WorldWideScience

Sample records for bicyclic heterocycles application

  1. Selenium-Containing Fused Bicyclic Heterocycle Diselenolodiselenole: Field Effect Transistor Study and Structure-Property Relationship.

    Science.gov (United States)

    Debnath, Sashi; Chithiravel, Sundaresan; Sharma, Sagar; Bedi, Anjan; Krishnamoorthy, Kothandam; Zade, Sanjio S

    2016-07-20

    The first application of the diselenolodiselenole (C4Se4) heterocycle as an active organic field effect transistor materials is demonstrated here. C4Se4 derivatives (2a-2d) were obtained by using a newly developed straightforward diselenocyclization protocol, which includes the reaction of diynes with selenium powder at elevated temperature. C4Se4 derivatives exhibit strong donor characteristics and planar structure (except 2d). The atomic force microscopic analysis and thin-film X-ray diffraction pattern of compounds 2a-2d indicated the formation of distinct crystalline films that contain large domains. A scanning electron microscopy study of compound 2b showed development of symmetrical grains with an average diameter of 150 nm. Interestingly, 2b exhibited superior hole mobility, approaching 0.027 cm(2) V(-1) s(-1) with a transconductance of 9.2 μS. This study correlate the effect of π-stacking, Se···Se intermolecular interaction, and planarity with the charge transport properties and performance in the field effect transistor devices. We have shown that the planarity in C4Se4 derivatives was achieved by varying the end groups attached to the C4Se4 core. In turn, optoelectronic properties can also be tuned for all these derivatives by end-group variation. PMID:27353123

  2. Synthesis, Chemistry, and Applications of Heterocyclic Cage Compounds (V)

    Institute of Scientific and Technical Information of China (English)

    WU Hsien-Jen; LIN HuiChang; WANG ZhongYi; WU ChungYi

    2001-01-01

    @@ The synthesis and chemistry of polycyclic of cage compounds have attracted considerable attention in recent years. The vast majority of the work reported in this area has dealt with carbocylic cage compounds. On the other hand, the synthesis and chemistry of heterocyclic cage compounds have received less attention. Recently, we envisioned that studies on the synthesis and chemistry of heterocyclic cage compounds can greatly expand the scopes and utilities of cage compounds.1 As part of a program that involves the synthesis, chemistry, and application of heterocyclic cage compounds, we report here the synthesis of new thia-oxa-cage compounds and the chemical nature of these thia-cages.

  3. Development of New Chiral Bicyclic Ligands : Applications in Catalytic Asymmetric Transfer Hydrogenation, Epoxidations, and Epoxide Rearrangements

    OpenAIRE

    Gayet, Arnaud

    2005-01-01

    This thesis describes the synthesis and application of new chiral bicyclic ligands and their application in asymmetric catalysis. The studies involved: [i] The development of novel chiral bicyclic amino sulfur ligands and their use in transfer hydrogenation. [ii] The development of the kinetic resolution of racemic epoxide through the use of chiral lithium amides. [iii] The synthesis and application of chiral bicyclic amine in the organocatalysed epoxidation of alkenes. [iv] Development and a...

  4. Synthesis, Chemistry, and Applications of Heterocyclic Cage Compounds (V)

    Institute of Scientific and Technical Information of China (English)

    WU; Hsien-Jen

    2001-01-01

    The synthesis and chemistry of polycyclic of cage compounds have attracted considerable attention in recent years. The vast majority of the work reported in this area has dealt with carbocylic cage compounds. On the other hand, the synthesis and chemistry of heterocyclic cage compounds have received less attention. Recently, we envisioned that studies on the synthesis and chemistry of heterocyclic cage compounds can greatly expand the scopes and utilities of cage compounds.1 As part of a program that involves the synthesis, chemistry, and application of heterocyclic cage compounds, we report here the synthesis of new thia-oxa-cage compounds and the chemical nature of these thia-cages.  ……

  5. Big Bicycle Data Processing: from Personal Data to Urban Applications

    Science.gov (United States)

    Pettit, C. J.; Lieske, S. N.; Leao, S. Z.

    2016-06-01

    Understanding the flows of people moving through the built environment is a vital source of information for the planners and policy makers who shape our cities. Smart phone applications enable people to trace themselves through the city and these data can potentially be then aggregated and visualised to show hot spots and trajectories of macro urban movement. In this paper our aim is to develop procedures for cleaning, aggregating and visualising human movement data and translating this into policy relevant information. In conducting this research we explore using bicycle data collected from a smart phone application known as RiderLog. We focus on the RiderLog application initially in the context of Sydney, Australia and discuss the procedures and challenges in processing and cleaning this data before any analysis can be made. We then present some preliminary map results using the CartoDB online mapping platform where data are aggregated and visualised to show hot spots and trajectories of macro urban movement. We conclude the paper by highlighting some of the key challenges in working with such data and outline some next steps in processing the data and conducting higher volume and more extensive analysis.

  6. Bicycle sharing system: role, effects and application to Plymouth

    OpenAIRE

    Wiersma, Bouke

    2010-01-01

    Abstract This thesis investigates the role and effects of a bicycle sharing system, and studies the feasi-bility of such a system in Plymouth. The research consists of a literature review, policy dis-cussion, case studies, and a detailed assessment of t

  7. Design Analysis And Applications Of A Regenerative Bicycle Ergometer

    Directory of Open Access Journals (Sweden)

    Chukwuneke J. L.

    2015-08-01

    Full Text Available Man needs to do some form of physical work in other to remain healthy this work is similar to the work done by any machine or equipment and thus should be channeled to give useful output but rather it is usually dissipated into the environment in form of heat. The regenerative bicycle ergometer takes advantage of the greater power generated by the limbs and arms thus conserves converts and stores the energy dissipated by the rider with an ideal mechanical advantage of 7.6 it strategically uses simple mechanisms to magnify its work and then converts this mechanical energy into electrical energy by the use of a dynamo with a speed ratio of 108.5 and a transmission efficiency of 89 the rider pedals 27rpm to obtain the dynamos rated input of 2600rpm giving an output of 12.6volts. The regenerative bicycle ergometer is designed and constructed to perform all the core functions of a bicycle ergometer having an allowable load of 116.5kg and a maximum resistance of 65.33N which is equivalent to a mass of 6.66kg. The energy converted is stored in a 12volts battery making its use flexible clean and meeting the energy demands of man.

  8. Design Analysis And Applications Of A Regenerative Bicycle Ergometer

    OpenAIRE

    Chukwuneke J. L.; Ugwuegbu D. C.; Sinebe J. E.; Enyi L. C.

    2015-01-01

    Man needs to do some form of physical work in other to remain healthy this work is similar to the work done by any machine or equipment and thus should be channeled to give useful output but rather it is usually dissipated into the environment in form of heat. The regenerative bicycle ergometer takes advantage of the greater power generated by the limbs and arms thus conserves converts and stores the energy dissipated by the rider with an ideal mechanical advantage of 7.6 it strategically use...

  9. Epicyclic Gear Train Solution Techniques with Application to Tandem Bicycling

    OpenAIRE

    Corey, Christopher A.

    2003-01-01

    This thesis presents a unification of kinematic and force-based methods for the design and analysis of planetary gear trains along with a discussion of potential applications in tandem biking. Specifically, this thesis will provide a simple solution technique for the general case of a two-degree of freedom (2DOF) planetary gear train along with new graphical design aids. It will also address the use of epicyclic gear trains as a power coupling in a tandem bike. In the current literature, p...

  10. Bicycle Commuting

    OpenAIRE

    Heinen, E

    2011-01-01

    Cycling is cheaper, healthier and in urban environments often faster than other transport modes. Nevertheless, even at short distances, many individuals do not cycle. This thesis aims to explain why commuters vary in their decision to bicycle. Results indicate that the individual (day-to-day) choice to commute by bicycle is affected by personal attitudes towards cycling to work, social norms, work situation, weather conditions and trip characteristics. Additionally, this thesis provides evide...

  11. Bicycling injuries.

    Science.gov (United States)

    Silberman, Marc R

    2013-01-01

    Bicycling injuries can be classified into bicycle contact, traumatic, and overuse injuries. Despite the popularity of cycling, there are few scientific studies regarding injuries. Epidemiological studies are difficult to compare due to different methodologies and the diverse population of cyclists studied. There are only three studies conducted on top level professionals. Ninety-four percent of professionals in 1 year have experienced at least one overuse injury. Most overuse injuries are mild with limited time off the bike. The most common site of overuse injury is the knee, and the most common site of traumatic injury is the shoulder, with the clavicle having the most common fracture. Many overuse and bicycle contact ailments are relieved with simple bike adjustments.

  12. The application of catalytic ring-closing olefin metathesis to the synthesis of unsaturated oxygen heterocycles

    Energy Technology Data Exchange (ETDEWEB)

    Fu, G.C.; Grubbs, R.H. [California Institute of Technology, Pasadena, CA (United States)

    1992-06-17

    The development of general approaches to carbon-carbon bond formation represents an important ongoing challenge for synthetic organic chemists. One efficient method for constructing carbon-carbon double bonds, the transition metal alkylidene-catalyzed olefin metathesis reaction, has been the focus of intense interest in recent years from the standpoint of both mechanism and polymer synthesis, in contrast, use of this transformation in organic synthesis has been limited. As part of a broader program directed toward establishing transition metal alkylidenes as versatile reagents for organic chemistry, the authors report the successful application of catalytic olefin methathesis to the generation of a variety of unsaturated oxygen heterocycles. 13 refs., 1 fig., 1 tab.

  13. Bicycle accidents.

    Science.gov (United States)

    Lind, M G; Wollin, S

    1986-01-01

    Information concerning 520 bicycle accidents and their victims was obtained from medical records and the victims' replies to questionnaires. The analyzed aspects included risk of injury, completeness of accident registrations by police and in hospitals, types of injuries and influence of the cyclists' age and sex, alcohol, fatigue, hunger, haste, physical disability, purpose of cycling, wearing of protective helmet and other clothing, type and quality of road surface, site of accident (road junctions, separate cycle paths, etc.) and turning manoeuvres.

  14. Solar Bicycle

    OpenAIRE

    S. Sridhar; HARSHENDRA. N. SHET. K

    2011-01-01

    The running costs of the present vehicles are rising day by day hence common man is looking for an alternate mode of transport, with low fuel and maintenance cost. Solar bicycle is an attempt to meet these needs. It is an environmentally sustainable and zero running cost vehicle. It uses photovoltaic cells to absorb energy from sunlight. The absorbed energy is stored in battery. The hub motor mounted on the rear wheel uses this energy to run the cycle. A fully charged battery gives a mileage ...

  15. Solar Bicycle

    Directory of Open Access Journals (Sweden)

    SRIDHAR. S

    2011-07-01

    Full Text Available The running costs of the present vehicles are rising day by day hence common man is looking for an alternate mode of transport, with low fuel and maintenance cost. Solar bicycle is an attempt to meet these needs. It is an environmentally sustainable and zero running cost vehicle. It uses photovoltaic cells to absorb energy from sunlight. The absorbed energy is stored in battery. The hub motor mounted on the rear wheel uses this energy to run the cycle. A fully charged battery gives a mileage of 15-20 km. It is also provided with manual pedaling which increases the cycle’s mileage further. Average speed of the cycle is 15-18 kmph.

  16. Fusing porphyrins with polycyclic aromatic hydrocarbons and heterocycles for optoelectronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Mark E.; Diev, Viacheslav; Hanson, Kenneth; Forrest, Stephen R.

    2015-08-18

    A compound that can be used as a donor material in organic photovoltaic devices comprising a non-activated porphyrin fused with one or more non-activated polycyclic aromatic rings or one or more non-activated heterocyclic rings can be obtained by a thermal fusion process. The compounds can include structures of Formula I: ##STR00001## By heating the reaction mixture of non-activated porphyrins with non-activated polycyclic aromatic rings or heterocyclic rings to a fusion temperature and holding for a predetermined time, fusion of one or more polycyclic rings or heterocyclic rings to the non-activated porphyrin core in meso,.beta. fashion is achieved resulting in hybrid structures containing a distorted porphyrin ring with annulated aromatic rings. The porphyrin core can be olygoporphyrins.

  17. Applications of multicomponent reactions to the synthesis of diverse heterocyclic scaffolds.

    Science.gov (United States)

    Sunderhaus, James D; Martin, Stephen F

    2009-01-01

    The sequencing of multicomponent reactions (MCRs) and subsequent cyclization reactions is a powerful stratagem for the rapid synthesis of diverse heterocyclic scaffolds. The optimal MCR is sufficiently flexible that it can be employed to generate adducts bearing a variety of functional groups that may then be selectively paired to enable different cyclization manifolds, thereby leading to a diverse collection of products. The growing interest in diversity-oriented synthesis has led to increased attention to this paradigm for library synthesis, which has inspired many advances in the design and implementation of MCRs for the construction of diverse heterocyclic scaffolds. PMID:19132705

  18. Lost Kingdom of Bicycles?

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    For most people born in the 1950s and '60s, the bicycle was a faithful companion of their youth, when China was known as a kingdom of bicycles. A bicycle ride was a favorite pastime during a colorful spring day or in the crisp

  19. A Survey on Energy Efficient Wireless Sensor Networks for Bicycle Performance Monitoring Application

    Directory of Open Access Journals (Sweden)

    Sadik Kamel Gharghan

    2014-01-01

    Full Text Available Wireless sensor networks (WSNs have greatly advanced in the past few decades and are now widely used, especially for remote monitoring; the list of potential uses seems endless. Three types of wireless sensor technologies (Bluetooth, ZigBee, and ANT have been used to monitor the biomechanical and physiological activities of bicycles and cyclists, respectively. However, the wireless monitoring of these activities has faced some challenges. The aim of this paper is to highlight various methodologies for monitoring cycling to provide an effective and efficient way to overcome the various challenges and limitations of sports cycling using wireless sensor interfaces. Several design criteria were reviewed and compared with different solutions for the implementation of current WSN research, such as low power consumption, long distance communications, small size, and light weight. Conclusions were drawn after observing the example of an advanced and adaptive network technology (ANT network highlighting reduced power consumption and prolonged battery life. The power saving achieved in the slave node was 88–95% compared to the similar ANT protocol used in the medical rehabilitation.

  20. Synthesis and Radiolabeling of Modified Peptides Attached to Heterocyclic Rings and Their Possible Medical Applications

    International Nuclear Information System (INIS)

    Keeping in mind the pharmacological potential of heterocyclic rings as well as the advantage of biodegradability and biocompatibility of amino acids/peptides, in this thesis we were prompted for the following: 1. Synthesis of novel dipeptide derivatives coupled with different heterocyclic rings (pyridine, 1,2,4-triazol-pyridine, 1,3,4-oxadiazolpyridine and tetrazol-pyridine rings). 2. Characterization of the synthesized compounds on the basis of their spectral data (IR, Mass and 1 H-NMR spectra). 3. Study their antimicrobial activity as one of their expected biological activities. 4. Study the radioiodination of some synthesized dipeptide derivatives. 5. Study the biodistribution of the radiolabeled compounds in normal mice as preliminary studies for the possibility of using them as agents for imaging and treatment.

  1. Synthesis, spectroscopic properties and applications of novel N-heterocycle-containing benzotriazoles as UV absorbers

    Institute of Scientific and Technical Information of China (English)

    Zhi Hua Cui; Xi Dong Wang; Jiang Chao Guo; Wei Guo Chen

    2012-01-01

    Two novel N-heterocycle-containing benzotriazole compounds,5-(5-chloro-2-benzotriazolyl)-6-hydroxy-l,4-dimethyl-3-car-bonitrile-2-pyridone (2) and 4-(5-chloro-2-benzotriazolyl)-5-methyl-2-phenyl-3-pyrazolone (4),were synthesized from reactant 4-chloro-2-nitroaniline via diazotization,azo coupling,reductive cyclization and acidification.Their structures were confirmed by FT-IR,1H NMR,mass spectroscopy and elemental analysis.Their spectral properties were investigated and compared with that of a common commercial benzotriazole UV absorber Tinuvin 326.It is found that the novel N-heterocycle-containing benzotriazole compounds exhibit sharp single peak in the range of 280-400 nm and have much higher molar extinction coefficients than that of Tinuvin 326.Their anti-UV protection properties on polyester fabric were also evaluated and compound 4 was much superior to compound 2 due to its higher exhaustion.

  2. Applications of Multicomponent Reactions to the Synthesis of Diverse Heterocyclic Scaffolds

    OpenAIRE

    Sunderhaus, James D.; Martin, Stephen F.

    2009-01-01

    The sequencing of multicomponent reactions (MCRs) and subsequent cyclization reactions is a powerful stratagem for the rapid synthesis of diverse heterocyclic scaffolds. The optimal MCR is sufficiently flexible that it can be employed to generate adducts bearing a variety of functional groups that may then be selectively paired to enable different cyclization manifolds, thereby leading to a diverse collection of products. The growing interest in diversity-oriented synthesis has led to increas...

  3. Cu and Pd complexes of N-heterocyclic carbenes : catalytic applications as single and dual systems

    OpenAIRE

    Lesieur, Mathieu

    2015-01-01

    Nowadays, the requirement to design highly valuable compounds is undoubtedly one of the major challenges in the field of organic and organometallic chemistry. The use of the versatile and efficient N-heterocyclic carbenes (NHCs) combined with transition metals represents a key feature in modern organometallic chemistry and homogeneous catalysis. In the course of this thesis, the straightforward design and synthesis of a library of Pd(0) bearing NHC ligands was achieved. Their catalytic per...

  4. The flow synthesis of heterocycles for natural product and medicinal chemistry applications.

    Science.gov (United States)

    Baumann, Marcus; Baxendale, Ian R; Ley, Steven V

    2011-08-01

    This article represents an overview of recent research from the Innovative Technology Centre in the field of flow chemistry which was presented at the FROST2 meeting in Budapest in October 2009. After a short introduction of this rapidly expanding field, we discuss some of our results with a main focus on the synthesis of heterocyclic compounds which we use in various natural product and medicinal chemistry programmes.

  5. IMPORTANCE OF HETEROCYCLIC CHEMISTRY: A REVIEW

    Directory of Open Access Journals (Sweden)

    Pragi Arora et a;l

    2012-09-01

    Full Text Available Heterocyclic compounds are of very much interest in our daily life. Heterocyclic compounds have one or more hetero atoms in their structure. They may be cyclic or non cyclic in nature. Heterocyclic compunds have a wide range of application. They are predominantly used as pharmaceuticals, as agrochemicals and as veterinary products. They also find applications as sanitizers, developers, antioxidants, as corrosion inhibitors, as copolymers, dye stuff. They are used as vehicles in the synthesis of other organic compunds. Some of the natural products e.g. antibiotics such as penicillin’s, cephalosporin; alkaloids such as vinblastine, morphine, reserpine etc. have heterocyclic moiety.

  6. Development and Applications of Transesterification Reactions Catalyzed by N-Heterocyclic Olefins.

    Science.gov (United States)

    Blümel, Marcus; Noy, Janina-Miriam; Enders, Dieter; Stenzel, Martina H; Nguyen, Thanh V

    2016-05-01

    A novel method to utilize N-heterocyclic olefins (NHOs), the alkylidene derivatives of N-heterocycic carbenes, as organocatalysts to promote transesterification reactions has been developed. Because of their strong Brønsted/Lewis basicity, NHOs can enhance the nucleophilicity of alcohols for their acylation reactions with carboxylic esters. This transformation can be employed in industrially relevant processes such as the production of biodiesel, the depolymerization of polyethylene terephthalate (PET) from plastic bottles for recycling purposes, and the ring-opening polymerization of cyclic esters to form biodegradable polymers such as polylactide (PLA) and polycaprolactone (PCL). PMID:27115463

  7. Application of flow pattern heart rate test system in electric bicycle%流谱心率系统在电动自行车上的应用

    Institute of Scientific and Technical Information of China (English)

    崔立宝; 于新昌; 崔悦; 尔洪斌; 于红丽

    2013-01-01

    介绍了心率监控系统在电动自行车上的应用,在骑行电动自行车过程中,通过车把传感器进行心率实时监控,当骑行人心率体征发生变化时系统可以及时报警,减少因为骑行人体征变化引起的交通事故,从而引领人们健康生活的理念。%The application of heart rate monitoring system in electric bicycle is introduced. In the process of riding electric bicycle,the rate is real-time monitored by the handlebar sensor,it can timely alarm when the heart rate and signs of the rider changed,thus reduce the traffic accident. Then lead the concept of healthy life for people.

  8. A Comparison of Static and Dynamic Measures of Lower Limb Joint Angles in Cycling: Application to Bicycle Fitting

    Directory of Open Access Journals (Sweden)

    Bini Rodrigo Rico

    2016-03-01

    Full Text Available Purpose. Configuration of bicycle components to the cyclist (bicycle fitting commonly uses static poses of the cyclist on the bicycle at the 6 o’clock crank position to represent dynamic cycling positions. However, the validity of this approach and the potential use of the different crank position (e.g. 3 o’clock have not been fully explored. Therefore, this study compared lower limb joint angles of cyclists in static poses (3 and 6 o’clock compared to dynamic cycling. Methods. Using a digital camera, right sagittal plane images were taken of thirty cyclists seated on their own bicycles mounted on a stationary trainer with the crank at 3 o’clock and 6 o’clock positions. Video was then recorded during pedalling at a self-selected gear ratio and pedalling cadence. Sagittal plane hip, knee and ankle angles were digitised. Results. Differences between static and dynamic angles were large at the 6 o’clock crank position with greater mean hip angle (4.9 ± 3°, smaller knee angle (8.2 ± 5° and smaller ankle angle (8.2 ± 5.3° for static angles. Differences between static and dynamic angles (< 1.4° were trivial to small for the 3 o’clock crank position. Conclusions. To perform bicycle fitting, joint angles should be measured dynamically or with the cyclist in a static pose at the 3 o’clock crank position.

  9. Bicycle Detection System

    OpenAIRE

    Yu, James; Arellano , Secundino; Carrillo , Alma; Cruz , Melinda; Kunitskiy, Dmitriy; Maynigo , Marlo; Sell , Monica

    2013-01-01

    Project Description:  Bicycle detection has become a popular feature of high demand in cities and agencies across the United States. California has recently mandated that all new limit line detector installations as well as modifications to existing limit line detection must provide bicycle detection. This has created the need to develop detection methodologies which are able to detect bicycles as well as differentiate them from vehicles. The objective of this project is to utilize Econolite ...

  10. Recumbent bicycle design

    OpenAIRE

    Basso Puig, Carlos

    2014-01-01

    The subject of this project is the design of a recumbent bicycle prototype. A recumbent bike is a type of bicycle in which the rider mounts in a reclined position. In order to do this, we will learn about these bicycles by showing the different types there are, its evolution over the years, and so on. After that, it is shown the recumbent bicycle design and all its components. It has been invented the frame and so, it is explained the material choice, a brief anthropometric study and FE...

  11. A wearable ECG-HR detector and its application to automatic assist-mode selection of an electrically assisted bicycle.

    Science.gov (United States)

    Ueno, Akinori; Miyashita, Osamu; Yoshida, Toshiya; Yamamoto, Junichi; Lataire, Philippe

    2011-01-01

    Recently, an electrically assisted bicycle has been widely used in daily life and becomes very popular. The user selects the stepwise assist-mode to determine the assistive torque for pleasurable running. From the viewpoint of improvement of health by exercise, the electrically assisted bicycle can be an exercise machine like a treadmill. The heart rate (HR) is regarded as an indication of exercise load. This paper presents an automatic assist-mode selection system based on the HR of the bicycle user. The HR is obtained from the R-waves measured by the proposed wearable electrocardiograph on the user. The mode-selection system is simply implemented by a personal computer, USB-connected interface, and some electronic switching circuits. The running experiments confirm that the proposed assist-mode selection method has practicability. PMID:22255925

  12. Heterocyclic Polymers Perspectives in Nanolayers of Donor Acceptor Heterojunction for Organic Photovoltaic Application

    Directory of Open Access Journals (Sweden)

    M.N. Orlova

    2015-12-01

    Full Text Available The possibility of molecular structural design provides a wide field for engineers to generate interest to heterocyclic structures based on die-perylene and naphthoyl, the possible combinations for the superposition of the absorption spectra. From this point of view, the creation of optically active polymers based on polybenzomidazofenantroline (PBF, 1, 4, 5, 8- naphthalene tetracarboxylic and 3, 4, 9, 10- perylenetetracarboxylic acids opens new opportunities in this important field of science and technology. The results are high absorption in visible spectrum and ability of morphology improvement. Advantages in the optical properties PPBI-O and PNBI-O above the target prototype P3HT, namely a peak absorption in the region of 555 nm to 700 nm red edge are detected.

  13. Bicycle Safety in Action.

    Science.gov (United States)

    National Commission on Safety Education, Washington, DC.

    This material was designed to assist schools in teaching bicycle safety. As the population grows and competition for road space increases, it is more imperative than ever that we concentrate attention on the need for caution among pupil cyclists. The pamphlet: (1) discusses the role of bicycle safety in classroom instruction and in student…

  14. Butchers and Bicycles

    DEFF Research Database (Denmark)

    Kahle, Lynn; Eriksen, Steen Mandsfelt

    2016-01-01

    Morten Wagener is a Danish design, and innovator who founded the cargo and personal transportation bicycle company, ”Butchers and Bicycles,”. He identified a business opportunity to improve the future of urban transport. His idea was that most of the trikes) on the market lacked good design, mane...

  15. Bicycling and Hostels.

    Science.gov (United States)

    Kyle, George M., Ed.

    1974-01-01

    This collection of articles focuses on bicycling and hosteling as important recreational activities that can (a) help conserve energy, (b) benefit the economy offering a low-cost pasttime, and (c) stimulate foreign travel to the U.S. Articles include the following: (a) "Bicycling and Hosteling--An American Partnership," (b) "The Return of the…

  16. Bicycles made to measure

    NARCIS (Netherlands)

    Van Dijk, T.

    2007-01-01

    For almost a century and a half, mathematicians have been racking their brains about the bike. How can a rolling bicycle be so stable of its own accord? Delft researchers now say they have completed the model to end all models. Bicycle manufacturer Batavus intends to use it to make better bikes for

  17. A REVIEW ARTICLE ON IMPORTANCE OF HETEROCYCLIC COMPOUNDS

    Directory of Open Access Journals (Sweden)

    SOURAV DE

    2016-04-01

    Full Text Available Heterocyclic compounds are of very much interest in our daily life. Heterocyclic compounds have one or more heteroatoms in their structure. They may be cyclic or non-cyclic in nature. Heterocyclic compounds have a wide range of application. They are predominantly used as pharmaceuticals, agrochemicals, and veterinary products. They also find applications as sanitizers, developers, antioxidants, corrosion inhibitors, copolymers, dyestuff. They are used as vehicles in the synthesis of other organic compounds. Some of the natural products e.g. antibiotics such as penicillin’s, cephalosporin; alkaloids such as vinblastine, morphine, reserpine etc. have heterocyclic moiety. More than 90% of new drugs contain heterocycles and the interface between chemistry and biology, at which so much new scientific insight, discovery, and application is taking place is crossed by heterocyclic compounds. This review article covers the most active heterocycles that have shown considerable biological actions such as antibiotic, antifungal, anti-inflammatory, antiviral, anticancer, anticonvulsant, anthelmintic, antihistamine, antidepressant activities.

  18. Butchers and Bicycles

    OpenAIRE

    Kahle, Lynn; Eriksen, Steen Mandsfelt

    2016-01-01

    Morten Wagener is a Danish design, and innovator who founded the cargo and personal transportation bicycle company, ”Butchers and Bicycles,”. He identified a business opportunity to improve the future of urban transport. His idea was that most of the trikes) on the market lacked good design, maneuverability and styling. With his engineering and design background, Wagener set out to design a new trike; which would meet the needs of the target market, which his research identified as well- educ...

  19. Synthesis, characterization and applications of some novel mordent and heterocyclic disperse dyes on polyester and wool fibers

    Directory of Open Access Journals (Sweden)

    Hitendra Mangubhai Patel

    2012-10-01

    Full Text Available The novel mordent and disperse heterocyclic dyes were prepared by coupling of various diazo solution of aromatic amines with 1-[(2-butyl-2,3-dihydrobenzofuran-3-yl]-1-(4-hydroxyphenylmethanone. The resultant mordent and disperse heterocyclic dyes were characterized by elemental analyses, IR and 1H-NMR and 13C-NMR spectral studies. The UV-visible spectral data have also been discussed in terms of structural property relationship. The dyeing assessment of all the mordent and disperse heterocyclic dyes was evaluated on wool and polyester textile fibers. The results of antibacterial studies of chrome pretreated fabrics revealed that the toxicity of mordented dyes against Escherichia coli, Staphylococcus aureus, Salmonella typhi, Bacillus subtilis bacteria was fairly good.

  20. A REVIEW ARTICLE ON IMPORTANCE OF HETEROCYCLIC COMPOUNDS

    OpenAIRE

    SOURAV DE; NIRANJAN BABU M; SUNEEL BABU T; BHAVYA SREE R; SAI KIRAN A; K SUNIL KUMAR REDDY

    2016-01-01

    Heterocyclic compounds are of very much interest in our daily life. Heterocyclic compounds have one or more heteroatoms in their structure. They may be cyclic or non-cyclic in nature. Heterocyclic compounds have a wide range of application. They are predominantly used as pharmaceuticals, agrochemicals, and veterinary products. They also find applications as sanitizers, developers, antioxidants, corrosion inhibitors, copolymers, dyestuff. They are used as vehicles in the synthesis of other org...

  1. Cationic bis-N-heterocyclic carbene (NHC) ruthenium complex: Structure and application as latent catalyst in olefin metathesis

    KAUST Repository

    Rouen, Mathieu

    2014-09-11

    An unexpected cationic bis-N-heterocyclic carbene (NHC) benzylidene ether based ruthenium complex (2 a) was prepared through the double incorporation of an unsymmetrical unsaturated N-heterocyclic carbene (U2-NHC) ligand that bore an N-substituted cyclododecyl side chain. The isolation and full characterization (including X-ray diffraction studies) of key synthetic intermediates along with theoretical calculations allowed us to understand the mechanism of the overall cationization process. Finally, the newly developed complex 2 a displayed interesting latent behavior during ring-closing metathesis, which could be "switched on" under acidic conditions.

  2. Synthesis, characterization and applications of some novel mordent and heterocyclic disperse dyes on polyester and wool fibers

    OpenAIRE

    Hitendra Mangubhai Patel

    2012-01-01

    The novel mordent and disperse heterocyclic dyes were prepared by coupling of various diazo solution of aromatic amines with 1-[(2-butyl-2,3-dihydrobenzofuran-3-yl)]-1-(4-hydroxyphenyl)methanone. The resultant mordent and disperse heterocyclic dyes were characterized by elemental analyses, IR and 1H-NMR and 13C-NMR spectral studies. The UV-visible spectral data have also been discussed in terms of structural property relationship. The dyeing assessment of all the mordent and di...

  3. Cationic bis-N-heterocyclic carbene (NHC) ruthenium complex: structure and application as latent catalyst in olefin metathesis.

    Science.gov (United States)

    Rouen, Mathieu; Queval, Pierre; Falivene, Laura; Allard, Jessica; Toupet, Loïc; Crévisy, Christophe; Caijo, Frédéric; Baslé, Olivier; Cavallo, Luigi; Mauduit, Marc

    2014-10-13

    An unexpected cationic bis-N-heterocyclic carbene (NHC) benzylidene ether based ruthenium complex (2 a) was prepared through the double incorporation of an unsymmetrical unsaturated N-heterocyclic carbene (U2 -NHC) ligand that bore an N-substituted cyclododecyl side chain. The isolation and full characterization (including X-ray diffraction studies) of key synthetic intermediates along with theoretical calculations allowed us to understand the mechanism of the overall cationization process. Finally, the newly developed complex 2 a displayed interesting latent behavior during ring-closing metathesis, which could be "switched on" under acidic conditions.

  4. Cationic bis-N-heterocyclic carbene (NHC) ruthenium complex: structure and application as latent catalyst in olefin metathesis.

    Science.gov (United States)

    Rouen, Mathieu; Queval, Pierre; Falivene, Laura; Allard, Jessica; Toupet, Loïc; Crévisy, Christophe; Caijo, Frédéric; Baslé, Olivier; Cavallo, Luigi; Mauduit, Marc

    2014-10-13

    An unexpected cationic bis-N-heterocyclic carbene (NHC) benzylidene ether based ruthenium complex (2 a) was prepared through the double incorporation of an unsymmetrical unsaturated N-heterocyclic carbene (U2 -NHC) ligand that bore an N-substituted cyclododecyl side chain. The isolation and full characterization (including X-ray diffraction studies) of key synthetic intermediates along with theoretical calculations allowed us to understand the mechanism of the overall cationization process. Finally, the newly developed complex 2 a displayed interesting latent behavior during ring-closing metathesis, which could be "switched on" under acidic conditions. PMID:25212827

  5. Bicycle Culture in Denmark

    OpenAIRE

    Pedersenn, Pia; Breitenstein, Marcus Lindgaard; Nilsson, Asbjørn Lupo

    2014-01-01

    The research area involves the cycling culture in Denmark. Cycling is one of the main forms of transport in Denmark today, and it has been a big part of Denmark’s culture since the early 20th century. This project specifically looks at bicycle helmets. Today in Denmark, there is no legislation demanding cyclists to wear helmets. However we would like to investigate what the government’s stance is concerning bicycle helmets. The project will begin by looking at the efficiency of helmets. Some ...

  6. Electric Bicycle Design

    OpenAIRE

    Tovar López, Carlos

    2009-01-01

    The thesis consists of the design of an electric bike. Based on the analysis of the needs arising from urban transport in Sweden and its people.We wanted to develop a bicycle that could be manufactured in the coming years and be widely accepted by the Swedish population and later also in Europe.

  7. Bicycles and Valentines

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Shanghai municipality's announcement late last year that bicycles were to be banned from the city's main thoroughfares was ill received by many residents. The measure was taken to relieve traffic congestion and reflects how traditional modes of transport fail to meet the changing needs of Chinese contemporary life.

  8. The safety of electrically assisted bicycles compared to classic bicycles.

    Science.gov (United States)

    Schepers, J P; Fishman, E; den Hertog, P; Wolt, K Klein; Schwab, A L

    2014-12-01

    Use of electrically assisted bicycles with a maximum speed of 25 km/h is rapidly increasing. This growth has been particularly rapid in the Netherlands, yet very little research has been conducted to assess the road safety implications. This case-control study compares the likelihood of crashes for which treatment at an emergency department is needed and injury consequences for electric bicycles to classic bicycles in the Netherlands among users of 16 years and older. Data were gathered through a survey of victims treated at emergency departments. Additionally, a survey of cyclists without any known crash experience, drawn from a panel of the Dutch population acted as a control sample. Logistic regression analysis is used to compare the risk of crashes with electric and classical bicycles requiring treatment at an emergency department. Among the victims treated at an emergency department we compared those being hospitalized to those being send home after the treatment at the emergency department to compare the injury consequences between electric and classical bicycle victims. The results suggest that, after controlling for age, gender and amount of bicycle use, electric bicycle users are more likely to be involved in a crash that requires treatment at an emergency department due to a crash. Crashes with electric bicycles are about equally severe as crashes with classic bicycles. We advise further research to develop policies to minimize the risk and maximize the health benefits for users of electric bicycles.

  9. An electrochemical procedure coupled with a Schiff base method; application to electroorganic synthesis of new nitrogen-containing heterocycles

    Energy Technology Data Exchange (ETDEWEB)

    Dowlati, Bahram; Othman, Mohamed Rozali [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2013-11-27

    The synthesis of Nitrogen-containing heterocycles has been achieved using chemical and electrochemical methods, respectively. The direct chemical synthesis of nucleophiles proceeds through the Schiff base chemical reaction. This procedure offers an alternate reaction between dicarbonyl compounds and diamines leads to the formation of products. The results indicate that the Schiff base chemical method for synthesis of the product has successfully performed in excellent overall yield. In the electrochemical step, a series of Nitrogen-containing compounds were electrosynthesized. Various parameters such as the applied potential, pH of the electrolytic solution, cell configuration and also purification techniques, were carried out to optimize the yields of corresponding products. New Nitrogen-containing heterocycle derivatives were synthesized using an electrochemical procedure coupled with a Schiff base as a facile, efficient and practical method. The products have been characterized after purification by IR, {sup 1}H NMR, {sup 13}C NMR and ESI-MS{sup 2}.

  10. Analysis of heterocyclic aromatic amines.

    Science.gov (United States)

    Murkovic, M

    2007-09-01

    Heterocyclic aromatic amines are formed in protein and amino acid-rich foods at temperatures above 150 degrees C. Of more than twenty heterocyclic aromatic amines identified ten have been shown to have carcinogenic potential. As nutritional hazards, their reliable determination in prepared food, their uptake and elimination in living organisms, including humans, and assessment of associated risks are important food-safety issues. The concentration in foods is normally in the low ng g(-1) range, which poses a challenge to the analytical chemist. Because of the complex nature of food matrixes, clean-up and enrichment of the extracts are also complex, usually involving both cation-exchange (propylsulfonic acid silica gel, PRS) and reversed-phase purification. The application of novel solid-phase extraction cartridges with a wettable apolar phase combined with cation-exchange characteristics simplified this process--both the polar and apolar heterocyclic aromatic amines were recovered in one fraction. Copper phthalocyanine trisulfonate bonded to cotton ("blue cotton") or rayon, and molecular imprinted polymers have also been successfully used for one-step sample clean-up. For analysis of the heterocyclic aromatic amines, liquid chromatography with base-deactivated reversed-phase columns has been used, and, recently, semi-micro and capillary columns have been introduced. The photometric, fluorimetric, or electrochemical detectors used previously have been replaced by mass spectrometers. Increased specificity and sub-ppb sensitivities have been achieved by the use of the selected-reaction-monitoring mode of detection of advanced MS instrumentation, for example the triple quadrupole and Q-TOF instrument combination. Gas chromatography, also with mass-selective detection, has been used for specific applications; the extra derivatization step needed for volatilization has been balanced by the higher chromatographic resolution. PMID:17546447

  11. Electric power generating bicycle

    OpenAIRE

    Brito, Nuno; Ribeiro, Luís; Esteves, João Sena

    2006-01-01

    It is manifest the growing interest in both personal health and environmental issues. The device described on this paper contemplates both aspects: generating environment-friendly electric power while keeping fit. A car alternator excited through a 12V battery is coupled to a mountain bicycle, and this arrangement enables the lighting of six halogen lamps, if a cyclist pedals fast enough. Such a machine gives rise to the thought of a self-powered gymnasium. Considerable physical effort is req...

  12. The Application of TRIZ Theory in the Picnic Buffet Bicycle Design%TRIZ 理论在野餐自助自行车设计中的应用

    Institute of Scientific and Technical Information of China (English)

    辛明远; 张世豪; 张淑颖

    2015-01-01

    According to the application requirements of outdoor bicycle, TRIZ tools such as problem de-scription, technical contradiction analysis are used.According to TRIZ the general path to solve the problem, the applications of comprehensive analysis of invention principles are analyzed.The final solution is formed. Picnic buffet the conceptual design of bicycle is given.%从多人户外自行车的应用需求出发,使用问题描述、技术矛盾分析等TRIZ工具,按照TRIZ解决问题的一般路径,综合分析发明原理应用的可行性,形成最终解决方案,最后给出野餐自助自行车的概念设计。

  13. Synthesis of Heterocycles through a Ruthenium‐Catalyzed Tandem Ring‐Closing Metathesis/Isomerization/N‐Acyliminium Cyclization Sequence

    DEFF Research Database (Denmark)

    Ascic, Erhad; Jensen, Jakob Feldthusen; Nielsen, Thomas Eiland

    2011-01-01

    Tandem bicycle: In the title reaction double bonds created during ring-closing metathesis isomerize to generate reactive iminium intermediates that undergo intramolecular cyclization reactions with tethered heteroatom and carbon nucleophiles. In this way, a series of biologically interesting hete...... heterocyclic compounds can be made, including a known precursor for the total synthesis of the antiparasitic natural product harmicine....

  14. The Bicycle Assembly Line Game

    Science.gov (United States)

    Klotz, Dorothy

    2011-01-01

    "The Bicycle Assembly Line Game" is a team-based, in-class activity that helps students develop a basic understanding of continuously operating processes. Each team of 7-10 students selects one of seven prefigured bicycle assembly lines to operate. The lines are run in real-time, and the team that operates the line that yields the…

  15. Simple direct formation of self-assembled N-heterocyclic carbene monolayers on gold and their application in biosensing.

    Science.gov (United States)

    Crudden, Cathleen M; Horton, J Hugh; Narouz, Mina R; Li, Zhijun; Smith, Christene A; Munro, Kim; Baddeley, Christopher J; Larrea, Christian R; Drevniok, Benedict; Thanabalasingam, Bheeshmon; McLean, Alastair B; Zenkina, Olena V; Ebralidze, Iraklii I; She, Zhe; Kraatz, Heinz-Bernhard; Mosey, Nicholas J; Saunders, Lisa N; Yagi, Akiko

    2016-01-01

    The formation of organic films on gold employing N-heterocyclic carbenes (NHCs) has been previously shown to be a useful strategy for generating stable organic films. However, NHCs or NHC precursors typically require inert atmosphere and harsh conditions for their generation and use. Herein we describe the use of benzimidazolium hydrogen carbonates as bench stable solid precursors for the preparation of NHC films in solution or by vapour-phase deposition from the solid state. The ability to prepare these films by vapour-phase deposition permitted the analysis of the films by a variety of surface science techniques, resulting in the first measurement of NHC desorption energy (158±10 kJ mol(-1)) and confirmation that the NHC sits upright on the surface. The use of these films in surface plasmon resonance-type biosensing is described, where they provide specific advantages versus traditional thiol-based films. PMID:27585494

  16. Simple direct formation of self-assembled N-heterocyclic carbene monolayers on gold and their application in biosensing

    Science.gov (United States)

    Crudden, Cathleen M.; Horton, J. Hugh; Narouz, Mina R.; Li, Zhijun; Smith, Christene A.; Munro, Kim; Baddeley, Christopher J.; Larrea, Christian R.; Drevniok, Benedict; Thanabalasingam, Bheeshmon; McLean, Alastair B.; Zenkina, Olena V.; Ebralidze, Iraklii I.; She, Zhe; Kraatz, Heinz-Bernhard; Mosey, Nicholas J.; Saunders, Lisa N.; Yagi, Akiko

    2016-09-01

    The formation of organic films on gold employing N-heterocyclic carbenes (NHCs) has been previously shown to be a useful strategy for generating stable organic films. However, NHCs or NHC precursors typically require inert atmosphere and harsh conditions for their generation and use. Herein we describe the use of benzimidazolium hydrogen carbonates as bench stable solid precursors for the preparation of NHC films in solution or by vapour-phase deposition from the solid state. The ability to prepare these films by vapour-phase deposition permitted the analysis of the films by a variety of surface science techniques, resulting in the first measurement of NHC desorption energy (158+/-10 kJ mol-1) and confirmation that the NHC sits upright on the surface. The use of these films in surface plasmon resonance-type biosensing is described, where they provide specific advantages versus traditional thiol-based films.

  17. Bicycle Rider Control: Observations, Modeling & Experiments

    NARCIS (Netherlands)

    Kooijman, J.D.G.

    2012-01-01

    Bicycle designers traditionally develop bicycles based on experience and trial and error. Adopting modern engineering tools to model bicycle and rider dynamics and control is another method for developing bicycles. This method has the potential to evaluate the complete design space, and thereby dev

  18. [Prevention of bicycle accidents].

    Science.gov (United States)

    Zwipp, H; Barthel, P; Bönninger, J; Bürkle, H; Hagemeister, C; Hannawald, L; Huhn, R; Kühn, M; Liers, H; Maier, R; Otte, D; Prokop, G; Seeck, A; Sturm, J; Unger, T

    2015-04-01

    For a very precise analysis of all injured bicyclists in Germany it would be important to have definitions for "severely injured", "seriously injured" and "critically injured". By this, e.g., two-thirds of surgically treated bicyclists who are not registered by the police could become available for a general analysis. Elderly bicyclists (> 60 years) are a minority (10 %) but represent a majority (50 %) of all fatalities. They profit most by wearing a helmet and would be less injured by using special bicycle bags, switching on their hearing aids and following all traffic rules. E-bikes are used more and more (145 % more in 2012 vs. 2011) with 600,000 at the end of 2011 and are increasingly involved in accidents but still have a lack of legislation. So even for pedelecs 45 with 500 W and a possible speed of 45 km/h there is still no legislative demand for the use of a protecting helmet. 96 % of all injured cyclists in Germany had more than 0.5 ‰ alcohol in their blood, 86 % more than 1.1 ‰ and 59 % more than 1.7 ‰. Fatalities are seen in 24.2 % of cases without any collision partner. Therefore the ADFC calls for a limit of 1.1 ‰. Some virtual studies conclude that integrated sensors in bicycle helmets which would interact with sensors in cars could prevent collisions or reduce the severity of injury by stopping the cars automatically. Integrated sensors in cars with opening angles of 180° enable about 93 % of all bicyclists to be detected leading to a high rate of injury avoidance and/or mitigation. Hanging lamps reduce with 35 % significantly bicycle accidents for children, traffic education for children and special trainings for elderly bicyclists are also recommended as prevention tools. As long as helmet use for bicyclists in Germany rates only 9 % on average and legislative orders for using a helmet will not be in force in the near future, coming up campaigns seem to be necessary to be promoted by the Deutscher

  19. [Prevention of bicycle accidents].

    Science.gov (United States)

    Zwipp, H; Barthel, P; Bönninger, J; Bürkle, H; Hagemeister, C; Hannawald, L; Huhn, R; Kühn, M; Liers, H; Maier, R; Otte, D; Prokop, G; Seeck, A; Sturm, J; Unger, T

    2015-04-01

    For a very precise analysis of all injured bicyclists in Germany it would be important to have definitions for "severely injured", "seriously injured" and "critically injured". By this, e.g., two-thirds of surgically treated bicyclists who are not registered by the police could become available for a general analysis. Elderly bicyclists (> 60 years) are a minority (10 %) but represent a majority (50 %) of all fatalities. They profit most by wearing a helmet and would be less injured by using special bicycle bags, switching on their hearing aids and following all traffic rules. E-bikes are used more and more (145 % more in 2012 vs. 2011) with 600,000 at the end of 2011 and are increasingly involved in accidents but still have a lack of legislation. So even for pedelecs 45 with 500 W and a possible speed of 45 km/h there is still no legislative demand for the use of a protecting helmet. 96 % of all injured cyclists in Germany had more than 0.5 ‰ alcohol in their blood, 86 % more than 1.1 ‰ and 59 % more than 1.7 ‰. Fatalities are seen in 24.2 % of cases without any collision partner. Therefore the ADFC calls for a limit of 1.1 ‰. Some virtual studies conclude that integrated sensors in bicycle helmets which would interact with sensors in cars could prevent collisions or reduce the severity of injury by stopping the cars automatically. Integrated sensors in cars with opening angles of 180° enable about 93 % of all bicyclists to be detected leading to a high rate of injury avoidance and/or mitigation. Hanging lamps reduce with 35 % significantly bicycle accidents for children, traffic education for children and special trainings for elderly bicyclists are also recommended as prevention tools. As long as helmet use for bicyclists in Germany rates only 9 % on average and legislative orders for using a helmet will not be in force in the near future, coming up campaigns seem to be necessary to be promoted by the Deutscher

  20. Design of an electric bicycle

    OpenAIRE

    Cabré Viñeta, Anna

    2010-01-01

    The purpose of this study is to make an electrical bicycle. As this bike has an electrical motor, it will not be used as a sport method, the main idea is to use it as a public transport so people can move from side to side of the city without traffic, without pollution and without getting tired. Once selected the purpose of the bicycle, it is necessary to take into account the main features that it must have. A bicycle used as a transport around the city needs to be easy to ...

  1. Free Use of Bicycles at CERN

    CERN Multimedia

    2000-01-01

    Imagine you have just arrived at CERN. You are from Russia or Japan and have no car but you do need to get around and do not like depending on public transport. What do you do? You go to the EP Service Point (Building 124) and meet Boris Cabaud to get a CERN bicycle. Use of the bicycle is free but you have to fill in an application form which needs to be signed by your Group or Division Secretary. Then the application is filled in, you are put on the waiting list and it might take you from one to four weeks to get your bike depending on the season. “Normally the bikes are only for Users in the EP division as they are paid for by the EP budget,” says Boris, “but some other divisions have made arrangements to cover the costs.” Boris takes care of 350 bicycles at present. Each bike can be lent for maximum one year. During the winter the bikes can be stored in building 301 as it is difficult to ride them in the snow. If a bike is broken or lost all costs will be billed to the group or team account of the bo...

  2. Control for an Autonomous Bicycle

    OpenAIRE

    Getz, Neil H.; Marsden, J. E.

    1995-01-01

    The control of nonholonomic and underactuated systems with symmetry is illustrated by the problem of controlling a bicycle. We derive a controller which, using steering and rear-wheel torque, causes a model of a riderless bicycle to recover its balance from a near fall as well as converge to a time parameterized path in the ground plane. Our construction utilizes new results for both the derivation of equations of motion for nonholonomic systems with symmetry, as well as the control of undera...

  3. Application of imidazolinium salts and N-heterocyclic olefins for the synthesis of anionic and neutral tungsten imido alkylidene complexes.

    Science.gov (United States)

    Imbrich, Dominik A; Frey, Wolfgang; Naumann, Stefan; Buchmeiser, Michael R

    2016-05-01

    The synthesis, single crystal X-ray structure and activity in olefin metathesis of novel anionic tungsten imido alkylidene complexes [1,3-bis-(2,4,6-trimethylphenyl)imidazolinium](+) [W(N-2,6-iPr2C6H3)(CHCMe2Ph)(2,5-Me2Pyr)2Cl](-), [1,3-bis-(2,4,6-trimethylphenyl)imidazolinium](+) [W(N-2,6-iPr2C6H3)(CHCMe2Ph)(2,5Me2Pyr)2(OC6F5)](-), and [1,3-bis-(2,6-diisopropylphenyl)imidazolinium](+) [W(N-2,6-iPr2C6H3)(CHCMe2Ph)(2,5-Me2Pyr)Cl2](-) are reported. Additionally, the first example of a bis(N-heterocyclic olefinium) alkylidene tungstate, W(N-2,6-iPr2C6H3)(CHCMe2Ph)(2-methylene-1,3,4,5-tetramethyl-imidazoline)2(OTf)2, is described, including preparation, crystal structure and catalytic activity. PMID:27068323

  4. Valuing public investments to support bicycling

    OpenAIRE

    Götschi, Thomas; Hintermann, Beat

    2014-01-01

    We develop a framework for assessing the net benefits of investments to promote bicycling, which explicitly accounts for internal costs of bicycling. We apply our model to eight Swiss cities using data from the Swiss national travel survey and find that increasing the level of bicycling by reducing internal costs leads to inframarginal benefits that exceed the net benefits from the additional bicycling.  We further find that Swiss cyclists only partially internalize health benefits, which aff...

  5. Solar Electric Bicycle Body Modeling and Simulation

    Directory of Open Access Journals (Sweden)

    Zhikun Wang

    2013-10-01

    Full Text Available A new solar electric bicycle design and study were carried out on in this paper. Application of CAD technology to establish three-dimension geometric model, using the kinetic analysis on the frame and other parts for numerical simulation and static strength analysis for the vehicle model design, virtual assembly, complete frame dynamics analysis and vibration analysis, with considering other factors, first on the frame structure improvement, second on security of design calculation analysis and comparison, finally get the ideal body design.

  6. The Bicycle Rental Market In Hangzhou

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    On May 1, 2008, Hangzhou, capital of east China’s Zhejiang Province, included bicycle rentals in the public transportation system. Now, bicycles have become the most convenient form of transport for Hangzhou residents. Data from the Hangzhou Bureau of Transportation show that on average each bicycle gets rented five times a day.

  7. Advances in heterocyclic ketene aminals

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Recent developments in the study of the reactions of heterocyclic ketene aminals are reviewed with the emphases on regioselective alkylation, acylation and glycosylation reactions, and on the aza-ene reactions with α,β-unsaturated compounds, azo and carbonyl compounds. Reactions with 1,3-dipoles and other reagents to synthesize fused heterocycles are also discussed.

  8. Application of TL 494 t o Electrically Powered Bicycle Control%TL494在电动助力车控制中的应用

    Institute of Scientific and Technical Information of China (English)

    王培玲; 臧炜

    2001-01-01

    This paper details the basic performances of the in tegrated circuit of TL 494 switch power pulse width modulator and its applicatio n to bicycle powered by DC motor with br ush and briefs some problems which shoul d be noted in dcsign.%本文较详细介绍了TL 494开关电源脉宽调制器集成电路的基本性能和在有刷直流电动助力车中的应用。简要叙述了设计中应注意的问题。

  9. EP BICYCLE POOL - VIGNETTES 2002

    CERN Multimedia

    EP-SMI Help Desk

    2002-01-01

    The vignettes (insurance certificates) for 2002 become obligatory from 1 June. If you have a bicycle from the EP Pool, please bring it to the EP-SMI Help Desk (Building 124) on any working day up to 31 May between 8h.30 - 12h.00 or 13h.30 - 17h.30. EP-SMI Help Desk

  10. Proper fit of the bicycle.

    Science.gov (United States)

    Burke, E R

    1994-01-01

    After cyclists have carefully made adjustments for proper fit, minor aches and pains may develop before the body adjusts to the new riding posture. This is normal--so resist the temptation to fiddle with the position much. They will become accustomed to the new riding position after a few rides, and cycling performance will be improved. Then they can concentrate on bike handling skills and fitness confident that their riding position is as good as can be. Proper bicycle fit requires careful review of bicycle selection, saddle height for proper leg extension, fore-and-aft positioning of the knee over the pedal, saddle tilt, handlebar position, and positioning of the upper body for optimum comfort and performance. Further research on the effects of maintaining an aerodynamic position for extended periods of time needs to be investigated to review fatigue patterns in lower and upper body musculature. The underlying principle of positioning a cyclist on a bicycle is to remember that the bicycle is adjustable, and the cyclist is adaptable. PMID:8111846

  11. Organic heterocyclic molecules become superalkalis.

    Science.gov (United States)

    Reddy, G Naaresh; Giri, Santanab

    2016-09-21

    An organic molecule which behaves like a superalkali has been designed from an aromatic heterocyclic molecule, pyrrole. Using first-principles calculation and a systematic two-step approach, we can have superalkali molecules with a low ionization energy, even lower than that of Cs. Couple cluster (CCSD) calculation reveals that a new heterocycle, C3N2(CH3)5 derived from a well-known aromatic heterocycle, pyrrole (C4H5N) has an ionization energy close to 3.0 eV. A molecular dynamics calculation on C3N2(CH3)5 reveals that the structure is dynamically stable. PMID:27530344

  12. The Design of Sport Bicycle Speed Odometer

    Directory of Open Access Journals (Sweden)

    Dongbing Liu

    2013-04-01

    Full Text Available As bicycle sport equipment, a sport bike needs a speed and distance measuring device, due to the characteristic of road cycling, thereby mastering the state of motion. According to external conditions such as temperature, wind speed, the bike can make the appropriate adjustment to achieve the best movement effect. The bicycle speed odometer is a major accessibility tool that satisfies with needs of the people with fast development. This study elaborated a bike speed odometer design based on Hall element, taking AT89C52 single chip as the core, measuring speed with A44E Hall sensor, to finish the bike mileage/speed measurement and statistics by displaying bike mileage and speed in real time. By using the Hall elements, the hardware of speed odometer input the number of pulse of per circle into the single-chip computer system. Then the signal processed by the single-chip computer displays. The software is programmed with assembly language and modular design idea. The design of the hardware circuit is simple and the subroutine has universal property, which fully meet the design requirements and possess a wide range of application and dissemination value.

  13. Road characteristics and bicycle accidents.

    Science.gov (United States)

    Nyberg, P; Björnstig, U; Bygren, L O

    1996-12-01

    In Umeå, Sweden, defects in the physical road surface contributed to nearly half of the single bicycle accidents. The total social cost of these injuries to people amount to at least SEK 20 million (SEK 60,000 or about USD 8,500 per accident), which corresponds to the estimated loss of "eight life equivalents a year". Improved winter maintenance seems to have the greatest injury prevention potential and would probably reduce the number of injuries considerably, whereas improved road quality and modification of kerbs would reduce the most severe injuries. A local traffic safety program should try to prevent road accidents instead of handling the consequences of them. In accordance with Parliament decisions on traffic we would like to see increased investment in measures favoring bicycle traffic, where cycling is seen as a solution, not as a problem.

  14. 一种电动自行车控制器程序架构设计%Application Architecture Design of an Electric Bicycle Controller

    Institute of Scientific and Technical Information of China (English)

    胡伯生; 孙瑜

    2015-01-01

    介绍了一种电动自行车用BLDC电机控制器程序架构设计,利用STC15系列单片机独特的PCA模块实现对BLDC电机控制的每一个动作进行精确的设计.在电动自行车上的试验结果表明,按该程序结构设计的BLDC控制器工作稳定,有很好的应用价值.%This paper introduces a program structure design of brushless DC motor control er used on electric bicycle. This design al ows the brushless DC motor control er precisely control every movement of the motor basied on the unique PCA module of STC15 series microcontrol ers.Experiments show that,brushless DC motor works wel .

  15. Characterisation of Electric Bicycles Performances

    OpenAIRE

    Cappelle, Jan; Lataire, Philippe; Maggetto, Gaston; Meeusen, Roman; Kempenaers, Farid

    2002-01-01

    The proposed paper reports on characterisation work performed in the scope of the E-tour project. This project has already been presented at EVS-18. At the ‘Vrije Universiteit Brussel’ different EPACs (Electric Power Assisted Cycles) are put at the public’s disposal for testing. To quantify the performances of these electrical bicycles we want to link the subjective experienced driving comfort to some measurable objective parameters. For this purpose we converted a treadmill in...

  16. Gold-Catalyzed Synthesis of Heterocycles

    Science.gov (United States)

    Arcadi, Antonio

    2014-04-01

    The following sections are included: * Introduction * Synthesis of Heterocycles via Gold-Catalyzed Heteroatom Addition to Unsaturated C-C Bonds * Synthesis of Heterocyclic Derivatives through Gold-Catalyzed Cyclization of Polyunsaturated Compounds * Synthesis of Heterocyclic Compounds via α-Oxo Gold Carbenoid * Synthesis of Heterocyclic Derivatives through Gold-Catalyzed Cycloaddition Reactions * Synthesis of Heterocyclic Derivatives through Gold-Catalyzed Activation of Carbonyl Groups and Alcohols * Synthesis of Heterocyclic Compounds through Gold-Mediated C-H Bond Functionalization * Gold-Catalyzed Domino Cyclization/Oxidative Coupling Reactions * Conclusions * References

  17. Bamboo Bicycle – Past or Future?

    Directory of Open Access Journals (Sweden)

    Suzana Jakovljević

    2016-01-01

    Full Text Available In this article the experiment was carried out to establish tensile strength values of two different bamboo species, which are obtained by the static tensile test. The tensile strength results of two tested species Tonkin Cane and Ku Zhu bamboo are presented and compared with traditional materials used for bicycle frame to determine their suitability for designing a frame. Physiology and other properties of bamboo were elaborated as well. The purpose of this study was to gain more knowledge on bamboo and prove his suitability in use as an alternative for ecologically unacceptable materials. Therefore, application of the natural materials is essential for the sustainable development. The fact that they have unlimited resources the use of bamboo has great potential and this article explains why.

  18. A study on electric bicycle energy efficiency

    Directory of Open Access Journals (Sweden)

    Ivan EVTIMOV

    2015-09-01

    Full Text Available The paper presents a construction of an experimental electric bicycle for evaluation of the energy efficiency. The bicycle is equipped with onboard computer which can store the information about motion and energy consumption. The result concerning power, energy consumption, recharging during brake process, etc. are given. Energy consumption for 3 typical city routes is studied.

  19. Bicycle parking preferences: costs versus walking time

    NARCIS (Netherlands)

    Molin, E.J.E.; Maat, K.

    2014-01-01

    Successful bicycle stimulating policies may increase the need for bicycle parking capacity, especially at main railway stations located in city centers. A potential solution for this problem involves combining paid surveyed indoor parking near the platforms and free open-air parking without surveill

  20. Stabilizing a Bicycle: A Modeling Project

    Science.gov (United States)

    Pennings, Timothy J.; Williams, Blair R.

    2010-01-01

    This article is a project that takes students through the process of forming a mathematical model of bicycle dynamics. Beginning with basic ideas from Newtonian mechanics (forces and torques), students use techniques from calculus and differential equations to develop the equations of rotational motion for a bicycle-rider system as it tips from…

  1. Bicycle helmet use and bicycling-related injury among young Canadians: an equity analysis

    Science.gov (United States)

    2013-01-01

    Introduction Cycling is a major activity for adolescents in Canada and potential differences exist in bicycling-related risk and experience of injury by population subgroup. The overall aim of this study was to inform health equity interventions by profiling stratified analytic methods and identifying potential inequities associated with bicycle-related injury and the use of bicycle helmets among Canadian youth. The two objectives of this study were: (1) To examine national patterns in bicycle ridership and also bicycle helmet use among Canadian youth in a stratified analysis by potentially vulnerable population subgroups, and (2) To examine bicycling-related injury in the same population subgroups of Canadian youth in order to identify possible health inequities. Methods Data for this study were obtained from the 6th cycle (2009/10) of the Health Behaviour in School-aged Children (HBSC) study, which is a general health survey that was completed by 26,078 students in grades 6–10 from 436 Canadian schools. Based on survey responses, we determined point prevalence for bicycle ridership, bicycle helmet use and relative risks for bicycling-related injury. Results Three quarters of all respondents were bicycle riders (n=19,410). Independent factors associated with bicycle ridership among students include being male, being a younger student, being more affluent, and being a resident of a small town. Among bicycle riders, 43% (95%CI ± 0.6%) reported never wearing and 32% (± 0.6%) inconsistently wearing a helmet. Only 26% (± 0.5%) of students reported always wearing a bicycle helmet. Helmets were less frequently used among older students and there were also important patterns by sex, geographic location and socioeconomic status. Adjusting for all other demographic characteristics, boys reported 2.02-fold increase (95% CI: 1.61 to 1.90) and new immigrants a 1.35-fold increase (95%CI: 1.00 to1.82) in the relative risk of bicycling-related injury in the past 12 months

  2. Homogeneous rhodium(i)-catalysis in de novo heterocycle syntheses.

    Science.gov (United States)

    Neuhaus, James D; Willis, Michael C

    2016-06-14

    Recent research has led to the development of mild, efficient and selective catalytic systems based on Rh(i) complexes. This review summarises the applications of these catalysts to the synthesis of heterocycles from simple building blocks. Included herein are approaches based on cycloisomerisation, cycloaddition, hydroacylation and hydroarylation reactions, as well as various tandem and domino procedures and carbonylation processes.

  3. STRESS ANALYSIS OF BICYCLE FRAME

    Directory of Open Access Journals (Sweden)

    Mr.M.V.Pazare

    2014-06-01

    Full Text Available This paper deals with the stress analysis of bicycle frame by using Finite Element Method. The analysis is carried out in Ansys, The F.E.A. results are compared with theoretical results. In theoretical analysis the frame is treated as truss like structure and the stresses in various members of frame like top tube, down tube, seat tube, chain stay and seat stay are determined, considering various condition like, static start up, steady state paddling, vertical impact, horizontal impact, rear wheel braking. Also Finite Element Analysis is done considering the above conditions. From the analysis it is found that there is a good agreement between analytical and F.E.A. results. Result of all the cases reveals that maximum stress is found in top tube of the bicycle frame as compared to other frame members and is equal to 24.84 MPa which is less than yield strength in tension (i.e.Syt = 290 MPa for the material (aluminum T 6061 selected.

  4. Mobile cockpit system for enhanced electric bicycle use

    OpenAIRE

    João C. Ferreira; Monteiro, Vítor Duarte Fernandes; Afonso, José A.; Afonso, João L.

    2015-01-01

    This paper presents the project of a Mobile Cockpit System (MCS) for smartphones, which provides assistance to Electric Bicycle (EB) cyclists in Smart Cities’ environment. The presented system introduces a mobile application (MCS App) with the goal to provide useful personalized information to the cyclist related with the EB’s use, including EB range prediction considering the intended path, management of the cycling effort performed by the cyclist, handling of the battery charging process an...

  5. Electric bicycles in The Netherlands: Current developments and future possibilities

    NARCIS (Netherlands)

    Rooijen, T. van

    2010-01-01

    Developments with electric bicycles in the Netherlands are progressing rapidly. The number of electric bicycles sold is rises every year. Cycling is a very popular mode of transport in The Netherlands. In 2008 more than one million bicycles were sold. At the moment one out of ten bicycles sold is al

  6. Ruthenium(II) complexes bearing pyridine-functionalized N-heterocyclic carbene ligands: Synthesis, structure and catalytic application over amide synthesis

    Indian Academy of Sciences (India)

    MUTHUKUMARAN NIRMALA; PERIASAMY VISWANATHAMURTHI

    2016-11-01

    A series of four imidazolium salts was synthesized by the reaction of 2-bromopyridine with 1- substituted imidazoles. These imidazolium salts (1a–d) were successfully employed as ligand precursors for the syntheses of new ruthenium(II) complexes bearing neutral bidentate ligands of N-heterocyclic carbene and pyridine donor moiety. The NHC-ruthenium(II) complexes (3a–d) were synthesized by reacting the appropriately substituted pyridine-functionalized N-heterocyclic carbenes with Ag₂O forming the NHC–silver bromide in situ followed by transmetalation with [RuHCl(CO)(PPh₃)₃]. The new complexes were characterized by elemental analyses and spectroscopy (IR, UV-Vis, ¹H, ¹³C, ³¹P-NMR) as well as ESI mass spectrometry. Based on the spectral results, an octahedral geometry was assigned for all the complexes. The complexes were shown to be efficient catalysts for the one-pot conversion of various aldehydes to their corresponding primary amides with good to excellent isolated yields using NH₂OH.HCl and NaHCO₃. The effects of solvent, base, temperature, time and catalyst loading were also investigated. A broad range of amides were successfully synthesized with excellent isolated yields using the above optimized protocol. Notably, the complex 3a was found to be a very efficient and versatile catalyst towards amidation of a wide range of aldehydes.

  7. Azomesogens with a heterocyclic moiety

    Indian Academy of Sciences (India)

    Jayrang S Dave; Meera Menon

    2000-06-01

    Azobenzene derivatives were among the first ten liquid crystalline compounds. But there have been no detailed investigations on azomesogens consisting of a heterocyclic moiety. Twelve different azo compounds have been condensed with nicotinic acid to evaluate the effect of variation of terminal group on the monosubstituted pyridine system. The relative thermal stabilities and the variation in the mesomorphic characteristics have also been studied.

  8. Simultaneous optimization of transit network and public bicycle station network

    Institute of Scientific and Technical Information of China (English)

    刘洋; 朱宁; 马寿峰

    2015-01-01

    The traditional manner to design public transportation system is to sequentially design the transit network and public bicycle network. A new public transportation system design problem that simultaneously considers both bus network design and public bicycle network design is proposed. The chemical reaction optimization (CRO) is designed to solve the problem. A shortcoming of CRO is that, when the two-molecule collisions take place, the molecules are randomly picked from the container. Hence, we improve CRO by employing different mating strategies. The computational results confirm the benefits of the mating strategies. Numerical experiments are conducted on the Sioux-Falls network. A comparison with the traditional sequential modeling framework indicates that the proposed approach has a better performance and is more robust. The practical applicability of the approach is proved by employing a real size network.

  9. Survey of options on legalizing bicycling (VB)

    DEFF Research Database (Denmark)

    Zwahlen, Jurg; Sulewski, Sharon; Sacovitch, Stephen;

    1999-01-01

    the opposition against the proposal was.The goal of this project was to identify categories of users that were opposed to bicycling on the Dosseringen of the Østerbro and Nørrebro District lakes in Copenhagen. The identification of the opposition and its strength, rationale and organization was in terms of age......, gender, residency, frequency of use and their utilization of the area (i.e. walking, jogging, bicycling) as compared to the support for bicycling in the area. This was an Interactive Qualifying Project (IQP), that was designed to merge technical and scientific knowledge with society, and stresses...... the importance of this interaction....

  10. A Sociological Analysis of the Relationship between Attitude towards Bicycle and Using Bicycle in Short Trips in Isfahan

    Directory of Open Access Journals (Sweden)

    Siroos Ahmadi

    2013-07-01

    The main goal of this research is to investigate relationship between attitude toward bicycle and using bicycle among the men in Isfahan. Based on the descriptive research findings, mean using bicycle score is low in Iran. This situation is not satisfactory for a metropolis such as Isfahan that has an increasing population and motor vehicles, and also has many difficulties in urban base facilities and must be changed. In addition to mean attitude toward bicycle is high that is an opportunity for urban planners. Inferential findings show that attitude toward bicycle has a significant impact on using bicycle. In other words, increase attitude toward bicycle means an increase in using bicycle for short trips. This research finding theoretically confirm relation between attitude and behavior. Moreover it is compatible with results of the research that show there is significant relationship between attitude toward bicycle and using bicycle. There is an inverse significant relationship between age and using bicycle and with rising age using bicycle is decreased. This research finding shows that urban infrastructure in Isfahan for using bicycle is not available and consequently with rising age, bicycle risk is increased. There is a direct significant relationship between income rate and using bicycle and with increasing income rate, using bicycle is also increased. This research finding is rooted in social prestige bicycle and higher classes prefer to use motor vehicle for transportation instead of bicycle. There is a significant relationship between marital status and using bicycle and single men use bicycle more than married men but there is no significant relationship between education level and using bicycle. This research findings show that with rising education level in spite of rising income, using bicycle is not decreased. And finally there is no significant relationship between employed and unemployed persons in using bicycle. On the basis of the evidences such

  11. Synthesis of Caged Bicyclic Phosphate Derivatives

    Institute of Scientific and Technical Information of China (English)

    FANG Xiao-min; OU Yu-xiang; LUO Rui-bin; WANG Yong; LIAN Dan-jun; LI Xin

    2008-01-01

    Seven caged bicyclic phosphate compounds were synthesized by using 1-oxo-4-hydroxymethy1-2,6,7-trioxa-1-pho-sphabicyclo[2.2.2] octane (PEPA) as starting material. Within them were three PEPA derivatives containing single caged bicyclic phosphate structure(1a,2a,3a), another three PEPA deviratives containing two caged bicyclic phosphate structures(1b,2b,3b) and one devirative(1c) containing three caged bicyclic phosphate structures. Structures of the products were characterized by FTIR, 1H NMR, elemental analysis and TG analysis. The reaction conditions were also discussed. Thermal analysis showed they had high thermal stability and excellent char-forming ability. Besides, these compounds had pentaerythritol bone and flame retardant elements of phosphorus, bromine or nitrogen simultaneously in their molecules, endowed them with good fire retardancy, and made them can be used as intumescent flame retardant.

  12. 36 CFR 1004.30 - Bicycles.

    Science.gov (United States)

    2010-07-01

    ... routes designated for bicycle use; provided, however, that the Board may close any Presidio Trust road or... consistent with the protection of natural, scenic and aesthetic values, safety considerations and...

  13. 36 CFR 4.30 - Bicycles.

    Science.gov (United States)

    2010-07-01

    ... road or parking area to bicycle use pursuant to the criteria and procedures of §§ 1.5 and 1.7 of this... consistent with the protection of a park area's natural, scenic and aesthetic values, safety...

  14. Application of a quantitative structure retention relationship approach for the prediction of the two-dimensional gas chromatography retention times of polycyclic aromatic sulfur heterocycle compounds.

    Science.gov (United States)

    Gieleciak, Rafal; Hager, Darcy; Heshka, Nicole E

    2016-03-11

    Information on the sulfur classes present in petroleum is a key factor in determining the value of refined products and processing behavior in the refinery. A large part of the sulfur present is included in polycyclic aromatic sulfur heterocycles (PASHs), which in turn are difficult to desulfurize. Furthermore, some PASHs are potentially more mutagenic and carcinogenic than polycyclic aromatic hydrocarbons, PAHs. All of this calls for improved methods for the identification and quantification of individual sulfur species. Recent advances in analytical techniques such as comprehensive two-dimensional gas chromatography (GC×GC) have enabled the identification of many individual sulfur species. However, full identification of individual components, particularly in virgin oil fractions, is still out of reach as standards for numerous compounds are unavailable. In this work, a method for accurately predicting retention times in GC×GC using a QSRR (quantitative structure retention relationship) method was very helpful for the identification of individual sulfur compounds. Retention times for 89 saturated, aromatic, and polyaromatic sulfur-containing heterocyclic compounds were determined using two-dimensional gas chromatography. These retention data were correlated with molecular descriptors generated with CODESSA software. Two independent QSRR relationships were derived for the primary as well as the secondary retention characteristics. The predictive ability of the relationships was tested by using both independent sets of compounds and a cross-validation technique. When the corresponding chemical standards are unavailable, the equations developed for predicting retention times can be used to identify unknown chromatographic peaks by matching their retention times with those of sulfur compounds of known molecular structure.

  15. Electric motor assisted bicycle as an aerobic exercise machine.

    Science.gov (United States)

    Nagata, T; Okada, S; Makikawa, M

    2012-01-01

    The goal of this study is to maintain a continuous level of exercise intensity around the aerobic threshold (AT) during riding on an electric motor assisted bicycle using a new control system of electrical motor assistance which uses the efficient pedaling rate of popular bicycles. Five male subjects participated in the experiment, and the oxygen uptake was measured during cycling exercise using this new pedaling rate control system of electrical motor assistance, which could maintain the pedaling rate within a specific range, similar to that in previous type of electrically assisted bicycles. Results showed that this new pedaling rate control system at 65 rpm ensured continuous aerobic exercise intensity around the AT in two subjects, and this intensity level was higher than that observed in previous type. However, certain subjects were unable to maintain the expected exercise intensity because of their particular cycling preferences such as the pedaling rate. It is necessary to adjust the specific pedaling rate range of the electrical motor assist control according to the preferred pedaling rate, so that this system becomes applicable to anyone who want continuous aerobic exercise.

  16. Electric motor assisted bicycle as an aerobic exercise machine.

    Science.gov (United States)

    Nagata, T; Okada, S; Makikawa, M

    2012-01-01

    The goal of this study is to maintain a continuous level of exercise intensity around the aerobic threshold (AT) during riding on an electric motor assisted bicycle using a new control system of electrical motor assistance which uses the efficient pedaling rate of popular bicycles. Five male subjects participated in the experiment, and the oxygen uptake was measured during cycling exercise using this new pedaling rate control system of electrical motor assistance, which could maintain the pedaling rate within a specific range, similar to that in previous type of electrically assisted bicycles. Results showed that this new pedaling rate control system at 65 rpm ensured continuous aerobic exercise intensity around the AT in two subjects, and this intensity level was higher than that observed in previous type. However, certain subjects were unable to maintain the expected exercise intensity because of their particular cycling preferences such as the pedaling rate. It is necessary to adjust the specific pedaling rate range of the electrical motor assist control according to the preferred pedaling rate, so that this system becomes applicable to anyone who want continuous aerobic exercise. PMID:23366293

  17. Modern advances in heterocyclic chemistry in drug discovery.

    Science.gov (United States)

    Taylor, Alexandria P; Robinson, Ralph P; Fobian, Yvette M; Blakemore, David C; Jones, Lyn H; Fadeyi, Olugbeminiyi

    2016-07-12

    New advances in synthetic methodologies that allow rapid access to a wide variety of functionalized heterocyclic compounds are of critical importance to the medicinal chemist as it provides the ability to expand the available drug-like chemical space and drive more efficient delivery of drug discovery programs. Furthermore, the development of robust synthetic routes that can readily generate bulk quantities of a desired compound help to accelerate the drug development process. While established synthetic methodologies are commonly utilized during the course of a drug discovery program, the development of innovative heterocyclic syntheses that allow for different bond forming strategies are having a significant impact in the pharmaceutical industry. This review will focus on recent applications of new methodologies in C-H activation, photoredox chemistry, borrowing hydrogen catalysis, multicomponent reactions, regio- and stereoselective syntheses, as well as other new, innovative general syntheses for the formation and functionalization of heterocycles that have helped drive project delivery. Additionally, the importance and value of collaborations between industry and academia in shaping the development of innovative synthetic approaches to functionalized heterocycles that are of greatest interest to the pharmaceutical industry will be highlighted. PMID:27282396

  18. Heterociclos 1,2,3-triazólicos: histórico, métodos de preparação, aplicações e atividades farmacológicas 1,2,3-triazolic heterocycles: history, preparations, applications and pharmacological activities

    Directory of Open Access Journals (Sweden)

    Júlio O. F. Melo

    2006-06-01

    Full Text Available The 1,2,3-triazole, known since the end of 19th century, is a very widely used heterocyclic system present in many synthetic substances and commercial pharmaceutical compounds. In fact, 1,2,3-triazoles show several applications in many areas especially as medicines against many diseases like cancer, AIDS, Parkinson and Alzheimer. Nowadays there is a large variety of known methods to obtain these heterocyclic compounds comprising mainly three synthetic routes. Nevertheless, there is no article that gives an objective overview of the synthetic methods for obtaining these kinds of azoheterocycles. This paper presents a brief history of this class of compounds, and a synthetic discussion concerning the main synthetic methods for its preparation, such as cyclization through hydrazones, concerted cycloadditon [2+3] and pseudopericyclic cyclization - and some others of restricted application, but also important. Finally, this paper also provides a brief overview on pharmacological applications of some 1,2,3-triazoles.

  19. Heterocyclic compounds as carbonic anhydrase inhibitor.

    Science.gov (United States)

    Husain, Asif; Madhesia, Diwakar

    2012-12-01

    The carbonic anhydrases (CAs, EC 4.2.1.1) constitute interesting targets for the design of pharmacological agents useful in the treatment or prevention of a variety of disorders such as, glaucoma, acid-base disequilibria, epilepsy, and other neuromuscular diseases, altitude sickness, edema, and obesity. A quite new and unexpected application of the CA inhibitors (CAIs) is with regard to their potential use in the management (imaging and treatment) of hypoxic tumors. A series of sulfonamides, including some clinically used derivatives like acetazolamide, methazolamide, ethoxzolamide, dichlorophenamide, dorzolamide, brinzolamide, benzolamide, and sulpiride, or indisulam, a compound in clinical development as antitumor drug, as well as the sulfamate antiepileptic drug topiramate have been reported to inhibit various human carbonic anhydrase isozyme. Various heterocyclic sulfonamides have been reported in this review with their potency to inhibit different carbonic anhydrases isozymes. PMID:21981003

  20. Public Bicycle Share Programs and Head Injuries

    Science.gov (United States)

    Pless, Barry; Moore, Lynne; Nathens, Avery B.; Hunte, Garth; Rivara, Frederick P.

    2014-01-01

    Objectives. We evaluated the effect of North American public bicycle share programs (PBSPs), which typically do not offer helmets with rentals, on the occurrence of bicycle-related head injuries. Methods. We analyzed trauma center data for bicycle-related injuries from 5 cities with PBSPs and 5 comparison cities. We used logistic regression models to compare the odds that admission for a bicycle-related injury would involve a head injury 24 months before PBSP implementation and 12 months afterward. Results. In PBSP cities, the proportion of head injuries among bicycle-related injuries increased from 42.3% before PBSP implementation to 50.1% after (P < .01). This proportion in comparison cities remained similar before (38.2%) and after (35.9%) implementation (P = .23). Odds ratios for head injury were 1.30 (95% confidence interval = 1.13, 1.67) in PBSP cities and 0.94 (95% confidence interval = 0.79, 1.11) in control cities (adjusted for age and city) when we compared the period after implementation to the period before. Conclusions. Results suggest that steps should be taken to make helmets available with PBSPs. Helmet availability should be incorporated into PBSP planning and funding, not considered an afterthought following implementation. PMID:24922150

  1. THE POLYMERIZATION OF AROMATIC AND HETEROCYCLIC DINITRILES

    Institute of Scientific and Technical Information of China (English)

    HUANG Zhitang

    1988-01-01

    This review is a concise survey about the works in our laboratory on the polymerization of aromatic and heterocyclic dinitriles, including the polymerization kinetics and mechanism, synthesis of heterocyclic dinitriles, the structure of polymers, and the correlation between the structures of dinitriles and polymerization rates and thermal performances of polymers.

  2. Bicycling to school improves the cardiometabolic risk factor profile

    DEFF Research Database (Denmark)

    Ostergaard, Lars; Børrestad, Line A B; Tarp, Jakob;

    2012-01-01

    To investigate whether bicycling to school improves cardiometabolic risk factor profile and cardiorespiratory fitness among children.......To investigate whether bicycling to school improves cardiometabolic risk factor profile and cardiorespiratory fitness among children....

  3. Aromatic and heterocyclic perfluoroalkyl sulfides. Methods of preparation

    Directory of Open Access Journals (Sweden)

    Vladimir N. Boiko

    2010-08-01

    Full Text Available This review covers all of the common methods for the syntheses of aromatic and heterocyclic perfluoroalkyl sulfides, a class of compounds which is finding increasing application as starting materials for the preparation of agrochemicals, pharmaceutical products and, more generally, fine chemicals. A systematic approach is taken depending on the mode of incorporation of the SRF groups and also on the type of reagents used.

  4. Electronic bond tuning with heterocyclic carbenes

    KAUST Repository

    Falivene, Laura

    2013-01-01

    We discuss the impact of the nature of the heterocyclic carbene ring, when used as a complex forming ligand, on the relative stability of key intermediates in three typical Ru, Pd and Au promoted reactions. Results show that P-heterocyclic carbenes have a propensity to increase the bonding of the labile ligand and of the substrate in Ru-promoted olefin metathesis, whereas negligible impact is expected on the stability of the ruthenacycle intermediate. In the case of Pd cross-coupling reactions, dissociation of a P-heterocyclic carbene is easier than dissociation of the N-heterocyclic analogue. In the case of the Au-OH synthon, the Au-OH bond is weakened with the P-heterocyclic carbene ligands. A detailed energy decomposition analysis is performed to rationalize these results. © 2013 The Royal Society of Chemistry.

  5. Bicycle helmet promotion programs--Canada, Australia, and United States.

    Science.gov (United States)

    1993-03-26

    The use of bicycle helmets substantially reduces the risk for serious head injuries during bicycle-related crashes. Despite this benefit, epidemiologic data indicate a worldwide low prevalence of helmet use. Strategies to increase the use of bicycle helmets in the United States and other countries include subsidies, legislation, and education. This report summarizes information regarding three strategies to increase bicycle helmet use and the impact of implementing these approaches in Canada (helmet subsidies), Australia (legislation), and the United States (education). PMID:8446097

  6. On the stability of a bicycle on rollers

    Energy Technology Data Exchange (ETDEWEB)

    Cleary, Patricia A [Department of Geosciences, University of Wisconsin-Parkside, Kenosha, WI 53141 (United States); Mohazzabi, Pirooz, E-mail: pirooz.mohazzabi@uwp.edu [Department of Physics, University of Wisconsin-Parkside, Kenosha, WI 53141 (United States)

    2011-09-15

    Riding a bicycle on the newest form of indoor training, rollers, presents a unique experiment on bicycle stability. The stability factors eliminated by riding on rollers are discussed in terms of refined handling and control of the centre of mass on a bicycle. This paper is intended for undergraduate physics majors as well as any other general readership interested in the dynamics of bicycle stability.

  7. Beijing Bicycle - Stories from a Transformative Space

    DEFF Research Database (Denmark)

    Bagger-Petersen, Mai Corlin

    2012-01-01

    ’s Beijing Bicycle can be understood as the result of stories-so-far, as the cinematic representation of the globalized ”space” within the setting of the national. Beijing Bicycle is a production of space as well as a space of production, since it tells a new story in the trajectory of stories......Ideas, words, images and stories travel from west to east – and from east to west. Stories are chosen and retold in different settings and images are reproduced and appropriated into new contexts – and in new times. Cinema, in this case the mainland Chinese, becomes both a space of production...... and a production of space that reveals how transnational and translocal mechanisms affect the cinematic language, transforming the images and stories chosen for the cinematic representation. Wang Xiaoshuai’s Beijing Bicycle (Shiqi Sui de Danche) (2001) is a result of transnational currents weaving the carpet...

  8. N-alkylphenothiazines - synthesis, structure and application as ligands in metal complexes

    Directory of Open Access Journals (Sweden)

    Krstić Milena

    2016-01-01

    Full Text Available Phenothiazines are a large group of heterocyclic, aromatic molecules with nitrogen and sulphur between two benzene rings. Their derivatives, N-alkylphenothiazines have supstitutient on heterocyclic nitrogen atom which gives them different properties. Also, a series of these molecules have substitution on carbon atom at place 2 of phenothiazine benzene ring. Alkylphenothiazines contain aminoalkyl substituent and their alkyl, acyl and sulphonil derivatives, as well as monocyclic and bicyclic heterocycles attached at thiazine nitrogen atom or directly linked to benzene ring. The N-alkylphenothiazines have been known as antipsychotic drugs, but they also possess antibacterial, antifungal, anticancer activity, and ability to react with macromolecules and to coordinate to the metals. Metal complexes with N-alkylphenothiazines are biological active compounds with different antimicrobial activities and cytotoxic effect against tumor cell lines. Their large field of application of N-alkylphenothiazines is very attractive in terms of synthesis of new related derivatives, metal complexes, studying their properties and applications. This article presents a review of the literature and a contemporary view at N-alkylphenothiazines - their synthesis and application, as well as their metal complexes which have promising biological effects. [Projekat Ministarstva nauke Republike Srbije, br. 172014

  9. 稠杂环化合物在红色磷光铱配合物中的应用%Application of Fused-Heterocyclic Compounds in Red Phosphorescent Iridium(Ⅲ) Complexes

    Institute of Scientific and Technical Information of China (English)

    王玲霞; 梅群波; 颜芳; 田波; 翁洁娜; 张彬; 黄维

    2012-01-01

    Organic light-emitting diodes (OLEDs) have attracted considerable attention during the last decade because of the potential advantages associated with their usage in full-color displays. Electroluminescent phosphorescent materials have also enjoyed similar levels of attention because of their excellent luminescent properties. The three primary colors, blue, green, and red, are essential for the practical application of phosphorescent complexes in flat-panel displays. Relative to the efficient green phosphorescent materials, red phosphorescent materials suffer many problems, including poor color purity, low efficiency, and low luminance, and the design of appropriate red colored materials therefore represents a significant challenge. Fused-heterocyclic compounds have been widely used in red phosphorescent iridium(Ⅲ) complexes because of their high quantum efficiency, color adjustability, and balanced charge injection and migration. This review summarizes the development and application of fused-heterocyclic compounds in recent years in small molecule, dendrimer and polymeric red phosphorescent iridium(Ⅲ) complexes. The influence of the molecular structures of iridium(Ⅲ) complexes on the optical and electrical properties and device performances has also been described. Finally, a discussion of the prospect of developing fused-heterocyclic compounds in the red phosphorescent materials has also been provided.%在过去的几十年里,有机发光二极管(OLED)由于潜在的优势,在全彩显示领域引起了高度重视.电致磷光材料因其优异的发光性能,引起了人们广泛关注.对于实际应用的平板显示器,蓝、绿、红三基色是必不可少的.相对于高效的绿光材料,红光磷光材料仍然存在色纯度差、效率低和亮度不足等问题,因此设计合适的红光材料成为具有挑战性的问题.稠杂环化合物因发光量子效率高、发光颜色可调、平衡电荷注入及迁移等优越性能而广泛

  10. On the Stability of a Bicycle on Rollers

    Science.gov (United States)

    Cleary, Patricia A.; Mohazzabi, Pirooz

    2011-01-01

    Riding a bicycle on the newest form of indoor training, rollers, presents a unique experiment on bicycle stability. The stability factors eliminated by riding on rollers are discussed in terms of refined handling and control of the centre of mass on a bicycle. This paper is intended for undergraduate physics majors as well as any other general…

  11. An Analysis of Florida Physical Educators' Knowledge of Bicycle Laws

    Science.gov (United States)

    Connaughton, Daniel P.; Egberts, John B.; Spengler, J. O.; Zhang, James J.; Jin, Liyan

    2012-01-01

    Bicycling among youth is a popular activity, but like all modes of travel it is not without risk. Florida has a particularly high rate of bicycle-related fatalities and injuries. To reduce such risks, the Florida Department of Transportation and Florida Department of Education have developed a youth bicycle safety educational program (Florida…

  12. Successful Swiss solar bicycles in Australia

    International Nuclear Information System (INIS)

    The article takes a look at the Swiss 'Spirit of Bike' team's success in the 'Power Challenge' race across Australia using solar-bicycles based on commercially available models. Apart from the sporting aspects of race, technical details on the cycles and their supply of solar power are given. Also, the history behind the success of the team is presented and the monitoring of man (and woman) and machine during the race is described. The article also discusses the electric bicycles that are commercially available and the potential of these energy-efficient vehicles in Switzerland

  13. Bicyclic semigroups of left I-quotients

    CERN Document Server

    Ghroda, Nassraddin

    2011-01-01

    In this article we study left I-orders in the bicyclic monoid $\\mathcal{B}$. We give necessary and sufficient conditions for a subsemigroup of $\\mathcal{B}$ to be a left I-oreder in $\\mathcal{B}$. We then prove that any left I-order in $\\mathcal{B}$ is straight.

  14. What do we know about bicycle helmets?

    NARCIS (Netherlands)

    Bogerd, C.P. Halldin, P. Houtenbos, M. Otte, D. Rossi, R.M. Walker, L. Willinger, R. & Shinar, D.

    2012-01-01

    Cycling is an excellent sustainable alternative to driving for many journeys. But cyclists have fewer safety options than car-users, with a helmet being the main safety device that is available. However, there are indications that increasing bicycle helmet usage through legislation causes confoundin

  15. 15 CFR 265.22 - Bicycle traffic.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Bicycle traffic. 265.22 Section 265.22... STANDARDS AND TECHNOLOGY, DEPARTMENT OF COMMERCE REGULATIONS GOVERNING TRAFFIC AND CONDUCT REGULATIONS GOVERNING TRAFFIC AND CONDUCT ON THE GROUNDS OF THE NATIONAL INSTITUTE OF STANDARDS &...

  16. Solutions to the Triangular Bicycle Flags Problem

    Science.gov (United States)

    Hartweg, Kim

    2005-01-01

    Students in a fifth-grade general education class and a second-grade gifted class participated in the Triangular Bicycle Flags problem. The results indicated that providing students with geometric experiences at the correct van Hiele level is necessary for helping students move from one level of understanding to the next.

  17. Assessing and Prioritizing bicycle projects in Denmark: the CPP-Model

    DEFF Research Database (Denmark)

    Salling, Kim Bang

    2011-01-01

    billion DKK in the period from 2009-2014. This presentation will mainly focus upon the modelling aspect of the prioritization of different bicycle applications for the funds and the experiences from the latter. Accordingly, the modelling approach is based upon the collaborative work between the Technical...

  18. A universal isocyanide for diverse heterocycle syntheses

    NARCIS (Netherlands)

    Patil, Pravin; Dömling, Alexander; Khoury, Kareem; Herdtweck, Eberhardt

    2014-01-01

    Novel scaffolds are of uttermost importance for the discovery of functional material. Three different heterocyclic scaffolds easily accessible from isocyanoacetaldehyde dimethylacetal 1 by multicomponent reaction (MCR) are described. They can be efficiently synthesized by a Ugi tetrazole multicompon

  19. Traffic conflicts on bicycle paths: a systematic observation of behaviour from video

    NARCIS (Netherlands)

    Horst, A.R.A. van der; Goede, M. de; Hair-Buijssen, S.H.H.M. de; Methorst, R.

    2014-01-01

    In The Netherlands, on bicycle paths, single-bicycle accidents, bicycle-bicycle and bicycle-moped accidents constitute a considerable share of all bicyclist injuries. Over three quarters of all hospitalised bicyclist victims in the Netherlands cannot be directly related to a crash with motorised tra

  20. Synthesis and application of novel heterocyclic dyes based on 11-amino-13H-acenaphtho[1,2-e]pyridazino[3,2-b]quinazolin-13-one

    Directory of Open Access Journals (Sweden)

    RANJAN G. PATEL

    2002-11-01

    Full Text Available A new fused heterocyclic compound, 11-amino-13H-acenaphtho[1,2-e]pyridazino [3,2-b]quinazolin-13-one was synthesized and used to prepare a novel series of heterocyclic mono azo dyes by coupling with various naphthols. All the mono azo dyes were characterized by their melting point, elemental analysis,UV-visible spectrum, infrared spectrum and dyeing performance on nylon and polyester fibres. The percentage dye bath exhaustion on different fibres was found to be reasonably good and acceptable. The dyed fibres show fair to good fastness to light and very good to excellent fastness to washing, rubbing, perspiration and sublimation.

  1. Physiological and cognitive responses when riding an electrically assisted bicycle versus a classical bicycle.

    Science.gov (United States)

    Theurel, J; Theurel, A; Lepers, R

    2012-01-01

    The present study compared the physiological responses and the subsequent cognitive performance when riding an electrically assisted (EB) versus a classical (CB) bicycle. Oxygen uptake, heart rate and leg extensor muscles electromyographic (EMG) activity were recorded in 10 subjects during a 30-min intermittent cycling exercise performed with EB versus CB. Cognitive performance was evaluated by a mail sorting test, performed at rest and after each cycling session. Averaged oxygen uptake and heat rate were significantly (P cycling than during CB cycling. The EMG activities of the vastus lateralis, rectus femoris and gastrocnemius medialis muscles were significantly (P cycling than during EB cycling. The time to complete the mail sorting test was significantly (P cycling than after CB cycling. Because EB cycling reduced muscle strains and physiological stress, it might offer benefits for those using bicycles in their work, such as postal workers and police officers. STATEMENT OF RELEVANCE: This study compared physiological and cognitive responses when riding an electrically assisted versus a classical bicycle. The results showed that the electrically assisted bicycle led to reduced muscle strains and physiological stress and, therefore, might offer benefits for those using bicycles in their work, such as postal workers and police officers. PMID:22506555

  2. Fatal falls from bicycles: a case report.

    Science.gov (United States)

    Venara, A; Mauillon, D; Gaudin, A; Rouge-Maillart, C; Jousset, N

    2013-03-10

    Though rare occurrences, fatal falls from bicycles are generally linked to the absence of a protective helmet and/or a collision with another vehicle. The case presented here is exceptional due to its circumstances and the consequences of the accident: a fall with no obstacle at a low speed that brought about multiple traumas and the death of a cyclist wearing a protective helmet. Comparing this against a review of cyclist accidentology literature, this case is unique. The increased use of autopsy in terms of forensic accidentology is to be encouraged so as not to misunderstand the possibility of such lesion-based consequences following a simple fall from a bicycle. PMID:23312586

  3. Maximum Estrada Index of Bicyclic Graphs

    CERN Document Server

    Wang, Long; Wang, Yi

    2012-01-01

    Let $G$ be a simple graph of order $n$, let $\\lambda_1(G),\\lambda_2(G),...,\\lambda_n(G)$ be the eigenvalues of the adjacency matrix of $G$. The Esrada index of $G$ is defined as $EE(G)=\\sum_{i=1}^{n}e^{\\lambda_i(G)}$. In this paper we determine the unique graph with maximum Estrada index among bicyclic graphs with fixed order.

  4. Applying riding-posture optimization on bicycle frame design.

    Science.gov (United States)

    Hsiao, Shih-Wen; Chen, Rong-Qi; Leng, Wan-Lee

    2015-11-01

    Customization design is a trend for developing a bicycle in recent years. Thus, the comfort of riding a bike is an important factor that should be paid much attention to while developing a bicycle. From the viewpoint of ergonomics, the concept of "fitting object to the human body" is designed into the bicycle frame in this study. Firstly, the important feature points of riding posture were automatically detected by the image processing method. In the measurement process, the best riding posture was identified experimentally, thus the positions of feature points and joint angles of human body were obtained. Afterwards, according to the measurement data, three key points: the handlebar, the saddle and the crank center, were identified and applied to the frame design of various bicycle types. Lastly, this study further proposed a frame size table for common bicycle types, which is helpful for the designer to design a bicycle. PMID:26154206

  5. Psychological Delaying Model of Bicycle Passing Events on Physically Separated Bicycle Roadways in China*

    Science.gov (United States)

    Zhao, De; Wang, Wei; Li, Zhibin; Shan, Xiaonian; Sun, Xin

    Bicycle facilities are quite common in China but there are not enough quantitative methods to evaluate the Level of Service (LOS) of bicycle roadways. The number of passing events, which considers the interactions between bicyclists, has been proved to be a proper indicator for evaluating bicycle LOS under the special traffic and roadway conditions in China. The primary objective of this study is to propose a model considering the delay effects of passing events and rider's overtaking motivation. Field data was collected on South Zhongshan Road and Huaihai Road in Nanjing city of China with 639 bicyclists investigated. Then a new mathematical model was built to evaluate those effects through probability and regression analyses. It was found that the delay effect of passing events and rider's overtaking motivation are significant influencing factors which cannot be omitted. Correlation test shows the fitted relationship is greater between the model prediction and field data comparing with the previous model.

  6. Bicycling and walking are associated with different cortical oscillatory dynamics

    Directory of Open Access Journals (Sweden)

    Lena eStorzer

    2016-02-01

    Full Text Available Although bicycling and walking involve similar complex coordinated movements, surprisingly Parkinson’s patients with freezing of gait typically remain able to bicycle despite severe difficulties walking. This observation suggests functional differences in the motor networks subserving bicycling and walking. However, a direct comparison of brain activity related to bicycling and walking has never been performed, neither in healthy participants nor in patients. Such a comparison could potentially help elucidating the cortical involvement in motor control and the mechanisms through which bicycling ability may be preserved in patients with freezing of gait. The aim of this study was to contrast the cortical oscillatory dynamics involved in bicycling and walking in healthy participants.To this end, EEG and EMG data of 14 healthy participants were analyzed, who cycled on a stationary bicycle at a slow cadence of 40 revolutions per minute (rpm and walked at 40 strides per minute (spm, respectively.Relative to walking, bicycling was associated with a stronger power decrease in the high beta band (23-35 Hz during movement initiation and execution, followed by a stronger beta power increase after movement termination. Walking, on the other hand, was characterized by a stronger and persisting alpha power (8-12 Hz decrease. Both bicycling and walking exhibited movement cycle-dependent power modulation in the 24-40 Hz range that was correlated with EMG activity. This modulation was significantly stronger in walking.The present findings reveal differential cortical oscillatory dynamics in motor control for two types of complex coordinated motor behavior, i.e., bicycling and walking. Bicycling was associated with a stronger sustained cortical activation as indicated by the stronger high beta power decrease during movement execution and less cortical motor control within the movement cycle. We speculate this to be due to the more continuous nature of

  7. Technical analysis and market study of electric bicycles

    OpenAIRE

    Matasyan, Artur

    2015-01-01

    This thesis project was done in collaboration with a Prismattery LLC, which is based in Tallinn, Estonia and is interested in entering the market of electric bicycles. For that reason in this report a detailed study concerning the market of electrical bicycles, its current situation and trends were performed and a promising target market was indicated. The market study showed that although in different countries the specifications and preferred types of electric bicycles may vary,...

  8. Will a bicycle friendly policy make passenger travel more sustainably?

    OpenAIRE

    Christensen, Linda; Jensen, Thomas Christian

    2009-01-01

    The purpose of this paper is to analyse the possibility to transfer a larger part of the short car trips to walking or bicycling in order to obtain environmental and health benefits. The project contains a logistic choice model used to explain which circumstances are particularly important for choosing walking and bicycling, and how very different instruments can promote walking and bicycling at the expense of short car trips. Furthermore, the paper describes the most important factors when c...

  9. Potential risk and its influencing factors for separated bicycle paths.

    Science.gov (United States)

    Xu, Cheng; Yang, Ying; Jin, Sheng; Qu, Zhaowei; Hou, Lei

    2016-02-01

    In this paper, we propose two potential risk indicators to define and evaluate the safety of bicycle path at the microscopic level. Field bicycle data were collected from three survey sites under different traffic conditions. These two risk indicators based on speed dispersion were proposed and calculated during each 5-min interval. The risk influences of various widths of bicycle path and traffic conditions were analyzed by using one-way ANOVA. We further proposed a generalized linear model (GLM) for modeling and analyzing the relationships between bicycle risks and v/c ratio and percentages of electric bicycles, male cyclists, young cyclists, and loaded cyclists. The stepwise regression models were applied for determination of coefficients. The results show that the influences of gender and age of cyclists on potential risks are not significant. The risks increase with the width of bicycle path and percentage of electric bicycles, while only for wider bicycle path (4-lane case in this study), the risks are associated with whether or not cyclists are loaded. The findings could contribute for analysis and evaluation of the safety for bicycle path. PMID:26647016

  10. Potential risk and its influencing factors for separated bicycle paths.

    Science.gov (United States)

    Xu, Cheng; Yang, Ying; Jin, Sheng; Qu, Zhaowei; Hou, Lei

    2016-02-01

    In this paper, we propose two potential risk indicators to define and evaluate the safety of bicycle path at the microscopic level. Field bicycle data were collected from three survey sites under different traffic conditions. These two risk indicators based on speed dispersion were proposed and calculated during each 5-min interval. The risk influences of various widths of bicycle path and traffic conditions were analyzed by using one-way ANOVA. We further proposed a generalized linear model (GLM) for modeling and analyzing the relationships between bicycle risks and v/c ratio and percentages of electric bicycles, male cyclists, young cyclists, and loaded cyclists. The stepwise regression models were applied for determination of coefficients. The results show that the influences of gender and age of cyclists on potential risks are not significant. The risks increase with the width of bicycle path and percentage of electric bicycles, while only for wider bicycle path (4-lane case in this study), the risks are associated with whether or not cyclists are loaded. The findings could contribute for analysis and evaluation of the safety for bicycle path.

  11. Use of automated video analysis for the evaluation of bicycle movement and interaction

    Science.gov (United States)

    Twaddle, Heather; Schendzielorz, Tobias; Fakler, Oliver; Amini, Sasan

    2014-03-01

    With the purpose of developing valid models of microscopic bicycle behavior, a large quantity of video data is collected at three busy urban intersections in Munich, Germany. Due to the volume of data, the manual processing of this data is infeasible and an automated or semi-automated analysis method must be implemented. An open source software, "Traffic Intelligence", is used and extended to analyze the collected video data with regard to research questions concerning the tactical behavior of bicyclists. In a first step, the feature detection parameters, the tracking parameters and the object grouping parameters are calibrated, making it possible to accurately track and group the objects at intersections used by large volumes of motor vehicles, bicycles and pedestrians. The resulting parameters for the three intersections are presented. A methodology for the classification of road users as cars, bicycles or pedestrians is presented and evaluated. This is achieved by making hypotheses about which features belong to cars, or bicycles and pedestrians, and using grouping parameters specified for that road user group to cluster the features into objects. These objects are then classified based on their dynamic characteristics. A classification structure for the maneuvers of different road users is presented and future applications are discussed.

  12. Heterocyclic Anions of Astrobiological Interest

    Science.gov (United States)

    Cole, Callie A.; Demarais, Nicholas J.; Yang, Zhibo; Snow, Theodore P.; Bierbaum, Veronica M.

    2013-12-01

    As more complex organic molecules are detected in the interstellar medium, the importance of heterocyclic molecules to astrobiology and the origin of life has become evident. 2-Aminothiazole and 2-aminooxazole have recently been suggested as important nucleotide precursors, highlighting azoles as potential prebiotic molecules. This study explores the gas-phase chemistry of three deprotonated azoles: oxazole, thiazole, and isothiazole. For the first time, their gas-phase acidities are experimentally determined with bracketing and H/D exchange techniques, and their reactivity is characterized with several detected interstellar neutral molecules (N2O, O2, CO, OCS, CO2, and SO2) and other reactive species (CS2, CH3Cl, (CH3)3CCl, and (CH3)3CBr). Rate constants and branching fractions for these reactions are experimentally measured using a modified commercial ion trap mass spectrometer whose kinetic data are in good accord with those of a flowing afterglow apparatus reported here. Last, we have examined the fragmentation patterns of these deprotonated azoles to elucidate their destruction mechanisms in high-energy environments. All experimental data are supported and complemented by electronic structure calculations at the B3LYP/6-311++G(d,p) and MP2(full)/aug-cc-pVDZ levels of theory.

  13. Heterocyclic anions of astrobiological interest

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Callie A.; Demarais, Nicholas J.; Bierbaum, Veronica M. [Department of Chemistry and Biochemistry, 215 UCB, University of Colorado, Boulder, CO 80309 (United States); Yang, Zhibo [Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019 (United States); Snow, Theodore P., E-mail: Callie.Cole@colorado.edu, E-mail: Nicholas.Demarais@colorado.edu, E-mail: Veronica.Bierbaum@colorado.edu, E-mail: Zhibo.Yang@ou.edu, E-mail: Theodore.Snow@colorado.edu [Department of Astrophysical and Planetary Sciences, 391 UCB, University of Colorado, Boulder, CO 80309 (United States)

    2013-12-20

    As more complex organic molecules are detected in the interstellar medium, the importance of heterocyclic molecules to astrobiology and the origin of life has become evident. 2-Aminothiazole and 2-aminooxazole have recently been suggested as important nucleotide precursors, highlighting azoles as potential prebiotic molecules. This study explores the gas-phase chemistry of three deprotonated azoles: oxazole, thiazole, and isothiazole. For the first time, their gas-phase acidities are experimentally determined with bracketing and H/D exchange techniques, and their reactivity is characterized with several detected interstellar neutral molecules (N{sub 2}O, O{sub 2}, CO, OCS, CO{sub 2}, and SO{sub 2}) and other reactive species (CS{sub 2}, CH{sub 3}Cl, (CH{sub 3}){sub 3}CCl, and (CH{sub 3}){sub 3}CBr). Rate constants and branching fractions for these reactions are experimentally measured using a modified commercial ion trap mass spectrometer whose kinetic data are in good accord with those of a flowing afterglow apparatus reported here. Last, we have examined the fragmentation patterns of these deprotonated azoles to elucidate their destruction mechanisms in high-energy environments. All experimental data are supported and complemented by electronic structure calculations at the B3LYP/6-311++G(d,p) and MP2(full)/aug-cc-pVDZ levels of theory.

  14. Heterocyclic anions of astrobiological interest

    International Nuclear Information System (INIS)

    As more complex organic molecules are detected in the interstellar medium, the importance of heterocyclic molecules to astrobiology and the origin of life has become evident. 2-Aminothiazole and 2-aminooxazole have recently been suggested as important nucleotide precursors, highlighting azoles as potential prebiotic molecules. This study explores the gas-phase chemistry of three deprotonated azoles: oxazole, thiazole, and isothiazole. For the first time, their gas-phase acidities are experimentally determined with bracketing and H/D exchange techniques, and their reactivity is characterized with several detected interstellar neutral molecules (N2O, O2, CO, OCS, CO2, and SO2) and other reactive species (CS2, CH3Cl, (CH3)3CCl, and (CH3)3CBr). Rate constants and branching fractions for these reactions are experimentally measured using a modified commercial ion trap mass spectrometer whose kinetic data are in good accord with those of a flowing afterglow apparatus reported here. Last, we have examined the fragmentation patterns of these deprotonated azoles to elucidate their destruction mechanisms in high-energy environments. All experimental data are supported and complemented by electronic structure calculations at the B3LYP/6-311++G(d,p) and MP2(full)/aug-cc-pVDZ levels of theory.

  15. The relationship between public and private bicycle use: the case of Seville

    OpenAIRE

    José I. Castillo-Manzano; Castro-Nuño, Mercedes; Lopez-Valpuesta, Lourdes

    2015-01-01

    Despite the success achieved by Public Bicycle Sharing Systems (PBSS) across the world, several researchers provide evidence on their limitations and constraints in a medium-long term, and bicycle ownership may be considered as a complementary tool to promote a 'bicycle-culture'. This paper aims to cover the gap about the interaction between both systems (public bicycle / private bicycle) and which are the key aspects to explain the bicycle-buying decision. After a fieldwork based on surveys ...

  16. A New Pathway to Synthesize Cyclomercurated Ferrocenylimines Containing Heterocyclic Ring

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The cyclomercurated ferrocenylimines containing heterocyclic ring were prepared by the condensation of cyclomercuration of acylferrocene with the appropriate heterocyclic amine. This procedure provides an efficient method for the synthesis of cyclomerucurated ferroceny- limines containing heterocyclic ring which are difficultly synthesized by the conventional method. The reaction mechanism is proposed.

  17. Bicycle Sharing in Developing Countries : A proposal towards sustainable transportation in Brazilian median cities

    OpenAIRE

    Dias Batista, Edgard

    2010-01-01

    Bicycle-sharing programs are a new trend in urban transportation. The main difference of a bicycle-sharing program with a regular bicycle rental is that is possible to get a bicycle in one station and return it in any other station. There are many models of bicycle sharing, each model with its pros and cons. This study analyzes the bicycle-sharing models in order to build a proposal of a bicycle-sharing program suitable for Brazilian median cities. The study begins with an overview of bicycle...

  18. Heptaphyrins: Expanded porphyrins with seven heterocyclic rings

    Indian Academy of Sciences (India)

    Venkataramanarao G Anand; Simi K Pushpan; Sundararaman Venkatraman; Tavarekere K Chandrashekar

    2003-10-01

    Expanded porphyrins containing seven pyrrole/heterocyclic rings linked in a cyclic fashion are termed heptaphyrins. The number of -electrons in heptaphyrins depends on the number of meso carbon bridges used to link the heterocyclic rings, accordingly heptaphyrins with 28-electrons and 30 -electrons are reported to date. Both condensation reactions of the appropriate precursors and acid-catalysed oxidative coupling reactions have been utilized to synthesise the heptaphyrins. The 30 heptaphyrins exhibit rich structural diversity where some of the heterocyclic rings in the macrocycle undergo a 180° ring flipping. An overview of the synthetic methods employed for the synthesis of heptaphyrins, their spectroscopic properties, structural behaviour and aromatic properties are highlighted in this paper.

  19. Bicycle Helmet Laws are Associated with a Lower Fatality Rate from Bicycle-Motor Vehicle Collisions

    Science.gov (United States)

    Meehan, William P.; Lee, Lois K.; Fischer, Christopher M.; Mannix, Rebekah C.

    2013-01-01

    Objective To assess the association between bicycle helmet legislation and bicycle-related deaths sustained by children involved in bicycle-motor vehicle collisions. Study design We conducted a cross sectional study of all bicyclists aged 0-16 years included in the Fatality Analysis Reporting System (FARS) who died between January 1999 and December 2010. We compared fatality rates per age-specific state populations between states with helmet laws and those without helmet laws. We used a clustered Poisson multivariate regression model to adjust for factors previously associated with rates of motor vehicle fatalities: elderly driver licensure laws, legal blood alcohol limit ( 0.08 between states with helmet laws and those without helmet laws. The mean unadjusted rates of fatalities were lower in states with helmet laws (2.0/1,000,000 vs. 2.5/1,000,000; p= 0.03). After adjusting for potential confounding factors, states with mandatory helmet laws continued to be associated with a lower rate of fatalities (adjusted Incidence Rate Ratio 0.84; 95% CI 0.70, 0.98). Conclusions Bicycle helmet safety laws are associated with a lower incidence of fatalities among child bicyclists involved in motor vehicle collisions. PMID:23706604

  20. Development of an analytical method for the simultaneous determination of 15 carcinogenic polycyclic aromatic hydrocarbons and polycyclic aromatic nitrogen heterocyclic compounds. application to diesel particulates.

    Science.gov (United States)

    Sauvain, J J; Vu Duc, T; Huynh, C K

    2001-12-01

    A new method enabling the determination of 15 priority carcinogenic polyaromatic compounds (PAC) proposed by the US National Toxicology Program (NTP) has been developed and applied to diesel exhaust particulates (DEP). The clean-up procedure consists of solid-phase extraction (SPE) and HPLC fractionation on silica phases followed by liquid-liquid extraction and chromatography on a polyvinylbenzene copolymer column. The method gives good recoveries for all PAC studied except dibenzo[a,j]acridine and dibenzo[a,h]pyrene, for which recovery values are below 80%. The use of GC-MS ion trap and its capacity to achieve single-ion storage enhanced the sensitivity of the method, enabling the detection of high-molecular-weight PAH in the low ng g(-1) concentration range. Intermediate polarity GC columns, e.g. BPX-50 or equivalent, enabled better separation, when applied to DEP analysis, than the generally used DB-5 apolar phase. This is observed mainly for separation of isomeric compounds belonging to the benzofluoranthene and dibenzopyrene families. The application of this method to DEP sampled from the exhaust of a diesel engine and in confined locations such as a tunnel has shown that all PAH of the NTP list could be detected, except dibenzo[a,h]pyrene. No dibenzacridine or dibenzocarbazole could be detected in such matrices. The method is sufficiently sensitive to be applicable to environmental exposure measurements in occupational health surveys.

  1. Bicycle Freewheeling with Air Drag as a Physics Experiment

    Science.gov (United States)

    Janssen, Paul; Janssens, Ewald

    2015-01-01

    To familiarize first-year students with the important ingredients of a physics experiment, we offer them a project close to their daily life: measuring the effect of air resistance on a bicycle. Experiments are done with a bicycle freewheeling on a downhill slope. The data are compared with equations of motions corresponding to different models…

  2. Methods to assess the stability of a bicycle rider system

    NARCIS (Netherlands)

    Cooke, A.G.; Bulsink, V.E.; Beusenberg, C.M.; Dubbeldam, R.; Bonnema, G.M.; Poelman, W.A.; Koopman, H.F.J.M.

    2012-01-01

    The SOFIE (Intelligent Assisted Bicycles) project wishes to create performance and design guidelines for mechatronic appliances which improve the stability of electric bicycles, so-called intelligent stability assist devices (IAD). To achieve this goal, a stability hypothesis, an advanced rider/bicy

  3. Modeling of speed distribution for mixed bicycle traffic flow

    Directory of Open Access Journals (Sweden)

    Cheng Xu

    2015-11-01

    Full Text Available Speed is a fundamental measure of traffic performance for highway systems. There were lots of results for the speed characteristics of motorized vehicles. In this article, we studied the speed distribution for mixed bicycle traffic which was ignored in the past. Field speed data were collected from Hangzhou, China, under different survey sites, traffic conditions, and percentages of electric bicycle. The statistics results of field data show that the total mean speed of electric bicycles is 17.09 km/h, 3.63 km/h faster and 27.0% higher than that of regular bicycles. Normal, log-normal, gamma, and Weibull distribution models were used for testing speed data. The results of goodness-of-fit hypothesis tests imply that the log-normal and Weibull model can fit the field data very well. Then, the relationships between mean speed and electric bicycle proportions were proposed using linear regression models, and the mean speed for purely electric bicycles or regular bicycles can be obtained. The findings of this article will provide effective help for the safety and traffic management of mixed bicycle traffic.

  4. Bicycle facilities on road segments and intersections of distributor roads.

    NARCIS (Netherlands)

    2008-01-01

    A sustainably safe road environment requires bicycle facilities that separate motorized traffic from relatively vulnerable road users like cyclists. Research indicates that on distributor roads the road sections with adjoining or separate bicycle tracks are safer than the road sections without any b

  5. On Wiener polarity index of bicyclic networks

    Science.gov (United States)

    Ma, Jing; Shi, Yongtang; Wang, Zhen; Yue, Jun

    2016-01-01

    Complex networks are ubiquitous in biological, physical and social sciences. Network robustness research aims at finding a measure to quantify network robustness. A number of Wiener type indices have recently been incorporated as distance-based descriptors of complex networks. Wiener type indices are known to depend both on the network’s number of nodes and topology. The Wiener polarity index is also related to the cluster coefficient of networks. In this paper, based on some graph transformations, we determine the sharp upper bound of the Wiener polarity index among all bicyclic networks. These bounds help to understand the underlying quantitative graph measures in depth.

  6. Revitalization of Cycling in a Former Bicycle Kingdom: Beijing

    DEFF Research Database (Denmark)

    Zhao, Chunli; Carstensen, Trine Agervig; Olafsson, Anton Stahl;

    are revealed by collection and analysis of historical material and interviews with key stakeholders. The historical material is obtained from libraries, online resources, and reports from professionals including urban designers, transportation engineers, research centres and politicians of the Beijing......This paper scrutinizes and analyses the relevant historical policy documents chronologically - from the 1960s to the present - in order to figure out the potentials of revitalizing the bicycle mode share in Beijing. Firstly, we targeted two top-drawer conflicts of the bicycle use, which are travel......- or commuting distance and motorised vehicle-oriented urban development. Secondly, we analysed how the various related policies resulted in the changing landscape of the bicycle mode share, including increasing in the bicycle mode share, created the conflicts and declined the bicycle mode share. The results...

  7. Safety effects of permanent running lights for bicycles

    DEFF Research Database (Denmark)

    Madsen, Jens Chr. Overgaard; Andersen, T.; Lahrmann, Harry

    2013-01-01

    Making the use of daytime running lights mandatory for motor vehicles is generally documented to have had a positive impact upon traffic safety. Improving traffic safety for bicyclists is a focal point in the road traffic safety work in Denmark. In 2004 and 2005 a controlled experiment including...... 3845 cyclists was carried out in Odense, Denmark in order to examine, if permanent running lights mounted to bicycles would improve traffic safety for cyclists. The permanent running lights were mounted to 1845 bicycles and the accident rate was recorded through 12 months for this treatment group......, including all recorded bicycle accidents with personal injury to the participating cyclist, is 19% lower for cyclists with permanent running lights mounted; indicating that the permanent bicycle running light significantly improves traffic safety for cyclists. The study shows that use of permanent bicycle...

  8. Infiuence of Bicycle Traffic on Capacity of Typical Signalized Intersection

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiaoming; SHAO Chunfu; YUE Hao

    2007-01-01

    Bicycle traffic has a significant effect on the capacity of signalized intersections. This paper divides the influence of bicyclists on vehicular flow into four types with the time durations estimated based on probability, shock wave, and gap acceptance theory. Vehicular saturation flow rate is predicted for various conditions on the basis of the speed-flow curve for the capacity of typical intersections influenced by bicycle traffic.The model overcomes the limitations of the Highway Capacity Manual (HCM, 2000) method for left-turns due to data collection, and takes into account the effect of trapped bicycles on the through vehicular traffic.The numerical results show that the left-turn and through capacities predicted by the model are lower than those of the HCM method. The right-turn capacity is close to that of the HCM method at Iow bicycle volumes and higher than that of the HCM method at high bicycle volumes.

  9. Safe bicycling – Problems and solutions

    Directory of Open Access Journals (Sweden)

    Grecka M.

    2014-01-01

    Full Text Available Herewith a popularity of bicycling, various safety problems of cyclists are researched. Studies are connected with infrastructure, riding culture, choice of cyclist's suit and riding equipment. Overall, 382 respondents (159 cyclists, 119 drivers, 104 pedestrians were involved in the survey. The road participants' mutual communication problems in the traffic and opportunities of solving them were clarified. Most of cyclists wear comfortable daily or sporty clothing with reflective elements, and in their opinion, clothing with light emissive elements must be like daily clothing. The drivers could better notice cyclists, if they wear brightly colored suit with light emissive and reflective elements, but pedestrians – if cyclists use warning sound signals. The opinions of road participants about the placement of light emissive and reflective elements in cyclist's clothing were clarified. The prototype of cycling belt (Fig. 1e has been drawn up with LED stop signals, which are activated by the accelerometer placed in the central back pocket. The results of approbation have shown that the sensor does not provide the proper functioning of signals, due to a high level of riding movements. Using Motion Capture technology and bicycle exercise equipment, the research of oscillation of anthropometric points on the back has been carried out. The accelerometer should be placed between scapulae to design the cycling jacket.

  10. The effect of tyre and rider properties on the stability of a bicycle

    NARCIS (Netherlands)

    Bulsink, V.E.; Doria, A.; Belt, van de D.; Koopman, H.F.J.M.

    2015-01-01

    To work towards an advanced model of the bicycle-rider-environment system, an open-loop bicycle-rider model was developed in the commercial multibody dynamics software ADAMS. The main contribution of this article to bicycle dynamics is the analysis of tyre and rider properties that influence bicycle

  11. Helmet Wearing Among Users of a Public Bicycle-Sharing Program in the District of Columbia and Comparable Riders on Personal Bicycles

    Science.gov (United States)

    Roffenbender, Jason S.; Anderko, Laura

    2012-01-01

    Bicycle-sharing programs are increasingly popular and have the potential to increase physical activity and decrease air pollution, but anecdotal evidence suggests helmet use is lower among users of bicycle-sharing programs than cyclists on private bicycles. We conducted a cross-sectional study to assess helmet use among users of a bicycle-sharing program in Washington, DC. Helmet use was significantly lower among cyclists on shared bicycles than private bicycles, highlighting a need for targeted helmet promotion activities. PMID:22698021

  12. Improving bicycle safety: The role of paediatricians and family physicians.

    Science.gov (United States)

    Leblanc, John C; Huybers, Sherry

    2004-05-01

    Cycling is a complex activity requiring motor, sensory and cognitive skills that develop at different rates from childhood to adolescence. While children can successfully ride a two-wheeled bicycle at age five or six, judgment of road hazards are poor at that age and matures slowly until adult-like judgment is reached in early adolescence. Safe cycling depends on the care, skills and judgment of cyclists and motorists; roadway design that promotes safe coexistence of bicycles and motor vehicles; and the use of safety devices, including bicycle helmets, lights and reflective tape. Whereas, research into optimal roadway design and educational programs for drivers to improve road safety has yielded contradictory results, the benefits of bicycle helmet use and programs to enhance their use have been clearly shown. This paper has the following objectives for paediatricians and family physicians: To understand the relationship between bicycle safety and children's motor and cognitive skills.To understand the effectiveness and limitations of strategies to improve bicycle safety.To describe activities to promote bicycle safety that physicians can undertake in clinical settings and in the community. PMID:19657515

  13. The frequency of single-bicycle crashes (SBCs) in countries with varying bicycle mode shares

    DEFF Research Database (Denmark)

    Schepers, Paul; Agerholm, Niels; Amoros, Emmanuelle;

    In  order  to  encourage  cycling,  we  need  to  reduce  the  hazards  that  cyclists  face. Single-bicycle crashes or ‘bicycle-only crashes’ are falls and obstacle collisions in which only one cyclist is involved. Between 60 and 95% of cyclists admitted to hospital or treated at an emergency...... department are victims of single-bicycle crashes. As proportion of the total number of traffic casualties  the  share  exceeds  20%  in  most  countries  with  medium  to  high  levels  of cycling.  This paper  discusses  the  prevalence  of  the  problem  and  describes  measures  that  may  both reduce...... the risks and make cycling a more attractive transport choice at the same time....

  14. Symbolic derivation of bicycle kinematics with toroidal wheels

    Directory of Open Access Journals (Sweden)

    Wang Everett X.

    2015-01-01

    Full Text Available Bicycle kinematics with toroidal wheels is presented in this paper. Using symbolic mathematic tool Maple, we obtain two holonomic and four nonholonomic constraint equations due to front and rear wheels of a bicycle. We show that the two holonomic constraints cannot be expressed in quartic form for bicycle rear body pitch angle unless the minor (crown radius of the torus are the same for both the front and rear wheels. In addition, we show that all the constraints can be written in differential form, from which a constraint matrix is constructed, according to standard procedure for developing dynamics in robotics.

  15. Associations between a walkability index and bicycle use in Denmark

    DEFF Research Database (Denmark)

    Madsen, T.; Christiansen, L.; Nielsen, Thomas Alexander Sick;

    2012-01-01

    /day, and important health benefits can accrue from regular commuting cycling. Studies have shown a positive correlation between walkability attributes of neighborhood environments (street connectivity, and use mix, residential density, retail floor area ratio) and cycling. Results from Australia/Belgium show...... associations between measures of walkability and bicycle use for transport and the present study focuses on exploring whether these findings can be applied to a Danish setting where cycling culture differs and bicycle share is much higher (17% of all trips are by bicycle)...

  16. Associations between bicycling and carotid arterial stiffness in adolescents

    DEFF Research Database (Denmark)

    Ried-Larsen, M; Grøntved, A; Østergaard, Lars;

    2015-01-01

    The aim of the study was to investigate the associations between bicycling and carotid arterial stiffness, independent of objectively measured moderate-and-vigorous physical activity. This cross-sectional study included 375 adolescents (age 15.7 ± 0.4 years) from the Danish site of the European...... modulus [standard beta -0.48 (95% CI -0.91 to -0.06)]. Similar trends were observed when investigating the association between commuter bicycling and carotid arterial stiffness. These associations were not observed in girls. Our observations suggest that increasing bicycling in adolescence may...

  17. The effect of tyre and rider properties on the stability of a bicycle

    OpenAIRE

    Bulsink, V.E.; Doria, A.; Belt, van de, M.; Koopman, H.F.J.M.

    2015-01-01

    To work towards an advanced model of the bicycle-rider-environment system, an open-loop bicycle-rider model was developed in the commercial multibody dynamics software ADAMS. The main contribution of this article to bicycle dynamics is the analysis of tyre and rider properties that influence bicycle stability. A system identification method is used to extract linear stability properties from time domain analysis. The weave and capsize eigenmodes of the bicycle-rider system are analysed. The e...

  18. Bicyclic graphs with maximal revised Szeged index

    CERN Document Server

    Li, Xueliang

    2011-01-01

    The revised Szeged index $Sz^*(G)$ is defined as $Sz^*(G)=\\sum_{e=uv \\in E}(n_u(e)+ n_0(e)/2)(n_v(e)+ n_0(e)/2),$ where $n_u(e)$ and $n_v(e)$ are, respectively, the number of vertices of $G$ lying closer to vertex $u$ than to vertex $v$ and the number of vertices of $G$ lying closer to vertex $v$ than to vertex $u$, and $n_0(e)$ is the number of vertices equidistant to $u$ and $v$. Hansen used the AutoGraphiX and made the following conjecture about the revised Szeged index for a connected bicyclic graph $G$ of order $n \\geq 6$:

  19. Bicycling induced pudendal nerve pressure neuropathy.

    Science.gov (United States)

    Silbert, P L; Dunne, J W; Edis, R H; Stewart-Wynne, E G

    1991-01-01

    Pudendal neuropathies are well recognised as part of more generalised peripheral neuropathies; however, focal abnormalities of the pudendal nerve due to cycling-related injuries have been infrequently reported. We describe two patients who developed pudendal neuropathies secondary to pressure effects on the perineum from racing-bicycle saddles. Both were male competitive athletes, one of whom developed recurrent numbness of the penis and scrotum after prolonged cycling; the other developed numbness of the penis, an altered sensation of ejaculation, with disturbance of micturition and reduced awareness of defecation. Both patients improved with alterations in saddle position and riding techniques. We conclude that pudendal nerve pressure neuropathy can result from prolonged cycling, particularly when using a poor riding technique. PMID:1821826

  20. Bicycle helmet ventilation and comfort angle dependence.

    Science.gov (United States)

    Brühwiler, Paul A; Ducas, Charline; Huber, Roman; Bishop, Phillip A

    2004-09-01

    Five modern bicycle helmets were studied to elucidate some of the variations in ventilation performance, using both a heated manikin headform and human subjects (n = 7). Wind speed and head angle were varied to test their influence on the measured steady-state heat exchange (cooling power) in the skull section of the headform. The cooling power transmitted by the helmets varied from about 60% to over 90% of that of the nude headform, illustrating the range of present manufacturer designs. Angling the head forward by 30 degrees was found to provide better cooling power to the skull (up to 25%) for three of the helmets and almost equal cooling power in the remaining two cases. Comparisons of skull ventilation at these angles with human subjects strongly supported the headform results.

  1. Nitrogen heterocycles as potential monoamine oxidase inhibitors: Synthetic aspects

    Directory of Open Access Journals (Sweden)

    Pravin O. Patil

    2014-12-01

    Full Text Available The present review highlights the synthetic methods of monoamine oxidase inhibitors (MAO belonging to a group of nitrogen heterocycles such as pyrazoline, indole, xanthine, oxadiazole, benzimidazole, pyrrole, quinoxaline, thiazole and other related compounds (1990–2012. Moreover, it emphasizes salient findings related to chemical structures and the bioactivities of these heterocycles as MAO inhibitors. The aim of this review is to find out different methods for the synthesis of nitrogen containing heterocycles and their bioactivity related aspects as MAO inhibitors.

  2. Will a bicycle friendly policy make passenger travel more sustainably?

    DEFF Research Database (Denmark)

    Christensen, Linda; Jensen, Thomas Christian

    The purpose of this paper is to analyse the possibility to transfer a larger part of the short car trips to walking or bicycling in order to obtain environmental and health benefits. The project contains a logistic choice model used to explain which circumstances are particularly important...... for choosing walking and bicycling, and how very different instruments can promote walking and bicycling at the expense of short car trips. Furthermore, the paper describes the most important factors when choosing between bicycling and walking and car driving, respectively, in case of trips of up to 22 km....... Hills and temperature differences appear to be particularly impor-tant, apart from car ownership. Regarding the socio-economy, particularly the number of children is of importance. Furthermore, the paper elucidates the effect of various instruments to promote the transfer of short car trips to walking...

  3. Fluid Mechanics of a High Performance Racing Bicycle Wheel

    Science.gov (United States)

    Mercat, Jean-Pierre; Cretoux, Brieuc; Huat, Francois-Xavier; Nordey, Benoit; Renaud, Maxime; Noca, Flavio

    2013-11-01

    In 2012, MAVIC released the most aerodynamic bicycle wheel on the market, the CXR 80. The french company MAVIC has been a world leader for many decades in the manufacturing of bicycle wheels for competitive events such as the Olympic Games and the Tour de France. Since 2010, MAVIC has been in a research partnership with the University of Applied Sciences in Geneva, Switzerland, for the aerodynamic development of bicycle wheels. While most of the development up to date has been performed in a classical wind tunnel, recent work has been conducted in an unusual setting, a hydrodynamic towing tank, in order to achieve low levels of turbulence and facilitate quantitative flow visualization (PIV). After a short introduction on the aerodynamics of bicycle wheels, preliminary fluid mechanics results based on this novel setup will be presented.

  4. O-Maltosylation of Heterocyclic Ketene Aminals

    Institute of Scientific and Technical Information of China (English)

    XU,Zhan-Hui(徐占辉); HUANG,Zhi-Tang(黄志镗)

    2002-01-01

    The stereoselective synthesis of O-maltosides by reacting benzoyl-substituted heterocyclic ketene aminals 1 or 2 with acetylated maltosyl bromide 3 was investigated. Compounds 1 or 2 reacted with 3 in the presence of mercuric cyanide to give O-maltosides 4 or 5 with E-configuration. While 1 reacted with 3 in the presence of calcium hydride to give O-maltosides 6 with Zconfiguration.

  5. Improving bicycle safety: The role of paediatricians and family physicians

    OpenAIRE

    LeBlanc, John C.; Huybers, Sherry

    2004-01-01

    Cycling is a complex activity requiring motor, sensory and cognitive skills that develop at different rates from childhood to adolescence. While children can successfully ride a two-wheeled bicycle at age five or six, judgment of road hazards are poor at that age and matures slowly until adult-like judgment is reached in early adolescence. Safe cycling depends on the care, skills and judgment of cyclists and motorists; roadway design that promotes safe coexistence of bicycles and motor vehicl...

  6. On the Skill of Balancing While Riding a Bicycle.

    Science.gov (United States)

    Cain, Stephen M; Ashton-Miller, James A; Perkins, Noel C

    2016-01-01

    Humans have ridden bicycles for over 200 years, yet there are no continuous measures of how skill differs between novice and expert. To address this knowledge gap, we measured the dynamics of human bicycle riding in 14 subjects, half of whom were skilled and half were novice. Each subject rode an instrumented bicycle on training rollers at speeds ranging from 1 to 7 m/s. Steer angle and rate, steer torque, bicycle speed, and bicycle roll angle and rate were measured and steering power calculated. A force platform beneath the roller assembly measured the net force and moment that the bicycle, rider and rollers exerted on the floor, enabling calculations of the lateral positions of the system centers of mass and pressure. Balance performance was quantified by cross-correlating the lateral positions of the centers of mass and pressure. The results show that all riders exhibited similar balance performance at the slowest speed. However at higher speeds, the skilled riders achieved superior balance performance by employing more rider lean control (quantified by cross-correlating rider lean angle and bicycle roll angle) and less steer control (quantified by cross-correlating steer rate and bicycle roll rate) than did novice riders. Skilled riders also used smaller steering control input with less variation (measured by average positive steering power and standard deviations of steer angle and rate) and less rider lean angle variation (measured by the standard deviation of the rider lean angle) independent of speed. We conclude that the reduction in balance control input by skilled riders is not due to reduced balance demands but rather to more effective use of lean control to guide the center of mass via center of pressure movements. PMID:26910774

  7. On the Skill of Balancing While Riding a Bicycle.

    Science.gov (United States)

    Cain, Stephen M; Ashton-Miller, James A; Perkins, Noel C

    2016-01-01

    Humans have ridden bicycles for over 200 years, yet there are no continuous measures of how skill differs between novice and expert. To address this knowledge gap, we measured the dynamics of human bicycle riding in 14 subjects, half of whom were skilled and half were novice. Each subject rode an instrumented bicycle on training rollers at speeds ranging from 1 to 7 m/s. Steer angle and rate, steer torque, bicycle speed, and bicycle roll angle and rate were measured and steering power calculated. A force platform beneath the roller assembly measured the net force and moment that the bicycle, rider and rollers exerted on the floor, enabling calculations of the lateral positions of the system centers of mass and pressure. Balance performance was quantified by cross-correlating the lateral positions of the centers of mass and pressure. The results show that all riders exhibited similar balance performance at the slowest speed. However at higher speeds, the skilled riders achieved superior balance performance by employing more rider lean control (quantified by cross-correlating rider lean angle and bicycle roll angle) and less steer control (quantified by cross-correlating steer rate and bicycle roll rate) than did novice riders. Skilled riders also used smaller steering control input with less variation (measured by average positive steering power and standard deviations of steer angle and rate) and less rider lean angle variation (measured by the standard deviation of the rider lean angle) independent of speed. We conclude that the reduction in balance control input by skilled riders is not due to reduced balance demands but rather to more effective use of lean control to guide the center of mass via center of pressure movements.

  8. On the Skill of Balancing While Riding a Bicycle.

    Directory of Open Access Journals (Sweden)

    Stephen M Cain

    Full Text Available Humans have ridden bicycles for over 200 years, yet there are no continuous measures of how skill differs between novice and expert. To address this knowledge gap, we measured the dynamics of human bicycle riding in 14 subjects, half of whom were skilled and half were novice. Each subject rode an instrumented bicycle on training rollers at speeds ranging from 1 to 7 m/s. Steer angle and rate, steer torque, bicycle speed, and bicycle roll angle and rate were measured and steering power calculated. A force platform beneath the roller assembly measured the net force and moment that the bicycle, rider and rollers exerted on the floor, enabling calculations of the lateral positions of the system centers of mass and pressure. Balance performance was quantified by cross-correlating the lateral positions of the centers of mass and pressure. The results show that all riders exhibited similar balance performance at the slowest speed. However at higher speeds, the skilled riders achieved superior balance performance by employing more rider lean control (quantified by cross-correlating rider lean angle and bicycle roll angle and less steer control (quantified by cross-correlating steer rate and bicycle roll rate than did novice riders. Skilled riders also used smaller steering control input with less variation (measured by average positive steering power and standard deviations of steer angle and rate and less rider lean angle variation (measured by the standard deviation of the rider lean angle independent of speed. We conclude that the reduction in balance control input by skilled riders is not due to reduced balance demands but rather to more effective use of lean control to guide the center of mass via center of pressure movements.

  9. Hypervalent silicon-containing organosilicon derivatives of nitrogen heterocycles

    Energy Technology Data Exchange (ETDEWEB)

    Voronkov, Mikhail G; Trofimova, Ol' ga M; Bolgova, Yu I [A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Irkutsk (Russian Federation); Chernov, Nikolai F [Irkutsk State Pedagogical University (Russian Federation)

    2007-09-30

    The published data on the methods of synthesis, properties and transformations of organosilicon derivatives of nitrogen heterocycles containing a hypervalent silicon atom are generalised and described systematically.

  10. 车锁式打气筒设计%Design of Bicycle Lock Type Pump

    Institute of Scientific and Technical Information of China (English)

    王超; 司慧

    2012-01-01

    The design combines a bicycle lock with a pump, realizing a uniform structure of the two. The application of a dual-pump structure makes the pumping process more efficient. In order to facilitate bicycle riders' relaxation, the air pump can also serve as a stool. Compared with carrying a single air pump or a single bicycle lock, this kind of air pump features lost air pumping cost, easy use, low space requirements, convenience to carry steady and reliable operation.%本设计将自行车车锁与打气筒巧妙地结合在一起,实现了二者结构形式的统一。应用双注气杆式打气结构,使打气效率优于现有的便携式打气筒,为了方便骑行者能够就地休息又附加了凳子的功能。与单独携带气筒、单独使用车锁相比,合二为一的车锁式打气筒成本低,使用、携带方便,节省空间,工作过程稳定、可靠。

  11. Factors of the safety in bicycle traffic in the City of Zagreb and its surrounding

    Directory of Open Access Journals (Sweden)

    Sindik Joško

    2014-01-01

    Full Text Available The aim of this study was to determine the differences in underlying factors of Zagreb cycling, compared to the "types of cyclists" (driving style, i.e. different ways of using bicycles as a means of transport. The study included over 3,000 frequent participants in urban traffic cycling, sample of members of the association Cyclist Union (N = 1259 and snowball sample of "typical" of cyclists, i.e. people who are using the bike, but are not the members of the Cyclist Union (N = 1831, using the conveniently assembled questionnaire. Study participants who bike used in various applications prefer the safest driving style (only on sidewalks and bike paths / lines. Barriers of the weather conditions are ubiquitous in the safest driving style. Daily, weekly and yearly riding a bicycle are more often found in those who prefer the safest driving style. Cyclists who drive with medium secure style (roads with less traffic and lower speeds, more often ride a bike, as compared with those who prefer the safest driving style. Having a better bike line / track and other infrastructure is the most often considered at those with the highest risk driving style. The results provide the guidance for local authorities and for the cyclists to improve the conditions for a safer and more often by bicycle circulation in the City of Zagreb and its surroundings.

  12. Comparative life cycle assessment of ghana-made bamboo-frame bicycle and conventional bicycles assembled and used in the Netherlands

    NARCIS (Netherlands)

    Agyekum, E.O.; Fortuin, K.P.J.; Harst, van der E.J.M.

    2014-01-01

    In order to assess the sustainability of bamboo-framed bicycles produced in Ghana, an environmental and social life cycle assessments (LCA) were performed. For the environmental LCA, a bamboo-frame bicycle was compared with aluminium- and steel-frame bicycles, focussing on processes related to the f

  13. Bicycle helmet use and non-use - recently published research.

    Science.gov (United States)

    Uibel, Stefanie; Müller, Daniel; Klingelhoefer, Doris; Groneberg, David A

    2012-05-25

    Bicycle traumata are very common and especially neurologic complications lead to disability and death in all stages of the life. This review assembles the most recent findings concerning research in the field of bicycle traumata combined with the factor of bicycle helmet use. The area of bicycle trauma research is by nature multidisciplinary and relevant not only for physicians but also for experts with educational, engineering, judicial, rehabilitative or public health functions. Due to this plurality of global publications and special subjects, short time reviews help to detect recent research directions and provide also information from neighbour disciplines for researchers. It can be stated that to date, that although a huge amount of research has been conducted in this area more studies are needed to evaluate and improve special conditions and needs in different regions, ages, nationalities and to create successful prevention programs of severe head and face injuries while cycling.Focus was explicit the bicycle helmet use, wherefore sledding, ski and snowboard studies were excluded and only one study concerning electric bicycles remained due to similar motion structures within this review. The considered studies were all published between January 2010 and August 2011 and were identified via the online databases Medline PubMed and ISI Web of Science.

  14. Test Verification and Design of the Bicycle Frame Parameters

    Institute of Scientific and Technical Information of China (English)

    ZHANG Long; XIANG Zhongxia; LUO Huan; TIAN Guan

    2015-01-01

    Research on design of bicycles is concentrated on mechanism and auto appearance design, however few on matches between the bike and the rider. Since unreasonable human-bike relationship leads to both riders’ worn-out joints and muscle injuries, the design of bicycles should focus on the matching. In order to find the best position of human-bike system, simulation experiments on riding comfort under different riding postures are done with the lifemode software employed to facilitate the cycling process as well as to obtain the best position and the size function of it. With BP neural network and GA, analyzing simulation data, conducting regression analysis of parameters on different heights and bike frames, the equation of best position of human-bike system is gained at last. In addition, after selecting testers, customized bikes based on testers’ height dimensions are produced according to the size function. By analyzing and comparing the experimental data that are collected from testers when riding common bicycles and customized bicycles, it is concluded that customized bicycles are four times even six times as comfortable as common ones. The equation of best position of human-bike system is applied to improve bikes’ function, and the new direction on future design of bicycle frame parameters is presented.

  15. [Bicycle spoke-related injuries in children: emphasise prevention].

    Science.gov (United States)

    Kramer, William L M; Haaring, Gert-Jan

    2011-01-01

    Three children, a 6-year-old boy and two girls aged 5 and 4 years, were seen at an emergency department due to distal lower-leg injuries sustained from the spokes of bicycle wheels. All three patients had been passengers on rear carrying seats of moving bicycles. Only the third bicyclist had used a special child safety seat. The second girl had drawn her foot up from underneath a strap and suffered a tibial fracture later treated with an osteosynthetic plate. The other two patients recovered after conservative casting treatment. Bicycle spoke-related injuries are sustained when the foot or lower limb makes contact with the spokes of a bicycle wheel and usually by children who are bicycle passengers. In the Netherlands, approximately 4600 children are seen at emergency departments with such injuries each year. Bicycle spoke-related accidents can cause severe damage that can result in lengthy recovery periods. Not only physical complications but also psychological ones can occur. The latter are often overlooked but do deserve proper treatment. The physician treating a spoke-related injury is in a good position to advice parents as to preventive measures, particularly on the use of special child safety seats.

  16. Exploration of Visible-Light Photocatalysis in Heterocycle Synthesis and Functionalization: Reaction Design and Beyond.

    Science.gov (United States)

    Chen, Jia-Rong; Hu, Xiao-Qiang; Lu, Liang-Qiu; Xiao, Wen-Jing

    2016-09-20

    Visible-light photocatalysis has recently received increasing attention from chemists because of its wide application in organic synthesis and its significance for sustainable chemistry. This catalytic strategy enables the generation of various reactive species, frequently without stoichiometric activation reagents under mild reaction conditions. Manipulation of these reactive intermediates can result in numerous synthetically useful bond formations in a controllable manner. In this Account, we describe our recent advances in the rational design and strategic application of photocatalysis in the synthesis of various synthetically and biologically important heterocycles. Our main research efforts toward this goal can be classified into four categories: formal cycloaddition and cyclization reactions, radical-mediated olefin functionalization/cyclization cascades, photocatalytic generation and cyclization of N-centered radicals, and photocatalytic functionalization of heterocycles by visible-light-induced dual catalysis. Inspired by the wide application of tertiary amines as reductive additives in photoredox catalysis, we exploited a series of readily accessible or rationally designed tertiary amines with reactive sites in a range of photocatalytic formal cycloaddition and cyclization reactions, providing efficient access to diverse nitrogen heterocycles. Employing various photogenerated radical species, we further developed a series of radical-mediated olefin functionalization/cyclization cascade reactions to successfully assemble various five- and six-membered heterocycles. We have also achieved for the first time the direct catalytic conversion of recalcitrant N-H bonds into neutral N-centered radicals through a visible-light-photocatalytic oxidative deprotonation electron transfer. Using this generic strategy, we have devised several types of radical cyclizations of unsaturated hydrazones, leading to the construction of diversely functionalized pyrazoline and

  17. Heterocyclic Anticancer Compounds: Recent Advances and the Paradigm Shift towards the Use of Nanomedicine’s Tool Box

    Directory of Open Access Journals (Sweden)

    Pedro Martins

    2015-09-01

    Full Text Available The majority of heterocycle compounds and typically common heterocycle fragments present in most pharmaceuticals currently marketed, alongside with their intrinsic versatility and unique physicochemical properties, have poised them as true cornerstones of medicinal chemistry. Apart from the already marketed drugs, there are many other being investigated for their promising activity against several malignancies. In particular, anticancer research has been capitalizing on the intrinsic versatility and dynamic core scaffold of these compounds. Nevertheless, as for any other promising anticancer drugs, heterocyclic compounds do not come without shortcomings. In this review, we provide for a concise overview of heterocyclic active compounds and families and their main applications in medicine. We shall focus on those suitable for cancer therapy while simultaneously addressing main biochemical modes of action, biological targets, structure-activity relationships as well as intrinsic limitation issues in the use of these compounds. Finally, considering the advent of nanotechnology for effective selective targeting of drugs, we shall discuss fundamental aspects and considerations on nanovectorization of such compounds that may improve pharmacokinetic/pharmacodynamic properties of heterocycles.

  18. Reviving a ghost in the history of technology: the social construction of the recumbent bicycle.

    Science.gov (United States)

    Ahmed, Hassaan; Qureshi, Omer Masood; Khan, Abid Ali

    2015-02-01

    Recumbent bicycles have never truly been associated with international cycling. Conventional safety (upright) bicycles have long been at the center of the cycling world, for both sport and transportation. This is despite the fact that recumbent bicycles are faster, more comfortable, and more efficient than the upright bicycles. The aim of this article is to explain the historical and social perspectives that led to the rejection of the recumbent bicycle by utilizing the theory of Social Construction of Technology (SCOT) and Bijker's two power theory, providing a contrast with the adoption of the safety bicycle.

  19. ROUTE CHOICE MODELLING FOR BICYCLE TRIPS

    Directory of Open Access Journals (Sweden)

    Ehsan Beheshtitabar

    2014-06-01

    Full Text Available This paper intends to find out which parameters have the highest influence on bicyclists’ route-choice-behaviour and how they contribute. There are many attributes considered throughout different studies that are favoured by cyclists. The attributes are the basis for generating a function which predicts the route choice of cyclists. The paper aims at making a comparison between distance-based routes and attribute-based routes. The model for creating the bicycle route choice program is based on the network model of Norrköping, Sweden. The preferred attributes of the model each assign a weight in the cost function of the model for each link of the urban network. The algorithm of the lowest cost function route searches the shortest path in terms of assigned link costs over the whole network. For comparing the results of the cost function and the shortest route (between an origin-destination, the model has a shortest path finding algorithm between different Origin and Destination pairs implemented. It has been viewed that around 25% of all cumulative routes do not show any distance differences between the shortest path distance and attributes based solution. With the used weights of the Standard scenario, it can be seen that the trade-off between shortest distance and safety respectively comfort can be optimized, fulfilling both criteria (distance and safety/comfort.

  20. Bicycle, city and education: search moves

    Directory of Open Access Journals (Sweden)

    Sheila Hempkemeyer

    2016-07-01

    Full Text Available This study comes from a Master’s degree in Education research, which investigates narratives of “pedaling beings” starting from the relationship bicycle-city. The theoretical assumptions lean on the Cultural Studies and concepts about education, culture, everyday life, experience and narratives. Researching with narratives closes everyday life and promotes co-authorship to the subjects in the paper. The article puts in discussion some forms of contemporary subjectivity, resistance techniques and expression. A study that builds narratives and reflections about the experiences of theses hybrid subjects and their everyday life, questioning their way of life in the city. Thinking in this urban medley is connect the environment and the dynamic of these pedaling bodies, emerging other ways of education and interaction with the medium, weaving multiple affectations in aesthetics, poetry, politics, opening breaches to reflect in the everyday happenings. The article also discusses the movements in research and the effects in those who research and are researched.

  1. Built environment influences on healthy transportation choices: bicycling versus driving.

    Science.gov (United States)

    Winters, Meghan; Brauer, Michael; Setton, Eleanor M; Teschke, Kay

    2010-12-01

    A growing body of evidence links the built environment to physical activity levels, health outcomes, and transportation behaviors. However, little of this research has focused on cycling, a sustainable transportation option with great potential for growth in North America. This study examines associations between decisions to bicycle (versus drive) and the built environment, with explicit consideration of three different spatial zones that may be relevant in travel behavior: trip origins, trip destinations, and along the route between. We analyzed 3,280 utilitarian bicycle and car trips in Metro Vancouver, Canada made by 1,902 adults, including both current and potential cyclists. Objective measures were developed for built environment characteristics related to the physical environment, land use patterns, the road network, and bicycle-specific facilities. Multilevel logistic regression was used to model the likelihood that a trip was made by bicycle, adjusting for trip distance and personal demographics. Separate models were constructed for each spatial zone, and a global model examined the relative influence of the three zones. In total, 31% (1,023 out of 3,280) of trips were made by bicycle. Increased odds of bicycling were associated with less hilliness; higher intersection density; less highways and arterials; presence of bicycle signage, traffic calming, and cyclist-activated traffic lights; more neighborhood commercial, educational, and industrial land uses; greater land use mix; and higher population density. Different factors were important within each spatial zone. Overall, the characteristics of routes were more influential than origin or destination characteristics. These findings indicate that the built environment has a significant influence on healthy travel decisions, and spatial context is important. Future research should explicitly consider relevant spatial zones when investigating the relationship between physical activity and urban form.

  2. Resolution of P-stereogenic P-heterocycles via the formation of diastereomeric molecular and coordination complexes (a review).

    Science.gov (United States)

    Bagi, Péter; Ujj, Viktória; Czugler, Mátyás; Fogassy, Elemér; Keglevich, György

    2016-02-01

    TADDOL derivatives and the Ca(2+)-salts of tartaric acid derivatives were found to be versatile and generally applicable resolving agents for the preparation of the enantiomers of P-stereogenic heterocyclic phosphine oxides and phosphinates via the formation of the corresponding diastereomeric molecular and coordination complexes. A few of the diastereomeric intermediates were characterized by single crystal X-ray crystallography to gain insights into the binding mode of the corresponding heterocyclic phosphine oxide ("guest") and the resolving agent ("host") and to study the underlying phenomenon of enantiomeric recognition. PMID:26564410

  3. Nickel N-heterocyclic carbene complexes in homogeneous catalysis

    NARCIS (Netherlands)

    Berding, Joris

    2009-01-01

    Described in this thesis are the investigations into the chemistry of N-heterocyclic carbene (NHC) ligands and transition-metal complexes thereof. Specifically, a variety of N-heterocyclic carbene complexes of nickel were prepared, characterized and used as catalysts in three types of homogeneous ca

  4. Recent Advances in the Application of SelectfluorTMF-TEDA-BF4 as a Versatile Mediator or Catalyst in Organic Synthesis

    Directory of Open Access Journals (Sweden)

    Stojan Stavber

    2011-07-01

    Full Text Available SelectfluorTM F-TEDA-BF4 (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo [2.2.2]octane bis(tetrafluoroborate is not only one of the most efficient and popular reagents for electrophilic fluorination, but as a strong oxidant is also a convenient mediator or catalyst of several “fluorine-free” functionalizations of organic compounds. Its applications as a mediator in transformations of oxidizable functional groups or gold-catalyzed C-C and C-heteroatom oxidative coupling reactions, a catalyst in formation of various heterocyclic rings, a reagent or catalyst of various functionalizations of electron-rich organic compounds (iodination, bromination, chlorination, nitration, thiocyanation, sulfenylation, alkylation, alkoxylation, a catalyst of one-pot-multi-component coupling reactions, a catalyst of regioselective ring opening of epoxides, a deprotection reagent for various protecting groups, and a mediator for stereoselective rearrangement processes of bicyclic compounds are reviewed and discussed.

  5. Titanium-catalyzed multicomponent couplings: efficient one-pot syntheses of nitrogen heterocycles.

    Science.gov (United States)

    Odom, Aaron L; McDaniel, Tanner J

    2015-11-17

    Nitrogen-based heterocycles are important frameworks for pharmaceuticals, natural products, organic dyes for solar cells, and many other applications. Catalysis for the formation of heterocyclic scaffolds, like many C-C and C-N bond-forming reactions, has focused on the use of rare, late transition metals like palladium and gold. Our group is interested in the use of Earth-abundant catalysts based on titanium to generate heterocycles using multicomponent coupling strategies, often in one-pot reactions. To be of maximal utility, the catalysts need to be easily prepared from inexpensive reagents, and that has been one guiding principle in the research. For this purpose, a series of easily prepared pyrrole-based ligands has been developed. Titanium imido complexes are known to catalyze the hydroamination of alkynes, and this reaction has been used to advantage in the production of α,β-unsaturated imines from 1,3-enynes and pyrroles from 1,4-diynes. Likewise, catalyst design can be used to find complexes applicable to hydrohydrazination, coupling of a hydrazine and alkyne, which is a method for the production of hydrazones. Many of the hydrazones synthesized are converted to indoles through Fischer cyclization by addition of a Lewis acid. However, more complex products are available in a single catalytic cycle through coupling of isonitriles, primary amines, and alkynes to give tautomers of 1,3-diimines, iminoamination (IA). The products of IA are useful intermediates for the one-pot synthesis of pyrazoles, pyrimidines, isoxazoles, quinolines, and 2-amino-3-cyanopyridines. The regioselectivity of the reactions is elucidated in some detail for some of these heterocycles. The 2-amino-3-cyanopyridines are synthesized through isolable intermediates, 1,2-dihydro-2-iminopyridines, which undergo Dimroth rearrangement driven by aromatization of the pyridine ring; the proposed mechanism of the reaction is discussed. The IA-based heterocyclic syntheses can be accomplished

  6. Synthesis and Luminescent Properties of Two New Triphenylamine-based Compounds with Heterocyclic Ring as Conjugation Bridge

    Institute of Scientific and Technical Information of China (English)

    LI,Qian-Qian; DI,Chong-An; YU,Gui; LIU,Yun-Qi; LI,Zhen; QIN,Jin-Gui

    2008-01-01

    Two new "D-π-D" type triphenylamine-based compounds with a heterocyclic ring,furan or thiophene,as a conjugation bridge were synthesized through a normal Wittig reaction which exhibited good thermal stability and strong luminescence.The preliminary light-emitting diode results indicate that they are promising candidates for the practical application.

  7. Modeling the Distribution Characteristics of Urban Public Bicycle Rental Duration

    Directory of Open Access Journals (Sweden)

    Shuichao Zhang

    2016-01-01

    Full Text Available In order to model the distribution characteristics of public bicycle rental durations, individual journey data for three cities in China (Ningbo, Hangzhou, and Beijing, for weekdays, was obtained. The distribution curves for public bicycle rental duration in the three cities were found to be extremely similar, with small differences among the weekdays. The basic parameters such as the average rental duration, the rental duration corresponding to the maximum rental frequency, and the rental duration corresponding to 75% degree were then calculated. On this basis, the radioactive decay law from physics was used to establish a theoretical model for the relationship between rental frequency and rental duration. The data on public bicycle rental duration in Ningbo, Hangzhou, and Beijing were used to test the model and produce a corrected theoretical model. The results indicate that the relationship between rental frequency and rental duration obeys the decay law. The study results provide important theoretical support for the rental station planning of bicycle sharing systems, as well as the allocation, operation, and dispatch of public bicycles.

  8. Bicycling injury hospitalisation rates in Canadian jurisdictions: analyses examining associations with helmet legislation and mode share

    OpenAIRE

    Teschke, Kay; Koehoorn, Mieke; Shen, Hui; Dennis, Jessica

    2015-01-01

    Objectives The purpose of this study was to calculate exposure-based bicycling hospitalisation rates in Canadian jurisdictions with different helmet legislation and bicycling mode shares, and to examine whether the rates were related to these differences. Methods Administrative data on hospital stays for bicycling injuries to 10 body region groups and national survey data on bicycling trips were used to calculate hospitalisation rates. Rates were calculated for 44 sex, age and jurisdiction st...

  9. Investigation with Bluetooth Sensors of Bicycle Travel Time Estimation on a Short Corridor

    OpenAIRE

    Zhenyu Mei; Dianhai Wang; Jun De Chen

    2012-01-01

    Accurate travel time information acquisition is essential to the effective planning and management of bicycle travel conditions. Traditionally, video camera data have been used as the primary source for measuring the quality of bicycle travel time. This paper deals with an investigation of bicycle travel time estimation on a short corridor, using Bluetooth sensors, based on field survey of travel time at one arterial road in Hangzhou. Usually bicycle travel time estimates with Bluetooth senso...

  10. Influences of infrastructure and attitudes to health on value of travel time savings in bicycle journeys

    OpenAIRE

    Björklund, Gunilla; Mortazavi , Reza

    2013-01-01

    In this paper we investigate how attitudes to health and exercise in connection with cycling influence the estimation of values of travel time savings in different kinds of bicycle environments (mixed traffic, bicycle lane in the road way, bicycle path next to the road, and bicycle path not in connection with the road). The results, based on two Swedish stated choice studies, suggest that the values of travel time savings are lower when cycling in better conditions. Surprisingly, the responde...

  11. Predicting Public Bicycle Adoption Using the Technology Acceptance Model

    Directory of Open Access Journals (Sweden)

    Benjamin T. Hazen

    2015-10-01

    Full Text Available Bicycle sharing programs provide a sustainable mode of urban transportation. Although cities across the globe have developed these systems for their citizens and visitors, usage rates are not as high as anticipated. This research uses the technology acceptance model as the basis to understand one’s intention to adopt bicycle sharing programs. Using survey data derived from 421 participants in Beijing, China, the proposed covariance-based structural equation model consisting of perceived quality, perceived convenience, and perceived value is found to predict 50.5% of the variance in adoption intention. The findings of this research contribute to theory and practice in the burgeoning literature on public bicycle systems and sustainable urban transportation by offering a theoretical lens through which to consider system adoption, and providing information to practitioners as to what factors might contribute most to adoption.

  12. Using magnetorheological fluids in an innovative hybrid bicycle damper

    Science.gov (United States)

    Shiao, Y. J.; Nguyen, T. S.

    2015-12-01

    Magnetorheological fluids are capable of changing their viscosity quickly. This can provide good controllability and fast dynamic response. A conventional passive suspension system with air spring or hydraulic damper has simple design and financial benefit for bicycles, but its operation is uncontrollable and non-adaptive. This paper presented a semi-active hybrid bicycle suspension system which combines conventional air spring and a new magnetorheological damping brake together to reduce vibration of a bicycle. A multi-layer magnetorheological brake and linkage mechanism are connected to bike fork to form the adaptive damping part of the innovative hybrid suspension system. The simulation results proved that the semi-active suspension system can reduce bike vibration effectively.

  13. Interventions in Bicycle Infrastructure, Lessons from Dutch and Danish Cases

    DEFF Research Database (Denmark)

    van Goeverden, K.; Nielsen, Thomas Alexander Sick; Harder, Henrik;

    2015-01-01

    Today the interest in cycling is increasing worldwide and in many countries authorities are faced with the question how cycling can be promoted efficiently. In the Netherlands and Denmark, this question came up already in the 1970s when the downsides of the rapidly increasing motorisation became...... evident. At the time, in both countries large scale interventions in bicycle infrastructure were introduced and evaluated extensively in order to create knowledge on efficient promoting of cycling in urban areas. The interventions included the construction of new bicycle routes on urban arterials in some...... was used in both countries for formulating guidelines for road and bicycle infrastructure design. However, at that time the study results were not shared with the international scientific audience. The paper describes briefly the classical cases and the main study results. The outcomes of the classical...

  14. Bicycling crash characteristics: An in-depth crash investigation study.

    Science.gov (United States)

    Beck, Ben; Stevenson, Mark; Newstead, Stuart; Cameron, Peter; Judson, Rodney; Edwards, Elton R; Bucknill, Andrew; Johnson, Marilyn; Gabbe, Belinda

    2016-11-01

    The aim of this study was to describe the crash characteristics and patient outcomes of a sample of patients admitted to hospital following bicycle crashes. Injured cyclists were recruited from the two major trauma services for the state of Victoria, Australia. Enrolled cyclists completed a structured interview, and injury details and patient outcomes were extracted from the Victorian State Trauma Registry (VSTR) and the Victorian Orthopaedic Trauma Outcomes Registry (VOTOR). 186 cyclists consented to participate in the study. Crashes commonly occurred during daylight hours and in clear weather conditions. Two-thirds of crashes occurred on-road (69%) and were a combination of single cyclist-only events (56%) and multi-vehicle crashes (44%). Of the multi-vehicle crashes, a motor vehicle was the most common impact partner (72%) and distinct pre-crash directional interactions were observed between the cyclist and motor vehicle. Nearly a quarter of on-road crashes occurred when the cyclist was in a marked bicycle lane. Of the 31% of crashes that were not on-road, 28 (15%) occurred on bicycle paths and 29 (16%) occurred in other locations. Crashes on bicycle paths commonly occurred on shared bicycle and pedestrian paths (83%) and did not involve another person or vehicle. Other crash locations included mountain bike trails (39%), BMX parks (21%) and footpaths (18%). While differences in impact partners and crash characteristics were observed between crashes occurring on-road, on bicycle paths and in other locations, injury patterns and severity were similar. Most cyclists had returned to work at 6 months post-injury, however only a third of participants reported a complete functional recovery. Further research is required to develop targeted countermeasures to address the risk factors identified in this study. PMID:27544886

  15. Bicycling crash characteristics: An in-depth crash investigation study.

    Science.gov (United States)

    Beck, Ben; Stevenson, Mark; Newstead, Stuart; Cameron, Peter; Judson, Rodney; Edwards, Elton R; Bucknill, Andrew; Johnson, Marilyn; Gabbe, Belinda

    2016-11-01

    The aim of this study was to describe the crash characteristics and patient outcomes of a sample of patients admitted to hospital following bicycle crashes. Injured cyclists were recruited from the two major trauma services for the state of Victoria, Australia. Enrolled cyclists completed a structured interview, and injury details and patient outcomes were extracted from the Victorian State Trauma Registry (VSTR) and the Victorian Orthopaedic Trauma Outcomes Registry (VOTOR). 186 cyclists consented to participate in the study. Crashes commonly occurred during daylight hours and in clear weather conditions. Two-thirds of crashes occurred on-road (69%) and were a combination of single cyclist-only events (56%) and multi-vehicle crashes (44%). Of the multi-vehicle crashes, a motor vehicle was the most common impact partner (72%) and distinct pre-crash directional interactions were observed between the cyclist and motor vehicle. Nearly a quarter of on-road crashes occurred when the cyclist was in a marked bicycle lane. Of the 31% of crashes that were not on-road, 28 (15%) occurred on bicycle paths and 29 (16%) occurred in other locations. Crashes on bicycle paths commonly occurred on shared bicycle and pedestrian paths (83%) and did not involve another person or vehicle. Other crash locations included mountain bike trails (39%), BMX parks (21%) and footpaths (18%). While differences in impact partners and crash characteristics were observed between crashes occurring on-road, on bicycle paths and in other locations, injury patterns and severity were similar. Most cyclists had returned to work at 6 months post-injury, however only a third of participants reported a complete functional recovery. Further research is required to develop targeted countermeasures to address the risk factors identified in this study.

  16. Bicycle Training for Youth with Down Syndrome and Autism Spectrum Disorders

    Science.gov (United States)

    MacDonald, Megan; Esposito, Phil; Hauck, Janet; Jeong, Irully; Hornyak, Joseph; Argento, Angela; Ulrich, Dale A.

    2012-01-01

    Children with Down syndrome (DS) and autism spectrum disorders (ASD) frequently have difficulty riding a two-wheel bicycle. The purpose of this study was to investigate an intervention using an adapted bicycle and individualized instruction to teach 71 youth to ride a standard two-wheel bicycle. Youth with DS (n = 30) and ASD (n = 41) between the…

  17. A City Plans for Bicycles: A Case Study of Olympia, Washington.

    Science.gov (United States)

    Litman, Todd

    1990-01-01

    Discusses community planning for bicycling programs with emphasis on safety education for children and adults, enforcement of bicycle laws, engineering improvements, and special events. Describes how Olympia improved existing bicycling facilities and summarizes planning, communication, engineering, and policy issues addressed. (SV)

  18. Bicycle cycles and mobility patterns - Exploring and characterizing data from a community bicycle program

    CERN Document Server

    Kaltenbrunner, Andreas; Grivolla, Jens; Codina, Joan; Banchs, Rafael

    2008-01-01

    This paper provides an analysis of human mobility data in an urban area using the amount of available bikes in the stations of the community bicycle program Bicing in Barcelona. The data was obtained by periodic mining of a KML-file accessible through the Bicing website. Although in principle very noisy, after some preprocessing and filtering steps the data allows to detect temporal patterns in mobility as well as identify residential, university, business and leisure areas of the city. The results lead to a proposal for an improvement of the bicing website, including a prediction of the number of available bikes in a certain station within the next minutes/hours. Furthermore a model for identifying the most probable routes between stations is briefly sketched.

  19. Experimental and mathematical car-bicycle collision simulations.

    OpenAIRE

    Huybers, J.J.W. & Janssen, E.G.

    1988-01-01

    The results of 35 mathematical simulations will be used to get a better insight in car-bicycle collisions. This information will be used later on to formulate hypotheses to be tested in an accident investigation project. In this paper special attention is given to the influence of the shape of the car and the dimensions of the bicycle/cyclist on the severity of the impacts. It is known that the speed of the car at impact is an important parameter in the resulting injury severity of the cyclis...

  20. Biosynthesis of oxygen and nitrogen-containing heterocycles in polyketides

    Science.gov (United States)

    Hemmerling, Franziska

    2016-01-01

    Summary This review highlights the biosynthesis of heterocycles in polyketide natural products with a focus on oxygen and nitrogen-containing heterocycles with ring sizes between 3 and 6 atoms. Heterocycles are abundant structural elements of natural products from all classes and they often contribute significantly to their biological activity. Progress in recent years has led to a much better understanding of their biosynthesis. In this context, plenty of novel enzymology has been discovered, suggesting that these pathways are an attractive target for future studies. PMID:27559404

  1. Generating and trapping metalla-N-heterocyclic carbenes.

    Science.gov (United States)

    Ruiz, Javier; García, Lucía; Vivanco, Marilín; Berros, Ángela; Van der Maelen, Juan Francisco

    2015-03-27

    By means of a combined experimental and theoretical approach, the electronic features and chemical behavior of metalla-N-heterocyclic carbenes (MNHCs, N-heterocyclic carbenes containing a metal atom within the heterocyclic skeleton) have been established and compared with those of classical NHCs. MNHCs are strongly basic (proton affinity and pK(a) values around 290 kcal mol(-1) and 36, respectively) with a narrow singlet-triplet gap (around 23 kcal mol(-1)). MNHCs can be generated from the corresponding metalla-imidazolium salts and trapped by addition of transition-metal complexes affording the corresponding heterodimetallic dicarbene derivatives, which can serve as carbene transfer agents.

  2. Head injuries and bicycle helmet laws.

    Science.gov (United States)

    Robinson, D L

    1996-07-01

    The first year of the mandatory bicycle helmet laws in Australia saw increased helmet wearing from 31% to 75% of cyclists in Victoria and from 31% of children and 26% of adults in New South Wales (NSW) to 76% and 85%. However, the two major surveys using matched before and after samples in Melbourne (Finch et al. 1993; Report No. 45, Monash Univ. Accident Research Centre) and throughout NSW (Smith and Milthorpe 1993; Roads and Traffic Authority) observed reductions in numbers of child cyclists 15 and 2.2 times greater than the increase in numbers of children wearing helmets. This suggests the greatest effect of the helmet law was not to encourage cyclists to wear helmets, but to discourage cycling. In contrast, despite increases to at least 75% helmet wearing, the proportion of head injuries in cyclists admitted or treated at hospital declined by an average of only 13%. The percentage of cyclists with head injuries after collisions with motor vehicles in Victoria declined by more, but the proportion of head injured pedestrians also declined; the two followed a very similar trend. These trends may have been caused by major road safety initiatives introduced at the same time as the helmet law and directed at both speeding and drink-driving. The initiatives seem to have been remarkably effective in reducing road trauma for all road users, perhaps affecting the proportions of victims suffering head injuries as well as total injuries. The benefits of cycling, even without a helmet, have been estimated to outweigh the hazards by a factor of 20 to 1 (Hillman 1993. Cycle helmets-the case for and against. Policy Studies Institute, London). Consequently, a helmet law, whose most notable effect was to reduce cycling, may have generated a net loss of health benefits to the nation. Despite the risk of dying from head injury per hour being similar for unhelmeted cyclists and motor vehicle occupants, cyclists alone have been required to wear head protection. Helmets for motor

  3. An international review of the frequency of single-bicycle crashes (SBCs) and their relation to bicycle modal share

    DEFF Research Database (Denmark)

    Schepers, Paul; Agerholm, Niels; Amoros, Emmanuelle;

    2015-01-01

    . Different countries show a range of values between 5% and 30%. Between 60% and 95% of cyclists admitted to hospitals or treated at emergency departments are victims of SBCs. The proportion of all injured cyclists who are injured in SBCs is unrelated to the share of cycling in the modal split. The share...... of SBC casualties among the total number of road crash casualties increases proportionally less than the increase in bicycle modal share. Conclusions While most fatal injuries among cyclists are due to motor vehicle–bicycle crashes, most hospital admissions and emergency department attendances result...

  4. Evaluation and application of microwave-assisted extraction and dispersive liquid-liquid microextraction followed by high-performance liquid chromatography for the determination of polar heterocyclic aromatic amines in hamburger patties.

    Science.gov (United States)

    Aeenehvand, Saeed; Toudehrousta, Zahra; Kamankesh, Marzieh; Mashayekh, Morteza; Tavakoli, Hamid Reza; Mohammadi, Abdorreza

    2016-01-01

    This study developed an analytical method based on microwave-assisted extraction and dispersive liquid-liquid microextraction followed by high-performance liquid chromatography for the determination of three polar heterocyclic aromatic amines from hamburger patties. Effective parameters controlling the performance of the microextraction process, such as the type and volume of extraction and disperser solvents, microwave time, nature of alkaline aqueous solution, pH and salt amount, were optimized. The calibration graphs were linear in the range of 1-200 ng g(-1), with a coefficient of determination (R(2)) better than 0.9993. The relative standard deviations (RSD) for seven analyses were between 3.2% and 6.5%. The recoveries of those compounds in hamburger patties were from 90% to 105%. Detection limits were between 0.06 and 0.21 ng g(-1). A comparison of the proposed method with the existing literature demonstrates that it is a simple, rapid, highly selective and sensitive, and it gives good enrichment factors and detection limits for determining HAAs in real hamburger patties samples.

  5. Solid‐Phase Synthesis of Structurally Diverse Heterocycles by an Amide–Ketone Condensation/N‐Acyliminium Pictet–Spengler Sequence

    DEFF Research Database (Denmark)

    Komnatnyy, Vitaly V.; Givskov, Michael Christian; Nielsen, Thomas Eiland

    2012-01-01

    of a tethered nucleophile, a second cyclization reaction results in the formation of a fused bicyclic ring system. The scope of the methodology was demonstrated by several combinations of substituted ketones and nucleophiles, the latter conveniently originating from amino acids with functionalized side chains......An efficient approach for the solid‐phase synthesis of structurally diverse heterocyclic compounds is presented. Under acidic reaction conditions, peptidic levulinamides undergo intramolecular ketone–amide condensation reactions to form cyclic N‐acyliminium intermediates. In the presence......, such as tryptophan, substituted phenylalanines, and cysteine. The cyclization sequence provides diastereomerically pure products in high yields. In one extension of the methodology, the resulting relative stereochemistry of the products enables the formation of bridged ring systems by a unique cyclative release...

  6. "Walking" Along a Free Rotating Bicycle Wheel (Round and Round)

    CERN Document Server

    Guemez, Julio

    2016-01-01

    We describe the kinematics, dynamics and also some energetic issues related to the Marta mouse motion when she walks on top of a horizontal bicycle wheel, which is free to rotate like a merry-to-go round, as presented recently by Paul Hewitt in the Figuring Physics section of this magazine.

  7. The safety impact of a yellow bicycle jacket

    DEFF Research Database (Denmark)

    Lahrmann, Harry; Madsen, Tanja Kidholm Osmann

    2016-01-01

    of the project, i.e. after a year. The safety effect of the bicycle jacket was analysed by comparing the number of self-reported accident for the test and control group. The self-reported accidents showed that the test group had 38 % fewer personal injury accidents with other road users – so-called multi...

  8. Consumers’ preferences for “bicycle poultry” in Benin

    DEFF Research Database (Denmark)

    Sodjinou, Epiphane; Henningsen, Arne; Koudande, Delphin O.;

    2015-01-01

    Village poultry, also termed "bicycle poultry," is produced in scavenging farming systems and is a chewy meat with a low fat content, and constitutes an important source of meat in many African countries. This study investigates consumers’ preferences regarding the physical traits of these birds ...

  9. Mapping Bicycle Crash Risk Patterns on the Local Scale

    Directory of Open Access Journals (Sweden)

    Martin Loidl

    2016-09-01

    Full Text Available Currently, mainly aggregated statistics are used for bicycle crash risk calculations. Thus, the understanding of spatial patterns at local scale levels remains vague. Using an agent-based flow model and a bicycle crash database covering 10 continuous years of observation allows us to calculate and map the crash risk on various spatial scales for the city of Salzburg (Austria. In doing so, we directly account for the spatial heterogeneity of crash occurrences. Additionally, we provide a measure for the statistical robustness on the level of single reference units and consider modifiable areal unit problem (MAUP effects in our analysis. This study is the first of its kind. The results facilitate a better understanding of spatial patterns of bicycle crash rates on the local scale. This is especially important for cities that strive to improve the safety situation for bicyclists in order to address prevailing safety concerns that keep people from using the bicycle as a utilitarian mode of (urban transport.

  10. Utilizing the Bicycle for Non-Traditional Activities

    Science.gov (United States)

    Maina, Michael P.; Maina, Julie Schlegel; Sebek, Ludek; Hoffmanova, Jana; Kane, Jennifer Jackson

    2012-01-01

    This article examines the bicycle as not simply a means of transportation or as an exercise device, but rather as a vehicle for teambuilding and problem solving activities within a physical education curriculum. The activities described in this article focus on bike-centered initiatives that foster creative problem solving. They have universal…

  11. Bicyclic graphs with exactly two main signless Laplacian eigenvalues

    CERN Document Server

    Huang, He

    2012-01-01

    A signless Laplacian eigenvalue of a graph $G$ is called a main signless Laplacian eigenvalue if it has an eigenvector the sum of whose entries is not equal to zero. In this paper, all connected bicyclic graphs with exactly two main eigenvalues are determined.

  12. 77 FR 39927 - Vehicles and Traffic Safety-Bicycles

    Science.gov (United States)

    2012-07-06

    ... family--they bicycle to visit points of interest, to be healthy, and because it's fun. The National Park... that, at a minimum, the plan: Evaluates the suitability of existing trail surface and soil condition... objectives and will not disturb wildlife or park resources. See NPS Management Policies 2006,...

  13. Experimental and mathematical car-bicycle collision simulations.

    NARCIS (Netherlands)

    Huybers, J.J.W. & Janssen, E.G.

    1988-01-01

    The results of 35 mathematical simulations will be used to get a better insight in car-bicycle collisions. This information will be used later on to formulate hypotheses to be tested in an accident investigation project. In this paper special attention is given to the influence of the shape of the

  14. Bicyclic peptide inhibitor of urokinase-type plasminogen activator

    DEFF Research Database (Denmark)

    Roodbeen, Renée; Jensen, Berit Paaske; Jiang, Longguang;

    2013-01-01

    The development of protease inhibitors for pharmacological intervention has taken a new turn with the use of peptide-based inhibitors. Here, we report the rational design of bicyclic peptide inhibitors of the serine protease urokinase-type plasminogen activator (uPA), based on the established...

  15. Expedition Paris-Beijing by Bicycle 2008 Launched

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>From March 15 to17, at the invitation of the Euro-Chinese Friendship Association (ECFA) of France, a CPAFFC representative attended the launching ceremony of the Expedition Paris-Beijing by Bicycle 2008 in Paris, during which he met with officials of the National Commission on Decentralized Cooperation (Commission Nationale de la Cooperation Decentralisee-CNCD) of France.

  16. Synthesis and anticonvulsant activity of novel bicyclic acidic amino acids

    DEFF Research Database (Denmark)

    Conti, Paola; De Amici, Marco; Joppolo Di Ventimiglia, Samuele;

    2003-01-01

    Bicyclic acidic amino acids (+/-)-6 and (+/-)-7, which are conformationally constrained homologues of glutamic acid, were prepared via a strategy based on a 1,3-dipolar cycloaddition. The new amino acids were tested toward ionotropic and metabotropic glutamate receptor subtypes; both of them...

  17. Efficiency of choice set generation methods for bicycle routes

    DEFF Research Database (Denmark)

    Halldórsdóttir, Katrín; Rieser-Schussler, Nadine; Axhausen, Kay W.;

    2014-01-01

    for scenic routes, dedicated cycle lanes, and road type. Data consisted of 778 bicycle trips traced by GPS and carried out by 139 persons living in the Greater Copenhagen Area, in Denmark. Results suggest that both the breadth first search on link elimination and the doubly stochastic generation function...

  18. Use and activity levels on newly built bicycle playgrounds

    DEFF Research Database (Denmark)

    Schipperijn, Jasper; Hansen, Christine Kier; Rask, Simon

    2015-01-01

    Increasing the use of urban green space (UGS) as well as increasing cycling could potentially help address the growing inactivity problem. Three bicycle playgrounds were designed based on a participatory process and afterwards constructed in the UGS along a cycle-route on the historic outer defen...

  19. A Formal Synthesis of ( + )-Cassiol Exploiting Meyers' Bicyclic Lactam Methodology

    Institute of Scientific and Technical Information of China (English)

    SHEN,Xin(沈鑫); WU,Yi-Kang(伍贻康); ZHANG,Fan(张帆)

    2002-01-01

    A formal synthesis of ( + )-cassiol using (1S,2S)-2-amino-1-(4- nitrophenyl)-1,3-propanediol as chiral auxiliary is reported.The quaternary chiral center in the molecule was constructed by sequential alkylation of a bicyclic lactam (prepared from the aforementioned auxiliary and 5-oxo-heptanlic acid) with methyl iodide and benzyloxymethyl chloride.

  20. Synthesis and Antimicrobial Evaluation of Some Heterocyclic Chalcone Derivatives

    Directory of Open Access Journals (Sweden)

    Essam Mohamed Sharshira

    2011-03-01

    Full Text Available Some new heterocyclic compounds containing isoxazole, pyrazole and oxadiazole ring systems were prepared from various chalcones. The synthesized compounds have been characterized by elemental analysis and spectral methods. These compounds were screened for their antimicrobial activities.

  1. Synthesis and Antimicrobial Evaluation of Some Heterocyclic Chalcone Derivatives

    OpenAIRE

    Essam Mohamed Sharshira; Nagwa Mohamed Mahrous Hamada

    2011-01-01

    Some new heterocyclic compounds containing isoxazole, pyrazole and oxadiazole ring systems were prepared from various chalcones. The synthesized compounds have been characterized by elemental analysis and spectral methods. These compounds were screened for their antimicrobial activities.

  2. Bicycle Conversion Factor Calibration at Two-Phase Intersections in Mixed Traffic Flows

    Institute of Scientific and Technical Information of China (English)

    WANG Dianhai; LIANG Chunyan; JING Chunguang; WANG Guohua

    2007-01-01

    Chinese traffic is typically composed of bicycles and motor vehicles on the same road. The efficiency of bicycle traffic in time and space at intersections was investigated for eight typical intersections in the cities of Tianjin, Shenyang, and Changchun, all in China, by means of video recording. Models were developed to calculate the through bicycle traffic and the left-turn bicycle traffic conversion factors in intersections where bicycles and motor vehicles share the same road. The results indicate that the through bicycle conversion factor is 0.28 and the left-turn bicycle conversion factor is 0.33. This conclusion differs from the current value used in China. More research on the conversion factor is necessary to evaluate the impact of intersections.

  3. Nickel N-heterocyclic carbene complexes in homogeneous catalysis

    OpenAIRE

    Berding, Joris

    2009-01-01

    Described in this thesis are the investigations into the chemistry of N-heterocyclic carbene (NHC) ligands and transition-metal complexes thereof. Specifically, a variety of N-heterocyclic carbene complexes of nickel were prepared, characterized and used as catalysts in three types of homogeneous catalytic processes. First, nickel(II) complexes of monodentate NHC ligands were successfully used as catalysts in the hydrosilylation of internal alkynes. Second, nickel(II) complexes bearing bident...

  4. Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates.

    Science.gov (United States)

    Haji, Mohammad

    2016-01-01

    Multicomponent reactions (MCRs) are one of the most important processes for the preparation of highly functionalized organic compounds in modern synthetic chemistry. As shown in this review, they play an important role in organophosphorus chemistry where phosphorus reagents are used as substrates for the synthesis of a wide range of phosphorylated heterocycles. In this article, an overview about multicomponent reactions used for the synthesis of heterocyclic compounds bearing a phosphonate group on the ring is given. PMID:27559377

  5. Novel synthetic methodologies for the synthesis of heterocyclic rings

    OpenAIRE

    Oswald, Magalie Florence

    2010-01-01

    Part 1. Synthesis of Stereodefined Heterocyclic Rings. We wish to report the development of novel methodology for the synthesis of stereodefined heterocyclic rings, which could be used for the synthesis of natural products containing for example tetrahydrofuran motifs, such as members of the pamamycin family. Due to their ambivalent properties, organoaluminium reagents can easily react with acetals by transfering an alkyl group after prior coordination with the substrates. This work has led t...

  6. Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

    Science.gov (United States)

    2016-01-01

    Summary Multicomponent reactions (MCRs) are one of the most important processes for the preparation of highly functionalized organic compounds in modern synthetic chemistry. As shown in this review, they play an important role in organophosphorus chemistry where phosphorus reagents are used as substrates for the synthesis of a wide range of phosphorylated heterocycles. In this article, an overview about multicomponent reactions used for the synthesis of heterocyclic compounds bearing a phosphonate group on the ring is given. PMID:27559377

  7. Bicycle injuries: a matter of mechanism and age.

    Science.gov (United States)

    Siman-Tov, Maya; Jaffe, Dena H; Peleg, Kobi

    2012-01-01

    Bicycle riding is a popular form of recreation with positive health and environmental effects. These road users are vulnerable to serious injuries, especially when motor vehicles are involved. The goal of this study was to characterize cyclist-related injuries according to motor vehicle involvement for adults versus children. A retrospective study was carried out using data from 11 trauma centers in the Israeli National Trauma Registry (2001-2007). Injuries were classified according to whether a motor vehicle was involved, and differences in injury characteristics were assessed for adults (18+ years) versus children (1-17 years). A total of 5529 patients were hospitalized for bicycle injuries, of whom 1765 were adults and 3764 were children. Thirty percent (n=1662) of all bicycle injuries involved motor vehicles, although the rate of injuries resulting in hospitalization was 37% among adults and 27% among children. Injury characteristics and hospital resource utilization differed substantially by age group. Cyclists struck by a motor vehicle presented with more severe injuries requiring more hospital resources and resulting in poorer outcomes than those not involved with motor vehicles. The interaction effect between motor vehicle involvement and age was significant for torso injuries and need for medical imaging. We found that injury characteristics, hospital resource utilization and health-related outcomes for bicycle injuries are highly dependent on patient's age and mechanism of injury. Effect modification of motor vehicle involvement by age may in part reflect physicians' attitudes toward pediatric imaging. The risks identified in this study should be used for preparedness and management of trauma hospitalizations from bicycle injuries. PMID:22062347

  8. Preparation of polydimethylsiloxane/beta-cyclodextrin/divinylbenzene coated "dumbbell-shaped" stir bar and its application to the analysis of polycyclic aromatic hydrocarbons and polycyclic aromatic sulfur heterocycles compounds in lake water and soil by high performance liquid chromatography.

    Science.gov (United States)

    Yu, Chunhe; Yao, Zhimin; Hu, Bin

    2009-05-01

    A "dumbbell-shaped" stir bar was proposed to prevent the friction loss of coating during the stirring process, and thus prolonged the lifetime of stir bars. The effects of the coating components, including polydimethylsiloxane (PDMS), beta-cyclodextrin (beta-CD) and divinylbenzene (DVB) were investigated according to an orthogonal experimental design, using three polycyclic aromatic hydrocarbons (PAHs) and four polycyclic aromatic sulfur heterocycles (PASHs) as model analytes. Four kinds of stir bars coated with PDMS, PDMS/beta-CD, PDMS/DVB and PDMS/beta-CD/DVB were prepared and their extraction efficiencies for the target compounds were compared. It was demonstrated that PDMS/beta-CD/DVB-coated stir bar showed the best affinity to the studied compounds. The preparation reproducibility of PDMS/beta-CD/DVB-coated stir bar ranged from 3.2% to 15.2% (n = 6) in one batch, and 5.2% to 13.4% (n = 6) among batches. The "dumbbell-shaped" stir bar could be used for about 40 times, which were 10 extractions more than a normal stir bar. The prepared PDMS/beta-CD/DVB-coated "dumbbell-shaped" stir bar was used for stir bar sorptive extraction (SBSE) of PAHs and PASHs and the desorbed solution was introduced into HPLC-UV for subsequent analysis. The limits of detection of the proposed method for seven target analytes ranged from 0.007 to 0.103 microg L(-1), the relative standard deviations were in the range of 6.3-12.9% (n = 6, c = 40 microg L(-1)), and the enrichment factors were 19-86. The proposed method was successfully applied to the analysis of seven target analytes in lake water and soil samples.

  9. Chest Traumas due to Bicycle accident in Childhood

    Directory of Open Access Journals (Sweden)

    Ufuk Cobanoglu

    2011-09-01

    Full Text Available Aim:Childhood injuries are the leading cause of death in children and result in significant healthcare utilization. Trauma is the second most common cause of mortality in children aged 1-4 years and leading cause of death in children older than 4 years. Thoracic injury is the second most leading cause of death in traumatized children. Multisystemic injury is found in more than 50% of children with thoracic injuries most of which are secondary to blunt traumas. We planned this study to evaluate thorax trauma cases secondary to bicycle driving in childhood and to draw attention to the importance of the regulation of traffic rules, the education of bicycle drivers.Material and Methods:  A retrospective evaluation was performed in 17 pediatric patients admitted to the Department of Thoracic Surgery during 2006-2010 with a diagnosis of chest trauma due to bicycle driving. For every patient, a pediatric trauma score (PTS was calculated. Descriptive statistics were performed for PTS. Results; Eleven (64.70% cases were injured due to the tricycle accidents and six cases 6 (35.29% were injured due to the two-wheeled bicycle accidents. The most frequent thoracic pathologies included pulmonary contusion (41.2% and chest wall contusion (29.41%. Extrathoracic injuries were seen in 35.29%, the extremities (17.64% and abdomino pelvic (11.76% being the most commonly involved. Treatment consisted of symptomatic treatment in 12 patients (70.58%, tube thoracostomy in 2 patients (11.76%, and thoracotomy in 1 patient (5.9%. The morbidity was seen in 3 patients (17.64%. The mortality rate was 5.9% (n:1. The mean PTS of the cases who had additional system injuries were significantly worse than the cases who had isolated chest traumas Conclusions: The pediatric thorax has a greater cartilage content and incomplete ossification of the ribs. Due to the pliability of the pediatric rib cage and mediastinal mobility, significant intrathoracic injury may exist in the

  10. Personal and behavioral factors associated with bicycling in adults from Curitiba, Parana State, Brazil

    Directory of Open Access Journals (Sweden)

    Marilson Kienteka

    2014-01-01

    Full Text Available Bicycling is an important form of physical activity that can promote health benefits. The objective of this study was to analyze the association between personal and behavioral aspects in transportation bicycling and leisure time bicycling in adults. Data was drawn from a household survey involving 677 adults (53.1% female in Curitiba, Paraná State, Brazil. The prevalence of bicycling was 11.2% for transportation and 16.7% for leisure. The frequency of leisure time bicycling was higher among men (PR = 2.08; p < 0.001, young people < 30 and adults aged between 30 and 39.9, bicycle owners (PR = 8.76; p < 0.001 and among the physically active. Transportation bicycling occurred more frequently among men (PR = 3.63; p < 0.001, individuals aged 30 to 39.9, those with a low socioeconomic status (PR = 5.00; p = 0.006, bicycle owners (PR = 10.2; p < 0.001 and individuals with a negative perception of their quality of life. The prevalence of bicycling is low in Curitiba considering its potential as a means of physical activity. Personal and behavioral factors were associated with each form of bicycling.

  11. The fastest bicycle in the world; how a team of Delft students is building a bicycle to break the world speed record

    NARCIS (Netherlands)

    Annega, G.

    2011-01-01

    The Netherlands is a country known for its extensive use of bicycles as a means of everyday transport. However, while it has existed for about two centuries, todays bicycles only differ from those of the 19th century in relatively small details. Human Power Team Delft is building a whole new type of

  12. Mutagenic Potency of Food-Derived Heterocyclic Amines

    Energy Technology Data Exchange (ETDEWEB)

    Felton, J S; Knize, M G; Wu, R W; Colvin, M E; Hatch, F T; Malfatti, M A

    2006-10-26

    The understanding of mutagenic potency has been primarily approached using ''quantitative structure activity relationships'' (QSAR). Often this method allows the prediction of mutagenic potency of the compound based on its structure. But it does not give the underlying reason why the mutagenic activities differ. We have taken a set of heterocyclic amine structures and used molecular dynamic calculations to dock these molecules into the active site of a computational model of the cytochrome P-450 1A1 enzyme. The calculated binding strength using Boltzman distribution constants was then compared to the QSAR value (HF/6-31G* optimized structures) and the Ames/Salmonella mutagenic potency. Further understanding will only come from knowing the complete set of mutagenic determinants. These include the nitrenium ion half-life, DNA adduct half-life, efficiency of repair of the adduct, and ultimately fixation of the mutation through cellular processes. For two isomers, PhIP and 3-Me-PhIP, we showed that for the 100-fold difference in the mutagenic potency a 5-fold difference can be accounted for by differences in the P450 oxidation. The other factor of 20 is not clearly understood but is downstream from the oxidation step. The application of QSAR (chemical characteristics) to biological principles related to mutagenesis is explored in this report.

  13. Efficiency of Choice Set Generation Methods for Bicycle Routes

    DEFF Research Database (Denmark)

    Halldórsdóttir, Katrín; Rieser-Schüssler, Nadine; W. Axhausen, Kay;

    With a growing interest in sustainable transport systems, the interest has increased on encouraging more cycling. To encourage cycling, it is important to identify which network attributes influence cyclists route choice and evaluate the trade-offs among these attributes. To analyse travel...... behaviour, observed choices and alternatives composing the choice set of each cyclist are necessary. However, generating the alternative choice sets can prove challenging. This paper analyses the efficiency of various choice set generation methods for bicycle routes in order to contribute to our...... that might produce inconsistent estimates. There have been some studies on bicycle route choice set generation reported in the literature, whereof few studies focussed on route choice models for bicyclist estimated from GPS observations. Menghini et al. [3] successfully applied a Breadth First Search on Link...

  14. [Electrically assisted bicycles: health enhancement or "green" gadget?].

    Science.gov (United States)

    Welker, J; Cornuz, J; Gojanovic, B

    2012-07-25

    Electrically assisted bicycles (EAB) are flourishing in cities throughout the world and capitalize on ecological and practical advantages, helping in the fight against pollution, CO2 emissions and traffic jam. Human power is necessary to activate the electrical support, so that it equals to a moderate intensity physical activity (> 3 MET), or a vigorous one on hilly courses (>6 MET). The ecological benefits are obvious and transportation departments tend to support citizens who purchase one. EAB offer increased mobility at speeds of 15 to 25 km/h depending on hills and fitness of the rider, but could cause more accidents. EAB is linked to a real physical activity beneficial for health, but potentially more dangerous than a traditional bicycle. PMID:22913003

  15. A system for quantifying the cooling effectiveness of bicycle helmets.

    Science.gov (United States)

    Reid, J; Wang, E L

    2000-08-01

    This article describes the design and development of a system that is capable of quantifying the thermal comfort of bicycle helmets. The motivation for the development of the system stems from the desire both to increase helmet use and to provide the designer with a quantitative method of evaluating the thermal comfort of a helmet. The system consists of a heated mannequin head form, a heated reference sphere, a small wind tunnel, and a data acquisition system. Both the head form and the reference sphere were instrumented with thermocouples. The system is capable of simulating riding speeds ranging from 4.5-15.5 m/s. A cooling effectiveness, C1, that is independent of both ambient conditions and wind velocity is defined as a measure of how well the helmet ventilates as compared to the reference sphere. The system was validated by testing six commercially available bicycle helmets manufactured between approximately 1992 and 1998. PMID:11036573

  16. Cellular automata simulation of traffic including cars and bicycles

    Science.gov (United States)

    Vasic, Jelena; Ruskin, Heather J.

    2012-04-01

    As 'greening' of all aspects of human activity becomes mainstream, transportation science is also increasingly focused around sustainability. Modal co-existence between motorised and non-motorised traffic on urban networks is, in this context, of particular interest for traffic flow modelling. The main modelling problems here are posed by the heterogeneity of vehicles, including size and dynamics, and by the complex interactions at intersections. Herein we address these with a novel technique, based on one-dimensional cellular automata components, for modelling network infrastructure and its occupancy by vehicles. We use this modelling approach, together with a corresponding vehicle behaviour model, to simulate combined car and bicycle traffic for two elemental scenarios-examples of components that would be used in the building of an arbitrary network. Results of simulations performed on these scenarios, (i) a stretch of road and (ii) an intersection causing conflict between cars and bicycles sharing a lane, are presented and analysed.

  17. Computational design of fused heterocyclic energetic materials

    Science.gov (United States)

    Tsyshevskiy, Roman; Pagoria, Philip; Batyrev, Iskander; Kuklja, Maija

    A continuous traditional search for effective energetic materials is often based on a trial and error approach. Understanding of fundamental correlations between the structure and sensitivity of the materials remains the main challenge for design of novel energetics due to the complexity of the behavior of energetic materials. State of the art methods of computational chemistry and solid state physics open new compelling opportunities in simulating and predicting a response of the energetic material to various external stimuli. Hence, theoretical and computational studies can be effectively used not only for an interpretation of sensitivity mechanisms of widely used explosives, but also for identifying criteria for material design prior to its synthesis and experimental characterization. We report here, how knowledge on thermal stability of recently synthesized materials of LLM series is used for design of novel fused heterocyclic energetic materials, including DNBTT (2,7-dinitro-4H,9H-bis([1, 2, 4"]triazolo)[1,5-b:1',5'-e][1, 2, 4, 5]tetrazine), compound with high thermal stability, which is on par or better than that of TATB. This research is supported by ONR (Grant N00014-12-1-0529), NSF XSEDE resources (Grant DMR-130077) and DOE NERSC resources (Contract DE-AC02-05CH11231).

  18. Heterocyclic amines in meat and meat products

    Directory of Open Access Journals (Sweden)

    Aliye BULGAN

    2013-06-01

    Full Text Available Heterocyclic amines (HA are the mutagenic/carcinogenic compounds which generate as a result of cooking of red meat, poultry meat and fish fillets at high temperatures. Up to 20 different HAs were detected and classified in the researches that conducted on these types of meats cooked at high temperatures. HAs are the products of Maillard reactions and the Strecker degredation of main precursors such as creatine/creatinine, aminoacid and the polysaccharides. Many physical and chemical factors effect the formation of HAs. Thus, it was reported by many researchers that utilizing coating and marination processes in addition to using natural and synthetic antioxidants and seasonings-plant extracts were effective on inhibiting/decreasing the formation of HAs. Additionally, boiling/steaming and microwave cooking methodologies were recommended instead of barbecuing, grilling or frying to inhibit/decrease the formation of HAs. The HAs formed in meat and meat products and the factors which have effects on the formation of HAs are presented in this review.

  19. Optimization of electric bicycle for youths with disabilities

    OpenAIRE

    Blumenstein, Tobias; Zeitlmann, Hilar; Alves-Pinto, Ana; Turova, Varvara; Lampe, Renée

    2014-01-01

    Cerebral palsy is a group of neurodevelopmental disorders that affect a person’s ability to move and to maintain balance and posture. People with cerebral palsy have also perception and space orientation deficits so that special assistance devices should be developed to compensate these handicaps. The objective was to optimize an adapted electric bicycle (E-bike) for youths with neurodevelopmental disorders. An adapted E-bike was provided with ultrasonic sensors that measure distances to obje...

  20. Interventions in Bicycle Infrastructure, Lessons from Dutch and Danish Cases

    OpenAIRE

    Van Goeverden, K.; Nielsen, Thomas Alexander Sick; Harder, Henrik; van Nes, Rob

    2015-01-01

    Today the interest in cycling is increasing worldwide and in many countries authorities are faced with the question how cycling can be promoted efficiently. In the Netherlands and Denmark, this question came up already in the 1970s when the downsides of the rapidly increasing motorisation became evident. At the time, in both countries large scale interventions in bicycle infrastructure were introduced and evaluated extensively in order to create knowledge on efficient promoting of cycling in ...

  1. Methodology for a global bicycle real world accidents reconstruction

    OpenAIRE

    Bourdet, Nicolas; Deck, Caroline; Serre, Thierry; Perrin, Christophe; LLARI, Maxime; Willinger, Rémy

    2012-01-01

    The use of the bicycle on a large scale encouraged in the context to develop an eco friendly environment is facing today on a range of barriers. One of these barriers identified by researchers and governments is observed to include ‘road safety’. Hence, it is necessary to set up a protection system for bicyclists especially for the cephalic segment. Currently only few studies are available concerning the head impact loading in case of real accidents. Therefore, the objective of th...

  2. In-depth real-world bicycle accident reconstructions

    OpenAIRE

    Bourdet, Nicolas; Deck, Caroline; Serre, Thierry; Perrin, Christophe; LLARI, Maxime; Willinger, Rémy

    2013-01-01

    Use of bicycles on a large scale, encouraged in the context to develop an eco-friendly environment, is facing today a range of barriers. One of these barriers identified by researchers and governments is observed to include ‘road safety’. Hence, it is necessary to set up a protection system for bicyclists especially for the cephalic segment. Currently only few studies are available concerning the head impact loading in case of real accidents. Therefore, the objective of this work ...

  3. The value of time and external benefits in bicycle appraisal

    OpenAIRE

    Börjesson, Maria; ELIASSON, Jonas

    2011-01-01

    We estimate the value of time savings, different cycling environments and additional benefits in cost-benefit analysis of cycling investments. Cyclists’ value of travel time savings turns out to be high, considerably higher than the value of time savings on alternative modes. Cyclists also value other improvements highly, such as separated bicycle lanes. As to additional benefits of cycling improvements in the form of health and reduced car traffic, our results do not support the notion that ...

  4. Harvesting Energy from the Counterbalancing (Weaving) Movement in Bicycle Riding

    OpenAIRE

    Shashank Priya; Jeongjin Yeo; Yoonseok Yang

    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 p...

  5. Finite element analysis of advanced bicycle precision brake disk forming technology

    Directory of Open Access Journals (Sweden)

    Chen Dyi-Cheng

    2015-01-01

    Full Text Available In recent years, the bicycle has become an environmentally friendly transportation. The bicycle can be divided into mountain bicycle and highway bicycle. Safe driving is the prior consideration. The bicycle braking system can be divided into oil pressure disk brakes and mechanical disk brakes. The brake disk system is one indispensable component of the safe system. In accordance to overall weight consideration of the bike, the brake disk should also focus on the lightweight design. This paper discussed an innovative brake disk forming technology for 6061 aluminum alloy by the rigid-plastic finite element analysis. The simulation parameters include geometric shapes of the brake disk and mold, die temperature, and friction factors. The stress and strain in forming, brake deformation and vibration modal analysis of brake disk in riding were studied. The paper is expected to offer some precision bicycle brake disk manufacture knowledge for industry.

  6. 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. PMID:23112598

  7. 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.

  8. [Mortality due to bicycle accidents in Pernambuco, Brazil].

    Science.gov (United States)

    Galvão, Pauliana Valéria Machado; Pestana, Luciana Pinto; Pestana, Valter Mário; Spíndola, Michelline Oliveira Pedrosa; Campello, Reginaldo Inojosa Carneiro; de Souza, Eliane Helena Alvim

    2013-05-01

    The scope of this paper was to conduct a quantitative analysis of deaths resulting from bicycle accidents in the state of Pernambuco by studying secondary data between 2001 and 2010. The sample consisted of all the Deaths recorded in the Mortality Information System of the Unified Health System Database that reported bicycle accidents between 2001 and 2010. Descriptive measures were determined for all variables. Socio-demographic variables were paired with the basic cause of death in order to find a statistical correlation. In Pernambuco, the aforementioned information system recorded 517 deaths resulting from bicycle accidents, with greater frequency in men between 25 and 59 years of age, Afro-Brazilians, single and of unknown schooling. The mean age was 36.82 years (SD = 17.026), and the minimum and maximum age of 4 and 86 years old, respectively. The findings highlight the need for the creation of adequate infrastructure and effective legal measures to prevent traffic accidents involving this type of vehicle, relying on the evidence of distribution of cases in most Pernambuco municipalities.

  9. Recent advances in the electrochemical construction of heterocycles

    Directory of Open Access Journals (Sweden)

    Robert Francke

    2014-12-01

    Full Text Available Due to the fact that the major portion of pharmaceuticals and agrochemicals contains heterocyclic units and since the overall number of commercially used heterocyclic compounds is steadily growing, heterocyclic chemistry remains in the focus of the synthetic community. Enormous efforts have been made in the last decades in order to render the production of such compounds more selective and efficient. However, most of the conventional methods for the construction of heterocyclic cores still involve the use of strong acids or bases, the operation at elevated temperatures and/or the use of expensive catalysts and reagents. In this regard, electrosynthesis can provide a milder and more environmentally benign alternative. In fact, numerous examples for the electrochemical construction of heterocycles have been reported in recent years. These cases demonstrate that ring formation can be achieved efficiently under ambient conditions without the use of additional reagents. In order to account for the recent developments in this field, a selection of representative reactions is presented and discussed in this review.

  10. Conversion Of An Ordinary N Bicycle Into An Electric Bike And Related Research

    OpenAIRE

    Marius Janavičius

    2014-01-01

    An electric bicycle as a transport and leisure vehicle is expected to have a promising future. Currently, he market offers a great choice of factory electric bicycles and conversion kits to remake an ordinary bicycle into an electric bike. Also, the increasing number of electric vehicles is determined by the reduction in costs for manufacturing of batteries and an evolution in battery technology. This article presents the implementation of an electric bike by selecting the “Golden Motor Techn...

  11. A Modified Cellular Automaton Approach for Mixed Bicycle Traffic Flow Modeling

    OpenAIRE

    Xiaonian Shan; Zhibin Li; Xiaohong Chen; Jianhong Ye

    2015-01-01

    Several previous studies have used the Cellular Automaton (CA) for the modeling of bicycle traffic flow. However, previous CA models have several limitations, resulting in differences between the simulated and the observed traffic flow features. The primary objective of this study is to propose a modified CA model for simulating the characteristics of mixed bicycle traffic flow. Field data were collected on physically separated bicycle path in Shanghai, China, and were used to calibrate the C...

  12. "The Mechanisms. Light and Miraculous": The Convivial Bicycle in Literature and Film

    OpenAIRE

    Guevara, J. Josh

    2012-01-01

    This dissertation explores the prevalent representation of the bicycle as a liberatory figure in theoretical texts, novels, films, and poetry. Because the bicycle confers unexpected creativity and autonomy, it alters definitions of technology, modernity, and identity. Chapter one recuperates and employs Ivan Illich's concept of conviviality in order to re-examine the inheritance of the project of modernity and question the definition of technology in the twenty-first century bicycle epoch. Fo...

  13. Automated Analysis Methods for the Assessment of Bicycle Infrastructure and Demand

    OpenAIRE

    Pashkevich, Anton

    2013-01-01

    A first phase of the research activity has been related to the study of the state of art of the infrastructures for cycling, bicycle use and methods for evaluation. In this part, the candidate has studied the "bicycle system" in countries with high bicycle use and in particular in the Netherlands. Has been carried out an evaluation of the questionnaires of the survey conducted within the European project BICY on mobility in general in 13 cities of the participating countries. The questionn...

  14. Blue Chitin columns for the extraction of heterocyclic amines from urine samples

    DEFF Research Database (Denmark)

    Bang, J.; Frandsen, Henrik Lauritz; Skog, K.

    2004-01-01

    . Blue Chitin columns were used for the extraction and purification of heterocyclic amines from urine samples spiked with 14 different heterocyclic amines. The samples were analysed using LC-MS. The results show that Blue Chitin columns provide a straightforward and rapid means of extracting heterocyclic...... amines from urine samples, and that Blue Chitin column are also useful in the purification of urinary metabolites....

  15. Compositions comprising a polypeptide having cellulolytic enhancing activity and a bicyclic compound and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Quinlan, Jason; Xu, Feng; Sweeney, Matthew

    2016-10-04

    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a bicyclic compound. The present invention also relates to methods of using the compositions.

  16. Compositions comprising a polypeptide having cellulolytic enhancing activity and a bicycle compound and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Feng; Sweeney, Matthew; Quinlan, Jason

    2015-06-16

    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a bicyclic compound. The present invention also relates to methods of using the compositions.

  17. Mutagenic activity and heterocyclic amine content of the human diet

    Energy Technology Data Exchange (ETDEWEB)

    Knize, M.G.; Dolbeare, F.A.; Cunningham, P.L.; Felton, J.S.

    1993-01-15

    The mutagenic activity and the mass amount of heterocyclic amines responsible for the mutagenic activity have been measured in some cooked foods. Cooked meats are the predominant source of mutagenic activity in the diet with values ranging from 0 to 10,000 revertants per gram reported in the Ames/Salmonelia test with strain TA98. Several heterocyclic amines are present and have been quantified using solid-phase extraction followed by HPLC. Frying at higher temperatures and for longer times produces the greatest mutagenic response, and concomitantly, the largest amounts of heterocyclic amines. Most of the mutagenic activity in fried meat samples can be accounted for by MelQx, DiMelQx and IQ, although other heterocylic amines are present and PHIP mutagenic activity becomes significant at higher temperatures. Non-meat products such as baked breads can also form significant mutagenic activity, particularly when overcooked. Commercially prepared hamburgers made from meat substitutes such as tofu, wheat gluten or tempeh and fried at 210{degrees}C have up to 10% of the mutagenic activity of a fried beef patty cooked under the same conditions. When detected, amounts of heterocyclic amines in fried beef patties range from a total of 0.35 ng/g for commercial beef hamburgers to 142 ng/g for a beef patty cooked over a barbecue. Dietary intake is expected to have a large range, from less than one microgram per day to over 50 micrograms per day based on current knowledge of known heterocyclic amine chemicals and heterocyclic amine-containing foods.

  18. Including Accident Information in Automatic Bicycle Route Planning for Urban Areas

    Directory of Open Access Journals (Sweden)

    Alex D. Singleton

    2011-01-01

    Full Text Available Between 2005 and 2007 there were 9071 traffic accidents involving bicycles within London and this paper demonstrates the utility of Geographic Information Systems as a tool for analysing and visualising these occurrences. Through linkage of these spatial locations to a street network dataset it was possible to create a variety of intelligence about the types of street infrastructure where accidents predominantly occur. Additionally, a network routing algorithm was adapted to account for the frequency of accidents within a series of proposed journeys. This pilot routing application compared the quickest route with an accident avoidance weighted route between a series of origins and destinations. The results demonstrated that the routes avoiding areas of high accident volume did not increase journey length significantly; however they did provide a “safer” route based on empirical evidence over the volume of accident locations.

  19. Thermoregulation during prolonged actual and laboratory-simulated bicycling.

    Science.gov (United States)

    Brown, S L; Banister, E W

    1985-01-01

    Thermoregulatory and cardiorespiratory responses to bicycling 55 km (mean speed 9.7 m X s-1) outdoors (15 degrees C DB) were compared to equivalent cycle ergometry (90 min at 65% VO2max) in the laboratory (20-23 degrees C DB, 50% RH) in 7 trained cyclists. Outdoor environmental conditions were simulated with fans and lamps, and were contrasted with standard no-wind, no-sun laboratory conditions. Sweating rate was similar during outdoor and laboratory simulated outdoor cycling (0.90 and 0.87 to 0.94 1 X h-1 respectively). During outdoor bicycling, mean heart rate (161 bt X min-1) was 7-13% higher (p less than .05) than under laboratory conditions, suggesting a greater strain for a similar external work rate. The increase in rectal temperature (0.8 degrees C) was 33-50% less (p less than 0.05) at the cooler outdoor ambient temperature than in the laboratory. Thermoregulatory stress was greater under the no-fan, no-lamp laboratory condition than during simulated outdoor conditions (36-38% greater (p less than 0.05) sweating rate, 15-18% greater (p less than 0.01) mean skin temperature, 6.4 to 7.8 fold greater (p less than 0.01) amount of clothing-retrained sweat). The cooling wind encountered in actual road bicycling apparently reduces thermoregulatory and circulatory demands compared with stationary cycle ergometry indoors. Failure to account for this enhanced cooling may result in overestimation of the physiological stress of actual road cycling.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Safety effects of permanent running lights for bicycles: A controlled experiment.

    Science.gov (United States)

    Madsen, J C O; Andersen, T; Lahrmann, H S

    2013-01-01

    Making the use of daytime running lights mandatory for motor vehicles is generally documented to have had a positive impact upon traffic safety. Improving traffic safety for bicyclists is a focal point in the road traffic safety work in Denmark. In 2004 and 2005 a controlled experiment including 3845 cyclists was carried out in Odense, Denmark in order to examine, if permanent running lights mounted to bicycles would improve traffic safety for cyclists. The permanent running lights were mounted to 1845 bicycles and the accident rate was recorded through 12 months for this treatment group and 2000 other bicyclists, the latter serving as a control group without bicycle running lights. The safety effect of the running lights is analysed by comparing incidence rates - number of bicycle accidents recorded per man-month - for the treatment group and the control group. The incidence rate, including all recorded bicycle accidents with personal injury to the participating cyclist, is 19% lower for cyclists with permanent running lights mounted; indicating that the permanent bicycle running light significantly improves traffic safety for cyclists. The study shows that use of permanent bicycle running lights reduces the occurrence of multiparty accidents involving cyclists significantly. In the study the bicycle accidents were recorded trough self-reporting on the Internet. Possible shortcomings and problems related to this accident recording are discussed and analysed. PMID:22884376

  1. Advocating Green Transport and Promoting Healthy Urban Development: Strategies for Bicycle Transport Development in Jinan

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>As a green transport means,the bicycle has a history of over two hundred years.Since the 1970s,due to the inf luence of energy crisis and the consciousness of environment protection,the bicycle has regained its popularity in the public for its

  2. Use of Adapted Bicycles on the Learning of Conventional Cycling by Children with Mental Retardation

    Science.gov (United States)

    Burt, Tammy L.; Porretta, David L.; Klein, Richard E.

    2007-01-01

    This study investigated the use of adapted bicycles on the acquisition, maintenance, and generalization of conventional cycling by seven children with mild mental retardation. Feedback was used in addition to the adapted bicycles and consisted of pedal rate, head position, and steering participation. A multiple probe design was used. Participants…

  3. 16 CFR Figure 8 to Part 1512 - Reflectorized Bicycle Wheel Rim Abrasion Test Device

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Reflectorized Bicycle Wheel Rim Abrasion Test Device 8 Figure 8 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL...—Reflectorized Bicycle Wheel Rim Abrasion Test Device EC03OC91.074...

  4. 77 FR 12761 - Special Regulations; Areas of the National Park System, Saguaro National Park, Bicycle Route

    Science.gov (United States)

    2012-03-02

    ...The National Park Service (NPS) is proposing to designate the Hope Camp Trail as a bicycle route within Saguaro National Park (Park). The National Park Service general regulation at 36 CFR 4.30(b) requires promulgation of a special regulation to designate bicycle routes outside of developed areas and special use...

  5. [A specific sign of the injury inflicted by the front wheel of a bicycle].

    Science.gov (United States)

    Leonov, S V; Pinchuk, P V; Molchanov, D V

    2016-01-01

    The authors report the results of the comprehensive forensic medical expertise of the injury inflicted by the front wheel of a bicycle that revealed a new specific sign of the contact between the protruding part of the wheel of the bicycle (the brake disk) and the pedestrian's body. PMID:27070037

  6. The unexpected stable market share of the bicycle in The Netherlands

    NARCIS (Netherlands)

    Van Goeverden, C.D.; Van Arem, B.; Godefrooij, T.

    2013-01-01

    In the Netherlands, the share of the bicycle as the main mode in all person trips has been highly constant in the past three decades (about 27%). A constant share is remarkable because a number of developments in this period were unfavourable for bicycle use, like ageing of the population, growing n

  7. Bicycle Design: A different approach to improving on the world human powered speed records

    NARCIS (Netherlands)

    Epema, H.K.; Van den Brand, S.; Gregoor, W.; Kooijman, J.D.G.; Pereboom, H.P.; Wielemaker, D.C.; Van der Zweep, C.J.

    2012-01-01

    The current International Human Powered Vehicle Association world records for faired bicycles stand at 133.284km/h for the 200m flying start speed record and 91.562 km for the hour record. Traditionally the recumbent bicycles that have been developed for breaking one of either of these records have

  8. Does pedalling on a recumbent bicycle influence the cyclist’s steering behaviour?

    NARCIS (Netherlands)

    Boon, K.M.; Klap, P.; Van Lanen, J.A.; Letsoin, G.J.; Jansen, A.J.

    2014-01-01

    The paper presents the answer to the question how pedalling on a specific recumbent bicycle, such as the VeloX3, influences a cyclist’s ability to steer the bicycle. The research aims to find the correlation between pedalling and the undesired steering movements it creates. To test this assumption a

  9. Getting Bicycles on Trains - Inter-modal Transport Developments in Denmark

    DEFF Research Database (Denmark)

    Jørgensen, Ulrik; Pedersen, Bjørn Brix

    2001-01-01

    The combined use of bicycles and trains has been favored in contemporary public transport policies in Denmark. Although bicycling has played a major role in Danish personal transportation in more than hundred years, the attitude from public transport authorities towards supporting bicyclists has...

  10. The Dutch Reference Study: Cases of interventions in bicycle infrastructure reviewed in the framework of Bikeability

    NARCIS (Netherlands)

    Van Goeverden, C.D.; Godefrooij, T.

    2011-01-01

    The Netherlands have a tradition of high bicycle usage and a long history of research on effective policies for promoting cycling. Findings in Dutch studies can be useful in the Danish Bikeability-project that has the objective to increase the level of knowledge in relation to bicycle based transpor

  11. Solid-phase synthesis of complex and pharmacologically interesting heterocycles

    DEFF Research Database (Denmark)

    Nielsen, Thomas Eiland

    2009-01-01

    Efficient routes for the creation of heterocycles continue to be one of the primary goals for solid-phase synthesis. Recent advances in this field rely most notably on transition-metal-catalysis and N-acyliminium chemistry to mediate a range of cyclization processes for the generation of compounds...

  12. Greener and Expeditious Synthesis of Bioactive Heterocycles using Microwave Irradiation

    Science.gov (United States)

    The utilization of green chemistry techniques is dramatically reducing chemical waste and reaction times as has recently been proven in several organic syntheses and chemical transformations. To illustrate these advantages in the synthesis of bio-active heterocycles, we have stud...

  13. Synthesis and Anion Recognition of a Novel Heterocyclic Organotin Complex

    Institute of Scientific and Technical Information of China (English)

    Li Xin ZHANG; Gui Zhi LI; Zhi Qiang LI

    2004-01-01

    A novel heterocyclic hexacoordinate organotin(IV) complex, bis(O-vanillin)-semi ethylenediamino dibenzyltin (VEDBT) was synthesized by the reaction of dibenzyltin dichloride with bis(O-vanillin)-semiethyenediamine, its structure has been characterized by spectral methods.The electrodes using VEDBT as a neutral carrier show high selectivity for salicylate anions.

  14. Solvent-Free Synthesis of Heterocyclic Compounds Using Microwave Technology

    Science.gov (United States)

    Ahmad, Natiq Ghanim

    The synthesis of heterocyclic compounds containing pyrimidine, pyrazoline, isoxazoline and cyclohexanone ring from chalcone derivatives containing 3,4-dimethoxyphenyl group and furfuryl ring group under dry condition using microwaves. The structures of these compounds were confirmed by IR, H1 NMR and physical constants.

  15. Greener Synthetic Alternatives to Heterocycles, Nanomaterials and Nanocomposites

    Science.gov (United States)

    Microwave (MW) expedited reaction of neat reactants or catalyzed by mineral support surfaces, such as alumina, silica, clay, or their ‘doped’ versions, for the rapid one-pot assembly of heterocyclic compounds from in situ generated reactive intermediates via enamines or using hyp...

  16. Skeletal diversification via heteroatom linkage control: preparation of bicyclic and spirocyclic scaffolds from N-substituted homopropargyl alcohols.

    Science.gov (United States)

    Painter, Thomas O; Bunn, Jonathon R; Schoenen, Frank J; Douglas, Justin T; Day, Victor W; Santini, Conrad

    2013-04-19

    The discovery and application of a new branching pathway synthesis strategy that rapidly produces skeletally diverse scaffolds is described. Two different scaffold types, one a bicyclic iodo-vinylidene tertiary amine/tertiary alcohol and the other, a spirocyclic 3-furanone, are each obtained using a two-step sequence featuring a common first step. Both scaffold types lead to intermediates that can be orthogonally diversified using the same final components. One of the scaffold types was obtained in sufficiently high yield that it was immediately used to produce a 97-compound library.

  17. Can You Ride a Bicycle? The Ability to Ride a Bicycle Prevents Reduced Social Function in Older Adults With Mobility Limitation

    Directory of Open Access Journals (Sweden)

    Ryota Sakura

    2016-06-01

    Full Text Available Background: The health benefits of bicycling in older adults with mobility limitation (ML are unclear. We investigated ML and functional capacity of older cyclists by evaluating their instrumental activities of daily living (IADL, intellectual activity, and social function. Methods: On the basis of interviews, 614 community-dwelling older adults (after excluding 63 participants who never cycled were classified as cyclists with ML, cyclists without ML, non-cyclists with ML (who ceased bicycling due to physical difficulties, or non-cyclists without ML (who ceased bicycling for other reasons. A cyclist was defined as a person who cycled at least a few times per month, and ML was defined as difficulty walking 1 km or climbing stairs without using a handrail. Functional capacity and physical ability were evaluated by standardized tests. Results: Regular cycling was documented in 399 participants, and 74 of them (18.5% had ML; among non-cyclists, 49 had ML, and 166 did not. Logistic regression analysis for evaluating the relationship between bicycling and functional capacity revealed that non-cyclists with ML were more likely to have reduced IADL and social function compared to cyclists with ML. However, logistic regression analysis also revealed that the risk of bicycle-related falls was significantly associated with ML among older cyclists. Conclusions: The ability and opportunity to bicycle may prevent reduced IADL and social function in older adults with ML, although older adults with ML have a higher risk of falls during bicycling. It is important to develop a safe environment for bicycling for older adults.

  18. Vision-Based Bicycle Detection Using Multiscale Block Local Binary Pattern

    Directory of Open Access Journals (Sweden)

    Hongyu Hu

    2014-01-01

    Full Text Available Bicycle traffic has heavy proportion among all travel modes in some developing countries, which is crucial for urban traffic control and management as well as facility design. This paper proposes a real-time multiple bicycle detection algorithm based on video. At first, an effective feature called multiscale block local binary pattern (MBLBP is extracted for representing the moving object, which is a well-classified feature to distinguish between bicycles and nonbicycles; then, a cascaded bicycle classifier trained by AdaBoost algorithm is proposed, which has a good computation efficiency. Finally, the method is tested with video sequence captured from the real-world traffic scenario. The bicycles in the test scenario are successfully detected.

  19. Bicycle Riding: Impact on Lower Urinary Tract Symptoms and Erectile Function in Healthy Men

    Science.gov (United States)

    Baek, Seok; Lee, Sun Young; Kim, Jong Min; Shin, Esther; Kam, Sin

    2011-01-01

    Purpose Recently, reports in the mass media have implicated that bicycle riding increases the risk of erectile dysfunction and prostatic diseases. So, we evaluate the impact of bicycle riding on erectile function and lower urinary tract symptoms (LUTS) in healthy general men. Methods From 26 June 2010 to 20 July 2010, we investigate degree of LUTS (voiding and storage symptoms), using International Continence Society-male Questionnaire (ICS-mQ) and erectile function using International Index of Erectile Function-5 Questionnaire (IIEF-5) in 5 work places (personnel of public office, hospital, university, etc.) of which bicycle riding club members were doing active club activities. Respondents, who participated in club activities for 6 months and longer, were classified as the bicycle club (142 men; age, 44.02±8.56). Ones who do not ride bicycles were classified as the control group (83 men; age, 42.13±7.85). People who were having the history of urological and other chronic diseases (diabetes, vascular disease, heart disease, etc) were excluded from both groups. Results Bicycle club is not significantly associated with increased prevalence of LUTS (bicycle club, 2.1 to 57.7% control, 4.8 to 73.5%) and erectile dysfunction (bicycle club, 46.1% control, 55.4%). The total mean score (storage/voiding/erectile function) of bicycle club (13.93±1.95/11.14±3.49/20.46±5.30) were not significantly different from control (14.35±2.49/11.52±3.38/20.40±4.07) (P=0.190 to 0.968). Conclusions These results suggested that bicycle riding as exercise or hobby has no negative effect on LUTS and erectile function in healthy general men, although this research data were limited to the questionnaire analysis. PMID:21811700

  20. The influence of body mass in endurance bicycling.

    Science.gov (United States)

    Swain, D P

    1994-01-01

    Bicycling is a complex sport in which an athlete's energy cost is related to two principal forces: air resistance when traveling on flat terrain, and gravity when traveling uphill. Both wind tunnel data and physiological measurements suggest that air resistance scales as body mass to about the 1/3 power. Thus, large cyclists have only slightly greater frontal drags than small cyclists. If expressed relative to body mass, the frontal drag of small cyclists is considerably greater than that of large cyclists. The difference in frontal drag (energy cost) is not made up for by the advantage to small cyclists in relative VO2max (energy supply), since the mass exponent for drag (1/3) is closer to zero than that for VO2max (2/3). Thus, small cyclists should be at a disadvantage in flat time trials, which field data support. The energy cost of riding uphill slightly favors the large cyclist, because the weight of the bicycle represents a relatively smaller load than it does to a small cyclist. The mass exponent is 0.79. Since this exponent is greater than that for VO2max, the small cyclists have an advantage in climbing, which is supported by field data. PMID:8133740

  1. 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.

  2. Public Bicycles: How the Concept of Human-Oriented “Mobility Sharing” Technology Can Influence Travel Behaviour Norms and Reshape Design Education

    OpenAIRE

    Nikitas, Alexandros; Wallgren, Pontus; Rahe, Ulrike

    2014-01-01

    Although at the moment an excess of 500 public bicycle schemes of variable sizes operate in almost 50 countries worldwide, the impact of their use on travel behaviour and modal change have neither been studied extensively nor have been understood thoroughly as yet. This work negotiates the initial stages of an international research scheme that means to look into the attitudes and system user experiences (the latter only when it is applicable) that could define the design (or re-design) crite...

  3. Does the effect of micro-environmental factors on a street's appeal for adults' bicycle transport vary across different macro-environments?: an experimental study

    OpenAIRE

    Lieze Mertens; Jelle Van Cauwenberg; Ariane Ghekiere; Veerle Van Holle; Ilse De Bourdeaudhuij; Benedicte Deforche; Jack Nasar; Nico Van de Weghe; Delfien Van Dyck

    2015-01-01

    Background : Characteristics of the physical environment can be classified into two broad categories: macro-("raw" urban planning features influenced on a regional level) and micro-(features specifically within a streetscape influenced on a neighborhood level) environmental factors. In urban planning applications, it is more feasible to modify conditions at the neighborhood level than at the regional level. Yet for the promotion of bicycle transport we need to know whether relationships betwe...

  4. Peptide Macrocycles Featuring a Backbone Secondary Amine: A Convenient Strategy for the Synthesis of Lipidated Cyclic and Bicyclic Peptides on Solid Support

    DEFF Research Database (Denmark)

    Oddo, Alberto; Münzker, Lena; Hansen, Paul Robert

    2015-01-01

    A convenient strategy for the on-resin synthesis of macrocyclic peptides (3- to 13-mers) via intramolecular halide substitution by a diamino acid is described. The method is compatible with standard Fmoc/tBu SPPS and affords a tail-to-side-chain macrocyclic peptide featuring an endocyclic seconda...... amine. This functional group is still reactive toward acylation, allowing for the continuation of the synthesis. An application to the synthesis of lipidated cyclic and bicyclic antimicrobial peptides is presented....

  5. An improved multi-value cellular automata model for heterogeneous bicycle traffic flow

    International Nuclear Information System (INIS)

    This letter develops an improved multi-value cellular automata model for heterogeneous bicycle traffic flow taking the higher maximum speed of electric bicycles into consideration. The update rules of both regular and electric bicycles are improved, with maximum speeds of two and three cells per second respectively. Numerical simulation results for deterministic and stochastic cases are obtained. The fundamental diagrams and multiple states effects under different model parameters are analyzed and discussed. Field observations were made to calibrate the slowdown probabilities. The results imply that the improved extended Burgers cellular automata (IEBCA) model is more consistent with the field observations than previous models and greatly enhances the realism of the bicycle traffic model. - Highlights: • We proposed an improved multi-value CA model with higher maximum speed. • Update rules are introduced for heterogeneous bicycle traffic with maximum speed 2 and 3 cells/s. • Simulation results of the proposed model are consistent with field bicycle data. • Slowdown probabilities of both regular and electric bicycles are calibrated

  6. Bicycle Guidelines and Crash Rates on Cycle Tracks in the United States

    Science.gov (United States)

    Morency, Patrick; Miranda-Moreno, Luis F.; Willett, Walter C.; Dennerlein, Jack T.

    2013-01-01

    Objectives. We studied state-adopted bicycle guidelines to determine whether cycle tracks (physically separated, bicycle-exclusive paths adjacent to sidewalks) were recommended, whether they were built, and their crash rate. Methods. We analyzed and compared US bicycle facility guidelines published between 1972 and 1999. We identified 19 cycle tracks in the United States and collected extensive data on cycle track design, usage, and crash history from local communities. We used bicycle counts and crash data to estimate crash rates. Results. A bicycle facility guideline written in 1972 endorsed cycle tracks but American Association of State Highway and Transportation Officials (AASHTO) guidelines (1974–1999) discouraged or did not include cycle tracks and did not cite research about crash rates on cycle tracks. For the 19 US cycle tracks we examined, the overall crash rate was 2.3 (95% confidence interval = 1.7, 3.0) per 1 million bicycle kilometers. Conclusions. AASHTO bicycle guidelines are not explicitly based on rigorous or up-to-date research. Our results show that the risk of bicycle–vehicle crashes is lower on US cycle tracks than published crashes rates on roadways. This study and previous investigations support building cycle tracks. PMID:23678920

  7. An improved multi-value cellular automata model for heterogeneous bicycle traffic flow

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Sheng [College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China (China); Qu, Xiaobo [Griffith School of Engineering, Griffith University, Gold Coast, 4222 Australia (Australia); Xu, Cheng [Department of Transportation Management Engineering, Zhejiang Police College, Hangzhou, 310053 China (China); College of Transportation, Jilin University, Changchun, 130022 China (China); Ma, Dongfang, E-mail: mdf2004@zju.edu.cn [Ocean College, Zhejiang University, Hangzhou, 310058 China (China); Wang, Dianhai [College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China (China)

    2015-10-16

    This letter develops an improved multi-value cellular automata model for heterogeneous bicycle traffic flow taking the higher maximum speed of electric bicycles into consideration. The update rules of both regular and electric bicycles are improved, with maximum speeds of two and three cells per second respectively. Numerical simulation results for deterministic and stochastic cases are obtained. The fundamental diagrams and multiple states effects under different model parameters are analyzed and discussed. Field observations were made to calibrate the slowdown probabilities. The results imply that the improved extended Burgers cellular automata (IEBCA) model is more consistent with the field observations than previous models and greatly enhances the realism of the bicycle traffic model. - Highlights: • We proposed an improved multi-value CA model with higher maximum speed. • Update rules are introduced for heterogeneous bicycle traffic with maximum speed 2 and 3 cells/s. • Simulation results of the proposed model are consistent with field bicycle data. • Slowdown probabilities of both regular and electric bicycles are calibrated.

  8. Predicting Free Flow Speed and Crash Risk of Bicycle Traffic Flow Using Artificial Neural Network Models

    Directory of Open Access Journals (Sweden)

    Cheng Xu

    2015-01-01

    Full Text Available Free flow speed is a fundamental measure of traffic performance and has been found to affect the severity of crash risk. However, the previous studies lack analysis and modelling of impact factors on bicycles’ free flow speed. The main focus of this study is to develop multilayer back propagation artificial neural network (BPANN models for the prediction of free flow speed and crash risk on the separated bicycle path. Four different models with considering different combinations of input variables (e.g., path width, traffic condition, bicycle type, and cyclists’ characteristics were developed. 459 field data samples were collected from eleven bicycle paths in Hangzhou, China, and 70% of total samples were used for training, 15% for validation, and 15% for testing. The results show that considering the input variables of bicycle types and characteristics of cyclists will effectively improve the accuracy of the prediction models. Meanwhile, the parameters of bicycle types have more significant effect on predicting free flow speed of bicycle compared to those of cyclists’ characteristics. The findings could contribute for evaluation, planning, and management of bicycle safety.

  9. Cyclist safety on bicycle boulevards and parallel arterial routes in Berkeley, California.

    Science.gov (United States)

    Minikel, Eric

    2012-03-01

    This study compares the safety of bicyclists riding on bicycle boulevards to those riding on parallel arterial routes in Berkeley, California. Literature on the impact of motor vehicle traffic characteristics on cyclist safety shows that high motor vehicle speeds and volumes and the presence of heavy vehicles are all detrimental to cyclist safety. This suggests that cyclists may be safer on side streets than on busy arterials. Bicycle boulevards-traffic-calmed side streets signed and improved for cyclist use-purport to offer cyclists a safer alternative to riding on arterials. Police-reported bicycle collision data and manually collected cyclist count data from bicycle boulevards and parallel arterial routes in Berkeley, California from 2003 to 2010 are used to test the hypothesis that Berkeley's bicycle boulevards have lower cyclist collision rates and a lower proportion of bicycle collisions resulting in severe injury. While no significant difference is found in the proportion of collisions that are severe, results show that collision rates on Berkeley's bicycle boulevards are two to eight times lower than those on parallel, adjacent arterial routes. The difference in collision rate is highly statistically significant, unlikely to be caused by any bias in the collision and count data, and cannot be easily explained away by self-selection or safety in numbers. Though the used dataset is limited and the study design is correlational, this study provides some evidence that Berkeley's bicycle boulevards are safer for cyclists than its parallel arterial routes. The results may be suggestive that, more generally, properly implemented bicycle boulevards can provide cyclists with a safer alternative to riding on arterials. PMID:22269506

  10. Energy Efficiency of Ultra-Low-Power Bicycle Wireless Sensor Networks Based on a Combination of Power Reduction Techniques

    Directory of Open Access Journals (Sweden)

    Sadik Kamel Gharghan

    2016-01-01

    Full Text Available In most wireless sensor network (WSN applications, the sensor nodes (SNs are battery powered and the amount of energy consumed by the nodes in the network determines the network lifespan. For future Internet of Things (IoT applications, reducing energy consumption of SNs has become mandatory. In this paper, an ultra-low-power nRF24L01 wireless protocol is considered for a bicycle WSN. The power consumption of the mobile node on the cycle track was modified by combining adjustable data rate, sleep/wake, and transmission power control (TPC based on two algorithms. The first algorithm was a TPC-based distance estimation, which adopted a novel hybrid particle swarm optimization-artificial neural network (PSO-ANN using the received signal strength indicator (RSSI, while the second algorithm was a novel TPC-based accelerometer using inclination angle of the bicycle on the cycle track. Based on the second algorithm, the power consumption of the mobile and master nodes can be improved compared with the first algorithm and constant transmitted power level. In addition, an analytical model is derived to correlate the power consumption and data rate of the mobile node. The results indicate that the power savings based on the two algorithms outperformed the conventional operation (i.e., without power reduction algorithm by 78%.

  11. Coordination chemistry of N-heterocyclic nitrenium-based ligands.

    Science.gov (United States)

    Tulchinsky, Yuri; Kozuch, Sebastian; Saha, Prasenjit; Mauda, Assaf; Nisnevich, Gennady; Botoshansky, Mark; Shimon, Linda J W; Gandelman, Mark

    2015-05-01

    Comprehensive studies on the coordination properties of tridentate nitrenium-based ligands are presented. N-heterocyclic nitrenium ions demonstrate general and versatile binding abilities to various transition metals, as exemplified by the synthesis and characterization of Rh(I) , Rh(III) , Mo(0) , Ru(0) , Ru(II) , Pd(II) , Pt(II) , Pt(IV) , and Ag(I) complexes based on these unusual ligands. Formation of nitrenium-metal bonds is unambiguously confirmed both in solution by selective (15) N-labeling experiments and in the solid state by X-ray crystallography. The generality of N-heterocyclic nitrenium as a ligand is also validated by a systematic DFT study of its affinity towards all second-row transition and post-transition metals (Y-Cd) in terms of the corresponding bond-dissociation energies.

  12. Synthesis of heterocycles through transition-metal-catalyzed isomerization reactions

    DEFF Research Database (Denmark)

    Ishøy, Mette; Nielsen, Thomas Eiland

    2014-01-01

    Metal-catalyzed isomerization of N- and O-allylic systems is emerging as an effective method to form synthetically useful iminium and oxocarbenium intermediates. In the presence of tethered nucleophiles, several recent examples illuminate this approach as a powerful strategy for the synthesis...... of structurally complex and diverse heterocycles. In this Concept article, we attempt to cover this area of research through a selection of recent versatile examples. A sea of opportunities! Transition-metal-catalyzed isomerization of N- and O-allylic compounds provides a mild, selective and synthetically...... versatile method to form iminium and oxocarbenium ions. Given the number of reactions involving these highly electrophilic intermediates, this concept provides a sea of opportunities for heterocycle synthesis, (see scheme; Nu=nucleophile). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim....

  13. Asymmetric Hydrogenation of Aromatic Heterocyclic Ketones Catalyzed by the MsDPEN–Cp*Ir(III) Complex

    OpenAIRE

    Utsumi, Noriyuki; Tsutsumi, Kunihiko; Watanabe, Masahiko; Murata, Kunihiko; Arai, Noriyoshi; Kurono, Nobuhito; Ohkuma, Takeshi

    2010-01-01

    Asymmetric hydrogenation of aromatic heterocyclic ketones catalyzed by Cp*Ir(OTf)(Msdpen) (MsDPEN = N-(methanesulfonyl)-1,2-diphenylethylenediamine) affords the heterocyclic alcohols in 93% to > 99% ee. The reaction is conducted in a methanolic solution with a substrate-to-catalyst molar ratio of 200-5000 under 15 atm of H2. The heterocyclic rings of substrates are left intact.

  14. Heterocyclization Approach for Electrooxidative Coupling of Functional Primary Alkylamines with Aromatics.

    Science.gov (United States)

    Morofuji, Tatsuya; Shimizu, Akihiro; Yoshida, Jun-ichi

    2015-08-12

    A new approach for electrooxidative coupling of aromatic compounds and primary alkylamines bearing a functional group such as a hydroxyl group and an amino group was developed. The key to the success of the transformation is heterocyclization of functional primary alkylamines. Treatment of primary alkylamines bearing a functional group with nitriles or their equivalents gives the corresponding heterocycles. The electrochemical oxidation of aromatic substrates in the presence of the heterocycles followed by chemical reaction under nonoxidative conditions gave the desired coupling products.

  15. DFT Studies of Mo-C Heterocyclic Rings

    Institute of Scientific and Technical Information of China (English)

    RAN Xiao-Rong; ZHAO Hai-Tao; ZHANG Wen-Qin

    2003-01-01

    @@ Eleven clusters of the six-membered Mo-C heterocyclic rings were calculated and compared with corresponding organic compounds. The structure, stability and the electronic properties of these clusters are discussed. All calcu- lations were carried out within the framework of the density functional theory (DFT) with a plane wave basis set, which encoded in VASP (Vienna Ab-initio Simulation Package). [1,2

  16. Exploring the Fate of Nitrogen Heterocycles in Complex Prebiotic Mixtures

    Science.gov (United States)

    Smith, Karen E.; Callahan, Michael P.; Cleaves, Henderson J.; Dworkin, Jason P.; House, Christopher H.

    2011-01-01

    A long standing question in the field of prebiotic chemistry is the origin of the genetic macromolecules DNA and RNA. DNA and RNA have very complex structures with repeating subunits of nucleotides, which are composed of nucleobases (nitrogen heterocycles) connected to sugar-phosphate. Due to the instability of some nucleobases (e.g. cytosine), difficulty of synthesis and instability of D-ribose, and the likely scarcity of polyphosphates necessary for the modern nucleotides, alternative nucleotides have been proposed for constructing the first genetic material. Thus, we have begun to investigate the chemistry of nitrogen heterocycles in plausible, complex prebiotic mixtures in an effort to identify robust reactions and potential alternative nucleotides. We have taken a complex prebiotic mixture produced by a spark discharge acting on a gas mixture of N2, CO2, CH4, and H2, and reacted it with four nitrogen heterocycles: uracil, 5-hydroxymethyluracil, guanine, and isoxanthopterin (2-amino-4,7-dihydroxypteridine). The products of the reaction between the spark mixture and each nitrogen heterocycle were characterized by liquid chromatography coupled to UV spectroscopy and Orbitrap mass spectrometry. We found that the reaction between the spark mixtUl'e and isoxanthopterin formed one major product, which was a cyanide adduct. 5-hydroxymethyluracil also reacted with the spark mixture to form a cyanide adduct, uracil-5-acetonitrile, which has been synthesized previously by reacting HCN with S-hydroxymethyluracil. Unlike isoxanthopterin, the chromatogram of the 5-hydroxymethyluracil reaction was much more complex with multiple products including spark-modified dimers. Additionally, we observed that HMU readily self-polymerizes in solution to a variety of oligomers consistent with those suggested by Cleaves. Guanine and uracil, the biological nucleobases, did not react with the spark mixture, even at high temperature (100 C). This suggests that there are alternative

  17. Synthesis of Different Heterocyclic Compounds of Pharmaceutical Relevance

    OpenAIRE

    Khan, Musharraf Naveed

    2013-01-01

    This thesis describes the synthesis of different cyclic imines and the exploration of their reactivity with cyclopropenones and 1,3-dipoles,as well as an investigation of the chemistry of the products. The synthesis of biologically and pharmaceutically important heterocyclic natural product analogues, such as the pyrroloazepines, indolizidines and pyrrolizidines has been achieved using a cycloaddition reaction between cyclic imidates and cyclopropenones. A new route to pyridines has been ...

  18. Optimal Time-Trial Bicycle Racing with Headwinds and Tailwinds

    CERN Document Server

    Anton, A Brad

    2013-01-01

    Many time-trial and triathlon bicycle races take place on relatively flat, closed-circuit courses. In the absence of hills, riding-speed is limited almost solely by aerodynamic drag; consequently, winds can have a big effect on elapsed times. I analyze the special case of a straight out-and-back race in a steady wind, assuming the rider has a given total amount of energy to expend and can choose only two speeds - the aided speed with tailwind and the hindered speed into headwind. In this ideal circumstance the problem of choosing optimal riding speeds reduces to a constrained nonlinear optimization that can be solved with elementary calculus. My analysis reveals a practical rule of thumb that can be used more generally to choose optimal riding speeds for time-trial racing on closed-circuit courses in the presence of headwinds and tailwinds.

  19. [Prognostic significance of bicycle ergometry test in patients with myocarditis].

    Science.gov (United States)

    Gavalova, R F; Borodina, V I

    1992-04-01

    A total of 42 patients with rheumatic carditis were examined in the acute-subacute period and following 3-5 years. Seventeen patients were diagnosed as having primary rheumatic carditis, 9 presented with tonsillogenic rheumatic carditis, and 16 had viral rheumatic carditis. The diagnosis of myocarditis was established on the basis of clinical, immunological, and virological findings. The study involved ECG, PhCG, PCG, and bicycle ergometer testing recordings. Groups of patients with good and poor prognosis were identified. Low threshold exercise, exercise-inadequate tachycardia, complex cardiac arrhythmias, phasic myocardial hypodynamic syndrome and volume exercise syndrome that are formed during performance are prognostically poor indicators. More profound electric and mechanic dysfunctions were observed in patients with tonsillogenic or viral myocarditis.

  20. Synthesis of bicyclic alkaloids from the iridoid antirrhinoside

    DEFF Research Database (Denmark)

    Frederiksen, Signe Maria

    The present thesis describes the isolation of the iridoid glucoside antirrhinoside from Antirrhinum majus, and the approaches made towards its transformation into analogues of biologically active compounds, with special interest in syntheses of bicyclic alkaloids.A synthetic piperidine monoterpene...... alkaloid was prepared from antirrhinoside by means of an enzymatic cleavage to afford the aglucone, followed by a double reductive amination with benzylamine hydrochloride and sodium cyanoborohydride. The resulting piperidine was modified by opening of the epoxide on the cyclopropane ring by azide...... strategy was therefore abandoned.A one-pot reaction involving ozonolysis and subsequent reduction of the 5,6-O-isopropylidene-2',3',4',6'-tetra-O-acetyl antirrhinoside yielded a diol, which was considered a potential intermediate in the preparation of enantiopure 3-azabicyclo[3.3.0]octane alkaloids...

  1. Consumers’ preferences for “bicycle poultry” in Benin

    DEFF Research Database (Denmark)

    Sodjinou, Epiphane; Henningsen, Arne; Koudande, Delphin O.;

    Village poultry, also termed "bicycle poultry," is produced in scavenging farming systems and is a chewy meat with a low fat content, and constitutes an important source of meat in many African countries. This study investigates consumers’ preferences regarding the physical traits of these birds...... are willing to pay a premium for these types of birds. The factors which significantly influence the price of chicken are the breed of the bird, the plumage color, the meatiness and the age of the bird. Consumers are willing to pay a price premium for meatier birds of traditional breeds with white plumage...... color and aged between six and twelve months. Thus, efforts to improve local breeds should stress these preferred traits....

  2. Aromatic Esters of Bicyclic Amines as Antimicrobials against Streptococcus pneumoniae.

    Science.gov (United States)

    de Gracia Retamosa, María; Díez-Martínez, Roberto; Maestro, Beatriz; García-Fernández, Esther; de Waal, Bas; Meijer, E W; García, Pedro; Sanz, Jesús M

    2015-11-01

    A double approach was followed in the search of novel inhibitors of the surface choline-binding proteins (CBPs) of Streptococcus pneumoniae (pneumococcus) with antimicrobial properties. First, a library of 49 rationally-designed esters of alkyl amines was screened for their specific binding to CBPs. The best binders, being esters of bicyclic amines (EBAs), were then tested for their in vitro effect on pneumococcal growth and morphology. Second, the efficiency of EBA-induced CBP inhibition was enhanced about 45,000-fold by multivalency effects upon synthesizing a poly(propylene imine) dendrimer containing eight copies of an atropine derivative. Both approaches led to compounds that arrest bacterial growth, dramatically decrease cell viability, and exhibit a protection effect in animal disease models, demonstrating that the pneumococcal CBPs are adequate targets for the discovery of novel antimicrobials that overcome the currently increasing antimicrobial resistance issues. PMID:26377931

  3. Compositions comprising a polypeptide having cellulolytic enhancing activity and a heterocyclic compound and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Feng; Sweeney, Matthew; Quinlan, Jason

    2016-08-02

    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a heterocyclic compound. The present invention also relates to methods of using the compositions.

  4. Nucleobases in Space: Laboratory Studies of Polycyclic Aromatic Nitrogen Heterocycles

    Science.gov (United States)

    Elsila, Jamie; Mattioda, Andy; Bernstein, Max; Sandford, Scott; Hudgins, Doug

    2005-01-01

    Polycyclic Aromatic Nitrogen Heterocycles (PANHs) are heterocyclic aromatics Le., PAHs with carbon atoms replaced by a nitrogen atom. These molecules have been detected in meteorite extracts, and in general these nitrogen heterocycles are of astrobiological interest since this class of molecules include nucleobases, basic components of our nucleic acids. These compounds are predicted to be present in the interstellar medium and in Titan tholin, but have received relatively little attention. We will present spectra and reactions of PANHs, frozen in solid H2O at 12 K, conditions germane to astronomical observations. In contrast to simple PAHs, that do not interact strongly with solid H2O, the nitrogen atoms in PANHs are potentially capable of hydrogen bonding with H20 changing their spectra, complicating their remote detection on the surfaces of icy bodies. Moreover, we have studied the photo-chemistry of these interesting compounds under astrophysical conditions and will use our lab studies to assess a potential interstellar heritage of these compounds in carbonaceous chondrites.

  5. Dancing with Energetic Nitrogen Atoms: Versatile N-Functionalization Strategies for N-Heterocyclic Frameworks in High Energy Density Materials.

    Science.gov (United States)

    Yin, Ping; Zhang, Qinghua; Shreeve, Jean'ne M

    2016-01-19

    has become an increasingly efficient tool for exploring new HEDMs with both high energy and low sensitivity. As a highly dense building block, introduction of oxygen not only improves density significantly but also gives rise to a better oxygen balance. Furthermore, the N-O functionalized strategy is highly suitable for a broad variety of N-heterocycles including five-membered azoles and six-membered azines. Newly explored N-halogen and N-B functionalization strategies have endowed the resulting HEDMs with some new energetic characteristics. Typical examples include the N-halogenated fused triazole and FOX-7 as potential hypergolic oxidizers with very short ignition delay times. In addition, some exploratory studies of N-B functionalized heterocycles have expanded energetic applications as hypergolic ionic liquids, green pyrotechnic colorants, and high-oxygen carriers. Overall, flexible N-functionalization methodologies involving different N-X bond formation have not only provided an efficient approach to diverse energetic ingredients but also expanded the application scope of energetic materials. Discussion and perspectives of N-functionalized protocols are given to summarize possible structure-property correlations, thus providing efficient guidelines for future design of new HEDMs. PMID:26717271

  6. Synthesis and screening of bicyclic carbohydrate-based compounds: a novel type of antivirals.

    Science.gov (United States)

    Van Hoof, Steven; Ruttens, Bart; Hubrecht, Idzi; Smans, Gert; Blom, Petra; Sas, Benedikt; Van hemel, Johan; Vandenkerckhove, Jan; Van der Eycken, Johan

    2006-03-15

    A small library of bicyclic carbohydrate derivatives was synthesized and screened. A strong and selective activity against cytomegalovirus was found. Structure-activity relationship for this new type of antivirals is discussed.

  7. Prioritization of Integrated Bicycle Network Clusters in Istanbul Using Analytic Hierarchy Process

    Directory of Open Access Journals (Sweden)

    Dilek Çol Yılmaz

    2014-06-01

    Full Text Available In this study, the impact of the integration of nonmotorized transport and public transport on hypermobility was evaluated. The role of bicycle in non-motorized transportation, and its contribution to sustainable travel goals were examined. A decision support model was established in order to plan the phases of a bicycle network integrated with the public transport sytem in Istanbul Metropolitan Area. Data such as public transport routes planned for the target year 2023, locations of transfer centers, number of passengers at transfer centers, and a revised bicycle network were used as layers for the Geographic Information Systems (GIS map produced. Based on the survey data collected from the experts, Analytic Hierarchy Process (AHP which is a multi-criteria decision-making procedure that contains both qualitative and quantitative factors was used to prioritize the bicycle network clusters integrated with public transport system in Istanbul.

  8. EU to Continue 48.5% Anti-dumping Duties on Chinese Bicycles

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    On June 10, European Commission informed the Business Office of the Mission of Ministry of Commerce in EU and disclosed the adjudication on the review of the EU imposing anti-dumping on Chinese bicycles.

  9. Sleep Deprivation Is Associated with Bicycle Accidents and Slip and Fall Injuries in Korean Adolescents.

    Directory of Open Access Journals (Sweden)

    So Young Kim

    Full Text Available This study sought to evaluate associations between sleep time and bicycle accidents, falls under various circumstances, and dental injuries in adolescents.A total of 61,696 participants ranging from 12 to 18 years of age who completed the Korea Youth Risk Behavior Web-based Survey (KYRBWS in 2013 were enrolled in this study. Bicycle riding accidents were analyzed for 17,232 bicycle-riding participants. Data were collected regarding the weekday sleep duration for the most recent 7 days, which was categorized as the 5.5-6.5 h group > the 6.5-7.5 h group. There was no significant relationship between sleep deprivation and dental injury.This study demonstrated that sleep deprivation among Korean adolescents was associated with bicycle accidents and falls at home and school. Thus, adequate sleep may be needed to prevent accidents and falls.

  10. Physiological responses and exercise preference between the Trikke and the bicycle ergometer

    Directory of Open Access Journals (Sweden)

    Eddie T.C. Lam

    2016-06-01

    Conclusion: Participants were more efficient in using the Trikke than the bicycle ergometer. The Trikke may be an enjoyable alternative for those individuals, particularly women, who have lost interest in traditional forms of exercise.

  11. An Analyses of Bicycle Accidents in Ankara: Analyses of 5 Years

    Directory of Open Access Journals (Sweden)

    Muhittin Yilmaz

    2014-12-01

    Full Text Available Aim: Bicycles are used for transportation, exercise and recreation. In this study we aimed to investigate the epidemiological, clinical and economic aspects of bicycle injuries. Material and Method: We included in the study who admitted to the Emergency Department with a bicycle accident between January 2008 and July 2012. Patient age and sex, accident pattern, presence of personal protective measures, injured body part, Glasgow Coma Scale (GCS score, Revised Trauma Score (RTS, radiological findings, requested consultations, duration of hospital stay, season of injury, and average cost rates were recorded. The study population was divided into 2 age groups as 0-14 years and over 14 years. Results: A patients were 238 (81.2% male and their mean age was 31.5±14.1 years. Fifty-five (18.8% patients were female and their mean age was 34.5±15.9 years. Males had significantly higher rate of bicycle injury (p

  12. Exploitation of in situ generated sugar-based olefin keto-nitrones: synthesis of carbocycles, heterocycles, and nucleoside derivatives.

    Science.gov (United States)

    Das, Soumendra Nath; Chowdhury, Arpan; Tripathi, Neha; Jana, Prithwish K; Mandal, Sukhendu B

    2015-01-16

    Application of intramolecular 1,3-dipolar nitrone cycloaddition reaction on carbohydrate-derived precursors containing an olefin functionality at C-1 or C-3 or C-5 and a nitrone moiety at C-2 or C-3 as appropriate has resulted in the formation of structurally new cycloaddition products containing furanose-fused oxepane, thiepane, azepane, cyclopentane, cycloheptane, tetrahydrofuran, and pyranose-fused tetrahydrofuran rings. The structure and stereochemistry of these products have been characterized by spectral as well as single-crystal X-ray analyses. Two of the compounds have been transformed to the bicyclic nucleoside derivatives applying Vorbrüggen reaction conditions.

  13. Isn't it time to take bicycles seriously again in Beijing ?%Isn't it time to take bicycles seriously again in Beijing ?

    Institute of Scientific and Technical Information of China (English)

    Shannon Bufton; Florian Lorenz

    2011-01-01

    The humble bicycle was once the predominant mode of transport in Beijing and it can be argued that the city has previously been one of the best bicycle cities in the world. Now the streets are littered with rusting old bikes and it seems as if Beijing has turned its back on the bicycle in its quest for modernity and evolution. The resultant re-configuration of the city and the rapid speed of development of modern transportation systems (particularly the lightening growth of personal automobiles) have created a complex set of issues and challenges which now put the city under pressure such as sustainability, air quality, health and traffic congestion problems.

  14. Synthesis and Reactions of Five-Membered Heterocycles Using Phase Transfer Catalyst (PTC Techniques

    Directory of Open Access Journals (Sweden)

    Ahmed M. El-Sayed

    2014-01-01

    Full Text Available Phase transfer catalysts (PTCs have been widely used for the synthesis of organic compounds particularly in both liquid-liquid and solid-liquid heterogeneous reaction mixtures. They are known to accelerate reaction rates by facilitating formation of interphase transfer of species and making reactions between reagents in two immiscible phases possible. Application of PTC instead of traditional technologies for industrial processes of organic synthesis provides substantial benefits for the environment. On the basis of numerous reports it is evident that phase-transfer catalysis is the most efficient way for generation and reactions of many active intermediates. In this review we report various uses of PTC in syntheses and reactions of five-membered heterocycles compounds and their multifused rings.

  15. Modeling and simulation of the transmission system for a chainless electric bicycle

    OpenAIRE

    Garcia Farreny, Alex

    2015-01-01

    This project, entitled Modeling and Simulation of the Transmission System for a Chainless Electric Bicycle, consists in the design of the controllers’ logics governing a chainless electric bicycle’s transmission in order to accomplish certain behavior in front of inputs such as pedaling torque, slope gradient, frontal wind, gear selected, etc. To better understand it, a chainless electric bicycle replaces the conventional mechanical transmission (chain) by two electric mac...

  16. Teaching children about bicycle safety: an evaluation of the New Jersey Bike School program.

    Science.gov (United States)

    Lachapelle, Ugo; Noland, Robert B; Von Hagen, Leigh Ann

    2013-03-01

    There are multiple health and environmental benefits associated with increasing bicycling among children. However, the use of bicycles is also associated with severe injuries and fatalities. In order to reduce bicycle crashes, a bicycling education program was implemented in selected New Jersey schools and summer camps as part of the New Jersey Safe Routes to School Program. Using a convenience sample of participants to the program, an opportunistic study was designed to evaluate the effectiveness of two bicycle education programs, the first a more-structured program delivered in a school setting, with no on-road component, and the other a less structured program delivered in a summer camp setting that included an on-road component. Tests administered before and after training were designed to assess knowledge acquired during the training. Questions assessed children's existing knowledge of helmet use and other equipment, bicycle safety, as well as their ability to discriminate hazards and understand rules of the road. Participating children (n=699) also completed a travel survey that assessed their bicycling behavior and their perception of safety issues. Response to individual questions, overall pre- and post-training test scores, and changes in test scores were compared using comparison of proportion, t-tests, and ordinary least-squares (OLS) regression. Improvements between the pre-training and post-training test are apparent from the frequency distribution of test results and from t-tests. Both summer camps and school-based programs recorded similar improvements in test results. Children who bicycled with their parents scored higher on the pre-training test but did not improve as much on the post-training test. Without evaluating long-term changes in behavior, it is difficult to ascertain how successful the program is on eventual behavioral and safety outcomes.

  17. A novel stereoselective synthesis of N-heterocycles by intramolecular hydrovinylation

    DEFF Research Database (Denmark)

    Bothe, Ulrich; Rudbeck, H. C.; Tanner, David Ackland;

    2001-01-01

    A novel method for the synthesis of bicyclic amines has been developed. Cyclisation of 1,6-dienes by intramolecular hydrovinylation in the presence of catalytic amounts of allylpalladium chloride dimer afforded bicyclic amines in one step. Added phosphines, silver salts, as well as the nature of ...

  18. A Modified Cellular Automaton Approach for Mixed Bicycle Traffic Flow Modeling

    Directory of Open Access Journals (Sweden)

    Xiaonian Shan

    2015-01-01

    Full Text Available Several previous studies have used the Cellular Automaton (CA for the modeling of bicycle traffic flow. However, previous CA models have several limitations, resulting in differences between the simulated and the observed traffic flow features. The primary objective of this study is to propose a modified CA model for simulating the characteristics of mixed bicycle traffic flow. Field data were collected on physically separated bicycle path in Shanghai, China, and were used to calibrate the CA model using the genetic algorithm. Traffic flow features between simulations of several CA models and field observations were compared. The results showed that our modified CA model produced more accurate simulation for the fundamental diagram and the passing events in mixed bicycle traffic flow. Based on our model, the bicycle traffic flow features, including the fundamental diagram, the number of passing events, and the number of lane changes, were analyzed. We also analyzed the traffic flow features with different traffic densities, traffic components on different travel lanes. Results of the study can provide important information for understanding and simulating the operations of mixed bicycle traffic flow.

  19. Bicycle helmet use and non-use – recently published research

    Science.gov (United States)

    2012-01-01

    Bicycle traumata are very common and especially neurologic complications lead to disability and death in all stages of the life. This review assembles the most recent findings concerning research in the field of bicycle traumata combined with the factor of bicycle helmet use. The area of bicycle trauma research is by nature multidisciplinary and relevant not only for physicians but also for experts with educational, engineering, judicial, rehabilitative or public health functions. Due to this plurality of global publications and special subjects, short time reviews help to detect recent research directions and provide also information from neighbour disciplines for researchers. It can be stated that to date, that although a huge amount of research has been conducted in this area more studies are needed to evaluate and improve special conditions and needs in different regions, ages, nationalities and to create successful prevention programs of severe head and face injuries while cycling. Focus was explicit the bicycle helmet use, wherefore sledding, ski and snowboard studies were excluded and only one study concerning electric bicycles remained due to similar motion structures within this review. The considered studies were all published between January 2010 and August 2011 and were identified via the online databases Medline PubMed and ISI Web of Science. PMID:22632628

  20. Association of Sociodemographic and Perceived Environmental Factors with Public Bicycle Use among Taiwanese Urban Adults

    Directory of Open Access Journals (Sweden)

    Yung Liao

    2016-03-01

    Full Text Available Background: This study examined the sociodemographic and perceived environmental factors associated with public bicycle use among Taiwanese urban adults. Methods: A random-digit-dialing telephone-based cross-sectional survey was administered to Taiwanese urban adults aged 20–64 years in 2015. Data on sociodemographic variables, perceived environmental factors (for attributes identified in the International Physical Activity Questionnaire-Environmental Module, and public bicycle use were obtained from 1002 adults in three cities. Adjusted logistic regression was used. Results: After adjustment for potential confounders, the results showed that adults aged 20–29 years (odds ratio (OR = 4.42 with a university degree or higher (OR = 2.03 were more likely to use public bicycles. In addition, adults living in Kaohsiung City were less likely to use public bicycles (OR = 0.24. Adults who saw people being active (OR = 1.76; 95% CI: 1.05–2.86 and had positive aesthetic experiences of their environment (OR = 1.69 were more likely to use public bicycles. Conclusions: Our findings suggest that seeing physically active people and positive aesthetic perceptions of the environment are key factors for developing transportation policies and intervention strategies for promoting public bicycle use among Taiwanese urban adults.

  1. Implications of dynamic imine chemistry for the sustainable synthesis of nitrogen heterocycles via transimination followed by intramolecular cyclisation.

    Science.gov (United States)

    Laha, Joydev K; Tummalapalli, K S Satyanarayana; Jethava, Krupal P

    2016-02-28

    An exploration of a tandem approach to the sustainable synthesis of N-heterocycles from readily available N-aryl benzylamines or imines and ortho-substituted anilines is described, which demonstrates, for the first time, an important synthetic application of dynamic imine chemistry. The key features to the successful development of this protocol include the utilisation of N-aryl benzylamines as imine precursors in transimination, the occurrence of transimination in acetonitrile in the absence of any catalysts, an intramolecular nucleophilic addition occurring in the newly formed imine causing irreversible transimination, and the tandem event occurring under green conditions.

  2. Synthesis of quinoline based heterocyclic compounds for blue lighting application

    Science.gov (United States)

    Kumar, Vinod; Gohain, Mukut; Van Tonder, Johannes H.; Ponra, S.; Bezuindenhoudt, B. C. B.; Ntwaeaborwa, O. M.; Swart, H. C.

    2015-12-01

    2,4-Diphenylquinoline (DPQ), derivatives 6-chloro-2,4-diphenylquinoline (DPQ-Cl) and 4‧,6-dichloro-2,4-diphenylquinoline (DPQ-Cl2) were synthesized using a three-component domino reaction. The DPQ, DPQ-Cl and DPQ-Cl2 were characterized by nuclear magnetic resonance spectroscopy, scanning electron microscopy, thermogravimetric analysis (TGA). Fourier transformed infra-red spectroscopy, X-ray photoelectron spectroscopy (XPS), Ultraviolet-visible (UV-vis) spectroscopy and photoluminescence spectroscopy. The TGA results showed that the DPQ was more thermally stable with respect to the DPQ-Cl and DPQ-Cl2. The synthesized organic phosphors showed bright emission in the blue region under an UV excitation wavelength of 325 nm with the power of 18 mW. These organic phosphors were found to be efficient candidate and may be used in organic blue light emitting devices.

  3. Microwave-assisted synthesis of bio-active heterocycles in aqueous media

    KAUST Repository

    Polshettiwar, Vivek

    2010-01-01

    Synthesis of bio-active heterocycles and fine chemicals in aqueous media are one of the best solutions for the development of green and sustainable protocols. To illustrate the advantages of aqueous MW chemistry in heterocycle synthesis, in this chapter, various synthetic pathways developed in recent years in aqueous reaction media using microwave irradiation are described.

  4. N-heterocyclic carbene catalyzed synthesis of dimethyl carbonate via transesterification of ethylene carbonate with methanol

    OpenAIRE

    Guang-Fen Du; Hao Guo; Ying Wang; Wen-Juan Li; Wei-Jie Shi; Bin Dai

    2015-01-01

    An organocatalytic protocol for the synthesis of dimethyl carbonate has been developed. Under the catalysis of 5 mol% N-heterocyclic carbenes, ethylene carbonate undergoes transesterification reaction with methanol under very mild reaction conditions, producing dimethyl carbonate with high efficiency. Furthermore, this N-heterocyclic carbene promoted transesterification can be scaled-up easily without lose of the conversion of dimethyl carbonate.

  5. The Depolymerization of Poly(Ethylene Terephthalate) (PET) Using N-Heterocyclic Carbenes from Ionic Liquids

    Science.gov (United States)

    Kamber, Nahrain E.; Tsujii, Yasuhito; Keets, Kate; Waymouth, Robert M.; Pratt, Russell C.; Nyce, Gregory W.; Hedrick, James L.

    2010-01-01

    The depolymerization of the plastic polyethylene terephthalate (PET or PETE) is described in this laboratory procedure. The transesterification reaction used to depolymerize PET employs a highly efficient N-heterocyclic carbene catalyst derived from a commercially available imidazolium ionic liquid. N-heterocyclic carbenes are potent nucleophilic…

  6. Carbon-14 labelled nitrogen heterocycles; the syntheses of three phosphodiesterase inhibitors

    International Nuclear Information System (INIS)

    The syntheses of three heterocyclic phosphodiesterase inhibitors are described from a common radiolabelled precursor, namely 2-propoxybenzo[cyano-14C] nitrile. Conversion of the nitrile to the corresponding methyl ketone or amidine allows elaboration of the heterocycles radiolabelled within the ring systems. (Author)

  7. The Effects of Surface-Induced Loads on Forearm Muscle Activity During Steering a Bicycle

    Science.gov (United States)

    Arpinar-Avsar, Pinar; Birlik, Gülin; Sezgin, Önder C.; Soylu, Abdullah R.

    2013-01-01

    On the bicycle, the human upper extremity has two essential functions in steering the bicycle and in supporting the body. Through the handlebar, surface- induced loads are transmitted to the hand and arm of the bicycle rider under vibration exposure conditions. Thus, the purpose of the study was to investigate the effect of vibration exposure on forearm muscle activity for different road surfaces (i.e. smooth road, concrete stone pavement, rough road) and for different bicycles. Ten subjects participated in experiments and two types of bicycles, i.e. Road Bike (RB) and Mountain Bike (MTB) are compared. The acceleration magnitudes were dominant along x and z-axes. The r.m.s acceleration values in the z direction at the stem of MTB were at most 2.56, 7.04 and 10.76 m·s-2 when pedaling respectively on asphalt road, concrete pavement and rough road. In the case of RB the corresponding values were respectively 4.43, 11.75 and 27.31 m·s-2. The cumulative normalized muscular activity levels during MTB trials on different surfaces had the same tendency as with acceleration amplitudes and have ranked in the same order from lowest to highest value. Although road bike measurements have resulted in a similar trend of increment, the values computed for rough road trials were higher than those in MTB trials. During rough road measurements on MTB, rmsEMG of extensor muscles reached a value corresponding to approximately 50% of MVC (Maximum Voluntary Contraction). During RB trials performed on rough road conditions, rmsEMG (%MVC) values for the forearm flexor muscles reached 45.8% of their maximal. The level of muscular activity of forearm muscles in controlling handlebar movements has been observed to be enhanced by the increase in the level of vibration exposed on the bicycle. Since repeated forceful gripping and pushing forces to a handle of a vibratory tool can create a risk of developing circulatory, neurological, or musculoskeletal disorder, a bicycle rider can be

  8. Incidence and costs of bicycle-related traumatic brain injuries in the Netherlands.

    Science.gov (United States)

    Scholten, Annemieke C; Polinder, Suzanne; Panneman, Martien J M; van Beeck, Ed F; Haagsma, Juanita A

    2015-08-01

    The main cause of death and serious disability in bicycle accidents is traumatic brain injury (TBI). The aim of this population-based study was to assess the incidence and costs of bicycle-related TBI across various age groups, and in comparison to all bicycle-related injuries, to identify main risk groups for the development of preventive strategies. Data from the National Injury Surveillance System and National Medical Registration were used for all patients with bicycle-related injuries and TBI who visited a Dutch emergency department (ED) between 1998 and 2012. Demographics and national, weighted estimates of injury mechanism, injury severity and costs were analysed per age group. Direct healthcare costs and indirect costs were determined using the incidence-based Dutch Burden of Injury Model. Between 1998 and 2012, the incidence of ED treatments due to bicycle-related TBI strongly increased with 54%, to 43 per 100,000 persons in 2012. However, the incidence of all bicycle-related injuries remained stable, from 444 in 1998 to 456/100,000 in 2012. Incidence of hospital admission increased in both TBI (92%) and all injuries from cycling (71%). Highest increase in incidence of both ED treatments and hospital admissions was seen in adults aged 55+. The injury rate of TBI per kilometre travelled increased (44%) except in children, but decreased (-4%) for all injuries, showing a strong decrease in children (-36%) but an increase in men aged 25+, and women aged 15+. Total costs of bicycle-related TBI were €74.5 million annually. Although bicycle-related TBI accounted for 9% of the incidence of all ED treatments due to cycling, it accounted for 18% of the total costs due to all bicycle-related injuries (€410.7 million). Children and adolescents (aged 0-24) had highest incidence of ED treatments due to bicycle-related injuries. Men in the working population (aged 15-64) had highest indirect costs following injuries from cycling, including TBI. Older cyclists (aged

  9. Synthesis and properties of Oxasmaragdyrins containing one Five-membered Heterocycle at Meso-position

    Indian Academy of Sciences (India)

    BOORUGA UMASEKHAR; PALLAB SAMANTA; TAMAL CHATTERJEE; MANGALAMPALLI RAVIKANTH

    2016-11-01

    The oxasmaragdyrins containing one five membered heterocycle such as pyrrole, thiophene and furan in place of one of the meso-phenyl group were synthesized by acid-catalyzed oxidative coupling reaction of meso-heterocycle substituted dipyrromethane with 16-oxatripyrrane in the presence of catalytic amountof trifluoroacetic acid followed by oxidation with DDQ. The smaragdyrin macrocycles containing one fivemembered heterocycle at meso-position were characterized by HR-MS and detailed 1D and 2D NMR studies. The absorption and fluorescence studies revealed that the presence of five membered heterocycle at mesoposition of smaragdyrin resulted in bathochromic shifts in absorption and emission bands with slight reduction in quantum yields compared to smraragdyrin macrocycle containing six membered meso-phenyl groups. Theelectrochemical studies revealed that the meso-heterocycle smaragdyrins are electron deficient compared to meso-phenyl smaragdyrins.

  10. Trends in research of antitrypanosomal agents among synthetic heterocycles.

    Science.gov (United States)

    Kryshchyshyn, Anna; Kaminskyy, Danylo; Grellier, Philippe; Lesyk, Roman

    2014-10-01

    To date treatment of trypanosomiasis urgently requires new effective and non-toxic drugs. The article covers some of the achievements in the search for new antitrypanosomal agents; also the "validated" biological targets used in the antitrypanosomal agents design are outlined. The major part of the manuscript focuses on the synthetic small molecules, such as thiosemicarbazone and thiazole (as their cyclic analogues) derivatives, benzofuran derivatives, heterocycles bearing nitro group etc. Also, the attractiveness of metal complexes and well known drugs as sources for antitrypanosomal agent design is discussed. PMID:25072876

  11. O,S-Heterocyclic stannylenes: synthesis and reactivity.

    Science.gov (United States)

    Karwasara, Surendar; Jha, Chandan Kumar; Sinhababu, Soumen; Nagendran, Selvarajan

    2016-04-25

    Commercially available N-oxide (2-mercaptopyridine-N-oxide) is used as a ligand instead of an oxidizing agent to stabilize the compounds of main group elements in low-valent states. The isolated compounds [(C5H4NOS)2Sn (), (C5H4NOS)SnCl () and (C5H4NOS)GeCl ()] are the first structurally characterized examples of O,S-heterocyclic stannylenes and germylenes with interesting bonding features. Further, the reaction of compound with SbCl3 afforded the rare dichlorodiantimony oxide [{(C5H4NOS)SbCl}2O] () unprecedentedly. PMID:27049924

  12. Synthesis of Heterocyclic Ring Systems Using Organometallic Reagents

    Institute of Scientific and Technical Information of China (English)

    Sameer Agarwal; Jan Kn(o)ll; Micha P. Krahl; Hans-Joachim Kn(o)lker

    2005-01-01

    @@ 1Introduction We developed novel synthetic routes to heterocyclic ring systems by using transition metal-mediated or -catalyzed reactions. A Lewis acid-promoted addition of the propargyl Grignard reagent 2 to the Schiff base 1 followed by a silvermediated oxidative cyclization of the homopropargylamine 3 provided the aryl-substituted pyrrole 4. Combined with a chemoselective hydrogenation of the pyrrole ring, this method has been applied to the total synthesis of the biologically active fused indolizidine alkaloids ( ± )-harmicine and ( ± )-crispine A[1]. See Fig. 1.

  13. Nanofiber composites containing N-heterocyclic carbene complexes with antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Elzatahry AA

    2012-06-01

    Full Text Available Ahmed A Elzatahry1,4, Abdullah M Al-Enizi1, Elsayed Ahmed Elsayed2,5, Rachel R Butorac3, Salem S Al-Deyab1, Mohammad AM Wadaan2, Alan H Cowley31Petrochemical Research Chair, Department of Chemistry, 2Chair of Advanced Proteomics & Cytomics Research, Faculty of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia; 3Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX, USA; 4Institute of Advanced Technology and New Materials, City for Scientific Research and Technology Applications, New Borg Alrab, Alexandria, Egypt; 5Natural & Microbial Products Department, National Research Centre, Dokki, Cairo, EgyptAbstract: This report concerns nanofiber composites that incorporate N-heterocyclic carbenes and the use of such composites for testing antimicrobial and antifungal activities. The nanofiber composites were produced by electrospinning mixtures of the gold chloride or gold acetate complexes of a bis(iminoacenaphthene (BIAN-supported NHC with aqueous solutions of polyvinyl alcohol (PVA. The products were characterized by scanning-electron microscopy, which revealed that nanofibers in the range of 250–300 nm had been produced. The biological activities of the nanofiber composites were tested against two Gram-positive bacteria, six Gram-negative bacteria, and two fungal strains. No activity was evident against the fungal strains. However, the gold chloride complex was found to be active against all the Gram-positive pathogens and one of the Gram-negative pathogens. It was also found that the activity of the produced nanofibers was localized and that no release of the bioactive compound from the nanofibers was evident. The demonstrated antimicrobial activities of these novel nanofiber composites render them potentially useful as wound dressings.Keywords: nanofiber, electrospinning, N-Heterocyclic carbene, biopolymer, antimicrobial

  14. Optimization of electric bicycle for youths with disabilities.

    Science.gov (United States)

    Blumenstein, Tobias; Zeitlmann, Hilar; Alves-Pinto, Ana; Turova, Varvara; Lampe, Renée

    2014-01-01

    Cerebral palsy is a group of neurodevelopmental disorders that affect a person's ability to move and to maintain balance and posture. People with cerebral palsy have also perception and space orientation deficits so that special assistance devices should be developed to compensate these handicaps. The objective was to optimize an adapted electric bicycle (E-bike) for youths with neurodevelopmental disorders. An adapted E-bike was provided with ultrasonic sensors that measure distances to objects. If the distance to other objects reduces, an acoustic signal is sent. Additionally, a self-created force plate was fixed on the pedal to evaluate the muscle performances during biking. An experiment with the ultrasound warning system confirmed that acoustic feedback was helpful in avoiding obstacles. The measurement of the blood pressure, the heart frequency and the pedaling force during biking approved that the training condition of the test person can be registered and enables tuning the power of the electric motor to individual requirements. The results demonstrate that an adapted E-bike can be improved to provide better space orientation for people with perceptual disorders and to measure training conditions of patients. Moreover, these enable individual adjustment of the electric motor power to optimize comfort and therapy effect. PMID:25485189

  15. Environmental Determinants of Bicycling Injuries in Alberta, Canada

    Directory of Open Access Journals (Sweden)

    Nicole T. R. Romanow

    2012-01-01

    Full Text Available This study examined environmental risk factors for bicycling injuries, by combining data on bicyclist injuries collected by interviews in the emergency department (ED with street-level environmental audits of injury locations, capturing path, roadway, safety, land use, and aesthetic characteristics. Cases were bicyclists struck by a motor vehicle (MV or with severe injuries (hospitalized. Controls were bicyclists who were not hit by a car or those seen and discharged from the ED, matched on time and day of injury. Logistic regression odds ratios (ORs adjusted for age, sex, peak time, and bicyclist speed with 95% confidence intervals (CIs were estimated to relate injury risk to environmental characteristics. Factors contributing to MV events included greater traffic volume (OR 5.13; 95% CI [1.44, 18.27], intersections (OR 6.89; 95% CI [1.48, 32.14], retail establishments (OR 5.56; 95% CI [1.72, 17.98], and path obstructions (OR 3.83; 95% CI [1.03, 14.25]. Locations where the road was in good condition (OR 0.25; 95% CI [0.07, 0.96] and where there was high surveillance from surrounding buildings (OR 0.32; 95% CI [0.13, 0.82] were associated with less severe injuries. These findings could be used by bicyclists and transportation planners to improve safety.

  16. Environmental Determinants of Bicycling Injuries in Alberta, Canada

    Science.gov (United States)

    Romanow, Nicole T. R.; Couperthwaite, Amy B.; McCormack, Gavin R.; Nettel-Aguirre, Alberto; Rowe, Brian H.; Hagel, Brent E.

    2012-01-01

    This study examined environmental risk factors for bicycling injuries, by combining data on bicyclist injuries collected by interviews in the emergency department (ED) with street-level environmental audits of injury locations, capturing path, roadway, safety, land use, and aesthetic characteristics. Cases were bicyclists struck by a motor vehicle (MV) or with severe injuries (hospitalized). Controls were bicyclists who were not hit by a car or those seen and discharged from the ED, matched on time and day of injury. Logistic regression odds ratios (ORs) adjusted for age, sex, peak time, and bicyclist speed with 95% confidence intervals (CIs) were estimated to relate injury risk to environmental characteristics. Factors contributing to MV events included greater traffic volume (OR 5.13; 95% CI [1.44, 18.27]), intersections (OR 6.89; 95% CI [1.48, 32.14]), retail establishments (OR 5.56; 95% CI [1.72, 17.98]), and path obstructions (OR 3.83; 95% CI [1.03, 14.25]). Locations where the road was in good condition (OR 0.25; 95% CI [0.07, 0.96]) and where there was high surveillance from surrounding buildings (OR 0.32; 95% CI [0.13, 0.82]) were associated with less severe injuries. These findings could be used by bicyclists and transportation planners to improve safety. PMID:23251192

  17. The Aeroflex: A Bicycle for Mobile Air Quality Measurements

    Directory of Open Access Journals (Sweden)

    Bart Elen

    2012-12-01

    Full Text Available Fixed air quality stations have limitations when used to assess people's real life exposure to air pollutants. Their spatial coverage is too limited to capture the spatial variability in, e.g., an urban or industrial environment. Complementary mobile air quality measurements can be used as an additional tool to fill this void. In this publication we present the Aeroflex, a bicycle for mobile air quality monitoring. The Aeroflex is equipped with compact air quality measurement devices to monitor ultrafine particle number counts, particulate mass and black carbon concentrations at a high resolution (up to 1 second. Each measurement is automatically linked to its geographical location and time of acquisition using GPS and Internet time. Furthermore, the Aeroflex is equipped with automated data transmission, data pre-processing and data visualization. The Aeroflex is designed with adaptability, reliability and user friendliness in mind. Over the past years, the Aeroflex has been successfully used for high resolution air quality mapping, exposure assessment and hot spot identification. 

  18. On the closure of the extended bicyclic semigroup

    CERN Document Server

    Fihel, Iryna

    2012-01-01

    In the paper we study the semigroup $\\mathscr{C}_{\\mathbb{Z}}$ which is a generalization of the bicyclic semigroup. We describe main algebraic properties of the semigroup $\\mathscr{C}_{\\mathbb{Z}}$ and prove that every non-trivial congruence $\\mathfrak{C}$ on the semigroup $\\mathscr{C}_{\\mathbb{Z}}$ is a group congruence, and moreover the quotient semigroup $\\mathscr{C}_{\\mathbb{Z}}/\\mathfrak{C}$ is isomorphic to a cyclic group. Also we show that the semigroup $\\mathscr{C}_{\\mathbb{Z}}$ as a Hausdorff semitopological semigroup admits only the discrete topology. Next we study the closure $\\operatorname{cl}_T(\\mathscr{C}_{\\mathbb{Z}})$ of the semigroup $\\mathscr{C}_{\\mathbb{Z}}$ in a topological semigroup $T$. We show that the non-empty remainder of $\\mathscr{C}_{\\mathbb{Z}}$ in a topological inverse semigroup $T$ consists of a group of units $H(1_T)$ of $T$ and a two-sided ideal $I$ of $T$ in the case when $H(1_T)\

  19. Bicycle accident-related head injuries in India

    Science.gov (United States)

    Munivenkatappa, Ashok; Devi, Bhagavatula Indira; Gregor, Thomas Issac; Bhat, Dhananjay I.; Kumarsamy, Akhil Deepika; Shukla, Dhaval P.

    2013-01-01

    Objectives: To describe the epidemiology of head injuries sustained due to bicycle accidents in India. Materials and Methods: Data were retrospectively collected over a period of six months (15 May 2011 to 15 November 2011). Demography of patients, Glasgow coma scale (GCS), clinical and imaging findings, and mortality and outcome using Glasgow outcome scale (GOS), Rivermead post-concussion symptom questionnaire (RPCSQ) and Rivermead head injury follow-up questionnaire (RHFUQ), were analyzed. Outcome was assessed by telephonic interview. Results: There were 108 patients (100 males) with mean age of 27.7 years. Seventy-four (68.5%) were from rural areas. Accidents due to vehicular collision accounted for 60 (55.6%) cases. None wore a helmet. The admission GCS was 14-15 in 68.5% cases, 13-3 in 31.5%. The risk of moderate to severe injuries was increased among working laborers (OR = 5), and patients with loss of consciousness (OR = 4). Sixty-three (49%) patients had abnormal computed tomography (CT) findings; most common finding was skull fracture 25 (23.1%). Four patients needed surgery. The GOS assessment at three to six months revealed favorable outcome in 66 patients (61.1%) and death in 8 (7.4%). The common post-concussion symptoms were headache, fatigue, and poor concentration. Conclusion: The majority of hospitalized cyclists were from a rural background and of the lower income group. After three months the majority of patients had good recovery with few persistent concussion symptoms. PMID:24250156

  20. The Aeroflex: A Bicycle for Mobile Air Quality Measurements

    Science.gov (United States)

    Elen, Bart; Peters, Jan; Van Poppel, Martine; Bleux, Nico; Theunis, Jan; Reggente, Matteo; Standaert, Arnout

    2013-01-01

    Fixed air quality stations have limitations when used to assess people's real life exposure to air pollutants. Their spatial coverage is too limited to capture the spatial variability in, e.g., an urban or industrial environment. Complementary mobile air quality measurements can be used as an additional tool to fill this void. In this publication we present the Aeroflex, a bicycle for mobile air quality monitoring. The Aeroflex is equipped with compact air quality measurement devices to monitor ultrafine particle number counts, particulate mass and black carbon concentrations at a high resolution (up to 1 second). Each measurement is automatically linked to its geographical location and time of acquisition using GPS and Internet time. Furthermore, the Aeroflex is equipped with automated data transmission, data pre-processing and data visualization. The Aeroflex is designed with adaptability, reliability and user friendliness in mind. Over the past years, the Aeroflex has been successfully used for high resolution air quality mapping, exposure assessment and hot spot identification. PMID:23262484

  1. Optimization of electric bicycle for youths with disabilities.

    Science.gov (United States)

    Blumenstein, Tobias; Zeitlmann, Hilar; Alves-Pinto, Ana; Turova, Varvara; Lampe, Renée

    2014-01-01

    Cerebral palsy is a group of neurodevelopmental disorders that affect a person's ability to move and to maintain balance and posture. People with cerebral palsy have also perception and space orientation deficits so that special assistance devices should be developed to compensate these handicaps. The objective was to optimize an adapted electric bicycle (E-bike) for youths with neurodevelopmental disorders. An adapted E-bike was provided with ultrasonic sensors that measure distances to objects. If the distance to other objects reduces, an acoustic signal is sent. Additionally, a self-created force plate was fixed on the pedal to evaluate the muscle performances during biking. An experiment with the ultrasound warning system confirmed that acoustic feedback was helpful in avoiding obstacles. The measurement of the blood pressure, the heart frequency and the pedaling force during biking approved that the training condition of the test person can be registered and enables tuning the power of the electric motor to individual requirements. The results demonstrate that an adapted E-bike can be improved to provide better space orientation for people with perceptual disorders and to measure training conditions of patients. Moreover, these enable individual adjustment of the electric motor power to optimize comfort and therapy effect.

  2. Heparin-induced circular dichroism of an achiral, bicyclic species.

    Science.gov (United States)

    Stanley, Floyd E; Warner, Andrew M; McWilliams, Kayla M; Stalcup, Apryll M

    2011-01-01

    Antimalarial drugs have shown potential in suppressing the role of glycosaminoglycans (GAGs) in the pathology of prion protein conformational disorders (e.g. "Mad Cow" disease) by competing for sites of electrostatic interaction. In this study, circular dichroism (CD) and UV/Visible (UV/Vis) absorption spectroscopy techniques were used to investigate the interactions between N-methyl-N'-(7-chloro-4-quinolyl)-1,3-diaminopropane (QD), an achiral, bicyclic compound similar to previously investigated antimalarial drugs, and heparin, a complex GAG that is frequently used as a clinical anticoagulant. Relatively intense heparin-induced CD features were observed for QD and were noted to be radically different from previous studies using related chiral drugs, underscoring the importance of the Pfieffer effect on this and similar heparin research. Additionally, the induced CD for QD was observed to be highly dependent upon drug concentration, heparin concentration, system pH, equilibration time, and ionic strength. These results, in connection with recent work, provide new insight into the nature of the association between GAGs and antimalarial species. PMID:21125690

  3. Bicycle Frame Prediction Techniques with Fuzzy Logic Method

    Directory of Open Access Journals (Sweden)

    Rafiuddin Syam

    2015-03-01

    Full Text Available In general, an appropriate size bike frame would get comfort to the rider while biking. This study aims to predict the simulation system on the bike frame sizes with fuzzy logic. Testing method used is the simulation test. In this study, fuzzy logic will be simulated using Matlab language to test their performance. Mamdani fuzzy logic using 3 variables and 1 output variable intake. Triangle function for the input and output. The controller is designed in the type mamdani with max-min composition and the method deffuzification using center of gravity method. The results showed that height, inseam and Crank Size generating appropriate frame size for the rider associated with comfort. Has a height range between 142 cm and 201 cm. Inseam has a range between 64 cm and 97 cm. Crank has a size range between 175 mm and 180 mm. The simulation results have a range of frame sizes between 13 inches and 22 inches. By using the fuzzy logic can be predicted the size frame of bicycle suitable for the biker.

  4. Fe N-Heterocyclic Carbene Complexes as Promising Photosensitizers.

    Science.gov (United States)

    Liu, Yizhu; Persson, Petter; Sundström, Villy; Wärnmark, Kenneth

    2016-08-16

    The photophysics and photochemistry of transition metal complexes (TMCs) has long been a hot field of interdisciplinary research. Rich metal-based redox processes, together with a high variety in electronic configurations and excited-state dynamics, have rendered TMCs excellent candidates for interconversion between light, chemical, and electrical energies in intramolecular, supramolecular, and interfacial arrangements. In specific applications such as photocatalytic organic synthesis, photoelectrochemical cells, and light-driven supramolecular motors, light absorption by a TMC-based photosensitizer and subsequent excited-state energy or electron transfer constitute essential steps. In this context, TMCs based on rare and expensive metals, such as ruthenium and iridium, are frequently employed as photosensitizers, which is obviously not ideal for large-scale implementation. In the search for abundant and environmentally benign solutions, six-coordinate Fe(II) complexes (Fe(II)L6) have been widely considered as highly desirable alternatives. However, not much success has been achieved due to the extremely short-lived triplet metal-to-ligand charge transfer ((3)MLCT) excited state that is deactivated by low-lying metal-centered (MC) states on a 100 fs time scale. A fundamental strategy to design useful Fe-based photosensitizers is thus to destabilize the MC states relative to the (3)MLCT state by increasing the ligand field strength, with special focus on making eg σ* orbitals on the Fe center energetically less accessible. Previous efforts to directly transplant successful strategies from Ru(II)L6 complexes unfortunately met with limited success in this regard, despite their close chemical kinship. In this Account, we summarize recent promising results from our and other groups in utilizing strongly σ-donating N-heterocyclic carbene (NHC) ligands to make strong-field Fe(II)L6 complexes with significantly extended (3)MLCT lifetimes. Already some of the first

  5. Synthesis and Regioselective Reaction of Some Unsymmetrical Heterocyclic Chalcone Derivatives and Spiro Heterocyclic Compounds as Antibacterial Agents

    OpenAIRE

    El-Hashash, Maher A.; Rizk, Sameh A.; Saad R. Atta-Allah

    2015-01-01

    A number of novel heterocyclic chalcone derivatives can be synthesized by thermal and microwave tools. Treatment of 4-(4-Acetylamino- and/or 4-bromo-phenyl)-4-oxobut-2-enoic acids with hydrogen peroxide in alkaline medium were afforded oxirane derivatives 2. Reaction of the epoxide 2 with 2-amino-5-aryl-1,3,4-thiadiazole derivatives yielded chalcone of imidazo[2,1-b]thiadiazole derivative 4 via two thermal routes. In one pot reaction of 4-bromoacetophenone, diethyloxalate, and 2-amino-5-aryl-...

  6. Innovation and the Interrelatedness of Core Competencies: How Taiwan's Giant Bicycles broke into the US Bicycle Market

    Directory of Open Access Journals (Sweden)

    S. Phineas Upham

    2006-03-01

    Full Text Available I argue that capabilities and barriers to entry are, in certain circumstances, interconnected in such a way that sacrificing one of them can lead to the subsequent vulnerability or erosion of another capability or barrier to entry. I illustrate this through a study of the US bicycle market in the 1980's in general, and Schwinn Corporation and Giant Manufacturing in particular, arguing that both the barriers to entry and the firm capabilities were interrelated. A specific set of decisions by Schwinn had broad and unanticipated effects that went beyond the capacity they explicitly relinquished. In this case manufacturing and distribution were tightly linked in such a way that without some form of tight link between them successful incremental innovation became difficult. Seemingly unrelated capabilities and strengths become mutually reinforcing or interconnected. Instead of being able to choose to add a single capability, or choose to discard one, companies may instead be choosing between sets, groups of interlinked, or patterned capabilities. A seemingly small change may require a major reorganization of other core capabilities that its ostensible status belies.

  7. A molecular mechanical model for N-heterocyclic carbenes.

    Science.gov (United States)

    Gehrke, Sascha; Hollóczki, Oldamur

    2016-08-10

    In this work we present a set of force fields for nine synthetically relevant and/or structurally interesting N-heterocyclic carbenes, including imidazol-, thiazol-, triazol-, imidazolidin-, and pyridine-ylidenes. The bonding parameters were calculated by using a series of geometry optimizations by ab initio methods. For fitting the non-bonding interactions, a water molecule was employed as a probe. The interaction energy between the carbene and the probe molecule was sampled along two coordinates for each carbene, representing the interaction through the lone pair, or the π system of the molecule. The corresponding reference interaction energies were obtained by CCSD(T)/CBS calculations. To describe the direction dependence of the intermolecular potential energy, an extra, massless Coulombic interaction site was included for all carbenes, which represents the lone pair of the divalent carbon atom. The resulting fitted carbene force field (CaFF) showed a robust behavior regarding probe molecule, as changing the molecular mechanical water model, or employing, instead, an OPLS methanol molecule did not introduce significant deviations in the potential energies. The obtained CaFF models are easy to merge with standard OPLS or AMBER force fields, therefore the molecular simulations of a large number of N-heterocyclic carbenes becomes available. PMID:27426687

  8. Synthesis of heterocyclic chalcone derivatives and their radical scavenging ability toward 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals

    International Nuclear Information System (INIS)

    A series of heterocyclic chalcone derivatives bearing heterocycles such as thiophene or furan ring as an isostere of benzene ring were carefully prepared, and the influence of heterocycles on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities was systematically investigated. Structure-activity relationships (SAR) analysis showed that the activities of thiophene ring-containing chalcones were higher than those of furan ring containing chalcones, and the presence of methyl substituent of heterocyclic ring distinctly affected the activities compared with non-substituted heterocycles in an opposite manner, with the 4'-methyl group of thiophene ring increasing activity and the 3'-methyl group of the furan ring decreasing activity. The distinct isosteric effect of heterocycles (i.e., thiophene or furan ring) on radical scavenging activities of heterocyclic chalcones was distinctly demonstrated in our work

  9. Synthesis of heterocyclic chalcone derivatives and their radical scavenging ability toward 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Kijun; Kim, Hoseok; Kim, Beomtae [Research Center of Bioactive Materials, Hwaseong (Korea, Republic of); Han, Incheol [Chonbuk National Univ., Jeonju (Korea, Republic of)

    2012-04-15

    A series of heterocyclic chalcone derivatives bearing heterocycles such as thiophene or furan ring as an isostere of benzene ring were carefully prepared, and the influence of heterocycles on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities was systematically investigated. Structure-activity relationships (SAR) analysis showed that the activities of thiophene ring-containing chalcones were higher than those of furan ring containing chalcones, and the presence of methyl substituent of heterocyclic ring distinctly affected the activities compared with non-substituted heterocycles in an opposite manner, with the 4'-methyl group of thiophene ring increasing activity and the 3'-methyl group of the furan ring decreasing activity. The distinct isosteric effect of heterocycles (i.e., thiophene or furan ring) on radical scavenging activities of heterocyclic chalcones was distinctly demonstrated in our work.

  10. Evaluating the Safety Effects of Bicycle Lanes in New York City

    Science.gov (United States)

    Srinivasan, Raghavan; McKnight, Claire E.; Ewing, Reid; Roe, Matthew

    2012-01-01

    Objectives. We evaluated the effects of on-street bicycle lanes installed prior to 2007 on different categories of crashes (total crashes, bicyclist crashes, pedestrian crashes, multiple-vehicle crashes, and injurious or fatal crashes) occurring on roadway segments and at intersections in New York City. Methods. We used generalized estimating equation methodology to compare changes in police-reported crashes in a treatment group and a comparison group before and after installation of bicycle lanes. Our study approach allowed us to control confounding factors, such as built environment characteristics, that cannot typically be controlled when a comparison group is used. Results. Installation of bicycle lanes did not lead to an increase in crashes, despite the probable increase in the number of bicyclists. The most likely explanations for the lack of increase in crashes are reduced vehicular speeds and fewer conflicts between vehicles and bicyclists after installation of these lanes. Conclusions. Our results indicate that characteristics of the built environment have a direct impact on crashes and that they should thus be controlled in studies evaluating traffic countermeasures such as bicycle lanes. To prevent crashes at intersections, we recommend installation of “bike boxes” and markings that indicate the path of bicycle lanes across intersections. PMID:22095351

  11. The impact response of traditional and BMX-style bicycle helmets at different impact severities.

    Science.gov (United States)

    DeMarco, Alyssa L; Chimich, Dennis D; Gardiner, John C; Siegmund, Gunter P

    2016-07-01

    Bicycle helmets reduce the frequency and severity of severe to fatal head and brain injuries in bicycle crashes. Our goal here was to measure the impact attenuation performance of common bicycle helmets over a range of impact speeds. We performed 127 drop tests using 13 different bicycle helmet models (6 traditional style helmets and 7 BMX-style helmets) at impact speeds ranging from 1 to 10m/s onto a flat anvil. Helmets were struck on their left front and/or right front areas, a common impact location that was at or just below the test line of most bicycle helmet standards. All but one of the 10 certified helmet models remained below the 300g level at an impact speed of 6m/s, whereas none of the 3 uncertified helmets met this criterion. We found that the helmets with expanded polystyrene liners performed similarly and universally well. The single certified helmet with a polyurethane liner performed below the level expected by the Consumer Product Safety Commission (CPSC) standard at our impact location and the helmet structure failed during one of two supplemental tests of this helmet above the test line. Overall, we found that increased liner thickness generally reduced peak headform acceleration, particularly at higher impact speeds. PMID:27077273

  12. Johnson Space Center's Free Range Bicycle Program.- Fall 2015 Intern Report

    Science.gov (United States)

    Lee-Stockton, Willem

    2015-01-01

    NASA's Johnson Space Center is a big place, encompassing 1,620 acres and more than a hundred buildings. Furthermore, there are reportedly 15 thousand employees, all of which have somewhere to be. To facilitate the movement of all these people JSC has historically relied on human power. Pedaling their way towards deep space, bicycles have been the go to method. Currently there are about 200 Free Range Bicycles at JSC. Free Range Bicycles belong to nobody, except NASA, and are available for anybody to use. They are not to be locked or hidden (although frequently are) and the intention is that there will always be a bike to hop on to get where you're going (although it may not be the bike you rode in on). Although not without its own shortcomings, the Free Range Bicycle Program has continued to provide low cost, simple transportation for NASA's JSC. In addition to the approximately 200 Free Range Bicycles, various larger divisions (like engineering) will often buy a few dozen bikes for their team members to use or individuals will bring their own personal bike to either commute or use on site. When these bicycles fall into disrepair or are abandoned (from retirees etc) they become a problem at JSC. They are an eye sore, create a safety hazard and make it harder to find a working bike in a time of need. The Free Range Program hopes to address this first problem by "tagging out" abandoned or out of service bicycles. A bright orange "DO NOT OPERATE" tag is placed on the bike and given a serial number for tracking purposes. See picture to the right. If the bike has an active owner with intentions to repair the bike the bottom of the tag has instructions for how to claim the abandoned bicycle. After being tagged the owner of the bicycle has 30 days to claim the bicycle and either haul it off site or get it repaired (and labeled) in accordance with Johnson's Bicycle Policy. If the abandoned bicycle is not claimed within 30 days it becomes the property of the Government. The

  13. Lateral Drift Behavior Analysis in Mixed Bicycle Traffic: A Cellular Automaton Model Approach

    Directory of Open Access Journals (Sweden)

    Xue Feng

    2016-01-01

    Full Text Available Bicycle movements are always associated with lateral drifts. However, the impacts of lateral drift behavior, as well as variable lateral clearance maintaining behavior due to the variation of drift intensity, on mixed bicycle flow are not clear. This paper establishes a new cellular automata model to study typical characteristics of mixed bicycle traffic induced by lateral drift and its accompanying behavior. Based on derived positive correlation between passing speed and drift speed through survey, the occurrence probability of lateral drift and the degree of maintained lateral clearance are both introduced in accordance with the variance of passing speed. Then, in whole density region, firm conformity between simulation results and actual survey data is reached, which has seldom been achieved in previous studies. It is further verified that speed distortions in intermediate and high density region induced by assumption of constant lateral clearance requirements can be revised by introducing its variability characteristics. In addition, two contrastive impacts of lateral drift behavior are observed. That is, it causes speed fluctuation in low density while alleviating the speed fluctuation in relatively high density. These results are expected to be helpful to improve the simulation performance of mixed bicycle flow as well as depict more realistic vehicle-bicycle conflicts and so on.

  14. Heterocyclic aramid nanoparticle-assisted graphene exfoliation for fabrication of pristine graphene-based composite paper

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Yao; Liu, Qi; Fan, Jinchen, E-mail: Jinchen.fan@shiep.edu.cn; Shi, Penghui; Min, Yulin, E-mail: ahaqmylin@126.com; Xu, Qunjie [Shanghai University of Electric Power, Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, College of Environmental and Chemical Engineering (China)

    2015-07-15

    Mechanically strong, electrically conductive, and flexible pristine graphene-based composite paper was prepared based on heterocyclic aramid nanoparticle-assisted liquid-phase exfoliation of graphite. The macroscopic heterocyclic aramid yarns were split and assembled into heterocyclic aramid nanoparticles with the size of ∼30 nm by deprotonation in dimethylsulfoxide in the presence of potassium hydroxide. The obtained heterocyclic aramid nanoparticles dimethylsulfoxide dispersion was used as good medium solvent for highly efficiency liquid-phase exfoliation of graphite. The results demonstrated that the concentration of exfoliated graphene can facile reaches ∼2.72 mg/mL after direct sonication of 7 h with assist of heterocyclic aramid nanoparticles. After exfoliation, the self-assembled pristine graphene-based composite paper was fabricated by vacuum-assisted filtration. Due to the introduction of heterocyclic aramid nanoparticles, the self-assembled pristine graphene/heterocyclic aramid nanoparticles composite paper exhibited good mechanical property with tensile strength of ∼129.7 MPa, meantime, has a high electrical conductivity of ∼1.42 × 10{sup 4} S/m.

  15. Heterocyclic aramid nanoparticle-assisted graphene exfoliation for fabrication of pristine graphene-based composite paper

    International Nuclear Information System (INIS)

    Mechanically strong, electrically conductive, and flexible pristine graphene-based composite paper was prepared based on heterocyclic aramid nanoparticle-assisted liquid-phase exfoliation of graphite. The macroscopic heterocyclic aramid yarns were split and assembled into heterocyclic aramid nanoparticles with the size of ∼30 nm by deprotonation in dimethylsulfoxide in the presence of potassium hydroxide. The obtained heterocyclic aramid nanoparticles dimethylsulfoxide dispersion was used as good medium solvent for highly efficiency liquid-phase exfoliation of graphite. The results demonstrated that the concentration of exfoliated graphene can facile reaches ∼2.72 mg/mL after direct sonication of 7 h with assist of heterocyclic aramid nanoparticles. After exfoliation, the self-assembled pristine graphene-based composite paper was fabricated by vacuum-assisted filtration. Due to the introduction of heterocyclic aramid nanoparticles, the self-assembled pristine graphene/heterocyclic aramid nanoparticles composite paper exhibited good mechanical property with tensile strength of ∼129.7 MPa, meantime, has a high electrical conductivity of ∼1.42 × 104 S/m.

  16. Bicycle accident-related head injuries in India

    Directory of Open Access Journals (Sweden)

    Ashok Munivenkatappa

    2013-01-01

    Full Text Available Objectives: To describe the epidemiology of head injuries sustained due to bicycle accidents in India. Materials and Methods: Data were retrospectively collected over a period of six months (15 May 2011 to 15 November 2011. Demography of patients, Glasgow coma scale (GCS, clinical and imaging findings, and mortality and outcome using Glasgow outcome scale (GOS, Rivermead post-concussion symptom questionnaire (RPCSQ and Rivermead head injury follow-up questionnaire (RHFUQ, were analyzed. Outcome was assessed by telephonic interview. Results: There were 108 patients (100 males with mean age of 27.7 years. Seventy-four (68.5% were from rural areas. Accidents due to vehicular collision accounted for 60 (55.6% cases. None wore a helmet. The admission GCS was 14-15 in 68.5% cases, 13-3 in 31.5%. The risk of moderate to severe injuries was increased among working laborers (OR = 5, and patients with loss of consciousness (OR = 4. Sixty-three (49% patients had abnormal computed tomography (CT findings; most common finding was skull fracture 25 (23.1%. Four patients needed surgery. The GOS assessment at three to six months revealed favorable outcome in 66 patients (61.1% and death in 8 (7.4%. The common post-concussion symptoms were headache, fatigue, and poor concentration. Conclusion: The majority of hospitalized cyclists were from a rural background and of the lower income group. After three months the majority of patients had good recovery with few persistent concussion symptoms.

  17. Synthetic strategy for bicyclic tetrapeptides HDAC inhibitors using ring closing metathesis

    Indian Academy of Sciences (India)

    Md Nurul Islam; Md Shahidul Islam; Md Ashraful Hoque; Tamaki Kato; Norikazu Nishino

    2015-09-01

    Cyclic peptides show diverse biological activities and are considered as good therapeutic agents due to structural rigidity, receptor selectivity and biochemical stability. We have developed bicyclic tetrapeptide HDAC inhibitors based on different cyclic tetrapeptide scaffolds. For the synthesis of these bicyclic tetrapeptides, two cyclization steps, namely, peptide cyclization and fusion of aliphatic side chains by ring closing metathesis (RCM) were involved. In the course of these syntheses, we have established two facts: a lower limit of aliphatic loop length and better synthetic route for bicyclic tetrapeptide synthesis. It was found that nine methylene loop length is the lower limit for aliphatic loop and the synthetic route selection depended on the configuration of amino acids in the cyclic tetrapeptide scaffold. RCM followed by peptide cyclization was the proper route for LDLD configuration and the reverse route was suitable for LLLD configuration.

  18. Conversion Of An Ordinary N Bicycle Into An Electric Bike And Related Research

    Directory of Open Access Journals (Sweden)

    Marius Janavičius

    2014-05-01

    Full Text Available An electric bicycle as a transport and leisure vehicle is expected to have a promising future. Currently, he market offers a great choice of factory electric bicycles and conversion kits to remake an ordinary bicycle into an electric bike. Also, the increasing number of electric vehicles is determined by the reduction in costs for manufacturing of batteries and an evolution in battery technology. This article presents the implementation of an electric bike by selecting the “Golden Motor Technology” company’s electric front wheel conversion kit MagicPie3 and 16 cell 10Ah LiFePO4 battery. After installation of the engine and other components, experiments were conducted to evaluate the performance characteristics of the electric bike and check the manufacturer’s specifications.

  19. Study of the health effects of bicycling in an urban atmosphere. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Waldman, M.; Weiss, S.; Articola, W.

    1977-10-14

    This report analyzes data on the health effects of bicycling in an urban environment through intensive study of ten healthy male subjects bicycling or driving in systematically varied conditions in the streets of Washington, D.C. Evaluation criteria for available technology and instrumentation are included and a methodology is developed for route selection. Specific air pollutants (carbon monoxide, ozone, sulfates, nitrates, and particulates) are measured concurrently with exposure and subsequent changes in health status identified through pulmonary function testing, cardiovascular testing, and blood and symptoms analysis. The report concludes that no major adverse short-term health effects were noted for ten healthy male subjects while bicycling or driving in levels of pollution and thermal stress encountered during the study period. Recommendations for further research are also presented.

  20. Association between neighborhood walkability and GPS-measured walking, bicycling and vehicle time in adolescents

    DEFF Research Database (Denmark)

    Carlson, Jordan A.; Saelens, Brian E.; Kerr, Jacqueline;

    2015-01-01

    Objectives: To investigate relations of walking, bicycling and vehicle time to neighborhood walkability and total physical activity in youth. Methods: Participants (N=690) were from 380 census block groups of high/low walkability and income in two US regions. Home neighborhood residential density......, intersection density, retail density, entertainment density and walkability were derived using GIS. Minutes/day of walking, bicycling and vehicle time were derived from processing algorithms applied to GPS. Accelerometers estimated total daily moderate-to-vigorous physical activity (MVPA). Models were adjusted...... for nesting of days (N=2987) within participants within block groups. Results: Walking occurred on 33%, active travel on 43%, and vehicle time on 91% of the days observed. Intersection density and neighborhood walkability were positively related to walking and bicycling and negatively related to vehicle time...

  1. The spatio-temporal Development of Copenhagen's bicycle infrastructure 1912-2013

    DEFF Research Database (Denmark)

    Carstensen, Trine Agervig; Olafsson, Anton Stahl; Bech, Nynne Marie;

    2015-01-01

    Cycling plays an important role in low-carbon transitions. Around the globe, cities are constructing bicycle infrastructure. The city of Copenhagen has a bicycle-friendly infrastructure celebrated for its fine-meshed network. This study documents the spatio-temporal development of Copenhagen....... In search for identifying drivers, the study analyses the city’s spatial growth pattern, migration pattern, development of road network and changes in the transport culture. Analyses reveal that the bicycle infrastructure expanded at a relatively constant pace during distinct periods of urban transformation...... and safety (first cycling city); the flow for cars (car city); urban liveability for soft transport (liveable city); and, finally, to improve the flow for cyclists as part a strategic re-design of urban space (liveable cycling city)....

  2. The effects of operating a touch screen smartphone and other common activities performed while bicycling on cycling behaviour

    NARCIS (Netherlands)

    de Waard, Dick; Lewis Evans, Ben; Jelijs, Bart; Tucha, Oliver; Brookhuis, Karel

    2014-01-01

    Although it has been shown that making phone calls or sending text messages while riding a bicycle can have a negative impact on bicyclist’s behaviour, in countries such as the Netherlands the operation of a mobile phone while cycling on a bicycle is not illegal and is actually quite common. In rece

  3. The role of bicycle sharing systems in normalising the image of cycling: An observational study of London cyclists

    Science.gov (United States)

    Goodman, Anna; Green, Judith; Woodcock, James

    2014-01-01

    Bicycle sharing systems are increasingly popular around the world and have the potential to increase the visibility of people cycling in everyday clothing. This may in turn help normalise the image of cycling, and reduce perceptions that cycling is ‘risky’ or ‘only for sporty people’. This paper sought to compare the use of specialist cycling clothing between users of the London bicycle sharing system (LBSS) and cyclists using personal bicycles. To do this, we observed 3594 people on bicycles at 35 randomly-selected locations across central and inner London. The 592 LBSS users were much less likely to wear helmets (16% vs. 64% among personal-bicycle cyclists), high-visibility clothes (11% vs. 35%) and sports clothes (2% vs. 25%). In total, 79% of LBSS users wore none of these types of specialist cycling clothing, as compared to only 30% of personal-bicycle cyclists. This was true of male and female LBSS cyclists alike (all p>0.25 for interaction). We conclude that bicycle sharing systems may not only encourage cycling directly, by providing bicycles to rent, but also indirectly, by increasing the number and diversity of cycling ‘role models’ visible. PMID:25568838

  4. Outcomes of Home-Support Consultation on the Maintenance of Bicycle-Riding Skills for Youth with Autism Spectrum Disorder

    Science.gov (United States)

    Reynolds, Jennifer L.; Pitchford, E. Andrew; Hauck, Janet L.; Ketcheson, Leah R.; Ulrich, Dale A.

    2016-01-01

    Bicycle riding is a functional motor skill that increases physical activity opportunities, social interaction, and independence. However, bicycle riding is difficult for youth with autism spectrum disorder (ASD) to learn. This study examined the effectiveness of home-support consultation (HSC) on increasing the maintenance of independent bicycle…

  5. Perceiving and Acting on Complex Affordances: How Children and Adults Bicycle across Two Lanes of Opposing Traffic

    Science.gov (United States)

    Grechkin, Timofey Y.; Chihak, Benjamin J.; Cremer, James F.; Kearney, Joseph K.; Plumert, Jodie M.

    2013-01-01

    This investigation examined how children and adults negotiate a challenging perceptual-motor problem with significant real-world implications--bicycling across two lanes of opposing traffic. Twelve- and 14-year-olds and adults rode a bicycling simulator through an immersive virtual environment. Participants crossed intersections with continuous…

  6. Synthesis of a Library of 1,5,2-Dithiazepine 1,1-Dioxides. Part 2: Routes to Bicyclic Sultams

    Science.gov (United States)

    Zang, Qin; Javed, Salim; Zhou, Aihua; Knudtson, Chris A.; Bi, Danse; Basha, Fatima Z.; Hanson, Paul R.

    2013-01-01

    The synthesis of a library of bicyclic sultams incorporating the 1,5,2-dithiazepine 1,1-dioxide moiety is reported. Following scaffold synthesis via a one-pot sulfonylation/intramolecular thia-Michael protocol, several additional cyclization strategies have been realized enabling access to new bicyclic sultams. PMID:24385680

  7. Orthogonal ring-closing alkyne and olefin metathesis for the synthesis of small GTPase-targeting bicyclic peptides.

    Science.gov (United States)

    Cromm, Philipp M; Schaubach, Sebastian; Spiegel, Jochen; Fürstner, Alois; Grossmann, Tom N; Waldmann, Herbert

    2016-01-01

    Bicyclic peptides are promising scaffolds for the development of inhibitors of biological targets that proved intractable by typical small molecules. So far, access to bioactive bicyclic peptide architectures is limited due to a lack of appropriate orthogonal ring-closing reactions. Here, we report chemically orthogonal ring-closing olefin (RCM) and alkyne metathesis (RCAM), which enable an efficient chemo- and regioselective synthesis of complex bicyclic peptide scaffolds with variable macrocycle geometries. We also demonstrate that the formed alkyne macrocycle can be functionalized subsequently. The orthogonal RCM/RCAM system was successfully used to evolve a monocyclic peptide inhibitor of the small GTPase Rab8 into a bicyclic ligand. This modified peptide shows the highest affinity for an activated Rab GTPase that has been reported so far. The RCM/RCAM-based formation of bicyclic peptides provides novel opportunities for the design of bioactive scaffolds suitable for the modulation of challenging protein targets. PMID:27075966

  8. Orthogonal ring-closing alkyne and olefin metathesis for the synthesis of small GTPase-targeting bicyclic peptides.

    Science.gov (United States)

    Cromm, Philipp M; Schaubach, Sebastian; Spiegel, Jochen; Fürstner, Alois; Grossmann, Tom N; Waldmann, Herbert

    2016-04-14

    Bicyclic peptides are promising scaffolds for the development of inhibitors of biological targets that proved intractable by typical small molecules. So far, access to bioactive bicyclic peptide architectures is limited due to a lack of appropriate orthogonal ring-closing reactions. Here, we report chemically orthogonal ring-closing olefin (RCM) and alkyne metathesis (RCAM), which enable an efficient chemo- and regioselective synthesis of complex bicyclic peptide scaffolds with variable macrocycle geometries. We also demonstrate that the formed alkyne macrocycle can be functionalized subsequently. The orthogonal RCM/RCAM system was successfully used to evolve a monocyclic peptide inhibitor of the small GTPase Rab8 into a bicyclic ligand. This modified peptide shows the highest affinity for an activated Rab GTPase that has been reported so far. The RCM/RCAM-based formation of bicyclic peptides provides novel opportunities for the design of bioactive scaffolds suitable for the modulation of challenging protein targets.

  9. Risky riding: Naturalistic methods comparing safety behavior from conventional bicycle riders and electric bike riders.

    Science.gov (United States)

    Langford, Brian Casey; Chen, Jiaoli; Cherry, Christopher R

    2015-09-01

    As electric bicycles (e-bikes) have emerged as a new transportation mode, their role in transportation systems and their impact on users have become important issues for policy makers and engineers. Little safety-related research has been conducted in North America or Europe because of their relatively small numbers. This work describes the results of a naturalistic GPS-based safety study between regular bicycle (i.e., standard bicycle) and e-bike riders in the context of a unique bikesharing system that allows comparisons between instrumented bike technologies. We focus on rider safety behavior under four situations: (1) riding in the correct direction on directional roadway segments, (2) speed on on-road and shared use paths, (3) stopping behavior at stop-controlled intersections, and (4) stopping behavior at signalized intersections. We find that, with few exceptions, riders of e-bike behave very similarly to riders of bicycles. Violation rates were very high for both vehicles. Riders of regular bicycles and e-bikes both ride wrong-way on 45% and 44% of segments, respectively. We find that average on-road speeds of e-bike riders (13.3kph) were higher than regular bicyclists (10.4kph) but shared use path (greenway) speeds of e-bike riders (11.0kph) were lower than regular bicyclists (12.6kph); both significantly different at >95% confidence. At stop control intersections, both bicycle and e-bike riders violate the stop signs at the similar rate with bicycles violating stop signs at a slightly higher rate at low speed thresholds (∼80% violations at 6kph, 40% violations at 11kph). Bicycles and e-bikes violate traffic signals at similar rates (70% violation rate). These findings suggest that, among the same population of users, e-bike riders exhibit nearly identical safety behavior as regular bike riders and should be regulated in similar ways. Users of both technologies have very high violation rates of traffic control devices and interventions should occur to

  10. The Feasibility of Wood and its Derivatives as a Bicycle Frame Building Material

    OpenAIRE

    BRENT TAYLOR, NICHOLAS

    2016-01-01

    [EN] ABSTRACT Nicholas Brent Taylor: The Feasibility of Wood and its Derivatives as a Bicycle Frame Building Material The bicycle is often considered as one of the most important inventions of all time. In addition, it is the most efficient form of human transport in the world. It is non pollutant, uses no fuel other than human power and its carbon footprint is neutralised in a short time. Today, faced with the threat of global warming brought about by fossil fuels, countries such as De...

  11. Device and method to determine perineal artery occlusion during road bicycling.

    Science.gov (United States)

    Parthiban, Sujeeth; Hotaling, James M; Ohlander, Samuel J; Baftiri, Amit P; Freels, Sally; Niederberger, Craig S

    2014-01-01

    Greater than 60 million American men who ride bicycles are at risk of developing erectile dysfunction. One possible reason is occlusion of the perineal arteries. Researchers relied on indirect methods and stationary models to study this problem. We developed a novel system to quantify occlusion among bicycle riders during a road bike ride. Our verification and validation activities show that this system can be safely used on human subjects to measure perineal artery occlusion. The method described in this paper provides a valuable tool to the researchers to study or to develop new solutions that alleviate this problem. The outcomes of these efforts will help millions of cyclists worldwide. PMID:25570811

  12. Pharmacokinetics-Pharmacodynamics Analysis of Bicyclic 4-Nitroimidazole Analogs in a Murine Model of Tuberculosis

    OpenAIRE

    Lakshminarayana, Suresh B.; Helena I M Boshoff; Joseph Cherian; Sindhu Ravindran; Anne Goh; Jan Jiricek; Mahesh Nanjundappa; Amit Nayyar; Meera Gurumurthy; Ramandeep Singh; Thomas Dick; Francesca Blasco; Barry, Clifton E.; Ho, Paul C.; Manjunatha, Ujjini H

    2014-01-01

    PA-824 is a bicyclic 4-nitroimidazole, currently in phase II clinical trials for the treatment of tuberculosis. Dose fractionation pharmacokinetic-pharmacodynamic studies in mice indicated that the driver of PA-824 in vivo efficacy is the time during which the free drug concentrations in plasma are above the MIC (fT>MIC ). In this study, a panel of closely related potent bicyclic 4-nitroimidazoles was profiled in both in vivo PK and efficacy studies. In an established murine TB model, the eff...

  13. Mapping cyclist activity and injury risk in a network combining smartphone GPS data and bicycle counts.

    Science.gov (United States)

    Strauss, Jillian; Miranda-Moreno, Luis F; Morency, Patrick

    2015-10-01

    In recent years, the modal share of cycling has been growing in North American cities. With the increase of cycling, the need of bicycle infrastructure and road safety concerns have also raised. Bicycle flows are an essential component in safety analysis. The main objective of this work is to propose a methodology to estimate and map bicycle volumes and cyclist injury risk throughout the entire network of road segments and intersections on the island of Montreal, achieved by combining smartphone GPS traces and count data. In recent years, methods have been proposed to estimate average annual daily bicycle (AADB) volume and injury risk estimates at both the intersection and segment levels using bicycle counts. However, these works have been limited to small samples of locations for which count data is available. In this work, a methodology is proposed to combine short- and long-term bicycle counts with GPS data to estimate AADB volumes along segments and intersections in the entire network. As part of the validation process, correlation is observed between AADB values obtained from GPS data and AADB values from count data, with R-squared values of 0.7 for signalized intersections, 0.58 for non-signalized intersections and between 0.48 and 0.76 for segments with and without bicycle infrastructure. The methodology is also validated through the calibration of safety performance functions using both sources of AADB estimates, from counts and from GPS data. Using the validated AADB estimates, the factors associated with injury risk were identified using data from the entire population of intersections and segments throughout Montreal. Bayesian injury risk maps are then generated and the concentrations of expected injuries and risk at signalized intersections are identified. Signalized intersections, which are often located at the intersection of major arterials, witness 4 times more injuries and 2.5 times greater risk than non-signalized intersections. A similar

  14. Bicycle-related genitourinary injuries in the USA from 2002–2010

    Science.gov (United States)

    Tasian, Gregory E; Appa, Ayesha A; Bagga, Herman S; Blaschko, Sarah; McCulloch, Charles E; McAninch, Jack W; Breyer, Benjamin N

    2014-01-01

    Among children, the incidence of bicycle-related genitourinary (GU) injuries was 448 per 100 000 (95% CI 383 to 514) and, among adults, was 53 per 100 000 (95% CI 36 to 71). Although children sustained more injuries, adults were more likely to being admitted to the hospital for the GU injury (OR 1.95, 95% CI 1.13 to 3.37). Children sustain nearly 10 times more GU injuries due to bicycles than adults, but adults have higher odds of sustaining injuries requiring admission. PMID:24618096

  15. Risky riding: Naturalistic methods comparing safety behavior from conventional bicycle riders and electric bike riders.

    Science.gov (United States)

    Langford, Brian Casey; Chen, Jiaoli; Cherry, Christopher R

    2015-09-01

    As electric bicycles (e-bikes) have emerged as a new transportation mode, their role in transportation systems and their impact on users have become important issues for policy makers and engineers. Little safety-related research has been conducted in North America or Europe because of their relatively small numbers. This work describes the results of a naturalistic GPS-based safety study between regular bicycle (i.e., standard bicycle) and e-bike riders in the context of a unique bikesharing system that allows comparisons between instrumented bike technologies. We focus on rider safety behavior under four situations: (1) riding in the correct direction on directional roadway segments, (2) speed on on-road and shared use paths, (3) stopping behavior at stop-controlled intersections, and (4) stopping behavior at signalized intersections. We find that, with few exceptions, riders of e-bike behave very similarly to riders of bicycles. Violation rates were very high for both vehicles. Riders of regular bicycles and e-bikes both ride wrong-way on 45% and 44% of segments, respectively. We find that average on-road speeds of e-bike riders (13.3kph) were higher than regular bicyclists (10.4kph) but shared use path (greenway) speeds of e-bike riders (11.0kph) were lower than regular bicyclists (12.6kph); both significantly different at >95% confidence. At stop control intersections, both bicycle and e-bike riders violate the stop signs at the similar rate with bicycles violating stop signs at a slightly higher rate at low speed thresholds (∼80% violations at 6kph, 40% violations at 11kph). Bicycles and e-bikes violate traffic signals at similar rates (70% violation rate). These findings suggest that, among the same population of users, e-bike riders exhibit nearly identical safety behavior as regular bike riders and should be regulated in similar ways. Users of both technologies have very high violation rates of traffic control devices and interventions should occur to

  16. Relationship between Locations of Facial Injury and the Use of Bicycle Helmets: A Systematic Review.

    Science.gov (United States)

    Hwang, Kun; Jeon, Yun Moon; Ko, Yeong Seung; Kim, Yeon Soo

    2015-07-01

    The aim of this study is to review the protective effect of a bicycle helmet on each facial location systematically. PubMed was searched for articles published before December 12, 2014. The data were summarized, and the odds ratio (OR) between the locations of facial injury was calculated. A statistical analysis was performed with Review Manager (The Nordic Cochrane Centre). Bicycle helmets protect the upper and middle face from serious facial injury but do not protect the lower face. Non-wearers had significantly increased risks of upper facial injury (OR, 2.07; Pchin cap might decrease the risk of lower facial injury.

  17. Aminocyclopentanols as sugar mimics. Synthesis from unsaturated bicyclic lactones by Overman rearrangement

    DEFF Research Database (Denmark)

    Bøjstrup, Marie; Fanefjord, Mette; Lundt, Inge

    2007-01-01

    Bicyclic cyclopentane lactones, prepared from bromodeoxyaldonolactones, were transformed into aminocyclopentanols with an Overman rearrangement as the key step. Two of the compounds prepared, 7 and 19, were found to be good inhibitors of jack bean alpha-mannosidase and beta-D-N-acetylglucosaminid......Bicyclic cyclopentane lactones, prepared from bromodeoxyaldonolactones, were transformed into aminocyclopentanols with an Overman rearrangement as the key step. Two of the compounds prepared, 7 and 19, were found to be good inhibitors of jack bean alpha-mannosidase and beta...

  18. Knights of death: introducing bicycles and motor vehicles to Turin, 1890-1907.

    Science.gov (United States)

    Moraglio, Massimo

    2015-04-01

    The aim of this article is to investigate, through a case study from the city of Turin, the reaction to the arrival of bicycles and automobiles in Italy. It focuses on the early years of bicycle and automobile use, using municipal council minutes, local newspapers, and satirical magazines as sources. The introduction of velocipedes and cars disrupted the traditional use of roads as public spaces, generating protests against the new transport devices, especially with regard to safety concerns resulting from the transgression of traditional uses of urban streets, the speed of vehicles, and the anonymity of riders and drivers. PMID:26005084

  19. Continuous-Flow N-Heterocyclic Carbene Generation and Organocatalysis.

    Science.gov (United States)

    Di Marco, Lorenzo; Hans, Morgan; Delaude, Lionel; Monbaliu, Jean-Christophe M

    2016-03-18

    Two methods were assessed for the generation of common N-heterocyclic carbenes (NHCs) from stable imidazol(in)ium precursors using convenient and straightforward continuous-flow setups with either a heterogeneous inorganic base (Cs2 CO3 or K3 PO4 ) or a homogeneous organic base (KN(SiMe3 )2 ). In-line quenching with carbon disulfide revealed that the homogeneous strategy was most efficient for the preparation of a small library of NHCs. The generation of free nucleophilic carbenes was next telescoped with two benchmark NHC-catalyzed reactions; namely, the transesterification of vinyl acetate with benzyl alcohol and the amidation of N-Boc-glycine methyl ester with ethanolamine. Both organocatalytic transformations proceeded with total conversion and excellent yields were achieved after extraction, showcasing the first examples of continuous-flow organocatalysis with NHCs. PMID:26880372

  20. Highly sulfurated heterocycles via dithiiranes and trithietanes as key intermediates

    DEFF Research Database (Denmark)

    Mloston, Gregorz; Majchrazak, Agnieszka; Senning, Alexander Erich Eugen;

    2002-01-01

    2,2,4,4-Tetramethyl-3-thioxocyclobutanone (8b) easily reacts with gaseous chlorine to yield the stable alpha-chloro sulfenyl chloride 10. The same product was obtained when 8b was treated either with phosphorus pentachloride (PCl5) or sulfuryl chloride (SO2Cl2) in CCl4 solution. Sulfur dichloride...... thiosulfenyl chloride 12 added to adamantanethione (8e) yielded the unsymmetrical trisulfide 13c. When 12 was treated with thioacetic acid, the acetylated trisulfide 17 was formed in high yield. "Unzipping" reactions with the acetylated disulfide 16 and trisulfide 17 with morpholine in THF at -40 degreesC led...... to the formation of mixtures of two sulfur-rich heterocycles identified as the pentathiepane 6b and the hexathiepane 7b. A mixture of analogous products was obtained when alpha-chloro sulfenyl chloride 10 was treated with sodium sulfide in anhydrous THF at -40 degreesC. The formation of 6b and 7b is believed...

  1. Synthesis and antimicrobial activity of some novel fused heterocyclic moieties

    Directory of Open Access Journals (Sweden)

    Nareshvarma Seelam

    2013-06-01

    Full Text Available Since the discovery of heterocyclic moieties the chemistry of 1,3,4-thiadiazole and their fused compounds continue to draw attention of organic chemists due to their various biological activities. Here a new class of 1, 3, 4-thiadiazoles which are incorporating with isoxazolo-thiazole moieties were synthesized by the reaction of chalcone derivatives of [ 1, 3, 4 ] thiadiazol-2-yl-thiazolidin-4-one with hydroxylamine hydrochloride. The chemical structures of these compounds were confirmed by IR, NMR ( 1H & 13C and mass spectral studies. The new synthesized compounds were evaluated for their antimicrobial activity. The final results revealed that some of the compounds were exhibited well antimicrobial activity compared to the standard drugs.

  2. Lactoperoxidase-catalyzed activation of carcinogenic aromatic and heterocyclic amines.

    Science.gov (United States)

    Gorlewska-Roberts, Katarzyna M; Teitel, Candee H; Lay, Jackson O; Roberts, Dean W; Kadlubar, Fred F

    2004-12-01

    Lactoperoxidase, an enzyme secreted from the human mammary gland, plays a host defensive role through antimicrobial activity. It has been implicated in mutagenic and carcinogenic activation in the human mammary gland. The potential role of heterocyclic and aromatic amines in the etiology of breast cancer led us to examination of the lactoperoxidase-catalyzed activation of the most commonly studied arylamine carcinogens: 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP), benzidine, 4-aminobiphenyl (ABP), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx). In vitro activation was performed with lactoperoxidase (partially purified from bovine milk or human milk) in the presence of hydrogen peroxide and calf thymus DNA. Products formed during enzymatic activation were monitored by HPLC with ultraviolet and radiometric detection. Two of these products were characterized as hydrazo and azo derivatives by means of mass spectrometry. The DNA binding level of 3H- and 14C-radiolabeled amines after peroxidase-catalyzed activation was dependent on the hydrogen peroxide concentration, and the highest levels of carcinogen binding to DNA were observed at 100 microM H2O2. Carcinogen activation and the level of binding to DNA were in the order of benzidine > ABP > IQ > MeIQx > PhIP. One of the ABP adducts was identified, and the level at which it is formed was estimated to be six adducts/10(5) nucleotides. The susceptibility of aromatic and heterocyclic amines for lactoperoxidase-catalyzed activation and the binding levels of activated products to DNA suggest a potential role of lactoperoxidase-catalyzed activation of carcinogens in the etiology of breast cancer.

  3. Chemistry and adhesive properties of poly(arylene ether)s containing heterocyclic units

    Science.gov (United States)

    Connell, John W.

    1991-01-01

    Novel poly(arylene ether)s containing heterocyclic units were prepared, characterized, and evaluated as adhesives and composite matrices. The polymers were prepared by reacting a heterocyclic bisphenol with an activated aromatic dihalide in a polar aprotic solvent, using potassium carbonate. The polymerizations were generally carried out in N,N-dimethylacetamide at 155 C. In some cases, where the polymers were semicrystalline, higher temperatures and thus higher boiling solvents were necessary to keep the polymers in solution. Heterocyclic rings incorporated into the poly(arylene ether) backbone include phenylquinoxaline, phenylimidazole, benzimidazole, benzoxazole, 1,3,4-oxadiazole, and 1,2,4-triazole. The polymers were characterized by differential scanning calorimetry, solution viscosity, X-ray diffraction, thin film, and adhesive and (in some cases) composite properties. The glass transition temperatures, crystalline melt temperature, solubility, and mechanical properties varied depending upon the heterocyclic ring. The chemistry and properties of these materials are discussed.

  4. Physicochemical Mechanisms of Synergistic Biological Action of Combinations of Aromatic Heterocyclic Compounds

    Directory of Open Access Journals (Sweden)

    Maxim P. Evstigneev

    2013-01-01

    Full Text Available The mechanisms of synergistic biological effects observed in the simultaneous use of aromatic heterocyclic compounds in combination are reviewed, and the specific biological role of heteroassociation of aromatic molecules is discussed.

  5. Probing the orthosteric binding site of GABAA receptors with heterocyclic GABA carboxylic acid bioisosteres

    DEFF Research Database (Denmark)

    Petersen, Jette G; Bergmann, Rikke; Krogsgaard-Larsen, Povl;

    2013-01-01

    the orthosteric binding site. The physicochemical properties of the heterocyclic moieties making them suitable for bioisosteric replacement of the carboxylic acid in the molecule of GABA are discussed. A variety of synthetic strategies for synthesis of the heterocyclic scaffolds are available. Likewise, methods...... for introduction of substituents into specific positions of the heterocyclic scaffolds facilitate the investigation of different regions in the orthosteric binding pocket in close vicinity of the core scaffolds of muscimol/GABA. The development of structural models, from pharmacophore models to receptor homology...... models, has provided more insight into the molecular basis for binding. Similar binding modes are proposed for the heterocyclic GABA analogues covered in this review by use of ligand-receptor docking into the receptor homology model and the presented structure-activity relationships. A network...

  6. Microwave-Assisted Synthesis of Bio-Active Heterocycles and Fine Chemicals in Aqueous Media

    Science.gov (United States)

    Human health, especially in the aging population, mostly depends on various medicines, and researchers are combating against emerging diseases by new drug discovery. Heterocyclic compounds hold a special place among pharmaceutically active natural products as well as synthetic co...

  7. Impregnated palladium on magnetite as catalyst for direct arylation of heterocycles

    OpenAIRE

    Cano Monserrat, Rafael; Pérez Galera, Juana María; Ramón Dangla, Diego José; McGlacken, Gerard P.

    2016-01-01

    Palladium impregnated on magnetite is an efficient, cheap and easy to prepare catalyst for the direct arylation of heterocycles. Good yields are afforded under relatively mild conditions and a broad substrate scope is evident. The catalyst is regioselective in many cases, affording arylated products, at the C2- or C3-position (depending of the heterocycle used). The methodology can be extended to prepare chromenes through an intramolecular direct arylation reaction. Some evidence is provided ...

  8. An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

    OpenAIRE

    Nikzad Nikbin; Ley, Steven V.; Ian R. Baxendale; Marcus Baumann

    2011-01-01

    This review presents a comprehensive overview on selected synthetic routes towards commercial drug compounds as published in both journal and patent literature. Owing to the vast number of potential structures, we have concentrated only on those drugs containing five-membered heterocycles and focused principally on the assembly of the heterocyclic core. In order to target the most representative chemical entities the examples discussed have been selected from the top 200 best selling drugs of...

  9. An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

    Directory of Open Access Journals (Sweden)

    Nikzad Nikbin

    2011-04-01

    Full Text Available This review presents a comprehensive overview on selected synthetic routes towards commercial drug compounds as published in both journal and patent literature. Owing to the vast number of potential structures, we have concentrated only on those drugs containing five-membered heterocycles and focused principally on the assembly of the heterocyclic core. In order to target the most representative chemical entities the examples discussed have been selected from the top 200 best selling drugs of recent years.

  10. Selective Access to Heterocyclic Sulfonamides and Sulfonyl Fluorides via a Parallel Medicinal Chemistry Enabled Method.

    Science.gov (United States)

    Tucker, Joseph W; Chenard, Lois; Young, Joseph M

    2015-11-01

    A sulfur-functionalized aminoacrolein derivative is used for the efficient and selective synthesis of heterocyclic sulfonyl chlorides, sulfonyl fluorides, and sulfonamides. The development of a 3-step parallel medicinal chemistry (PMC) protocol for the synthesis of pyrazole-4-sulfonamides effectively demonstrates the utility of this reagent. This reactivity was expanded to provide rapid access to other heterocyclic sulfonyl fluorides, including pyrimidines and pyridines, whose corresponding sulfonyl chlorides lack suitable chemical stability.

  11. N-heterocyclic carbene catalyzed synthesis of dimethyl carbonate via transesterification of ethylene carbonate with methanol

    Directory of Open Access Journals (Sweden)

    Guang-Fen Du

    2015-01-01

    Full Text Available An organocatalytic protocol for the synthesis of dimethyl carbonate has been developed. Under the catalysis of 5 mol% N-heterocyclic carbenes, ethylene carbonate undergoes transesterification reaction with methanol under very mild reaction conditions, producing dimethyl carbonate with high efficiency. Furthermore, this N-heterocyclic carbene promoted transesterification can be scaled-up easily without lose of the conversion of dimethyl carbonate.

  12. Synthesis and antiacetylcholinesterase activity of new D-glyceraldehyde heterocyclic derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Scorzo, Cecilia M.; Fascio, Mirta L.; D' Accorso, Norma B. [Universidad de Buenos Aires, Buenos Aires (Argentina). Facultad de Ciencias Exactas y Naturales. Dept. de Quimica Organica; Cabrera, Margarita Gutierrez; Saavedra, Luis Astudillo [Universidad de Talca (Chile). Inst. de Quimica de Productos Naturales. Lab. de Sintesis Organica

    2010-07-01

    We report herein the convenient procedures for the syntheses of different heterocyclic compounds from 2,3-O-isopropylidene-D-glyceraldehyde using intramolecular cyclization, 1,3-dipolar cycloaddition or bimolecular coupling reactions. The products were characterized by {sup 1}H and {sup 13}C NMR spectroscopy and elemental analysis. The new heterocycles and their derivatives were evaluated as inhibitors of acetylcholinesterase enzyme. (author)

  13. The Lewis Acid-promoted Novel Cyclization Reactions Towards N-adn O-Containing Heterocycles

    Institute of Scientific and Technical Information of China (English)

    Shoko; Yamazaki

    2007-01-01

    1 Results Nitrogen and oxygen-containing heterocyclic systems are important structures in organic chemistry because of their presence in many biologically active compounds.In this work,a new zinc and indium-promoted conjugate addition-cyclization reaction to afford nitrogen and oxygen-containing five-membered heterocycles has been developed.A Lewis acid-catalyzed cyclization of an ethenetricarboxylate derivative with propargylamines or propargyl alcohols to give methylenepyrrolidines and methylenetetrah...

  14. Spherical core-shell magnetic particles constructed by main-chain palladium N-heterocyclic carbenes

    Science.gov (United States)

    Zhao, Huaixia; Li, Liuyi; Wang, Jinyun; Wang, Ruihu

    2015-02-01

    The encapsulation of the functional species on magnetic core is a facile approach for the synthesis of core-shell magnetic materials, and surface encapsulating matrices play crucial roles in regulating their properties and applications. In this study, two core-shell palladium N-heterocyclic carbene (NHC) particles (Fe3O4@PNP1 and Fe3O4@PNP2) were prepared by a one-pot reaction of semi-rigid tripodal imidazolium salts and palladium acetate in the presence of magnetite nanoparticles. The magnetite nanoparticles are encapsulated inside the main-chain palladium, which act as cores. The conjugated effects of triphenyltriazine and triphenylbenzene in the imidazolium salts have important influence on their physical properties and catalytic performances. Fe3O4@PNP2 shows better recyclability than Fe3O4@PNP1. Unexpectedly, Pd(ii) is well maintained after six consecutive catalytic runs in Fe3O4@PNP2, and Pd(0) and Pd(ii) coexist in Fe3O4@PNP1 under the same conditions; moreover, the morphologies of these spherical core-shell particles show no significant variation after six consecutive catalytic runs.The encapsulation of the functional species on magnetic core is a facile approach for the synthesis of core-shell magnetic materials, and surface encapsulating matrices play crucial roles in regulating their properties and applications. In this study, two core-shell palladium N-heterocyclic carbene (NHC) particles (Fe3O4@PNP1 and Fe3O4@PNP2) were prepared by a one-pot reaction of semi-rigid tripodal imidazolium salts and palladium acetate in the presence of magnetite nanoparticles. The magnetite nanoparticles are encapsulated inside the main-chain palladium, which act as cores. The conjugated effects of triphenyltriazine and triphenylbenzene in the imidazolium salts have important influence on their physical properties and catalytic performances. Fe3O4@PNP2 shows better recyclability than Fe3O4@PNP1. Unexpectedly, Pd(ii) is well maintained after six consecutive catalytic runs in

  15. Does a Non-Circular Chainring Improve Performance in the Bicycle Motocross Cycling Start Sprint?

    Science.gov (United States)

    Mateo-March, Manuel; Fernández-Peña, Eneko; Blasco-Lafarga, Cristina; Morente-Sánchez, Jaime; Zabala, Mikel

    2014-01-01

    Maximising power output during the initial acceleration phase of a bicycle motocross (BMX) race increases the chance to lead the group for the rest of the race. The purpose of this study was to investigate the effect of non-circular chainrings (Q-ring) on performance during the initial acceleration phase of a BMX race. Sixteen male cyclists (Spanish National BMX team) performed two counterbalanced and randomized initial sprints (3.95s), using Q- ring vs. circular chainring, on a BMX track. The sample was divided into two different groups according to their performance (Elite; n = 8 vs. Cadet; n = 8). Elite group covered a greater distance using Q-ring (+0.26 m, p = 0.02; D = 0.23), whilst the improvement for the Cadet (+0.04 m) was not significant (p = 0.87; D = -0.02). Also, there was no significant difference in power output for the Elite group, while the Cadet group revealed larger peak power with the circular chainring. Neither lactate level, nor heart rate showed significant differences due to the different chainring used. The non-circular chainring improved the initial acceleration capacity only in the Elite riders. Key Points This work provides novel results demonstrating very significant improvements in the sprint performance of BMX cycling discipline using a non-circular chainring system. This study seeks a practical application from scientific analysis All data are obtained in a real context of high competition using a sample comprised by the National Spanish Team. Some variables influencing performance as subjects’ physical fitness are discussed. Technical equipment approved by International Cycling Union is studied to check its potentially beneficial influence on performance. PMID:24570612

  16. Ring-strain-enabled reaction discovery: new heterocycles from bicyclo[1.1.0]butanes.

    Science.gov (United States)

    Walczak, Maciej A A; Krainz, Tanja; Wipf, Peter

    2015-04-21

    Mechanistically as well as synthetically, bicyclo[1.1.0]butanes represent one of the most fascinating classes of organic compounds. They offer a unique blend of compact size (four carbon atoms), high reactivity (strain energy of 66 kcal/mol), and mechanistic pathway diversity that can be harvested for the rapid assembly of complex scaffolds. The C(1)-C(3) bond combines the electronic features of both σ and π bonds with facile homolytic and heterolytic bond dissociation properties and thereby readily engages pericyclic, transition-metal-mediated, nucleophilic, and electrophilic pathways as well as radical acceptor and donor substrates. Despite this multifaceted reaction profile and recent advances in the preparation of bicylo[1.1.0]butanes, the current portfolio of synthetic applications is still limited compared with those of cyclopropanes and cyclobutanes. In this Account, we describe our work over the past decade on the exploration of substituent effects on the ring strain and the reactivity of bicyclo[1.1.0]butanes, particularly in the context of metal-mediated processes. We first describe Rh(I)-catalyzed cycloisomerization reactions of N-allyl amines to give pyrrolidine and azepine heterocycles. The regioselectivity of the C,C-bond insertion/ring-opening step in these reactions is controlled by the phosphine ligand. After metal carbene formation, an intramolecular cyclopropanation adds a second fused ring system. A proposed mechanism rationalizes why rhodium(I) complexes with monodentate ligands favor five-membered heterocycles, as opposed to Rh(I)-bidentate ligand catalysts, which rearrange N-allyl amines to seven-membered heterocycles. The scope of Rh(I)-catalyzed cycloisomerization reactions was extended to allyl ethers, which provide a mixture of five- and seven-membered cyclic ethers regardless of the nature of the phosphine additive and Rh(I) precatalyst. The chemical diversity of these cycloisomerization products was further expanded by a consecutive

  17. [Distribution and sources of oxygen and sulfur heterocyclic aromatic compounds in surface soil of Beijing, China].

    Science.gov (United States)

    He, Guang-Xiu; Zhang, Zhi-Huan; Peng, Xu-Yang; Zhu, Lei; Lu, Ling

    2011-11-01

    62 surface soil samples were collected from different environmental function zones in Beijing. Sulfur and oxygen heterocyclic aromatic compounds were detected by GC/MS. The objectives of this study were to identify the composition and distribution of these compounds, and discuss their sources. The results showed that the oxygen and sulfur heterocyclic aromatic compounds in the surface soils mainly contained dibenzofuran, methyl- and C2-dibenzofuran series, dibenzothiophene, methyl-, C2- and C3-dibenzothiophene series and benzonaphthothiophene series. The composition and distribution of the oxygen and sulfur heterocyclic aromatic compounds in the surface soil samples varied in the different environmental function zones, of which some factories and the urban area received oxygen and sulfur heterocyclic aromatic compounds most seriously. In Beijing, the degree of contamination by oxygen and sulfur heterocyclic aromatic compounds in the north surface soil was higher than that in the south. There were preferable linear correlations between the concentration of dibenzofuran series and fluorene series, as well as the concentration of dibenzothiophene series and dibenzofuran series. The oxygen and sulfur heterocyclic aromatic compounds in the surface soil were mainly derived from combustion products of oil and coal and direct input of mineral oil, etc. There were some variations in pollution sources of different environmental function zones.

  18. 16 CFR Figure 1 to Part 1512 - Bicycle Front Fork Cantilever Bending Test Rig

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Bicycle Front Fork Cantilever Bending Test Rig 1 Figure 1 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS... Fork Cantilever Bending Test Rig EC03OC91.070...

  19. The Effects of Prompting and Reinforcement on Safe Behavior of Bicycle and Motorcycle Riders

    Science.gov (United States)

    Okinaka, Takeru; Shimazaki, Tsuneo

    2011-01-01

    A reversal design was used to evaluate the effects of vocal and written prompts as well as reinforcement on safe behavior (dismounting and walking bicycles or motorcycles on a sidewalk) on a university campus. Results indicated that an intervention that consisted of vocal and written prompts and reinforcement delivered by security guards was…

  20. A Study of Bicycle and Passenger Car Collisions Based on Insurance Claims Data

    Science.gov (United States)

    Isaksson-Hellman, Irene

    2012-01-01

    In Sweden, bicycle crashes are under-reported in the official statistics that are based on police reports. Statistics from hospital reports show that cyclists constitute the highest percentage of severely injured road users compared to other road user groups. However, hospital reports lack detailed information about the crash. To get a more comprehensive view, additional data are needed to accurately reflect the casualty situation for cyclists. An analysis based on 438 cases of bicycle and passenger car collisions is presented, using data collected from insurance claims. The most frequent crash situations are described with factors as to where and when collisions occur, age and gender of the involved cyclists and drivers. Information on environmental circumstances such as road status, weather- and light conditions, speedlimits and traffic environment is also included. Based on the various crash events, a total of 32 different scenarios have been categorized, and it was found that more than 75% were different kinds of intersection related situations. From the data, it was concluded that factors such as estimated impact speed and age significantly influence injury severity. The insurance claims data complement the official statistics and provide a more comprehensive view of bicycle and passenger car collisions by considering all levels of crash and injury severity. The detailed descriptions of the crash situations also provide an opportunity to find countermeasures to prevent or mitigate collisions. The results provide a useful basis, and facilitates the work of reducing the number of bicycle and passenger car collisions with serious consequences. PMID:23169111

  1. Macroscopic modeling of pedestrian and bicycle crashes: A cross-comparison of estimation methods.

    Science.gov (United States)

    Amoh-Gyimah, Richard; Saberi, Meead; Sarvi, Majid

    2016-08-01

    The paper presents a cross-comparison of different estimation methods to model pedestrian and bicycle crashes. The study contributes to macro level safety studies by providing further methodological and empirical evidence on the various factors that influence the frequency of pedestrian and bicycle crashes at the planning level. Random parameter negative binomial (RPNB) models are estimated to explore the effects of various planning factors associated with total, serious injury and minor injury crashes while accounting for unobserved heterogeneity. Results of the RPNB models were compared with the results of a non-spatial negative binomial (NB) model and a Poisson-Gamma-CAR model. Key findings are, (1) the RPNB model performed best with the lowest mean absolute deviation, mean squared predicted error and Akaiki information criterion measures and (2) signs of estimated parameters are consistent if these variables are significant in models with the same response variables. We found that vehicle kilometers traveled (VKT), population, percentage of commuters cycling or walking to work, and percentage of households without motor vehicles have a significant and positive correlation with the number of pedestrian and bicycle crashes. Mixed land use is also found to have a positive association with the number of pedestrian and bicycle crashes. Results have planning and policy implications aimed at encouraging the use of sustainable modes of transportation while ensuring the safety of pedestrians and cyclist. PMID:27209153

  2. Tertiary Student Attitudes to Bicycle Commuting in a Regional Australian University

    Science.gov (United States)

    Whannell, Patricia; Whannell, Robert; White, Richard

    2012-01-01

    Purpose: The purpose of this paper is to provide executive management at a regional university with empirical data to justify, or otherwise, a substantial outlay of funds to support bicycle commuting as a viable strategy for the reduction of traffic congestion. Design/methodology/approach: A custom designed questionnaire was completed by 270…

  3. [Changes in ECG indicators during bicycle ergometry in patients having suffered myocardial infarction].

    Science.gov (United States)

    Kheifets, Z N

    1984-01-01

    Altogether 218 patients with a history of myocardial infarction were subjected to bicycle ergometry. The ECG recorded at the height of the exercise showed a significant increase in the heart rate and in the amplitudes of P and R waves. The diastole and electric systole shortened. As the load was raised, the rate of A-B conduction was relatively decelerated.

  4. Modeling Mixed Bicycle Traffic Flow: A Comparative Study on the Cellular Automata Approach

    Directory of Open Access Journals (Sweden)

    Dan Zhou

    2015-01-01

    Full Text Available Simulation, as a powerful tool for evaluating transportation systems, has been widely used in transportation planning, management, and operations. Most of the simulation models are focused on motorized vehicles, and the modeling of nonmotorized vehicles is ignored. The cellular automata (CA model is a very important simulation approach and is widely used for motorized vehicle traffic. The Nagel-Schreckenberg (NS CA model and the multivalue CA (M-CA model are two categories of CA model that have been used in previous studies on bicycle traffic flow. This paper improves on these two CA models and also compares their characteristics. It introduces a two-lane NS CA model and M-CA model for both regular bicycles (RBs and electric bicycles (EBs. In the research for this paper, many cases, featuring different values for the slowing down probability, lane-changing probability, and proportion of EBs, were simulated, while the fundamental diagrams and capacities of the proposed models were analyzed and compared between the two models. Field data were collected for the evaluation of the two models. The results show that the M-CA model exhibits more stable performance than the two-lane NS model and provides results that are closer to real bicycle traffic.

  5. Design of an aluminium bicycle path integrated in a steel bridge

    NARCIS (Netherlands)

    Maljaars, J.; Soetens, F.; Burggraaf, H.G.

    2007-01-01

    This paper describes the design of the aluminium structure of a bicycle path which is mounted on an existing steel brige. The benefits of aluminium, being low self weight, freedom in design obtained by extrusion and good corrosion resistance were maximal utilized. One of the main drawbacks of alumin

  6. Sensor design for outdoor racing bicycle field testing for human vibration comfort evaluation

    International Nuclear Information System (INIS)

    This paper is concerned with the vibrational comfort evaluation of the cyclist when cycling a rough surface. Outdoor comfort tests have so far only been done through instrumenting the bicycle with accelerometers. This work instruments a racing bicycle with custom-made contact force sensors and velocity sensors to acquire human comfort through the absorbed power method. Comfort evaluation is assessed at the hand–arm and seat interface of the cyclist with the bicycle. By means of careful finite-element analysis for designing the force gauges at the handlebar and the seat combined with precise calibration of both force and velocity sensors, all sensors have proven to work properly. Initial field tests are focused on the proper functioning of the designed sensors and their suitability for vibration comfort measurements. Tests on a cobblestone road reveal that the outcome of the absorbed power values is within the same range as those from laboratory tests found in the literature. This sensor design approach for outdoor testing with racing bicycles may give a new interpretation on evaluating the cyclist's comfort since the vibrational load is not only quantified in terms of acceleration but also in terms of force and velocity at the bicycle–cyclist contact points. (paper)

  7. Road safety and bicycle usage impacts of unbundling vehicular and cycle traffic in Dutch urban networks.

    NARCIS (Netherlands)

    Schepers, P. Heinen, E. Methorst, R. & Wegman, F.

    2015-01-01

    Bicycle-motor vehicle crashes are concentrated along distributor roads where cyclists are exposed to greater volumes of high-speed motorists than they would experience on access roads. This study examined the road safety impact of network-level separation of vehicular and cycle traffic in Dutch urba

  8. Road safety and bicycle usage impacts of unbundling vehicular and cycle traffic in Dutch urban networks

    NARCIS (Netherlands)

    Schepers, P.; Heinen, E.; Methorst, R.; Wegman, F.C.M.

    2013-01-01

    Bicycle-motor vehicle crashes are concentrated along distributor roads where cyclists are exposed to greater volumes of high-speed motorists than they would experience on access roads. This study examined the road safety impact of network-level separation of vehicular and cycle traffic in Dutch urba

  9. Balance and control of a rear-wheel steered speed-record recumbent bicycle

    NARCIS (Netherlands)

    Schwab, A.L.; Kooijman, J.D.G.

    2014-01-01

    The goal of the Human Power Team from the TU Delft and the Free University of Amsterdam is to break the world speed record in unpaced cycling (Sam Whittingham, 133.28 km/h). The design of such a faired recumbent bicycle is a challenge. The Delft design, called VeloX (Human Power Team (2013)), is a f

  10. Building the fastest bicycle in the world; a year with the Human Power Team Delft & Amsterdam

    NARCIS (Netherlands)

    Schuurman, M.; Roks, G.

    2014-01-01

    “Third time lucky” is the saying, but for the third Human Power Team it almost turned out as a year for nothing. The team has been attempting to set the world record for the fastest bicycle powered only by human muscles for two years already. This endeavor to let a Dutchman be the fastest human on e

  11. Comparison of dipyridamole-handgrip test and bicycle exercise test for thallium tomographic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Huikuri, H.V.; Korhonen, U.R.; Airaksinen, J.; Ikaeheimo, M.J.H.; Heikkilae, J.T.; Takkunen, J.T.

    1988-02-01

    Seventy-three patients with angina pectoris and 20 with atypical chest pain, who underwent coronary angiography, were examined by single-photon emission computed thallium tomography (TI-SPECT) using a combined dipyridamole-handgrip stress test. Perfusion defects were detected in 78 of 81 patients with angiographically significant coronary artery disease (CAD) (sensitivity 96%). In 9 of 12 patients without CAD, the thallium images were normal (specificity 75%). Thirty-five patients with CAD were reexamined by TI-SPECT using a dynamic bicycle exercise stress test. The sensitivity of the dipyridamole-handgrip test did not differ from the bicycle exercise test in diagnosing the CAD (97% vs 94%). Multiple thallium defects were seen in 19 of 22 (86%) patients with multivessel CAD by the dipyridamole-handgrip test but only in 14 of 22 (64%) by the bicycle exercise test. Noncardiac side-effects occurred in 17 of 93 (18%) patients after dipyridamole infusion. Cardiac symptoms were less common during the dipyridamole-handgrip test than during the bicycle exercise (15% vs 76%, p less than 0.01). These data suggest that the dipyridamole-handgrip test is a useful alternative stress method for thallium perfusion imaging, particularly in detecting multivessel CAD.

  12. 77 FR 60050 - Special Regulations; Areas of the National Park System, Saguaro National Park, Bicycling

    Science.gov (United States)

    2012-10-02

    ... and adopted by NPS leadership after an adequate analysis of the benefits, impacts, and economic cost... Hope Camp Trail as a bicycle route within Saguaro National Park (77 FR 12761). The proposed rule was... solitude and wilderness-like aesthetics that are long-standing attributes in this area and the primary...

  13. Sandia bicycle commuters group -- pollution prevention at Sandia National Laboratories, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Wrons, R.

    1998-06-01

    The Sandia Bicycle Commuters Group (SBCG) formed three years ago for the purpose of addressing issues that impact the bicycle commuting option. The meeting that launched the SBCG was scheduled in conjunction with National Bike-to-Work day in May 1995. Results from a survey handed out at the meeting solidly confirmed the issues and that an advocacy group was needed. The purpose statement for the Group headlines its web site and brochure: ``Existing to assist and educate the SNL workforce bicyclist on issues regarding Kirtland Air Force Base (KAFB) access, safety and bicycle-supporting facilities, in order to promote bicycling as an effective and enjoyable means of commuting.`` The SNL Pollution Prevention (P2) Team`s challenge to the SNL workforce is to ``prevent pollution, conserve natural resources, and save money``. In the first winter of its existence, the SBCG sponsored a winter commute contest in conjunction with the City`s Clean Air Campaign (CAC). The intent of the CAC is to promote alternative (to the single-occupant vehicle) commuting during the Winter Pollution Advisory Period (October 1--February 28), when the City runs the greatest risk of exceeding federal pollution limits.

  14. THE EFFECTS OF SURFACE-INDUCED LOADS ON FOREARM MUSCLE ACTIVITY DURING STEERING A BICYCLE

    Directory of Open Access Journals (Sweden)

    Pinar Arpinar-Avsar

    2013-09-01

    Full Text Available On the bicycle, the human upper extremity has two essential functions in steering the bicycle and in supporting the body. Through the handlebar, surface- induced loads are transmitted to the hand and arm of the bicycle rider under vibration exposure conditions. Thus, the purpose of the study was to investigate the effect of vibration exposure on forearm muscle activity for different road surfaces (i.e. smooth road, concrete stone pavement, rough road and for different bicycles. Ten subjects participated in experiments and two types of bicycles, i.e. Road Bike (RB and Mountain Bike (MTB are compared. The acceleration magnitudes were dominant along x and z-axes. The r.m.s acceleration values in the z direction at the stem of MTB were at most 2.56, 7.04 and 10.76 m·s-2 when pedaling respectively on asphalt road, concrete pavement and rough road. In the case of RB the corresponding values were respectively 4.43, 11.75 and 27.31 m·s-2. The cumulative normalized muscular activity levels during MTB trials on different surfaces had the same tendency as with acceleration amplitudes and have ranked in the same order from lowest to highest value. Although road bike measurements have resulted in a similar trend of increment, the values computed for rough road trials were higher than those in MTB trials. During rough road measurements on MTB, rmsEMG of extensor muscles reached a value corresponding to approximately 50% of MVC (Maximum Voluntary Contraction. During RB trials performed on rough road conditions, rmsEMG (%MVC values for the forearm flexor muscles reached 45.8% of their maximal. The level of muscular activity of forearm muscles in controlling handlebar movements has been observed to be enhanced by the increase in the level of vibration exposed on the bicycle. Since repeated forceful gripping and pushing forces to a handle of a vibratory tool can create a risk of developing circulatory, neurological, or musculoskeletal disorder, a bicycle rider

  15. Impact Evaluation of a Public Bicycle Share Program on Cycling: A Case Example of BIXI in Montreal, Quebec

    Science.gov (United States)

    Gauvin, Lise; Kestens, Yan; Fournier, Michel; Morency, Patrick; Drouin, Louis

    2013-01-01

    Objectives. We examined associations between residential exposure to BIXI (BIcycle-taXI)—a public bicycle share program implemented in Montreal, Quebec, in 2009, which increases accessibility to cycling by making available 5050 bicycles at 405 bicycle docking stations—and likelihood of cycling (BIXI and non-BIXI) in Montreal over the first 2 years of implementation. Methods. Three population-based samples of adults participated in telephone surveys. Data collection occurred at the launch of the program (spring 2009), and at the end of the first (fall 2009) and second (fall 2010) seasons of implementation. Difference in differences models assessed whether greater cycling was observed for those exposed to BIXI compared with those not exposed at each time point. Results. We observed a greater likelihood of cycling for those exposed to the public bicycle share program after the second season of implementation (odds ratio = 2.86; 95% confidence interval = 1.85, 4.42) after we controlled for weather, built environment, and individual variables. Conclusions. The implementation of a public bicycle share program can lead to greater likelihood of cycling among persons living in areas where bicycles are made available. PMID:23327280

  16. Determining the Optimal Layout Design for Public Bicycle System within the Attractive Scope of a Metro Station

    Directory of Open Access Journals (Sweden)

    Jingxu Chen

    2015-01-01

    Full Text Available Public bicycle acts as a seamless feeder mode in combination with the citywide public transit, as well as a competitor for the inner-city short trips. The primary objective of this study is to address the layout planning of public bicycle system within the attracted scope of a metro station. Based on the land use function, population, and bicycle mode share, bicycle rental stations are divided into three types, namely, the metro station, district station, and resident station, and later the quantity of bicycle facilities in each rental station is estimated. Then, the service stations are selected from these bicycle rental stations to provide the service of periodical bicycle redistribution. An improved immune algorithm is proposed to determine the number and locations of service stations and the optimal route options for the implement of redistributing strategy. Finally, a case study of Nanjing Tianyin Road metro station is conducted to illustrate the proposed model and clarify some of its implementation details.

  17. The oxime portmanteau motif: released heteroradicals undergo incisive EPR interrogation and deliver diverse heterocycles.

    Science.gov (United States)

    Walton, John C

    2014-04-15

    systems. Microwave irradiations with 2-(aminoaryl)alkanone O-phenyl oximes enabled either dihydroquinazolines or quinazolines to be obtained in very good yields. The fine quality of the EPR spectra, acquired during photolyses of all the O-carbonyl oxime types, marked this as an important complement to existing ways of obtaining such spectra in solution. Quantifications enabled SARs to be obtained for key reaction types of N- and O-centered radicals, thus putting mechanistic chemistry in this area on a much firmer footing. Surprises included the inverse gem-dimethyl effect in 5-exo-cyclizations of iminyls and the interplay of spiro- with ortho-cyclization onto aromatics. Insights into unusual 4-exo-cyclizations of carbamoyl radicals showed the process to be more viable than pent-4-enyl 4-exo-ring closure. Another surprise was the magnitude of the difference in CO2 loss rate from alkoxycarbonyloxyl radicals as compared with acyloxyl radicals. Their rapid 5-exo-cyclization was charted, as was their preferred spiro-cyclization onto aromatics. The first evidence that N-monosubstituted carbamoyloxyls had finite lifetimes was also forthcoming. It is evident that oxime derivatives have excellent credentials as reagents for radical generation and that there is ample room to extend their applications to additional radical types and for further heterocycle syntheses. There is also clear scope for the development of preparative procedures based around the alkoxyl and aminyl radicals that emerge downstream from oxime carbonate and oxime carbamate dissociations. PMID:24654991

  18. Enantioselective Recognition of Calix [4] arene Derivative Bearing Bicyclic Guanidinium for D/L Amino Acid Zwitterions

    Institute of Scientific and Technical Information of China (English)

    刘芳; 陆国元; 何卫江; 王震生; 朱龙根

    2001-01-01

    The p-tetra-tert-butyl calix[4]arene derivatives ( 3 and 4 )with(S,S) chiral bicyclic guanidinium, as the receptors of amino acid zwitterions, have been synthesized via a O-alkylation reaction of p-tetra-tert-rutyi calix [4] arene with chloromethly chiral bicyclic guanidinium 2 in the presence of anhydrous K2CO3 in acetonitrile.The results obtained from liquid-liquid competitive extraction experiments indicate that the two receptors may selectively recognize L-aromatic amino acids, and that the enantioselective recognizability of the receptor 4 with two chiral bicyclic guanidinium units reachs up to about 90% for L-Phe.

  19. Does the Effect of Micro-Environmental Factors on a Street's Appeal for Adults' Bicycle Transport Vary across Different Macro-Environments? An Experimental Study.

    Directory of Open Access Journals (Sweden)

    Lieze Mertens

    Full Text Available Characteristics of the physical environment can be classified into two broad categories: macro- ("raw" urban planning features influenced on a regional level and micro- (features specifically within a streetscape influenced on a neighborhood level environmental factors. In urban planning applications, it is more feasible to modify conditions at the neighborhood level than at the regional level. Yet for the promotion of bicycle transport we need to know whether relationships between micro-environmental factors and bicycle transport depend on different types of macro-environments. This study aimed to identify whether the effect of three micro-environmental factors (i.e., evenness of the cycle path surface, speed limits and type of separation between cycle path and motorized traffic on the street's appeal for adults' bicycle transport varied across three different macro-environments (i.e., low, medium and high residential density street.In total, 389 middle-aged adults completed a web-based questionnaire consisting of socio-demographic characteristics and a series of choice tasks with manipulated photographs, depicting two possible routes to cycle along. Conjoint analysis was used to analyze the data.Although the magnitude of the overall effects differed, in each macro-environment (i.e., low, medium and high residential density, middle-aged adults preferred a speed limit of 30 km/h, an even cycle path surface and a hedge as separation between motorized traffic and the cycle path compared to a speed limit of 50 or 70 km/h, a slightly uneven or uneven cycle path surface and a curb as separation or no separation between motorized traffic and the cycle path.Our results suggest that irrespective of the macro-environment, the same micro-environmental factors are preferred in middle-aged adults concerning the street's appeal for bicycle transport. The controlled environment simulations in the experimental choice task have the potential to inform real life

  20. Effect of thermal treatment on meat proteins with special reference to heterocyclic aromatic amines (HAAs).

    Science.gov (United States)

    Shabbir, Muhammad Asim; Raza, Ali; Anjum, Faqir Muhammad; Khan, Moazzam Rafiq; Suleria, Hafiz Ansar Rasul

    2015-01-01

    Meat is one of the most imperative protein sources available with respect to its production and consumption. It is the richest source of some valuable nutrients like proteins, essential amino acids, polyunsaturated fatty acids, vitamins, and minerals like iron, zinc, and selenium. Thermal treatment produces conformational changes in protein structure as well as flavor, texture, and appearance, and chemical properties of the ingredients are also changed. Heterocyclic aromatic amines (HAAs), potent mutagens/carcinogens, are formed during the cooking of meat at high temperature. The review paper highlights the effects of various cooking methods, i.e., pan-frying, deep-frying, charcoal grilling, and roasting, on the formation of HAAs. The levels of HAAs produced in cooked meats vary depending upon the cooking method, time of cooking, and the type of meat being cooked. Metabolic behavior of HAAs is very unique, they interfere in the activity of many enzymes, modify the metabolic pathways, and lead to the adduct formation of DNA. The application of black pepper and several other spices during processing may reduce the formation of these (HAAs) mutagenic compounds. PMID:24915407

  1. Adsorption on Mesoporous Metal-Organic Frameworks in Solution: Aromatic and Heterocyclic Compounds.

    Science.gov (United States)

    Samokhvalov, Alexander

    2015-11-16

    Adsorption and desorption play major roles in separations, purification of water, waste streams, liquid fuels, catalysis, biomedicine and chromatography. Mesoporous metal-organic frameworks (MOFs) with pore sizes 2-50 nm are particularly suitable for adsorption of organic compounds in solution. Tens of thousands of aromatic and heterocyclic compounds are major components of liquid fuels, feedstock for industrial synthesis, solvents, dyestuffs, agricultural chemicals, medicinal drugs, food additives, and so forth. This Review provides a systematization and analysis of studies on adsorption/desorption on mesoporous MOFs in solution and their underlying chemical mechanisms. The (in)stability of mesoporous MOFs in water is critically discussed. Adsorption capacity and selectivity are covered for organic dyes, medicinal drugs, major components of liquid fuels, and miscellaneous industrial chemicals. Ionic interactions, Brønsted acid-base interactions, hydrogen bonding, coordination bonding, π-π interactions, and non-specific interactions are covered amongst adsorption mechanisms. The effects of post-synthetic modifications of mesoporous MOFs on their stability, adsorption capacity, selectivity, and mechanisms of adsorption and desorption are analyzed. To encourage research in this quickly growing field, we identify "niches" for which no application-oriented and/or mechanistic studies were reported. Perspectives and limitations of a wide use of mesoporous MOFs as industrial sorbents are discussed.

  2. Optoelectronic studies on heterocyclic bases of deoxyribonucleic acid for DNA photonics

    Energy Technology Data Exchange (ETDEWEB)

    El-Diasty, Fouad, E-mail: fdiasty@yahoo.com; Abdel-Wahab, Fathy

    2015-10-01

    The optoelectronics study of large molecules, particularly π-stacking molecules, such as DNA is really an extremely difficult task. We perform first electronic structure calculations on the heterocyclic bases of 2′-deoxyribonucleic acid based on Lorentz–Fresnel dispersion theory. In the UV–VIS range of spectrum, many of the optoelectronic parameters for DNA four bases namely adenine, guanine, cytosine and thymine are calculated and discussed. The results demonstrate that adenine has the highest hyperpolarizability, whereas thymine has the lowest hyperpolarizability. Cytosine has the lower average oscillator energy and the higher lattice energy. Thymine infers the most stable nucleic base with the lower phonon energy. Thymine also has the highest average oscillator energy and the lower lattice energy. Moreover, the four nucleic acid bases have large band gap energies less than 5 eV with a semiconducting behavior. Guanine shows the smallest band gap and the highest Fermi level energy, whereas adenine elucidates the highest band gap energy. - Highlights: • Optical constants of the four DNA bases are determined. • Band gap energy, Fermi level, average oscillator energy, oscillator strength and lattice energy are calculated and analyzed. • Results provide some useful references for the potential application of the DNA bases in optoelectronic devices.

  3. Bicycle transport as an object of ecological marketing and innovations in urban transportations

    Directory of Open Access Journals (Sweden)

    O.S. Teletov

    2016-09-01

    Full Text Available The aim of the article. In the modern world society is faced with problems of growing population, increasing environmental problems, lack of minerals and social-economic globalization when necessity of both individual and humanity survival is becoming extremely important. By next few years 80% of the world’s population will live in the cities. This is the main reason which force us to think about the more effective usage of urban space and transport people in cities. Nowadays ecological pollution and increased costs on transport service highlight the importance of seeking alternative types of transport. The youth of many European countries prefer bikes as main transport. Usage of bicycles in Europe is constantly growing due to European and local urban and mobility policies. Therefore, we may consider an opportunity to promote bicycle transport in Ukraine, that requires complex investigation of this question. The purpose of the article is to define features and the ways of bicycle transport implementation in Ukrainian cities as a priority for youth; it includes the best world practices of bicycle transport implementation into urban space and searching for possible ways to apply the European experience in Ukraine. The results of the analysis. As a part of our research we considered investigating international experience of cycling in Europe as an alternative to the public transport and as an example of ecological marketing. The best methods of usage cycling in the urban space were described and analysed. Moreover, we identified the main problems (and the potential solutions with implementation of cycling infrastructure in urban space based on international and national experience (special signs, traffic lights etc.. In the article different opportunities for realization in city Sumy were proposed. Our focus was on atomized network of bike rental services and we confirmed the effectiveness of such program in this city. The bicycle infrastructure

  4. Microwave-Assisted Syntheses of Bioactive Seven-Membered, Macro-Sized Heterocycles and Their Fused Derivatives.

    Science.gov (United States)

    Driowya, Mohsine; Saber, Aziza; Marzag, Hamid; Demange, Luc; Bougrin, Khalid; Benhida, Rachid

    2016-01-01

    This review describes the recent advances in the microwave-assisted synthesis of 7-membered and larger heterocyclic compounds. Several types of reaction for the cyclization step are discussed: Ring Closing Metathesis (RCM), Heck and Sonogashira reactions, Suzuki-Miyaura cross-coupling, dipolar cycloadditions, multi-component reactions (Ugi, Passerini), etc. Green syntheses and solvent-free procedures have been introduced whenever possible. The syntheses discussed herein have been selected to illustrate the huge potential of microwave in the synthesis of highly functionalized molecules with potential therapeutic applications, in high yields, enhanced reaction rates and increased chemoselectivity, compared to conventional methods. More than 100 references from the recent literature are listed in this review. PMID:27517892

  5. Sulfur-Functionalized N-Heterocyclic Carbene Complexes of Pd(II: Syntheses, Structures and Catalytic Activities

    Directory of Open Access Journals (Sweden)

    Dan Yuan

    2012-03-01

    Full Text Available N-heterocyclic carbenes (NHCs can be easily modified by introducing functional groups at the nitrogen atoms, which leads to versatile coordination chemistry as well as diverse catalytic applications of the resulting complexes. This article summarizes our contributions to the field of NHCs bearing different types of sulfur functions, i.e., thioether, sulfoxide, thiophene, and thiolato. The experimental evidence for the truly hemilabile coordination behavior of a Pd(II thioether-NHC complex has been reported as well. In addition, complexes bearing rigid CSC-pincer ligands have been synthesized and the reasons for pincer versus pseudo-pincer formation investigated. Incorporation of the electron-rich thiolato function resulted in the isolation of structurally diverse complexes. The catalytic activities of selected complexes have been tested in Suzuki-Miyaura, Mizoroki-Heck and hydroamination reactions.

  6. Aprotic Heterocyclic Anion Triazolide Ionic Liquids - A New Class of Ionic Liquid Anion Accessed by the Huisgen Cycloaddition Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Robert L; Damodaran, Krishnan; Luebke, David; Nulwala, Hunaid

    2013-06-01

    The triazole core is a highly versatile heterocyclic ring which can be accessed easily with the Cu(I)-catalyzed Huisgen cycloaddition reaction. Herein we present the preparation of ionic liquids that incorporate a 1,2,3-triazolide anion. These ionic liquids were prepared by a facile procedure utilizing a base-labile pivaloylmethyl group at the 1-position, which can act as precursors to 1H- 4-substituted 1,2,3-triazole. These triazoles were then subsequently converted into ionic liquids after deprotonation using an appropriate ionic liquid cation hydroxide. The densities and thermal decompositions of these ionic liquids were measured. These novel ionic liquids have potential applications in gas separations and in metal-free catalysis.

  7. Microwave-Assisted Syntheses of Bioactive Seven-Membered, Macro-Sized Heterocycles and Their Fused Derivatives

    Directory of Open Access Journals (Sweden)

    Mohsine Driowya

    2016-08-01

    Full Text Available This review describes the recent advances in the microwave-assisted synthesis of 7-membered and larger heterocyclic compounds. Several types of reaction for the cyclization step are discussed: Ring Closing Metathesis (RCM, Heck and Sonogashira reactions, Suzuki-Miyaura cross-coupling, dipolar cycloadditions, multi-component reactions (Ugi, Passerini, etc. Green syntheses and solvent-free procedures have been introduced whenever possible. The syntheses discussed herein have been selected to illustrate the huge potential of microwave in the synthesis of highly functionalized molecules with potential therapeutic applications, in high yields, enhanced reaction rates and increased chemoselectivity, compared to conventional methods. More than 100 references from the recent literature are listed in this review.

  8. Two-dimensional character of internal rotation of furfural and other five-member heterocyclic aromatic aldehydes

    Science.gov (United States)

    Bataev, Vadim A.; Pupyshev, Vladimir I.; Godunov, Igor A.

    2016-05-01

    The features of nuclear motion corresponding to the rotation of the formyl group (CHO) are studied for the molecules of furfural and some other five-member heterocyclic aromatic aldehydes by the use of MP2/6-311G** quantum chemical approximation. It is demonstrated that the traditional one-dimensional models of internal rotation for the molecules studied have only limited applicability. The reason is the strong kinematic interaction of the rotation of the CHO group and out-of-plane CHO deformation that is realized for the molecules under consideration. The computational procedure based on the two-dimensional approximation is considered for low lying vibrational states as more adequate to the problem.

  9. Componentes voláteis do café torrado. Parte I: compostos heterocíclicos Volatile components in roasted coffee. Part I: heterocyclic compounds

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Bastos De Maria

    1999-04-01

    Full Text Available A review of heterocyclic compounds in roasted coffee is presented. The contents, precursors and sensorial properties of furans, pyrroles, oxazoles, thiazoles, thiophenes, pyrazines and pyridines are discussed. The impact heterocyclic compounds of coffee aroma are described.

  10. Ruthenium olefin metathesis catalysts featuring unsymmetrical N-heterocyclic carbenes.

    Science.gov (United States)

    Paradiso, Veronica; Bertolasi, Valerio; Costabile, Chiara; Grisi, Fabia

    2016-01-14

    New ruthenium Grubbs' and Hoveyda-Grubbs' second generation catalysts bearing N-alkyl/N-isopropylphenyl N-heterocyclic carbene (NHC) ligands with syn or anti backbone configuration were obtained and compared in model olefin metathesis reactions. Different catalytic efficiencies were observed depending on the size of the N-alkyl group (methyl or cyclohexyl) and on the backbone configuration. The presence of an N-cyclohexyl substituent determined the most significant reactivity differences between catalysts with syn or anti phenyl groups on the backbone. In particular, anti catalysts proved highly efficient, especially in the ring-closing metathesis (RCM) of encumbered diolefins, while syn catalysts showed low efficiency in the RCM of less hindered diolefins. This peculiar behavior, rationalized through DFT studies, was found to be related to the high propensity of these catalysts to give nonproductive metathesis events. Enantiopure anti catalysts were also tested in asymmetric metathesis reactions, where moderate enantioselectivities were observed. The steric and electronic properties of unsymmetrical NHCs with the N-cyclohexyl group were then evaluated using the corresponding rhodium complexes. While steric factors proved unimportant for both syn and anti NHCs, a major electron-donating character was found for the unsymmetrical NHC with anti phenyl substituents on the backbone. PMID:26608162

  11. Ruthenium olefin metathesis catalysts featuring unsymmetrical N-heterocyclic carbenes.

    Science.gov (United States)

    Paradiso, Veronica; Bertolasi, Valerio; Costabile, Chiara; Grisi, Fabia

    2016-01-14

    New ruthenium Grubbs' and Hoveyda-Grubbs' second generation catalysts bearing N-alkyl/N-isopropylphenyl N-heterocyclic carbene (NHC) ligands with syn or anti backbone configuration were obtained and compared in model olefin metathesis reactions. Different catalytic efficiencies were observed depending on the size of the N-alkyl group (methyl or cyclohexyl) and on the backbone configuration. The presence of an N-cyclohexyl substituent determined the most significant reactivity differences between catalysts with syn or anti phenyl groups on the backbone. In particular, anti catalysts proved highly efficient, especially in the ring-closing metathesis (RCM) of encumbered diolefins, while syn catalysts showed low efficiency in the RCM of less hindered diolefins. This peculiar behavior, rationalized through DFT studies, was found to be related to the high propensity of these catalysts to give nonproductive metathesis events. Enantiopure anti catalysts were also tested in asymmetric metathesis reactions, where moderate enantioselectivities were observed. The steric and electronic properties of unsymmetrical NHCs with the N-cyclohexyl group were then evaluated using the corresponding rhodium complexes. While steric factors proved unimportant for both syn and anti NHCs, a major electron-donating character was found for the unsymmetrical NHC with anti phenyl substituents on the backbone.

  12. Homobimetallic Ruthenium-N-Heterocyclic Carbene Complexes For Olefin Metathesis

    Science.gov (United States)

    Sauvage, Xavier; Demonceau, Albert; Delaude, Lionel

    In this chapter, the synthesis and catalytic activity towards olefin metathesis of homobimetallic ruthenium (Ru)-alkylidene, -cyclodiene or -arene complexes bearing phosphine or N-heterocyclic carbene (NHC) ligands are reviewed. Emphasis is placed on the last category of bimetallic compounds. Three representatives of this new type of molecular scaffold were investigated. Thus, [(p-cymene)Ru(m-Cl)3RuCl (h2-C2H4)(L)] complexes with L = PCy3 (15a), IMes (16a), or IMesCl2 (16b) were prepared. They served as catalyst precursors for cross-metathesis (CM) of various styrene derivatives. These experiments revealed the outstanding aptitude of complex 16a (and to a lesser extent of 16b) to catalyze olefin metathesis reactions. Contrary to monometallic Ru-arene complexes of the [RuCl2(p-cymene)(L)] type, the new homobimetallic species did not require the addition of a diazo compound nor visible light illumination to initiate the ring-opening metathesis of norbornene or cyclooctene. When diethyl 2,2-diallylmalonate and N,N-diallyltosylamide were exposed to 16a,b, a mixture of cycloisomerization and ring-closing metathesis (RCM) products was obtained in a nonselective way. Addition of phenylacetylene enhanced the metathetical activity while completely repressing the cycloisomerization process.

  13. Synthesis and cytotoxic potential of heterocyclic cyclohexanone analogues of curcumin.

    Science.gov (United States)

    Yadav, Babasaheb; Taurin, Sebastien; Rosengren, Rhonda J; Schumacher, Marc; Diederich, Marc; Somers-Edgar, Tiffany J; Larsen, Lesley

    2010-09-15

    A series of 18 heterocyclic cyclohexanone analogues of curcumin have been synthesised and screened for their activity in both adherent and non-adherent cancer cell models. Cytotoxicity towards MBA-MB-231 breast cancer cells, as well as ability to inhibit NF-kappaB transactivation in non-adherent K562 leukemia cells were investigated. Three of these analogues 3,5-bis(pyridine-4-yl)-1-methylpiperidin-4-one B1, 3,5-bis(3,4,5-trimethoxybenzylidene)-1-methylpiperidin-4-one B10, and 8-methyl-2,4-bis((pyridine-4-yl)methylene)-8-aza-bicyclo[3.2.1]octan-3-one C1 showed potent cytotoxicity towards MBA-MB-231, MDA-MB-468, and SkBr3 cell lines with EC50 values below 1 microM and inhibition of NF-kappaB activation below 7.5 microM. The lead drug candidate, B10, was also able to cause 43% of MDA-MB-231 cells to undergo apoptosis after 18 h. This level of activity warrants further investigation for the treatment of ER-negative breast cancer and/or chronic myelogenous leukemia as prototypical cellular models for solid and liquid tumors.

  14. Frustrated N-heterocyclic carbene-silylium ion Lewis pairs.

    Science.gov (United States)

    Silva Valverde, Miguel F; Theuergarten, Eileen; Bannenberg, Thomas; Freytag, Matthias; Jones, Peter G; Tamm, Matthias

    2015-05-28

    The reaction of the N-heterocyclic carbene 1,3-di-tert-butyl-4,5-dimethylimidazolin-2-ylidene () with trimethylsilyl iodide, triflate and triflimidate [Me3SiX, X = I, CF3SO3 (OTf), (CF3SO2)2N (NTf2)] by mixing the neat, liquid starting materials afforded the corresponding 2-(trimethylsilyl)imidazolium salts [()SiMe3]X as highly reactive, white crystalline solids. Only the triflimidate (X = NTf2) proved to be stable in solution and could be characterized by means of NMR spectroscopy (in C6D5Br) and X-ray diffraction analysis, whereas dissociation into free and Me3SiOTf was observed for the triflate system, in agreement with the trend derived by DFT calculations; the iodide was too insoluble for characterization. The compounds [()SiMe3]X showed the reactivity expected for frustrated carbene-silylium pairs, and treatment with carbon dioxide, tert-butyl isocyanate and diphenylbutadiyne gave the 1,2-addition products [()CO2SiMe3]X (X = I, OTf, NTf2), [()C(NtBu)OSiMe3]OTf and [()C(Ph)C(SiMe3)CCPh]OTf, respectively. Upon reaction with [AuCl(PPh3)], metal-chloride bond activation was observed, with formation of the cationic gold(i) complexes [()Au(PPh3)]X (X = OTf, NTf2). PMID:25912291

  15. 双圈图的代数连通度%On the algebraic connectivity of bicyclic graphs

    Institute of Scientific and Technical Information of China (English)

    袁西英; 张丽; 孙玉芹

    2007-01-01

    Bicyclic graphs are connected graphs in which the number of edges equals the number of vertices plus one.The aothors study the algebraic connectivity α(G)of a bicyclic graph G on n vertices and prove that α(G)≤1 for all bicyclic graphs G on n(n≥10)vertices.Funhermore they determine all the bicyclic graphs G on n(,n≥10)vertices such that α(G)=1.%边数等于点数加1的连通图称为双圈图.研究双圈图G的代数连通度,记作α(G),证明了结论:对所有的n(n≥10)阶双圈图G都有α(G)≤1成立,并且确定了满足α(G)=1的所有,n(n≥10)阶双圈图.

  16. 一种电动车用锂电池剩余容量检测系统%A SOC detecting system for electric bicycle battery

    Institute of Scientific and Technical Information of China (English)

    赵庆河

    2012-01-01

    针对电动车应用中的需求,提出了一种电动车用锂电池剩余容量(SOC)检测的方法,并设计了一套SOC检测系统.该系统以AVR单片机为控制及计算核心、以ACS712为电流采集器,采用线性光耦隔离模拟电压信号,集合充放电电流对时间的积分和BP神经网络估算两种方法来测量电池SOC值.该系统具有成本低、安全可靠、计算准确等特点,适合在电动车上推广使用.%For electric bicycle application demand, a method of electric bicycle lithium battery state of charge (SOC) detection is proposed, and a SOC detection system is designed. The system is based on AVR MCU as the control and calculation core, used ACS712 as current collector. It uses a linearopto -isolator to insulate analog voltage signal. It measures SOC of the battery integrating two methods which are current integration to the time and BP neural network estimation. The system has the advantages of low cost, safe and reliable, accurate calculation and other characteristics. It is suitable for use in electric vehicles.

  17. "Bicycles May Use Full Lane" Signage Communicates U.S. Roadway Rules and Increases Perception of Safety.

    Science.gov (United States)

    Hess, George; Peterson, M Nils

    2015-01-01

    Many global challenges, including obesity, health care costs, and climate change, could be addressed in part by increasing the use of bicycles for transportation. Concern about the safety of bicycling on roadways is frequently cited as a deterrent to increasing bicycle use in the USA. The use of effective signage along roadways might help alleviate these concerns by increasing knowledge about the rights and duties of bicyclists and motorists, ideally reducing crashes. We administered a web-based survey, using Twitter for recruitment, to examine how well three US traffic control devices communicated the message that bicyclists are permitted in the center of the travel lane and do not have to "get out of the way" to allow motorists to pass without changing lanes: "Bicycles May Use Full Lane" and "Share the Road" signage, and Shared Lane Markings on the pavement. Each was compared to an unsigned roadway. We also asked respondents whether it was safe for a bicyclist to occupy the center of the travel lane. "Bicycles May Use Full Lane" signage was the most consistently comprehended device for communicating the message that bicyclists may occupy the travel lane and also increased perceptions of safety. "Share the Road" signage did not increase comprehension or perceptions of safety. Shared Lane Markings fell somewhere between. "Bicycles May Use Full Lane" signage showed notable increases in comprehension among novice bicyclists and private motor vehicle commuters, critical target audiences for efforts to promote bicycling in the USA. Although limited in scope, our survey results are indicative and suggest that Departments of Transportation consider replacing "Share the Road" with "Bicycles May Use Full Lane" signage, possibly combined with Shared Lane Markings, if the intent is to increase awareness of roadway rights and responsibilities. Further evaluation through virtual reality simulations and on-road experiments is merited.

  18. "Bicycles May Use Full Lane" Signage Communicates U.S. Roadway Rules and Increases Perception of Safety.

    Directory of Open Access Journals (Sweden)

    George Hess

    Full Text Available Many global challenges, including obesity, health care costs, and climate change, could be addressed in part by increasing the use of bicycles for transportation. Concern about the safety of bicycling on roadways is frequently cited as a deterrent to increasing bicycle use in the USA. The use of effective signage along roadways might help alleviate these concerns by increasing knowledge about the rights and duties of bicyclists and motorists, ideally reducing crashes. We administered a web-based survey, using Twitter for recruitment, to examine how well three US traffic control devices communicated the message that bicyclists are permitted in the center of the travel lane and do not have to "get out of the way" to allow motorists to pass without changing lanes: "Bicycles May Use Full Lane" and "Share the Road" signage, and Shared Lane Markings on the pavement. Each was compared to an unsigned roadway. We also asked respondents whether it was safe for a bicyclist to occupy the center of the travel lane. "Bicycles May Use Full Lane" signage was the most consistently comprehended device for communicating the message that bicyclists may occupy the travel lane and also increased perceptions of safety. "Share the Road" signage did not increase comprehension or perceptions of safety. Shared Lane Markings fell somewhere between. "Bicycles May Use Full Lane" signage showed notable increases in comprehension among novice bicyclists and private motor vehicle commuters, critical target audiences for efforts to promote bicycling in the USA. Although limited in scope, our survey results are indicative and suggest that Departments of Transportation consider replacing "Share the Road" with "Bicycles May Use Full Lane" signage, possibly combined with Shared Lane Markings, if the intent is to increase awareness of roadway rights and responsibilities. Further evaluation through virtual reality simulations and on-road experiments is merited.

  19. Perceiving and Acting on Complex Affordances: How Children and Adults Bicycle Across Two Lanes of Opposing Traffic

    OpenAIRE

    Grechkin, Timofey Y.; Chihak, Benjamin J.; Cremer, James F.; Kearney, Joseph K.; Plumert, Jodie M.

    2012-01-01

    This investigation examined how children and adults negotiate a challenging perceptual-motor problem with significant real-world implications – bicycling across two lanes of opposing traffic. Twelve- and 14-year-olds and adults rode a bicycling simulator through an immersive virtual environment. Participants crossed intersections with continuous cross traffic coming from opposing directions. Opportunities for crossing were divided into aligned (far gap opens with or before near gap) and rolli...

  20. The risk of pediatric bicycle handlebar injury compared with non-handlebar injury: a retrospective multicenter study in Osaka, Japan

    OpenAIRE

    Hirose, Tomoya; Ogura, Hiroshi; Kiguchi, Takeyuki; Mizushima, Yasuaki; Kimbara, Futoshi; Shimazaki, Junya; Shiono, Shigeru; Yamamura, Hitoshi; Wakai, Akinori; Takegawa, Ryosuke; Matsumoto, Hisatake; Ohnishi, Mitsuo; Shimazu, Takeshi

    2015-01-01

    Background Bicycle accidents are one of the major causes of unintentional traumatic injury in childhood. The purpose of this study was to examine characteristics and risks of handlebar injury in childhood. Methods We conducted a more than 5-year retrospective survey of patients under 15 years of age with bicycle-related injuries admitted to eight urban tertiary emergency centers in Osaka, Japan. Patients were divided into the direct-impact handlebar injury (HI) group and the non-handlebar inj...

  1. Bulky N-Phosphino-Functionalized N-Heterocyclic Carbene Ligands: Synthesis, Ruthenium Coordination Chemistry, and Ruthenium Alkylidene Complexes for Olefin Metathesis.

    Science.gov (United States)

    Brown, Christopher C; Rominger, Frank; Limbach, Michael; Hofmann, Peter

    2015-11-01

    Ruthenium chemistry and applications in catalytic olefin metathesis based on N-phosphino-functionalized N-heterocyclic carbene ligands (NHCPs) are presented. Alkyl NHCP Ru coordination chemistry is described, and access to several potential synthetic precursors for ruthenium alkylidene complexes is outlined, incorporating both trimethylsilyl and phenyl alkylidenes. The Ru alkylidene complexes are evaluated as potential olefin metathesis catalysts and were shown to behave in a latent fashion. They displayed catalytic activity at elevated temperatures for both ring closing metathesis and ring opening metathesis polymerization. PMID:26479425

  2. Bulky N-Phosphino-Functionalized N-Heterocyclic Carbene Ligands: Synthesis, Ruthenium Coordination Chemistry, and Ruthenium Alkylidene Complexes for Olefin Metathesis.

    Science.gov (United States)

    Brown, Christopher C; Rominger, Frank; Limbach, Michael; Hofmann, Peter

    2015-11-01

    Ruthenium chemistry and applications in catalytic olefin metathesis based on N-phosphino-functionalized N-heterocyclic carbene ligands (NHCPs) are presented. Alkyl NHCP Ru coordination chemistry is described, and access to several potential synthetic precursors for ruthenium alkylidene complexes is outlined, incorporating both trimethylsilyl and phenyl alkylidenes. The Ru alkylidene complexes are evaluated as potential olefin metathesis catalysts and were shown to behave in a latent fashion. They displayed catalytic activity at elevated temperatures for both ring closing metathesis and ring opening metathesis polymerization.

  3. Synthesis and Regioselective Reaction of Some Unsymmetrical Heterocyclic Chalcone Derivatives and Spiro Heterocyclic Compounds as Antibacterial Agents

    Directory of Open Access Journals (Sweden)

    Maher A. El-Hashash

    2015-12-01

    Full Text Available A number of novel heterocyclic chalcone derivatives can be synthesized by thermal and microwave tools. Treatment of 4-(4-Acetylamino- and/or 4-bromo-phenyl-4-oxobut-2-enoic acids with hydrogen peroxide in alkaline medium were afforded oxirane derivatives 2. Reaction of the epoxide 2 with 2-amino-5-aryl-1,3,4-thiadiazole derivatives yielded chalcone of imidazo[2,1-b]thiadiazole derivative 4 via two thermal routes. In one pot reaction of 4-bromoacetophenone, diethyloxalate, and 2-amino-5-aryl-1,3,4-thiadiazole derivatives in MW irradiation (W 250 and T 150 °C under eco-friendly conditions afforded an unsuitable yield of the desired chalcone 4d. The chalcone derivatives 4 were used as a key starting material to synthesize some new spiroheterocyclic compounds via Michael and aza-Michael adducts. The chalcone 4f was similar to the aryl-oxo-vinylamide derivatives for the inhibition of tyrosine kinase and cancer cell growth. The electron-withdrawing substituents, such as halogens, and 2-amino-1,3,4-thiadiazole moeity decreasing the electron density, thereby decreasing the energy of HOMO, and the presence of imidazothiadiazole moiety should improve the antibacterial activity. Thus, the newly synthesized compounds were evaluated for their anti-bacterial activity against (ATCC 25923, (ATCC 10987, (ATCC 274, and (SM514. The structure of the newly synthesized compounds was confirmed by elemental analysis and spectroscopic data.

  4. Synthesis and Regioselective Reaction of Some Unsymmetrical Heterocyclic Chalcone Derivatives and Spiro Heterocyclic Compounds as Antibacterial Agents.

    Science.gov (United States)

    El-Hashash, Maher A; Rizk, Sameh A; Atta-Allah, Saad R

    2015-01-01

    A number of novel heterocyclic chalcone derivatives can be synthesized by thermal and microwave tools. Treatment of 4-(4-Acetylamino- and/or 4-bromo-phenyl)-4-oxobut-2-enoic acids with hydrogen peroxide in alkaline medium were afforded oxirane derivatives 2. Reaction of the epoxide 2 with 2-amino-5-aryl-1,3,4-thiadiazole derivatives yielded chalcone of imidazo[2,1-b]thiadiazole derivative 4 via two thermal routes. In one pot reaction of 4-bromoacetophenone, diethyloxalate, and 2-amino-5-aryl-1,3,4-thiadiazole derivatives in MW irradiation (W 250 and T 150 °C) under eco-friendly conditions afforded an unsuitable yield of the desired chalcone 4d. The chalcone derivatives 4 were used as a key starting material to synthesize some new spiroheterocyclic compounds via Michael and aza-Michael adducts. The chalcone 4f was similar to the aryl-oxo-vinylamide derivatives for the inhibition of tyrosine kinase and cancer cell growth. The electron-withdrawing substituents, such as halogens, and 2-amino-1,3,4-thiadiazole moeity decreasing the electron density, thereby decreasing the energy of HOMO, and the presence of imidazothiadiazole moiety should improve the antibacterial activity. Thus, the newly synthesized compounds were evaluated for their anti-bacterial activity against (ATCC 25923), (ATCC 10987), (ATCC 274,) and (SM514). The structure of the newly synthesized compounds was confirmed by elemental analysis and spectroscopic data. PMID:26690393

  5. Asymmetric allylic alkylation in combination with ring-closing metathesis for the preparation of chiral N-heterocycles

    NARCIS (Netherlands)

    Teichert, Johannes F.; Zhang, Suyan; Zijl, Anthoni W. van; Slaa, Jan Willem; Minnaard, Adriaan J.; Feringa, Bernard

    2010-01-01

    Asymmetric copper-catalyzed allylic substitution with methylmagnesium bromide is employed in combination with ring-closing olefin metathesis or ene-yne metathesis to achieve the synthesis of chiral, unsaturated nitrogen heterocycles. The resulting six- to eight-membered chiral heterocycles are acces

  6. The Bicycle – Future’s Solution for an Eco-friendly Urban Transport

    Directory of Open Access Journals (Sweden)

    Cristina Ciovică

    2012-05-01

    Full Text Available Even though more and more cities across the globe impose restrictive measures regarding theuse of cars and offer instead incentives in order to choose alternative means of transport, they do not slowdown their economic growth, but on the contrary they prove their skills towards providing citizens a betterlife. Under these circumstances, the bicycle appears as a viable solution for most of us, and the publicprograms that support its use have started to develop globally, at European level, and in Romania as well.The current paper wishes to point out the stimulating perspectives brought by the slight increase in thenumber of bicycles sold in our country in recent years towards the future of urban transport.

  7. Study of Drive Mechanisms of Bicycle, Tricycle or Like Vehicles to Optimize Operating Performance - A Review

    Directory of Open Access Journals (Sweden)

    Rahul U. Urunkar

    2014-01-01

    Full Text Available A cycle or cycle rickshaw is a small-scale local means of transport. Cycle rickshaws are human-powered, a type of tricycle designed to carry passengers in addition to the driver. Tricycles are used primarily for commercial transportation. Various locally made configurations of bicycle or tricycle are available. The present form of cycle has many shortcomings. One of the major problems faced by available bicycle or tricycle is its less efficiency or mechanical advantage. This paper reviews patent (which are now open for public access and experimental work brought by researchers on drive mechanism of cycle in order to optimize its operating performance. An individual idea or any possible combination of different ideas can be used for optimizing performance of driving mechanism for cycle.

  8. 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. PMID:26739323

  9. Optimal design parameters of the bicycle-rider system for maximal muscle power output.

    Science.gov (United States)

    Yoshihuku, Y; Herzog, W

    1990-01-01

    The purpose of this study was to find the optimal values of design parameters for a bicycle-rider system (crank length, pelvic inclination, seat height, and rate of crank rotation) which maximize the power output from muscles of the human lower limb during bicycling. The human lower limb was modelled as a planar system of five rigid bodies connected by four smooth pin joints and driven by seven functional muscle groups. The muscles were assumed to behave according to an adapted form of Hill's equation. The dependence of the average power on the design parameters was examined. The instantaneous power of each muscle group was studied and simultaneous activity of two seemingly antagonistic muscle groups was analyzed. Average peak power for one full pedal revolution was found to be around 1100 W. The upper body position corresponding to this peak power output was slightly reclined, and the pedalling rate was 155 rpm for a nominal crank length of 170 mm.

  10. Is the three-foot bicycle passing law working in Baltimore, Maryland?

    Science.gov (United States)

    Love, David C; Breaud, Autumn; Burns, Sean; Margulies, Jared; Romano, Max; Lawrence, Robert

    2012-09-01

    Maryland (MD) recently became one of fourteen states in the United States to enact a traffic law requiring motor vehicles to pass bicyclists at a distance of greater than three feet. To our knowledge, motorist compliance with the law has never been assessed. This study measured the distance between overtaking motor vehicles and cyclists [e.g. vehicle passing distance (VPD)], to develop baseline metrics for tracking implementation of the three-foot passing law in Baltimore, MD and to assess risk factors for dangerous passes. During September and October 2011, cyclists (n=5) measured VPD using a previously published video technique (Parkin and Meyers, 2010). Cyclists logged a total of 10.8h of video footage and 586 vehicle passes on 34 bicycle commuting trips. The average trip lasted 19.5±4.9 min and cyclists were passed on average 17.2±11.8 times per trip. VPDs of three feet or less were common when cycling in standard lanes (17%; 78 of 451 passes) and lanes with a shared lane marking (e.g. sharrows) (23%; 11 of 47 passes). No passes of three feet or less occurred in bicycle lanes (0 of 88 passes). A multiple linear regression model was created, which explained 26% of the variability in VPD. Significant model variables were lane width, bicycle infrastructure, cyclist identity, and street identity. Interventions, such as driver education, signage, enforcement, and bicycle infrastructure changes are needed to influence driving behavior in Baltimore to increase motorist compliance with the three-foot law. PMID:22664711

  11. Automatic control of cycling effort using electric bicycles and mobile devices

    OpenAIRE

    Jose A. Afonso; Rodrigues, Filipe J.; Delfim Pedrosa; Joao L. Afonso

    2015-01-01

    This paper describes the development and evaluation of a novel effort control system for cycling, which contributes to promote the users’ mobility and physical health. This system provides automatic control of the motor assistance level of an electric bicycle in order to ensure that the cyclist’s effort remains inside the desired target zone, regardless of changes in other variables which normally affect the effort, such as the slope of the road. The system presented in this paper controls th...

  12. A Universal Design Method for Reflecting Physical Characteristics Variability: Case Study of a Bicycle Frame.

    Science.gov (United States)

    Shimada, Masato; Suzuki, Wataru; Yamada, Shuho; Inoue, Masato

    2016-01-01

    To achieve a Universal Design, designers must consider diverse users' physical and functional requirements for their products. However, satisfying these requirements and obtaining the information which is necessary for designing a universal product is very difficult. Therefore, we propose a new design method based on the concept of set-based design to solve these issues. This paper discusses the suitability of proposed design method by applying bicycle frame design problem. PMID:27534334

  13. The Regional Response to Federal Fundingfor Bicycle and Pedestrian Projects: Executive Summary

    OpenAIRE

    McCann, Barbara; McRee, Lanier; Handy, Susan L; Meharg, Emily; Bailey, Linda; Ewing, Reid; Ernst, Michelle; Wright, Kate

    2009-01-01

    Since its initiation in the early 20th century, the federal transportation funding program has focused on highway construction for automobile travel. In the last few decades, public transportation has received 20% of federal resources, a significant share, but non-motorized modes such as bicycling and walking have historically received very limited funding. Over the past three decades, however, views of non-motorized modes and the federal interest in promoting them have changed dramatically. ...

  14. A simple, enaminone-based approach to some bicyclic pyridazinium tetrafluoroborates

    OpenAIRE

    František Josefík; Markéta Svobodová; Valerio Bertolasi; Petr Šimůnek

    2013-01-01

    Easily obtainable cyclic enaminones (piperidin-2-ylidenealkanones) can be transformed into substituted bicyclic pyridazinium tetrafluoroborates upon treatment with corresponding diazonium salts. The transformation can be performed either in a one-pot way or in a two-step process with the isolation of single azo-coupled enaminone as the intermediate. The former method is superior. Under the optimized conditions, a number of pyridazinium salts substituted with both electron-donating and electro...

  15. 'Cycle thieves, we are watching you': impact of a simple signage intervention against bicycle theft.

    Directory of Open Access Journals (Sweden)

    Daniel Nettle

    Full Text Available BACKGROUND: Bicycle theft is a serious problem in many countries, and there is a lack of evidence concerning effective prevention strategies. Displaying images of 'watching eyes' has been shown to make people behave in more socially desirable ways in a number of settings, but it is not yet clear if this effect can be exploited for purposes of crime prevention. We report the results of a simple intervention on a university campus where signs featuring watching eyes and a related verbal message were displayed above bicycle racks. METHODOLOGY AND PRINCIPAL FINDINGS: We installed durable signs at three locations which had experienced high levels of bicycle theft, and used the rest of the university campus as a control location. Reported thefts were monitored for 12 months before and after the intervention. Bicycle thefts decreased by 62% at the experimental locations, but increased by 65% in the control locations, suggesting that the signs were effective, but displaced offending to locations with no signs. The Odds Ratio for the effect of the intervention was 4.28 (95% confidence interval 2.04-8.98, a large effect compared to other place-based crime prevention interventions. CONCLUSIONS AND SIGNIFICANCE: The effectiveness of this extremely cheap and simple intervention suggests that there can be considerable crime-reduction benefits to engaging the psychology of surveillance, even in the absence of surveillance itself. Simple interventions for high-crime locations based on this principle should be considered as an adjunct to other measures, although a possible negative consequence is displacement of offending.

  16. A sketch planning methodology for determining interventions for bicycle and pedestrian crashes: an ecological approach

    OpenAIRE

    Thakuriah, P.; Cottrill, C.; Thomas, N; Vaughn, S.

    2010-01-01

    Bicycle and pedestrian safety planning have recently been gaining increased attention. With this focus, however, comes increased responsibilities for planning agencies and organizations tasked with evaluating and selecting safety interventions, a potentially arduous task given limited staff and resources. This study presents a sketch planning framework based on ecological factors that attempts to provide an efficient and effective method of selecting appropriate intervention measures. A Chica...

  17. Health effects of the London bicycle sharing system: health impact modelling study

    OpenAIRE

    Woodcock, James; Tainio, Marko; Cheshire, James; O’Brien, Oliver; Goodman, Anna

    2014-01-01

    Objective To model the impacts of the bicycle sharing system in London on the health of its users. Design Health impact modelling and evaluation, using a stochastic simulation model. Setting Central and inner London, England. Data sources Total population operational registration and usage data for the London cycle hire scheme (collected April 2011-March 2012), surveys of cycle hire users (collected 2011), and London data on travel, physical activity, road traffic collisions, and particulate ...

  18. Synthesis and Structure of A Novel Caged Bicyclic Phosphate Flame Retardant

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A novel caged bicyclic phosphate flame retardant tri(1-oxo-2,6,7-trioxa-l-phosphabicyclo [2.2.2] octane-methyl) phosphate (Trimer) was synthesized from 1-oxo-4-hydroxymethyl-2,6,7-trioxa-l-phosphabicyclo [2.2.2] octane (PEPA) and phosphorus oxychloride in this paper.Its structure was characterized by elemental analysis, FTIR, 1H NMR, 31P NMR and X-ray diffraction analysis.

  19. ω-Extension of Bicyclic Semigroup%双循环半群的ω扩张

    Institute of Scientific and Technical Information of China (English)

    朱雯; 詹亮

    2009-01-01

    In this paper,we discussed ω-extension of bicyclic semigroups.Two types of this extension are proposed.In §2 we discussed strong semilattice extension and the structure of the extension is well presented.In §3 we discussed another order extension.We proved that congruence lattice of this extension semigroups is union set of two sublattice.One is the group congruence semilattice,the other is the pure idempotent congruence semilattice.

  20. Two food-borne heterocyclic amines: Metabolism and DNA adduct formation of amino-alpha-carbolines

    DEFF Research Database (Denmark)

    Frederiksen, Hanne

    2005-01-01

    or proteins of animal or vegetable origin, furthermore they are found in many cooked foods, such as fish, meat, and chicken. The specific mutagenicity of the amino-a-carbolines are lower in the Ames Salmonella assay than other heterocyclic amines, but in rodent studies the carcinogenicity of the aminoa, alpha...... been studied. Characteristic for the amino-a-carbolines are that relatively large amounts of these compounds in rat and human hepatic microsomes are activated to potent carcinogenic compounds compared with other heterocyclic amines, but further in vivo studies of the amino-a-carbolines are needed...... to highlight these indications. In this review, the main characteristics with focus on the metabolism and the DNA-adduct formation of the amino-a-carbolines are described and compared with other heterocyclic amines....

  1. Selective Release of Aromatic Heterocycles from Ruthenium Tris(2-pyridylmethyl)amine with Visible Light

    Science.gov (United States)

    Li, Ao; White, Jessica K.; Arora, Karan; Herroon, Mackenzie K.; Martin, Philip D.; Schlegel, H. Bernhard; Podgorski, Izabela; Turro, Claudia; Kodanko, Jeremy J.

    2016-01-01

    Three complexes of the general formula [Ru(TPA)L2](PF6)2 [TPA = tris(2-pyridylmethyl)amine], where L = pyridine (1), nicotinamide (2), and imidazole (3), were prepared and characterized spectroscopically. X-ray crystallographic data were obtained for 1 and 3. Complexes 1–3 show strong absorption in the visible region and selective release of heterocycles upon irradiation with visible light. Time-dependent density functional theory calculations are consistent with the presence of singlet metal-to-ligand charge-transfer bands in the visible region in 1–3. Caged heterocycles 1–3 are highly stable in solution in the dark, including in cell growth media. Cell viability data show no signs of toxicity of 1–3 against PC-3 cells at concentrations up to 100 μM under light and dark conditions, consistent with Ru(TPA) acting as a nontoxic and effective photocaging group for aromatic heterocycles. PMID:26670781

  2. Synthetic and Structural Studies of N-Heterocyclic Carbene Complexes of Nickel

    Institute of Scientific and Technical Information of China (English)

    WANG,Jun-Wen; XU,Fang-Bo; LI,Qiang-Shan; SONG,Hai-Bin; LIU,Yong-Sheng; ZHANG,Zheng-Zhi

    2004-01-01

    @@ Transition metal complexes of stable N-heterocyclic carbenes have recently gained increasing attention as pre-catalysts for a number of important reactions primarily based on the analogy between N-heterocyclic carbenes and strong ó-donating tertiary phosphines,[1] Although a large number of transition-metal carbene complexes have been reported, very few incorporate chelating carbenes were reported.[2,3] Therefore, we have set out to prepare and study transition-metal compounds with chelating di-N-heterocyclic carbenes, and we now report new dicationic tetra(carbine)nickel(Ⅱ) complexes in this class (Scheme 1). Their structures have been determined by single-crystal X-ray diffraction studies (Figure 1).

  3. Enantioselective construction of quaternary N-heterocycles by palladium-catalysed decarboxylative allylic alkylation of lactams

    KAUST Repository

    Behenna, Douglas C.

    2011-12-18

    The enantioselective synthesis of nitrogen-containing heterocycles (N-heterocycles) represents a substantial chemical research effort and resonates across numerous disciplines, including the total synthesis of natural products and medicinal chemistry. In this Article, we describe the highly enantioselective palladium-catalysed decarboxylative allylic alkylation of readily available lactams to form 3,3-disubstituted pyrrolidinones, piperidinones, caprolactams and structurally related lactams. Given the prevalence of quaternary N-heterocycles in biologically active alkaloids and pharmaceutical agents, we envisage that our method will provide a synthetic entry into the de novo asymmetric synthesis of such structures. As an entry for these investigations we demonstrate how the described catalysis affords enantiopure quaternary lactams that intercept synthetic intermediates previously used in the synthesis of the Aspidosperma alkaloids quebrachamine and rhazinilam, but that were previously only available by chiral auxiliary approaches or as racemic mixtures. © 2012 Macmillan Publishers Limited. All rights reserved.

  4. Synthesis of Oxygen Heterocycles via Aromatic C-O Bond Formation Using Arynes

    Directory of Open Access Journals (Sweden)

    Hideto Miyabe

    2015-07-01

    Full Text Available Most of the synthetic approaches to the benzo-fused heterocycles containing an oxygen atom have involved the use of phenol derivatives as a starting material. This review highlights the new synthetic approaches involving the aromatic C-O bond-forming process using arynes. The insertion of arynes into the C=O bond gives the unstable intermediates, [2 + 2] cycloaddition-type adducts, which can be easily converted into a variety of oxygen atom-containing heterocycles in a single operation. In this review, the syntheses of oxygen heterocycles, such as coumarin, chromene, xanthene, dihydrobenzofuran and benzofuran derivatives, via the insertion of arynes into the C=O bond of aldehydes or formamides are summarized.

  5. Dearomatization Reactions of N-Heterocycles Mediated by Group 3 Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Kevin L [Univ. of California, Los Angeles, CA (United States); Williams, Bryan N [Univ. of California, Los Angeles, CA (United States); Benitez, Diego [California Inst. of Technology (CalTech), Pasadena, CA (United States); Carver, Colin T [Univ. of California, Los Angeles, CA (United States); Ogilby, Kevin R [Univ. of California, Los Angeles, CA (United States); Tkatchouk, Ekaterina [California Inst. of Technology (CalTech), Pasadena, CA (United States); Goddard, William A [California Inst. of Technology (CalTech), Pasadena, CA (United States); Diaconescu, Paula L [Univ. of California, Los Angeles, CA (United States)

    2010-01-13

    Group 3 (Sc, Y, Lu, La) benzyl complexes supported by a ferrocene diamide ligand are reactive toward aromatic N-heterocycles by mediating their coupling and, in a few cases, the cleavage of their C-N bonds. When these complexes reacted with 2,2'-bipyridine or isoquinoline, they facilitated the alkyl migration of the benzyl ligand onto the pyridine ring, a process accompanied by the dearomatization of the N-heterocycle. The products of the alkyl-transfer reactions act as hydrogen donors in the presence of aromatic N-heterocycles, ketones, and azobenzene. Experimental and computational studies suggest that the hydrogen transfer takes place through a concerted mechanism. An interesting disproportionation reaction of the dearomatized, alkyl-substituted isoquinoline complexes is also reported.

  6. Synthesis and Selective Cytotoxic Activities on Rhabdomyosarcoma and Noncancerous Cells of Some Heterocyclic Chalcones.

    Science.gov (United States)

    Do, Tuong-Ha; Nguyen, Dai-Minh; Truong, Van-Dat; Do, Thi-Hong-Tuoi; Le, Minh-Tri; Pham, Thanh-Quan; Thai, Khac-Minh; Tran, Thanh-Dao

    2016-01-01

    Chemically diverse heterocyclic chalcones were prepared and evaluated for cytotoxicity, aiming to push forward potency and selectivity. They were tested against rhabdomyosarcoma (RMS) and noncancerous cell line (LLC-PK1). The influence of heteroaryl patterns on rings A and B was studied. Heterocycle functionalities on both rings, such as phenothiazine, thiophene, furan and pyridine were evaluated. Notably, the introduction of three methoxy groups at positions 3, 4, 5 on ring B appears to be critical for cytotoxicity. The best compound, with potent and selective cytotoxicity (IC50 = 12.51 μM in comparison with the value 10.84 μM of paclitaxel), contains a phenothiazine moiety on ring A and a thiophene heterocycle on ring B. Most of the potential compounds only show weak cytoxicity on the noncancerous cell line LLC-PK1. PMID:27005608

  7. Synthesis and Selective Cytotoxic Activities on Rhabdomyosarcoma and Noncancerous Cells of Some Heterocyclic Chalcones

    Directory of Open Access Journals (Sweden)

    Tuong-Ha Do

    2016-03-01

    Full Text Available Chemically diverse heterocyclic chalcones were prepared and evaluated for cytotoxicity, aiming to push forward potency and selectivity. They were tested against rhabdomyosarcoma (RMS and noncancerous cell line (LLC-PK1. The influence of heteroaryl patterns on rings A and B was studied. Heterocycle functionalities on both rings, such as phenothiazine, thiophene, furan and pyridine were evaluated. Notably, the introduction of three methoxy groups at positions 3, 4, 5 on ring B appears to be critical for cytotoxicity. The best compound, with potent and selective cytotoxicity (IC50 = 12.51 μM in comparison with the value 10.84 μM of paclitaxel, contains a phenothiazine moiety on ring A and a thiophene heterocycle on ring B. Most of the potential compounds only show weak cytoxicity on the noncancerous cell line LLC-PK1.

  8. 自行车碟刹制动距离测试系统的设计与实现%Design and implementation of bicycle disc braking distance test system

    Institute of Scientific and Technical Information of China (English)

    陈梦群; 杨成忠

    2012-01-01

    system can accurately measure the bike's braking distance, and be stable to perform, easy to operate and practical. This set of test system for the bicycle disc brake has good application value.

  9. Silylation of C-H bonds in aromatic heterocycles by an Earth-abundant metal catalyst

    Science.gov (United States)

    Toutov, Anton A.; Liu, Wen-Bo; Betz, Kerry N.; Fedorov, Alexey; Stoltz, Brian M.; Grubbs, Robert H.

    2015-02-01

    Heteroaromatic compounds containing carbon-silicon (C-Si) bonds are of great interest in the fields of organic electronics and photonics, drug discovery, nuclear medicine and complex molecule synthesis, because these compounds have very useful physicochemical properties. Many of the methods now used to construct heteroaromatic C-Si bonds involve stoichiometric reactions between heteroaryl organometallic species and silicon electrophiles or direct, transition-metal-catalysed intermolecular carbon-hydrogen (C-H) silylation using rhodium or iridium complexes in the presence of excess hydrogen acceptors. Both approaches are useful, but their limitations include functional group incompatibility, narrow scope of application, high cost and low availability of the catalysts, and unproven scalability. For this reason, a new and general catalytic approach to heteroaromatic C-Si bond construction that avoids such limitations is highly desirable. Here we report an example of cross-dehydrogenative heteroaromatic C-H functionalization catalysed by an Earth-abundant alkali metal species. We found that readily available and inexpensive potassium tert-butoxide catalyses the direct silylation of aromatic heterocycles with hydrosilanes, furnishing heteroarylsilanes in a single step. The silylation proceeds under mild conditions, in the absence of hydrogen acceptors, ligands or additives, and is scalable to greater than 100 grams under optionally solvent-free conditions. Substrate classes that are difficult to activate with precious metal catalysts are silylated in good yield and with excellent regioselectivity. The derived heteroarylsilane products readily engage in versatile transformations enabling new synthetic strategies for heteroaromatic elaboration, and are useful in their own right in pharmaceutical and materials science applications.

  10. Pedaling into high gear for bicycle policy in Canada : lessons from bike summit 2008 in Toronto

    International Nuclear Information System (INIS)

    The 2008 bike summit provided a forum for the discussion of international and Canadian best practices related to bicycles and bicycling policy. The aim of the summit was to assist communities across Canada to improve conditions for cycling in the urban environment and help to generate a cultural shift towards greater acceptance of cycling on roads. This paper discussed lessons learned during the summit and outlined new methods of improving cycling in communities. The City of London has recently increased the amount of cyclists using its roads by 200 per cent. Cycling infrastructure is more affordable than constructing major public transit or road infrastructure. Savings in healthcare costs will be accrued over time as a result of the healthier lifestyles promoted by regular cycling activity. Bicycle trips can help to alleviate over-demand on heavy transit routes. Encouraging commuters to cycle will also reduce the amounts of greenhouse gases (GHGs) emitted in urban areas. Lane width reductions will help to reduce speeds as drivers are forced to pay more attention when driving. Public bike sharing programs and bike stations are now being used in many North American cities. It was concluded that strong advocacy is needed to ensure the growth and acceptance of cycling in urban centres. 23 figs

  11. Pharmacokinetics-pharmacodynamics analysis of bicyclic 4-nitroimidazole analogs in a murine model of tuberculosis.

    Directory of Open Access Journals (Sweden)

    Suresh B Lakshminarayana

    Full Text Available PA-824 is a bicyclic 4-nitroimidazole, currently in phase II clinical trials for the treatment of tuberculosis. Dose fractionation pharmacokinetic-pharmacodynamic studies in mice indicated that the driver of PA-824 in vivo efficacy is the time during which the free drug concentrations in plasma are above the MIC (fT>MIC. In this study, a panel of closely related potent bicyclic 4-nitroimidazoles was profiled in both in vivo PK and efficacy studies. In an established murine TB model, the efficacy of diverse nitroimidazole analogs ranged between 0.5 and 2.3 log CFU reduction compared to untreated controls. Further, a retrospective analysis was performed for a set of seven nitroimidazole analogs to identify the PK parameters that correlate with in vivo efficacy. Our findings show that the in vivo efficacy of bicyclic 4-nitroimidazoles correlated better with lung PK than with plasma PK. Further, nitroimidazole analogs with moderate-to-high volume of distribution and Lung to plasma ratios of >2 showed good efficacy. Among all the PK-PD indices, total lung T>MIC correlated the best with in vivo efficacy (rs = 0.88 followed by lung Cmax/MIC and AUC/MIC. Thus, lung drug distribution studies could potentially be exploited to guide the selection of compounds for efficacy studies, thereby accelerating the drug discovery efforts in finding new nitroimidazole analogs.

  12. Influence of roadway geometric elements on driver behavior when overtaking bicycles on rural roads

    Directory of Open Access Journals (Sweden)

    Jeremy R. Chapman

    2014-02-01

    Full Text Available The objective of this research was to determine what influence geometric design elements of roadway may have on driver behavior during the overtaking maneuver. This was part of a larger research effort to eliminate crashes (and the resulting fatalities and injuries between bicycles and motorized vehicles. The data collection process produced 1151 observations with approximately 40 different independent variables for each data point through direct observation, sensor logging, or derivation from other independent variables. Prior research by the authors developed a means to collect real-time field data through the use of a bicycle-mounted data collection system. The collected data was then used to model lateral clearance distance between vehicles and bicycles. The developed model confirmed field observations that the lateral clearance distance provided by drivers changes with vehicle speed and oncoming vehicle presence. These observations were presented by the authors previously. The model shows that driver behavior can be adjusted by the inclusion, or exclusion, of geometric elements. Evaluating roadways (or roadway designs based on this model will enable stakeholders to identify those roadway segments where a paved shoulder would prove an effective safety countermeasure. This research will also enable roadway designers to better identify during the design phase those roadway segments that should be constructed with a paved shoulder.

  13. Boris Loutzky – Creator of the world's first motorized bicycle classic layout with a combustion engine

    Directory of Open Access Journals (Sweden)

    Alexander Firsov

    2012-12-01

    Full Text Available The article is dedicated to creation of the first motor vehicles with internal combustion engines. The purpose of article is to establish the name of the designer who was the first to create the world's motorized bicycle classic layout with a combustion engine. This article describes the construction of the first motorized vehicles Gottlieb Daimler, Edward Butler, Felix Millet, Giuseppe Murniotti, Edward Pennington, Alois Wolfmüller and Hans Geisenhof. based on the analysis of structures of motor vehicles. It’s stated that none of the vehicles can be called a «prototype» of modern mopeds and motorcycles. Based on the research it was found that in Germany Russian engineer B. Loutzky was engaged in creation of motorized vehicles with internal combustion engines even before Hildebrand and Pennington. These motorized vehicles were exhibited in Palermo, Erfurt, Vienna, Prague, Lamberg, Stuttgart and other cities in Europe, and were acknowledged and rewarded with gold medals. The paper describes the design of the first motorized bicycle with a classic layout by B. Loutzky and design of the unique internal combustion engines, which B. Loutzky used in his first vehicles. Overall, based on the analysis of patents for inventions, literary and archival sources, the priority of the Russian engineer B. Loutzky in creation of the motorized bicycle classic layout with a combustion engine is established.

  14. Built environment effects on cyclist injury severity in automobile-involved bicycle crashes.

    Science.gov (United States)

    Chen, Peng; Shen, Qing

    2016-01-01

    This analysis uses a generalized ordered logit model and a generalized additive model to estimate the effects of built environment factors on cyclist injury severity in automobile-involved bicycle crashes, as well as to accommodate possible spatial dependence among crash locations. The sample is drawn from the Seattle Department of Transportation bicycle collision profiles. This study classifies the cyclist injury types as property damage only, possible injury, evident injury, and severe injury or fatality. Our modeling outcomes show that: (1) injury severity is negatively associated with employment density; (2) severe injury or fatality is negatively associated with land use mixture; (3) lower likelihood of injuries is observed for bicyclists wearing reflective clothing; (4) improving street lighting can decrease the likelihood of cyclist injuries; (5) posted speed limit is positively associated with the probability of evident injury and severe injury or fatality; (6) older cyclists appear to be more vulnerable to severe injury or fatality; and (7) cyclists are more likely to be severely injured when large vehicles are involved in crashes. One implication drawn from this study is that cities should increase land use mixture and development density, optimally lower posted speed limits on streets with both bikes and motor vehicles, and improve street lighting to promote bicycle safety. In addition, cyclists should be encouraged to wear reflective clothing. PMID:26609666

  15. A Geo-Aware and VRP-Based Public Bicycle Redistribution System

    Directory of Open Access Journals (Sweden)

    J. H. Lin

    2012-01-01

    Full Text Available Public Bicycle System (PBS has been developed for short-distance transportation as a part of the mass transportation system. The supply and demand of bikes in PBS is usually unbalanced at different stations and needs to be continuously and widely monitored and redistributed. The bicycle redistribution is a part of the vehicle routing problem (VRP. We can apply solutions to the VRP to redistribute bicycle efficiently. However, most solutions to the VRP use the Euclidean distance as the condition factor, which does not take road conditions, traffic regulations, and geographical factors into account, resulting in unnecessary waste of delivery time and human resources. In this work, we propose an actual path distance optimization method for the VRP to adapt the several additional constraints of road problems. We also implement a system that integrates real-time station information, Web GIS, the urban road network, and heuristics algorithms for PBS. The system includes a simulator inside that can assist PBS managers to do the route planning efficiently and find the best scheduling strategy to achieve hotspot analysis and the adjustment of station deployment strategies to reduce PBS operation cost.

  16. The effect of alcohol hangover on the ability to ride a bicycle.

    Science.gov (United States)

    Hartung, Benno; Schwender, Holger; Mindiashvili, Nona; Ritz-Timme, Stefanie; Malczyk, Axel; Daldrup, Thomas

    2015-07-01

    To investigate the effects of alcohol on the ability to ride a bicycle, practical cycling tests were carried out at different blood alcohol concentrations (BAC). For this purpose, various alcoholic beverages could be consumed from around 2 p.m. until 11 p.m. Afterwards, the test persons spent the night on the trial site and were provided with dormitory sleeping accommodation. On the following morning, beginning at around 8 a.m., a final cycling test was performed. The performances of those test persons who had returned to state of soberness and of those with residual blood alcohol levels were compared to the performances on the day before. The practical ability to ride a bicycle was significantly reduced in the postalcoholic state compared to the rides of the day before. The relative cycling performance in the postalcoholic state was comparable to the rides under the influence of BAC of around 0.30 g/kg. There were no remarkable differences between the groups with and without residual blood alcohol levels regarding the rides on the next morning. Therefore, it can be assumed that the direct influence of residual blood alcohol levels plays a minor role for the ability to ride a bicycle in the postalcoholic state. Instead, the side effects of the high amounts of alcohol that were consumed the night before are crucial. PMID:25940454

  17. Study of electrode slice forming of bicycle dynamo hub power connector

    Science.gov (United States)

    Chen, Dyi-Cheng; Jao, Chih-Hsuan

    2013-12-01

    Taiwan's bicycle industry has been an international reputation as bicycle kingdom, but the problem in the world makes global warming green energy rise, the development of electrode slice of hub dynamo and power output connector to bring new hope to bike industry. In this study connector power output to gather public opinion related to patent, basis of collected documents as basis for design, structural components in least drawn to power output with simple connector. Power output of this study objectives connector hope at least cost, structure strongest, highest efficiency in output performance characteristics such as use of computer-aided drawing software Solid works to establish power output connector parts of 3D model, the overall portfolio should be considered part types including assembly ideas, weather resistance, water resistance, corrosion resistance to vibration and power flow stability. Moreover the 3D model import computer-aided finite element analysis software simulation of expected the power output of the connector parts manufacturing process. A series of simulation analyses, in which the variables relied on first stage and second stage forming, were run to examine the effective stress, effective strain, press speed, and die radial load distribution when forming electrode slice of bicycle dynamo hub.

  18. Built environment effects on cyclist injury severity in automobile-involved bicycle crashes.

    Science.gov (United States)

    Chen, Peng; Shen, Qing

    2016-01-01

    This analysis uses a generalized ordered logit model and a generalized additive model to estimate the effects of built environment factors on cyclist injury severity in automobile-involved bicycle crashes, as well as to accommodate possible spatial dependence among crash locations. The sample is drawn from the Seattle Department of Transportation bicycle collision profiles. This study classifies the cyclist injury types as property damage only, possible injury, evident injury, and severe injury or fatality. Our modeling outcomes show that: (1) injury severity is negatively associated with employment density; (2) severe injury or fatality is negatively associated with land use mixture; (3) lower likelihood of injuries is observed for bicyclists wearing reflective clothing; (4) improving street lighting can decrease the likelihood of cyclist injuries; (5) posted speed limit is positively associated with the probability of evident injury and severe injury or fatality; (6) older cyclists appear to be more vulnerable to severe injury or fatality; and (7) cyclists are more likely to be severely injured when large vehicles are involved in crashes. One implication drawn from this study is that cities should increase land use mixture and development density, optimally lower posted speed limits on streets with both bikes and motor vehicles, and improve street lighting to promote bicycle safety. In addition, cyclists should be encouraged to wear reflective clothing.

  19. A solid solution to a conjecture on the maximal energy of bipartite bicyclic graphs

    CERN Document Server

    Huo, Bofeng; Li, Xueliang; Shi, Yongtang

    2011-01-01

    The energy of a simple graph $G$, denoted by $E(G)$, is defined as the sum of the absolute values of all eigenvalues of its adjacency matrix. Let $C_n$ denote the cycle of order $n$ and $P^{6,6}_n$ the graph obtained from joining two cycles $C_6$ by a path $P_{n-12}$ with its two leaves. Let $\\mathscr{B}_n$ denote the class of all bipartite bicyclic graphs but not the graph $R_{a,b}$, which is obtained from joining two cycles $C_a$ and $C_b$ ($a, b\\geq 10$ and $a \\equiv b\\equiv 2\\, (\\,\\textmd{mod}\\, 4)$) by an edge. In [I. Gutman, D. Vidovi\\'{c}, Quest for molecular graphs with maximal energy: a computer experiment, {\\it J. Chem. Inf. Sci.} {\\bf41}(2001), 1002--1005], Gutman and Vidovi\\'{c} conjectured that the bicyclic graph with maximal energy is $P^{6,6}_n$, for $n=14$ and $n\\geq 16$. In [X. Li, J. Zhang, On bicyclic graphs with maximal energy, {\\it Linear Algebra Appl.} {\\bf427}(2007), 87--98], Li and Zhang showed that the conjecture is true for graphs in the class $\\mathscr{B}_n$. However, they could not...

  20. Facile synthesis, characterization and antimicrobial activities of diphenylphosphoryl derivatives of substituted aryl and nitrogen heterocycles

    Directory of Open Access Journals (Sweden)

    G. Subba Reddy

    2013-03-01

    Full Text Available Diphenylphosphoryl derivatives of substituted aryl and nitrogen heterocycles were prepared by a one-pot process involving sequential reaction of diphenylphosphine chloride with dry methyl alcohol/ethyl alcohol and then with different halides of substituted nitrogen heterocycles/aryl halides. The title compounds (5a-j structures were established by analytical, IR, NMR ( 1H, 13C and 31P and mass spectra, and they have been screened for their antimicrobial activity. They exhibited significant antibacterial and antifungal activity.

  1. Olefin Metathesis With Ruthenium-Arene Catalysts Bearing N-Heterocyclic Carbene Ligands

    Science.gov (United States)

    Delaude, Lionel; Demonceau, Albert

    In this chapter, we summarize the main results of our investigations on the ring-opening metathesis polymerization (ROMP) of cyclooctene catalyzed by various ruthenium (Ru)-arene complexes bearing imidazolin-2-ylidene, imidazolidin- 2-ylidene, or triazolin-5-ylidene ligands. Three major findings emerged from this study. First, we underscored the intervention of a photochemical activation step due to visible light illumination. Second, we established that the presence of an endocyclic double bond in the carbene ligand central heterocycle was not crucial to achieve high catalytic efficiencies. Third, we demonstrated that ortho-metallation of the N-heterocyclic carbene (NHC) ligand by the Ru center led to inactive catalysts.

  2. Formation and Human Risk of Carcinogenic Heterocyclic Amines Formed from Natural Precursors in Meat

    Energy Technology Data Exchange (ETDEWEB)

    Knize, M G; Felton, J S

    2004-11-22

    A group of heterocyclic amines that are mutagens and rodent carcinogens form when meat is cooked to medium and well-done states. The precursors of these compounds are natural meat components: creatinine, amino acids and sugars. Defined model systems of dry-heated precursors mimic the amounts and proportions of heterocyclic amines found in meat. Results from model systems and cooking experiments suggest ways to reduce their formation and, thus, to reduce human intake. Human cancer epidemiology studies related to consumption of well-done meat products are listed and compared.

  3. Rapid Kinetics and Relative Reactivity of Some Five Membered Aromatic Heterocycles using Hydrodynamic Voltammetry

    Directory of Open Access Journals (Sweden)

    S. B. Walke

    2015-12-01

    Full Text Available Kinetics of the bromination of imidazole, pyrazole and thiazole by molecular bromine and N-bromosuccinimide has been studied in aqueous medium. Since the reactions are rapid special technique namely, hydrodyanamic voltammetry has been employed to follow the course of the reactions. These reactions follow second order kinetics. The comparative kinetic data determines the reactivity order for these heterocycles towards the bromination using two different brominating reagents. The study justifies the stereochemical principles ascertaining the relative reactivity of these heterocycles quantitatively using kinetics as an investigational tool.

  4. Late-stage functionalization of biologically active heterocycles through photoredox catalysis.

    Science.gov (United States)

    Dirocco, Daniel A; Dykstra, Kevin; Krska, Shane; Vachal, Petr; Conway, Donald V; Tudge, Matthew

    2014-05-01

    The direct CH functionalization of heterocycles has become an increasingly valuable tool in modern drug discovery. However, the introduction of small alkyl groups, such as methyl, by this method has not been realized in the context of complex molecule synthesis since existing methods rely on the use of strong oxidants and elevated temperatures to generate the requisite radical species. Herein, we report the use of stable organic peroxides activated by visible-light photoredox catalysis to achieve the direct methyl-, ethyl-, and cyclopropylation of a variety of biologically active heterocycles. The simple protocol, mild reaction conditions, and unique tolerability of this method make it an important tool for drug discovery.

  5. Synthetic and Mechanistic Studies of Strained Heterocycle Opening Reactions Mediated by Zirconium(IV) Imido Complexes

    OpenAIRE

    Blum, Suzanne A.; Rivera, Vicki A.; Ruck, Rebecca T.; Michael, Forrest E.; Bergman, Robert G.

    2005-01-01

    The reactions of the bis(cyclopentadienyl)(tert-butylimido)zirconium complex (Cp2Zr=N-t-Bu)(THF) (1) with epoxides, aziridines, and episulfides were investigated. Heterocycles without accessible β-hydrogens undergo insertion/protonation of the C–X bond to produce 1,2-amino alcohols (X = O) and 1,2-diamines (X = NR), whereas heterocycles with accessible β-hydrogens undergo elimination/protonation to produce allylic alcohols (X = O) and allylic sulfides (X = S). Mechanistic investigations suppo...

  6. The impact of transportation infrastructure on bicycling injuries and crashes: a review of the literature

    Directory of Open Access Journals (Sweden)

    Cripton Peter A

    2009-10-01

    Full Text Available Abstract Background Bicycling has the potential to improve fitness, diminish obesity, and reduce noise, air pollution, and greenhouse gases associated with travel. However, bicyclists incur a higher risk of injuries requiring hospitalization than motor vehicle occupants. Therefore, understanding ways of making bicycling safer and increasing rates of bicycling are important to improving population health. There is a growing body of research examining transportation infrastructure and the risk of injury to bicyclists. Methods We reviewed studies of the impact of transportation infrastructure on bicyclist safety. The results were tabulated within two categories of infrastructure, namely that at intersections (e.g. roundabouts, traffic lights or between intersections on "straightaways" (e.g. bike lanes or paths. To assess safety, studies examining the following outcomes were included: injuries; injury severity; and crashes (collisions and/or falls. Results The literature to date on transportation infrastructure and cyclist safety is limited by the incomplete range of facilities studied and difficulties in controlling for exposure to risk. However, evidence from the 23 papers reviewed (eight that examined intersections and 15 that examined straightaways suggests that infrastructure influences injury and crash risk. Intersection studies focused mainly on roundabouts. They found that multi-lane roundabouts can significantly increase risk to bicyclists unless a separated cycle track is included in the design. Studies of straightaways grouped facilities into few categories, such that facilities with potentially different risks may have been classified within a single category. Results to date suggest that sidewalks and multi-use trails pose the highest risk, major roads are more hazardous than minor roads, and the presence of bicycle facilities (e.g. on-road bike routes, on-road marked bike lanes, and off-road bike paths was associated with the lowest

  7. New Palladium-Catalyzed Approaches to Heterocycles and Carbocycles

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Qinhua [Iowa State Univ., Ames, IA (United States)

    2004-12-19

    The tert-butylimines of o-(1-alkynyl)benzaldehydes and analogous pyridinecarbaldehydes have been cyclized under very mild reaction conditions in the presence of I2, ICl, PhSeCl, PhSCl and p-O2NC6H4SCl to give the corresponding halogen-, selenium- and sulfur-containing disubstituted isoquinolines and naphthyridines, respectively. Monosubstituted isoquinolines and naphthyridines have been synthesized by the metal-catalyzed ring closure of these same iminoalkynes. This methodology accommodates a variety of iminoalkynes and affords the anticipated heterocycles in moderate to excellent yields. The Pd(II)-catalyzed cyclization of 2-(1-alkynyl)arylaldimines in the presence of various alkenes provides an efficient way to synthesize a variety of 4-(1-alkenyl)-3-arylisoquinolines in moderate to excellent yields. The introduction of an ortho-methoxy group on the arylaldimine promotes the Pd-catalyzed cyclization and stabilizes the resulting Pd(II) intermediate, improving the yields of the isoquinoline products. Highly substituted naphthalenes have been synthesized by the palladium-catalyzed annulation of a variety of internal alkynes, in which two new carbon-carbon bonds are formed in a single step under relatively mild reaction conditions. This method has also been used to synthesize carbazoles, although a higher reaction temperature is necessary. The process involves arylpalladation of the alkyne, followed by intramolecular Heck olefination and double bond isomerization. This method accommodates a variety of functional groups and affords the anticipated highly substituted naphthalenes and carbazoles in good to excellent yields. Novel palladium migratiodarylation methodology for the synthesis of complex fused polycycles has been developed, in which one or more sequential Pd-catalyzed intramolecular migration processes involving C-H activation are employed. The chemistry works best with electron-rich aromatics, which is in agreement

  8. Synthesis of a New Class of Highly Functionalized Phosphorus Ylides Containing Heterocyclic Compounds

    Institute of Scientific and Technical Information of China (English)

    Shaabani Ahmad; Keshipour Sajjad; Aghaei Morteza; Khodabandeh M. Hassan; Zahedi Mansour

    2012-01-01

    The zwitterionic intermediate generated from the reaction of triphenylphosphine with electron deficient acety- lenic compounds was trapped by various NH acids. The synthesis resulted in a new class of highly functionalized heterocyclic compounds. Some of the reactions produced E and Z isomers. And the stability and transformation of them were studied by dynamic 1H NMR and density functional theory (DFT) calculations.

  9. "Decarbonization" of an imino N-heterocyclic carbene via triple benzyl migration from hafnium

    Science.gov (United States)

    An imino N-heterocyclic carbene underwent three sequential benzyl migrations upon reaction with tetrabenzylhafnium, resulting in complete removal of the carbene carbon from the ligand. The resulting eneamido-amidinato hafnium complex showed alkene polymerization activity comparable to that of a prec...

  10. Solid-phase Synthesis of a Novel Kind of Hydroxylated Heterocyclic Ketene Aminals

    Institute of Scientific and Technical Information of China (English)

    Tao PENG; Chu Yi YU; Zhi Tang HUANG

    2006-01-01

    An efficient solid-phase synthesis method for novel heterocyclic ketene aminals containing a hydroxyl group has been developed. The loading of the substrate on the resin through the hydroxyl group and the protection of the amine by the Schiff base were the key steps in the synthesis.

  11. Biscarbene palladium(II) complexes. Reactivity of saturated versus unsaturated N-heterocyclic carbenes

    NARCIS (Netherlands)

    C.F. Fu; C.C. Lee; Y.H. Liu; S.M. Peng; S. Warsink; C.J. Elsevier; J.T. Chen; S.T. Liu

    2010-01-01

    A series of designed palladium biscarbene complexes including saturated and unsaturated N-heterocyclic carbene (NHC) moieties have been prepared by the carbene transfer methods. All of these complexes have been characterized by 1H and 13C NMR spectroscopy as well as X-ray diffraction analysis. The r

  12. Mechanistic Investigation of the Ruthenium–N-Heterocyclic-Carbene-Catalyzed Amidation of Alcohols and Amines

    DEFF Research Database (Denmark)

    Makarov, Ilya; Fristrup, Peter; Madsen, Robert

    2012-01-01

    The mechanism of the ruthenium–N-heterocyclic-carbene-catalyzed formation of amides from alcohols and amines was investigated by experimental techniques (Hammett studies, kinetic isotope effects) and by a computational study by using dispersion-corrected density functional theory (DFT/ M06...

  13. Selective Removal of Nitrogen-Containing Heterocyclic Compounds from Transportation Diesel Fuels with Reactive Adsorbent

    Institute of Scientific and Technical Information of China (English)

    YANG Lei; WANG Shengqiang; WANG Ruicong; YU Hongbing

    2013-01-01

    This paper presents a new selective adsorbent to remove nitrogen-containing heterocyclic compounds from model and commercial transportation diesel fuels based on characteristic reaction designed to occur in the pores of substrate.This reactive adsorbent is composed of formaldehyde,phosphotungstic acid and Santa Barbara USA (SBA)-15.The experiment was based on assumed hydroxymethylation reaction of nitrogen-containing heterocyclic compounds with formaldehyde using phosphotungstic acid as catalyst in batch and fixed-bed systems.The nitrogen concentration in the model fuel was 237.33 ng·μl-1,carbazole and toluene were used as model nitrogen-containing heterocyclic compound and solvent,respectively.The effectiveness of reactive adsorbent for removal of nitrogen-containing heterocyclic compounds from commercial 0# diesel fuel containing 224.86 ng· μl-1 nitrogen was examined in a fixed-bed reactor at 70 ℃.The results showed that nitro1gen in the model fuel was very low and the nitrogen concentration in the commercial diesel reduced to 2.44 ng· μl-1.The demand for transportation fuel with ultra-low nitrogen is satisfied.

  14. A Photolabile Linker for the Solid-Phase Synthesis of Peptide Hydrazides and Heterocycles

    DEFF Research Database (Denmark)

    Qvortrup, Katrine; Komnatnyy, Vitaly V.; Nielsen, Thomas Eiland

    2014-01-01

    A photolabile hydrazine linker for the solid-phase synthesis of peptide hydrazides and hydrazine-derived heterocycles is presented. The developed protocols enable the efficient synthesis of structurally diverse peptide hydrazides derived from the standard amino adds, including those with side...

  15. Amide Synthesis from Alcohols and Amines Catalyzed by Ruthenium N-Heterocyclic Carbene Complexes

    DEFF Research Database (Denmark)

    Dam, Johan Hygum; Osztrovszky, Gyorgyi; Nordstrøm, Lars Ulrik Rubæk;

    2010-01-01

    The direct synthesis of amides from alcohols and amines is described with the simultaneous liberation of dihydrogen. The reaction does not require any stoichiometric additives or hydrogen acceptors and is catalyzed by ruthenium N-heterocyclic carbene complexes. Three different catalyst systems...

  16. N-Heterocyclic Carbene-Catalyzed Alcohol Acetylation: An Organic Experiment Using Organocatalysis

    Science.gov (United States)

    Morgan, John P.; Shrimp, Jonathan H.

    2014-01-01

    Undergraduate students in the teaching laboratory have successfully used N-heterocyclic carbenes (NHCs) as organocatalysts for the acetylation of primary alcohols, despite the high water sensitivity of uncomplexed ("free") NHCs. The free NHC readily reacted with chloroform, resulting in an air- and moisture-stable adduct that liberates…

  17. Mild and rational synthesis of palladium complexes comprising C(4)-bound N-heterocyclic carbenes

    OpenAIRE

    Kluser, Evelyne; Neels, Antonia; Albrecht, Martin

    2007-01-01

    Oxidative addition of pyridyl-functionalised 4-iodoimidazolium salts to palladium(0) gives catalytically active complexes in which the N-heterocyclic carbene is bound to the palladium(II) centre in a non-classical bonding mode via C(4).

  18. Transition Metal-Participated Synthesis and Utilization of N-containing Heterocycles: Exploring for Nitrogen Sources.

    Science.gov (United States)

    Gao, Mingchun; Xu, Bin

    2016-06-01

    This account aims to describe our recent efforts on the synthesis and utilization of N-containing heterocycles, where transition metals participate in the synthesis. A variety of nitrogen sources, including amines, amides, hydrazones, pyrimidines, isocyanides, and copper nitrate, have been disclosed for the synthesis of diverse bioactive and pharmacologically interesting N-containing heterocycles under the participation of transition metals. The well-known nitrogen sources, such as amines and amides, were used for the construction of indoles, isatins, and quinolones. Dihydrophthalazines, isoquinolines, indazoles, and pyrazoles were obtained from hydrazones, while various pyrimidine-containing heterocycles were afforded through regioselective C-H functionalizations using pyrimidine as the directing group. Recent research has focused on the chemistry of isocyanides to achieve several kinds of heterocyclic compounds with high efficiency under the catalysis of transition metals (Pd, Rh, Mn, Cu), through oxidative cyanation reactions, sequential isocyanide insertions into C-H, N-H, or O-H bonds, and tandem radical annulation. More recently, an efficient route to isoxazolines has been reported using copper nitrate as a novel nitrogen source. PMID:27230734

  19. Rapid and efficient synthesis of fused heterocyclic pyrimidines under ultrasonic irradiation.

    Science.gov (United States)

    Mosslemin, Mohammad Hossein; Nateghi, Mohammad Reza

    2010-01-01

    Some fused heterocyclic pyrimidines have been synthesized in high yields using ultrasound irradiation in a one-pot, three-component and efficient process by condensation reaction of barbituric acids, aldehydes and a series of enamines in water. Prominent among the advantages of this new method are operational simplicity, good yields in short reaction times and easy work-up procedures employed.

  20. N-Heterocyclic carbene functionalized goup 7-9 transition metal

    NARCIS (Netherlands)

    Aktas, H.; Slootweg, J.C.; Ehlers, A.W.; Lutz, M.; Spek, A.L.; Lammertsma, K.

    2009-01-01

    The N-heterocyclic carbene (NHC) functionalized phosphinidene complexes [(pCy)(IiPr2Me2)- RudPMes*] (4), [(pCy)(IiPr2Me2)OsdPMes*] (6), and [(Cp*)(IiPr2Me2)RhdPMes*] (7) were generated by a double-dehydrohalogenation-ligation sequence of the corresponding primary phosphine complexes with 3 equiv of