractRide-share systems, which aim to bring together travelers with similar itineraries and time schedules, may provide significant societal and environmental benefits by reducing the number of cars used for personal travel and improving the utilization of available seat capacity. Effective

Physical and mechanical behaviour of a roller compacted concrete ...

African Journals Online (AJOL)

In order to study the behaviour of a roller compacted concrete (RCC) reinforced with polypropylene fiber, six types of RCC were made with different content of fibers (0, 0.5, 1, 1.5, 2 and 2.5 Kg/m3). The physical parameters are the density, the workability, the shrinkage and the water absorption. For the mechanical ...

"Paul Revere's Ride": Awakening Abolitionists

Science.gov (United States)

Lepore, Jill

2011-01-01

Henry Wadsworth Longfellow used to be both the best-known poet in the English-speaking world and the most beloved, adored by the learned and the lowly alike, read by everyone from Nathaniel Hawthorne and Abraham Lincoln to John Ruskin and Queen Victoria--and, just as avidly, by the queen's servants. "Paul Revere's Ride" is Longfellow's best-known…

Paediatric ride-on mower related injuries and plastic surgical management.

LENUS (Irish Health Repository)

Laing, T A

2011-05-01

Lawnmower related injuries cause significant morbidity in children and young teenagers. The \\'ride-on\\' mowers which are more powerful than the \\'walk behind\\' mowers are becoming increasingly popular. The incidence and severity of injuries from either type of lawnmower appears to be steadily rising as is the burden placed on local plastic surgical and emergency services in managing the care of these patients. The aims of the study were to demonstrate changing trends in lawnmower-related injuries to children presenting to a single unit over a ten-year period and to identify any association between injury severity and machine subtype (\\'ride-on\\' versus \\'walk-behind\\'). Hospital databases, theatre records and medical case notes were reviewed retrospectively of all patients under the age of 16 treated for lawnmower related injuries over a 10 year period from July 1998 to June 2008. Data gathered included patient demographics, injury site and severity, management (type and number of surgical procedures), length of hospital stay and outcome. Injury severity score was also calculated for each case. Controlling for estimated regional population changes, there was a significant increase in the number of ride-on mower related accidents in the time period 2003-2008, compared to the time period 1998-2003. Ride-on injuries had significantly higher injury severity scores, longer hospital stays and were more likely to involve amputations as compared with walk-behind injuries. Children can sustain significant injuries with unsafe lawnmower use. The current study demonstrates the increasing incidence of ride-on mower related injuries in children and identifies a greater morbidity associated with such injuries. Such presentations place intense demands on local plastic surgical services.

Experimental performance investigation of glazing system combined with internal roller blinds

DEFF Research Database (Denmark)

Larsen, Olena Kalyanova; Jensen, Rasmus Lund; Iversen, Tore Dahl

2016-01-01

Modern low-energy buildings are often associated with efficient shading devices, as an inevitable component to reduce the peak heat gain in the building and to improve visual comfort. Internal shading devices may have inferior performance compared to external shading, but these are still the most...... used in practice due to lower cost, simplicity and better acceptance between architects and users. The interplay between glazing systems and internal shading devices has been studied and in everyday practice this interplay is described by the solar shading coefficient and the total g......-value of the system (window + roller blind). Solar shading coefficient in such practice is assumed to be independent of the window properties and solar incidence angle. This paper is aimed to illustrate the deviation between the actual and assumed performance of the window system with internal roller blind. This task...

On-demand high-capacity ride-sharing via dynamic trip-vehicle assignment.

Science.gov (United States)

Alonso-Mora, Javier; Samaranayake, Samitha; Wallar, Alex; Frazzoli, Emilio; Rus, Daniela

2017-01-17

Ride-sharing services are transforming urban mobility by providing timely and convenient transportation to anybody, anywhere, and anytime. These services present enormous potential for positive societal impacts with respect to pollution, energy consumption, congestion, etc. Current mathematical models, however, do not fully address the potential of ride-sharing. Recently, a large-scale study highlighted some of the benefits of car pooling but was limited to static routes with two riders per vehicle (optimally) or three (with heuristics). We present a more general mathematical model for real-time high-capacity ride-sharing that (i) scales to large numbers of passengers and trips and (ii) dynamically generates optimal routes with respect to online demand and vehicle locations. The algorithm starts from a greedy assignment and improves it through a constrained optimization, quickly returning solutions of good quality and converging to the optimal assignment over time. We quantify experimentally the tradeoff between fleet size, capacity, waiting time, travel delay, and operational costs for low- to medium-capacity vehicles, such as taxis and van shuttles. The algorithm is validated with ∼3 million rides extracted from the New York City taxicab public dataset. Our experimental study considers ride-sharing with rider capacity of up to 10 simultaneous passengers per vehicle. The algorithm applies to fleets of autonomous vehicles and also incorporates rebalancing of idling vehicles to areas of high demand. This framework is general and can be used for many real-time multivehicle, multitask assignment problems.

Hardness of Preemptive Finite Capacity Dial-a-Ride

DEFF Research Database (Denmark)

Gørtz, Inge Li

2006-01-01

In the Finite Capacity Dial-a-Ride problem the input is a metric space, a set of objects, each specifying a source and a destination, and an integer k---the capacity of the vehicle used for making the deliveries. The goal is to compute a shortest tour for the vehicle in which all objects can...... and Raghavachari [FOCS '98] gave a min{O(log N),O(k)}-approximation algorithm for the preemptive version of the problem. In this paper we show that the preemptive Finite Capacity Dial-a-Ride problem has no $min{O(log^{1/4-\\epsilon}N),k^{1-\\epsilon}}$-approximation algorithm for any $\\epsilon>0$ unless all problems...

Ride Control Systems - Reduced Motions on the Cost of Increased Sectional Forces ?

DEFF Research Database (Denmark)

Folsø, R.; Nielsen, Ulrik Dam; Torti, F.

2003-01-01

Implementation of passive and active ride control systems into both linear frequency and non-linear time domain strip theories is described. The ride control systems considered can consist of T-foils, fins or a combination of these. These appendages are taken into account by considering the lift...

Profiled Roller Stress/Fatigue Life Analysis Methodology and Establishment of an Appropriate Stress/Life Exponent

Science.gov (United States)

1997-01-01

The objective of this work was to determine the three dimensional volumetric stress field, surface pressure distribution and actual contact area between a 0.50" square roller with different crown profiles and a flat raceway surface using Finite Element Analysis. The 3-dimensional stress field data was used in conjunction with several bearing fatigue life theories to extract appropriate values for stress-life exponents. Also, results of the FEA runs were used to evaluate the laminated roller model presently used for stress and life prediction.

A Optimal Dimension Parameters Design of Needle Roller Bearings Considering Multi Factors Affecting Life

Science.gov (United States)

Bai, XiaoBo; Li, Bo

2017-12-01

Taking into many influencing factors, a Needle Roller Bearings life calculation model was established using the Influence coefficient method and ISO formula. Take this model as the optimization objective function, some optimization variables were determined, and these variables were added constraint conditions. Using dynamic nonlinear strategy to improve the inertia weight, the arccosine strategy to adjust the learning factor, function constraints was solved by the methods of ensure particle legitimacy. Nonlinear optimization design of cylindrical roller bearings was realized by Improved Particle Swarm Algorithm. The proposed method of bearing design was verified effective by test of the optimization results.

The Induced Seismicity Roller Coaster: Up, and then Down, and then Up Again

Science.gov (United States)

Riffault, J.; Dempsey, D.

2017-12-01

Diverse industries from oil & gas, to geothermal and CO2 storage have triggered significant numbers of earthquakes in the last decade. There is broad agreement that the underlying cause is injection of large volumes of fluid and subsequent pressure rise in the disposal and connected formations. Thus, it stands to reason that reducing injection will have a flow-through effect on the seismicity. For example, in an attempt to mitigate earthquakes in Oklahoma, a 40% injection rate reduction was enforced, resulting in a significant decrease in the seismicity rate. Here, we show that, under certain conditions, cutting the injection rate leads to transients in the seismicity rate that could mislead operators and regulators into a false sense of security. We used semi-analytic solutions of injection and fluid flow in a radial geometry coupled with a model that links the pressure rise with the rate of induced seismicity. We find that cutting the injection rate causes complex pressure transients around the injection well: (i) initially, pressure will continue to increase; (ii), then, it reaches a peak and starts to decline; (iii) finally, the decline is reversed and pressure starts to increase again. Depending on the stress criticality of the system and the size of the injection rate cut, the outcome can be a short-term decrease, or even a total cessation, of the seismicity. However, over the longer term, seismicity will increase to a new steady-state (which is nevertheless lower than that preceding the rate cut.) Our results imply that it can be misleading to rely on observations of the seismicity rate shortly after mitigation measures are implemented as an indicator of their efficacy. It is also possible to use this model to interpret the results injection well step tests, with the aim of quantifying aspects of the crustal stress state.

California Amusement Rides and Liability

Science.gov (United States)

Epstein, Adam

2005-01-01

Twenty-three-year-old Cristina Moreno traveled from Spain to California for her honeymoon in 2000. As part of her visit, she rode the Indiana Jones amusement ride at Disneyland with her new husband. On June 25, 2000, she suffered a brain injury, and she eventually died on September 1, 2000, as a result of injuries allegedly sustained while riding…

Therapeutic Effects of Horseback Riding Interventions: A Systematic Review and Meta-analysis.

Science.gov (United States)

Stergiou, Alexandra; Tzoufi, Meropi; Ntzani, Evangelia; Varvarousis, Dimitrios; Beris, Alexandros; Ploumis, Avraam

2017-10-01

Equine-assisted therapies, such as therapeutic riding and hippotherapy, are believed to have positive physical and emotional effects in individuals with neuromotor, developmental, and physical disabilities. The purpose of this review was to determine whether therapeutic riding and hippotherapy improve balance, motor function, gait, muscle symmetry, pelvic movement, psychosocial parameters, and the patients' overall quality of life. In this study, a literature search was conducted on MEDLINE, CINAHL, MBASE, SportDiscus, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, PEDro, DARE, Google Scholar, and Dissertation Abstracts. Only studies with a control/comparison group or self-controlled studies performing preintervention and postintervention assessment were included. Excluded were (1) studies not providing data on baseline score or end-point outcome, (2) single-subject studies, (3) studies providing only qualitative data, and (4) studies that used a mechanical horse. Sixteen trials were included. The methodologic quality of each study was evaluated using Downs and Black quality assessment tool. Most of the studies showed a trend toward a beneficial effect of therapeutic riding and hippotherapy on balance and gross motor function. The meta-analysis showed improvement in both the Berg Balance Scale and the Gross Motor Function Measure in therapeutic riding and hippotherapy programs. Programs such as therapeutic riding and hippotherapy are a viable intervention option for patients with balance, gait, and psychomotor disorders.

Intelligence diagnosis method for roller bearings using features of AE signal

International Nuclear Information System (INIS)

Pan, J; Wang, H Q; Wang, F; Yang, J F; Liu, W B

2012-01-01

Rolling bearings are important components in rotating machines, which are wildly used in industrial production. The fault diagnosis technology plays a very important role for quality and life of machines. Based on symptom parameters of acoustic emission (AE) signals, this paper presents an intelligent diagnosis method for roller bearings using the principal component analysis, rough sets, and BP neural network to detect faults and distinguish fault types. The principal component analysis and the rough sets algorithm are used to reduce details of time-domain symptom parameters for training the BP neural network. The BP neural network, which is used for condition diagnosis of roller bearings, can obtain good convergence using the symptom parameters acquired by the principal component analysis and the rough sets during learning, and automatically distinguish fault types during diagnosing. Practical examples are provided to verify the efficiency of the proposed method.

A roller-like bird (Coracii) from the Early Eocene of Denmark.

Science.gov (United States)

Bourdon, Estelle; Kristoffersen, Anette V; Bonde, Niels

2016-09-27

The fossil record of crown group birds (Neornithes) prior to the Cretaceous-Paleogene boundary is scarce and fragmentary. Early Cenozoic bird fossils are more abundant, but are typically disarticulated and/or flattened. Here we report the oldest roller (Coracii), Septencoracias morsensis gen. et sp. nov. (Primobucconidae), based on a new specimen from the Early Eocene (about 54 million years ago) Fur Formation of Denmark. The new fossil is a nearly complete, three-dimensionally preserved and articulated skeleton. It lies at the lower end of the size range for extant rollers. Salient diagnostic features of Septencoracias relative to other Coracii include the proportionally larger skull and the small, ovoid and dorsally positioned narial openings. Our discovery adds to the evidence that the Coracii had a widespread northern hemisphere distribution in the Eocene. Septencoracias is the oldest substantial record of the Picocoraciae and provides a reliable calibration point for molecular phylogenetic studies.

Severe Sunburn After a Hot Air Balloon Ride: A Case Report and Literature Review.

Science.gov (United States)

Ozturk, Sinan; Karagoz, Huseyin

2015-01-01

Hot air balloon tours are very popular among travelers worldwide. Preventable burn injuries associated with hot air balloon rides have been reported during crashes into power lines, in propane burner explosions, and following contact with the propane burner tanks. We present a case of severe repeated sunburn, which poses another risk of preventable injury during hot air balloon rides, and briefly discuss the injury epidemiology of hot air balloon rides. © 2015 International Society of Travel Medicine.

Effects of alcohol on motorcycle riding skills

Science.gov (United States)

2007-12-01

Alcohol is known to disrupt the effect of neurotransmitters and impair various psychomotor skills. Indeed, alcohol intoxication is a significant risk factor for fatal traffic crashes, especially when riding a motorcycle. At present, there is sparse r...

Fire ants protect mealybugs against their natural enemies by utilizing the leaf shelters constructed by the leaf roller Sylepta derogata.

Directory of Open Access Journals (Sweden)

Aiming Zhou

Full Text Available The importance of mutualism is receiving more attention in community ecology. In this study, the fire ant Solenopsis invicta was found to take advantage of the shelters constructed by the leaf roller Sylepta derogata to protect mealybugs (Phenacoccus solenopsis against their natural enemies. This protective effect of fire ant tending on the survival of mealybugs in shelters was observed when enemies and leaf rollers were simultaneously present. Specifically, fire ants moved the mealybugs inside the shelters produced by S. derogata on enemy-infested plants. Compared with that in plants without ants, the survival of mealybugs in shelters in the presence of natural enemies in plants with ants markedly improved. Both the protection of ants and the shelters provided by leaf rollers did not affect the survival of mealybugs in the absence of enemies in plants. Ants and leaf rollers significantly improved the survival of mealybugs in predator-infested plants, whereas no such improvement was observed in parasitoid-infested ones.

On Calculation Methods and Results for Straight Cylindrical Roller Bearing Deflection, Stiffness, and Stress

Science.gov (United States)

Krantz, Timothy L.

2011-01-01

The purpose of this study was to assess some calculation methods for quantifying the relationships of bearing geometry, material properties, load, deflection, stiffness, and stress. The scope of the work was limited to two-dimensional modeling of straight cylindrical roller bearings. Preparations for studies of dynamic response of bearings with damaged surfaces motivated this work. Studies were selected to exercise and build confidence in the numerical tools. Three calculation methods were used in this work. Two of the methods were numerical solutions of the Hertz contact approach. The third method used was a combined finite element surface integral method. Example calculations were done for a single roller loaded between an inner and outer raceway for code verification. Next, a bearing with 13 rollers and all-steel construction was used as an example to do additional code verification, including an assessment of the leading order of accuracy of the finite element and surface integral method. Results from that study show that the method is at least first-order accurate. Those results also show that the contact grid refinement has a more significant influence on precision as compared to the finite element grid refinement. To explore the influence of material properties, the 13-roller bearing was modeled as made from Nitinol 60, a material with very different properties from steel and showing some potential for bearing applications. The codes were exercised to compare contact areas and stress levels for steel and Nitinol 60 bearings operating at equivalent power density. As a step toward modeling the dynamic response of bearings having surface damage, static analyses were completed to simulate a bearing with a spall or similar damage.

Roller skating--is it a dangerous sport?

Science.gov (United States)

Tse, P Y; Shen, W Y; Chan, K M; Leung, P C

1987-01-01

A prospective survey of 111 cases of roller skating injuries within one year are reported. Males were more commonly injured than females. There was a high incidence (86%) of serious injuries, 28% of which required surgical treatment. The wrist (23%) was the commonest region involved, followed by the shoulder (20%), the elbow (15%) and the ankle (12%). Collision with other skaters and loss of control were the main factors leading to injury. Better rink discipline, instruction classes and safety publicity should be helpful in minimising accidents. Images Fig. 2 & Fig. 3 PMID:3676638

Intermittent stick-slip dynamics during the peeling of an adhesive tape from a roller.

Science.gov (United States)

Cortet, Pierre-Philippe; Dalbe, Marie-Julie; Guerra, Claudia; Cohen, Caroline; Ciccotti, Matteo; Santucci, Stéphane; Vanel, Loïc

2013-02-01

We study experimentally the fracture dynamics during the peeling at a constant velocity of a roller adhesive tape mounted on a freely rotating pulley. Thanks to a high speed camera, we measure, in an intermediate range of peeling velocities, high frequency oscillations between phases of slow and rapid propagation of the peeling fracture. This so-called stick-slip regime is well known as the consequence of a decreasing fracture energy of the adhesive in a certain range of peeling velocity coupled to the elasticity of the peeled tape. Simultaneously with stick slip, we observe low frequency oscillations of the adhesive roller angular velocity which are the consequence of a pendular instability of the roller submitted to the peeling force. The stick-slip dynamics is shown to become intermittent due to these slow pendular oscillations which produce a quasistatic oscillation of the peeling angle while keeping constant the peeling fracture velocity (averaged over each stick-slip cycle). The observed correlation between the mean peeling angle and the stick-slip amplitude questions the validity of the usually admitted independence with the peeling angle of the fracture energy of adhesives.

The Effects of Ride Hailing Services on Travel and Associated Greenhouse Gas Emissions

Science.gov (United States)

2018-04-01

Towards the close of the first decade of the 21st Century, ride-hailing services began to enter the transportation market through smart phone applications that allowed consumers to hail and pay for a ride from drivers using their own vehicle. The inf...

Stay Safe Riding Bikes or Skating Outside

Centers for Disease Control (CDC) Podcasts

2011-02-02

In this podcast for kids, the Kidtastics talk about safety when outside, riding bikes or skating.  Created: 2/2/2011 by National Center for Injury Prevention and Control (NCIPC).   Date Released: 2/2/2011.

Simulation of accelerated strip cooling on the hot rolling mill run-out roller table

Directory of Open Access Journals (Sweden)

E.Makarov

2016-07-01

Full Text Available A mathematical model of the thermal state of the metal in the run-out roller table continuous wide hot strip mill. The mathematical model takes into account heat generation due to the polymorphic γ → α transformation of supercooled austenite phase state and the influence of the chemical composition of the steel on the physical properties of the metal. The model allows calculation of modes of accelerated cooling strips on run-out roller table continuous wide hot strip mill. Winding temperature calculation error does not exceed 20°C for 98.5 % of strips of low-carbon and low-alloy steels

Ride Quality Assessment of Bus Suspension System through Modal Frequency Response Approach

Directory of Open Access Journals (Sweden)

Y. S. Kong

2014-09-01

Full Text Available The ride dynamic characteristics of an urban bus were investigated through simulations with suspension component characteristics and were validated through field measurements. It was performed on highway road at a constant forward speed. A random vibration bus model with two parallel tracks of terrain profile was synthesized with superposition between the left and right sides as well as time delay between front and rear. The bus frequency response model was introduced with embedded modal extraction data to enhance computation efficiency. The simulation results of the bus model were derived in terms of acceleration PSD and frequency-weighted root mean square acceleration along the vertical axes at three locations, namely, driver side, middle, and rear passenger side, to obtain the overall bus ride performance. Another two sets of new leaf spring design were proposed as suspension parameter analysis. The simulation approach provides reasonably good results in evaluating passenger perception on ride and shows that the proposed new spring design can significantly improve the ride quality of the driver and passengers.

Roller kiln with very low fluoride emission. The Ecokiln

Energy Technology Data Exchange (ETDEWEB)

Reymer, P.S.; Denissen, A.M. [TNO TPD Materials Research and Technology, Eindhoven (Netherlands)

2001-09-01

In most European countries the limit for fluoride emission in ceramic kiln flue gases is set at 5 mg HF/m{sup 3} flue gas. In cooperation with Royal Mosa, Royal Sphinx, Gasunie in the Netherlands and Sacmi, Italy, a roller kiln has been developed which can operate below the fore-mentioned limit. Also, a flue gas cleaning device is not necessary. 4 refs.

Pricing Decision under Dual-Channel Structure considering Fairness and Free-Riding Behavior

Directory of Open Access Journals (Sweden)

Yongmei Liu

2014-01-01

Full Text Available Under dual-channel structure, the free-riding behavior based on different service levels between online channel and offline channel cannot be avoided, which would lead to channel unfairness. This study implies that the dual-channel supply chain is built up by online channel controlled by manufacturer and traditional channel controlled by retailer, respectively. Under this channel structure, we rebuild the linear demand function considering free-riding behavior and modify the pricing model based on channel fairness. Then the influences of fair factor and free-riding behavior on manufacturer and retailer pricing and performance are discussed. Finally, we propose some numerical analysis to provide some valuable recommendations for manufacturer and retailer improving channel management performance.

Simulation modeling of wheeled vehicle dynamics on the stand "Roller"

Directory of Open Access Journals (Sweden)

G. O. Kotiev

2014-01-01

Full Text Available The tests are an integral part of the wheeled vehicle design, manufacturing, and operation. The need for their conducting arises from the research and experimental activities to assess the qualitative and quantitative characteristics of the vehicles in general, as well as the individual components and assemblies. It is obvious that a variety of design features of wheeled vehicles request a development of methods both for experimental studies and for creating the original bench equipment for these purposes.The main positive feature of bench tests of automotive engineering is a broad capability to control the combinations of traction loads, speed rates, and external input conditions. Here, the steady state conditions can be used for a long time, allowing all the necessary measurements to be made, including those with video and photo recording experiment.It is known that the benefits of test "M" type (using a roller dynamometer include a wide range of test modes, which do not depend on the climatic conditions, as well as a capability to use a computer-aided testing programs. At the same time, it is known that the main drawback of bench tests of full-size vehicle is that the tire rolling conditions on the drum mismatch to the real road pavements, which are difficult to simulate on the drum surface. This problem can be solved owing to wheeled vehicle tests at the benches "Roller" to be, in efficiency, the most preferable research method. The article gives a detailed presentation of developed at BMSTU approach to its solving.Problem of simulation mathematical modeling has been solved for the vehicle with the wheel formula 8 × 8, and individual wheel-drive.The simulation results have led to the conclusion that the proposed principle to simulate a vehicle rolling on a smooth non-deformable support base using a bench " Roller " by simulation modeling is efficient.

Topology Optimization of Vehicle Body Structure for Improved Ride & Handling

OpenAIRE

Lövgren, Sebastian; Norberg, Emil

2011-01-01

Ride and handling are important areas for safety and improved vehicle control during driving. To meet the demands on ride and handling a number of measures can be taken. This master thesis work has focused on the early design phase. At the early phases of design, the level of details is low and the design freedom is big. By introducing a tool to support the early vehicle body design, the potential of finding more efficient structures increases. In this study, topology optimization of a vehicl...

Screw-released roller brake

Science.gov (United States)

Vranish, John M. (Inventor)

1999-01-01

A screw-released roller brake including an input drive assembly, an output drive assembly, a plurality of locking sprags, a mechanical tripper nut for unlocking the sprags, and a casing therefor. The sprags consist of three dimensional (3-D) sprag members having pairs of contact surface regions which engage respective pairs of contact surface regions included in angular grooves or slots formed in the casing and the output drive assembly. The sprags operate to lock the output drive assembly to the casing to prevent rotation thereof in an idle mode of operation. In a drive mode of operation, the tripper is either self actuated or motor driven and is translated linearly up and down against a spline and at the limit of its travel rotates the sprags which unlock while coupling the input drive assembly to the output drive assembly so as to impart a turning motion thereto in either a clockwise or counterclockwise direction.

Injuries associated with the use of riding mowers in the United States, 2002-2007.

Science.gov (United States)

Hammig, Bart; Childers, Elizabeth; Jones, Ches

2009-10-01

To examine injuries among patients treated in an emergency department (ED) related to the use of a riding lawn mower. Data were obtained from the National Electronic Injury Surveillance System for the years 2002-2007. National estimates of ED visits for injuries associated with the use of a riding lawn mower were analyzed. Narrative text entries were categorized to provide a detailed record of the circumstances precipitating the injury. Average annual rates were calculated and logistic regression analyses were employed to determine risk estimates for patient disposition and demographic characteristics related to ED visits for injuries associated with riding mowers. From 2002 through 2007, there were an estimated 66,341 ED visits for injuries related to the use of riding lawnmowers in the U.S., with an average annual rate of 6.0 ED visits per 100,000 males, and 1.6 ED visits per 100,000 females. Older adults had higher rates of ED visits for injuries (7.2/100,000) than younger age groups. The most common injuries involved contusions (24%); sprains/strains (22%) and fractures (17%). The majority of patients (90%) were treated and released the same day. Results of logistic regression analyses revealed that older adults were more likely to be hospitalized when compared to younger age groups; and incidents involving rollovers [OR=5.45 (95% CI=3.22-9.23)] and being run over [6.01 (95% CI 3.23-11.17)] were more likely to result in hospitalization when compared to all other circumstances of injury. Riding mowers present injury patterns and circumstances that are different than those reported for push mowers. Circumstances related to injuries and age groups affected were varied, making prevention of riding mower injuries challenging. APPLICATION/IMPACT: Findings support the need to increase awareness and/or change the design of riding mowers with respect to risk of rollover injuries.

Usefulness of extracorporeal membrane oxygenation using double roller pumps in a low body weight newborn: A novel strategy for mechanical circulatory support in an infant

Directory of Open Access Journals (Sweden)

Keisuke Nakanishi

2016-01-01

Full Text Available Extracorporeal membrane oxygenation (ECMO with a centrifugal pump requires a certain flow rate; therefore, its application for low body weight infants is frequently accompanied by oxygenator membrane malfunction and/or inadequate perfusion. To prevent low-flow associated complications, we report a case in which a novel system of dual roller pumps was used. A baby girl with a body mass index 0.25 m 2 , who experienced difficulty weaning from cardiopulmonary bypass after a Norwood-like operation, required an ECMO. Concerns for the tube lifespan reduction due to roller pump friction led to the use of a double roller pump circulation. The termination of ECMO during tube exchange is not needed, because circulation is maintained by another roller pump. The novel strategy of ECMO with double roller pumps will allow low perfusion rate to provide adequate circulatory support for low body weight patients.

Hacking Your Ride: Is Web 2.0 Creating Vulnerabilities To Surface Transportation

Science.gov (United States)

2016-09-01

NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release. Distribution is unlimited. HACKING YOUR RIDE...3. REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE HACKING YOUR RIDE: IS WEB 2.0 CREATING VULNERABILITIES TO SURFACE...Prescribed by ANSI Std. 239-18 ii THIS PAGE INTENTIONALLY LEFT BLANK iii Approved for public release. Distribution is unlimited. HACKING

Pin and roller attachment system for ceramic blades

Science.gov (United States)

Shaffer, J.E.

1995-07-25

In a turbine, a plurality of blades are attached to a turbine wheel by way of a plurality of joints which form a rolling contact between the blades and the turbine wheel. Each joint includes a pin and a pair of rollers to provide rolling contact between the pin and an adjacent pair of blades. Because of this rolling contact, high stress scuffing between the blades and the turbine wheel reduced, thereby inhibiting catastrophic failure of the blade joints. 3 figs.

Avoiding Electroerosion in roller bearings; Elektroerosion in Waelzlagern vermeiden

Energy Technology Data Exchange (ETDEWEB)

Preisinger, G.; Groeschl, M. [Inst. fuer Allgemeine Physik der TU Wien (Austria); Koettritsch, H. [SKF Oesterreich AG, Steyr (Austria)

2001-12-17

Roller bearings in electric motors and generators can be exposed to passage of current, which failes not only components, but also changes lubricants. The erosion can be avoided by isolation layers and optimized frequency converters. [German] Waelzlager in Elektromotoren und Generatoren koennen Stromdurchgang ausgesetzt sein, der nicht nur die Teile schaedigt, sondern auch den Schmierstoff veraendert. Die Schaeden sind nicht nur auf Metallteile begrenzt. Abhilfe bieten Isolationsschichten und optimierte Frequenzumrichter. (orig.)

Liikluseksperimendis edestas roller tsiklit ja teisi osalejaid : “2 vs 4″

Index Scriptorium Estoniae

2010-01-01

12. mail toimus Tallinnas keskkonnasõbraliku motonäituse MoMa raames eksperiment, milles osalesid jalgratas, elektriroller, roller, mootorratas ja auto. Marsruudil Miidurand-Nõmme üritati hommikuses liikluses välja selgitada, milline neist sõiduvahendest kõige edukamalt toime tuleb

The Theory of Dynamic Public Transit Priority with Dynamic Stochastic Park and Ride

Directory of Open Access Journals (Sweden)

Chengming Zhu

2014-01-01

Full Text Available Public transit priority is very important for relieving traffic congestion. The connotation of dynamic public transit priority and dynamic stochastic park and ride is presented. Based on the point that the travel cost of public transit is not higher than the travel cost of car, how to determine the level of dynamic public transit priority is discussed. The traffic organization method of dynamic public transit priority is introduced. For dynamic stochastic park and ride, layout principle, scale, and charging standard are discussed. Traveler acceptability is high through the analysis of questionnaire survey. Dynamic public transit priority with dynamic stochastic park and ride has application feasibility.

Calling, texting, and searching for information while riding a motorcycle: A study of university students in Vietnam.

Science.gov (United States)

Truong, Long T; De Gruyter, Chris; Nguyen, Hang T T

2017-08-18

The objective of this study was to investigate the prevalence of calling, texting, and searching for information while riding a motorcycle among university students and the influences of sociodemographic characteristics, social norms, and risk perceptions on these behaviors. Students at 2 university campuses in Hanoi and Ho Chi Minh City, the 2 largest cities in Vietnam, were invited to participate in an anonymous online survey. Data collection was conducted during March and May 2016. There were 741 respondents, of whom nearly 90% of students (665) were motorcycle riders. Overall prevalence of mobile phone use while riding is 80.9% (95% confidence interval [CI], 77.9-83.9%) with calling having a higher level of prevalence than texting or searching for information while riding: 74% (95% CI, 70.7-77.3%) vs. 51.7% (95% CI, 47.9-55.5%) and 49.9% (95% CI, 46.1-53.7%), respectively. Random parameter ordered probit modeling results indicate that mobile phone use while riding is associated with gender, motorcycle license duration, perceived crash risk, perceived risk of mobile phone snatching, and perceptions of friends' mobile phone use while riding. Mobile phone use while riding a motorcycle is highly prevalent among university students. Educational programs should focus on the crash and economic risk of all types of mobile phone use while riding, including calling, texting, and searching for information. In addition, they should consider targeting the influence of social norms and peers on mobile phone use while riding.

Roller and Centrifugal Pumps: A Retrospective Comparison of Bleeding Complications in Extracorporeal Membrane Oxygenation.

Science.gov (United States)

Halaweish, Ihab; Cole, Adam; Cooley, Elaine; Lynch, William R; Haft, Jonathan W

2015-01-01

Centrifugal pumps are increasingly used for extracorporeal membrane oxygenation (ECMO) rather than roller pumps. However, shear forces induced by these types of continuousflow pumps are associated with acquired von Willebrand factor deficiency and bleeding complications. This study was undertaken to compare adverse bleeding complications with the use of centrifugal and roller pumps in patients on prolonged ECMO support. The records of all adult ECMO patients from June 2002 to 2013 were retrospectively reviewed using the University of Michigan Health System database and the Extracorporeal Life Support Organization registry, focusing on patients supported for at least 5 days. Ninety-five ECMO patients met criteria for inclusion (48 roller vs. 47 centrifugal pump). Indications included pulmonary (79%), cardiac (15%), and extracorporeal cardiopulmonary resuscitation (6%), without significant difference between the two groups. Despite lower heparin anticoagulation (10.9 vs. 13.7 IU/kg/hr) with centrifugal pumps, there was a higher incidence of nonsurgical bleeding (gastrointestinal, pulmonary, and neurological) in centrifugal pump patients (26.1 vs. 9.0 events/1,000 patient-days, p = 0.024). In conclusion, in our historical comparison, despite reduced anticoagulation, ECMO support using centrifugal pumps was associated with a higher incidence of nonsurgical bleeding. The mechanisms behind this are multifactorial and require further investigation.

Visualizing asphalt roller trajectories in context: acquiring, processing, and representing sensor readings

NARCIS (Netherlands)

Vasenev, Alexandr

2015-01-01

The asphalt compaction process relies heavily on the skills and knowledge of roller operators who act alongside other stakeholders involved in asphalt paving. It is essential that these construction specialists: (1) are adequately informed about the initial temperature distribution of the asphalt

The Value of Optimization in Dynamic Ride-Sharing: a Simulation Study in Metro Atlanta

NARCIS (Netherlands)

N.A.H. Agatz (Niels); A. Erera (Alan); M.W.P. Savelsbergh (Martin); X. Wang (Xing)

2010-01-01

textabstractSmartphone technology enables dynamic ride-sharing systems that bring together people with similar itineraries and time schedules to share rides on short-notice. This paper considers the problem of matching drivers and riders in this dynamic setting. We develop optimization-based

High Capacity cylinder roller bearing; High Capacity Zylinderrollenlager. Ein vollrolliges Lager mit Kaefig

Energy Technology Data Exchange (ETDEWEB)

Reichert, J.; Baum, J. [SKF, Schweinfurt (Germany)

2007-07-15

The high capacity cylinder roller bearing is an example for continuous development of SKF products and does an effective contribution to increase operational safety and offers the possibility to reduce weight and compact design. (GL)

Spinal Cord Injuries in Wave-Riding Sports: The Influence of Environmental and Sport-Specific Factors.

Science.gov (United States)

Falconi, Audrey; Flick, David; Ferguson, Jason; Glorioso, John E

2016-01-01

Spinal cord injury is a nonfatal, catastrophic consequence of wave-riding sports. With surfing at the core, a multitude of activities have evolved that attempt to harness the power of ocean waves. The unique qualities of each wave-riding sport, in combination with the environmental factors of the ocean, define the risk for potential injuries. As wave-riding sports have become more advanced, athletes continue to push physical barriers. Taller waves are attempted while incorporating aerial maneuvers, all without protective equipment.

Kinematics of roller chain drives - Exact and approximate analysis

DEFF Research Database (Denmark)

Fuglede, Niels; Thomsen, Jon Juel

2016-01-01

An exact and approximate kinematic analysis of a roller chain drive modeled as a four-bar mechanism is presented. The span connects the sprockets such that they rotate in the same direction, and the sprocket size, number of teeth, and shaft center distance can be arbitrary. The driven sprocket...... to be very good agreement. All together this gives new insights into the characteristics of chain drive kinematics and the influence of main design parameters....

Free Riding Indexes for Ukrainian Economics Teachers.

Science.gov (United States)

McCorkle, Sarapage; Watts, Michael

1996-01-01

Reports on the adaptation and replication of Jane Leuthold's experiment concerning consumer choice, investments, and free riding indexes. A similar experiment, conducted in a Ukrainian classroom, produced similar results with a few notable exceptions. The exceptions reflected the Ukrainians' lack of familiarity with western economic thought. (MJP)

Calming the Waters or Riding the Waves?

DEFF Research Database (Denmark)

Rydén, Pernille; Kottika, Efthymia; Hossain, Muhammad Ismail

Traditional consumer anger management tends to be compromising rather than empowering the brand. This paper conceptualizes and provides a case example on how consumer empowerment and negative emotions can in fact create opportunities for companies to ride the waves of consumer anger in a way that...

Roller Testing to Mimic Damage of the ISS SARJ Ring and Durability Test to Simulate Fifteen Years of SARJ Operation Using the Damaged Surface

Science.gov (United States)

Krantz, Timothy L.; Elchert, Justin P.; DellaCorte, Christopher; Dube, Michael J.

2016-01-01

The International Space Station's starboard Solar Alpha Rotary Joint (SARJ) experienced a breakdown of the joint's race ring surface. The starboard SARJ mechanism was cleaned and lubricated with grease. To provide some guidance on the expected behavior of the damaged SARJ ring with continued operations, experiments were conducted using rollers and a vacuum roller test rig. The approach of the experimental work involved three main steps: (1) initiate damage using conditions representative of the SARJ with inadequate lubrication; (2) propagate the damage by operating the test rollers without lubrication; and (3) assess the durability of the roller by testing to simulate the equivalent of 15 years of SARJ operation on the damaged surface assuming adequate grease lubrication. During the rig testing, additional and/or replacement grease was introduced at regular intervals to maintain good lubrication in the rig. The damage to the nitride layer continued even after application of grease. The grease lubrication proved to be effective for limiting the value of the axial force that can be developed. Limiting the axial force on the SARJ mechanism is important since the larger the axial force the more concentrated the load pressure becomes on the blend-radius location on the SARJ roller. After the testing simulating 15 years of SARJ operations, the wear depths were the order of 0.2 mm for the nitrided 15-5 roller and the order of 0.06 mm for the mating 440C roller. Metallographic inspections were done to search for indications of impending fatigue or other fracture indications that might eventually propagate and cause structural failure. There were no indications or features found that could eventually compromise structural integrity.

Review of the system compatibility and ride-through options for AC and DC drives including multilevel inverters

Energy Technology Data Exchange (ETDEWEB)

Jouanne, A. von [Power Electronics Lab. - Elect. and Compt. Engineering Dept. - Oregon State Univ., Corvallis, OR (United States); Ben Banerjee, B. [Electric Power Research Inst. - Power Electronics, Energy Delivery, Palo Alto, CA (United States)

2000-07-01

Adjustable speed drive (ASD) compatibility and ride-through issues have caused increased concerns due to the susceptibility of AC and DC drives to power disturbances, and the costly results of process disruptions. These losses can be avoided for critical production processes by using ASDs with ride-through capabilities. This paper assesses industrial ride-through requirements and application issues for AC and DC drives, including medium voltage (2300/4160 V) multi-level inverter topologies. Ride-through alternatives are evaluated based on design, implementation and cost considerations in order to determine the most suitable solutions for various kVA ratings and time duration requirements. (orig.)

CircleRides: developing an older adult transportation application and evaluating feedback.

Science.gov (United States)

Heinz, Melinda; Kelly, Norene

2015-05-01

The purpose of the current study was to assess perceptions of CircleRides, a paper prototype of a service website designed to meet older adult transportation needs. Researchers used purposive sampling to conduct two focus groups comprised of older adults to obtain feedback on the CircleRides prototype at the beginning of its iterative design process. One focus group was conducted in a continuing care retirement community (n = 13) and the other in an independent living community for older adults (n = 11). The study assessed perceptions of the CircleRides prototype as well as self-reported older adult transportation preferences and needs. Three themes emerged from the data: (a) trust and concern, (b) socialization, and (c) flexibility and options. Researchers found that participants are interested in transportation options; however, concern exists about trusting a new system or prototype that has not established a reputation. Findings from the current study offer lessons learned for future iterations and for creating transportation prototypes for older adults. Copyright 2015, SLACK Incorporated.

Lake Robertson hydroelectric project. Construction of a roller compacted concrete dam

Energy Technology Data Exchange (ETDEWEB)

Labelle, M.; Robitaille, F. [Hydro-Quebec, Montreal, PQ (Canada)

1995-12-31

Construction of the Lake Robertson hydroelectric project on Quebec`s Lower North Shore was discussed in detail. The dam and powerhouse, located on the HaHa River, consists of a 134 m long concrete gravity dam, and a 21 MW powerhouse with two 69 kV transmission lines and four substations. The climate, terrain, and geography of the region, all of them characterized as severe, and the logistics of construction of the dam and power lines, aggravated by the isolation and severe conditions at the site, were described. The roller compacted concrete design and construction were noted, and justification for a concrete dam over an earth-fill dam was provided. Economics, properties, and composition of the roller compacted concrete (RCC) were examined, and control test results for the RCC concrete were provided. The use of RCC for the Lake Robertson development was described as successful in terms of the quality, watertightness, and completion time. The experience gained by the participants will make it possible to offer RCC as an alternative on various other projects. 2 figs.

Port Authority of Allegheny County Park and Rides

Data.gov (United States)

Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset includes the GIS shapefile for Port Authority of Allegheny County's Park and Ride facilities. This layer is updated annually or on an as-needed basis...

The two-dimensional cutting stock problem within the roller blind production process

NARCIS (Netherlands)

E.R. de Gelder; A.P.M. Wagelmans (Albert)

2007-01-01

textabstractIn this paper we consider a two-dimensional cutting stock problem encountered at a large manufacturer of window covering products. The problem occurs in the production process of made-to-measure roller blinds. We develop a solution method that takes into account the characteristics of

Research on the Effects of Hydropneumatic Parameters on Tracked Vehicle Ride Safety Based on Cosimulation

Directory of Open Access Journals (Sweden)

Shousong Han

2017-01-01

Full Text Available Ride safety of a tracked vehicle is the key focus of this research. The factors that affect the ride safety of a vehicle are analyzed and evaluation parameters with their criteria are proposed. A multibody cosimulation approach is used to investigate the effects of hydropneumatic parameters on the ride safety and aid with design optimization and tuning of the suspension system. Based on the cosimulation environment, the vehicle multibody dynamics (MBD model and the road model are developed using RecurDyn, which is linked to the hydropneumatic suspension model developed in Lab AMESim. Test verification of a single suspension unit is accomplished and the suspension parameters are implemented within the hydropneumatic model. Virtual tests on a G class road at different speeds are conducted. Effects of the accumulator charge pressure, damping diameter, and the track tensioning pressure on the ride safety are analyzed and quantified. This research shows that low accumulator charge pressure, improper damping diameter, and insufficient track tensioning pressure will deteriorate the ride safety. The results provide useful references for the optimal design and control of the parameters of a hydropneumatic suspension.

Development of an ultra-portable ride quality meter.

Science.gov (United States)

2012-12-01

FRAs Office of Research and Development has funded the development of an ultra-portable ride quality meter (UPRQM) under the Small Business and Innovative Research (SBIR) program. Track inspectors can use the UPRQM to locate segments of track that...

Preliminary evaluation of steel-roller round baler for woody biomass baling

Science.gov (United States)

B. J. Stokes; D. L. Sirois; S. L. Woodfin

1987-01-01

A round hay baler with little modification was used to bale small-diameter, crushed trees. The trees had been crushed using a series of compression rollers. Bale cores had to be developed by hand before the baler became self-feeding. Windrowed material was packed off the ground by the baler system after a core had been developed.

Leisure riding horses: research topics versus the needs of stakeholders.

Science.gov (United States)

Janczarek, Iwona; Wilk, Izabela

2017-07-01

Horses intended for leisure riding do not undergo any selection and most often retired sports horses or defective horses are chosen, as a low selling price determines their purchase by a leisure riding center. Unfortunately, horses bought at low prices usually have low utility value, are difficult to handle, require a special or individual approach and do not provide satisfaction in riding. However, neither modern horse breeding nor scientific research address the need to breed horses for leisure activities. There is no clear definition of a model leisure horse and criteria or information for its selection are not readily available in scientific publications. A wide spectrum of research methods may be used to evaluate various performance traits in horses intended for leisure activities. The fact that the population of recreational horses and their riders outnumber sporting horses should attract the special attention of scientific research. Their utility traits need to be determined with modern technology and methods in the same way they are for sporting horses. Such a system of evaluation would be very helpful for riders. © 2017 Japanese Society of Animal Science.

The influence of increased distal loading on metabolic cost, efficiency, and kinematics of roller ski skating.

Science.gov (United States)

Bolger, Conor M; Bessone, Veronica; Federolf, Peter; Ettema, Gertjan; Sandbakk, Øyvind

2018-01-01

The purpose of the present study was to examine the influence of increased loading of the roller ski on metabolic cost, gross efficiency, and kinematics of roller ski skating in steep and moderate terrain, while employing two incline-specific techniques. Ten nationally ranked male cross-country skiers were subjected to four 7-minute submaximal intervals, with 0, 0.5, 1.0, and 1.5 kg added beneath the roller-ski in a randomized order. This was done on two separate days, with the G2 skating at 12% incline and 7 km/h speed and G3 skating at 5% incline and 14 km/h speed, respectively. At 12% incline, there was a significant increase in metabolic rate and a decrease in gross efficiency with added weight (P0.05). No changes in cycle characteristics were observed between the different ski loadings at either incline, although the lateral and vertical displacements of the foot/skis were slightly altered at 12% incline with added weight. In conclusion, the present study demonstrates that increased loading of the ski increases the metabolic cost and reduces gross efficiency during steep uphill roller skiing in G2 skating, whereas no significant effect was revealed when skating on relatively flat terrain in G3. Cycle characteristics remained unchanged across conditions at both inclines, whereas small adjustments in the displacement of the foot coincided with the efficiency changes in uphill terrain. The increased RPE values with added ski-weight at both inclines indicates that other factors than those measured here could have influenced effort and/or fatigue when lifting a heavier ski.

Minimum Makespan Multi-vehicle Dial-a-Ride

DEFF Research Database (Denmark)

Gørtz, Inge Li; Nagarajan, Viswanath; Ravi, R.

2009-01-01

be left at intermediate vertices and transported by more than one vehicle, while being moved from source to destination. Approximation algorithms for the single vehicle Dial-a-Ride problem (q = 1) have been considered in [3,10]. Our main results are an O(log3n)-approximation algorithm for preemptive multi...

An optimum design on rollers containing the groove with changeable inner diameter based on response surface methodology

Directory of Open Access Journals (Sweden)

Xi Zhao

2016-05-01

Full Text Available In order to realize the precision plastic forming of the revolving body component with changeable wall thickness, a kind of roller containing grooves with changeable inner diameter is put forward, as the forming mould of the technology of rolling-extrusion. Specifically, first, the arc length of the groove in the roller is designed according to the prediction on the forward slip value during the process of forming, to make accurate control of the actual length of the forming segments; then, to obtain better parameters of the roller structure, a second-order response surface model combining finite element numerical simulation and response surface methodology was put forward, taking the factor of forming uniformity as evaluation index. The result of the experiment shows that, for the formed component, not only the size can meet the needs but also each mechanical property index can be greatly improved, which verify the rationality of the forward slip model and the structural parameter of the optimum model based on the response surface methodology.

Radiative inflation and dark energy RIDEs again after BICEP2

International Nuclear Information System (INIS)

Bari, Pasquale Di; King, Stephen F.; Merle, Alexander; Luhn, Christoph; Schmidt-May, Angnis

2014-01-01

Following the ground-breaking measurement of the tensor-to-scalar ratio r=0.20 +0.07 -0.05 by the BICEP2 collaboration, we perform a statistical analysis of a model that combines Radiative Inflation with Dark Energy (RIDE) based on the M 2 |Φ| 2 ln(|Φ| 2 /Λ 2 ) potential and compare its predictions to those based on the traditional chaotic inflation M 2 |Φ| 2 potential. We find a best-fit value in the RIDE model of r=0.18 as compared to r=0.17 in the chaotic model, with the spectral index being n S =0.96 in both models

Ride comfort enhancement in railway vehicle by the reduction of the car body structural flexural vibration

Science.gov (United States)

Dumitriu, M.

2017-08-01

The paper approaches the issue of reduction in the vertical bending vibrations of the railway vehicle carbody and the ride comfort enhancement at high velocities, starting from the prospect of isolating the vibrations by the best possible selection of the passive suspension damping in the vehicle. To this purpose, the examination falls on the influence of the vertical suspension damping upon the vibrations regime of the vehicle at the bending resonance frequency and upon the ride comfort. The results of the numerical simulations regarding the frequency response of the carbody acceleration and the comfort index will be therefore used. A value of the secondary suspension damping can be thus identified that will provide the best ride comfort performance. Similarly, the ride comfort can be increased by raising the primary suspension damping ratio.

Experimental studies in Ultrasonic Pulse Velocity of roller compacted concrete pavement containing fly ash and M-sand

Directory of Open Access Journals (Sweden)

S. Krishna Rao

2016-07-01

Full Text Available This paper presents the experimental investigation results of Ultrasonic Pulse Velocity (UPV tests conducted on roller compacted concrete pavement (RCCP material containing Class F fly ash of as mineral admixture. River sand, M-sand and combination of M-sand and River sand are used as fine aggregate in this experimental work. Three types of fly ash roller compacted concrete mixes are prepared using above three types of fine aggregates and they are designated as Series A (River sand, Series B (manufactured sand and Series C (combination of River sand and M-sand. In each series the fly ash content in place of cement is varied from 0% to 60%. In each series and for different ages of curing (i.e 3, 7, 28 and 90 days forty two cube specimens are cast and tested for compressive strength and UPV. The UPV results of fly ash containing roller compacted concrete pavement (FRCCP show lower values at all ages from 3 days to 90 days in comparison with control mix concrete (0% fly ash in all mixes. However, it is also observed that Series B and C mixes containing fly ash show better results in UPV values, compressive strength and Dynamic Elastic Modulus in comparison to Series A mixes with fly ash. Relationships between compressive strength of FRCCP and UPV and Dynamic Elastic Modulus are proposed for all series mixes. A new empirical equation is proposed to determine the Dynamic Elastic Modulus of FRCCP. Keywords: Compressive strength, Dynamic Elastic Modulus, Fly ash, Roller compacted concrete pavement, Ultrasonic Pulse Velocity

Demographic and psychological variables affecting test subject evaluations of ride quality

Science.gov (United States)

Duncan, N. C.; Conley, H. W.

1975-01-01

Ride-quality experiments similar in objectives, design, and procedure were conducted, one using the U.S. Air Force Total In-Flight Simulator and the other using the Langley Passenger Ride Quality Apparatus to provide the motion environments. Large samples (80 or more per experiment) of test subjects were recruited from the Tidewater Virginia area and asked to rate the comfort (on a 7-point scale) of random aircraft motion typical of that encountered during STOL flights. Test subject characteristics of age, sex, and previous flying history (number of previous airplane flights) were studied in a two by three by three factorial design. Correlations were computed between one dependent measure, the subject's mean comfort rating, and various demographic characteristics, attitudinal variables, and the scores on Spielberger's State-Trait Anxiety Inventory. An effect of sex was found in one of the studies. Males made higher (more uncomfortable) ratings of the ride than females. Age and number of previous flights were not significantly related to comfort ratings. No significant interactions between the variables of age, sex, or previous number of flights were observed.

U.S. gas outlook: A better year ahead

International Nuclear Information System (INIS)

Parent, L.

1996-01-01

Considering the mixed bag of factors affecting the US gas industry--restructuring, better prices, hopefully better margins, higher production, better drilling in some locations and some iffy stuff in the regulatory scene--the overall analysis is for a generally better year. After an extended period of low prices, the recent price surge is a welcome change. While the price roller coaster will probably continue, there should be, on the average, a $0.15--0.20 per Mcf improvement over 1995. Gas prices and the futures market are discussed further in the paper. Other conclusions developed in this article to support a basically optimistic outlook overview include: supply/demand; gas well drilling; entrance of electric power; integrated seamless pipeline networks; capacity turnback; and Canada/Mexico factors

Effect of health education on the riding habits of commercial motorcyclists in Uyo, southern Nigeria.

Science.gov (United States)

Johnson, O E; Owoaje, E T

2012-01-01

The increasing number of motorcyclists in Nigeria has led to a rise in poor road safety practices leading to increased rate of accidents. This study was conducted to implement and evaluate the effect of safety education on riding habits of motorcyclists in Uyo, Nigeria. The intervention study was conducted among commercial motorcyclists in Uyo with controls from another town in Akwa Ibom State. Baseline information was collected from both groups on their riding habits. Motorcyclists in Uyo were educated on appropriate road safety practices. Data was collected from both groups three months later and analysed using the Statistical Package for Social Sciences version 11. A total of 200 respondents participated in the study, 100 per group. At 3 months post-intervention, those riding when tired reduced in the intervention group from 69% at baseline to 42% (p Safety education improved many riding habits of motorcyclists in the intervention group. Road safety education is recommended for all motorcyclists to ensure safer road use.

Overuse Injuries Associated with Mountain Biking: Is Single-Speed Riding a Predisposing Factor?

Directory of Open Access Journals (Sweden)

Michael T. Lebec

2014-01-01

Full Text Available Though mountain bikers are at significant risk for overuse injury, there is minimal quality research describing this relationship. Single-speed mountain biking, in which participants pedal a bike with only a single gear, may place riders at even greater risk for overuse problems due to the disproportionate physical effort associated with this type of riding. The focus of this study was to provide additional perspective on overuse injuries sustained by mountain bikers and to determine if single-speed mountain biking places participants at greater risk for overuse conditions. Four hundred and four (404 mountain bikers were surveyed concerning overuse injuries sustained during the previous year. Findings indicate that 63% of respondents reported an overuse injury affecting at least one area with the most commonly reported areas being the lumbar spine, knees, hand/wrist, and cervical spine. Individuals riding single-speed mountain bikes did not have a higher incidence of overuse injuries than riders of multiple-geared bikes. However, respondents who split time between riding single-speed and multiple-geared bikes were significantly more likely to report an overuse syndrome than those only riding single-speed or multiple-geared bikes (p = 0.0104. This group of riders may be at greater risk for overuse injury due to excessive fatigue and poor biomechanics.

Influência das efemérides transmitidas e precisas no transporte de coordenadas

Directory of Open Access Journals (Sweden)

Felipe Mendes Suci

2010-01-01

Full Text Available O presente estudo descreve uma metodologia que dá suporte para a comparação dos resultados obtidos de processamentos com dados GPS utilizando-se de diferentes tipos de efemérides (transmitidas, ultrarrápidas, rápidas e finais. A metodologia proposta consta de diferentes etapas, que vão desde a obtenção dos dados RINEX (GPS e .sp3 (efemérides precisas nos sítios do IBGE e IGS respectivamente, passando pela atualização e transformação entre diferentes referenciais geodésicos (utilizando a Transformação Generalizada de Helmert, mudança entre sistemas cartesiano geocêntrico e geodésico local até a comparação das discrepâncias obtidas entre as coordenadas obtidas a partir do processamento (utilizando-se do aplicativo Trimble Geomatics Office - TGO e as coordenadas presentes nos descritivos. Os resultados mostraram que não há diferença relevante entre as soluções alcançadas com os diferentes tipos de efemérides precisas para as linhas de base analisadas nesse trabalho, porém, houve diferença considerável entre essas coordenadas e as obtidas com as efemérides transmitidas.

Study on the Effect of Steel Wheel and Ground on Single Steel Vibratory Roller

Science.gov (United States)

Li, Jiabo; You, Guanghui; Qiao, Jiabin; Ye, Min; Guo, Jin; Zhang, Hongyang

2018-03-01

In the compacting operation of single drum vibratory roller, the forces acting on the foundation of drum include the weight of the drum, the weight of the frame, the exciting force and so on. Based on the theoretical study of ground mechanics, this paper analyzes and calculates the forces acting on the steel wheel and the ground, and obtains the distribution of the laminar stress in the ground when the working plane vibrates. Derive the formula of dynamic compressive stress and static compressive stress in the foundation during vibration compaction. Through the compaction test of the soil trough of 20T single drum roller, the compressive stress data of the soil hydraulic field are obtained. The data of the dynamic compressive stress and the static compressive stress of each layer during the third compaction are obtained, and the theoretical research is verified.

Harvesting energy from the counterbalancing (weaving) movement in bicycle riding.

Science.gov (United States)

Yang, Yoonseok; Yeo, Jeongjin; Priya, Shashank

2012-01-01

Bicycles are known to be rich source of kinetic energy, some of which is available for harvesting during speedy and balanced maneuvers by the user. A conventional dynamo attached to the rim can generate a large amount of output power at an expense of extra energy input from the user. However, when applying energy conversion technology to human powered equipments, it is important to minimize the increase in extra muscular activity and to maximize the efficiency of human movements. This study proposes a novel energy harvesting methodology that utilizes lateral oscillation of bicycle frame (weaving) caused by user weight shifting movements in order to increase the pedaling force in uphill riding or during quick speed-up. Based on the 3D motion analysis, we designed and implemented the prototype of an electro-dynamic energy harvester that can be mounted on the bicycle's handlebar to collect energy from the side-to-side movement. The harvester was found to generate substantial electric output power of 6.6 mW from normal road riding. It was able to generate power even during uphill riding which has never been shown with other approaches. Moreover, harvesting of energy from weaving motion seems to increase the economy of cycling by helping efficient usage of human power.

Harvesting Energy from the Counterbalancing (Weaving Movement in Bicycle Riding

Directory of Open Access Journals (Sweden)

Shashank Priya

2012-07-01

Full Text Available Bicycles are known to be rich source of kinetic energy, some of which is available for harvesting during speedy and balanced maneuvers by the user. A conventional dynamo attached to the rim can generate a large amount of output power at an expense of extra energy input from the user. However, when applying energy conversion technology to human powered equipments, it is important to minimize the increase in extra muscular activity and to maximize the efficiency of human movements. This study proposes a novel energy harvesting methodology that utilizes lateral oscillation of bicycle frame (weaving caused by user weight shifting movements in order to increase the pedaling force in uphill riding or during quick speed-up. Based on the 3D motion analysis, we designed and implemented the prototype of an electro-dynamic energy harvester that can be mounted on the bicycle’s handlebar to collect energy from the side-to-side movement. The harvester was found to generate substantial electric output power of 6.6 mW from normal road riding. It was able to generate power even during uphill riding which has never been shown with other approaches. Moreover, harvesting of energy from weaving motion seems to increase the economy of cycling by helping efficient usage of human power.

Investigating possible use of roller bearings made of plastic in belt conveyor idlers

Energy Technology Data Exchange (ETDEWEB)

Grzeszek, A

1979-05-01

This paper presents results of laboratory and operational tests of roller bearings made of polyamide in belt conveyor idlers. During operational tests the conveyor was inclined to one side so the load on individual bearings varied and the bearings were also covered with dust and dirt. The tests show that the first failures of the plastic bearings took place after 3 months but some of the bearings were in operation one year without failures. All the failures were caused by wear of the bearing due to dust and dirt on their sliding surface. Increased friction resulted in higher temperatures which deformed the bearings. The tests showed that the bearings which were not dirty operated without failure. It is concluded that the plastic-made roller bearings cannot be used under conditions of brown coal surface mines as these mines are characterized by intense dustfall and by dirt which would increase friction in the bearings. (In Polish)

Planning, implementing and evaluating a social and communication skills course for riding instructors

OpenAIRE

Seefeld, Annika

2016-01-01

Social and emotional skills are very important for effective coaching. As research in this field is still very limited, the purpose of this study was to plan, implement and evaluate a course teaching social and emotional skills to riding instructors. The objective of this research project was to analyse the usefulness and feasibility of a social and communication skills course for riding instructors. The present research study is an educational action research case study approa...

Rereading "The Jack-Roller:" Hidden Histories in Sociology and Social Work

Science.gov (United States)

Shaw, Ian

2009-01-01

I revisit one of the iconic Chicago School studies, Clifford Shaw's "The Jack-Roller". A naive reading of Shaw's book leaves the reader with a sense of having been inducted into a melange of what we now know as "sociology" and "social work," but which to Shaw seems a coherent stance. I suggest that this is close to the heart of how things were,…

Riding Bikes: A Pastime for Every Child

Science.gov (United States)

Mathias, Michelle

2011-01-01

People have heard the expression "It's as easy as riding a bike." But the idea of a child with special needs balancing, steering, and pedaling a bike can seem out of reach for some; especially when he may be unable to walk unaided or hold his head up without support. Physical capabilities or stamina need not keep a child from this pleasurable…

Out-of-plane stability of roller bent steel arches – an experimental investigation

NARCIS (Netherlands)

La Poutre, D.B.; Spoorenberg, R.C.; Snijder, H.H.; Hoenderkamp, J.C.D.

2013-01-01

This paper presents an experimental investigation of the elastic-plastic out-of-plane buckling response of roller bent circular steel arches subjected to a single force applied to the crown. The experiments are used to validate a finite element model described in a related paper. A series of 15

A General Case to Determine Dimensions and Their Tolerance Zones for the Thread Parts of Epicyclic Roller-Screw Mechanisms

Directory of Open Access Journals (Sweden)

D. S. Blinov

2017-01-01

Full Text Available The most important trend in the development of aerospace industry is to increase load capacity of mechanisms, assemblies, and parts without increasing their size and weight. The above is also true for widely used in aircrafts and the most promising up to date Epicyclic Roller-Screw Mechanisms (ERSM that convert rotational movement into translational one. Previously (in the article, it was proposed to increase the load capacity (approximately by 15% through reduction of included angle of ERSM threaded parts from 90° to 70°.However, such improvement of ERSM will change dimensions of the mechanism parts and its parameters and characteristics (efficiency factor, position of initial point of contact of the conjugated thread turns and parameters of their contact interaction, as well as kinematic parameters, which will require additional studies. If we take into account the priority of these studies, then surely we must begin with development of technique to determine dimensions of the ERSM main parts and their tolerance zones because we need drawings to manufacture and test the upgraded ERSM. We have developed a technique to calculate dimensions of the main parts of ERSM and associated tolerance zones that takes in to account the change of included angle of threaded parts of the mechanism and radius of circular arc according to which roller thread profile has been fulfilled. So the proposed technique is the general one in comparison with the previous ones.This technique uses various conditions and equations to determine dimensions of parts and associated tolerance zones. For example, a nut encircles a screw with rollers, and their dimensions form a closed dimension chain, in which the dimensions and associated tolerances must be such as to ensure ERSM assembling, on the one hand, and, on the other hand the backlash of the mechanism should be minimal to ensure high load capacity, kinematic accuracy, and rigidity of ERSM. We used the following

Distributed Low Voltage Ride-Through Operation of Power Converters in Grid-Connected Microgrids under Voltage Sags

DEFF Research Database (Denmark)

Zhao, Xin; Meng, Lexuan; Dragicevic, Tomislav

2015-01-01

it can make the MG a contributor in smooth ride through the faults. In this paper, a reactive power support strategy using droop controlled converters is proposed to aid MG riding through three phase symmetrical voltage sags. In such a case, the MGs should inject reactive power to the grid to boost...... the voltage in all phases at AC common bus. However, since the line admittances from each converter to point of common coupling (PCC) are not identical, the injected reactive power may not be equally shared. In order to achieve low voltage ride through (LVRT) capability along with a good power sharing...

Fault ride-through and voltage support of permanent magnet synchronous generator wind turbines

Energy Technology Data Exchange (ETDEWEB)

Michalke, G.; Hartkopf, T. [Darmstadt Technical Univ., Dept. of Renewable Energies (Germany); Hansen, A.D. [Risoe National Lab., DTU, Wind Energy Dept. (Denmark)

2007-11-15

This paper presents a control strategy of direct driven multipole PMSG wind turbines, which enhances the fault ride-through and voltage support capability of such wind turbines during grid faults. A dynamic simulation model of the turbine is implemented in the simulation software DIgSILENT. Simulation results approve the effectiveness of the developed control strategy. It is shown that PMSG wind turbines equipped with such control even enable nearby connected conventional wind turbines to ride-through grid faults. (au)

The Theory of Dynamic Public Transit Priority with Dynamic Stochastic Park and Ride

OpenAIRE

Zhu, Chengming; Chen, Yanyan; Ma, Changxi

2014-01-01

Public transit priority is very important for relieving traffic congestion. The connotation of dynamic public transit priority and dynamic stochastic park and ride is presented. Based on the point that the travel cost of public transit is not higher than the travel cost of car, how to determine the level of dynamic public transit priority is discussed. The traffic organization method of dynamic public transit priority is introduced. For dynamic stochastic park and ride, layout principle, scal...

A new pneumatic suspension system with independent stiffness and ride height tuning capabilities

Science.gov (United States)

Yin, Zhihong; Khajepour, Amir; Cao, Dongpu; Ebrahimi, Babak; Guo, Konghui

2012-12-01

This paper introduces a new pneumatic spring for vehicle suspension systems, allowing independent tuning of stiffness and ride height according to different vehicle operating conditions and driver preferences. The proposed pneumatic spring comprises a double-acting pneumatic cylinder, two accumulators and a tuning subsystem. This paper presents a detailed description of the pneumatic spring and its working principle. The mathematical model is established based on principles of thermo and fluid dynamics. An experimental setup has been designed and fabricated for testing and evaluating the proposed pneumatic spring. The analytical and experimental results confirm the capability of the new pneumatic spring system for independent tuning of stiffness and ride height. The mathematical model is verified and the capabilities of the pneumatic spring are further proved. It is concluded that this new pneumatic spring provides a more flexible suspension design alternative for meeting various conflicting suspension requirements for ride comfort and performance.

Long-Life, Oil-Free Polymeric, Multi-Roller Traction Drives for Planetary Vehicle Surface Exploration, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Multi-roller traction drives have several advantages relative to geared units for aerospace and commercial drive applications. Among these are zero backlash, low...

Risky riding behavior on two wheels: the role of cognitive, social, and personality variables among young adolescents.

Science.gov (United States)

Falco, Alessandra; Piccirelli, Alessandra; Girardi, Damiano; Dal Corso, Laura; De Carlo, Nicola A

2013-09-01

The main objective of this study was to analyze and estimate the relations between risky riding behaviors and some personality and sociocognitive variables through structural equation modeling. We focused on two-wheel riding behavior among a sample of 1,028 Italian adolescents at their first driving experience. The main findings confirmed the role of personality in influencing riding behavior directly as well as indirectly through risk perception. In particular, risk perception was a significant mediator between personality, social norm, and riding behavior. The significant relations that emerged in the general sample were further confirmed in the two specific sub-samples of males and females. In terms of social marketing and educational communication, it may consequently be advisable to proceed in an integrated and coordinated manner at both the cognitive and social level, taking into account some "dispositions to risk" related to personality. The integrated and coordinated action on different levels--cognitive, social, and personality--may therefore allow more effective and significant results in reducing those risky riding behaviors that often underlie young two-wheel riders' higher involvement in traffic accidents. Copyright © 2013 National Safety Council and Elsevier Ltd. All rights reserved.

Emergency transfer tube closure and process for sealing transfer tube under emergency conditions

International Nuclear Information System (INIS)

Hardin, R.T. Jr.; Marshall, J.R.

1987-01-01

In a nuclear fuel reactor well that includes a transfer tube projecting outwardly from wall thereof, the transfer tube is described having a first closure assembly. The transfer tube has a circumferential flange extending outwardly laterally therefrom, an emergency transfer tube closure therefor comprising; a pair of elongated, vertically-extending U-shaped guides, one U-shaped guide disposed laterally on each side of the transfer tube, each of the U-shaped guides comprising a base and laterally extending flanges thereon, the U-shaped guides having their open ends facing each other, a closure plate, having a surface facing the circumferential flange greater in area than the area circumscribed by the outer circumference of the circumferential flange, vertically disposed the U-shaped guides, the closure plate normally being disposed in a vertical plane just slightly in front of the vertical plane of the circumferential flange, two pairs of rollers, one pair of which is rotatably mounted on each side of the closure plate adjacent the U-shaped guides, riding on the inner portion of each of the flanges of each of the U-shaped guides. Each of the U-shaped guides is provided with a pair of spatially disposed openings on a flange thereof adjacent the wall of the nuclear fuel reactor well, each of the pairs of openings being disposed on each of the U-shaped guides a distance equal to the distance between the center lines of the corresponding pair of rollers riding within the U-shaped guides, each of the openings being sufficiently large to receive a corresponding roller of the pairs of rollers in the U-shaped guides. The openings is shaped on the flanges of the U-shaped guides so that when the pairs of rollers are disposed therein, the face of the closure plate will be in sealing engagement with the circumferential flange of the transfer tube

mitigating mitigating free riding in peer-to-peer networks

African Journals Online (AJOL)

eobe

The performance of peer-to-peer systems is based on the quality and quantity of resource contributions from peer systems ... riding [3]. There are several measurement studies ...... J. S. Hua, D. C. Huang, S M Yen, and C. W. Chena, “A dynamic.

The selection of flying roller as an effort to increase the power of scooter-matic as the main power of centrifugal pump for fire fighter motor cycle

Science.gov (United States)

Hadi Sutrisno, Himawan

2018-03-01

In densely populated settlements, fires often occur and cause losses. In some instances, the process of the occurrence of fires takes place so quickly that to reduce and avoid the occurrence of a fire disaster effort is required in accordance with the existing environmental condition. Fire fighter motorcycle by using motorcycle scooter-matic is considered suitable as one alternative to combating fire hazard in densely populated residential settlements. The use of motorcycle engines as the driving force of the pump often leads to unstable and not optimum power. Thus, the water spray on the centrifugal pump also becomes not maximum. To increase the engine power at scooter-matic engine idle rotation (700-2000 rpm), then the flying roller replacement with certain mass weight becomes an option. By selecting a 10 to 14 gram flying roller mass, the power analysis using a dynotest engine produces several variations. Of the calculation, the mass of a 14 gram flying roller provides a significant increase in motor power on the upper rotation. Meanwhile, on the lower power rotation using a flying roller with a mass of 10 grams provides an increase in power compared to a standard flying roller on a scooter matic motor engine. As a reference to the use of scooter-matic motor power as the pump power, the result of use of the flying roller with a mass of 10 grams becomes the best option.

Ride control of surface effect ships using distributed control

Directory of Open Access Journals (Sweden)

Asgeir J. Sørensen

1994-04-01

Full Text Available A ride control system for active damping of heave and pitch accelerations of Surface Effect Ships (SES is presented. It is demonstrated that distributed effects that are due to a spatially varying pressure in the air cushion result in significant vertical vibrations in low and moderate sea states. In order to achieve a high quality human comfort and crew workability it is necessary to reduce these vibrations using a control system which accounts for distributed effects due to spatial pressure variations in the air cushion. A mathematical model of the process is presented, and collocated sensor and actuator pairs are used. The process stability is ensured using a controller with appropriate passivity properties. Sensor and actuator location is also discussed. The performance of the ride control system is shown by power spectra of the vertical accelerations obtained from full scale experiments with a 35 m SES.

Riding Pontic--Aesthetic Journey Aesthetic Goal.

Science.gov (United States)

Rohilla, Byajit Kumar; Choudhary, Shweta; Manisha, Kukreja; Walia, Pawanjit Singh; Nafria, Anil

2015-01-01

The increasing concern for esthetics during the orthodontic treatment can be measured by the increasing popularity ofaesthetic brackets, lingual technique, smaller sized metal brackets, and clear alignment therapy. Many clients, especially adolescents, are self-conscious about their appearance in social and professional situations, and they refuse to tolerate the inevitable "black holes" of edentulous spaces during orthodontic treatment. This article describes the use, fabrication, modifications, and shortcomings of riding pontics; and illustrates how their use provides aesthetic, psychological and functional benefits.

An Analysis of US Emergency Department Visits From Falls From Skiing, Snowboarding, Skateboarding, Roller-Skating, and Using Nonmotorized Scooters.

Science.gov (United States)

Nathanson, Brian H; Ribeiro, Kara; Henneman, Philip L

2016-07-01

We analyzed the US incidence of emergency department (ED) visits and hospitalizations for falls from skiing, snowboarding, skateboarding, roller-skating, and nonmotorized scooters in 2011. The outcome was hospital admission from the ED. The primary analysis compared pediatric patients aged 1 to 17 years to adults aged 18 to 44 years. The analysis used ICD-9 E-codes E885.0 to E885.4 using discharge data from the Nationwide Emergency Department Sample, Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality. Approximately 214 000 ED visits met study criteria. Skiing injuries had the highest percentage of hospitalizations (3.30% in pediatric patients and 6.65% in adults 18-44 years old). Skateboard and snowboard injuries were more likely to require hospitalization than roller skating injuries in pediatric patients (odds ratio = 2.42; 95% CI = 2.14-2.75 and odds ratio = 1.83; 95% CI =1.55-2.15, respectively). In contrast, skateboard and snowboard injuries were less severe than roller-skating injuries in adults. © The Author(s) 2015.

Ride performance of a high speed rail vehicle using controlled semi active suspension system

Science.gov (United States)

Sharma, Sunil Kumar; Kumar, Anil

2017-05-01

The rail-wheel interaction in a rail vehicle running at high speed results in large amplitude vibration of carbody that deteriorates the ride comfort of travellers. The role of suspension system is crucial to provide an acceptable level of ride performance. In this context, an existing rail vehicle is modelled in vertical, pitch and roll motions of carbody and bogies. Additionally, nonlinear stiffness and damping parameters of passive suspension system are defined based on experimental data. In the secondary vertical suspension system, a magneto-rheological (MR) damper is included to improve the ride quality and comfort. The parameters of MR damper depend on the current, amplitude and frequency of excitations. At different running speeds, three semi-active suspension strategies with MR damper are analysed for periodic track irregularity and the resulting performance indices are juxtaposed with the nonlinear passive suspension system. The disturbance rejection and force tracking damper controller algorithms are applied to control the desired force of MR damper. This study reveals that the vertical vibrations of a vehicle can be reduced significantly by using the proposed semi-active suspension strategies. Moreover, it naturally results in improved ride quality and passenger’s comfort in comparison to the existing passive system.

Free riding and the provision of candy bars

NARCIS (Netherlands)

Haan, M.A.; Kooreman, P.

A wealth of experimental literature studies the effect of repetition and group size on the extent of free riding in the provision of public goods. In this paper, we use data from honor systems for candy bars in 166 firms to test whether such effects can be found outside the laboratory. We find that

Radiometric and ultrasonic testing of vibrating roller compacting effects

International Nuclear Information System (INIS)

Prikryl, F.; Habarta, J.; Kovarikova, E.

1977-01-01

A hole was filled with two layers of concrete mixture. Each layer was compacted using a Dynapac CA 25 vibrating roller 10,000 kg in weight, operating with a frequency of 30 Hz. A concrete block thus produced had dimensions of 11.0x2.5 m and a height of 1.6 m. After the concrete block hardening (roughly 120 days) drill cores were bored and bulk density was determined using nondestructive methods. Bulk density determination of the concrete between the drill cores was conducted using a 137 Cs emitter of an activity of 89 GBq, a FHZ-88b Geiger-Mueller counter was used as the detector. The emitter and detector were placed to touch the bore wall and were lowered to different depths in 10 cm increments. 10 count rate values were measured in each depth. The measurement time was chosen such that the decay statistical error did not exceed 1;. Bulk density of the individual segments of the drill cores was determined using 60 Co of an activitBy of 55 Mq as the radiation source and a TESLA 20/100 GWl GM counter as the detector. The detector operating voltage was 1240 V. Ultrasonic measurements were conducted using the USME-5 instrument. The measured bulk density values show that the compacting of a concrete layer 80 cm in thickness using a vibrating roller is sufficiently efficient. Both nondestructive methods were well proven, the results show that bulk density values in different depths differ due to concrete moisture content. (J.P.)

A novel "hitch-and-ride" deep biliary cannulation method during rendezvous endoscopic ultrasound-guided ERCP technique.

Science.gov (United States)

Nakai, Yousuke; Isayama, Hiroyuki; Matsubara, Saburo; Kogure, Hirofumi; Mizuno, Suguru; Hamada, Tsuyoshi; Takahara, Naminatsu; Nakamura, Tomoka; Sato, Tatsuya; Takeda, Tsuyoshi; Hakuta, Ryunosuke; Ishigaki, Kazunaga; Saito, Kei; Tada, Minoru; Koike, Kazuhiko

2017-10-01

Background and study aim Endoscopic ultrasound-guided rendezvous (EUS-RV) is increasingly reported as a treatment option after failed endoscopic retrograde cholangiopancreatography. We developed a novel "hitch-and-ride" catheter for biliary cannulation to reduce the risk of guidewire loss during EUS-RV. Patients and methods We retrospectively evaluated safety and technical success of EUS-RV between June 2011 and May 2016. Biliary cannulation during EUS-RV using three methods - over-the-wire, along-the-wire, and hitch-and-ride - were compared. Results A total of 30 EUS-RVs were attempted and the technical success rate was 93.3 %, with two failures (one bile duct puncture and one guidewire insertion). After 28 cases of successful guidewire passage, cannulation was attempted by the over-the-wire (n = 13), along-the-wire (n = 4) or hitch-and-ride (n = 11) method. Only the hitch-and-ride method achieved biliary cannulation without guidewire loss or conversion to the other methods. Time to cannulation was shorter with the hitch-and-ride method (4 minutes) than with over-the-wire and along-the-wire methods (9 and 13 minutes, respectively). The adverse event rate of EUS-RV was 23.3 %. Conclusion A novel hitch-and-ride catheter was feasible for biliary cannulation after EUS-RV. © Georg Thieme Verlag KG Stuttgart · New York.

Significant changes in the skin microbiome mediated by the sport of roller derby

Directory of Open Access Journals (Sweden)

James F. Meadow

2013-03-01

Full Text Available Diverse bacterial communities live on and in human skin. These complex communities vary by skin location on the body, over time, between individuals, and between geographic regions. Culture-based studies have shown that human to human and human to surface contact mediates the dispersal of pathogens, yet little is currently known about the drivers of bacterial community assembly patterns on human skin. We hypothesized that participation in a sport involving skin to skin contact would result in detectable shifts in skin bacterial community composition. We conducted a study during a flat track roller derby tournament, and found that teammates shared distinct skin microbial communities before and after playing against another team, but that opposing teams’ bacterial communities converged during the course of a roller derby bout. Our results are consistent with the hypothesis that the human skin microbiome shifts in composition during activities involving human to human contact, and that contact sports provide an ideal setting in which to evaluate dispersal of microorganisms between people.

Tonopah Test Range Air Monitoring: CY2016 Meteorological, Radiological, and Wind Transported Particulate Observations

Energy Technology Data Exchange (ETDEWEB)

Chapman, Jenny [Desert Research Inst. (DRI), Las Vegas, NV (United States); Nikolich, George [Desert Research Inst. (DRI), Las Vegas, NV (United States); Shadel, Craig [Desert Research Inst. (DRI), Las Vegas, NV (United States); McCurdy, Greg [Desert Research Inst. (DRI), Las Vegas, NV (United States); Etyemezian, Vicken [Desert Research Inst. (DRI), Las Vegas, NV (United States); Miller, Julianne J [Desert Research Inst. (DRI), Las Vegas, NV (United States); Mizell, Steve [Desert Research Inst. (DRI), Las Vegas, NV (United States)

2017-10-01

In 1963, the U.S. Department of Energy (DOE) (formerly the Atomic Energy Commission [AEC]), implemented Operation Roller Coaster on the Tonopah Test Range (TTR) and an adjacent area of the Nevada Test and Training Range (NTTR) (formerly the Nellis Air Force Range). This operation resulted in radionuclide-contaminated soils at the Clean Slate I, II, and III sites. This report documents observations made during ongoing monitoring of radiological, meteorological, and dust conditions at stations installed adjacent to Clean Slate I and Clean Slate III, and at the TTR Sandia National Laboratories (SNL) Range Operations Control (ROC) center. The primary objective of the monitoring effort is to determine if wind blowing across the Clean Slate sites is transporting particles of radionuclide-contaminated soil beyond the physical and administrative boundaries of the sites.

Mitigating Free Riding in Peer-To-Peer Networks: Game Theory ...

African Journals Online (AJOL)

Mitigating Free Riding in Peer-To-Peer Networks: Game Theory Approach. ... In this paper, we model the interactions between peers as a modified gift giving game and proposed an utility exchange incentive ... AJOL African Journals Online.

The social context of motorcycle riding and the key determinants influencing rider behavior: a qualitative investigation.

Science.gov (United States)

Tunnicliff, Deborah; Watson, Barry; White, Katherine M; Lewis, Ioni; Wishart, Darren

2011-08-01

Given the increasing popularity of motorcycle riding and heightened risk of injury or death associated with being a rider, this study explored rider behavior as a determinant of rider safety and, in particular, key beliefs and motivations that influence such behavior. To enhance the effectiveness of future education and training interventions, it is important to understand riders' own views about what influences how they ride. Specifically, this study sought to identify key determinants of riders' behaviors in relation to the social context of riding, including social and identity-related influences relating to the group (group norms and group identity) as well as the self (moral/personal norm and self-identity). Qualitative research was undertaken via group discussions with motorcycle riders (n = 41). The findings revealed that those in the group with which one rides represent an important source of social influence. Also, the motorcyclist (group) identity was associated with a range of beliefs, expectations, and behaviors considered to be normative. Exploration of the construct of personal norm revealed that riders were most cognizant of the "wrong things to do" when riding; among those issues raised was the importance of protective clothing (albeit for the protection of others and, in particular, pillion passengers). Finally, self-identity as a motorcyclist appeared to be important to a rider's self-concept and was likely to influence on-road behavior. Overall, the insight provided by the current study may facilitate the development of interventions including rider training as well as public education and mass media messages. The findings suggest that these interventions should incorporate factors associated with the social nature of riding in order to best align it with some of the key beliefs and motivations underpinning riders' on-road behaviors.

Epidemiological pattern of motorcycle injuries with focus on riding purpose: Experience from a middle-income country

Directory of Open Access Journals (Sweden)

leili Abedi

2015-08-01

Full Text Available Introduction: Road traffic injuries are the eighth leading cause of death worldwide which usually occurs among people aged between15-29 years. In most LAMICs, half of fatal road traffic injuries occur among motorcyclists, which little is known about purpose of riding among motorcycle riders. Objectives: To map out epidemiological aspects of motorcycle traffic injuries with a focus on purpose of riding among victims admitted to referral centers, Tabriz, Iran. Materials/Patients and Methods: A descriptive study was carried out on 200 motorcycle traumatic patients admitted to Shohada and Imam Reza trauma centers in Tabriz((because these two hospitals are referral for trauma in East Azarbyjan Province, Iran from April till November 2013. A questionnaire was filled out through face to face interview for all subjects. Statistical analysis was done using Stata version 11. Results: All subjects were male with mean age of 29 years old. Among injured riders, 70% and 22% of them used helmet and had a riding license, respectively. About 23% of motorcycle riders stated that their main purpose of motorcycle riding was only for fun. Among motorcycle riders who used the motorcycle for fun purposes, the rate of helmet wearing was 43.5% versus 78% among those riding for other purposes (P 0.05; Odd ratio=1. 56, 95% CI: 0. 67-3.4. Crashes have happened more in the summer and during the afternoon times. Conclusion: Motorcyclists who rode motorcycles for fun and amusement, not having rider licenses and helmets wearing were less than other motorcycle riders. Since motorcyclists are mainly young, the rate of risky behavior in this group is higher. Therefore, it is suggested that young motorcycle riders who ride for fun, needs the priority for safety promotion intervention.

Parathyroid adenoma apoplexy as a temporary solution of primary hyperparathyroidism: a case report

Directory of Open Access Journals (Sweden)

Pereira Francisco A

2007-11-01

Full Text Available Abstract Introduction The natural history of patients with spontaneous parathyroid necrosis is unknown. In this case report we describe the clinical course, laboratory, radiographic, bone densitometry tests, parathyroid ultrasonography and scintigraphy examinations of a patient performed over a period of eight years after she first presented with a sudden episode of spontaneous resolution of primary hyperparathyroidism (PHPT. Case presentation A 24-year-old woman with a clinical history and laboratory and radiographic tests compatible with PHPT suffered a sudden episode of cervical pain and presented with clinical evidence of hypocalcemia. Biopsy of a cervical nodule revealed necrotic material compatible with ischemia of the parathyroid. The follow-up of the patient presented four distinct phases: the first, which lasted two years, was compatible with a period of bone hunger during which it was necessary to introduce calcitriol and calcium carbonate. During this period, the patient showed bone mass gain. The second phase was characterized by normalization of calcium and parathyroid hormone levels and its end was difficult to define. During the third phase there was a recurrence of hypercalcemia associated with elevated parathyroid hormone (PTH levels and loss of bone mass. The last phase corresponded to the interval after parathyroidectomy, which was characterized by normalization of serum levels of calcium and PTH, as well as bone mass gain. Conclusion This case report indicates that spontaneous resolution of PHPT by adenoma necrosis is potentially temporary. Thus, in cases in which a conservative approach is chosen, clinical and laboratory follow-up is indispensable. Bone mass measurement is a useful tool in the follow-up of these cases. However, this option exposes the patient to a potential roller-coaster ride of bone mass gain and loss, whose long term consequences are still unknown.

Power-Up: Exploration and Play in a Novel Modified Ride-On Car for Standing.

Science.gov (United States)

Logan, Samuel W; Lobo, Michele A; Feldner, Heather A; Schreiber, Melynda; MacDonald, Megan; Winden, Haylee N; Stoner, Tracy; Galloway, James Cole

2017-01-01

The purpose of this study was to compare the physical activity and play behaviors of preschoolers without disabilities and 1 preschooler with physical disability. Participants were 42 preschoolers without disabilities and 1 preschooler with physical disability (Child A). Child A used either crutches or a modified ride-on car while in the gymnasium and playground. In the gymnasium, Child A engaged in less solitary play and more parallel play while using the modified ride-on car compared with crutches. On the playground, Child A engaged in more sitting and less running while using crutches compared with preschoolers without disabilities. On the playground, Child A engaged in more peer interaction and less teacher interaction when using the modified ride-on car compared with crutches. For children with disabilities who may use assistive devices, clinicians, families, and teachers are encouraged to embrace a "right device, right time, right place" approach.

Hot Ductility Behavior of an 8 Pct Cr Roller Steel

Science.gov (United States)

Wang, Zhenhua; Sun, Shuhua; Shi, Zhongping; Wang, Bo; Fu, Wantang

2015-04-01

The hot ductility of an 8 pct Cr roller steel was determined between 1173 K and 1473 K (900 °C and 1200 °C) at strain rates of 0.01 to 10 s-1 through tensile testing. The fracture morphology was observed using scanning electron microscopy, and the microstructure was examined through optical microscopy and transmission electron microscopy. The dependence of the hot ductility behavior on the deformation conditions, grain size, and precipitation was analyzed. The relationship between the reduction in area and the natural logarithm of the Zener-Hollomon parameter (ln Z) was found to be a second-order polynomial. When ln Z was greater than 40 s-1, the hot ductility was poor and fracture was mainly caused by incompatible deformation between the grains. When ln Z was between 32 and 40 s-1, the hot ductility was excellent and the main fracture mechanism was void linking. When ln Z was below 32 s-1, the hot ductility was poor and fracture was mainly caused by grain boundary sliding. A fine grain structure is beneficial for homogenous deformation and dynamic recrystallization, which induces better hot ductility. The effect of M7C3 carbide particles dispersed in the matrix on the hot ductility was small. The grain growth kinetics in the 8 pct Cr steel were obtained between 1373 K and 1473 K (1100 °C and 1200 °C). Finally, optimized preheating and forging procedures for 8 pct Cr steel rollers are provided.

Fault Ride Though Control of Photovoltaic Grid-connected Inverter with Current-limited Capability under Offshore Unbalanced Voltage Conditions

DEFF Research Database (Denmark)

Liu, Wenzhao; Guo, Xiaoqiang; Savaghebi, Mehdi

2016-01-01

The photovoltaic (PV) inverter installed on board experiences the excessive current stress in case of the offshore unbalanced voltage fault ride through (FRT), which significantly affects the operation reliability of the power supply system. In order to solve the problem, the inherent mechanism...... of the excessive current phenomenon with the conventional fault ride through control is discussed. The quantitative analysis of the current peak value is conducted and a new current-limiting control strategy is proposed to achieve the flexible power control and successful fault ride through in a safe current...

Optimizing itineraries in public transportation with walks between rides

NARCIS (Netherlands)

de Jonge, Bram; Teunter, Ruud H.

We study the problem of finding an optimal itinerary to travel from a starting location to a destination location using public transport, where we allow travelers to alternate rides with (short) walks. The main difference with previous research is that we take all possible walks that a traveler can

Psyclones: a roller coaster of life? Hidden synthetic cannabinoids and stimulants in apparently harmless products.

Science.gov (United States)

Santacroce, Rita; Corazza, Ornella; Martinotti, Giovanni; Bersani, Francesco Saverio; Valeriani, Giuseppe; Di Giannantonio, Massimo

2015-07-01

The urge to gain information on a new drug marketed online as 'Psyclone' has emerged after the death of a 38-year-old man in Bolton (UK). The fatality appeared to be a consequence of smoking this psychoactive product. From October to December 2013, qualitative searches of the Web have been carried out in English and Italian, using the keywords 'Psyclone', 'Psyclone legal high', 'Psyclone incense' and 'Psyclone research chemical' on the Google search engine and on the database provided by the Global Public Health Intelligence Network. Our research highlighted the existence of two psychoactive products labelled as Psyclone but with different contents and packaging: a herbal blend containing two synthetic cannabinoids (AKB-48 and 5f-PB-22) and a research chemical containing 50% ethylphenidate, 30% caffeine and 20% lidocaine. Desired and side effects of both compounds are explored in the paper. Being sold as a legal product, Psyclone may appeal to recreational users, who remain unaware of its real content. This is a serious public health threat, which may lead to acute intoxications and fatalities. Further studies in the field, including Internet monitoring, are therefore required. Copyright © 2015 John Wiley & Sons, Ltd.

Free Riding or Trust?

DEFF Research Database (Denmark)

Svendsen, Gert Tinggaard; Nilsson, Jerker

2011-01-01

It is often observed that members have little interest in monitoring their cooperatives. One explanation is that the members are free-riders, hoping that others will perform the task. Another explanation is that the weak member interest is a consequence of members having trust in the leadership....... These competing explanations refer to the theory of collective action and the social capital paradigm, respectively, and may be linked to the classical Gesellschaft and Gemeinschaft concepts. Hence, one may expect free-rider behavior when conditions of Gesellschaft exist and trustful behavior when Gemeinschaft...... conditions rule. These propositions get support from five studies of members’ readership of their cooperatives’ annual reports. In large and heterogeneous memberships there is free-riding behavior, which explains the members’ low interest in governing their cooperatives. To a limited extent a membership may...

Effects of 4 Weeks of Horseback Riding on Anxiety, Depression, and Self-Esteem in Children with Attention Deficit Hyperactivity Disorder

Directory of Open Access Journals (Sweden)

Wi-Young So

2017-09-01

Full Text Available Background and Objective: There is no report on the effects of horseback riding on children with attention deficit hyperactivity disorder (ADHD. Therefore, the purpose of this study was to determine the effects of 4 weeks of horseback riding on anxiety, depression, self-esteem, attention, and learning disorder in children with ADHD. Material and Methods: Subjects comprised a convenience sample of 10 children aged 10-12 years with ADHD and 10 children without ADHD. Horseback riding sessions were performed 2 times (40 minutes/day per week for 4 weeks. Before and after the horseback riding program, we measured the children’s anxiety, depression, self-esteem, attention, and learning disorder. The pre-test and post-test scores were analyzed with repeated-measures analysis of variance. Results: After participating in the 4-week horseback riding program, anxiety (p = 0.013, depression (p = 0.007, attention (p < 0.001, and learning disorder (p < 0.001 were significantly improved in the ADHD group compared to the control group. However, self-esteem was not significantly different between the two groups (p=0.096. Conclusion: These results indicate that the 4-week horseback riding program used in this study was very effective for significantly improving anxiety, depression, and attention in children with ADHD.

Saturday Subway Ride: A Report on the Initial Tryout.

Science.gov (United States)

Quilling, Mary R.; And Others

"Saturday Subway Ride," a program designed to teach pupils creative thinking techniques and positive attitudes toward creative ideas, is a 92-page workbook in a story-exercise format. Secondary objectives for the product include improving verbal fluency and creative writing. Three classrooms 61 sixth graders and 34 fifth graders at two…

Control rod upper pin and roller removal and replacement

International Nuclear Information System (INIS)

Giordano, B.

1995-01-01

There has been increasing utility interest in removing cobalt sources as a means to minimize dose rates and shipping costs associated with operations, maintenance, shipping and radioactive waste disposal. This activation product accounts for approximately 80% of the dose rates at a plant. Estimates suggest that older (original equipment) control rod blades (CRBs) using stellite rollers and Haynes Alloy 25 pins can contribute as much as 43% of the cobalt in the plant. Since CRBs are the most concentrated source of cobalt in the reactor vessel, pin and roller (P ampersand R) replacement will provide significant reductions in cobalt-60 levels. The reductions will be measurable within 2 years, and should plateau within 5 to 6 years. This paper described a new, simple, cost effective, field proven in-situ method to replace these high source term contributing components and return the CRB to the reactor core for continued service. The paper also briefly describes a methodology that has been developed to estimate the labor and material costs along with a man-rem dollar savings for removal of the upper P ampersand Rs from in-service CRBs purchased prior to 1982. This method permits comparison to the cost of early replacement of CRBs. The result of this study is an EXCEL spreadsheet cost/benefit analysis that can be made plant specific by incorporation of plant data. The Analysis shows that the removal of P ampersand Rs can be beneficial for a Co-60 contribution as low as 5-10%. Recent interest by non-utility radioactive material users in obtaining the removed P ampersand Rs may further increase the benefit and reduce the cost associated with in-situ removal

A Sparsity-Promoted Decomposition for Compressed Fault Diagnosis of Roller Bearings

Directory of Open Access Journals (Sweden)

Huaqing Wang

2016-09-01

Full Text Available The traditional approaches for condition monitoring of roller bearings are almost always achieved under Shannon sampling theorem conditions, leading to a big-data problem. The compressed sensing (CS theory provides a new solution to the big-data problem. However, the vibration signals are insufficiently sparse and it is difficult to achieve sparsity using the conventional techniques, which impedes the application of CS theory. Therefore, it is of great significance to promote the sparsity when applying the CS theory to fault diagnosis of roller bearings. To increase the sparsity of vibration signals, a sparsity-promoted method called the tunable Q-factor wavelet transform based on decomposing the analyzed signals into transient impact components and high oscillation components is utilized in this work. The former become sparser than the raw signals with noise eliminated, whereas the latter include noise. Thus, the decomposed transient impact components replace the original signals for analysis. The CS theory is applied to extract the fault features without complete reconstruction, which means that the reconstruction can be completed when the components with interested frequencies are detected and the fault diagnosis can be achieved during the reconstruction procedure. The application cases prove that the CS theory assisted by the tunable Q-factor wavelet transform can successfully extract the fault features from the compressed samples.

Assessment of a rail vehicle running with the damaged wheel on a ride comfort for passengers

Directory of Open Access Journals (Sweden)

Dižo Ján

2018-01-01

Full Text Available In certain conditions rail vehicles wheels can be during operation damaged. Then, the profile of wheels is no longer circular, but it is changed depending on the type and severity of defects. When such rail vehicle with the damaged wheel operates, the quality of a ride comfort for passenger is degraded. This article is focused on the assessment of ride comfort for passenger based on results obtained from dynamic analyses. Simulations and calculations were carried out in commercial multibody software. In our research we considered one type of the railway wheel untrueness – wheel-flat. This type of wheel damaging is relatively common and has such influence on the ride comfort for passenger worsening, which needs to be detected and investigated.

Economic analysis of the organisation of a riding centre; application of the linear programming approach

Directory of Open Access Journals (Sweden)

Jaka ŽGAJNAR

2015-12-01

Full Text Available In this contribution, the economics of an equestrian centre, which in addition to a variety of riding school activities also includes breeding and livery, are analysed. We consider the conditions for a hypothetical holding operating in central Slovenia. Methods of mathematical programming are applied in order to attempt to optimise the holding’s activities. Their use may in the given situation facilitate the evaluation of development prospects from different perspectives and indicate the opportunities of increasing value-added. On the basis of maximizing the gross margin, we try to address the various questions and challenges that arise in managing and planning for such an equestrian centre. The obtained results indicate that breeding is unfavourable in the given price-cost ratio, both for the renewal of the working horses herd and for sale. This reflects the current adverse situation in the field of horse breeding. Livery is an important activity on such holdings and through opportunity perspective provides an optimal set of activities. Activities of the riding school for children are interesting in terms of income diversification, as well as an additional source of revenue. A riding school with one riding instructor and an indoor arena needs 4.6 horses in order to cover the costs of full-time employment.

Modeling of contact theories for the manipulation of biological micro/nanoparticles in the form of circular crowned rollers based on the atomic force microscope

International Nuclear Information System (INIS)

Korayem, M. H.; Khaksar, H.; Taheri, M.

2013-01-01

This article has dealt with the development and modeling of various contact theories for biological nanoparticles shaped as cylinders and circular crowned rollers for application in the manipulation of different biological micro/nanoparticles based on Atomic Force Microscope. First, the effective contact forces were simulated, and their impact on contact mechanics simulation was investigated. In the next step, the Hertz contact model was simulated and compared for gold and DNA nanoparticles with the three types of spherical, cylindrical, and circular crowned roller type contact geometries. Then by reducing the length of the cylindrical section in the circular crowned roller geometry, the geometry of the body was made to approach that of a sphere, and the results were compared for DNA nanoparticles. To anticipatory validate the developed theories, the results of the cylindrical and the circular crowned roller contacts were compared with the results of the existing spherical contact simulations. Following the development of these contact models for the manipulation of various biological micro/nanoparticles, the cylindrical and the circular crowned roller type contact theories were modeled based on the theories of Lundberg, Dowson, Nikpur, Heoprich, and Hertz for the manipulation of biological micro/nanoparticles. Then, for a more accurate validation, the results obtained from the simulations were compared with those obtained by the finite element method and with the experimental results available in previous articles. The previous research works on the simulation of nanomanipulation have mainly investigated the contact theories used in the manipulation of spherical micro/nanoparticles. However since in real biomanipulation situations, biological micro/nanoparticles of more complex shapes need to be displaced in biological environments, this article therefore has modeled and compared, for the first time, different contact theories for use in the biomanipulation of

Acute, fatal Sarcocystis calchasi-associated hepatitis in Roller pigeons (Columbia livia f. dom.) at Philadelphia Zoo

Science.gov (United States)

Four Roller pigeons (Columba livia f. dom.) at the Philadelphia Zoo died suddenly. Necropsy examination revealed macroscopic hepatitis. Microscopically, the predominant lesions were in liver, characterized with necrosis and mixed cell inflammatory response. Sarcocystis calchasi-like schizonts and fr...

Roller Bearing Monitoring by New Subspace-Based Damage Indicator

Directory of Open Access Journals (Sweden)

G. Gautier

2015-01-01

Full Text Available A frequency-band subspace-based damage identification method for fault diagnosis in roller bearings is presented. Subspace-based damage indicators are obtained by filtering the vibration data in the frequency range where damage is likely to occur, that is, around the bearing characteristic frequencies. The proposed method is validated by considering simulated data of a damaged bearing. Also, an experimental case is considered which focuses on collecting the vibration data issued from a run-to-failure test. It is shown that the proposed method can detect bearing defects and, as such, it appears to be an efficient tool for diagnosis purpose.

In-depth investigation of escalator riding accidents in heavy capacity MRT stations.

Science.gov (United States)

Chi, Chia-Fen; Chang, Tin-Chang; Tsou, Chi-Lin

2006-07-01

In 2000, the accident rate for escalator riding was about 0.815 accidents per million passenger trips through Taipei Metro Rapid Transit (MRT) heavy capacity stations. In order to reduce the probability and severity of escalator riding accidents and enhance the safety of passengers, the Drury and Brill model [Drury, C.G., Brill, M., 1983. Human factors in consumer product accident investigation. Hum. Factors 25 (3), 329-342] for in-depth investigation was adopted to analyze the 194 escalator riding accidents in terms of victim, task, product and environment. Prevention measures have been developed based on the major causes of accidents and other related contributing factors. The results from the analysis indicated that the majority of the escalator riding accidents was caused by passengers' carrying out other tasks (38 cases, including carrying luggage 24 cases, looking after accompany persons 9 cases, and 5 others), loss of balance (26 cases, 13.4%), not holding the handrail (20 cases, 10.3%), unhealthy passengers (18 cases, 9.3%), followed by people struck by other passenger (16 cases, 8.2%). For female passengers aged 15-64 years, their rushing for trains accidents could have been prevented by wearing safer footwear or by appropriate signing being provided indicating the location and traveling direction of escalators. Female passengers aged 65 years and above whose accidents were caused by loss of balance, should be encouraged to take the elevator instead. To prevent entrapment injuries, following a stricter design code can be most effective. Further in-depth accident investigation is suggested to cover the activity of the victim prior to the accident, any involved product, the location of the accident on the escalator, any medical treatment, what went wrong, opinion of the respondent on the causes of the accident, and personal characteristics of the passengers. Also, management must trade off productivity and safety appropriately to prevent "Organizational

Cognitive motivations of free riding and cooperation and impaired strategic decision making in schizophrenia during a public goods game.

Science.gov (United States)

Chung, Dongil; Kim, Yang-Tae; Jeong, Jaeseung

2013-01-01

Schizophrenia is generally characterized by various positive and negative symptoms that are accompanied by significant social dysfunction. Various researchers investigated the functional impairments in schizophrenia including impaired theory of mind (TOM), poor integration of affective and cognitive information, and malfunctioning of adaptive and strategic learning process. However, most of the studies were limited to simplified cognitive tests or computerized choice games that exclude real social interaction. The aim of the current study was to investigate human strategies based on the incentives and particularly the cognitive and emotional motivations of free riding. We examined the decision patterns of 41 healthy subjects (HSs) and 37 schizophrenia patients (SZ) during the public goods game (PGG), one of the games simulating human cooperation and free riding in group interactions. Strategic decision processes during the iterative binary PGG were assessed in terms of cognitive understanding, loss sensitivity, and TOM. We found that greed and loss sensitivity both motivated free-riding behavior in the HS, but that they were more vulnerable to greedy incentives than to possible loss. More significantly, the SZ clearly displayed a lower prevalence of free riding and distinct decision patterns from HS. Nonstrategic and unexpectedly low free ridings in the SZ likely arise from poor integration of cognitive and affective information. We suggest that loss sensitivity and TOM as well as cognitive understanding are involved in regulation of the free riding and cooperative behavior.

Improving Vehicle Ride and Handling Using LQG CNF Fusion Control Strategy for an Active Antiroll Bar System

Directory of Open Access Journals (Sweden)

N. Zulkarnain

2014-01-01

Full Text Available This paper analyses a comparison of performance for an active antiroll bar (ARB system using two types of control strategy. First of all, the LQG control strategy is investigated and then a novel LQG CNF fusion control method is developed to improve the performances on vehicle ride and handling for an active antiroll bar system. However, the ARB system has to balance the trade-off between ride and handling performance, where the CNF consists of a linear feedback law and a nonlinear feedback law. Typically, the linear feedback is designed to yield a quick response at the initial stage, while the nonlinear feedback law is used to smooth out overshoots in the system output when it approaches the target reference. The half car model is combined with a linear single track model with roll dynamics which are used for the analysis and simulation of ride and handling. The performances of the control strategies are compared and the simulation results show the LQG CNF fusion improves the performances in vehicle ride and handling.

The effect of extrusion and drying on roller techniques concerning the rheological characteristics of rice-, corn-, sweet potato-, bean- and cassava root- and leaf- based composite flour

Directory of Open Access Journals (Sweden)

Johanna Aristizábal Galvis

2013-01-01

Full Text Available Promoting food security in Latin-America and the Caribbean is directly related to agricultural products. The region faces a food crisis which has reduced large population groups’ access to food. This work contributes to the study of obtaining precooked composite flour made from biofortified crops using protein, vitamin A and/or minerals. This study evaluated the effect of precooked flour’s composition and precooking on its solubility in water, water absorption capacity, consistency and viscosity; such flour was obtained by extrusion and drying on rollers. The composite flours were obtained from cassava roots, sweet potato tubers, corn, rice and bean grains and cassava leaves. Four composite flours were formulated taking four- to six-year-old children’s daily nutrient requirements (protein, iron, zinc and beta-carotenes as a basis. The extruder was operated at 90ºC, 300 rpm screw rotation speed, 17.64 g/min feed flow, with 30% moisture mixture. The dryer rollers were operated at 4 rpm roller rotation speed, 90ºC surface temperature and 1 mm separation between rollers. It was determined that flour dried on rollers led to more complete cooking and modified starch granule structure than precooking by extrusion, thereby producing flour having greater solubility in water, less water absorption, higher consistency and smaller viscosity, comparable to that of pattern flour.

Cooperate or Free Ride?

DEFF Research Database (Denmark)

Hansen, Per H.

2012-01-01

of international cooperation. On the other hand, the evidence seems to confirm Kindleberger's hypothesis that small countries were free riding during the international financial crisis of 1931, and that therefore there is a need for some coordinating mechanism, or a hegemon, in such crises....... in the establishment of the BIS and free riders in the Austrian crisis, even though there were marked differences in their attitude to international cooperation. These results run counter to the views of those International Political Economy (IPE) theorists who argue that small states should be in favour......In this article, I discuss the role of the three Scandinavian central banks in the establishment of the Bank for International Settlements (BIS) in 1930, and in the international lender of last resort operation towards Austria in 1931. I argue that small central banks were reluctant supporters...

The choice of Park & Ride Facilities: an analysis using a context-dependent hierarchical choice experiment

OpenAIRE

Heijden, R.E.C.M. van der; Molin, E.J.E.; Timmermans, H.J.P.

2004-01-01

Park and Ride facilities have been proposed in several countries to alleviate the accessibility problems in cities. Despite growing accessibility problems, these facilities do not seem to attract the expected number of car drivers and are under-used. In an attempt to measure consumer evaluations of the attributes of Park and Ride facilities, a stated choice experiment, based on the method of hierarchical information integration, was conducted in the city of Nijmegen, The Netherlands. This pap...

An approach to high speed ship ride quality simulation

Science.gov (United States)

Malone, W. L.; Vickery, J. M.

1975-01-01

The high speeds attained by certain advanced surface ships result in a spectrum of motion which is higher in frequency than that of conventional ships. This fact along with the inclusion of advanced ride control features in the design of these ships resulted in an increased awareness of the need for ride criteria. Such criteria can be developed using data from actual ship operations in varied sea states or from clinical laboratory experiments. A third approach is to simulate ship conditions using measured or calculated ship motion data. Recent simulations have used data derived from a math model of Surface Effect Ship (SES) motion. The model in turn is based on equations of motion which have been refined with data from scale models and SES of up to 101 600-kg (100-ton) displacement. Employment of broad band motion emphasizes the use of the simulators as a design tool to evaluate a given ship configuration in several operational situations and also serves to provide data as to the overall effect of a given motion on crew performance and physiological status.

Hospital-treated injuries from horse riding in Victoria, Australia: time to refocus on injury prevention?

Science.gov (United States)

O'Connor, Siobhán; Hitchens, Peta L; Fortington, Lauren V

2018-01-01

The most recent report on hospital-treated horse-riding injuries in Victoria was published 20 years ago. Since then, injury countermeasures and new technology have aimed to make horse riding safer for participants. This study provides an update of horse-riding injuries that required hospital treatment in Victoria and examines changes in injury patterns compared with the earlier study. Horse-riding injuries that required hospital treatment (hospital admission (HA) or emergency department (ED) presentations) were extracted from routinely collected data from public and private hospitals in Victoria from 2002-2003 to 2015-2016. Injury incidence rates per 100 000 Victorian population per financial year and age-stratified and sex-stratified injury incidence rates are presented. Poisson regression was used to examine trends in injury rates over the study period. ED presentation and HA rates were 31.1 and 6.6 per 100 000 person-years, increasing by 28.8% and 47.6% from 2002 to 2016, respectively. Female riders (47.3 ED and 10.1 HA per 100 000 person-years) and those aged between 10 and 14 years (87.8 ED and 15.7 HA per 100 000 person-years) had the highest incidence rates. Fractures (ED 29.4%; HA 56.5%) and head injuries (ED 15.4%; HA 18.9%) were the most common injuries. HA had a mean stay of 2.6±4.1 days, and the mean cost per HA was $A5096±8345. Horse-riding injuries have remained similar in their pattern (eg, types of injuries) since last reported in Victoria. HA and ED incidence rates have increased over the last 14 years. Refocusing on injury prevention countermeasures is recommended along with a clear plan for implementation and evaluation of their effectiveness in reducing injury.

Benefits of Hippotherapy and Horse Riding Simulation Exercise on Healthy Older Adults: A Systematic Review.

Science.gov (United States)

Hilliere, Camille; Collado-Mateo, Daniel; Villafaina, Santos; Duque-Fonseca, Paulo; Parraça, José A

2018-04-05

To provide an up-to-date research analysis on equine-assisted therapies and horse riding simulation exercise in older adults, and to suggest future directions in clinical practice and research. TYPE: Systematic review. A comprehensive search of studies was performed in 4 electronic databases (Cochrane, PubMed, PEDro, and Web of Science) regarding the effects of equine-assisted therapies and horse riding simulation exercise in older adults. Eight articles were selected, 5 of them focused on hippotherapy, 2 on horse riding simulation, and a single article that used the 2 types of therapy. PRISMA guidelines were followed for the data extraction process. The studies were all randomized controlled trials, but not double-blind, so they were classified as level of evidence B. Duration of hippotherapy programs ranged from 8-12 weeks. Sessions lasted between 15 and 60 minutes and were performed 2-5 times per week. Interventions using a horse simulator spanned 8 weeks and were conducted for 20 minutes 5 times per week. Results indicate that hippotherapy might improve balance, mobility, gait ability, and muscle strength, as well as could induce hormonal and cerebral activity changes in healthy older adults. Benefits of horse riding simulation could be limited to physical fitness and muscular activity. ▪▪▪. Copyright © 2018 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Effect of Health Education on the Riding Habits of Commercial ...

African Journals Online (AJOL)

METHODS: The intervention study was conducted among commercial motorcyclists in Uyo with controls from another town in Akwa Ibom State. Baseline information was collected from both groups on their riding habits. Motorcyclists in Uyo were educated on appropriate road safety practices. Data was collected from both ...

Fancy a ride?

CERN Multimedia

Anaïs Schaeffer

2014-01-01

This Sunday 7 September, don’t miss your chance to climb into a supercar, one of those exceptional machines that tear up the tracks and that you sometimes hear revving their engines on the motorway. The 2014 supercar experience day, organised by members of CERN, will allow car lovers to go for a ride in style and all for a good cause!   Supercars at the 2013 experience day. Photo: Kevin Mazzilli. If you have always dreamt of sitting in a Ferrari, feeling the vibrations of a Lamborghini, or losing yourself in the hushed calm of a classic car, don’t miss the supercar experience day taking place on Sunday, 7 September! This event has been organised by CERN’s own car enthusiasts, in collaboration with the charity Kumansansa – Children of Zambia, founded by two CERN members. It will take place for the third consecutive year in the car park of the Macumba leisure centre in Saint-Julien-en-Genevois (France). From 9.30 a.m. to 6 p.m., visitors old and young (c...

Exploring Spatiotemporal Patterns of Long-Distance Taxi Rides in Shanghai

Directory of Open Access Journals (Sweden)

Hangbin Wu

2017-11-01

Full Text Available Floating Car Data (FCD has been analyzed for various purposes in past years. However, limited research about the behaviors of taking long-distance taxi rides has been made available. In this paper, we used data from over 12,000 taxis during a six-month period in Shanghai to analyze the spatiotemporal patterns of long-distance taxi trips. We investigated these spatiotemporal patterns by comparing them with metro usage in Shanghai, in order to determine the extent and how the suburban trains divert the passenger flow from taxis. The results identified 12 pick-up and six drop-off hotspots in Shanghai. Overall, the pick-up locations were relatively more concentrated than the drop-off locations. Temporal patterns were also revealed. Passengers on long-distance taxi rides were observed to avoid the rush hours on the street as their first priority and tried to avoid the inconvenience of interchanges on the metro lines as their second priority.

Measurements of Wake-Riding Electrons in Antiproton-Carbon-Foil Collisions

CERN Multimedia

2002-01-01

When a charged particle passes through dielectric media, e.g. a thin carbon foil, a ``wake'' is induced. The characteristic wake-potential shows an oscillatory behaviour, with a wavelength of about $ 2 \\pi v _{p} / \\omega _{p} _{l} $ where $ v _{p} $ is the projectile velocity and $ \\omega _{p} _{l} $ the plasmon energy of the target. This induced wake potential is superimposed on the Coulomb potential of the projectile, the latter leading to a pronounced ``cusp'' of electrons leaving the solid at $ v _{e} app v _{p} $ for positively charged projectiles in the MeV region. Correspondingly, an ``anti-cusp'' is expected for antiprotons. \\\\ \\\\ In the solid, the wake-potential leads to an attractive force on electrons, and a dynamic electronic state is predicted both for proton and antiproton projectiles. In the solid, the wake-riding electrons are travelling with the projectile speed $ v _{p} $ Upon exit of the foil, the electron released from the wake-riding state of an antiproton will suddenly find itself in th...

78 FR 58996 - Tapered Roller Bearings from the People's Republic of China: Notice of Court Decision Not in...

Science.gov (United States)

2013-09-25

... Sawblades Mfrs. Coalition v. United States, 626 F.3d 1374 (Fed. Cir. 2010) (``Diamond Sawblades''), the... a complaint with the CIT to challenge various aspects of the Final Results. \\2\\ Tapered Roller...

Second-order sliding mode control for DFIG-based wind turbines fault ride-through capability enhancement.

Science.gov (United States)

Benbouzid, Mohamed; Beltran, Brice; Amirat, Yassine; Yao, Gang; Han, Jingang; Mangel, Hervé

2014-05-01

This paper deals with the fault ride-through capability assessment of a doubly fed induction generator-based wind turbine using a high-order sliding mode control. Indeed, it has been recently suggested that sliding mode control is a solution of choice to the fault ride-through problem. In this context, this paper proposes a second-order sliding mode as an improved solution that handle the classical sliding mode chattering problem. Indeed, the main and attractive features of high-order sliding modes are robustness against external disturbances, the grids faults in particular, and chattering-free behavior (no extra mechanical stress on the wind turbine drive train). Simulations using the NREL FAST code on a 1.5-MW wind turbine are carried out to evaluate ride-through performance of the proposed high-order sliding mode control strategy in case of grid frequency variations and unbalanced voltage sags. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Role of Bioethanol in Global Climate Change

Energy Technology Data Exchange (ETDEWEB)

Sheehan, John [National Renewable Energy Lab. (NREL), Golden, CO (United States)

1998-01-01

The United States Department of Energy (DOE) has supported a research and development program for the establishment of renewable, biomass-derived, liquid fuels for the better part of the last twenty years. These 'biofuels' represent opportunities to respond to uncertainties about our energy security and the future health of our environment. Throughout its history, the Biofuels program has experienced an ongoing fiscal 'roller coaster'. Funding has ebbed and flowed with changing political and public attitudes about energy. The program was initiated in a flood of funding in the late 1970s related to the energy shortages experienced in that period. The flooding turned rapidly to drought as falling oil prices dissipated public concern about energy supplies. In the late 1980s, funding for the program slowly increased, driven by national security issues.

Electromagnetic validation of fault-ride through capabilities of wind turbines

DEFF Research Database (Denmark)

Arana Aristi, Iván; Garcia-Valle, Rodrigo; Sharma, Ranjan

2010-01-01

Scope of the present project is the development and validation of electro-magnetic transient model of fixed-speed wind turbines. The research work is focused on the development of a fixed-speed wind turbine model with fault-ride through capabilities during transient over-voltages. The model is de...

78 FR 45912 - Tapered Roller Bearings and Parts Thereof, Finished and Unfinished, From the People's Republic of...

Science.gov (United States)

2013-07-30

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-601] Tapered Roller Bearings and..., International Trade Administration, U.S. Department of Commerce, 14th Street and Constitution Avenue NW... Duty New Shipper Review AGENCY: Import Administration, International Trade Administration, Department...

Supercapacitor energy storage system for fault ride-through of a DFIG wind generation system

International Nuclear Information System (INIS)

Rahim, A.H.M.A.; Nowicki, E.P.

2012-01-01

Highlights: ► A detailed dynamic model of a DFIG is developed to study the low voltage ride-through phenomenon. ► A supercapacitor-STATCOM energy storage system is employed. ► Decoupled real and reactive power control strategies implemented on the system. ► The proposed controller show extremely good transient behavior following low voltage conditions. - Abstract: The doubly fed induction generators (DFIGs) are preferred over other variable speed generators because of their advantages in terms of economy and control. One of the problems associated with high wind power penetration DFIG systems, however, is the inability of their converters to work properly under extreme low voltage conditions. This article presents a decoupled P–Q control strategy of a supercapacitor energy storage system, interfaced through a STATCOM, for low voltage ride through as well as damping enhancement of the DFIG system. The STATCOM meets the reactive power need under the depressed voltage condition, while the supercapacitor caters to the real power unbalance. An extensive dynamic model of the DFIG system including a supercapacitor DC–DC buck–boost converter and the STATCOM circuit has been developed. The fault ride-thorough capability of the generator has been investigated for a severe symmetrical three-phase to ground fault on the grid bus. Simulation results suggest that the proposed decoupled control of the supercapacitor STATCOM control strategy can help the DFIG ride through extreme low voltage conditions for significant duration. The proposed control strategy also damps the electromechanical transients, and thus quickly restores normal operation of the converters.

The positioning of federate sports in Portugal: handball, basketball, roller hockey and volleyball

OpenAIRE

Gonçalves, Celina; Correia, Abel

2005-01-01

Sport is constituted by a multiplicity of activities with different purposes, concepts and cultural representations. Before the increase of supply, Sports Federations need to understand the practitioners in relation to the several possibilities of practice and to position their sports according to their competitors. In this context, the purpose of this study is the positioning of team federate sports (handball, basketball, roller hockey and volleyball). According to Lindon et al.,...

High performance AC–DC control power supply for low voltage ride ...

Indian Academy of Sciences (India)

Ride-Through (LVRT) in solar and wind applications, no work has been ... section 5. Figure 2. Schematic structure of a control power supply used in a HPC. ..... order plant transfer function to first order transfer function. Also, peak current ...

78 FR 40692 - Tapered Roller Bearings and Parts Thereof, Finished and Unfinished, From the People's Republic of...

Science.gov (United States)

2013-07-08

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-601] Tapered Roller Bearings and..., International Trade Administration, Department of Commerce. SUMMARY: The Department of Commerce (Department) is... Department selected one mandatory respondent for individual examination (i.e., Changshan Peer Bearing Co. Ltd...

Fault Ride-Through of a Grid-connected Photovoltaic System with Quasi Z Source Inverter

DEFF Research Database (Denmark)

Al-Durra, Ahmed; Fayyad, Yara; Muyeen, S.M.

2016-01-01

This article presents fault ride-through schemes for a three-phase quasi Z source single-stage photovoltaic (PV) inverter that is connected to the grid after the distribution network. The quasi Z source inverter employs a unique LC network to couple the inverter main circuit to the input of the PV...... the grid side so that the grid fault ride-through requirements can be fulfilled. Scheme A involves control modification in the system; Schemes B and C involve hardware modification in the circuit topology by adding a chopper circuit across the DC link in Scheme B and across the quasi Z source inverter...

Undoing Quantitative Easing: Janet Yellen's Tiger Ride

Science.gov (United States)

Niederjohn, M. Scott; Schug, Mark C.; Wood, William C.

2014-01-01

"One who rides a tiger is afraid to dismount," says a colorful proverb from an earlier time. This may be an apt saying for the situation facing the new head of the Federal Reserve, Janet L. Yellen, who takes over at a time when successive rounds of Fed policy have taken the central bank into uncharted territory. By historical standards,…

Zero-Voltage Ride-Through Capability of Single-Phase Grid-Connected Photovoltaic Systems

Directory of Open Access Journals (Sweden)

Zhen Zhang

2017-03-01

Full Text Available Distributed renewable energy systems play an increasing role in today’s energy paradigm. Thus, intensive research activities have been centered on improving the performance of renewable energy systems, including photovoltaic (PV systems, which should be of multiple-functionality. That is, the PV systems should be more intelligent in the consideration of grid stability, reliability, and fault protection. Therefore, in this paper, the performance of single-phase grid-connected PV systems under an extreme grid fault (i.e., when the grid voltage dips to zero is explored. It has been revealed that combining a fast and accurate synchronization mechanism with appropriate control strategies for the zero-voltage ride-through (ZVRT operation is mandatory. Accordingly, the representative synchronization techniques (i.e., the phase-locked loop (PLL methods in the ZVRT operation are compared in terms of detection precision and dynamic response. It shows that the second-order generalized integrator (SOGI-PLL is a promising solution for single-phase systems in the case of fault ride-through. A control strategy by modifying the SOGI-PLL scheme is then introduced to single-phase grid-connected PV systems for ZVRT operation. Simulations are performed to verify the discussions. The results have demonstrated that the proposed method can help single-phase PV systems to temporarily ride through zero-voltage faults with good dynamics.

Park-and-Ride motivations and air quality norms in Europe

NARCIS (Netherlands)

Dijk, Marc; de Haes, Jan; Montalvo, Carlos

2013-01-01

Transport congestion and the quality of the air in cities is a persistent concern for urban planners, and in this context Park and Ride (P. +. R) facilities have been proposed as an element of urban sustainability strategies in many cities in Europe. In 2008 a European Commission directive aimed at

The Selection of Materials for Roller Chains From The Perspective Of Manufacturing Process

Directory of Open Access Journals (Sweden)

Rahmat Saptono

2010-10-01

Full Text Available The selection of materials for an engineering component is not only requested by its design function and shape, but also the sequence through which it is manufactured. The manufacturing operation of roller chains involves drawing and trimming processes aimed at producing semi-finished chain drives component with a well-standardized dimension. In addition to final combination of properties required by design constraints, the ability of materials to be formed into a desired shape and geometry without failure is also critical. The objective of materials selection should therefore involve additional attributes that are not typically  accommodated by the standard procedure of materials selection. The present paper deals with the selection of materials for roller chains from the perspective of manufacturing process. Ears and un-uniform wall thickness have been identified as a key problem in the mass production of component. Provided all process parameters were established, the  anisotropy factor of materials is critical. Simulative test can be reasonably used to obtain material performance indices that can be added up to the standard procedure of material selection. Of three commercially available steel grades evaluated with regard to the criteria defined, one grade is more suitable for the present objective.

Therapeutic riding followed by rhythmic auditory stimulation to improve balance and gait in a subject with orthopedic pathologies.

Science.gov (United States)

Ungermann, Cathryn M; Gras, Laura Z

2011-12-01

The study objectives were to investigate the effect of therapeutic riding with a subject who had an orthopedic diagnosis. This is a single-subject case report. The study was conducted at an equestrian facility with an indoor riding arena. The subject was a 59-year-old woman with grade I spondylolisthesis at L4/L5 and multilevel lumbar spinal stenosis in central and foraminal canals. The subject had an anterior cervical fusion of C3-C7. The subject has been ambulating with a straight cane due to her history of frequent falls. Gait, agility, strength, range of motion, and balance testing were performed. The subject had impairments of bilateral lower extremities with an ataxic gait pattern and was at risk for continued falls according to the balance measures. The intervention comprised therapeutic riding sessions 3 times a week for 20 minutes for 4 weeks. Each riding session was immediately followed by a 10-minute independent walking program with a metronome for rhythmic auditory stimulation. The outcome measures were as follows: Manual muscle testing and range of motion of the lower extremities, Gait Speed Test, Dynamic Gait Index, Four-Square Step Test, Chair Stand Test, Single Leg Stance. Improvements were seen in lower extremity strength and range of motion and balance. The subject improved on balance scores, placing her out of the risk for falls category. Therapeutic riding followed by rhythmic auditory stimulation improved lower extremity range of motion, strength, and balance with this subject.

Watching Your Back While Riding Your Bike

DEFF Research Database (Denmark)

Sokoler, Tomas; Bagalkot, Naveen

2017-01-01

series of investigations looking into the broader notion of integrating measures for preventive self-care with existing everyday activities (e.g daily motorcycle commute) by means of digital technology. We are guided by the concept of embodied self-monitoring grounded in theories on the embodied...... for interaction design in the domain of preventive self-care. We report on the outcome of in-situ enactments performed by four motorbike riders as co-explorers engaging with our interactive soft&hardware sketches while actually riding in traffic. Insitu enactments and follow-up interviews with the riders...

Kuhu kadus pensionäride kogutud 25 000 allkirja? / Jaanus Kõrv

Index Scriptorium Estoniae

Kõrv, Jaanus

2005-01-01

2003. aasta novembri alguses andsid Eesti Pensionäride Ühenduse esindajad ajalehe Videvik kaasabil üle Riigikogu spiikrile Ene Ergmale pöördumise 25 000 protestiallkirjaga, milles nõuti inimväärset pensioni. Valitsus pole pöördumisele reageerinud

Compressive Sensing of Roller Bearing Faults via Harmonic Detection from Under-Sampled Vibration Signals.

Science.gov (United States)

Tang, Gang; Hou, Wei; Wang, Huaqing; Luo, Ganggang; Ma, Jianwei

2015-10-09

The Shannon sampling principle requires substantial amounts of data to ensure the accuracy of on-line monitoring of roller bearing fault signals. Challenges are often encountered as a result of the cumbersome data monitoring, thus a novel method focused on compressed vibration signals for detecting roller bearing faults is developed in this study. Considering that harmonics often represent the fault characteristic frequencies in vibration signals, a compressive sensing frame of characteristic harmonics is proposed to detect bearing faults. A compressed vibration signal is first acquired from a sensing matrix with information preserved through a well-designed sampling strategy. A reconstruction process of the under-sampled vibration signal is then pursued as attempts are conducted to detect the characteristic harmonics from sparse measurements through a compressive matching pursuit strategy. In the proposed method bearing fault features depend on the existence of characteristic harmonics, as typically detected directly from compressed data far before reconstruction completion. The process of sampling and detection may then be performed simultaneously without complete recovery of the under-sampled signals. The effectiveness of the proposed method is validated by simulations and experiments.

Taurine protects DNA of lymphocytes against oxidative alteration in riding horses

DEFF Research Database (Denmark)

Sokól, Janusz Leszek; Sawosz, Ewa; Niemiec, Tomasz

2009-01-01

The study aimed at evaluation the effect of dietary supplement of taurine on the oxidation-reduction status in riding horses, and especially on the extent of oxidative DNA degradation in lymphocytes. Ten Thoroughbred and half-bred geldings aged 6-13 years were classified according to breed...... and amount of work done into two groups - control (C, n=5) and experimental (E, n=5), the latter fed the diet with addition of 40 g taurine/horse/day. Blood samples were withdrawn from the horses' jugular vein before commencing the riding season and then after 30 days of working. In the blood some selected....... The addition of taurine to feed caused smaller oxidative stress, manifested by lower concentration of TBA-RS in plasma and of 8-oxo-dG in lymphocytes. The taurine lowered the lipid peroxidation intensity that occurred in horses due to the oxidative stress caused by physical effort. Furthermore, taurine...

Optimization of Vehicle Suspension Parameters for Ride Comfort Based on RSM

Science.gov (United States)

Mitra, A. C.; Patil, M. V.; Banerjee, N.

2015-04-01

Vehicle suspension design requires an investigation to determine the spring and damper settings that assure optimal ride comfort (RC) of vehicle. In the present work response surface methodology (RSM), one of the methods of design of experiment has been successfully implemented for the purpose of finding optimal setting. Design of experiment sometimes requires accurate representation of the independent variables which are usually difficult to measure or else unavailable for experimentation. This paper proposes a simulation model to analyze the ride comfort with accurate independent variables as per Box-Behnken design of RSM. A prediction model of response variable, RC is developed using regression analysis which leads to a good agreement with simulated model ( R 2 = 99.74 %). The fitted model can be effectively used to evaluate optimal setting of spring stiffness and damping coefficient with the help of response optimization of a high desirability value.

Fast Coordinated Control of DFIG Wind Turbine Generators for Low and High Voltage Ride-Through

DEFF Research Database (Denmark)

Wang, Yun; Wu, Qiuwei; Xu, Honghua

2014-01-01

This paper presents a fast coordinated control scheme of the rotor side converter (RSC), the DC chopper and the grid side converter (GSC) of doubly fed induction generator (DFIG) wind turbine generators (WTGs) which is to improve the low voltage ride through (LVRT) and high voltage ride through...... were proposed considering the characteristics of the DFIG WTGs during voltage changes. The fast coordinated control of RSC and GSC were developed based on the characteristic analysis in order to realize efficient LVRT and HVRT of the DFIG WTGs. The proposed fast coordinated control schemes were...

Union Free-Riding in Britain and New Zealand

OpenAIRE

Alex Bryson

2006-01-01

The percentage of workers who choose not to join the union available to them at their workplace has been rising in Britain and New Zealand. Social custom, union instrumentality, the fixed costs of joining, employee perceptions of management attitudes to unionization and employee problems at work all influence the propensity to free-ride. Ideological convictions regarding the role of unions also play some role, as do private excludable goods. There is little indication of employer-inspired pol...

Cyclist's nodule: no smooth ride.

Science.gov (United States)

Stoneham, Adam; Thway, Khin; Messiou, Christina; Smith, Myles

2016-03-10

A fit and active amateur cyclist was referred by his general practitioner to a surgical oncology outpatient clinic with a slowly-growing perineal mass. Following clinical examination, the patient underwent imaging and biopsy at a tertiary soft tissue tumour centre, which diagnosed perineal nodular induration: a rare, benign tumour caused by repetitive trauma associated with 'saddle sports' such as cycling or horse riding. It is important to consider soft tissue tumours in patients who present with 'lumps and bumps'; they can occur anywhere in the body including the groin or perineum, where it is sometimes referred to as a 'third' or 'accessory' testicle in men. Although unusual, the case emphasises the importance of rapid specialist referral from primary care, and consideration of a patient's occupation and hobbies when formulating diagnoses. 2016 BMJ Publishing Group Ltd.

Non conventional psychiatric rehabilitation in schizophrenia using therapeutic riding: the FISE multicentre Pindar project

Directory of Open Access Journals (Sweden)

Stefania Cerino

2011-12-01

Full Text Available The FISE (Federazione Italiana Sport Equestri Pindar is a multicentre research project aimed at testing the potential effects of therapeutic riding on schizophrenic patients. Twenty-four subjects with a diagnosis of schizophrenia were enrolled for a 1 year-treatment involving therapeutic riding sessions. All subjects were tested at the beginning and at the end of treatment with a series of validated test batteries (BPRS and 8 items-PANSS. The results discussed in this paper point out an improvement in negative symptoms, a constant disease remission in both early onset and chronic disease subjects, as well as a reduced rate of hospitalization.

Lab-scale roller table mill for investigating the grinding behaviour of coal

Energy Technology Data Exchange (ETDEWEB)

Werner, V.; Zelkowski, J.; Schoenert, K. [Inst. for Energy Process Engineering and Fuel Technology and Inst. of Mineral Processing, Univ. Clausthal, Clausthal-Zellerfeld (Germany)

1999-11-01

The test mill is equipped with one roller. The material bed can be discharged completely after overroling. Grinding force, torque and gap width are measured. Cycle tests with three coals have been performed for simulating a closed circuit process. The grinding behaviour is characterized by the following relations: compaction of the particle bed and specific power draft vs. specific grinding force, production of fine material (dust), circuit factor, specific surface of the dust and specific work-input of the grinding circuit vs. specific power draft. (orig.)

Effects of Indoor Horseback Riding and Virtual Reality Exercises on the Dynamic Balance Ability of Normal Healthy Adults

Science.gov (United States)

Lee, Daehee; Lee, Sangyong; Park, Jungseo

2014-01-01

[Purpose] The objective of this study was to determine the effect of indoor horseback riding and virtual reality exercises on the dynamic balance ability of normal adults. [Subjects] This study enrolled 24 normal adults and divided them into two groups: an indoor horseback riding exercise group (IHREG, n = 12) and a virtual reality exercise group (VREG, n = 12). [Methods] IHREG exercised on indoor horseback riding equipment and VREG exercised using the Nintendo Wii Fit three times a week for six weeks. The Biodex Balance System was used to analyze dynamic balance as measured by the overall stability index (OSI), anteroposterior stability index (APSI), and mediolateral stability index (MLSI). [Results] In the within-group comparison, IHREG and VERG both showed significant decreases in the dynamic balance indexes of OSI, APSI, and MLSI after the intervention, but no significant difference was found between the groups. [Conclusion] Both indoor horseback riding and virtual reality exercises were effective at improving the subjects’ dynamic balance ability as measured by OSI, APSI, and MLSI, and can be used as additional exercises for patients with conditions affecting postural control. PMID:25540494

Marine aggregates and transparent exopolymeric particles (TEPs) as substrates for the stramenopilan fungi, the thraustochytrids: Roller table experimental approach.

Digital Repository Service at National Institute of Oceanography (India)

Damare, V.S.; Raghukumar, S.

In order to understand the kind of organic substrates utilized by thraustochytrids in the coastal water column, their growth in the presence of Transparent Exopolymeric Substances (TEPS) and aggregates generated in roller table experiments...

Predictive routing for autonomous mobility-on-demand systems with ride-sharing

NARCIS (Netherlands)

Alonso Mora, J.; Wallar, Alex; Rus, Daniela; Bicchi, A.; Maciejewski, T.

2017-01-01

Ride-sharing, or carpooling, systems with autonomous vehicles will provide efficient and reliable urban mobility on demand. In this work we present a method for dynamic vehicle routing that leverages historical data to improve the performance of a network of self-driving taxis. In particular, we

Traveler Preference for Park-and-Ride Facilities: Empirical Evidence of Generalizability

NARCIS (Netherlands)

Bos, D.M.; Heijden, R.E.C.M. van der; Molin, E.; Timmermans, H.

2005-01-01

This paper reports the main findings of a study, conducted in the Netherlands, aimed at testing whether preference functions for park-and-ride facilities, estimated from data collected in a specific Dutch region, can be generalized to a nationwide sample. Preference data in both samples were

A comparison of optimal semi-active suspension systems regarding vehicle ride comfort

Science.gov (United States)

Koulocheris, Dimitrios; Papaioannou, Georgios; Chrysos, Emmanouil

2017-10-01

The aim of this work is to present a comparison of the main semi active suspension systems used in a passenger car, after having optimized the suspension systems of the vehicle model in respect with ride comfort and road holding. Thus, a half car model, equipped with controllable dampers, along with a seat and a driver was implemented. Semi-active suspensions have received a lot of attention since they seem to provide the best compromise between cost (energy consumption, actuators/sensors hardware) and performance in comparison with active and passive suspensions. In this work, the semi active suspension systems studied are comfort oriented and consist of (a) the two version of Skyhook control (two states skyhook and skyhook linear approximation damper), (b) the acceleration driven damper (ADD), (c) the power driven damper (PDD), (d) the combination of Skyhook and ADD (Mixed Skyhook-ADD) and (e) the combination of the two with the use of a sensor. The half car model equipped with the above suspension systems was excited by a road bump, and was optimized using genetic algorithms (GA) in respect with ride comfort and road holding. This study aims to highlight how the optimization of the vehicle model could lead to the best compromise between ride comfort and road holding, overcoming their well-known trade-off. The optimum results were compared with important performance metrics regarding the vehicle’s dynamic behaviour in general.

77 FR 2031 - Tapered Roller Bearings and Parts Thereof, Finished and Unfinished From the People's Republic of...

Science.gov (United States)

2012-01-13

... Parts Thereof, Finished and Unfinished From the People's Republic of China: Extension of the Time Limit..., International Trade Administration, U.S. Department of Commerce, 14th Street and Constitution Avenue NW..., finished and unfinished from the People's Republic of China. See Tapered Roller Bearings and Parts Thereof...

76 FR 76143 - Tapered Roller Bearings and Parts Thereof, Finished and Unfinished, From the People's Republic of...

Science.gov (United States)

2011-12-06

..., the United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service... manufacturing of tapered roller bearings and parts thereof in the United States, also notified the Department... manufacturing the domestic like product, and therefore, is an interested party pursuant to section 771(9)(D) of...

Fault Ride Through Enhancement of VSC‐HVDC Connected Offshore Wind Power Plants

DEFF Research Database (Denmark)

Sharma, Ranjan; Wu, Qiuwei; Jensen, Kim Høj

2018-01-01

the model of a VSC‐HVDC‐connected offshore wind power plant (WPP) with an external grid. It proposes a feedforward DC voltage control based FRT technique to control the AC voltage at the WPP collector network during grid‐side faults. Time‐domain simulations have been used to verify the efficacy......Voltage source converter‐high voltage direct current (VSC‐HVDC) connections have become a new trend for long‐distance offshore wind power transmission. In order to facilitate the derivation of the feedforward DC voltage control based fault ride through (FRT) technique, this chapter describes...... of the proposed feedforward DC voltage control based FRT technique for VSC‐HVDC‐connected WPPs. Time‐domain simulation results shows that the proposed FRT scheme can successfully enable VSC‐HVDC‐connected WPPs to ride through balanced and unbalanced faults in host power systems, as well as faults in the WPP...

Post-cracking tensile behaviour of steel-fibre-reinforced roller-compacted-concrete for FE modelling and design purposes

International Nuclear Information System (INIS)

Jafarifar, N.; Pilakoutas, K.; Angelakopoulos, H.; Bennett, T.

2017-01-01

Fracture of steel-fibre-reinforced-concrete occurs mostly in the form of a smeared crack band undergoing progressive microcracking. For FE modelling and design purposes, this crack band could be characterised by a stress-strain (σ-ε) relationship. For industrially-produced steel fibres, existing methodologies such as RILEM TC 162-TDF (2003) propose empirical equations to predict a trilinear σ-ε relationship directly from bending test results. This paper evaluates the accuracy of these methodologies and their applicability for roller-compacted-concrete and concrete incorporating steel fibres recycled from post-consumer tyres. It is shown that the energy absorption capacity is generally overestimated by these methodologies, sometimes up to 60%, for both conventional and roller-compacted concrete. Tensile behaviour of fibre-reinforced-concrete is estimated in this paper by inverse analysis of bending test results, examining a variety of concrete mixes and steel fibres. A multilinear relationship is proposed which largely eliminates the overestimation problem and can lead to safer designs. [es

Automatic Identification of Subtechniques in Skating-Style Roller Skiing Using Inertial Sensors

Science.gov (United States)

Sakurai, Yoshihisa; Fujita, Zenya; Ishige, Yusuke

2016-01-01

This study aims to develop and validate an automated system for identifying skating-style cross-country subtechniques using inertial sensors. In the first experiment, the performance of a male cross-country skier was used to develop an automated identification system. In the second, eight male and seven female college cross-country skiers participated to validate the developed identification system. Each subject wore inertial sensors on both wrists and both roller skis, and a small video camera on a backpack. All subjects skied through a 3450 m roller ski course using a skating style at their maximum speed. The adopted subtechniques were identified by the automated method based on the data obtained from the sensors, as well as by visual observations from a video recording of the same ski run. The system correctly identified 6418 subtechniques from a total of 6768 cycles, which indicates an accuracy of 94.8%. The precisions of the automatic system for identifying the V1R, V1L, V2R, V2L, V2AR, and V2AL subtechniques were 87.6%, 87.0%, 97.5%, 97.8%, 92.1%, and 92.0%, respectively. Most incorrect identification cases occurred during a subtechnique identification that included a transition and turn event. Identification accuracy can be improved by separately identifying transition and turn events. This system could be used to evaluate each skier’s subtechniques in course conditions. PMID:27049388

Automatic Identification of Subtechniques in Skating-Style Roller Skiing Using Inertial Sensors

Directory of Open Access Journals (Sweden)

Yoshihisa Sakurai

2016-04-01

Full Text Available This study aims to develop and validate an automated system for identifying skating-style cross-country subtechniques using inertial sensors. In the first experiment, the performance of a male cross-country skier was used to develop an automated identification system. In the second, eight male and seven female college cross-country skiers participated to validate the developed identification system. Each subject wore inertial sensors on both wrists and both roller skis, and a small video camera on a backpack. All subjects skied through a 3450 m roller ski course using a skating style at their maximum speed. The adopted subtechniques were identified by the automated method based on the data obtained from the sensors, as well as by visual observations from a video recording of the same ski run. The system correctly identified 6418 subtechniques from a total of 6768 cycles, which indicates an accuracy of 94.8%. The precisions of the automatic system for identifying the V1R, V1L, V2R, V2L, V2AR, and V2AL subtechniques were 87.6%, 87.0%, 97.5%, 97.8%, 92.1%, and 92.0%, respectively. Most incorrect identification cases occurred during a subtechnique identification that included a transition and turn event. Identification accuracy can be improved by separately identifying transition and turn events. This system could be used to evaluate each skier’s subtechniques in course conditions.

Solving the Dial-a-Ride Problem using Genetic algorithms

DEFF Research Database (Denmark)

Bergvinsdottir, Kristin Berg; Larsen, Jesper; Jørgensen, Rene Munk

In the Dial-a-Ride problem (DARP) customers send transportation requests to an operator. A request consists of a specified pickup location and destination location along with a desired departure or arrival time and demand. The aim of DARP is to minimize transportation cost while satisfying custom...... routing problems for the vehicles using a routing heuristic. The algorithm is implemented in Java and tested on publicly available data sets....

MacDonald Dam reconstruction : using roller-compacted concrete

Energy Technology Data Exchange (ETDEWEB)

O' Neil, E. [AMEC Earth and Environmental Ltd., Sydney, NS (Canada)

2007-04-01

Located in Nova Scotia, the MacDonald Dam was commissioned in 1928. The dam consists of a 122 metre-long, 16 metre-high concrete structure comprised of an intake structure, stoplog openings, and a 34 metre-long free-overflow spillway. A 488 metre-long power canal was added as an upgrade in the 1950s. This paper provided details of the roller-compact concrete (RCC) used in the dam's recent rehabilitation following a dam failure analysis in 2003 by Nova Scotia Power Inc. RCC was chosen to help keep the dam's construction project on schedule. The layout and cross-section of the spillway was selected with consideration given to the RCC placing operation. A lift thickness of 0.20 m was selected. A formed ogee crest consisting of conventional reinforced concrete was constructed on top of the RCC. The downstream steps of the spillway were also covered with cast-in-place concrete. A low level sluice was designed to resist the weight of the wet RCC. The design compressive strength of the RCC was 20 MPa. The forms used to support the cast-in-place facing concrete on the upstream face of the dam were constructed full height and were braced back to the downstream face of the existing concrete structure prior to the start of RCC placement. Formwork inserts were placed in the facing concrete as construction progressed. Crack inducers were pre-placed on the forms. Aggregates from a local source were transported to a pug mill as the RCC construction progressed. The RCC was spread into 0.20 m lifts using a small bull-dozer, and the facing concrete was vibrated into the lift below. RCC lifts were compacted using a 9 tonne vibratory drum roller. The RCC placing operation was completed over a period of 10 days. Following the completion of the RCC portion of the dam, the remainder of the cast-in-place concrete was completed. It was concluded that the RCC provided a durable, low-maintenance structure that was completed at a lower price and in a shorter time-frame than

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, For Calendar Year 2007

International Nuclear Information System (INIS)

NSTec Environmental Restoration

2008-01-01

This report provides the results of the semiannual post-closure inspections conducted at the closed Corrective Action Unit (CAU) sites located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2007 and includes inspection and repair activities completed at the following nine CAUs: (1) CAU 400: Bomblet Pit and Five Points Landfill (TTR); (2) CAU 404: Roller Coaster Lagoons and Trench (TTR); (3) CAU 407: Roller Coaster RadSafe Area (TTR); (4) CAU 423: Area 3 Underground Discharge Point, Building 0360 (TTR); (5) CAU 424: Area 3 Landfill Complexes (TTR); (6) CAU 426: Cactus Spring Waste Trenches (TTR); (7) CAU 427: Area 3 Septic Waste Systems 2, 6 (TTR); (8) CAU 453: Area 9 UXO Landfill (TTR); and (9) CAU 487: Thunderwell Site (TTR). In a letter from the Nevada Division of Environmental Protection (NDEP) dated December 5, 2006, NDEP concurred with the request to reduce the frequency of post-closure inspections of CAUs at TTR to an annual frequency. This letter is included in Attachment B. Post-closure inspections were conducted on May 15-16, 2007. All inspections were conducted according to the post-closure plans in the approved Closure Reports. The post-closure inspection plan for each CAU is included in Attachment B, with the exception of CAU 400. CAU 400 does not require post-closure inspections, but inspections of the vegetation and fencing are conducted as a best management practice. The inspection checklists for each site inspection are included in Attachment C, the field notes are included in Attachment D, and the site photographs are included in Attachment E. Vegetation monitoring of CAU 400, CAU 404, CAU 407, and CAU 426 was performed in May 2007, and the vegetation monitoring report is included in Attachment F. Maintenance and/or repairs were performed at CAU 453. Animal burrows observed during the annual inspection at CAU 453 were backfilled on August 1, 2007. At this time, the TTR post-closure site inspections should continue as

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, For Calendar Year 2007

Energy Technology Data Exchange (ETDEWEB)

NSTec Environmental Restoration

2008-06-01

This report provides the results of the semiannual post-closure inspections conducted at the closed Corrective Action Unit (CAU) sites located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2007 and includes inspection and repair activities completed at the following nine CAUs: (1) CAU 400: Bomblet Pit and Five Points Landfill (TTR); (2) CAU 404: Roller Coaster Lagoons and Trench (TTR); (3) CAU 407: Roller Coaster RadSafe Area (TTR); (4) CAU 423: Area 3 Underground Discharge Point, Building 0360 (TTR); (5) CAU 424: Area 3 Landfill Complexes (TTR); (6) CAU 426: Cactus Spring Waste Trenches (TTR); (7) CAU 427: Area 3 Septic Waste Systems 2, 6 (TTR); (8) CAU 453: Area 9 UXO Landfill (TTR); and (9) CAU 487: Thunderwell Site (TTR). In a letter from the Nevada Division of Environmental Protection (NDEP) dated December 5, 2006, NDEP concurred with the request to reduce the frequency of post-closure inspections of CAUs at TTR to an annual frequency. This letter is included in Attachment B. Post-closure inspections were conducted on May 15-16, 2007. All inspections were conducted according to the post-closure plans in the approved Closure Reports. The post-closure inspection plan for each CAU is included in Attachment B, with the exception of CAU 400. CAU 400 does not require post-closure inspections, but inspections of the vegetation and fencing are conducted as a best management practice. The inspection checklists for each site inspection are included in Attachment C, the field notes are included in Attachment D, and the site photographs are included in Attachment E. Vegetation monitoring of CAU 400, CAU 404, CAU 407, and CAU 426 was performed in May 2007, and the vegetation monitoring report is included in Attachment F. Maintenance and/or repairs were performed at CAU 453. Animal burrows observed during the annual inspection at CAU 453 were backfilled on August 1, 2007. At this time, the TTR post-closure site inspections should continue as

Application of Dang Van criterion to rolling contact fatigue in wind turbine roller bearings under elastohydrodynamic lubrication conditions

DEFF Research Database (Denmark)

Cerullo, Michele

2014-01-01

classic Hertzian and elastohydrodynamic lubrication theories have been used to model the pressure distribution acting on the inner raceway and results are compared according to the Dang Van multiaxial fatigue criterion. The contact on the bearing raceway is simulated by substituting the roller...

Are all-terrain vehicle riders willing to pay trail user fees to ride on public lands in the USA?

Science.gov (United States)

Stephanie A. Snyder; Robert A. Smail

2009-01-01

Some public lands in the USA offer opportunities for all-terrain vehicle (ATV) riding, but few charge trail use fees. In a case study in the US state of Wisconsin, the contingent valuation method was used to examine riders' willingness to pay (WTP) to ride on public lands. Information on riders' habits, preferences and responses to a dichotomous choice WTP...

Microstructure and soft magnetic properties of Finemet-type ribbons obtained by twin-roller melt-spinning

International Nuclear Information System (INIS)

Pozo Lopez, G.; Fabietti, L.M.; Condo, A.M.; Urreta, S.E.

2010-01-01

Soft magnetic ribbons of Finemet-type (Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9 ) alloys are synthesized by the twin-roller melt-spinning technique directly from the melt, at tangential wheel speeds of 15, 18, 19 and 20 m/s. The microstructure and the magnetic properties are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), differential thermal analysis (DTA), thermo-gravimetric analysis (TGA) and hysteresis loops measurements. Samples cooled at 20 m/s are amorphous, while those quenched at lower wheel speeds are partially crystalline. All samples studied present saturation magnetization values (150-160 A m 2 /kg) higher than the commercial Finemet alloys (∼135 A m 2 /kg), obtained by controlled crystallization of amorphous single-roller melt-spun alloys. Optimal soft magnetic properties - σ S =(154±8) A m 2 /kg and H C =(6.9±0.9) A/m - are found in samples quenched at 19 m/s, consisting of size-distributed bcc Fe-Si nanograins (∼18 nm in average) embedded in an amorphous residual matrix. A minority nanocrystalline magnetic phase (≤10 nm) is also detected.

Performance of integrated systems of automated roller shade systems and daylight responsive dimming systems

Energy Technology Data Exchange (ETDEWEB)

Park, Byoung-Chul; Choi, An-Seop; Jeong, Jae-Weon [Department of Architectural Engineering, Sejong University, Kunja-Dong, Kwangjin-Gu, Seoul (Korea, Republic of); Lee, Eleanor S. [Building Technologies Department, Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

2011-03-15

Daylight responsive dimming systems have been used in few buildings to date because they require improvements to improve reliability. The key underlying factor contributing to poor performance is the variability of the ratio of the photosensor signal to daylight workplane illuminance in accordance with sun position, sky condition, and fenestration condition. Therefore, this paper describes the integrated systems between automated roller shade systems and daylight responsive dimming systems with an improved closed-loop proportional control algorithm, and the relative performance of the integrated systems and single systems. The concept of the improved closed-loop proportional control algorithm for the integrated systems is to predict the varying correlation of photosensor signal to daylight workplane illuminance according to roller shade height and sky conditions for improvement of the system accuracy. In this study, the performance of the integrated systems with two improved closed-loop proportional control algorithms was compared with that of the current (modified) closed-loop proportional control algorithm. In the results, the average maintenance percentage and the average discrepancies of the target illuminance, as well as the average time under 90% of target illuminance for the integrated systems significantly improved in comparison with the current closed-loop proportional control algorithm for daylight responsive dimming systems as a single system. (author)

Gust Wind Effects on Stability and Ride Quality of Actively Controlled Maglev Guideway Systems

Directory of Open Access Journals (Sweden)

Dong-Ju Min

2017-01-01

Full Text Available The purpose of this paper is to present a framework to analyze the interaction between an actively controlled magnetic levitation vehicle and a guideway structure under gusty wind. The equation of motion is presented for a 30-dof maglev vehicle model consisting of one cabin and four bogies. In addition, a lateral electromagnetic suspension (EMS system is introduced to improve the running safety and ride quality of the maglev vehicle subjected to turbulent crosswind. By using the developed simulation tools, the effects of various parameters on the dynamic response of the vehicle and guideway are investigated in the case of the UTM maglev vehicle running on a simply supported guideway and cable-stayed guideway. The simulation results show that the independent lateral EMS and associated control scheme are definitely helpful in improving the running safety and ride quality of the vehicle under gusty wind. In the case of the cable-stayed guideway, at low wind speed, vehicle speed is the dominant factor influencing the dynamic responses of the maglev vehicle and the guideway, but at wind speed over 10 m/s, wind becomes the dominant factor. For the ride quality of the maglev vehicle, wind is also the most influential factor.

The effect of cannabis on regular cannabis consumers' ability to ride a bicycle.

Science.gov (United States)

Hartung, Benno; Schwender, Holger; Roth, Eckhard H; Hellen, Florence; Mindiashvili, Nona; Rickert, Annette; Ritz-Timme, Stefanie; Grieser, Almut; Monticelli, Fabio; Daldrup, Thomas

2016-05-01

To assess the effects of cannabis on the ability required to ride a bicycle, repetitive practical cycling tests and medical examinations were carried out before and after inhalative consumption of cannabis. A maximum of three joints with body weight-adapted THC content (300 μg THC per kg body weight) could be consumed by each test subject. Fourteen regular cannabis-consuming test subjects were studied (12 males, 2 females). In summary, only a few driving faults were observed even under the influence of very high THC concentrations. A defined THC concentration that leads to an inability to ride a bicycle cannot be presented. The test subjects showed only slight distinctive features that can be documented using a medical test routinely run for persons under suspicion of driving under the influence of alcohol or drugs.

Low-Voltage Ride-Through Operation of Power Converters in Grid-Interactive Microgrids by Using Negative-Sequence Droop Control

DEFF Research Database (Denmark)

Zhao, Xin; Guerrero, Josep M.; Savaghebi, Mehdi

2017-01-01

of the utility grid during grid faults. In this paper, a LVRT control strategy based on positive/negative sequence droop control is proposed for grid-interactive MGs to ride-through voltage sags with not only inductive/resistive, but also complex line impedance. By using the proposed control strategy, MGs can......Due to the increasing penetration level of microgrids (MGs), it becomes a critical issue for MGs to help sustaining power system stability. Therefore, ancillary services, such as the low-voltage ride-through (LVRT) capability should be incorporated in MGs in order to guarantee stable operation...... support the grid voltage, make profits, and also ride-through the voltage dip during the whole fault period. A two layer hierarchical control strategy is proposed in this paper. The primary controller consists of voltage and current inner loops, a conventional droop control and a virtual impedance loop...

Low Voltage Ride-Through Capability Solutions for Permanent Magnet Synchronous Wind Generators

Directory of Open Access Journals (Sweden)

Victor F. Mendes

2016-01-01

Full Text Available Due to the increasing number of wind power plants, several countries have modified their grid codes to include specific requirements for the connection of this technology to the power system. One of the requirements is the ride-through fault capability (RTFC, i.e., the system capability to sustain operation during voltage sags. In this sense, the present paper intends to investigate the behavior of a full-converter wind generator with a permanent magnet synchronous machine during symmetrical and asymmetrical voltage sags. Two solutions to improve the low voltage ride-through capability (LVRT of this technology are analyzed: discharging resistors (brake chopper and resonant controllers (RCs. The design and limitations of these solutions and the others proposed in the literature are discussed. Experimental results in a 34 kW test bench, which represents a scaled prototype of a real 2 MW wind conversion system, are presented.

Occupational exposure to unburnt tobacco and potential risk of toxic optic neuropathy: A cross-sectional study among beedi rollers in selected rural areas of coastal Karnataka, India.

Directory of Open Access Journals (Sweden)

Soujanya Kaup

Full Text Available Beedi also known as poor man's cigarette is manufactured in almost all major states of India. Beedi workers are exposed to various health risks. There is an increased risk of systemic absorption of tobacco through skin and mucous membrane. The optic nerve is susceptible to damage from several toxic substances including tobacco. This group of disorders is known as toxic optic neuropathy (TON. The association of TON with occupational exposure to unburnt tobacco in beedi rollers has not been explored.Among the beedi rollers in Mangaluru and Bantwal talukas of Dakshina Kannada District, Karnataka, India: to assess the magnitude of potential TON utilizing colour vision and contrast sensitivity as screening tools and to identify the demographic, biological and occupational factors associated with potential TON.A community-based cross-sectional study was conducted from April-Sept 2016 in Mangaluru and Bantwal talukas, of Dakshina Kannada district, Karnataka. Beedi rollers from twelve villages (six from each taluka were included. In each of the selected villages, the investigators identified beedi collection centres and all the eligible beedi rollers were included in the study till the required number of beedi rollers for that village was achieved. Participants were screened at the study site for visual acuity, colour vision and contrast sensitivity and those with abnormal colour and contrast sensitivity in the presence of good visual acuity were considered to have potential TON.A total of 377 beedi rollers were approached; of which 365 consented to take part in the study (response rate: 96.81%. Women constituted the majority of the participants (n = 338, 92.6%. Based on the screening criteria, the prevalence of potential TON was 17.5% (n = 64, 95% CI: 13.5-21.9. On multiple logistic regression analysis, duration of beedi rolling (Adj OR: 1.061; 95% CI 1.015-1.109, p = 0.009, advancing age (Adj OR: 1.096; 95% CI 1.058-1.136, p<0.001 and presence of

The effect of therapeutic horseback riding on balance in community-dwelling older adults: a pilot study.

Science.gov (United States)

Homnick, Tamara D; Henning, Kim M; Swain, Charlene V; Homnick, Douglas N

2015-02-01

Equine assisted activities (hippotherapy and therapeutic riding) improve balance in patients with disabilities such as cerebral palsy, but have not been systematically studied in older adults, at risk of falls due to balance deficits. We conducted a 10-week, single blind, controlled trial of the effect of a therapeutic horseback riding course on measures of balance in community-dwelling adults 65 years and older. Nine riders and six controls completed the trial. Controls were age matched to riders and all participants were recruited from the local community. Both groups showed improvements in balance during the trial, but did not reach statistical significance. Sample size was small, participants had relatively high initial balance scores, and controls tended to increase their physical activities, likely influencing outcomes. No adverse events occurred and the supervised therapeutic riding program appeared to be a safe and effective form of exercise to improve balance in older adults. A power analysis was performed to estimate numbers of participants needed for a larger study. © The Author(s) 2012.

[Sports injuries in children. Epidemiologic study].

Science.gov (United States)

Du Boullay, C T; Bardier, M; Cheneau, J; Bortolasso, J; Gaubert, J

1984-01-01

Among 49 000 cases of infantile emergencies which were received in the BUCI (Bloc d'urgence chirurgical infantile: surgical infantile emergency unit), 5 546 were sport traumas. At an early age, they were caused by outdoor plays; during adolescence, the main cases were caused by team sports. Males are predominant. The number of cases has been regularly progressing, particularly since 1976. The fashion in sports is influenced by médias (i.e. skate board), and can be opposed to the continuous practice of popular sports (swimming, ball games, bycicle. There are winter, summer, school timed sports (the latter being influenced by the sportive scholar associations). The most frequent sports are cycling, football playing, swimming and horse riding, athleticism skating, Other are occasionnal. Changes in sport fashions, female increasing participation, such as horse riding and skating, democratisation (skiing, riding), the worsening of traumas; the pathology concerning bystanders, are described. Cranial and peripheric pathology are dominant. Trunk traumas are scarce but severe. Each sport has an elective pathologic localisation. Injury mechanisms are found, such as stirrup, saddle, ski baton pathology. There is traumatologic similarities; skate board and roller skating; judo and atheleticism; cycling and horse riding. Sport in children is not a replica of the one among adults. Riding a bike is not cycling. Some sports are dangerous: cycling, horse riding, rugby. A traumatological outline is revealed. Preventive measures should be taken. The socio-economical cost is heavy.

Using forecast information for storm ride-through control

DEFF Research Database (Denmark)

Barahona Garzón, Braulio; Trombe, Pierre-Julien; Vincent, Claire Louise

2013-01-01

Using probabilistic forecast information in control algorithms can improve the performance of wind farms during periods of extreme winds. This work presents a wind farm supervisor control concept that uses probabilistic forecast information to ride-through a storm with softer ramps of power. Wind...... speed forecasts are generated with a statistical approach (i.e. time series models). The supervisor control is based on a set of logical rules that consider point forecasts and predictive densities to ramp-down the power of the wind farm before the storm hits. The potential of this supervisor control...

Alred Roller – An Innovator and a Traditionalist

Directory of Open Access Journals (Sweden)

Zavarský Ján

2017-12-01

Full Text Available This study focuses on the scenographer Alfred Roller (1864–1935 and his productions of Wagner’s musical dramas, with emphasis on Tristan and Isolde and Parsifal. It places Roller’s aesthetics in a historical, aesthetic, and artistic context, points to his inspiration by the Swiss scenography reformer Adolphe Appia, and cooperation with the music composer and conductor Gustav Mahler in the Vienna Court Opera. The text analyses the specifics of Roller’s scenography, which diverged from illusive stage and used light work as an important production principle. It concludes with a summary of the effect of Roller’s aesthetics on Ľudovít Hradský, the first leader of the production team at the Slovak National Theatre (1923–1928. The visual aspects of the Slovak National Theatre’s productions in that period were strongly inspired by expressionism and Art Nouveau, which were typical of German theatre at that time.

Abrasion Resistance and Mechanical Properties of Waste-Glass-Fiber-Reinforced Roller-compacted Concrete

Science.gov (United States)

Yildizel, S. A.; Timur, O.; Ozturk, A. U.

2018-05-01

The potential use of waste glass fibers in roller-compacted concrete (RCC) was investigated with the aim to improve its performance and reduce environmental effects. The research was focused on the abrasion resistance and compressive and flexural strengths of the reinforced concrete relative to those of reference mixes without fibers. The freeze-thaw resistance of RCC mixes was also examined. It was found that the use of waste glass fibers at a rate of 2 % increased the abrasion resistance of the RCC mixes considerably.

Aging effect on plasma metabolites and hormones concentrations in riding horses

Directory of Open Access Journals (Sweden)

K. Kawasumi

2015-11-01

Full Text Available Age effects on plasma metabolites, hormone concentrations, and enzyme activities related to energy metabolism were investigated in 20 riding horses. Animals were divided into two groups: Young (3-8 years and aged (11-18 years. They were clinically healthy, and not obese. Plasma adiponectin (ADN concentrations in aged horses were significantly lower than those in young horses (mean±SE, 6.5±1.3 μg mL-1 vs, 10.9±1.7 μg mL-1, Mann-Whitney U test, respectively; P=0.0233. Plasma non-esterified fatty acid levels and Insulin and malondialdehyde concentrations in aged group tended to increase compared to those in young group although there were not significant differences statistically. In aged group, malate dehydrogenase/lactate dehydrogenase (M/L ratio, which is considered an energy metabolic indicator, did not change significantly compared to that in young group. Present data suggest that aging may negatively affect nutrition metabolism, but not induce remarkable changes in M/L ratio in riding horses.

Ride Your Luck! A Field Experiment on Lottery-Based Incentives for Compliance

NARCIS (Netherlands)

M. Fabbri (Marco); P.N. Barbieri (Paolo); M. Bigoni (Maria)

2016-01-01

textabstractWe designed a natural-field experiment in the context of local public transportation to test whether rewards in the form of lottery prizes coupled with traditional sanctions efficiently reduce free-riding. We organized a lottery in a medium-size Italian city the participation in which is

Cognition and relative importance underlying consumer valuation of park-and-ride facilities

NARCIS (Netherlands)

Bos, D.M.; Molin, E.J.E.; Timmermans, H.J.P.; vd Heijden, R.E.C.M.

2003-01-01

Results are reported of a study designed to identify the cognitive constructs underlying the valuation of park-and-ride (P&R) facilities and to measure the relative importance attached to the attributes of such facilities. Results show that the reliability of public transport is quite important.

High-throughput creation of micropatterned PDMS surfaces using microscale dual roller casting

International Nuclear Information System (INIS)

DiBartolomeo, Franklin J; Ge, Ning; Trinkle, Christine A

2012-01-01

This work introduces microscale dual roller casting (MDRC), a novel high-throughput fabrication method for creating continuous micropatterned surfaces using thermosetting polymers. MDRC utilizes a pair of rotating, heated cylindrical molds with microscale surface patterns to cure a continuous microstructured film. Using unmodified polydimethylsiloxane as the thermosetting polymer, we were able to create optically transparent, biocompatible surfaces with submicron patterning fidelity. Compared to other roll-to-roll fabrication processes, this method offers increased flexibility in the types of materials and topography that can be generated, including dual-sided patterning, embedded materials and tunable film thickness. (paper)

Influence of ambient moisture on the compaction behavior of microcrystalline cellulose powder undergoing uni-axial compression and roller-compaction: a comparative study using near-infrared spectroscopy.

Science.gov (United States)

Gupta, Abhay; Peck, Garnet E; Miller, Ronald W; Morris, Kenneth R

2005-10-01

This study evaluates the effect of variation in the ambient moisture on the compaction behavior of microcrystalline cellulose (MCC) powder. The study was conducted by comparing the physico-mechanical properties of, and the near infrared (NIR) spectra collected on, compacts prepared by roller compaction with those collected on simulated ribbons, that is, compacts prepared under uni-axial compression. Relative density, moisture content, tensile strength (TS), and Young modulus were used as key sample attributes for comparison. Samples prepared at constant roller compactor settings and feed mass showed constant density and a decrease in TS with increasing moisture content. Compacts prepared under uni-axial compression at constant pressure and compact mass showed the opposite effect, that is, density increased while TS remained almost constant with increasing moisture content. This suggests difference in the influence of moisture on the material under roller compaction, in which the roll gap (i.e., thickness and therefore density) remains almost constant, vs. under uni-axial compression, in which the thickness is free to change in response to the applied pressure. Key sample attributes were also related to the NIR spectra using multivariate data analysis by the partial least squares projection to latent structures (PLS). Good agreement was observed between the measured and the NIR-PLS predicted values for all key attributes for both, the roller compacted samples as well as the simulated ribbons. Copyright (c) 2005 Wiley-Liss, Inc. and the American Pharmacists Association

Low Voltage Ride-Through Capability of a Single-Stage Single-Phase Photovoltaic System Connected to the Low-Voltage Grid

DEFF Research Database (Denmark)

Yang, Yongheng; Blaabjerg, Frede

2013-01-01

The progressively growing of single-phase photovoltaic (PV) systems makes the Distribution System Operators (DSO) to update or revise the existing grid codes in order to guarantee the availability, quality and reliability of the electrical system. It is expected that the future PV systems connected...... to the low-voltage grid will be more active with functionalities of low voltage ride-through (LVRT) and the grid support capability, which is not the case today. In this paper, the operation principle is demonstrated for a single-phase grid-connected PV system in low voltage ride through operation in order...... to map future challenges. The system is verified by simulations and experiments. Test results show that the proposed power control method is effective and the single-phase PV inverters connected to low-voltage networks are ready to provide grid support and ride-through voltage fault capability...

The high-riding superior aortic recess of the pericardium: MRI visualization in a child

International Nuclear Information System (INIS)

Cohen, Mervyn; Johnson, Tiffanie; Hoyer, Mark

2005-01-01

We report a 4-year-old child with a high-riding superior aortic recess of the pericardium, initially misdiagnosed as a possible vascular malformation. The anatomy of the pericardial recesses is reviewed. (orig.)

Developing a model-based decision support system for call-a-ride paratransit service problems.

Science.gov (United States)

2011-02-01

Paratransit is the transportation service that supplements larger public transportation : systems by providing individualized rides without fixed routes or timetables. In 1990, : the Americans with Disabilities Act (ADA) was passed which allows passe...

Justification of the Shape of a Non-Circular Cross-Section for Drilling With a Roller Cutter

Science.gov (United States)

Buyalich, Gennady; Husnutdinov, Mikhail

2017-11-01

The parameters of the shape of non-circular cross-section affect not only the process of blasting, but also the design of the tool and the process of drilling as well. In the conditions of open-pit mining, it is reasonable to use a roller cutter to produce a non-circular cross-section of blasting holes. With regard to the roller cutter, the impact of the cross-section shape on the oscillations of the axial force arising upon its rotation is determined. It is determined that a polygonal shape with rounded comers of the borehole walls connections and their convex shape, which ensures a smaller range of the total axial force and the torque deflecting the bit from the axis of its rotation is the rational form of the non-circular cross-section of the borehole in terms of bit design. It has been shown that the ratio of the number of cutters to the number of borehole corners must be taken into account when justifying the shape of the cross-section, both from the point of view of the effectiveness of the explosion action and from the point of view of the rational design of the bit.

Identifying the psychological determinants of risky riding: an application of an extended Theory of Planned Behaviour.

Science.gov (United States)

Chorlton, Kathryn; Conner, Mark; Jamson, Samantha

2012-11-01

The Theory of Planned Behaviour (TPB) plus moral norms, anticipated regret, past behaviour, self-identity and perceived susceptibility was applied to predicting motorcyclists' intention to ride above the speed limit and ride at inappropriate speeds. Past behaviour, control beliefs, attitudes, moral norm, normative beliefs, age and self-identity explained 60% of the variance in motorcyclists' intention to exceed the speed limit on motorways (N=1381). A total of 62% of the variance in motorcyclists' intention to really go for it on rural roads was accounted for, with past behaviour, attitudes, control beliefs, age, normative beliefs, anticipated regret, self-identity, behavioural beliefs and training status being significant (N=1116). Finally, attitudes, past behaviour, control beliefs, moral norm, anticipated regret, behavioural beliefs, normative beliefs, engine size and self-identity explained 57% of the variance in motorcyclists' intention to ride faster than felt safe in order to keep up with the group (N=1940). The belief-based measures also successfully differentiated between those who intended to speed and those who did not. Theoretical and practical implications of the findings are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

VIRTUAL MODEL OF A ROLLER CONVEYOR INTEGRATED INTO A LOGISTIC FLOW

Directory of Open Access Journals (Sweden)

POPESCU Adrian

2015-11-01

Full Text Available In this article is presented, with the help of graphics, a logistic flow for palletizing and wrapping operations. The loaded pallets are transported by means of a roller conveyor. Creating the virtual model for the conveyer allows us to emphasize the compatibility elements between on the one hand the mechanical assemblies of the flow components and on the other hand the subassemblies of the conveyer structure. The paper has focused on the presentation of the conveyor specific assembly and how are placed the sensors on the mechanical structure of the conveyor. Finally, the main working phases are graphically presented within the flow, highlighting the loaded pallet positions in the flow.

The Effects of Hippotherapy and a Horse Riding Simulator on the Balance of Children with Cerebral Palsy

Science.gov (United States)

Lee, Chae-Woo; Kim, Seong Gil; Na, Sang Su

2014-01-01

[Purpose] We with respect to their effects on the compared hippotherapy with a horseback riding simulator (JOBA, Panasonic Inc. JP) static and dynamic balance of children with cerebral palsy (CP). [Subjects and Methods] Twenty-six children were randomly divided into two groups: a hippotherapy group that included 13 children, and a horseback riding simulator (JOBA, Panasonic Inc., Japan) group, which was also composed of 13 children. The two groups participated in 1 hour of exercise per day, 3 times a week, for 12 weeks. The subjects’ static balance ability was measured using BPM (software 5.3, SMS Healthcare Inc., UK) as the center of pressure sway length while standing for 30 seconds with their eyes open and looking to the front. Dynamic balance ability was measured using the PBS (Pediatric Balance Scale). [Results] Both groups showed significant improvements in static and dynamic balance but significant differences between the two groups were not found. [Conclusion] The horseback riding simulator could be a useful alternative to hippotherapy for the improvement of static and dynamic balance of children with CP. PMID:24707098

Use of flyash in roller compacted concrete for Ghatghar pumped storage scheme in Maharashtra

Energy Technology Data Exchange (ETDEWEB)

Damani, R.L.; Kshirsagar, S.L.; Narkhede, C.L. [MERI, Nashik (India)

2003-07-01

The paper described the use of 'Roller Compacted Concrete' (RCE) in which about 60% of the cement will be replaced by fly ash for construction of two storage dams - Upper dam and Lower dam in the Thane district of India. These are part of the Ghatghar Pumped Storage Scheme to generate hydropower. Fly ash from Eklahare and Dahav thermal power plant and processed fly ash, Pozzocrete 63 and 83b grade, all proved suitable for the RCC mix. 1 tab.

Terror Park: A future theme park in 2100

OpenAIRE

Wright, Daniel

2017-01-01

In the future, tourism and entertainment could be displayed as spectacles of horror, where consumers are offered and opportunity to revisit the tragedies of the past. Current displays of death where the past is exhibited and consumed as fun, scary and as entertainment productions are widespread. The movie industry provides horror to all ages, children can be exposed to the goulash past in various forms, such as the popular book series ‘Horrible Histories’. Theme parks, rides and roller-coaste...

Solving the Dial-a-Ride Problem using Genetic Algorithms

DEFF Research Database (Denmark)

Jørgensen, Rene Munk; Larsen, Jesper; Bergvinsdottir, Kristin Berg

2007-01-01

In the Dial-a-Ride problem (DARP), customers request transportation from an operator. A request consists of a specified pickup location and destination location along with a desired departure or arrival time and capacity demand. The aim of DARP is to minimize transportation cost while satisfying ...... routing problems for the vehicles using a routing heuristic. The algorithm is implemented in Java and tested on publicly available data sets. The new solution method has achieved solutions comparable with the current state-of-the-art methods....

An adaptive Phase-Locked Loop algorithm for faster fault ride through performance of interconnected renewable energy sources

DEFF Research Database (Denmark)

Hadjidemetriou, Lenos; Kyriakides, Elias; Blaabjerg, Frede

2013-01-01

Interconnected renewable energy sources require fast and accurate fault ride through operation in order to support the power grid when faults occur. This paper proposes an adaptive Phase-Locked Loop (adaptive dαβPLL) algorithm, which can be used for a faster and more accurate response of the grid...... side converter control of a renewable energy source, especially under fault ride through operation. The adaptive dαβPLL is based on modifying the control parameters of the dαβPLL according to the type and voltage characteristic of the grid fault with the purpose of accelerating the performance...

RIDES: Robust Intrusion Detection System for IP-Based Ubiquitous Sensor Networks.

Science.gov (United States)

Amin, Syed Obaid; Siddiqui, Muhammad Shoaib; Hong, Choong Seon; Lee, Sungwon

2009-01-01

The IP-based Ubiquitous Sensor Network (IP-USN) is an effort to build the "Internet of things". By utilizing IP for low power networks, we can benefit from existing well established tools and technologies of IP networks. Along with many other unresolved issues, securing IP-USN is of great concern for researchers so that future market satisfaction and demands can be met. Without proper security measures, both reactive and proactive, it is hard to envisage an IP-USN realm. In this paper we present a design of an IDS (Intrusion Detection System) called RIDES (Robust Intrusion DEtection System) for IP-USN. RIDES is a hybrid intrusion detection system, which incorporates both Signature and Anomaly based intrusion detection components. For signature based intrusion detection this paper only discusses the implementation of distributed pattern matching algorithm with the help of signature-code, a dynamically created attack-signature identifier. Other aspects, such as creation of rules are not discussed. On the other hand, for anomaly based detection we propose a scoring classifier based on the SPC (Statistical Process Control) technique called CUSUM charts. We also investigate the settings and their effects on the performance of related parameters for both of the components.

Chaotic Dynamics of Cage Behavior in a High-Speed Cylindrical Roller Bearing

Directory of Open Access Journals (Sweden)

Long Chen

2016-01-01

Full Text Available This paper presents a mathematical model to investigate the nonlinear dynamic behavior of cage in high-speed cylindrical bearing. Variations of cage behavior due to varying cage eccentricity and cage guidance gap are observed. Hydrodynamic behavior in cage contacts is taken into consideration for a more realistic calculation of acting forces owing to high working speed. Analysis of real-time cage dynamic behavior on radial plane is carried out using chaos theory based on the theoretical and mathematical model established in the paper. The analytical results of this paper provide a solid foundation for designing and manufacturing of high-speed cylindrical roller bearing.

Description and validation of ERAD: An atmospheric dispersion model for high explosive detonations

Energy Technology Data Exchange (ETDEWEB)

Boughton, B.A.; DeLaurentis, J.M.

1992-10-01

The Explosive Release Atmospheric Dispersion (ERAD) model is a three-dimensional numerical simulation of turbulent atmospheric transport and diffusion. An integral plume rise technique is used to provide a description of the physical and thermodynamic properties of the cloud of warm gases formed when the explosive detonates. Particle dispersion is treated as a stochastic process which is simulated using a discrete time Lagrangian Monte Carlo method. The stochastic process approach permits a more fundamental treatment of buoyancy effects, calm winds and spatial variations in meteorological conditions. Computational requirements of the three-dimensional simulation are substantially reduced by using a conceptualization in which each Monte Carlo particle represents a small puff that spreads according to a Gaussian law in the horizontal directions. ERAD was evaluated against dosage and deposition measurements obtained during Operation Roller Coaster. The predicted contour areas average within about 50% of the observations. The validation results confirm the model`s representation of the physical processes.

Measuring the operational efficiency of individual theme park attractions.

Science.gov (United States)

Kim, Changhee; Kim, Soowook

2016-01-01

This study assesses the operation efficiency of theme park attractions using the data envelopment analysis, utilizing actual data on 15 attractions at Samsung Everland located in Yongin-si, Republic of Korea. In particular, this study identifies crowding and waiting time as one of the main causes of visitor's satisfaction, and analyzes the efficiency of individual attractions in terms of waiting time. The installation area, installation cost, and annual repair cost are set as input factors and the number of annual users and customer satisfaction as output factors. The results show that the roller coaster-type attractions were less efficient than other types of attractions while rotating-type attractions were relatively more efficient. However, an importance performance analysis on individual attraction's efficiency and satisfaction showed that operational efficiency should not be the sole consideration in attraction installation. In addition, the projection points for input factors for efficient use of attractions and the appropriate reference set for benchmarking are provided as guideline for attraction efficiency management.

An Artificial-Gravity Space-Settlement Ground-Analogue Design Concept

Science.gov (United States)

Dorais, Gregory A.

2016-01-01

The design concept of a modular and extensible hypergravity facility is presented. Several benefits of this facility are described including that the facility is suitable as a full-scale artificial-gravity space-settlement ground analogue for humans, animals, and plants for indefinite durations. The design is applicable as an analogue for on-orbit settlements as well as those on moons, asteroids, and Mars. The design creates an extremely long-arm centrifuge using a multi-car hypergravity vehicle travelling on one or more concentric circular tracks. This design supports the simultaneous generation of multiple-gravity levels to explore the feasibility and value of and requirements for such space-settlement designs. The design synergizes a variety of existing technologies including centrifuges, tilting trains, roller coasters, and optionally magnetic levitation. The design can be incrementally implemented such that the facility can be operational for a small fraction of the cost and time required for a full implementation. Brief concept of operation examples are also presented.

Closure Report for Corrective Action Unit 426: Cactus Spring Waste Trenches, Tonopah Test Range, Nevada

Energy Technology Data Exchange (ETDEWEB)

Dave Madsen

1998-08-01

This Closure Report provides the documentation for closure of the Cactus Spring Waste Trenches Corrective Action Unit (CAU) 426. The site is located on the Tonopah Test Range, approximately 225 kilometers northwest of Las Vegas, NV. CAU 426 consists of one corrective action site (CAS) which is comprised of four waste trenches. The trenches were excavated to receive solid waste generated in support of Operation Roller Coaster, primary the Double Tracks Test in 1963, and were subsequently backfilled. The Double Tracks Test involved use of live animals to assess the biological hazards associated with the nonnuclear detonation of plutonium-bearing devices. The Nevada Division of Environmental Protection approved Corrective Action Plan (CAP)which proposed ''capping'' methodology. The closure activities were completed in accordance with the approved CAP and consisted of constructing an engineered cover in the area of the trenches, constructing/planting a vegetative cover, installing a perimeter fence and signs, implementing restrictions on future use, and preparing a Post-Closure Monitoring Plan.

Energy

CERN Document Server

Robertson, William C

2002-01-01

Confounded by kinetic energy? Suspect that teaching about simple machines isn t really so simple? Exasperated by electricity? If you fear the study of energy is beyond you, this entertaining book will do more than introduce you to the topic. It will help you actually understand it. At the book s heart are easy-to-grasp explanations of energy basics work, kinetic energy, potential energy, and the transformation of energy and energy as it relates to simple machines, heat energy, temperature, and heat transfer. Irreverent author Bill Robertson suggests activities that bring the basic concepts of energy to life with common household objects. Each chapter ends with a summary and an applications section that uses practical examples such as roller coasters and home heating systems to explain energy transformations and convection cells. The final chapter brings together key concepts in an easy-to-grasp explanation of how electricity is generated. Energy is the second book in the Stop Faking It! series published by NS...

Therapeutic Effects of Mechanical Horseback Riding on Gait and Balance Ability in Stroke Patients

Science.gov (United States)

Han, Jun Young; Kim, Shin Kyoung; Chung, Jin Sang; Lee, Hyun-Cheol; Lim, Jae Kuk; Lee, Jiwon; Park, Kawn Yong

2012-01-01

Objective To investigate the therapeutic effects of mechanical horseback riding for gait and balance parameters in post-stroke patients. Method This study was a non randomized prospective positive-controlled trial over a 12 week period. From May 2011 to October 2011, 37 stroke patients were recruited from our outpatient clinic and divided into two groups. The control group received the conventional physiotherapy while the intervention group received the conventional physiotherapy along with mechanical horseback riding therapy for 12 weeks. Outcome measurements of gait included the Functional Ambulation Category (FAC) and gait part of the Performance Oriented Mobility Assessment (G-POMA) while those of balance included the Berg Balance Scale (BBS) and the balance part of the Performance Oriented Mobility Assessment (B-POMA). These measurements were taken before and after treatment. Results There were no significant differences in the baseline characteristics and initial values between the two groups. When comparing baseline and 12 weeks post treatment in each group, the intervention group showed significant improvement on BBS (39.9±5.7 → 45.7±4.8, p=0.001) and B-POMA (10.4±2.6 → 12.6±2.1, p=0.001), but significant improvement on gait parameters. When comparing the groups, the dynamic balance category of BBS in post treatment showed significant difference (p=0.02). Conclusion This study suggests that mechanical horseback riding therapy may be an effective treatment tool for enhancing balance in adults with stroke. PMID:23342307

Magneto-rheological suspensions for improving ground vehicle's ride comfort, stability, and handling

Science.gov (United States)

Ahmadian, Mehdi

2017-10-01

A state-of-the-art discussion on the applications of magneto-rheological (MR) suspensions for improving ride comfort, handling, and stability in ground vehicles is discussed for both road and rail applications. A historical perspective on the discovery and engineering development of MR fluids is presented, followed by some of the common methods for modelling their non-Newtonian behaviour. The common modes of the MR fluids are discussed, along with the application of the fluid in valve mode for ground vehicles' dampers (or shock absorbers). The applications span across nearly all road vehicles, including automobiles, trains, semi-trucks, motorcycles, and even bicycles. For each type of vehicle, the results of some of the past studies is presented briefly, with reference to the originating study. It is discussed that Past experimental and modelling studies have indicated that MR suspensions provide clear advantages for ground vehicles that far surpasses the performance of passive suspension. For rail vehicles, the primary advantage is in terms of increasing the speed at which the onset of hunting occurs, whereas for road vehicles - mainly automobiles - the performance improvements are in terms of a better balance between vehicle ride, handling, and stability. To further elaborate on this point, a single-suspension model is used to develop an index-based approach for studying the compromise that is offered by vehicle suspensions, using the H2 optimisation approach. Evaluating three indices based on the sprung-mass acceleration, suspension rattlespace, and tyre deflection, it is clearly demonstrated that MR suspensions significantly improve road vehicle's ride comfort, stability, and handling in comparison with passive suspensions. For rail vehicles, the simulation results indicate that using MR suspensions with an on-off switching control can increase the speed at which the on-set of hunting occurs by as much as 50% to more than 300%.

Effects of Cardinal Direction on Distribution and Populational Dynamism of Oak Leaf Roller (Tortrix viridana L. on Quercus infectoria Oliv. and Q. libani Lindl.

Directory of Open Access Journals (Sweden)

mohammadreza zargaran

2018-01-01

Full Text Available Introduction Various pests attack oak trees and in most cases heavily damage them. The European oak leaf roller is one of the important oak pests in some provinces of the Zagros, and it is an important pest of oak forests in some European and North African countries, as well as in Iraq and other regions of Iran. In Iran, it is scattered in the Zagros oak forests, especially in Kohkiluyeh and Boyer Ahmad, Lorestan, Chahar Mahal and Bakhtiari, Fars, and West Azarbaijan Provinces. Repeated removal of oak leaves, particularly by herbivores such as T. viridana in spring, reduces stored photosynthates in trees leading to their decreased diametrical growth. Materials and Methods The Ghabre-Hossein region (Piranshahr was selected as the field operations region because it is one of the most important infestation centers of the European oak leaf roller in the oak forests of West-Azerbaijan. The research was carried out in two consecutive years. Samples of larval instars were taken in early May. Since the sample plot in sampling methods can be points or lines (transects, the four cardinal directions were selected in this study and transects at 100 m intervals were located in each direction.To reduce sampling error, Aleppo (Quercus infectoria and Lebanon (Q. libani oak trees were selected for measurements that were similar in appearance and almost uniform with crowns or trunks aligned along the transects. In each studied tree, four suitable branches were selected (one in each cardinal direction, and the number of larvae from the tip of each branch to a length of 50 cm inwards was counted and recorded in forms prepared beforehand. Considering studies that were carried out regarding the biology of the pest, the larvae were counted in mid-May when all larvae were in their last (fifth instar. In all, 30 Aleppo and 30 Lebanon oak trees were selected in each cardinal direction, and four branches in each direction of these trees were measured. The survey method

Assessment of Real-Time Compaction Quality Test Indexes for Rockfill Material Based on Roller Vibratory Acceleration Analysis

Directory of Open Access Journals (Sweden)

Tianbo Hua

2018-01-01

Full Text Available Compaction quality is directly related to the structure and seepage stability of a rockfill dam. To timely and accurately test the compaction quality of the rockfill material, four real-time test indexes were chosen to characterize the soil compaction degree based on the analysis of roller vibratory acceleration, including acceleration peak value (ap, acceleration root mean square value (arms, crest factor value (CF, and compaction meter value (CMV. To determine which of these indexes is the most appropriate, a two-part field compaction experiment was conducted using a vibratory roller in different filling zones of the dam body. Data on rolling parameters, real-time test indexes, and compaction quality indexes were collected to perform statistical regression analyses. Combined with the spectrum analysis of the acceleration signal, it was found that the CF index best characterizes the compaction degree of the rockfill material among the four indexes. Furthermore, the quantitative relations between the real-time index and compaction quality index were established to determine the control criterion of CF, which can instruct the site work of compaction quality control in the rockfill rolling process.

Adaptive Technology Application for Vibration-Based Diagnostics of Roller Bearings on Industrial Plants

Directory of Open Access Journals (Sweden)

Mironov Aleksey

2014-09-01

Full Text Available Roller bearings are widely used in equipment of different applications; therefore, the issues related to the assessment of bearing technical state and localization of bearing faults are quite important and relevant. The reason is that technical state of a bearing is a critical component, which determines efficiency of a mechanism or equipment. For bearings inspection and diagnostics, various methods of vibration-based diagnostics are used. The adaptive technology for vibration-based diagnostics developed in „D un D centrs” is an effective tool for evaluation of technical state of bearings in operation compared to the existing SKF method.

Decreasing inventory of a cement factory roller mill parts using reliability centered maintenance method

Science.gov (United States)

Witantyo; Rindiyah, Anita

2018-03-01

According to data from maintenance planning and control, it was obtained that highest inventory value is non-routine components. Maintenance components are components which procured based on maintenance activities. The problem happens because there is no synchronization between maintenance activities and the components required. Reliability Centered Maintenance method is used to overcome the problem by reevaluating maintenance activities required components. The case chosen is roller mill system because it has the highest unscheduled downtime record. Components required for each maintenance activities will be determined by its failure distribution, so the number of components needed could be predicted. Moreover, those components will be reclassified from routine component to be non-routine component, so the procurement could be carried out regularly. Based on the conducted analysis, failure happens in almost every maintenance task are classified to become scheduled on condition task, scheduled discard task, schedule restoration task and no schedule maintenance. From 87 used components for maintenance activities are evaluated and there 19 components that experience reclassification from non-routine components to routine components. Then the reliability and need of those components were calculated for one-year operation period. Based on this invention, it is suggested to change all of the components in overhaul activity to increase the reliability of roller mill system. Besides, the inventory system should follow maintenance schedule and the number of required components in maintenance activity so the value of procurement will be decreased and the reliability system will increase.

Performance Analysis of Functionally Graded Coatings in Contact with Cylindrical Rollers

Directory of Open Access Journals (Sweden)

Reza Jahedi

2015-01-01

Full Text Available This work presents finite element analysis (FEA and results for rolling contact of a cylindrical roller on an elastic substrate coated by functionally graded material (FGM. The rolling process and the graded coating material property and layers arrangement are modeled using finite element codes which lead to a new methodology. This novel methodology provides a trend in determining surface contact stresses, deformations, contact zones, and energy dissipation through the contact area. Effects of stiffness ratio, friction, and exponentially variation of material property on the contact stresses and deformations are studied. Some of the results are verified with analytical solutions. The study results may be beneficial in graded coated cylindrical components analysis against rolling contact failure and wear.

Failure of the chassis of roller skates for agonistic figure skating

Directory of Open Access Journals (Sweden)

Giorgio Olmi

2015-04-01

Full Text Available The subject of this work was to investigate the early failure, which occurred in the chassis of a roller skate for figure skating. The paper deals with the preliminary analysis of the crack and with the integrated approach, which had to be followed to overcome the problem. Literature in the fields of physiology and biomechanics was studied to correctly simulate the load distribution on the chassis. Finite element simulation, experimental stress analysis and analytical modeling of impact phenomena had to be combined together to estimate the entity of dynamic loads and the corresponding state of stress. The analysis led to the determination of the primary cause of failure, bending fatigue, and to the suggestion of a simple solution to improve and optimize the project.

Field Assessment and Specification Review for Roller-Integrated Compaction Monitoring Technologies

Directory of Open Access Journals (Sweden)

David J. White

2011-01-01

Full Text Available Roller-integrated compaction monitoring (RICM technologies provide virtually 100-percent coverage of compacted areas with real-time display of the compaction measurement values. Although a few countries have developed quality control (QC and quality assurance (QA specifications, broader implementation of these technologies into earthwork construction operations still requires a thorough understanding of relationships between RICM values and traditional in situ point test measurements. The purpose of this paper is to provide: (a an overview of two technologies, namely, compaction meter value (CMV and machine drive power (MDP; (b a comprehensive review of field assessment studies, (c an overview of factors influencing statistical correlations, (d modeling for visualization and characterization of spatial nonuniformity; and (e a brief review of the current specifications.

Second-Order Free-Riding on Antisocial Punishment Restores the Effectiveness of Prosocial Punishment

Science.gov (United States)

Szolnoki, Attila; Perc, Matjaž

2017-10-01

Economic experiments have shown that punishment can increase public goods game contributions over time. However, the effectiveness of punishment is challenged by second-order free-riding and antisocial punishment. The latter implies that noncooperators punish cooperators, while the former implies unwillingness to shoulder the cost of punishment. Here, we extend the theory of cooperation in the spatial public goods game by considering four competing strategies, which are traditional cooperators and defectors, as well as cooperators who punish defectors and defectors who punish cooperators. We show that if the synergistic effects are high enough to sustain cooperation based on network reciprocity alone, antisocial punishment does not deter public cooperation. Conversely, if synergistic effects are low and punishment is actively needed to sustain cooperation, antisocial punishment does is viable, but only if the cost-to-fine ratio is low. If the costs are relatively high, cooperation again dominates as a result of spatial pattern formation. Counterintuitively, defectors who do not punish cooperators, and are thus effectively second-order free-riding on antisocial punishment, form an active layer around punishing cooperators, which protects them against defectors that punish cooperators. A stable three-strategy phase that is sustained by the spontaneous emergence of cyclic dominance is also possible via the same route. The microscopic mechanism behind the reported evolutionary outcomes can be explained by the comparison of invasion rates that determine the stability of subsystem solutions. Our results reveal an unlikely evolutionary escape from adverse effects of antisocial punishment, and they provide a rationale for why second-order free-riding is not always an impediment to the evolutionary stability of punishment.

Second-Order Free-Riding on Antisocial Punishment Restores the Effectiveness of Prosocial Punishment

Directory of Open Access Journals (Sweden)

Attila Szolnoki

2017-10-01

Full Text Available Economic experiments have shown that punishment can increase public goods game contributions over time. However, the effectiveness of punishment is challenged by second-order free-riding and antisocial punishment. The latter implies that noncooperators punish cooperators, while the former implies unwillingness to shoulder the cost of punishment. Here, we extend the theory of cooperation in the spatial public goods game by considering four competing strategies, which are traditional cooperators and defectors, as well as cooperators who punish defectors and defectors who punish cooperators. We show that if the synergistic effects are high enough to sustain cooperation based on network reciprocity alone, antisocial punishment does not deter public cooperation. Conversely, if synergistic effects are low and punishment is actively needed to sustain cooperation, antisocial punishment does is viable, but only if the cost-to-fine ratio is low. If the costs are relatively high, cooperation again dominates as a result of spatial pattern formation. Counterintuitively, defectors who do not punish cooperators, and are thus effectively second-order free-riding on antisocial punishment, form an active layer around punishing cooperators, which protects them against defectors that punish cooperators. A stable three-strategy phase that is sustained by the spontaneous emergence of cyclic dominance is also possible via the same route. The microscopic mechanism behind the reported evolutionary outcomes can be explained by the comparison of invasion rates that determine the stability of subsystem solutions. Our results reveal an unlikely evolutionary escape from adverse effects of antisocial punishment, and they provide a rationale for why second-order free-riding is not always an impediment to the evolutionary stability of punishment.

Micromechanical study of the effect of inclusions on fatigue failure in a roller bearing

DEFF Research Database (Denmark)

Cerullo, Michele; Tvergaard, Viggo

2015-01-01

model containing a single inclusion, using the approximation of a 2D plane strain numerical analysis. The Dang Van multiaxial fatigue criterion is used for the local stresses in the matrix material, to ensure that the stresses remain within the fatigue limit. The matrix material is taken to be one...... of the most commonly used bearing steels, AISI 52100, and two different types of inclusions are considered. The macroscopic stress histories applied correspond to either a Hertzian or an elastohydrodynamic (EHL) contact pressure distribution under the rollers. Findings - The paper shows that sub...

Therapist-Designed Adaptive Riding in Children With Cerebral Palsy : Results of a Feasibility Study

NARCIS (Netherlands)

Angsupaisal, Mattana; Visser, Baudina; Alkema, Anne; Meinsma-van der Tuin, Marja; Maathuis, Carel G. B.; Reinders-Messelink, Heleen; Hadders-Algra, Mijna

Background. It is debatable whether adaptive riding (AR) in children with cerebral palsy (CP) improves postural control and gross motor development. Objective. The study aim was to explore the feasibility of an extensive assessment protocol for a randomized controlled trial of therapist-designed

Hydrodynamic sliding bearings vs. roller bearings. Segmented sliding bearings for higher rotational speed; Hydrodynamische Gleitlager versus Waelzlager. Segmentgleitlager fuer hoehere Drehzahlen

Energy Technology Data Exchange (ETDEWEB)

Hagenhoff, M.; Sauer, M. [Main-Metall-Giesserei Fritz Schorr GmbH und Co. KG, Altenglan (Germany)

2004-10-01

Hydrodynamic sliding bearings are considered only in cases when roller bearings reach their speed limits and there is no other solution. However, this view neglects the fact that there are modern, optimised sliding bearings which have more advantages over roller bearings than should be expected. Many producers of sliding bearings also have computer programs enabling them to offer customised solutions, i.e. optimal adaptation of the bearings to their specific operating conditions. (orig.) [German] Hydrodynamische Gleitlager werden oft erst dann in Betracht gezogen, wenn man an die Drehzahlgrenzen von Waelzlagern stoesst und keine andere sinnvolle Alternative mehr in Frage kommt. Dabei uebersieht man leicht, dass es moderne, optimierte Gleitlagerkonstruktionen gibt, die weitaus haeufiger ihre Staerken im Vergleich zu Waelzlagern ausspielen koennen als zunaechst vermutet. Viele Gleitlagerhersteller haben zudem heute Berechnungsprogramme zur Verfuegung, die eine optimale Anpassung der Lager an die speziellen Betriebsbedingungen erlauben. (orig.)

The Ride of the Kings in Vlčnov from the Perspective of Contemporary Research

Czech Academy of Sciences Publication Activity Database

Stavělová, Daniela

2015-01-01

Roč. 25, č. 5 (2015), s. 47-64 ISSN 0862-8351 Institutional support: RVO:68378076 Keywords : Ride of the Kings * field research * methodology * festival * traditional custom * Vlčnov Subject RIV: AC - Archeology, Anthropology, Ethnology

RIDES: Robust Intrusion Detection System for IP-Based Ubiquitous Sensor Networks

Directory of Open Access Journals (Sweden)

Sungwon Lee

2009-05-01

Full Text Available TheIP-based Ubiquitous Sensor Network (IP-USN is an effort to build the “Internet of things”. By utilizing IP for low power networks, we can benefit from existing well established tools and technologies of IP networks. Along with many other unresolved issues, securing IP-USN is of great concern for researchers so that future market satisfaction and demands can be met. Without proper security measures, both reactive and proactive, it is hard to envisage an IP-USN realm. In this paper we present a design of an IDS (Intrusion Detection System called RIDES (Robust Intrusion DEtection System for IP-USN. RIDES is a hybrid intrusion detection system, which incorporates both Signature and Anomaly based intrusion detection components. For signature based intrusion detection this paper only discusses the implementation of distributed pattern matching algorithm with the help of signature-code, a dynamically created attack-signature identifier. Other aspects, such as creation of rules are not discussed. On the other hand, for anomaly based detection we propose a scoring classifier based on the SPC (Statistical Process Control technique called CUSUM charts. We also investigate the settings and their effects on the performance of related parameters for both of the components.

Edge coating apparatus with movable roller applicator for solar cell substrates

Science.gov (United States)

Pavani, Luca; Abas, Emmanuel

2012-12-04

A non-contact edge coating apparatus includes an applicator for applying a coating material on an edge of a solar cell substrate and a control system configured to drive the applicator. The control system may drive the applicator along an axis to maintain a distance with an edge of the substrate as the substrate is rotated to have the edge coated with a coating material. The applicator may include a recessed portion into which the edge of the substrate is received for edge coating. For example, the applicator may be a roller with a groove. Coating material may be introduced into the groove for application onto the edge of the substrate. A variety of coating materials may be employed with the apparatus including hot melt ink and UV curable plating resist.

Multivariable H force/level control of the twin-roller strip caster

International Nuclear Information System (INIS)

Cavazos, A.; Edwards, J.B.

2005-01-01

Twin-roller steel strip casters may offer some advantages with respect to classical continuous casting hot rolling processes. Some works have reported control aspects of this process and although the process has been found to be highly interactive and non-linear, little or no attention has been given to its multivariable characteristics. The purpose of this work is to design a multivariable control capable of decoupling the system. This paper presents some important aspects of the strip caster modeling and reports the simulation results of the application of the multivariable H-optimal control for nominal performance to force/level control. Various controllers have been designed for different pool level heights and it is shown that they can decouple the system, allowing the application of PI decentralized controllers to considerably improve performance. (author)

Low-voltage ride-through of a droop-based three-phase four-wire grid-connected microgrid

DEFF Research Database (Denmark)

Sadeghkhani, Iman; Golshan, Mohamad Esmail Hamedani; Mehrizi-Sani, Ali

2018-01-01

system operations during abnormal grid conditions. The objective of this paper is to propose an LVRT scheme that improves the power quality of the entire microgrid. The developed method is implemented as the controller of the interface voltage-sourced converter (VSC) of a distributed energy resource...... control of each phase and does not require calculation of symmetrical components. Moreover, it can be employed in the VSC control systems with various reference frames and is effective for droop-based grid-connected microgrids with both single-phase and three-phase four-wire configurations. The proposed......The ability of riding through the grid disturbances can increase the integration of microgrids into the distribution system. Consequently, a grid-connected microgrid should provide ancillary services such as low voltage ride-through (LVRT) capability and reactive power support to sustain the power...

Post-Closure Inspection Report for the Tonopah Test Range, Nevada

International Nuclear Information System (INIS)

NSTec Environmental Restoration

2007-01-01

This report provides the results of the semiannual post-closure inspections conducted at the closed Corrective Action Unit (CAU) sites located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2006 and includes inspection and repair activities completed at the following nine CAUs: CAU 400: Bomblet Pit and Five Points Landfill (TTR); CAU 404: Roller Coaster Lagoons and Trench (TTR); CAU 407: Roller Coaster RadSafe Area (TTR); CAU 423: Area 3 Underground Discharge Point, Building 0360 (TTR); CAU 424: Area 3 Landfill Complexes (TTR); CAU 426: Cactus Spring Waste Trenches (TTR); CAU 427: Area 3 Septic Waste Systems 2, 6 (TTR); CAU 453: Area 9 UXO Landfill (TTR); and CAU 487: Thunderwell Site (TTR). Post-closure inspections were conducted on May 9, 2006, May 31, 2006, and November 15, 2006. All inspections were conducted according to the post-closure plans in the approved Closure Reports. The post-closure inspection plan for each CAU is included in Attachment B, with the exception of CAU 400. CAU 400 does not require post-closure inspections, but inspections of the vegetation and fencing are conducted as a best management practice. The inspection checklists for each site inspection are included in Attachment C, the field notes are included in Attachment D, and the site photographs are included in Attachment E. Vegetation monitoring of CAU 400, CAU 404, CAU 407, and CAU 426 was performed in June 2006, and the vegetation monitoring report is included in Attachment F. Maintenance and/or repairs were performed at CAU 400, CAU 407, CAU 426, CAU 453, and CAU 487 in 2006. During the May inspection of CAU 400, it was identified that the east and west sections of chickenwire fencing beyond the standard fencing were damaged; they were repaired in June 2006. Also in June 2006, the southeast corner fence post and one warning sign at CAU 407 were reinforced and reattached, the perimeter fencing adjacent to the gate at CAU 426 was tightened, and large animal

Post-Closure Inspection Report for the Tonopah Test Range, Nevada

Energy Technology Data Exchange (ETDEWEB)

NSTec Environmental Restoration

2007-06-01

This report provides the results of the semiannual post-closure inspections conducted at the closed Corrective Action Unit (CAU) sites located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2006 and includes inspection and repair activities completed at the following nine CAUs: CAU 400: Bomblet Pit and Five Points Landfill (TTR); CAU 404: Roller Coaster Lagoons and Trench (TTR); CAU 407: Roller Coaster RadSafe Area (TTR); CAU 423: Area 3 Underground Discharge Point, Building 0360 (TTR); CAU 424: Area 3 Landfill Complexes (TTR); CAU 426: Cactus Spring Waste Trenches (TTR); CAU 427: Area 3 Septic Waste Systems 2, 6 (TTR); CAU 453: Area 9 UXO Landfill (TTR); and CAU 487: Thunderwell Site (TTR). Post-closure inspections were conducted on May 9, 2006, May 31, 2006, and November 15, 2006. All inspections were conducted according to the post-closure plans in the approved Closure Reports. The post-closure inspection plan for each CAU is included in Attachment B, with the exception of CAU 400. CAU 400 does not require post-closure inspections, but inspections of the vegetation and fencing are conducted as a best management practice. The inspection checklists for each site inspection are included in Attachment C, the field notes are included in Attachment D, and the site photographs are included in Attachment E. Vegetation monitoring of CAU 400, CAU 404, CAU 407, and CAU 426 was performed in June 2006, and the vegetation monitoring report is included in Attachment F. Maintenance and/or repairs were performed at CAU 400, CAU 407, CAU 426, CAU 453, and CAU 487 in 2006. During the May inspection of CAU 400, it was identified that the east and west sections of chickenwire fencing beyond the standard fencing were damaged; they were repaired in June 2006. Also in June 2006, the southeast corner fence post and one warning sign at CAU 407 were reinforced and reattached, the perimeter fencing adjacent to the gate at CAU 426 was tightened, and large animal

Comparing the impacts of hiking, skiing and horse riding on trail and vegetation in different types of forest.

Science.gov (United States)

Törn, A; Tolvanen, A; Norokorpi, Y; Tervo, R; Siikamäki, P

2009-03-01

Nature-based tourism in protected areas has increased and diversified dramatically during the last decades. Different recreational activities have a range of impacts on natural environments. This paper reports results from a comparison of the impacts of hiking, cross-country skiing and horse riding on trail characteristics and vegetation in northern Finland. Widths and depths of existing trails, and vegetation on trails and in the neighbouring forests were monitored in two research sites during 2001 and 2002. Trail characteristics and vegetation were clearly related to the recreational activity, research site and forest type. Horse trails were as deep as hiking trails, even though the annual number of users was 150-fold higher on the hiking trails. Simultaneously, cross-country skiing had the least effect on trails due to the protective snow cover during winter. Hiking trail plots had little or no vegetation cover, horse riding trail plots had lower vegetation cover than forest plots, while skiing had no impact on total vegetation cover. On the other hand, on horse riding trails there were more forbs and grasses, many of which did not grow naturally in the forest. These species that were limited to riding trails may change the structure of adjacent plant communities in the long run. Therefore, the type of activities undertaken and the sensitivity of habitats to these activities should be a major consideration in the planning and management of nature-based tourism. Establishment of artificial structures, such as stairs, duckboards and trail cover, or complete closure of the site, may be the only way to protect the most sensitive or deteriorated sites.

A behavioral choice model of the use of car-sharing and ride-sourcing services

Energy Technology Data Exchange (ETDEWEB)

Dias, Felipe F.; Lavieri, Patrícia S.; Garikapati, Venu M.; Astroza, Sebastian; Pendyala, Ram M.; Bhat, Chandra R.

2017-07-26

There are a number of disruptive mobility services that are increasingly finding their way into the marketplace. Two key examples of such services are car-sharing services and ride-sourcing services. In an effort to better understand the influence of various exogenous socio-economic and demographic variables on the frequency of use of ride-sourcing and car-sharing services, this paper presents a bivariate ordered probit model estimated on a survey data set derived from the 2014-2015 Puget Sound Regional Travel Study. Model estimation results show that users of these services tend to be young, well-educated, higher-income, working individuals residing in higher-density areas. There are significant interaction effects reflecting the influence of children and the built environment on disruptive mobility service usage. The model developed in this paper provides key insights into factors affecting market penetration of these services, and can be integrated in larger travel forecasting model systems to better predict the adoption and use of mobility-on-demand services.

Coordinated Low Voltage Ride through strategies for Permanent Magnet Direct Drive Synchronous Generators

Directory of Open Access Journals (Sweden)

Zhang Ge

2016-01-01

Full Text Available By analyzing the mechanism of the low voltage ride through on the permanent magnet direct drive synchronous wind power generating units, this paper proposes a coordinated control strategy for permanent magnet synchronous generator. In order to avoid over speed operation of the generation units, over voltage on DC capacitor and over current on convert, the improved pitch angle control and inverter control are used. When the grid voltage drops, the captured wind power is cut down by the variable pitch system, which limits the speed of the generator, the generator side converter keeps the DC capacitor voltage stabile; and the grid side converter provides reactive power to the grid to help the grid voltage recover. The control strategy does not require any additional hardware equipment, with existing control means, the unit will be able to realize low voltage ride through. Finally, based on Matlab/Simulink to build permanent magnet direct drive wind power generation system, the simulation results verify the correctness and effectiveness of the control strategy.

A First Step toward the Understanding of Implicit Learning of Hazard Anticipation in Inexperienced Road Users Through a Moped-Riding Simulator

Directory of Open Access Journals (Sweden)

Mariaelena Tagliabue

2017-05-01

Full Text Available Hazard perception is considered one of the most important abilities in road safety. Several efforts have been devoted to investigating how it improves with experience and can be trained. Recently, research has focused on the implicit aspects of hazard detection, reaction, and anticipation. In the present study, we attempted to understand how the ability to anticipate hazards develops during training with a moped-riding simulator: the Honda Riding Trainer (HRT. Several studies have already validated the HRT as a tool to enhance adolescents’ hazard perception and riding abilities. In the present study, as an index of hazard anticipation, we used skin conductance response (SCR, which has been demonstrated to be linked to affective/implicit appraisal of risk. We administered to a group of inexperienced road users five road courses two times a week apart. In each course, participants had to deal with eight hazard scenes (except one course that included only seven hazard scenes. Participants had to ride along the HRT courses, facing the potentially hazardous situations, following traffic rules, and trying to avoid accidents. During the task, we measured SCR and monitored driving performance. The main results show that learning to ride the simulator leads to both a reduction in the number of accidents and anticipation of the somatic response related to hazard detection, as proven by the reduction of SCR onset recorded in the second session. The finding that the SCR signaling the impending hazard appears earlier when the already encountered hazard situations are faced anew suggests that training with the simulator acts on the somatic activation associated with the experience of risky situations, improving its effectiveness in detecting hazards in advance so as to avoid accidents. This represents the starting point for future investigations into the process of generalization of learning acquired in new virtual situations and in real-road situations.

Rüütel pensionäride elujärje garandina / Janno Reiljan

Index Scriptorium Estoniae

Reiljan, Janno, 1951-2018

2006-01-01

Ilmunud ka: Severnoje Poberezhje (2006) 17. aug., lk. 2, Meie Maa (2006) 18. aug., lk. 2, Nädaline (2006) 22. aug., lk. 2, Vooremaa (2006) 22. aug., lk. 2, Valgamaalane (2006) 24. aug., lk. 2. Autor selgitab Eesti pensionäride elujärje kujunemise näitel, miks Rahvaliit ja Keskerakond nimetasid oma koostöölepingu garandiks president Arnold Rüütli

Modified Ride-On Cars and Young Children with Disabilities: Effects of Combining Mobility and Social Training

Directory of Open Access Journals (Sweden)

Hsiang-Han Huang

2018-01-01

Full Text Available BackgroundResearch has shown that the use of power mobility devices is safe and beneficial for motor and cognitive development in children with motor disabilities; nevertheless, strong evidence of the benefits for social skill development is limited. This study aimed to examine the effects of combining ride-on car training with an adult-directed, social interaction program in a hospital-based environment on mobility and social functions in young children with motor disabilities.MethodsThis study used a prospective, nonequivalent pretest–posttest control group design. Twenty-nine young children with motor disabilities, aged between 1 and 3 years, were recruited from local hospitals in Taiwan. The treatment group (n = 15 underwent 2-h ride-on car training sessions twice per week for a total of 9 weeks in the hospital environment. The control group (n = 14 underwent a 9-week home education program (mean: 200 min/week focusing on mobility and social skills training. The Chinese version of the Pediatric Evaluation of Disability Inventory, Parenting Stress Index, and Goal Attainment Scaling were administered to all participants before and after the intervention, and at the end of the 9-week follow-up phase.ResultsMobility and social functions significantly improved in both groups after the 9-week intervention, but this improvement was not maintained at the follow-up phase. The treatment group showed significantly better improvement in social function, parenting stress levels, and goal achievement than the control group at posttest.ConclusionThis two-group design study showed the benefits of combining a ride-on car use with a family-centered, structured, social interaction program for positive impacts on mobility, social function, and parenting stress levels. The combination of a modified ride-on car and a social training program has the potential to enhance socialization in young children with motor disabilities.Clinical Trial

Effect of the variation in the ambient moisture on the compaction behavior of powder undergoing roller-compaction and on the characteristics of tablets produced from the post-milled granules.

Science.gov (United States)

Gupta, Abhay; Peck, Garnet E; Miller, Ronald W; Morris, Kenneth R

2005-10-01

Effect of variation in the ambient moisture levels on the compaction behavior of a 10% acetaminophen (APAP) powder blend in microcrystalline cellulose (MCC) powder was studied by comparing the physical and mechanical properties of ribbons prepared by roller compaction with those of simulated ribbons, i.e., tablets prepared under uni-axial compression. Relative density, moisture content, tensile strength, and Young's modulus were used as key compact properties for comparison. Moisture was found to facilitate the particle rearrangement of both, the APAP and the MCC particles, as well as the deformation of the MCC particles. The tensile strength of the simulated ribbons also showed an increase with increasing moisture content. An interesting observation was that the tensile strength of the roller compacted samples first increased and then decreased with increasing moisture content. Variation in the ambient moisture during roller compaction was also found to influence the characteristics of tablets produced from the granules obtained post-milling the ribbons. A method to study this influence is also reported. Copyright (c) 2005 Wiley-Liss, Inc. and the American Pharmacists Association

Sandvik's HM 150 roller in action on the world's largest conveyor bridge in the Lusatia region; Sandvik HM 150 auf der weltgroessten Foerderbruecke in der Lausitz im Einsatz

Energy Technology Data Exchange (ETDEWEB)

Waliczek, Sven; Raddatz, Ulrich [Sandvik Mining and Construction Central Europe GmbH, Essen (Germany)

2010-09-15

Prince Herrmann Ludwig Heinrich von Pueckler-Muskau, a landscape gardening genius, built the Muskau Park in the Lusatia region in 1817 - it is part of a UNESCO world heritage site today. In the same era, 1850, the first lignite was mined in the region and still today, Vattenfall, the Swedish company, extracts lignite without subsidies - in Jaenschwalde among other places, one out of the five opencast mines currently in operation. As one of the largest employers and apprenticing companies in East Germany, Vattenfall currently employs almost 8000 employees and about 800 apprentices. Sandvik Mining and Construction also plays a leading role - in the literal sense. At the Jaenschwalde location there are 320 sets of 5-roller garlands of HM150 formed rollers in action on the overburden conveyor bridge AFB 60m (Figure 1) - on belt five, the main belt conveyor (belt type 3000 ST3000-18:8, idler spacing approx. 800 mm) and on belt eight, the stockpile belt conveyor (belt type 2750 ST2500-18:8, idler spacing approx. 800 mm). It all began in the spring of 2004. Bernhard Hofmayer, Production Manager at Sandvik, introduced the HM150 formed roller to Vattenfall. The engineers were impressed by the completely new design and the innovative assembly technique. The discussion about the advantages and disadvantages of the component optimised formed roller were ready to begin. (orig.)

Kinematic and dynamic modeling and approximate analysis of a roller chain drive

DEFF Research Database (Denmark)

Fuglede, Niels; Thomsen, Jon Juel

2016-01-01

for analytical studies of the coupled motion of the chain spans and driven sprocket. Parametric excitation of the spans come from sprocket angular displacements, and the driven sprocket acts as a boundary which can be compliant in the axial direction. External transverse excitation of the spans comes from...... polygonal action, and is treated through kinematic forcing at the moving string boundaries. Perturbation analysis of the model is carried out using the method of multiple scales. Results show a multitude of internal and external resonance conditions, and some examples are presented of both decoupled...... and coupled motion. Together, the kinematic and dynamic model are aimed toward providing a framework for conducting and understanding both numerical, and experimental investigations of roller chain drive dynamics....

Stability of a Light Sail Riding on a Laser Beam

Energy Technology Data Exchange (ETDEWEB)

Manchester, Zachary [John A. Paulson School of Engineering and Applied Science, Harvard University, 60 Oxford St., Cambridge, MA 02138 (United States); Loeb, Abraham, E-mail: zmanchester@seas.harvard.edu [Astronomy Department, Harvard University, 60 Garden St., Cambridge, MA 02138 (United States)

2017-03-10

The stability of a light sail riding on a laser beam is analyzed both analytically and numerically. Conical sails on Gaussian beams, which have been studied in the past, are shown to be unstable without active control or additional mechanical modifications. A new architecture for a passively stable sail-and-beam configuration is proposed. The novel spherical shell design for the sail is capable of “beam riding” without the need for active feedback control. Full three-dimensional ray-tracing simulations are performed to verify our analytical results.

Stability of a Light Sail Riding on a Laser Beam

International Nuclear Information System (INIS)

Manchester, Zachary; Loeb, Abraham

2017-01-01

The stability of a light sail riding on a laser beam is analyzed both analytically and numerically. Conical sails on Gaussian beams, which have been studied in the past, are shown to be unstable without active control or additional mechanical modifications. A new architecture for a passively stable sail-and-beam configuration is proposed. The novel spherical shell design for the sail is capable of “beam riding” without the need for active feedback control. Full three-dimensional ray-tracing simulations are performed to verify our analytical results.

A Low-Voltage Ride-Through Control Strategy for Three-Phase Grid-Connected PV Systems

DEFF Research Database (Denmark)

Afshari, Ehsan; Farhangi, Babak; Yang, Yongheng

2017-01-01

similar variations in the dc-link voltage of conventional two-stage PV inverters. In such systems with an electrolytic capacitor in the dc-link, the oscillations of the dc-link voltage with DGF can deteriorate the capacitor lifetime, and thus the entire system. The proposed Low-Voltage Ride-Through (LVRT...

Low voltage ride through strategies for SCIG wind turbines in distributed power generation systems

DEFF Research Database (Denmark)

Blaabjerg, Frede; Teodorescu, Remus; Rodriguez, Pedro

2008-01-01

Fulfilling the new grid codes constitutes one of the main challenges for the wind power industry, that is specially concerned about the new fault-ride-through requirements. Enhancing the operation of wind-turbines in front of grid faults is not only an important issue for new wind farms, but also...

Dropout Reasons in Iranian Youth Roller Skaters

Directory of Open Access Journals (Sweden)

Hosein H E Y D A R I

2014-12-01

Full Text Available The main drop - out reasons from the sport of roller skating amongst Iranian youth skaters has been examined. A questionnaire with 53 items (adopted from Enoksen, 2011 representing seven subscales namel y: training factors and facilities, executive factors and team, education and work obligations, motivational aspects, social - cultural environment, choice of other sport activities and interests and economic factors was especially developed for this researc h. Responses were measured on a Likert scale ranging from “strongly disagree” to “strongly agree” in relation to each statement. In all 11 2 skaters predominantly male (mean age 17.1, SD = 1.63 with a mean = 5.43 years of experience (SD = 2.92 that had di scontinued in the past two years completed the questionnaire. Results of one sample t - tests showed that all factors expect “social - cultural environment” are significant indicators for drop out from skating with “economical factors” scoring the highest rank ing. Correlational analysis showed that younger participants agree more strongly th at “executive factors and team” and “education and work obligations” were the best predictors of drop out. Those with fewer years of experience considered “training factors and facilities”, “motivational aspects and social and cultural environment” as more likely reasons for quitting. Implications of the findings are discussed.

Quantitative evaluation of hand cranking a roller pump in a crisis management drill.

Science.gov (United States)

Tomizawa, Yasuko; Tokumine, Asako; Ninomiya, Shinji; Momose, Naoki; Matayoshi, Toru

2008-01-01

The heart-lung machines for open-heart surgery have improved over the past 50 years; they rarely break down and are almost always equipped with backup batteries. The hand-cranking procedure only becomes necessary when a pump breaks down during perfusion or after the batteries have run out. In this study, the performance of hand cranking a roller pump was quantitatively assessed by an objective method using the ECCSIM-Lite educational simulator system. A roller pump connected to an extracorporeal circuit with an oxygenator and with gravity venous drainage was used. A flow sensor unit consisting of electromagnetic sensors was used to measure arterial and venous flow rates, and a built-in pressure sensor was used to measure the water level in the reservoir. A preliminary study of continuous cranking by a team of six people was conducted as a surprise drill. This system was then used at a perfusion seminar. At the seminar, 1-min hand-cranking drills were conducted by volunteers according to a prepared scenario. The data were calculated on site and trend graphs of individual performances were given to the participants as a handout. Preliminary studies showed that each person's performance was different. Results from 1-min drills showed that good performance was not related to the number of clinical cases experienced, years of practice, or experience in hand cranking. Hand cranking to maintain the target flow rate could be achieved without practice; however, manipulating the venous return clamp requires practice. While the necessity of performing hand cranking during perfusion due to pump failure is rare, we believe that it is beneficial for perfusionists and patients to include hand-cranking practice in periodic extracorporeal circulation crisis management drills because a drill allows perfusionists to mentally rehearse the procedures should such a crisis occur.

Acute Lameness in a Roller Pigeon ( Columba livia ) with Multicentric Lymphosarcoma.

Science.gov (United States)

Williams, Susan M; Williams, Robert J; Gogal, Robert M

2017-06-01

A 3-yr-old adult female roller pigeon ( Columba livia ) used as part of a breeding pair for an ongoing research study presented with acute left limb lameness. Palpation of the left leg and region revealed a large lump near the coxofemoral joint. The bird was able to ambulate in the cage, but would not brood her hatchling. The bird was humanely euthanized and necropsy was performed. Grossly, multiple large white to pale tan nodules were noted in the pancreas, lung, rib cage, intestines, and unilaterally in the left kidney. Microscopic examination of the various organs revealed neoplastic proliferation of round cells consistent with lymphoblasts. Immunohistochemistry was performed with the use of antibodies to CD3, CD79a, CD20, and CD21 to phenotype the cells. The results indicated that the neoplastic infiltrating cells were predominantly of T-cell origin.

The physiological and biomechanical contributions of poling to roller ski skating.

Science.gov (United States)

Sandbakk, Øyvind; Ettema, Gertjan; Holmberg, Hans-Christer

2013-08-01

Poling is considered to make a significant contribution to cross-country skiing with the skating technique. To better understand this contribution, the current investigation compared roller ski skating on a treadmill with the so-called G3 skating technique with (G3-P) and without poling (G3-NP). Seven male elite skiers performed 5-min submaximal tests at 8, 12, and 15 km h(-1), as well as an incremental test to exhaustion with both techniques on a 5 % incline. Ventilatory variables were assessed by open-circuit indirect calorimetry and three-dimensional kinematics analyzed using the Qualisys Pro Reflex system. G3-P was associated with approximately 15 % higher peak velocity and 10 % higher peak oxygen uptake than G3-NP in the incremental test (both P skating, specifically by enhancing peak oxygen uptake, skiing efficiency and associated biomechanical variables.

A Comprehensive Review of Low-Voltage-Ride-Through Methods for Fixed-Speed Wind Power Generators

DEFF Research Database (Denmark)

Moghadasi, Amirhasan; Sarwat, Arif; Guerrero, Josep M.

2016-01-01

This paper presents a comprehensive review of various techniques employed to enhance the low voltage ride through (LVRT) capability of the fixed-speed induction generators (FSIGs)-based wind turbines (WTs), which has a non-negligible 20% contribution of the existing wind energy in the world...

Speech Auditory Alerts Promote Memory for Alerted Events in a Video-Simulated Self-Driving Car Ride.

Science.gov (United States)

Nees, Michael A; Helbein, Benji; Porter, Anna

2016-05-01

Auditory displays could be essential to helping drivers maintain situation awareness in autonomous vehicles, but to date, few or no studies have examined the effectiveness of different types of auditory displays for this application scenario. Recent advances in the development of autonomous vehicles (i.e., self-driving cars) have suggested that widespread automation of driving may be tenable in the near future. Drivers may be required to monitor the status of automation programs and vehicle conditions as they engage in secondary leisure or work tasks (entertainment, communication, etc.) in autonomous vehicles. An experiment compared memory for alerted events-a component of Level 1 situation awareness-using speech alerts, auditory icons, and a visual control condition during a video-simulated self-driving car ride with a visual secondary task. The alerts gave information about the vehicle's operating status and the driving scenario. Speech alerts resulted in better memory for alerted events. Both auditory display types resulted in less perceived effort devoted toward the study tasks but also greater perceived annoyance with the alerts. Speech auditory displays promoted Level 1 situation awareness during a simulation of a ride in a self-driving vehicle under routine conditions, but annoyance remains a concern with auditory displays. Speech auditory displays showed promise as a means of increasing Level 1 situation awareness of routine scenarios during an autonomous vehicle ride with an unrelated secondary task. © 2016, Human Factors and Ergonomics Society.

Vibration analysis of paper machine's asymmetric tube roll supported by spherical roller bearings

Science.gov (United States)

Heikkinen, Janne E.; Ghalamchi, Behnam; Viitala, Raine; Sopanen, Jussi; Juhanko, Jari; Mikkola, Aki; Kuosmanen, Petri

2018-05-01

This paper presents a simulation method that is used to study subcritical vibrations of a tube roll in a paper machine. This study employs asymmetric 3D beam elements based on the Timoshenko beam theory. An asymmetric beam model accounts for varying stiffness and mass distributions. Additionally, a detailed rolling element bearing model defines the excitations arising from the set of spherical roller bearings at both ends of the rotor. The results obtained from the simulation model are compared against the results from the measurements. The results indicate that the waviness of the bearing rolling surfaces contributes significantly to the subcritical vibrations while the asymmetric properties of the tube roll have only a fractional effect on the studied vibrations.

Individual differences in behavioural inhibition explain free riding in public good games when punishment is expected but not implemented

Science.gov (United States)

2013-01-01

Background The literature on social dilemmas and punishment focuses on the behaviour of the punisher. However, to fully explain the effect of punishment on cooperation, it is important to understand the psychological mechanisms influencing the behaviour of those who expect to be punished. This paper examines whether the expectation of punishment, rather than the implementation of punishment is sufficient to prevent individuals from free riding. Individual differences in the punishment sensitivity have been linked to both threat responses (flight, fight, fear system, or the FFFS) and to the response to the uncertainty of punishment (BIS-anxiety).The paper, therefore, examines if individual differences in BIS-anxiety and FFFS can explain some of the variability in free riding in the face of implemented and non-implemented punishment. Methods Participants took part in a series of one-shot Public Goods Games (PGGs) facing two punishment conditions (implemented and non-implemented) and two standard non-punishment PGGs. The punishment was implemented as a centralized authority punishment (i.e., if one participant contributed less than their group members, they were automatically fined). Individual contribution levels and presence/absence of zero contributions indexed free riding. Individual differences in behavioural inhibition were assessed. Results Individuals contributed more under the threat of punishment (both implemented and non-implemented). However, individuals contributed less when the punishment was not implemented compared to when it was. Those scoring high in BIS-anxiety contributed more when the punishment expectations were not implemented. This effect was not observed for FFFS. Conclusion Supporting previous research, punishment had a powerful effect in increasing contribution levels in the PGGs. However, when expected punishment was not implemented, individual differences in punishment sensitivity, specifically in BIS-anxiety, were related to fewer

Individual differences in behavioural inhibition explain free riding in public good games when punishment is expected but not implemented

Directory of Open Access Journals (Sweden)

Skatova Anya

2013-01-01

Full Text Available Abstract Background The literature on social dilemmas and punishment focuses on the behaviour of the punisher. However, to fully explain the effect of punishment on cooperation, it is important to understand the psychological mechanisms influencing the behaviour of those who expect to be punished. This paper examines whether the expectation of punishment, rather than the implementation of punishment is sufficient to prevent individuals from free riding. Individual differences in the punishment sensitivity have been linked to both threat responses (flight, fight, fear system, or the FFFS and to the response to the uncertainty of punishment (BIS-anxiety.The paper, therefore, examines if individual differences in BIS-anxiety and FFFS can explain some of the variability in free riding in the face of implemented and non-implemented punishment. Methods Participants took part in a series of one-shot Public Goods Games (PGGs facing two punishment conditions (implemented and non-implemented and two standard non-punishment PGGs. The punishment was implemented as a centralized authority punishment (i.e., if one participant contributed less than their group members, they were automatically fined. Individual contribution levels and presence/absence of zero contributions indexed free riding. Individual differences in behavioural inhibition were assessed. Results Individuals contributed more under the threat of punishment (both implemented and non-implemented. However, individuals contributed less when the punishment was not implemented compared to when it was. Those scoring high in BIS-anxiety contributed more when the punishment expectations were not implemented. This effect was not observed for FFFS. Conclusion Supporting previous research, punishment had a powerful effect in increasing contribution levels in the PGGs. However, when expected punishment was not implemented, individual differences in punishment sensitivity, specifically in BIS-anxiety, were

Therapeutic Riding for a Student with Multiple Disabilities and Visual Impairment: A Case Study.

Science.gov (United States)

Lehrman, Jennifer; Ross, David B.

2001-01-01

A 9-year-old with multiple disabilities and visual impairments was the focus of a 10-week developmental therapeutic riding program incorporating hippotherapy. The program has led to increased mobility, an increase in visual attention span and fixation time, signs of greater verbal communication, and the acquisition of new functional signs.…

Challenges to Grid Synchronization of Single-Phase Grid-Connected Inverters in Zero-Voltage Ride-Through Operation

DEFF Research Database (Denmark)

Zhang, Zhen; Yang, Yongheng; Blaabjerg, Frede

2016-01-01

With the fast development in Photovoltaic (PV) technology, the relevant grid-connection requirements/standards are continuously being updated, and more challenges have been imposed on both single-phase and three-phase grid-connected PV systems. For instance, PV systems are currently required...... to remain connected under grid voltage sags (even zero voltage condition). In this case, much attention should be paid to the grid synchronization in such a way to properly ride-through grid faults. Thus, in this paper, the most commonly-used and recently-developed Phase Locked Loop (PLL) synchronization...... methods have been evaluated for single-phase grid-connected PV systems in the case of Zero-Voltage Ride-Through (ZVRT) operation. The performances of the prior-art PLL methods in response to zero voltage faults in terms of detection precision and dynamic response are assessed in this paper. Simulation...

Roller compaction: Effect of morphology and amorphous content of lactose powder on product quality.

Science.gov (United States)

Omar, Chalak S; Dhenge, Ranjit M; Osborne, James D; Althaus, Tim O; Palzer, Stefan; Hounslow, Michael J; Salman, Agba D

2015-12-30

The effect of morphology and amorphous content, of three types of lactose, on the properties of ribbon produced using roller compaction was investigated. The three types of lactose powders were; anhydrous SuperTab21AN, α-lactose monohydrate 200 M, and spray dried lactose SuperTab11SD. The morphology of the primary particles was identified using scanning electron microscopy (SEM) and the powder amorphous content was quantified using NIR technique. SEM images showed that 21AN and SD are agglomerated type of lactose whereas the 200 M is a non-agglomerated type. During ribbon production, an online thermal imaging technique was used to monitor the surface temperature of the ribbon. It was found that the morphology and the amorphous content of lactose powders have significant effects on the roller compaction behaviour and on ribbon properties. The agglomerated types of lactose produced ribbon with higher surface temperature and tensile strength, larger fragment size, lower porosity and lesser fines percentages than the non-agglomerated type of lactose. The lactose powder with the highest amorphous content showed to result in a better binding ability between the primary particles. This type of lactose produced ribbons with the highest temperature and tensile strength, and the lowest porosity and amount of fines in the product. It also produced ribbon with more smooth surfaces in comparison to the other two types of lactose. It was noticed that there is a relationship between the surface temperature of the ribbon during production and the tensile strength of the ribbon; the higher the temperature of the ribbon during production the higher the tensile strength of the ribbon. Copyright © 2015 Elsevier B.V. All rights reserved.

On the temperature dependence of H-Uiso in the riding hydrogen model

International Nuclear Information System (INIS)

Lübben, Jens; Volkmann, Christian; Grabowsky, Simon; Edwards, Alison; Morgenroth, Wolfgang; Fabbiani, Francesca P. A.; Sheldrick, George M.; Dittrich, Birger

2014-01-01

The temperature dependence of hydrogen U iso and parent U eq in the riding hydrogen model is investigated by neutron diffraction, aspherical-atom refinements and QM/MM and MO/MO cluster calculations. Fixed values of 1.2 or 1.5 appear to be underestimated, especially at temperatures below 100 K. The temperature dependence of H-U iso in N-acetyl-l-4-hydroxyproline monohydrate is investigated. Imposing a constant temperature-independent multiplier of 1.2 or 1.5 for the riding hydrogen model is found to be inaccurate, and severely underestimates H-U iso below 100 K. Neutron diffraction data at temperatures of 9, 150, 200 and 250 K provide benchmark results for this study. X-ray diffraction data to high resolution, collected at temperatures of 9, 30, 50, 75, 100, 150, 200 and 250 K (synchrotron and home source), reproduce neutron results only when evaluated by aspherical-atom refinement models, since these take into account bonding and lone-pair electron density; both invariom and Hirshfeld-atom refinement models enable a more precise determination of the magnitude of H-atom displacements than independent-atom model refinements. Experimental efforts are complemented by computing displacement parameters following the TLS+ONIOM approach. A satisfactory agreement between all approaches is found

Cybersickness provoked by head-mounted display affects cutaneous vascular tone, heart rate and reaction time.

Science.gov (United States)

Nalivaiko, Eugene; Davis, Simon L; Blackmore, Karen L; Vakulin, Andrew; Nesbitt, Keith V

2015-11-01

Evidence from studies of provocative motion indicates that motion sickness is tightly linked to the disturbances of thermoregulation. The major aim of the current study was to determine whether provocative visual stimuli (immersion into the virtual reality simulating rides on a rollercoaster) affect skin temperature that reflects thermoregulatory cutaneous responses, and to test whether such stimuli alter cognitive functions. In 26 healthy young volunteers wearing head-mounted display (Oculus Rift), simulated rides consistently provoked vection and nausea, with a significant difference between the two versions of simulation software (Parrot Coaster and Helix). Basal finger temperature had bimodal distribution, with low-temperature group (n=8) having values of 23-29 °C, and high-temperature group (n=18) having values of 32-36 °C. Effects of cybersickness on finger temperature depended on the basal level of this variable: in subjects from former group it raised by 3-4 °C, while in most subjects from the latter group it either did not change or transiently reduced by 1.5-2 °C. There was no correlation between the magnitude of changes in the finger temperature and nausea score at the end of simulated ride. Provocative visual stimulation caused prolongation of simple reaction time by 20-50 ms; this increase closely correlated with the subjective rating of nausea. Lastly, in subjects who experienced pronounced nausea, heart rate was elevated. We conclude that cybersickness is associated with changes in cutaneous thermoregulatory vascular tone; this further supports the idea of a tight link between motion sickness and thermoregulation. Cybersickness-induced prolongation of reaction time raises obvious concerns regarding the safety of this technology. Copyright © 2015 Elsevier Inc. All rights reserved.

How challenging is a riding horse’s life? Field studies on fitness, workload and welfare

NARCIS (Netherlands)

Munsters, C.C.B.M.

2013-01-01

The objectives of this thesis were to evaluate in practice workload, fitness and welfare of riding horses under work and training conditions. Chapter II presents an overview of the parameters used in earlier studies on training, behaviour and equine welfare, and describes the evaluation of the

A Low-Voltage Ride-Through Technique for Grid-Connected Converters with Reduced Power Transistors Stress

DEFF Research Database (Denmark)

Chen, Hsin-Chih; Lee, Chia-Tse; Cheng, Po-Tai

2016-01-01

With more and more distributed energy resources being installed in the utility grid, grid operators start imposing the low-voltage ride-through requirement on such systems to remain grid-connected and inject reactive and/or active current to support grid voltage during fault conditions. This pape...

The choice of Park & Ride Facilities: an analysis using a context-dependent hierarchical choice experiment

NARCIS (Netherlands)

Heijden, R.E.C.M. van der; Molin, E.J.E.; Timmermans, H.J.P.

2004-01-01

Park and Ride facilities have been proposed in several countries to alleviate the accessibility problems in cities. Despite growing accessibility problems, these facilities do not seem to attract the expected number of car drivers and are under-used. In an attempt to measure consumer evaluations of

The choice of park & ride facilities : an analysis using a context-dependent hierarchical choice experiment

NARCIS (Netherlands)

Bos, D.M.; vd Heijden, R.E.C.M.; Molin, E.J.E.; Timmermans, H.J.P.

2004-01-01

Park and Ride facilities have been proposed in several countries to alleviate the accessibility problems in cities. Despite growing accessibility problems, these facilities do not seem to attract the expected number of car drivers and are under-used. In an attempt to measure consumer evaluations of

Fast Coordinated Control of DFIG Wind Turbine Generators for Low and High Voltage Ride-Through

Directory of Open Access Journals (Sweden)

Yun Wang

2014-06-01

Full Text Available This paper presents a fast coordinated control scheme of the rotor side converter (RSC, the Direct Current (DC chopper and the grid side converter (GSC of doubly fed induction generator (DFIG wind turbine generators (WTGs to improve the low voltage ride through (LVRT and high voltage ride through (HVRT capability of the DFIG WTGs. The characteristics of DFIG WTGs under voltage sags and swells were studied focusing on the DFIG WTG stator flux and rotor voltages during the transient periods of grid voltage changes. The protection schemes of the rotor crowbar circuit and the DC chopper circuit were proposed considering the characteristics of the DFIG WTGs during voltage changes. The fast coordinated control of RSC and GSC were developed based on the characteristic analysis in order to realize efficient LVRT and HVRT of the DFIG WTGs. The proposed fast coordinated control schemes were verified by time domain simulations using Matlab-Simulink.

Cylinder deactivation for valve trains with roller finger follower; Zylinderabschaltung fuer Ventiltriebe mit Rollenschlepphebeln

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, Hermann; Loch, Adam; Widmann, Richard [Mahle International GmbH, Stuttgart (Germany). Zentrale Voraussentwicklung; Kreussen, Gerhard; Rebbert, Martin [FEV Motorentechnik GmbH, Aachen (Germany). Abt. Dynamik; Meehsen, Daniel [FEV Motorentechnik GmbH, Aachen (Germany). Abt. Mechanik Versuch

2009-04-15

Cylinder deactivation increases efficiency of gasoline engines without negative effects in terms of exhaust gas emissions or driving dynamics. In particular, the advantageous cost/benefit ratio and great affinity to technologies currently used in gasoline engines support cylinder deactivation as the right path in meeting future market demands. The design and function of cylinder deactivation for valve trains with roller finger follower will be explained and examined with regard to functional aspects, such as stiffness, mass, and kinematic behavior. Based on initial results, design and production characteristics of this new technology are evaluated and technical control interactions in engine applications are presented by Mahle. (orig.)

Abrasion Resistance of Nano Silica Modified Roller Compacted Rubbercrete: Cantabro Loss Method and Response Surface Methodology Approach

Science.gov (United States)

Adamu, Musa; Mohammed, Bashar S.; Shafiq, Nasir

2018-04-01

Roller compacted concrete (RCC) when used for pavement is subjected to skidding/rubbing by wheels of moving vehicles, this causes pavement surface to wear out and abrade. Therefore, abrasion resistance is one of the most important properties of concern for RCC pavement. In this study, response surface methodology was used to design, evaluate and analyze the effect of partial replacement of fine aggregate with crumb rubber, and addition of nano silica on the abrasion resistance of roller compacted rubbercrete (RCR). RCR is the terminology used for RCC pavement where crumb rubber was used as partial replacement to fine aggregate. The Box-Behnken design method was used to develop the mixtures combinations using 10%, 20%, and 30% crumb rubber with 0%, 1%, and 2% nano silica. The Cantabro loss method was used to measure the abrasion resistance. The results showed that the abrasion resistance of RCR decreases with increase in crumb rubber content, and increases with increase in addition of nano silica. The analysis of variance shows that the model developed using response surface methodology (RSM) has a very good degree of correlation, and can be used to predict the abrasion resistance of RCR with a percentage error of 5.44%. The combination of 10.76% crumb rubber and 1.59% nano silica yielded the best combinations of RCR in terms of abrasion resistance of RCR.

Management of lower extremity riding lawn mower injuries in children.

Science.gov (United States)

Kroening, L; Davids, J R

2000-01-01

Eight children are injured by riding lawn mowers every day. The child, usually a bystander or passenger on the mower, can sustain life-threatening and limb-threatening injuries. Multidisciplinary care must be available to manage the numerous issues presented by the unique circumstance of a child with a severe injury in the acute and chronic settings. Whether the limb is salvaged or amputated, the ultimate goal is optimal functional outcome for the patient. We have developed a team approach to address these injuries from their onset until patient maturity, maximizing our ability to achieve this goal.

Hot roller embossing system equipped with a temperature margin-based controller

Energy Technology Data Exchange (ETDEWEB)

Kim, Seyoung, E-mail: seyoungkim@kimm.re.kr; Son, Youngsu; Lee, Sunghee; Ham, Sangyong; Kim, Byungin [Department of Robotics and Mechatronics, Korea Institute of Machinery and Materials (KIMM), Daejeon (Korea, Republic of)

2014-08-15

A temperature control system was proposed for hot roller embossing. The roll surface was heated using induction coils and cooled with a circulating chilled water system. The temperature of the roll surface was precisely controlled by a temperature margin-based control algorithm that we developed. Implementation of the control system reduced deviations in the roll surface temperature to less than ±2 °C. The tight temperature control and the ability to rapidly increase and decrease the roll temperature will allow optimum operating parameters to be developed quickly. The temperature margin-based controller could also be used to optimize the time course of electrical power and shorten the cooling time by choosing an appropriate temperature margin, possibly for limited power consumption. The chiller-equipped heating roll with the proposed control algorithm is expected to decrease the time needed to determine the optimal embossing process.

New roller cone bits with unique nozzle designs reduce drilling costs

International Nuclear Information System (INIS)

Moffitt, S.R.; Pearce, D.E.; Ivie, C.R.

1992-01-01

This paper reports that selection of the optimum rock bit design to achieve the lowest drilling cost in a given application is often difficult due to a large number of rock bit performance considerations. However, in a majority of applications increased penetration rate is the key consideration in reducing drilling costs. Discovery of a new bit design concept has led to the development of roller cone bits that achieve significant penetration rate increases using superior hydraulic nozzle designs. Prototype designs have achieved 20 to 40% increases in penetration rate with comparable footage drilled when tested in 6 1/2, 8 1/2, 8-3/4, 9-7/8 and 12 1/4 IADC 437, 517 and 537 type bits in the U.S., North Sea, Italy, and Oman. Second-generation designs tested in a full-scale drilling laboratory have delivered 70% increases in penetration rates

Hot roller embossing system equipped with a temperature margin-based controller

International Nuclear Information System (INIS)

Kim, Seyoung; Son, Youngsu; Lee, Sunghee; Ham, Sangyong; Kim, Byungin

2014-01-01

A temperature control system was proposed for hot roller embossing. The roll surface was heated using induction coils and cooled with a circulating chilled water system. The temperature of the roll surface was precisely controlled by a temperature margin-based control algorithm that we developed. Implementation of the control system reduced deviations in the roll surface temperature to less than ±2 °C. The tight temperature control and the ability to rapidly increase and decrease the roll temperature will allow optimum operating parameters to be developed quickly. The temperature margin-based controller could also be used to optimize the time course of electrical power and shorten the cooling time by choosing an appropriate temperature margin, possibly for limited power consumption. The chiller-equipped heating roll with the proposed control algorithm is expected to decrease the time needed to determine the optimal embossing process

Experimental investigation of biodynamic human body models subjected to whole-body vibration during a vehicle ride.

Science.gov (United States)

Taskin, Yener; Hacioglu, Yuksel; Ortes, Faruk; Karabulut, Derya; Arslan, Yunus Ziya

2018-02-06

In this study, responses of biodynamic human body models to whole-body vibration during a vehicle ride were investigated. Accelerations were acquired from three different body parts, such as the head, upper torso and lower torso, of 10 seated passengers during a car ride while two different road conditions were considered. The same multipurpose vehicle was used during all experiments. Additionally, by two widely used biodynamic models in the literature, a set of simulations were run to obtain theoretical accelerations of the models and were compared with those obtained experimentally. To sustain a quantified comparison between experimental and theoretical approaches, the root mean square acceleration and acceleration spectral density were calculated. Time and frequency responses of the models demonstrated that neither of the models showed the best prediction performance of the human body behaviour in all cases, indicating that further models are required for better prediction of the human body responses.

76 FR 61279 - Defense Federal Acquisition Regulation Supplement; Defense Cargo Riding Gang Member (DFARS Case...

Science.gov (United States)

2011-10-04

... that the language of the proposed clause be amended to read as follows to reinforce DoD's role in the... Military Sealift Command), and specific procedural guidance for DoD personnel obtaining the background... 247.5. B. Language Inconsistency Comment: DFARS 252.247-7027(a) defines ``riding gang member'' as it...

Texas hospitals riding tall. While hospitals post robust profit margins, HMOs are saddled with mounting losses.

Science.gov (United States)

Saphir, A

1999-02-08

In Texas, they do things differently, and they do things big. Hospitals in the Lone Star State have been banding together more often and more effectively than elsewhere. Swinging their lassos, they are riding herd on HMOs, enjoying record profits and making ever-larger deals.

The choice of park and ride facilities : an analysis using a context-dependent hierarchical choice experiment

NARCIS (Netherlands)

Bos, D.M.; vd Heijden, R.E.C.M.; Molin, E.J.E.; Timmermans, H.J.P.

2004-01-01

Park and ride (P & R) facilities have been proposed in several countries to alleviate the accessibility problems in cities. Despite growing accessibility problems, these facilities do not seem to attract the expected number of car drivers and are underused. In an attempt to measure consumer

Why People Are Not Willing to Let Their Children Ride in Driverless School Buses: A Gender and Nationality Comparison

Directory of Open Access Journals (Sweden)

Emily C. Anania

2018-02-01

Full Text Available As driverless vehicles proliferate, it is possible that this technology will be applied in mass transport vehicles. School buses may be suited for autonomous operations as they follow set routes and schedules. However, a research gap exists in whether or not parents would be willing to have their children ride in autonomously operated school buses. The purpose of this study was to examine parents’ willingness to allow their child to ride in an autonomous school bus. Participant gender and nationality were also two independent variables, along with affect measures as a possible mediating variable. The research used a two-study approach. In study one, it was found that participants were less willing to have their child ride in a driverless school bus than a traditional human-operated vehicle. In study two, findings suggest a significant interaction between the type of driver, participant gender, and nationality. In general, American females were less willing than Indian females and overall, Americans were less willing than Indians in the driverless conditions. Affect was found to be a mediating variable, which suggests that emotions were playing a role in the responses of participants. The paper concludes with theoretical contributions, practical applications, and suggestions for future research.

Disentangling migratory routes and wintering grounds of Iberian near-threatened European Rollers Coracias garrulus.

Directory of Open Access Journals (Sweden)

Juan Rodríguez-Ruiz

Full Text Available Long-distance migrants are suffering drastic declines in the last decades. Causes beneath this problem are complex due to the wide spatial and temporal scale involved. We aim to reveal migratory routes, stopover areas, wintering grounds, and migratory strategies for the most southwestern populations of the near-threatened European Roller Coracias garrulus in order to identify conservation key areas for the non-breeding stage of this species. To this end, we used tracking data from seven satellite transmitters fitted to birds breeding in different populations throughout the Iberian Peninsula and four geolocators fitted to individuals in a southeastern Iberian population. Precise satellite data were used to describe daily activity patterns and speed in relation to the main regions crossed during the migration. Individuals from the most southwestern Iberian populations made a detour towards the Atlantic African coast whereas those from northeastern populations followed a straight north-to-south route. We identified important stopover areas in the Sahel belt, mainly in the surroundings of the Lake Chad, and wintering grounds on southwestern Africa farther west than previously reported for the species. Concerning the migratory strategy, satellite data revealed: 1 a mainly nocturnal flying activity, 2 that migration speed depended on the type of crossed habitat, with higher average speed while crossing the desert; and 3 that the migration was slower and lasted longer in autumn than in spring. The studied populations showed weak migratory connectivity, suggesting the confluence of birds from a wide range of breeding grounds in a restricted wintering area. Therefore, we suggest to target on defining precisely key areas for this species and identifying specific threats in them in order to develop an appropriate global conservation programme for the European Roller.

Impact of fault ride-through requirements on fixed-speed wind turbine structural loads

DEFF Research Database (Denmark)

Hansen, Anca Daniela; Cutululis, Nicolaos Antonio; Markou, Helen

2011-01-01

by performing a rainflow and a statistical analysis for fatigue and ultimate structural loads, respectively. Two cases are compared i.e. one where the turbine is immediately disconnected from the grid when a grid fault occurs and one where the turbine is equipped with a fault ride-through controller...... and therefore it is able to remain connected to the grid during the grid fault. Copyright © 2010 John Wiley & Sons, Ltd....

[Prevention of injuries associated with horseback riding].

Science.gov (United States)

ten Kate, Chantal A; de Kooter, Tabitha A; Kramer, William L M

2015-01-01

Each year 9,900 equestrians present at Accident and Emergency Departments, 40% of them 10-19 year old females. The most common horse-riding injuries are to the head, brain, neck and face, torso and extremities. Because of the relatively larger head, children more often fall on their head. Wearing a helmet gives considerable protection. Despite the common use of a helmet by horseback riders, serious head injury still occurs regularly. Further research into improvement of the protective function of the helmet is indicated. The current safety vest (body protector) does not significantly reduce the risk of torso injury. Improvement of its protective function is necessary. Injury to the lower extremities is caused when they become trapped in the stirrup in a fall from or with the horse. Safety stirrups and sturdy footwear are possible preventive measures. Investment in the quality and promotion of preventive measures could reduce the frequency and severity of equestrian injuries.

Active power control strategies for inverter-based distributed power generation adapted to grid-fault ride-through requirements

NARCIS (Netherlands)

Wang, F.; Duarte, J.L.; Hendrix, M.A.M.

2009-01-01

Distributed power generation is expected to deliver power into the grid without interruption during voltage dips. To improve system ride-through capabilities, a generalized active power control strategy is proposed for grid-interfacing inverters. Specifically, a current reference generation strategy

Integrating stochastic time-dependent travel speed in solution methods for the dynamic dial-a-ride problem.

Science.gov (United States)

Schilde, M; Doerner, K F; Hartl, R F

2014-10-01

In urban areas, logistic transportation operations often run into problems because travel speeds change, depending on the current traffic situation. If not accounted for, time-dependent and stochastic travel speeds frequently lead to missed time windows and thus poorer service. Especially in the case of passenger transportation, it often leads to excessive passenger ride times as well. Therefore, time-dependent and stochastic influences on travel speeds are relevant for finding feasible and reliable solutions. This study considers the effect of exploiting statistical information available about historical accidents, using stochastic solution approaches for the dynamic dial-a-ride problem (dynamic DARP). The authors propose two pairs of metaheuristic solution approaches, each consisting of a deterministic method (average time-dependent travel speeds for planning) and its corresponding stochastic version (exploiting stochastic information while planning). The results, using test instances with up to 762 requests based on a real-world road network, show that in certain conditions, exploiting stochastic information about travel speeds leads to significant improvements over deterministic approaches.

Compression fractures of the vertebrae during a "bumpy" boat ride.

LENUS (Irish Health Repository)

Chukwunyerenwa, C K

2012-01-31

INTRODUCTION: Compression fracture of the vertebrae is common, often the result of falls from height and motor vehicle accidents in the younger age groups. It can occur following minor trauma in the elderly and in those with osteoporosis. MATERIALS AND METHODS: We present an interesting case of compression fracture of the vertebral bodies occurring simultaneously in a couple during a boat ride while on holiday. One individual had fracture of the T8, while the other fractured the L1 vertebrae. Both injuries were treated conservatively with Taylor braces. CONCLUSION: We highlight one of the potential hazards of this recreational activity, and the almost identical fracture pattern in this couple.

The influence of API concentration on the roller compaction process: modeling and prediction of the post compacted ribbon, granule and tablet properties using multivariate data analysis.

Science.gov (United States)

Boersen, Nathan; Carvajal, M Teresa; Morris, Kenneth R; Peck, Garnet E; Pinal, Rodolfo

2015-01-01

While previous research has demonstrated roller compaction operating parameters strongly influence the properties of the final product, a greater emphasis might be placed on the raw material attributes of the formulation. There were two main objectives to this study. First, to assess the effects of different process variables on the properties of the obtained ribbons and downstream granules produced from the rolled compacted ribbons. Second, was to establish if models obtained with formulations of one active pharmaceutical ingredient (API) could predict the properties of similar formulations in terms of the excipients used, but with a different API. Tolmetin and acetaminophen, chosen for their different compaction properties, were roller compacted on Fitzpatrick roller compactor using the same formulation. Models created using tolmetin and tested using acetaminophen. The physical properties of the blends, ribbon, granule and tablet were characterized. Multivariate analysis using partial least squares was used to analyze all data. Multivariate models showed that the operating parameters and raw material attributes were essential in the prediction of ribbon porosity and post-milled particle size. The post compacted ribbon and granule attributes also significantly contributed to the prediction of the tablet tensile strength. Models derived using tolmetin could reasonably predict the ribbon porosity of a second API. After further processing, the post-milled ribbon and granules properties, rather than the physical attributes of the formulation were needed to predict downstream tablet properties. An understanding of the percolation threshold of the formulation significantly improved the predictive ability of the models.

Acute, fatal Sarcocystis calchasi-associated hepatitis in Roller pigeons (Columba livia f. dom.) at Philadelphia Zoo.

Science.gov (United States)

Trupkiewicz, J G; Calero-Bernal, R; Verma, S K; Mowery, J; Davison, S; Habecker, P; Georoff, T A; Ialeggio, D M; Dubey, J P

2016-01-30

Four Roller pigeons (Columba livia f. dom.) at the Philadelphia Zoo died suddenly. Necropsy examination revealed macroscopic hepatitis. Microscopically, the predominant lesions were in liver, characterized with necrosis and mixed cell inflammatory response. Sarcocystis calchasi-like schizonts and free merozoites were identified in liver. Transmission electron microscopy confirmed that schizonts were in hepatocytes. A few schizonts were in spleen. PCR using S. calchasi-specific primers confirmed the diagnosis. Neither lesions nor protozoa were found in brain and muscles. This is the first report of acute visceral S. calchasi-associated sarcocystosis in naturally infected avian hosts. Published by Elsevier B.V.

Rapid emergence of free-riding behavior in new pediatric immunization programs.

Directory of Open Access Journals (Sweden)

Chris T Bauch

Full Text Available BACKGROUND: Mathematical models have formalized how free-rider effects can threaten the stability of high vaccine coverage levels under established voluntary vaccination programs. However, little research has addressed the question of when free-riding begins to develop when a new vaccine is first introduced in a population. METHODOLOGY/PRINCIPAL FINDINGS: Here, we combine a game theoretical model of vaccinating behavior with an age-structured compartmental model to analyze rational vaccinating behavior in the first years of a universal immunization program, where a new vaccine is free to all children of a specified age. The model captures how successive birth cohorts face different epidemiological landscapes that have been shaped by the vaccinating decisions of previous birth cohorts, resulting in a strategic interaction between individuals in different birth cohorts. The model predicts a Nash equilibrium coverage level of for the first few birth cohorts under the new program. However, free-riding behavior emerges very quickly, with the Nash equilibrium vaccine coverage dropping significantly within 2-5 years after program initiation. Subsequently, a rich set of coupled dynamics between infection prevalence and vaccinating behaviors is possible, ranging from relatively stable (but reduced coverage in later birth cohorts to wide fluctuations in vaccine coverage from one birth cohort to the next. Individual tolerance for vaccine risk also starts out at relatively high levels before dropping significantly within a few years. CONCLUSIONS/SIGNIFICANCE: These results suggest that even relatively new immunization programs can be vulnerable to drops in vaccine coverage caused by vaccine scares and exacerbated by herd immunity effects, necessitating vigilance from the start.

A comparative study of physical and chemical properties of different pozzolanic materials used for roller compacted concrete RCC dams

OpenAIRE

Husein Malkawi Abdallah I.; Shatnawi Ehab; Husein Malkawi Dima A.

2017-01-01

This paper addresses the feasibility and the efficiency of using Natural Pozzolan and/or Rock flour in Roller Compacted Concrete (RCC) gravity dams. For this purpose, five identical mortar trial mixes were prepared using five different supplementary materials, i.e., fly ash produced in South Africa (proven to be effective in RCC construction), fly ash produced in Turkey, Jordanian natural pozzolan, Saudi natural pozzolan, and rock flour from Mujib Dam basalt quarry. The physical and chemical ...

Three-dimensional earthquake analysis of roller-compacted concrete dams

Directory of Open Access Journals (Sweden)

M. E. Kartal

2012-07-01

Full Text Available Ground motion effect on a roller-compacted concrete (RCC dams in the earthquake zone should be taken into account for the most critical conditions. This study presents three-dimensional earthquake response of a RCC dam considering geometrical non-linearity. Besides, material and connection non-linearity are also taken into consideration in the time-history analyses. Bilinear and multilinear kinematic hardening material models are utilized in the materially non-linear analyses for concrete and foundation rock respectively. The contraction joints inside the dam blocks and dam–foundation–reservoir interaction are modeled by the contact elements. The hydrostatic and hydrodynamic pressures of the reservoir water are modeled with the fluid finite elements based on the Lagrangian approach. The gravity and hydrostatic pressure effects are employed as initial condition before the strong ground motion. In the earthquake analyses, viscous dampers are defined in the finite element model to represent infinite boundary conditions. According to numerical solutions, horizontal displacements increase under hydrodynamic pressure. Besides, those also increase in the materially non-linear analyses of the dam. In addition, while the principle stress components by the hydrodynamic pressure effect the reservoir water, those decrease in the materially non-linear time-history analyses.

Come on and take a free ride : Contributing to public goods in native and foreign language settings

NARCIS (Netherlands)

Urbig, Diemo; Terjesen, Siri; Procher, Vivien; Muehlfeld, Katrin; Van Witteloostuijn, Arjen

2016-01-01

Business schools around the world must prepare their students for two realities: operating in an English-speaking business world and working in teams. As yet, there is limited understanding of how operating in a native or a foreign language impacts students' propensity to free ride in group

Come on and take a free ride : Contributing to public goods in native and foreign language settings

NARCIS (Netherlands)

Urbig, D.; Terjesen, S.; Procher, V.; Muhlfeld, K.S.; van Witteloostuijn, A.

Business schools around the world must prepare their students for two realities: operating in an English-speaking business world and working in teams. As yet, there is limited understanding of how operating in a native or a foreign language impacts students' propensity to free ride in group

How much can you drink before driving? The influence of riding with impaired adults and peers on the driving behaviors of urban and rural youth.

Science.gov (United States)

Leadbeater, Bonnie J; Foran, Kathleen; Grove-White, Aidan

2008-04-01

Following an ecological model to specify risks for impaired driving, we assessed the effects of youth attitudes about substance use and their experiences of riding in cars with adults and peers who drove after drinking alcohol or smoking cannabis on the youths' own driving after drinking or using cannabis. Participants were 2594 students in grades 10 and 12 (mean age = 16 years and 2 months; 50% girls) from public high schools in urban (994) and rural communities (1600) on Vancouver Island in British Columbia, Canada; 1192 of these were new drivers with restricted licenses. Self-report data were collected in anonymous questionnaires. Regression analyses were used to assess the independent and interacting effects of youth attitudes about substance use and their experiences of riding in cars with adults or peers who drove after drinking alcohol or smoking cannabis on youth driving. Youth driving risk behaviors were associated independently with their own high-risk attitudes and experiences riding with peers who drink alcohol or use cannabis and drive. However, risks were highest for the youth who also report more frequent experiences of riding with adults who drink alcohol or use cannabis and drive. Prevention efforts should be expanded to include the adults and peers who are role models for new drivers and to increase youths' awareness of their own responsibilities for their personal safety as passengers.

Ride-sharing business model for sustainability in developing country: Case Study Nebengers, Indonesia

Science.gov (United States)

Asirin, Asirin; Azhari, Danang

2018-05-01

The growth of population and urban economy increased the need for humans’ mobility to support their activities. On the other hand, online Information and Communication Technology (ICT) is growing rapidly and more affordable. Within few years, there is some sharing economy business formed by using online platform. This condition brings through the emergence of ride-sharing business model using an online platform which can be beneficial to sustainability. This research aims to explore one of ridesharing business models which use the online platform and its impact on sustainability. This research used the procedure of case study method with a single case study of Nebengers. This research explores the case study with the scope of this research is limited by using several conceptual frameworks, they are sharing economy business model, four elements of a business model for sustainability (BMfS), Social Construction of Technology (SCoT), sustainable mobility and agency theory. Nebengers is a sharing economy business using online platform that historically can be explained using Social Construction of Technology (SCoT) Theory. There are conflicts between nebengers entrepreneur and the city government. Nebengers disrupts traditional and formal public transportation services which are managed by the government. However, nebengers also contributes to achieve the city government goal in developing sustainable mobility. The future challenge is how to arrange ride-sharing collaborative governance business model for sustainability in the cities in Indonesia.

Long-term bicycle riding ameliorates the depression of the patients undergoing hemodialysis by affecting the levels of interleukin-6 and interleukin-18

Directory of Open Access Journals (Sweden)

Zhao C

2016-12-01

Full Text Available Chunhui Zhao, Hui Ma, Lei Yang, Yong Xiao Blood Purification Center, The First Affiliated Hospital of Dalian Medical University, Dalian, People’s Republic of China Purpose: Hemodialysis patients with depression have a higher risk of death and hospitalization. Although there is pharmacological management for the depression of hemodialysis patients, the adverse effect of the drug limits the use. The nonpharmacological way, bicycle riding, may be an effective way for the therapy of the depression in hemodialysis patients. However, the underlying mechanism of this relationship is still not fully explained, while interleukin-6 (IL-6 and interleukin-18 (IL-18 are associated with depression and exercise. Thus, the effects of bicycle riding on the levels of the interleukin were explored. Participants and methods: One hundred and eighty-nine patients with chronic hemodialysis were selected and randomly assigned to three groups of medicine (MG, received 20-mg escitalopram daily, medicine and aerobic exercise (MAG, received 20-mg escitalopram daily and bicycle riding six times weekly, and only aerobic exercise (AG, received 20-mg placebo daily and bicycle riding six times weekly. The whole experiment lasted for 18 weeks. The quality of life (36-Item Short Form Health Survey and depression severity according to criteria in the Diagnostic and Statistical Manual of Mental Disorders, fourth edition [DSM-IV] were measured before and at the end of this study. The serum levels of IL-6 and IL-18 were measured by an enzyme-linked immunosorbent assay kit. Results: The quality of life was improved and depression severity was reduced significantly in the MAG and AG groups when compared with the MG group (P<0.05. Serum levels of IL-6 and IL-18 were the highest in the MG group, moderate in the MAG group and the lowest in AG group. On the other hand, the serum levels of IL-6 and IL-18 were closely associated with depression scores (P<0.05. Conclusion: Aerobic exercise

The influence of incline and speed on work rate, gross efficiency and kinematics of roller ski skating.

Science.gov (United States)

Sandbakk, Øyvind; Ettema, Gertjan; Holmberg, Hans-Christer

2012-08-01

During competitions, elite cross-country skiers produce higher external work rates on uphill than on flat terrain. However, it is not presently known whether this reflects solely higher energy expenditure. Furthermore, the kinematic factors associated with these higher rates of uphill work have not yet been examined. Therefore, in the present investigation the work rate and associated kinematic parameters at similar metabolic rates during roller ski skating on flat and uphill terrains have been compared. Seven elite male skiers performed six 5-min sub-maximal exercise bouts at the same low, moderate and high metabolic rates on 2 and 8% inclines, while roller skiing on a treadmill employing the G3 skating technique. The work rate was calculated as work against gravity and friction, whereas the energetic equivalent of VO(2) was taken as the metabolic rate. Gross efficiency was defined as work rate divided by metabolic rate. Kinematic parameters were analyzed in three dimensions. At the same metabolic rate, the work rate, cycle rate, work per cycle and relative duration of propulsive phases during a cycle of movement were all higher on the 8% than on the 2% incline at all speeds (all P < 0.05). At similar work rates, gross efficiency was greater on the 8% incline (P < 0.05). In conclusion, these elite skiers consistently demonstrated higher work rates on the 8% incline. To achieve the higher work rates on the steeper incline, these elite skiers employed higher cycle rates and performed more work per cycle, in association with a longer relative propulsive phase.

Effects of the Horse Riding Simulator and Ball Exercises on Balance of the Elderly

Science.gov (United States)

Kim, SeongGil; Yuk, Goon-chang; Gak, Hwangbo

2013-01-01

[Purpose] The aim of this study was to examine the effects of horse riding exercise using a horse riding simulator (HRS) and a ball on static and dynamic balance of elderly people. [Methods] Thirty-two elderly people hospitalized in geriatric hospitals were randomly assigned to the HRS exercise group or the ball exercise groups, and they performed exercise for eight weeks. [Results] The length of postural sway during quite standing with and without eyes closed significantly decreased in both groups after the exercises and there was no significant difference between both groups in the Romberg test. In the functional reach test (FRT), there were significant increases in distance in both groups after the exercises, and the distance of the HRS exercise group was significantly greater than that of the ball exercise group. In the Timed Up & Go test (TUG) and Timed 10-meter walk test (10MWT), the time significantly decreased in both groups, and there was a more significant decrease in the HRS exercise group than in the ball exercise group. [Conclusion] The results of this study indicate that HRS and ball exercises may improve the balance and gait ability of elderly people hospitalized in nursing homes or geriatric hospitals. PMID:24396203

On the temperature dependence of H-U{sub iso} in the riding hydrogen model

Energy Technology Data Exchange (ETDEWEB)

Lübben, Jens; Volkmann, Christian [Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, D-37077 Göttingen (Germany); Grabowsky, Simon [School of Chemistry and Biochemistry, Stirling Highway 35, WA-6009 Crawley (Australia); Edwards, Alison [Bragg Institute, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Morgenroth, Wolfgang [Institut für Geowissenschaften, Abteilung Kristallographie, Goethe-Universität, Altenhöferallee 1, 60438 Frankfurt am Main (Germany); Fabbiani, Francesca P. A. [GZG, Abteilung Kristallographie, Georg-August Universität, Goldschmidtstrasse 1, 37077 Göttingen (Germany); Sheldrick, George M. [Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, D-37077 Göttingen (Germany); Dittrich, Birger, E-mail: birger.dittrich@chemie.uni-hamburg.de [Institut für Anorganische und Angewandte Chemie, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany); Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, D-37077 Göttingen (Germany)

2014-07-01

The temperature dependence of hydrogen U{sub iso} and parent U{sub eq} in the riding hydrogen model is investigated by neutron diffraction, aspherical-atom refinements and QM/MM and MO/MO cluster calculations. Fixed values of 1.2 or 1.5 appear to be underestimated, especially at temperatures below 100 K. The temperature dependence of H-U{sub iso} in N-acetyl-l-4-hydroxyproline monohydrate is investigated. Imposing a constant temperature-independent multiplier of 1.2 or 1.5 for the riding hydrogen model is found to be inaccurate, and severely underestimates H-U{sub iso} below 100 K. Neutron diffraction data at temperatures of 9, 150, 200 and 250 K provide benchmark results for this study. X-ray diffraction data to high resolution, collected at temperatures of 9, 30, 50, 75, 100, 150, 200 and 250 K (synchrotron and home source), reproduce neutron results only when evaluated by aspherical-atom refinement models, since these take into account bonding and lone-pair electron density; both invariom and Hirshfeld-atom refinement models enable a more precise determination of the magnitude of H-atom displacements than independent-atom model refinements. Experimental efforts are complemented by computing displacement parameters following the TLS+ONIOM approach. A satisfactory agreement between all approaches is found.

Co-evolution of three mega-trends nurtures un-captured GDP : Uber's ride-sharing revolution

OpenAIRE

Watanabe, Chihiro; Naveed, Kashif; Neittaanmäki, Pekka

2016-01-01

Uber used a disruptive business model driven by digital technology to trigger a ride-sharing revolution. The institution- al sources of the company’s platform ecosystem architecture were analyzed to explain this revolutionary change. Both an empirical analysis of a co-existing development trajectory with taxis and institutional enablers that helped to create Uber’s platform ecosystem were analyzed. The analysis identified a correspondence with the “two-faced” nature of ICT that nu...

Thermal Optimized Operation of the Single-Phase Full-Bridge PV Inverter under Low Voltage Ride-Through Mode

DEFF Research Database (Denmark)

Wang, Huai; Yang, Yongheng; Blaabjerg, Frede

2013-01-01

The efficiency of 98% has been reported on transformer-less photovoltaic (PV) inverters and the penetration of grid-connected PV systems is booming as well. In the future, the PV systems are expected to contribute to the grid stability by means of low voltage ride-through operation and grid suppo...