Quantitative analysis of microbicide concentrations in fluids, gels and tissues using confocal Raman spectroscopy.

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Oranat Chuchuen

Full Text Available Topical vaginal anti-HIV microbicides are an important focus in female-based strategies to prevent the sexual transmission of HIV. Understanding microbicide pharmacokinetics is essential to development, characterization and implementation of efficacious microbicide drug delivery formulations. Current methods to measure drug concentrations in tissue (e.g., LC-MS/MS, liquid chromatography coupled with tandem mass spectrometry are highly sensitive, but destructive and complex. This project explored the use of confocal Raman spectroscopy to detect microbicide drugs and to measure their local concentrations in fluids, drug delivery gels, and tissues. We evaluated three candidate microbicide drugs: tenofovir, Dapivirine and IQP-0528. Measurements were performed in freshly excised porcine buccal tissue specimens, gel vehicles and fluids using two Horiba Raman microscopes, one of which is confocal. Characteristic spectral peak calibrations for each drug were obtained using serial dilutions in the three matrices. These specific Raman bands demonstrated strong linear concentration dependences in the matrices and were characterized with respect to their unique vibrational signatures. At least one specific Raman feature was identified for each drug as a marker band for detection in tissue. Sensitivity of detection was evaluated in the three matrices. A specific peak was also identified for tenofovir diphosphate, the anti-HIV bioactive product of tenofovir after phosphorylation in host cells. Z-scans of drug concentrations vs. depth in excised tissue specimens, incubated under layers of tenofovir solution in a Transwell assay, showed decreasing concentration with depth from the surface into the tissue. Time-dependent concentration profiles were obtained from tissue samples incubated in the Transwell assay, for times ranging 30 minutes - 6 hours. Calibrations and measurements from tissue permeation studies for tenofovir showed good correlation with gold

Quantitative Analysis of Microbicide Concentrations in Fluids, Gels and Tissues Using Confocal Raman Spectroscopy

Science.gov (United States)

Chuchuen, Oranat; Henderson, Marcus H.; Sykes, Craig; Kim, Min Sung; Kashuba, Angela D. M.; Katz, David F.

2013-01-01

Topical vaginal anti-HIV microbicides are an important focus in female-based strategies to prevent the sexual transmission of HIV. Understanding microbicide pharmacokinetics is essential to development, characterization and implementation of efficacious microbicide drug delivery formulations. Current methods to measure drug concentrations in tissue (e.g., LC-MS/MS, liquid chromatography coupled with tandem mass spectrometry) are highly sensitive, but destructive and complex. This project explored the use of confocal Raman spectroscopy to detect microbicide drugs and to measure their local concentrations in fluids, drug delivery gels, and tissues. We evaluated three candidate microbicide drugs: tenofovir, Dapivirine and IQP-0528. Measurements were performed in freshly excised porcine buccal tissue specimens, gel vehicles and fluids using two Horiba Raman microscopes, one of which is confocal. Characteristic spectral peak calibrations for each drug were obtained using serial dilutions in the three matrices. These specific Raman bands demonstrated strong linear concentration dependences in the matrices and were characterized with respect to their unique vibrational signatures. At least one specific Raman feature was identified for each drug as a marker band for detection in tissue. Sensitivity of detection was evaluated in the three matrices. A specific peak was also identified for tenofovir diphosphate, the anti-HIV bioactive product of tenofovir after phosphorylation in host cells. Z-scans of drug concentrations vs. depth in excised tissue specimens, incubated under layers of tenofovir solution in a Transwell assay, showed decreasing concentration with depth from the surface into the tissue. Time-dependent concentration profiles were obtained from tissue samples incubated in the Transwell assay, for times ranging 30 minutes - 6 hours. Calibrations and measurements from tissue permeation studies for tenofovir showed good correlation with gold standard LC-MS/MS data

Microbicides in India-present and future

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Nath A

2009-01-01

Full Text Available India continues to wage a battle against the human immunodeficiency virus (HIV/acquired immune deficiency syndrome (AIDS epidemic. Despite an array of preventive and control efforts directed against the disease, it continues to finds its way from the high risk groups to the general population. Women are more vulnerable to HIV/AIDS because of biological as well as socio-cultural factors. Microbicides appear to provide an attractive option as a means of protection to be used by women. At present, microbicide trials are in study phases I and II in India. The development of an ideal microbicide candidate which would be effective and confirms to user satisfaction poses a major challenge to researchers.

Nanomedicine in the development of anti-HIV microbicides.

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das Neves, José; Nunes, Rute; Rodrigues, Francisca; Sarmento, Bruno

2016-08-01

Prevention plays an invaluable role in the fight against HIV/AIDS. The use of microbicides is considered an interesting potential approach for topical pre-exposure prophylaxis of HIV sexual transmission. The prospects of having an effective product available are expected to be fulfilled in the near future as driven by recent and forthcoming results of clinical trials. Different dosage forms and delivery strategies have been proposed and tested for multiple microbicide drug candidates presently at different stages of the development pipeline. One particularly interesting approach comprises the application of nanomedicine principles to the development of novel anti-HIV microbicides, but its implications to efficacy and safety are not yet fully understood. Nanotechnology-based systems, either presenting inherent anti-HIV activity or acting as drug nanocarriers, may significantly influence features such as drug solubility, stability of active payloads, drug release, interactions between active moieties and virus/cells, intracellular drug delivery, drug targeting, safety, antiviral activity, mucoadhesive behavior, drug distribution and tissue penetration, and pharmacokinetics. The present manuscript provides a comprehensive and holistic overview of these topics as relevant to the development of vaginal and rectal microbicides. In particular, recent advances pertaining inherently active microbicide nanosystems and microbicide drug nanocarriers are discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of undecylenic acid as a topical microbicide against genital herpes infection in mice and guinea pigs.

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Bourne, N; Ireland, J; Stanberry, L R; Bernstein, D I

1999-01-01

There is increasing interest in the use of topical microbicides to help prevent the spread of sexually transmitted diseases (STD). Undecylenic acid (UA), a monosaturated fatty acid, is the active ingredient in a number of over-the-counter (OTC) antifungal spray powders, that also exhibits in vitro antibacterial and antiviral activity, including herpes simplex virus (HSV) activity. We, therefore, evaluated UA as a topical microbicide against genital HSV infection using the murine and guinea pig models of genital herpes. Mice were administered a 20% solution of UA in polyethylene glycol (PEG) vehicle, vehicle alone or phosphate buffered saline (PBS) intravaginally immediately prior to vaginal challenge with HSV-2. Pre-treatment with UA decreased the number of mice that became infected (P < 0.001 vs. PBS or vehicle control), developed symptoms (P <0.001) or died (P <0.001). However, when treatment was extended to either 5 min prior to or after viral inoculation, protection was lost. Similar findings were found using the guinea pig model, where UA treatment completely prevented HSV-2 vaginal infection when given immediately prior to HSV-2 inoculation (P<0.001 vs. PBS or vehicle control). Thus, UA, an approved OTC medication, provided significant protection against HSV disease and infection only when applied immediately before viral inoculation, indicating that better formulations were needed to extend the duration of protection.

Microbicides and HIV prevention | Sibeko | Obstetrics and ...

African Journals Online (AJOL)

Microbicide agents come in different preparations and/or formulations. The first generation microbicides are gels and creams; whereas subsequent generations include vaginal rings, films, sponges, gels with barrier devices and suppositories, and work by altering the environment of the genital tract to make it unsuitable for

Twice-daily application of HIV microbicides alter the vaginal microbiota.

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Ravel, Jacques; Gajer, Pawel; Fu, Li; Mauck, Christine K; Koenig, Sara S K; Sakamoto, Joyce; Motsinger-Reif, Alison A; Doncel, Gustavo F; Zeichner, Steven L

2012-12-18

Vaginal HIV microbicides offer great promise in preventing HIV transmission, but failures of phase 3 clinical trials, in which microbicide-treated subjects had an increased risk of HIV transmission, raised concerns about endpoints used to evaluate microbicide safety. A possible explanation for the increased transmission risk is that the agents shifted the vaginal bacterial community, resulting in loss of natural protection and enhanced HIV transmission susceptibility. We characterized vaginal microbiota, using pyrosequencing of bar-coded 16S rRNA gene fragments, in samples from 35 healthy, sexually abstinent female volunteer subjects (ages 18 to 50 years) with regular menses in a repeat phase 1 study of twice-daily application over 13.5 days of 1 of 3 gel products: a hydroxyethylcellulose (HEC)-based "universal" placebo (10 subjects), 6% cellulose sulfate (CS; 13 subjects), and 4% nonoxynol-9 (N-9; 12 subjects). We used mixed effects models inferred using Bayesian Markov chain Monte Carlo methods, which showed that treatment with active agents shifted the microbiota toward a community type lacking significant numbers of Lactobacillus spp. and dominated by strict anaerobes. This state of the vaginal microbiota was associated with a low or intermediate Nugent score and was not identical to bacterial vaginosis, an HIV transmission risk factor. The placebo arm contained a higher proportion of communities dominated by Lactobacillus spp., particularly L. crispatus, throughout treatment. The data suggest that molecular evaluation of microbicide effects on vaginal microbiota may be a critical endpoint that should be incorporated in early clinical assessment of microbicide candidates. Despite large prevention efforts, HIV transmission and acquisition rates remain unacceptably high. In developing countries, transmission mainly occurs through heterosexual intercourse, where women are significantly more vulnerable to infection than men. Vaginal microbicides are considered to

Mucosal safety of PHI-443 and stampidine as a combination microbicide to prevent genital transmission of HIV-1.

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D'Cruz, Osmond J; Uckun, Fatih M

2007-10-01

To investigate the in vitro and in vivo mucosal safety of a nonnucleoside reverse transcriptase (RT) inhibitor (PHI-443) and a nucleoside analogue RT inhibitor (stampidine)-based anti-HIV microbicide either alone or in combination. In vitro and in vivo studies using three-dimensional vaginal epithelia integrating Langerhans cells and 16 New Zealand White rabbits, respectively. Research laboratory. Rabbits in groups of four were exposed intravaginally to a gel with and without 1% PHI-443, 1% stampidine, or 1% PHI-443 plus 1% stampidine for 14 days. Cytokine/chemokine release by three-dimensional co-cultures in the presence and absence of PHI-443 or stampidine. Histologic scoring of vaginal tissue for mucosal toxicity at 24 hours after dosing. Simultaneous evaluation of levels of 10 cytokines (granulocyte-macrophage colony-stimulating factor, interleukin-1 alpha, interleukin-13, macrophage inflammatory protein-1 beta, granulocyte colony-stimulating factor, interleukin-18, tumor necrosis factor-alpha, interleukin-6, interleukin-1 beta, and interferon-gamma) and 6 chemokines (epithelial neutrophil-activating peptide-78, interleukin-8, monocyte/macrophage chemoattractant protein-1, macrophage inflammatory protein-3 alpha, interferon-inducible protein-10, and regulated upon activation of normal T-cell expressed and secreted) in culture media by a multiplexed chemiluminescence-based immunoassay. In the rabbit model, repeated intravaginal administration of PHI-443 plus stampidine via a gel formulation at concentrations nearly 2,000 and 10,000 times higher than their respective in vitro anti-HIV IC(50) values did not result in vaginal irritation. The levels of proinflammatory cytokines/chemokines secreted by multilayered human genital epithelia integrating Langerhans cells were unaffected by prolonged exposure to PHI-443 or stampidine. The combination of PHI-443 and stampidine was noncytotoxic to vaginal epithelial cells, nonirritating to vaginal mucosa, and did not induce

Young women's contraceptive microbicide preferences: associations with contraceptive behavior and sexual relationship characteristics.

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Best, Candace; Tanner, Amanda E; Hensel, Devon J; Fortenberry, J Dennis; Zimet, Gregory D

2014-03-01

In time, microbicides may provide women with dual prevention against pregnancy and STDs. Although several microbicide dimensions have been evaluated, little is known about women's preferences for contraceptive microbicides and correlates of these preferences. Acceptability of a hypothetical contraceptive microbicide cream or jelly was examined among a -clinic-based sample of 266 women in Indianapolis from 2004 (when participants were aged 14-22) to 2008. Group conjoint analyses and individual conjoint analyses were used to compare preferences with respect to four microbicide -dimensions: contraceptive ability, efficacy in relation to condoms, timing of use and texture. Pearson's product moment correlations were used to examine the relationship between preferences for a contraceptive microbicide and selected characteristics of the women. Overall, the top-rated microbicide dimensions were efficacy in relation to that of condoms and contraceptive ability (importance scores, 40.0 and 35.4 out of 100.0, respectively). When all dimension levels were compared, contraceptive ability was the most strongly preferred (part-worth utility score, 8.9), and lower efficacy than that of -condoms was the least strongly preferred (-11.9). Preference for contraceptive microbicides was positively -associated with current contraceptive use, sexual agency, partner communication, commitment to avoiding pregnancy and -perceived partner agreement about avoiding pregnancy (coefficients, 0.07-0.18). It was negatively associated with current or past nonuse of contraceptives, seeking pregnancy and perceived partner agreement about seeking -pregnancy (-0.08 to -0.14). Microbicides with dual prevention properties may be attractive to young women. Microbicide development and subsequent clinical trials should incorporate contraceptive microbicides. Copyright © 2013 by the Guttmacher Institute.

In vitro resistance profile of the candidate HIV-1 microbicide drug dapivirine.

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Schader, Susan M; Oliveira, Maureen; Ibanescu, Ruxandra-Ilinca; Moisi, Daniela; Colby-Germinario, Susan P; Wainberg, Mark A

2012-02-01

Antiretroviral-based microbicides may offer a means to reduce the sexual transmission of HIV-1. Suboptimal use of a microbicide may, however, lead to the development of drug resistance in users that are already, or become, infected with HIV-1. In such cases, the efficacy of treatments may be compromised since the same (or similar) antiretrovirals used in treatments are being developed as microbicides. To help predict which drug resistance mutations may develop in the context of suboptimal use, HIV-1 primary isolates of different subtypes and different baseline resistance profiles were used to infect primary cells in vitro in the presence of increasing suboptimal concentrations of the two candidate microbicide antiretrovirals dapivirine (DAP) and tenofovir (TFV) alone or in combination. Infections were ongoing for 25 weeks, after which reverse transcriptase genotypes were determined and scrutinized for the presence of any clinically recognized reverse transcriptase drug resistance mutations. Results indicated that suboptimal concentrations of DAP alone facilitated the emergence of common nonnucleoside reverse transcriptase inhibitor resistance mutations, while suboptimal concentrations of DAP plus TFV gave rise to fewer mutations. Suboptimal concentrations of TFV alone did not frequently result in the development of resistance mutations. Sensitivity evaluations for stavudine (d4T), nevirapine (NVP), and lamivudine (3TC) revealed that the selection of resistance as a consequence of suboptimal concentrations of DAP may compromise the potential for NVP to be used in treatment, a finding of potential relevance in developing countries.

Rational design of HIV vaccines and microbicides: report of the EUROPRISE annual conference 2011.

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Ruffin, Nicolas; Borggren, Marie; Euler, Zelda; Fiorino, Fabio; Grupping, Katrijn; Hallengärd, David; Javed, Aneele; Mendonca, Kevin; Pollard, Charlotte; Reinhart, David; Saba, Elisa; Sheik-Khalil, Enas; Sköld, Annette; Ziglio, Serena; Scarlatti, Gabriella; Gotch, Frances; Wahren, Britta; Shattock, Robin J

2012-07-11

Europrise is a Network of Excellence supported by the European Commission within the 6th Framework programme from 2007 to 2012. The Network has involved over 50 institutions from 13 European countries together with 3 industrial partners and 6 African countries. The Network encompasses an integrated program of research, training, dissemination and advocacy within the field of HIV vaccines and microbicides. A central and timely theme of the Network is the development of the unique concept of co-usage of vaccines and microbicides. Training of PhD students has been a major task, and some of these post-graduate students have here summarized novel ideas emanating from presentations at the last annual Europrise meeting in Prague. The latest data and ideas concerning HIV vaccine and microbicide studies are included in this review; these studies are so recent that the majority have yet to be published. Data were presented and discussed concerning novel immunisation strategies; microbicides and PrEP (alone and in combination with vaccines); mucosal transmission of HIV/SIV; mucosal vaccination; novel adjuvants; neutralizing antibodies; innate immune responses; HIV/SIV pathogenesis and disease progression; new methods and reagents. These - necessarily overlapping topics - are comprehensively summarised by the Europrise students in the context of other recent exciting data.

Rational design of HIV vaccines and microbicides: report of the EUROPRISE annual conference 2011

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Ruffin Nicolas

2012-07-01

Full Text Available Abstract Europrise is a Network of Excellence supported by the European Commission within the 6th Framework programme from 2007 to 2012. The Network has involved over 50 institutions from 13 European countries together with 3 industrial partners and 6 African countries. The Network encompasses an integrated program of research, training, dissemination and advocacy within the field of HIV vaccines and microbicides. A central and timely theme of the Network is the development of the unique concept of co-usage of vaccines and microbicides. Training of PhD students has been a major task, and some of these post-graduate students have here summarized novel ideas emanating from presentations at the last annual Europrise meeting in Prague. The latest data and ideas concerning HIV vaccine and microbicide studies are included in this review; these studies are so recent that the majority have yet to be published. Data were presented and discussed concerning novel immunisation strategies; microbicides and PrEP (alone and in combination with vaccines; mucosal transmission of HIV/SIV; mucosal vaccination; novel adjuvants; neutralizing antibodies; innate immune responses; HIV/SIV pathogenesis and disease progression; new methods and reagents. These – necessarily overlapping topics - are comprehensively summarised by the Europrise students in the context of other recent exciting data.

Hypothetical Rectal Microbicide Acceptability and Factors Influencing It among Men Who Have Sex with Men in Tianjin, China.

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Guohong Zhang

Full Text Available To measure potential acceptability of rectal microbicides and to explore factors likely to affect their acceptability among men who have sex with men (MSM.Cross-sectional and retrospective surveys were conducted in this study. A questionnaire and a scale were used to measure the acceptability score for physical and functional characteristics of hypothetical rectal microbicides. We also evaluated the involvement of other factors such as sexual behaviors, social context, etc.MSMs we interviewed showed a high acceptability to rectal microbicides, indicated by the mean acceptability score of 2.92 (SD, 0.54, scale of 1-4. The results also suggested that microbicides were preferred in a cream form that can moisten and lubricate the rectum, prevent HIV infection and go unnoticed by their partners. Multivariate analysis showed that the microbicides acceptability varied significantly by education level (β = 0.135; P = 0.028, having casual partners (β = 0.174; P = 0.007, frequency of lubricant use (β = 0.134; P = 0.031, history of HIV test (β = 0.129; P = 0.036, willingness to use lubricant (β = 0.126; P = 0.045, locus of control by partners regarding STI infection (β = 0.168; P = 0.009.A positive response to rectal microbicides among MSMs was found in our study, suggesting that rectal microbicides might have a potential market in MSMs and they might play an important role in HIV/STIs prevention as a supplement. Further studies may be considered to combine the acceptability study with clinical research together to understand the true feelings of MSMs when they use the products.

Perceptions of acceptability and utility of microbicides in Ghana ...

African Journals Online (AJOL)

In addition, gendered negotiation power and the implications of covert use need to be addressed in microbicide education and social marketing. Les microbicides vaginaux, une substance qui pourrait largement réduire les infections sexuellement transmises (IST) et le VIH inclus, font actuellement parti des essais cliniques.

Whither or wither microbicides?

NARCIS (Netherlands)

Grant, Robert M.; Hamer, Dean; Hope, Thomas; Johnston, Rowena; Lange, Joep; Lederman, Michael M.; Lieberman, Judy; Miller, Christopher J.; Moore, John P.; Mosier, Donald E.; Richman, Douglas D.; Schooley, Robert T.; Springer, Marty S.; Veazey, Ronald S.; Wainberg, Mark A.

2008-01-01

After disappointing results from all efficacy trials conducted to date, the field of microbicides research now faces substantial challenges. Poor coordination among interested parties and the choice of nonvalidated scientific targets for phase III studies have hampered progress and created mistrust

Perceptions of vaginal microbicides as an HIV prevention method among health care providers in KwaZulu-Natal, South Africa

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Mantell Joanne E

2007-03-01

Full Text Available Abstract Background The promise of microbicides as an HIV prevention method will not be realized if not supported by health care providers. They are the primary source of sexual health information for potential users, in both the public and private health sectors. Therefore, the aim of this study was to determine perceptions of vaginal microbicides as a potential HIV prevention method among health care providers in Durban and Hlabisa, South Africa, using a combination of quantitative and qualitative methods. Results During 2004, semi structured interviews with 149 health care providers were conducted. Fifty seven percent of hospital managers, 40% of pharmacists and 35% of nurses possessed some basic knowledge of microbicides, such as the product being used intra-vaginally before sex to prevent HIV infection. The majority of them were positive about microbicides and were willing to counsel users regarding potential use. Providers from both public and private sectors felt that an effective microbicide should be available to all people, regardless of HIV status. Providers felt that the product should be accessed over-the-counter in pharmacies and in retail stores. They also felt a need for potential microbicides to be available free of charge, and packaged with clear instructions. The media was seen by health care providers as being an effective strategy for promoting microbicides. Conclusion Overall, health care providers were very positive about the possible introduction of an effective microbicide for HIV prevention. The findings generated by this study illustrated the need for training health care providers prior to making the product accessible, as well as the importance of addressing the potential barriers to use of the product by women. These are important concerns in the health care community, and this study also served to educate them for the day when research becomes reality.

HIV enhancing activity of semen impairs the antiviral efficacy of microbicides

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Zirafi, Onofrio; Kim, Kyeong-Ae; Roan, Nadia R.; Kluge, Silvia F.; Müller, Janis A.; Jiang, Shibo; Mayer, Benjamin; Greene, Warner C.; Kirchhoff, Frank; Münch, Jan

2015-01-01

Topically applied microbicides potently inhibit HIV in vitro but have largely failed to exert protective effects in clinical trials. One possible reason for this discrepancy is that the preclinical testing of microbicides does not faithfully reflect the conditions of HIV sexual transmission. Here, we report that candidate microbicides that target HIV components show greatly reduced antiviral efficacy in the presence of semen, the main vector for HIV transmission. This diminished antiviral activity was dependent on the ability of amyloid fibrils in semen to enhance the infectivity of HIV. Thus, the anti-HIV efficacy of microbicides determined in the absence of semen greatly underestimated the drug concentrations needed to block semen-exposed virus. One notable exception was Maraviroc. This HIV entry inhibitor targets the host cell CCR5 coreceptor and was highly active against both untreated and semen-exposed HIV. These data help explain why microbicides have failed to protect against HIV in clinical trials and suggest that antiviral compounds targeting host factors hold promise for further development. These findings also suggest that the in vitro efficacy of candidate microbicides should be determined in the presence of semen to identify the best candidates for the prevention of HIV sexual transmission. PMID:25391483

The use of supersaturation for the vaginal application of microbicides: a case study with dapivirine.

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Grammen, Carolien; Plum, Jakob; Van Den Brande, Jeroen; Darville, Nicolas; Augustyns, Koen; Augustijns, Patrick; Brouwers, Joachim

2014-11-01

In this study, we investigated the potential of supersaturation for the formulation of the poorly water-soluble microbicide dapivirine (DPV) in an aqueous vaginal gel in order to enhance its vaginal tissue uptake. Different excipients such as hydroxypropylmethylcellulose, polyethylene glycol 1000, and cyclodextrins were evaluated for their ability to inhibit precipitation of supersaturated DPV in the formulation vehicle as such as well as in biorelevant media. In vitro permeation assessment across HEC-1A cell layers demonstrated an enhanced DPV flux from supersaturated gels compared with suspension gels. The best performing supersaturated gel containing 500 μM DPV (supersaturation degree of 4) in the presence of sulfobutyl ether-beta-cyclodextrin (2.5%) appeared to be stable for at least 3 months. In addition, the gel generated a significant increase in vaginal drug uptake in rabbits as compared with suspension gels. We conclude that supersaturation is a possible strategy to enhance the vaginal concentration of hydrophobic microbicides, thereby increasing permeation into the vaginal submucosa. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

Vaginal rings for delivery of HIV microbicides.

Science.gov (United States)

Malcolm, R Karl; Fetherston, Susan M; McCoy, Clare F; Boyd, Peter; Major, Ian

2012-01-01

Following the successful development of long-acting steroid-releasing vaginal ring devices for the treatment of menopausal symptoms and contraception, there is now considerable interest in applying similar devices to the controlled release of microbicides against HIV. In this review article, the vaginal ring concept is first considered within the wider context of the early advances in controlled-release technology, before describing the various types of ring device available today. The remainder of the article highlights the key developments in HIV microbicide-releasing vaginal rings, with a particular focus on the dapivirine ring that is presently in late-stage clinical testing.

The future of HIV prevention: prospects for an effective anti-HIV microbicide.

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Nuttall, Jeremy; Romano, Joseph; Douville, Karen; Galbreath, Caroline; Nel, Annaléne; Heyward, William; Mitchnick, Mark; Walker, Saul; Rosenberg, Zeda

2007-03-01

Topical microbicides are self-administered products for prevention of HIV transmission, and they present one of the most promising strategies for combating the HIV-AIDS epidemic. The development of microbicides is a long and complicated process, with many hurdles that are unique to this class of product, including challenges in product design, in the conduct and design of clinical trials, and in obtaining licensure of a new class of products intended for use almost exclusively in developing countries. Once they have been registered, there are additional challenges to the marketing and distribution of microbicides. An overview of the types of microbicide currently in development, and a summary of the issues and the approaches being taken to address them, are provided.

Microbicide research in developing countries: have we given the ethical concerns due consideration?

Science.gov (United States)

Moodley, Keymanthri

2007-09-19

HIV prevention research has been fraught with ethical concerns since its inception. These concerns were highlighted during HIV vaccine research and have been elaborated in microbicide research. A host of unique ethical concerns pervade the microbicide research process from trial design to post-trial microbicide availability. Given the urgency of research and development in the face of the devastating HIV pandemic, these ethical concerns represent an enormous challenge for investigators, sponsors and Research Ethics Committees (RECs) both locally and internationally. Ethical concerns relating to safety in microbicide research are a major international concern. However, in the urgency to develop a medically efficacious microbicide, some of these concerns may not have been anticipated. In the risk-benefit assessment of research protocols, both medical and psycho-social risk must be considered. In this paper four main areas that have a potential for medical and/or psycho-social harm are examined. Male partner involvement is controversial in the setting of covert use of microbicides. However, given the long-term exposure of men to experimental products, this may be methodologically, ethically and legally important. Covert use of microbicides may impact negatively on relationship dynamics leading to psychosocial harm to varying extents. The unexpectedly high rates of pregnancy during clinical trials raise important methodological and ethical concerns. Enrollment of adolescents without parental consent generates ethical and legal concerns that must be carefully considered by RECs and trial sites. Finally, paradoxical outcomes in recent trials internationally have advanced the debate on the nature of informed consent and responsibility of researchers to participants who become HIV positive during or after trials. Phase 3 microbicide trials are an undisputed research and ethical priority in developing countries. However, such trials must be conducted with attention to both

Clinical use of vaginal or rectally applied microbicides in patients suffering from HIV/AIDS

Directory of Open Access Journals (Sweden)

Gupta SK

2013-10-01

Full Text Available Satish Kumar Gupta, Nutan Reproductive Cell Biology Laboratory, National Institute of Immunology, New Delhi, India Abstract: Microbicides, primarily used as topical pre-exposure prophylaxis, have been proposed to prevent sexual transmission of HIV. This review covers the trends and challenges in the development of safe and effective microbicides to prevent sexual transmission of HIV. Initial phases of microbicide development used such surfactants as nonoxynol-9 (N-9, C13G, and sodium lauryl sulfate, aiming to inactivate the virus. Clinical trials of microbicides based on N-9 and C31G failed to inhibit sexual transmission of HIV. On the contrary, N-9 enhanced susceptibility to sexual transmission of HIV-1. Subsequently, microbicides based on polyanions and a variety of other compounds that inhibit the binding, fusion, or entry of virus to the host cells were evaluated for their efficacy in different clinical setups. Most of these trials failed to show either safety or efficacy for prevention of HIV transmission. The next phase of microbicide development involved antiretroviral drugs. Microbicide in the form of 1% tenofovir vaginal gel when tested in a Phase IIb trial (CAPRISA 004 in a coitally dependent manner revealed that tenofovir gel users were 39% less likely to become HIV-infected compared to placebo control. However, in another trial (VOICE MTN 003, tenofovir gel used once daily in a coitally independent mode failed to show any efficacy to prevent HIV infection. Tenofovir gel is currently in a Phase III safety and efficacy trial in South Africa (FACTS 001 employing a coitally dependent dosing regimen. Further, long-acting microbicide-delivery systems (vaginal ring for slow release of such antiretroviral drugs as dapivirine are also undergoing clinical trials. Discovering new markers as correlates of protective efficacy, novel long-acting delivery systems with improved adherence in the use of microbicides, discovering new compounds

Vaginal microbicides: how do you kick-start a global market?

Science.gov (United States)

1996-10-01

Efforts are underway to develop vaginal microbicides capable of protecting women against HIV and sexually transmitted disease. It was reported at the recent Vancouver international AIDS conference that 20 such products are in the preclinical stage, 13 in the early clinical stage, and two at the late clinical stage. The private sector, however, is not convinced of the commercial viability of vaginal microbicides, especially in developing countries. Johnson & Johnson has estimated there to be a US$40 million world market for vaginal microbicides, too small to garner the interest and involvement of the major research and development-based multinational pharmaceutical companies. The European Commission has therefore contracted Hillmark, a UK consultancy, to assess the market for such products in Cote d'Ivoire, Egypt, Kenya, South Africa, France, Poland, India, Thailand, Philippines, Brazil, and Venezuela. Corporate interest may be sparked by a convincing assessment of a higher market potential. Also at the Vancouver conference, the US Secretary of Health announced grant funding of US$100 million for research into microbicides.

Clinical use of vaginal or rectally applied microbicides in patients suffering from HIV/AIDS.

Science.gov (United States)

Gupta, Satish Kumar; Nutan

2013-10-22

Microbicides, primarily used as topical pre-exposure prophylaxis, have been proposed to prevent sexual transmission of HIV. This review covers the trends and challenges in the development of safe and effective microbicides to prevent sexual transmission of HIV Initial phases of microbicide development used such surfactants as nonoxynol-9 (N-9), C13G, and sodium lauryl sulfate, aiming to inactivate the virus. Clinical trials of microbicides based on N-9 and C31G failed to inhibit sexual transmission of HIV. On the contrary, N-9 enhanced susceptibility to sexual transmission of HIV-1. Subsequently, microbicides based on polyanions and a variety of other compounds that inhibit the binding, fusion, or entry of virus to the host cells were evaluated for their efficacy in different clinical setups. Most of these trials failed to show either safety or efficacy for prevention of HIV transmission. The next phase of microbicide development involved antiretroviral drugs. Microbicide in the form of 1% tenofovir vaginal gel when tested in a Phase IIb trial (CAPRISA 004) in a coitally dependent manner revealed that tenofovir gel users were 39% less likely to become HIV-infected compared to placebo control. However, in another trial (VOICE MTN 003), tenofovir gel used once daily in a coitally independent mode failed to show any efficacy to prevent HIV infection. Tenofovir gel is currently in a Phase III safety and efficacy trial in South Africa (FACTS 001) employing a coitally dependent dosing regimen. Further, long-acting microbicide-delivery systems (vaginal ring) for slow release of such antiretroviral drugs as dapivirine are also undergoing clinical trials. Discovering new markers as correlates of protective efficacy, novel long-acting delivery systems with improved adherence in the use of microbicides, discovering new compounds effective against a broad spectrum of HIV strains, developing multipurpose technologies incorporating additional features of efficacy against other

Integrated Vehicle Thermal Management - Combining Fluid Loops in Electric Drive Vehicles (Presentation)

Energy Technology Data Exchange (ETDEWEB)

Rugh, J. P.

2013-07-01

Plug-in hybrid electric vehicles and electric vehicles have increased vehicle thermal management complexity, using separate coolant loop for advanced power electronics and electric motors. Additional thermal components result in higher costs. Multiple cooling loops lead to reduced range due to increased weight. Energy is required to meet thermal requirements. This presentation for the 2013 Annual Merit Review discusses integrated vehicle thermal management by combining fluid loops in electric drive vehicles.

Potential Use of Antimicrobial Peptides as Vaginal Spermicides/Microbicides

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Nongnuj Tanphaichitr

2016-03-01

Full Text Available The concurrent increases in global population and sexually transmitted infection (STI demand a search for agents with dual spermicidal and microbicidal properties for topical vaginal application. Previous attempts to develop the surfactant spermicide, nonoxynol-9 (N-9, into a vaginal microbicide were unsuccessful largely due to its inefficiency to kill microbes. Furthermore, N-9 causes damage to the vaginal epithelium, thus accelerating microbes to enter the women’s body. For this reason, antimicrobial peptides (AMPs, naturally secreted by all forms of life as part of innate immunity, deserve evaluation for their potential spermicidal effects. To date, twelve spermicidal AMPs have been described including LL-37, magainin 2 and nisin A. Human cathelicidin LL-37 is the most promising spermicidal AMP to be further developed for vaginal use for the following reasons. First, it is a human AMP naturally produced in the vagina after intercourse. Second, LL-37 exerts microbicidal effects to numerous microbes including those that cause STI. Third, its cytotoxicity is selective to sperm and not to the female reproductive tract. Furthermore, the spermicidal effects of LL-37 have been demonstrated in vivo in mice. Therefore, the availability of LL-37 as a vaginal spermicide/microbicide will empower women for self-protection against unwanted pregnancies and STI.

Learning from the private sector: towards a keener understanding of the end-user for microbicide introduction planning.

Science.gov (United States)

Lin, Amy H; Breger, Tiffany L; Barnhart, Matthew; Kim, Ann; Vangsgaard, Charlotte; Harris, Emily

2014-01-01

that enhances product usage. The introduction of microbicide products presents an ideal opportunity to draw on the insights from user-centred private sector companies' approaches, which can complement other methods that have been more commonly utilized in microbicide research to date. As microbicides move from clinical trials to real-world implementation, there will be more opportunities to combine a variety of approaches to understand end-users, which can lead to a more effective product launch and ultimately greater impact on preventing HIV infections.

Plant made anti-HIV microbicides: a field of opportunity

CSIR Research Space (South Africa)

Lotter-Stark, HCT

2012-11-01

Full Text Available -HIV microbicides- a field of opportunity Hester C.T. Lotter-Stark1*, Edward P. Rybicki2 and Rachel K. Chikwamba1 1 Council for Scientific and Industrial Research (CSIR), Biosciences, Pretoria, South Africa. 2 Institute of Infectious Disease and Molecular... efficacious in in vitro and in vivo protection studies. For the purpose of development and access by the relevant 2 population groups, it is crucial that these microbicides be produced at low cost. For the promising protein and peptide candidate...

Neutrophil Leukocyte: Combustive Microbicidal Action and Chemiluminescence

Directory of Open Access Journals (Sweden)

Robert C. Allen

2015-01-01

Full Text Available Neutrophil leukocytes protect against a varied and complex array of microbes by providing microbicidal action that is simple, potent, and focused. Neutrophils provide such action via redox reactions that change the frontier orbitals of oxygen (O2 facilitating combustion. The spin conservation rules define the symmetry barrier that prevents direct reaction of diradical O2 with nonradical molecules, explaining why combustion is not spontaneous. In burning, the spin barrier is overcome when energy causes homolytic bond cleavage producing radicals capable of reacting with diradical O2 to yield oxygenated radical products that further participate in reactive propagation. Neutrophil mediated combustion is by a different pathway. Changing the spin quantum state of O2 removes the symmetry restriction to reaction. Electronically excited singlet molecular oxygen (O2*1 is a potent electrophilic reactant with a finite lifetime that restricts its radius of reactivity and focuses combustive action on the target microbe. The resulting exergonic dioxygenation reactions produce electronically excited carbonyls that relax by light emission, that is, chemiluminescence. This overview of neutrophil combustive microbicidal action takes the perspectives of spin conservation and bosonic-fermionic frontier orbital considerations. The necessary principles of particle physics and quantum mechanics are developed and integrated into a fundamental explanation of neutrophil microbicidal metabolism.

Microbicidal Effects of Stored Aqueous Ozone Solution Generated by Nano-bubble Technology.

Science.gov (United States)

Seki, Mineaki; Ishikawa, Tatsuya; Terada, Hiroshi; Nashimoto, Masayuki

2017-01-01

Clinically used disinfectants are often irritating and cause skin problems. Ozone water is unique among disinfectants. It does not damage skin cells and readily decomposes to oxygen without generating harmful residues. On the other hand, it rapidly loses its sanitizing activity. Recently developed nano-bubble ozone water (NBOW) can keep its sanitizing activity much longer. This study aimed to examine the microbicidal effects of NBOW after long-term storage. The concentration of ozone in NBOW was examined by measuring the NBOW redox potential. Microbicidal activity was evaluated by colony formation assays, after incubating bacteria with NBOW for set time periods. NBOW lost its microbicidal activity after 1 year of storage at 4°C. Stocked frozen, NBOW retained appreciable microbicidal activity after 1 year of storage. Mycobacterium smegmatis, one of the most disinfectant-resistant bacteria, was killed within 15 min. NBOW was resistant to freeze-thawing. NBOW that had been stored frozen possessed sufficient microbicidal activity to kill bacteria even after 1 year of storage. Moreover, it was shown that NBOW is freeze-thaw resistant. NBOW possesses desirable features rendering it an attractive alternative disinfectant. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Intravaginal rings as delivery systems for microbicides and multipurpose prevention technologies

Directory of Open Access Journals (Sweden)

Thurman AR

2013-10-01

Full Text Available Andrea Ries Thurman, Meredith R Clark, Jennifer Hurlburt, Gustavo F Doncel CONRAD, Department of Obstetrics and Gynecology, Eastern Virginia Medical School, Norfolk, VA, USA Abstract: There is a renewed interest in delivering pharmaceutical products via intravaginal rings (IVRs. IVRs are flexible torus-shaped drug delivery systems that can be easily inserted and removed by the woman and that provide both sustained and controlled drug release, lasting for several weeks to several months. In terms of women's health care products, it has been established that IVRs effectively deliver contraceptive steroids and steroids for the treatment of postmenopausal vaginal atrophy. A novel application for IVRs is the delivery of antiretroviral drugs for the prevention of human immunodeficiency virus (HIV genital infection. Microbicides are antiviral drugs delivered topically for HIV prevention. Recent reviews of microbicide IVRs have focused on technologies in development and optimizing ring design. IVRs have several advantages, including the ability to deliver sustained drug doses for long periods of time while bypassing first pass metabolism in the gut. IVRs are discreet, woman-controlled, and do not require a trained provider for placement or fitting. Previous data support that women and their male sexual partners find IVRs highly acceptable. Multipurpose prevention technology (MPT products provide protection against unintended/mistimed pregnancy and reproductive tract infections, including HIV. Several MPT IVRs are currently in development. Early clinical testing of new microbicide and MPT IVRs will require a focus on safety, pharmacokinetics and pharmacodynamics. Specifically, IVRs will have to deliver tissue concentrations of drugs that are pharmacodynamically active, do not cause mucosal alterations or inflammation, and do not change the resident microbiota. The emergence of resistance to antiretrovirals will need to be investigated. IVRs should not

Experimental and numerical models of three-dimensional gravity-driven flow of shear-thinning polymer solutions used in vaginal delivery of microbicides.

Science.gov (United States)

Kheyfets, Vitaly O; Kieweg, Sarah L

2013-06-01

HIV/AIDS is a growing global pandemic. A microbicide is a formulation of a pharmaceutical agent suspended in a delivery vehicle, and can be used by women to protect themselves against HIV infection during intercourse. We have developed a three-dimensional (3D) computational model of a shear-thinning power-law fluid spreading under the influence of gravity to represent the distribution of a microbicide gel over the vaginal epithelium. This model, accompanied by a new experimental methodology, is a step in developing a tool for optimizing a delivery vehicle's structure/function relationship for clinical application. We compare our model with experiments in order to identify critical considerations for simulating 3D free-surface flows of shear-thinning fluids. Here we found that neglecting lateral spreading, when modeling gravity-induced flow, resulted in up to 47% overestimation of the experimental axial spreading after 90 s. In contrast, the inclusion of lateral spreading in 3D computational models resulted in rms errors in axial spreading under 7%. In addition, the choice of the initial condition for shape in the numerical simulation influences the model's ability to describe early time spreading behavior. Finally, we present a parametric study and sensitivity analysis of the power-law parameters' influence on axial spreading, and to examine the impact of changing rheological properties as a result of dilution or formulation conditions. Both the shear-thinning index (n) and consistency (m) impacted the spreading length and deceleration of the moving front. The sensitivity analysis showed that gels with midrange m and n values (for the ranges in this study) would be most sensitive (over 8% changes in spreading length) to 10% changes (e.g., from dilution) in both rheological properties. This work is applicable to many industrial and geophysical thin-film flow applications of non-Newtonian fluids; in addition to biological applications in microbicide drug delivery.

Clinical use of vaginal or rectally applied microbicides in patients suffering from HIV/AIDS

OpenAIRE

Gupta, Satish; Vinu,Nutan

2013-01-01

Satish Kumar Gupta, Nutan Reproductive Cell Biology Laboratory, National Institute of Immunology, New Delhi, India Abstract: Microbicides, primarily used as topical pre-exposure prophylaxis, have been proposed to prevent sexual transmission of HIV. This review covers the trends and challenges in the development of safe and effective microbicides to prevent sexual transmission of HIV. Initial phases of microbicide development used such surfactants as nonoxynol-9 (N-9), C13G, and sodium lauryl...

Microbicide trials for preventing HIV/AIDS in South Africa: phase II trial partricipants' experiences and psychological needs

NARCIS (Netherlands)

Pistorius, A. G.; van de Wijgert, J. H. H. M.; Sebola, M.; Friedland, B.; Nagel, E.; Bokaba, C.; Hoosen, A. A.

2004-01-01

The Microbicide Division of the Department of Medical Microbiology at MEDUNSA, South Africa, recently completed a phase II expanded safety trial of the candidate microbicide Carraguard. A microbicide is a vaginal product that women might use, if proven safe and effective, to protect themselves from

Vaginal rings for delivery of HIV microbicides

Directory of Open Access Journals (Sweden)

McCoy CF

2012-11-01

Full Text Available R Karl Malcolm, Susan M Fetherston, Clare F McCoy, Peter Boyd, Ian MajorSchool of Pharmacy, Queen's University Belfast, Belfast, UKAbstract: Following the successful development of long-acting steroid-releasing vaginal ring devices for the treatment of menopausal symptoms and contraception, there is now considerable interest in applying similar devices to the controlled release of microbicides against HIV. In this review article, the vaginal ring concept is first considered within the wider context of the early advances in controlled-release technology, before describing the various types of ring device available today. The remainder of the article highlights the key developments in HIV microbicide-releasing vaginal rings, with a particular focus on the dapivirine ring that is presently in late-stage clinical testing.Keywords: controlled release, sustained release, antiretroviral, dapivirine, SILCS diaphragm, silicone elastomer, thermoplastic

Influences of geo-spatial location on pre-exposure prophylaxis use in South Africa: positioning microbicides for better product uptake.

Science.gov (United States)

Govender, Eliza M; Mansoor, Leila E; Abdool Karim, Quarraisha

2017-06-01

Young women bear a disproportionately high burden of HIV infection in sub-Saharan Africa, prioritising pre-exposure prophylaxis (PrEP) can be an integral part of HIV prevention combination strategies. Women initiated HIV prevention technology options will require consistent adherence, an imperative for product effectiveness. With several PrEP clinical trials underway; exploring women's acceptability to advances in HIV prevention technologies can better facilitate demand creation for future PrEP roll out. This study utilised the opportunity of post-trial access to CAPRISA 008 women (trial) and non-trial women from three geo-spatial settings (urban, rural and peri-urban) to identify microbicide acceptability and how product associations of microbicides can influence future HIV prevention choices. Six participatory workshops using participatory action research with art-based activities and discussion groups were conducted in KwaZulu-Natal with 104 women from various geo-spatial locations and social status to understand microbicide acceptability and product associations. The data were analysed using thematic analysis. The study found that women's acceptability and product association of the tenofovir gel microbicide differed according to rural and urban areas. Most urban women identified confidence, sexiness and classiness as key associations that will encourage microbicide acceptability and use, while rural women identified respect, responsibility and confidence as the key product associations, with increased focus on the individual and collective family/community benefits of product acceptance and use. Urban-rural differences suggest a market segmentation that is contextualised to be locally responsive to promote HIV prevention technologies. Various sexual encounters further determined the types of HIV prevention technologies women would consider. In line with WHO's recommendation that PrEP should be an additional prevention choice for people at risk of HIV, this

Adolescent girls' communication with "mothers" about topical microbicides.

Science.gov (United States)

Sunder, Punita K; Ramos, Stephanie; Short, Mary B; Rosenthal, Susan L

2006-12-01

Topical microbicides, a female-initiated method to protect against sexually transmitted infections (STI) and pregnancy, will only be effective if found acceptable. Mothers may have an influence on acceptability and use among adolescent girls. The current study examined the communication between girls and mothers to understand the potential predictors and nature of conversations regarding surrogate microbicide products. Sexually experienced girls, 14 to 21 years, were recruited for a 6-month study examining microbicide acceptability. During face-to-face interviews, qualitative data were collected regarding communication between girls and mothers. Two independent raters coded the responses, which were organized into themes. Themes were interpreted according to the conceptual understanding of mother-daughter communication. Fifty percent of the 171 girls with codable responses had a conversation with their mother. Higher levels of indirect parental monitoring were related to being more likely to have a conversation. Concrete events related to the study (i.e. receiving phone call from the researcher, having an appointment, or seeing the product) or inquiries by mothers appeared to promote conversation. Barriers to conversation included the private nature of the information and relationship issues between the mother and daughter. Conversations often addressed issues related to girls' participation in the study, although some conversations included global issues related to sexuality. Girls may talk to their mothers about new products for STI prevention, and such conversations may provide opportunities to promote use.

Qualitative and quantitative intravaginal targeting: key to anti-HIV-1 microbicide delivery from test tube to in vivo success.

Science.gov (United States)

Pillay, Viness; Mashingaidze, Felix; Choonara, Yahya E; Du Toit, Lisa C; Buchmann, Eckhart; Maharaj, Vinesh; Ndesendo, Valence M K; Kumar, Pradeep

2012-06-01

The past decade has seen several effective anti-HIV-1 agent discoveries, yet microbicides continue to disappoint clinically. Our review expounds the view that unsatisfactory microbicide failures may be a result of inefficient delivery systems employed. We hereby propose a thorough scientific qualitative and quantitative investigation of important aspects involved in HIV-1 transmission as a prerequisite for microbicide delivery. Intravaginal targeting of HIV-1 increases the chances of microbicide success, wherein vaginal microenvironmental factors including pH should be maintained at HIV-1 prohibitive acidic levels simultaneously to ward off other sexually transmitted diseases, which compromise vaginal epithelial barrier properties. Furthermore, choice of receptors to target both on HIV-1 and on target cells is vital in deterring transmission. Appropriate modeling of virus-target cell interactions as well as targeting early stages of the HIV-1 infection accompanied by computation and delivery of appropriate microbicide quantities could revolutionize microbicide research, ultimately delivering a female-controlled HIV-1 prevention modality appropriately. Copyright © 2012 Wiley Periodicals, Inc.

Knowledge and perception of microbicides among healthcare ...

African Journals Online (AJOL)

2014-06-02

Jun 2, 2014 ... mankind has tried several prevention options since the onset of the ... Knowledge and perception of microbicides among healthcare providers in Calabar,. Nigeria .... primary source of reproductive health information for ... are a new group of substances that can reduce the risk .... Research process Report.

Vaginal microbicides: detecting toxicities in vivo that paradoxically increase pathogen transmission

Directory of Open Access Journals (Sweden)

Abusuwwa Raed

2006-06-01

Full Text Available Abstract Background Microbicides must protect against STD pathogens without causing unacceptable toxic effects. Microbicides based on nonoxynol-9 (N9 and other detergents disrupt sperm, HSV and HIV membranes, and these agents are effective contraceptives. But paradoxically N9 fails to protect women against HIV and other STD pathogens, most likely because it causes toxic effects that increase susceptibility. The mouse HSV-2 vaginal transmission model reported here: (a Directly tests for toxic effects that increase susceptibility to HSV-2, (b Determines in vivo whether a microbicide can protect against HSV-2 transmission without causing toxicities that increase susceptibility, and (c Identifies those toxic effects that best correlate with the increased HSV susceptibility. Methods Susceptibility was evaluated in progestin-treated mice by delivering a low-dose viral inoculum (0.1 ID50 at various times after delivering the candidate microbicide to detect whether the candidate increased the fraction of mice infected. Ten agents were tested – five detergents: nonionic (N9, cationic (benzalkonium chloride, BZK, anionic (sodium dodecylsulfate, SDS, the pair of detergents in C31G (C14AO and C16B; one surface active agent (chlorhexidine; two non-detergents (BufferGel®, and sulfonated polystyrene, SPS; and HEC placebo gel (hydroxyethylcellulose. Toxic effects were evaluated by histology, uptake of a 'dead cell' dye, colposcopy, enumeration of vaginal macrophages, and measurement of inflammatory cytokines. Results A single dose of N9 protected against HSV-2 for a few minutes but then rapidly increased susceptibility, which reached maximum at 12 hours. When applied at the minimal concentration needed for brief partial protection, all five detergents caused a subsequent increase in susceptibility at 12 hours of ~20–30-fold. Surprisingly, colposcopy failed to detect visible signs of the N9 toxic effect that increased susceptibility at 12 hours. Toxic

Time-resolved imaging refractometry of microbicidal films using quantitative phase microscopy.

Science.gov (United States)

Rinehart, Matthew T; Drake, Tyler K; Robles, Francisco E; Rohan, Lisa C; Katz, David; Wax, Adam

2011-12-01

Quantitative phase microscopy is applied to image temporal changes in the refractive index (RI) distributions of solutions created by microbicidal films undergoing hydration. We present a novel method of using an engineered polydimethylsiloxane structure as a static phase reference to facilitate calibration of the absolute RI across the entire field. We present a study of dynamic structural changes in microbicidal films during hydration and subsequent dissolution. With assumptions about the smoothness of the phase changes induced by these films, we calculate absolute changes in the percentage of film in regions across the field of view.

Microbicides in the prevention of HIV infection: current status and future directions.

Science.gov (United States)

Nuttall, Jeremy

2010-07-09

More than 28 years since the first cases of HIV/AIDS, there is still no cure or vaccine. The worst affected region is sub-Saharan Africa and, increasingly, it is young women who are bearing the brunt of the epidemic. Consequently, there is an urgent need for HIV prevention options for women in developing countries. Microbicides are topical products that can be used vaginally by women to impede sexual transmission of HIV and thus represent one of the most promising prevention strategies. Efficacy trials with early nonspecific microbicide gels have so far been unsuccessful, but the field has now switched its focus to products containing highly potent and highly specific antiretroviral drugs that are easier to use, and can be formulated in a variety of dosage forms to suit individual and regional preferences. However, these products have their own challenges, with a greater likelihood of absorption, and the potential for systemic toxicities or the development of resistance in infected individuals who are unaware of their HIV status. The conduct of clinical trials is complex for all microbicides, with limited availability of trial sites, difficulties in dose selection and safety monitoring, and a lack of a truly objective measure of adherence. Once a microbicide has been shown to be safe and effective, there will need to be a clear pathway to regulatory approval, and the successful launch of a product will depend on having in place appropriate methods for distribution to the women who need it, along with a strategy for ensuring that they use it correctly. This will require substantial effort in terms of education and community engagement, and these activities need to be initiated well in advance of microbicide rollout.

A social ecology of rectal microbicide acceptability among young men who have sex with men and transgender women in Thailand.

Science.gov (United States)

Newman, Peter A; Roungprakhon, Surachet; Tepjan, Suchon

2013-08-01

rectal microbicide acceptability suggests that social-structural interventions to ensure widespread access, low cost and to mitigate stigma and discrimination against gay and other MSM and transgender women in the Thai health care system and broader society will support the effectiveness of rectal microbicides, in combination with other prevention technologies, in reducing HIV transmission. Education, outreach and small-group interventions that acknowledge differences between MSM and transgender women may support rectal microbicide implementation among most-at-risk populations in Thailand.

Short communication: expression of transporters and metabolizing enzymes in the female lower genital tract: implications for microbicide research.

Science.gov (United States)

Zhou, Tian; Hu, Minlu; Cost, Marilyn; Poloyac, Samuel; Rohan, Lisa

2013-11-01

Topical vaginal microbicides have been considered a promising option for preventing the male-to-female sexual transmission of HIV; however, clinical trials to date have not clearly demonstrated robust and reproducible effectiveness results. While multiple approaches may help enhance product effectiveness observed in clinical trials, increasing the drug exposure in lower genital tract tissues is a compelling option, given the difficulty in achieving sufficient drug exposure and positive correlation between tissue exposure and microbicide efficacy. Since many microbicide drug candidates are substrates of transporters and/or metabolizing enzymes, there is emerging interest in improving microbicide exposure and efficacy through local modulation of transporters and enzymes in the female lower genital tract. However, no systematic information on transporter/enzyme expression is available for ectocervical and vaginal tissues of premenopausal women, the genital sites most relevant to microbicide drug delivery. The current study utilized reverse transcriptase polymerase chain reaction (RT-PCR) to examine the mRNA expression profile of 22 transporters and 19 metabolizing enzymes in premenopausal normal human ectocervix and vagina. Efflux and uptake transporters important for antiretroviral drugs, such as P-gp, BCRP, OCT2, and ENT1, were found to be moderately or highly expressed in the lower genital tract as compared to liver. Among the metabolizing enzymes examined, most CYP isoforms were not detected while a number of UGTs such as UGT1A1 were highly expressed. Moderate to high expression of select transporters and enzymes was also observed in mouse cervix and vagina. The implications of this information on microbicide research is also discussed, including microbicide pharmacokinetics, the utilization of the mouse model in microbicide screening, as well as the in vivo functional studies of cervicovaginal transporters and enzymes.

Rational design of HIV vaccine and microbicides: report of the EUROPRISE annual conference.

Science.gov (United States)

Wahren, Britta; Biswas, Priscilla; Borggren, Marie; Coleman, Adam; Da Costa, Kelly; De Haes, Winni; Dieltjens, Tessa; Dispinseri, Stefania; Grupping, Katrijn; Hallengärd, David; Hornig, Julia; Klein, Katja; Mainetti, Lara; Palma, Paolo; Reudelsterz, Marc; Seifried, Janna; Selhorst, Philippe; Sköld, Annette; Uchtenhagen, Hannes; van Gils, Marit J; Weber, Caroline; Shattock, Robin; Scarlatti, Gabriella

2010-07-26

EUROPRISE is a Network of Excellence sponsored from 2007 to 2011 by the European Commission within the 6th Framework Program. The Network encompasses a wide portfolio of activities ranging from an integrated research program in the field of HIV vaccines and microbicides to training, dissemination and advocacy. The research program covers the whole pipeline of vaccine and microbicide development from discovery to early clinical trials. The Network is composed of 58 partners representing more than 65 institutions from 13 European countries; it also includes three major pharmaceutical companies (GlaxoSmithKline, Novartis and Sanofi-Pasteur) involved in HIV microbicide and vaccine research. The Network displays a dedicated and informative web page: http://www.europrise.org. Finally, a distinguishing trait of EUROPRISE is its PhD School of students from across Europe, a unique example in the world of science aimed at spreading excellence through training. EUROPRISE held its second annual conference in Budapest in November, 2009. The conference had 143 participants and their presentations covered aspects of vaccine and microbicide research, development and discovery. Since training is a major task of the Network, the students of the EUROPRISE PhD program summarized certain presentations and their view of the conference in this paper.

Rational design of HIV vaccine and microbicides: report of the EUROPRISE annual conference

Directory of Open Access Journals (Sweden)

Mainetti Lara

2010-07-01

Full Text Available Abstract EUROPRISE is a Network of Excellence sponsored from 2007 to 2011 by the European Commission within the 6th Framework Program. The Network encompasses a wide portfolio of activities ranging from an integrated research program in the field of HIV vaccines and microbicides to training, dissemination and advocacy. The research program covers the whole pipeline of vaccine and microbicide development from discovery to early clinical trials. The Network is composed of 58 partners representing more than 65 institutions from 13 European countries; it also includes three major pharmaceutical companies (GlaxoSmithKline, Novartis and Sanofi-Pasteur involved in HIV microbicide and vaccine research. The Network displays a dedicated and informative web page: http://www.europrise.org. Finally, a distinguishing trait of EUROPRISE is its PhD School of students from across Europe, a unique example in the world of science aimed at spreading excellence through training. EUROPRISE held its second annual conference in Budapest in November, 2009. The conference had 143 participants and their presentations covered aspects of vaccine and microbicide research, development and discovery. Since training is a major task of the Network, the students of the EUROPRISE PhD program summarized certain presentations and their view of the conference in this paper.

In vitro and ex vivo testing of tenofovir shows it is effective as an HIV-1 microbicide.

Directory of Open Access Journals (Sweden)

Lisa C Rohan

2010-02-01

Full Text Available Tenofovir gel has entered into clinical trials for use as a topical microbicide to prevent HIV-1 infection but has no published data regarding pre-clinical testing using in vitro and ex vivo models. To validate our findings with on-going clinical trial results, we evaluated topical tenofovir gel for safety and efficacy. We also modeled systemic application of tenofovir for efficacy.Formulation assessment of tenofovir gel included osmolality, viscosity, in vitro release, and permeability testing. Safety was evaluated by measuring the effect on the viability of vaginal flora, PBMCs, epithelial cells, and ectocervical and colorectal explant tissues. For efficacy testing, PBMCs were cultured with tenofovir or vehicle control gels and HIV-1 representing subtypes A, B, and C. Additionally, polarized ectocervical and colorectal explant cultures were treated apically with either gel. Tenofovir was added basolaterally to simulate systemic application. All tissues were challenged with HIV-1 applied apically. Infection was assessed by measuring p24 by ELISA on collected supernatants and immunohistochemistry for ectocervical explants. Formulation testing showed the tenofovir and vehicle control gels were >10 times isosmolar. Permeability through ectocervical tissue was variable but in all cases the receptor compartment drug concentration reached levels that inhibit HIV-1 infection in vitro. The gels were non-toxic toward vaginal flora, PBMCs, or epithelial cells. A transient reduction in epithelial monolayer integrity and epithelial fracture for ectocervical and colorectal explants was noted and likely due to the hyperosmolar nature of the formulation. Tenofovir gel prevented HIV-1 infection of PBMCs regardless of HIV-1 subtype. Topical and systemic tenofovir were effective at preventing HIV-1 infection of explant cultures.These studies provide a mechanism for pre-clinical prediction of safety and efficacy of formulated microbicides. Tenofovir was effective

Comparison of the Microbicidal activity of monochloramine and iodine.

Science.gov (United States)

Arnitz, R; Nagl, M; Gottardi, W

2015-12-01

Recently, we showed that monochloramine (NH2 Cl) has a significantly stronger bactericidal and fungicidal activity than chloramine T despite its lower oxidizing power. This phenomenon was explained by increased penetration because of the higher lipophilicity and smaller bulk of NH2 Cl. As iodine (I2 ) has an even fivefold higher bulk than NH2 Cl, a comparison of both compounds regarding their microbicidal activity became the aim of this study. Aqueous solutions of I2 at a concentration of 10·7 μmol l(-1) killed 10(6) colony forming units per millilitre (CFU ml(-1) ) of Escherichia coli, Staphylococcus aureus or Pseudomonas aeruginosa to the detection limit of 10(2) CFU ml(-1) within 1 min at 20°C and pH 7·1, while a concentration of 36-355 μmol l(-1) of NH2 Cl was needed to achieve the same effect. Aspergillus fumigatus was inactivated within 5 min by 36 μmol l(-1) I2 and by 355 μmol l(-1) NH2 Cl, Candida albicans within 1 min by 10·7 μmol l(-1) I2 and by 355 μmol l(-1) NH2 Cl. The lipophilicity of I2 , determined with the octanol/water method, was three powers of 10 higher than that of NH2 Cl. The at least 10-fold stronger microbicidal activity of iodine suggests that the hindrance of penetration of the bulky molecule is outweighed by enhanced lipophilicity. The microbicidal activity of active halogen compounds increases not only with their reactivity, but also with higher lipophilicity and lower bulk, as shown recently. In this study, iodine showed a higher microbicidal activity than monochloramine and a 1000-fold higher lipophilicity. Therefore, the lipophilicity of a disinfectant may be more important than the bulk for bactericidal activity. These facts should be considered upon the design of new antiseptics and their clinical application. © 2015 The Society for Applied Microbiology.

The use of supersaturation for the vaginal application of microbicides

DEFF Research Database (Denmark)

Grammen, Carolien; Plum, Jakob; Van Den Brande, Jeroen

2014-01-01

In this study, we investigated the potential of supersaturation for the formulation of the poorly water-soluble microbicide dapivirine (DPV) in an aqueous vaginal gel in order to enhance its vaginal tissue uptake. Different excipients such as hydroxypropylmethylcellulose, polyethylene glycol 1000....... The best performing supersaturated gel containing 500 μM DPV (supersaturation degree of 4) in the presence of sulfobutyl ether-beta-cyclodextrin (2.5%) appeared to be stable for at least 3 months. In addition, the gel generated a significant increase in vaginal drug uptake in rabbits as compared...... with suspension gels. We conclude that supersaturation is a possible strategy to enhance the vaginal concentration of hydrophobic microbicides, thereby increasing permeation into the vaginal submucosa....

Adolescent Girls’ Communication with “Mothers” About Topical Microbicides

Science.gov (United States)

Sunder, Punita K.; Ramos, Stephanie; Short, Mary B.; Rosenthal, Susan L.

2007-01-01

Study Objective Topical microbicides, a female-initiated method to protect against sexually transmitted infections (STIs) and pregnancy, will only be effective if found acceptable. Mothers may have an influence on acceptability and use among adolescent girls. The current study examined the communication between girls and mothers to understand the potential predictors and nature of conversations regarding surrogate microbicide products. Design Sexually experienced girls, 14 to 21 years, were recruited for a 6-month study examining microbicide acceptability. During face-to-face interviews, qualitative data were collected regarding communication between girls and mothers. Two independent raters coded the responses, which were organized into themes. Themes were interpreted according to the conceptual understanding of mother-daughter communication. Results Fifty percent of the 171 girls with codable responses had a conversation with their mother. Higher levels of indirect parental monitoring were related to being more likely to have a conversation. Concrete events related to the study (i.e. receiving phone call from the researcher, having an appointment, or seeing the product) or inquiries by mothers appeared to promote conversation. Barriers to conversation included the private nature of the information and relationship issues between the mother and daughter. Conversations often addressed issues related to girls’ participation in the study, although some conversations included global issues related to sexuality. Conclusions Girls may talk to their mothers about new products for STI prevention, and such conversations may provide opportunities to promote use. PMID:17174825

How important is the myeloperoxidase microbicidal system of phagocytic cells?

Science.gov (United States)

Thong, Y H

1982-03-01

The myeloperoxidase system is presented by most immunology textbooks as a major microbicidal system of phagocytic cells. This theory, however, has not bee subjected to vigorous testing in the clinical arena. Of 14 patients with primary myeloperoxidase deficiency, only 3 had infectious complication. All 3 patients have more plausible explanation than myeloperoxidase deficiency for their infectious complications. Two of these patients were healthy until middle age when they developed systemic candidiasis after the onset of diabetes mellitus. The third patient was an infant with a maturational defect in neutrophil chemotaxis whose infectious complications ceased after the normalization of the chemotactic defect. The results of these "experiments of nature" indicate that the meyloperoxidase system is not a major microbicidal mechanism of phagocytic cells.

Acceptability of vaginal microbicides among female sex workers and their intimate male partners in two Mexico-US border cities: a mixed methods analysis.

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Robertson, Angela M; Syvertsen, Jennifer L; Martinez, Gustavo; Rangel, M Gudelia; Palinkas, Lawrence A; Stockman, Jamila K; Ulibarri, Monica D; Strathdee, Steffanie A

2013-01-01

Female sex workers (FSWs) may benefit from pre-exposure prophylaxis (PrEP) including microbicides for HIV prevention. Since adherence is a key factor in PrEP efficacy, we explored microbicide acceptability and potential barriers to use within FSWs' intimate relationships in Tijuana and Ciudad Juárez, Mexico, where HIV prevalence is increasing. FSWs and their verified intimate (non-commercial) male partners completed quantitative and qualitative interviews from 2010 to 2012. Our complementary mixed methods design followed an iterative process to assess microbicide acceptability, explore related relationship dynamics and identify factors associated with concern about male partners' anger regarding microbicide use. Among 185 couples (n=370 individuals), interest in microbicides was high. In qualitative interviews with 28 couples, most participants were enthusiastic about microbicides for sex work contexts but some explained that microbicides could imply mistrust/infidelity within their intimate relationships. In the overall sample, nearly one in six participants (16%) worried that male partners would become angry about microbicides, which was associated with higher self-esteem among FSWs and lower self-esteem and past year conflicts causing injury within relationships among men. HIV prevention interventions should consider intimate relationship dynamics posing potential barriers to PrEP acceptability and adherence, involve male partners and promote risk communication skills.

Broad Spectrum Microbicidal Activity of Photocatalysis by TiO2

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Yoshinobu Kubota

2013-03-01

Full Text Available Photocatalytically active titanium dioxide (TiO2 is widely used as a self-cleaning and self-disinfecting material in many applications to keep environments biologically clean. Several studies on the inactivation of bacteria and viruses by photocatalytic reactions have also been reported; however, only few studies evaluated the spectrum of the microbicidal activity with photocatalysis for various species. There is a need to confirm the expected effectiveness of disinfection by photocatalysis against multidrug-resistant bacteria and viruses. In this study, microbicidal activity of photocatalysis was evaluated by comparing the inactivation of various species of bacteria and viruses when their suspensions were dropped on the surface of TiO2-coated glass. Gram-positive bacteria, e.g., methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecalis, and penicillin-resistant Streptococcus pneumoniae, were easily inactivated by photocatalysis, whereas some gram-negative bacteria, e.g., Escherichia coli and multidrug-resistant Pseudomonas aeruginosa, were gradually inactivated by photocatalysis. Influenza virus, an enveloped virus, was significantly inactivated by photocatalysis compared with feline calicivirus, a non-enveloped virus. The effectiveness of microbicidal activity by photocatalysis may depend on the surface structure. However, they are effectively inactivated by photocatalysis on the surface of TiO2-coated glass. Our data emphasize that effective cleaning and disinfection by photocatalysis in nosocomial settings prevents pathogen transmission.

Pregnancy incidence and risk factors among women participating in vaginal microbicide trials for HIV prevention: systematic review and meta-analysis.

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Alfred Musekiwa

Full Text Available INTRODUCTION: Pregnancy is contraindicated in vaginal microbicide trials for the prevention of HIV infection in women due to the unknown maternal and fetal safety of the microbicides. Women who become pregnant are taken off the microbicide during pregnancy period but this result in reduction of the power of the trials. Strategies to reduce the pregnancy rates require an understanding of the incidence and associated risk factors of pregnancy in microbicide trials. This systematic review estimates the overall incidence rate of pregnancy in microbicide trials and describes the associated risk factors. METHODS: A comprehensive literature search was carried out to identify eligible studies from electronic databases and other sources. Two review authors independently selected studies and extracted relevant data from included studies. Meta-analysis of incidence rates of pregnancy was carried out and risk factors of pregnancy were reported narratively. RESULTS: Fifteen studies reporting data from 10 microbicide trials (N=27,384 participants were included. A total of 4,107 participants (15.0% fell pregnant and a meta-analysis of incidence rates of pregnancy from 8 microbicide trials (N=25,551 yielded an overall incidence rate of 23.37 (95%CI: 17.78 to 28.96 pregnancies per 100 woman-years. However, significant heterogeneity was detected. Hormonal injectable, intra-uterine device (IUD or implants or sterilization, older age, more years of education and condom use were associated with lower pregnancy. On the other hand, living with a man, history of pregnancy, self and partner desire for future baby, oral contraceptive use, increased number of unprotected sexual acts and inconsistent use of condoms were associated with higher pregnancy. CONCLUSIONS: The incidence rate of pregnancy in microbicide trials is high and strategies for its reduction are urgently required in order to improve the sample size and power of these trials.

Acceptability of vaginal microbicides among female sex workers and their intimate male partners in two Mexico-U.S. border cities: a mixed methods analysis

Science.gov (United States)

Robertson, Angela M.; Syvertsen, Jennifer L.; Martinez, Gustavo; Rangel, M. Gudelia; Palinkas, Lawrence A.; Stockman, Jamila K.; Ulibarri, Monica D.; Strathdee, Steffanie A.

2013-01-01

Background Female sex workers (FSWs) may benefit from pre-exposure prophylaxis (PrEP) including microbicides for HIV prevention. Since adherence is a key factor in PrEP efficacy, we explored microbicide acceptability and potential barriers to use within FSWs’ intimate relationships in Tijuana and Ciudad Juárez, Mexico, where HIV prevalence is increasing. Methods FSWs and their verified intimate (non-commercial) male partners completed quantitative and qualitative interviews from 2010–2012. Our complementary mixed methods design followed an iterative process to assess microbicide acceptability, explore related relationship dynamics, and identify factors associated with concern about male partners’ anger regarding microbicide use. Results Among 185 couples (n=370 individuals), interest in microbicides was high. In qualitative interviews with 28 couples, most participants were enthusiastic about microbicides for sex work contexts but some explained that microbicides could imply mistrust/infidelity within their intimate relationships. In the overall sample, nearly 1 in 6 participants (16%) worried that male partners would become angry about microbicides, which was associated with higher self-esteem among FSWs and lower self-esteem and past year conflict causing injury within relationships among men. Conclusions HIV prevention interventions should consider intimate relationship dynamics posing potential barriers to PrEP acceptability and adherence, involve male partners, and promote risk communication skills. PMID:23398385

Superior Efficacy of a Human Immunodeficiency Virus Vaccine Combined with Antiretroviral Prevention in Simian-Human Immunodeficiency Virus-Challenged Nonhuman Primates.

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Le Grand, Roger; Dereuddre-Bosquet, Nathalie; Dispinseri, Stefania; Gosse, Leslie; Desjardins, Delphine; Shen, Xiaoying; Tolazzi, Monica; Ochsenbauer, Christina; Saidi, Hela; Tomaras, Georgia; Prague, Mélanie; Barnett, Susan W; Thiebaut, Rodolphe; Cope, Alethea; Scarlatti, Gabriella; Shattock, Robin J

2016-06-01

Although vaccines and antiretroviral (ARV) prevention have demonstrated partial success against human immunodeficiency virus (HIV) infection in clinical trials, their combined introduction could provide more potent protection. Furthermore, combination approaches could ameliorate the potential increased risk of infection following vaccination in the absence of protective immunity. We used a nonhuman primate model to determine potential interactions of combining a partially effective ARV microbicide with an envelope-based vaccine. The vaccine alone provided no protection from infection following 12 consecutive low-dose intravaginal challenges with simian-HIV strain SF162P3, with more animals infected compared to naive controls. The microbicide alone provided a 68% reduction in the risk of infection relative to that of the vaccine group and a 45% reduction relative to that of naive controls. The vaccine-microbicide combination provided an 88% reduction in the per-exposure risk of infection relative to the vaccine alone and a 79% reduction relative to that of the controls. Protected animals in the vaccine-microbicide group were challenged a further 12 times in the absence of microbicide and demonstrated a 98% reduction in the risk of infection. A total risk reduction of 91% was observed in this group over 24 exposures (P = 0.004). These important findings suggest that combined implementation of new biomedical prevention strategies may provide significant gains in HIV prevention. There is a pressing need to maximize the impact of new biomedical prevention tools in the face of the 2 million HIV infections that occur each year. Combined implementation of complementary biomedical approaches could create additive or synergistic effects that drive improved reduction of HIV incidence. Therefore, we assessed a combination of an untested vaccine with an ARV-based microbicide in a nonhuman primate vaginal challenge model. The vaccine alone provided no protection (and may have

Antiviral and immunological effects of tenofovir microbicide in vaginal herpes simplex virus 2 infection.

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Vibholm, Line; Reinert, Line S; Søgaard, Ole S; Paludan, Søren R; Østergaard, Lars; Tolstrup, Martin; Melchjorsen, Jesper

2012-11-01

The anti-HIV microbicide, tenofovir (TFV) gel, has been shown to decrease HIV-1 acquisition by 39% and reduce herpes simplex virus 2 (HSV-2) transmission by 51%. We evaluated the effect of a 1% TFV gel on genital HSV-2 infection in a mouse vaginal challenge model. In vitro plaque assays and luminex multiplex bead analysis were used, respectively, to measure postinfection vaginal viral shedding (day 1) and cytokine secretion (day 2). To further investigate the anti-HSV-2 properties, we evaluated the direct antiviral effect of TFV and the oral prodrug tenofovir disoproxil fumerate (TDF) in cell culture. Compared to placebo-treated mice, TFV-treated mice had significantly lower clinical scores, developed later genital lesions, and showed reduced vaginal viral shedding. Furthermore, the levels of IFN-γ, IL-2, TNF-α, and other cytokines were altered in the vaginal fluid following topical tenofovir treatment and subsequent HSV-2 challenge. Finally, we found that both TFV and TDF inhibited HSV-2 infection in vitro; TDF showed a 50-fold greater potency than TFV. In conclusion, we confirmed that the microbicide TFV had direct anti-HSV-2 effects in a murine vaginal challenge model. Therefore, this model would be suitable for evaluating present and future microbicide candidates. Furthermore, the present study warrants further investigation of TDF in microbicides.

The influence of social constructs of hegemonic masculinity and sexual behaviour on acceptability of vaginal microbicides in Zambia.

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Mweemba, Oliver; Dixey, Rachael; Bond, Virginia; White, Alan

2018-07-01

Vaginal microbicides are heralded as a woman's HIV prevention method. This study, conducted in a microbicide clinical trial setting in Zambia, explored how the social construction of masculinity and sexual behaviour influenced the acceptability of vaginal microbicides. The data were generated from 18 In-depth Interviews and 8 Focus Group Discussions. The data were analysed thematically. The study found that hegemonic masculinity influenced the use of vaginal microbicides positively and negatively, in multiple ways including: decision to initiate gel use, autonomous use of the gel, and consistent use of the gel. Men were seen as heads of households and decision-makers who approved their partners' intentions to initiate gel use. Autonomous gel use by women was not supported because it challenged men's dominant position in sexual matters and at a family level. The socially accepted notion that men engaged in multiple sexual relationships also influenced women's decision to use the gel. Sustained gel use depended on the perceived effect of the gel on men's sexual desires, sexual performance, fertility, and sexual behaviour. This study suggests that acceptability of microbicides partially lies within the realm of men, with use constrained and dictated by cultural constructs and practice of masculinity and gender.

Qualitative and quantitative intravaginal targeting: Key to anti-HIV-1 microbicide delivery from test tube to in vivo success

CSIR Research Space (South Africa)

Pillay, V

2012-06-01

Full Text Available employed. We hereby propose a thorough scientific qualitative and quantitative investigation of important aspects involved in HIV-1 transmission as a prerequisite for microbicide delivery. Intravaginal targeting of HIV-1 increases the chances of microbicide...

A crucial role for plasmacytoid dendritic cells in antiviral protection by CpG ODN–based vaginal microbicide

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Shen, Hong; Iwasaki, Akiko

2006-01-01

Topical microbicides represent a promising new approach to preventing HIV and other sexually transmitted infections. TLR agonists are ideal candidates for microbicides, as they trigger a multitude of antiviral genes effective against a broad range of viruses. Although vaginal application of CpG oligodeoxynucleotides (ODNs) and poly I:C has been shown to protect mice from genital herpes infection, the mechanism by which these agents provide protection remains unclear. Here, we show that plasmacytoid DCs (pDCs) are required for CpG ODN–mediated protection against lethal vaginal challenge with herpes simplex virus type 2 (HSV-2). Moreover, we demonstrate that cells of both the hematopoietic and stromal compartments must respond to CpG ODN via TLR9 and to type I IFNs through IFN-αβ receptor (IFN-αβR) for protection. Thus, crosstalk between pDCs and vaginal stromal cells provides for optimal microbicide efficacy. Our results imply that temporally and spatially controlled targeting of CpG ODN to pDCs and epithelial cells can potentially maximize their effectiveness as microbicides while minimizing the associated inflammatory responses. PMID:16878177

Pharmacokinetic modeling of a gel-delivered dapivirine microbicide in humans.

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Halwes, Michael E; Steinbach-Rankins, Jill M; Frieboes, Hermann B

2016-10-10

Although a number of drugs have been developed for the treatment and prevention of human immunodeficiency virus (HIV) infection, it has proven difficult to optimize the drug and dosage parameters. The vaginal tissue, comprised of epithelial, stromal and blood compartments presents a complex system which challenges evaluation of drug kinetics solely through empirical effort. To provide insight into the underlying processes, mathematical modeling and computational simulation have been applied to the study of retroviral microbicide pharmacokinetics. Building upon previous pioneering work that modeled the delivery of Tenofovir (TFV) via topical delivery to the vaginal environment, here we computationally evaluate the performance of the retroviral inhibitor dapivirine released from a microbicide gel. We adapt the TFV model to simulate the multicompartmental diffusion and uptake of dapivirine into the blood plasma and vaginal compartments. The results show that dapivirine is expected to accumulate at the interface between the gel and epithelium compartments due to its hydrophobic characteristics. Hydrophobicity also results in decreased diffusivity, which may impact distribution by up to 2 orders of magnitude compared to TFV. Maximum concentrations of dapivirine in the epithelium, stroma, and blood were 9.9e7, 2.45e6, and 119pg/mL, respectively. This suggests that greater initial doses or longer time frames are required to obtain higher drug concentrations in the epithelium. These observations may have important ramifications if a specific time frame is required for efficacy, or if a minimum/maximum concentration is needed in the mucus, epithelium, or stroma based on combined efficacy and safety data. Copyright © 2016 Elsevier B.V. All rights reserved.

Historical development of vaginal microbicides to prevent sexual transmission of HIV in women: from past failures to future hopes

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Notario-Pérez F

2017-06-01

Full Text Available Fernando Notario-Pérez, Roberto Ruiz-Caro, María-Dolores Veiga-Ochoa Department of Pharmacy and Pharmaceutical Technology, School of Pharmacy, Universidad Complutense de Madrid, Madrid, Spain Abstract: Infection with human immunodeficiency virus (HIV remains a global public health concern and is particularly serious in low- and middle-income countries. Widespread sexual violence and poverty, among other factors, increase the risk of infection in women, while currently available prevention methods are outside the control of most. This has driven the study of vaginal microbicides to prevent sexual transmission of HIV from men to women in recent decades. The first microbicides evaluated were formulated as gels for daily use and contained different substances such as surfactants, acidifiers and monoclonal antibodies, which failed to demonstrate efficacy in clinical trials. A gel containing the reverse transcriptase inhibitor tenofovir showed protective efficacy in women. However, the lack of adherence by patients led to the search for dosage forms capable of releasing the active principle for longer periods, and hence to the emergence of the vaginal ring loaded with dapivirine, which requires a monthly application and is able to reduce the sexual transmission of HIV. The future of vaginal microbicides will feature the use of alternative dosage forms, nanosystems for drug release and probiotics, which have emerged as potential microbicides but are still in the early stages of development. Protecting women with vaginal microbicide formulations would, therefore, be a valuable tool for avoiding sexual transmission of HIV. Keywords: vaginal formulations, microbicides, prevention, sexual transmission, acquired immunodeficiency syndrome (AIDS, human immunodeficiency virus (HIV

Historical development of vaginal microbicides to prevent sexual transmission of HIV in women: from past failures to future hopes.

Science.gov (United States)

Notario-Pérez, Fernando; Ruiz-Caro, Roberto; Veiga-Ochoa, María-Dolores

2017-01-01

Infection with human immunodeficiency virus (HIV) remains a global public health concern and is particularly serious in low- and middle-income countries. Widespread sexual violence and poverty, among other factors, increase the risk of infection in women, while currently available prevention methods are outside the control of most. This has driven the study of vaginal microbicides to prevent sexual transmission of HIV from men to women in recent decades. The first microbicides evaluated were formulated as gels for daily use and contained different substances such as surfactants, acidifiers and monoclonal antibodies, which failed to demonstrate efficacy in clinical trials. A gel containing the reverse transcriptase inhibitor tenofovir showed protective efficacy in women. However, the lack of adherence by patients led to the search for dosage forms capable of releasing the active principle for longer periods, and hence to the emergence of the vaginal ring loaded with dapivirine, which requires a monthly application and is able to reduce the sexual transmission of HIV. The future of vaginal microbicides will feature the use of alternative dosage forms, nanosystems for drug release and probiotics, which have emerged as potential microbicides but are still in the early stages of development. Protecting women with vaginal microbicide formulations would, therefore, be a valuable tool for avoiding sexual transmission of HIV.

Does microbicide use in consumer products promote antimicrobial resistance? A critical review and recommendations for a cohesive approach to risk assessment.

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Maillard, Jean-Yves; Bloomfield, Sally; Coelho, Joana Rosado; Collier, Phillip; Cookson, Barry; Fanning, Séamus; Hill, Andrew; Hartemann, Philippe; McBain, Andrew J; Oggioni, Marco; Sattar, Syed; Schweizer, Herbert P; Threlfall, John

2013-10-01

The increasing use of microbicides in consumer products is raising concerns related to enhanced microbicide resistance in bacteria and potential cross resistance to antibiotics. The recently published documents on this topic from the European Commission have spawned much interest to better understand the true extent of the putative links for the benefit of the manufacturers, regulators, and consumers alike. This white paper is based on a 2-day workshop (SEAC-Unilever, Bedford, United Kingdom; June 2012) in the fields of microbicide usage and resistance. It identifies gaps in our knowledge and also makes specific recommendations for harmonization of key terms and refinement/standardization of methods for testing microbicide resistance to better assess the impact and possible links with cross resistance to antibiotics. It also calls for a better cohesion in research in this field. Such information is crucial to developing any risk assessment framework on microbicide use notably in consumer products. The article also identifies key research questions where there are inadequate data, which, if addressed, could promote improved knowledge and understanding to assess any related risks for consumer and environmental safety.

Nanotech-derived topical microbicides for HIV prevention: the road to clinical development.

Science.gov (United States)

Sánchez-Rodríguez, Javier; Vacas-Córdoba, Enrique; Gómez, Rafael; De La Mata, F Javier; Muñoz-Fernández, Ma Ángeles

2015-01-01

More than three decades since its discovery, HIV infection remains one of the most aggressive epidemics worldwide, with more than 35 million people infected. In sub-Saharan Africa, heterosexual transmissions represent nearly 80% of new infections, with 50% of these occurring in women. In an effort to stop the dramatic spread of the HIV epidemic, new preventive treatments, such as microbicides, have been developed. Nanotechnology has revolutionized this field by designing and engineering novel highly effective nano-sized materials as microbicide candidates. This review illustrates the most recent advances in nanotech-derived HIV prevention strategies, as well as the main steps required to translate promising in vitro results into clinical trials. Copyright © 2014 Elsevier B.V. All rights reserved.

Combined simulation of energy and thermal management for an electric vehicle

Energy Technology Data Exchange (ETDEWEB)

Mohrmann, Bjoern; Jeck, Peter [Institut fuer Kraftfahrzeuge Aachen (Germany); Simon, Carsten [fortiss GmbH, Muenchen (Germany); Ungermann, Jochen [Audi AG, Ingolstadt (Germany)

2012-11-01

The project eperformance, which is funded by the BMBF, is conducted by project partners from RWTH Aachen, Audi, Bosch Engineering and fortiss GmbH, in order to demonstrate the concept of an electric vehicle on the basis of a holistic development approach. To support this, several simulation platforms come into use, i.e. CFD Simulation for cooling concepts, electromagnetic simulations for electric machine design, physical simulation of cooling circuits as well as vehicle mechanics and controller design. To develop an energy efficient vehicle management, some of these simulation domains have to be combined, to simulate interdependencies between for example usage of high-voltage batteries, their thermal response and the impact for controller strategies. Within the project it was decided to use the Tool TISC (TLK Inter Software Connector) to combine as well a physical model, based on Modelica/Dymola to simulate thermal behaviours of components with a longitudinal vehicle model and a controller model, both based in MATLAB/Simulink. Advantages of such a coupled simulation are the re-usability of existing models in both tools with their tool-specific benefits as well as the possibility to cluster the models on different computers. The article will explain how the combined simulation is set up and parameterized, and will show two use cases: the thermal management of the two independent battery systems of the demonstrator vehicle and the torque distribution on the three electric machines in the vehicle, depending on the drive situation and the thermal state of the machines. (orig)

Toll-Like Receptors and Cytokines as Surrogate Biomarkers for Evaluating Vaginal Immune Response following Microbicide Administration

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Sadhana M. Gupta

2008-01-01

Full Text Available Topical microbicides are intended for frequent use by women in reproductive age. Hence, it is essential to evaluate their impact on mucosal immune function in the vagina. In the present study, we evaluated nisin, a naturally occurring antimicrobial peptide (AMP, for its efficacy as an intravaginal microbicide. Its effect on the vaginal immune function was determined by localizing Toll-like receptors (TLRs-3, 9 and cytokines (IL-4, 6 , 10 and TNF-α in the rabbit cervicovaginal epithelium following intravaginal administration of high dose of nisin gel for 14 consecutive days. The results revealed no alteration in the expression of TLRs and cytokines at both protein and mRNA levels. However, in SDS gel-treated group, the levels were significantly upregulated with the induction of NF-κB signalling cascade. Thus, TLRs and cytokines appear as sensitive indicators for screening immunotoxic potential of candidate microbicides.

Toll-like receptors and cytokines as surrogate biomarkers for evaluating vaginal immune response following microbicide administration.

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Gupta, Sadhana M; Aranha, Clara C; Mohanty, Madhu C; Reddy, K V R

2008-01-01

Topical microbicides are intended for frequent use by women in reproductive age. Hence, it is essential to evaluate their impact on mucosal immune function in the vagina. In the present study, we evaluated nisin, a naturally occurring antimicrobial peptide (AMP), for its efficacy as an intravaginal microbicide. Its effect on the vaginal immune function was determined by localizing Toll-like receptors (TLRs-3, 9) and cytokines (IL-4, 6 , 10 and TNF-alpha) in the rabbit cervicovaginal epithelium following intravaginal administration of high dose of nisin gel for 14 consecutive days. The results revealed no alteration in the expression of TLRs and cytokines at both protein and mRNA levels. However, in SDS gel-treated group, the levels were significantly upregulated with the induction of NF-kappaB signalling cascade. Thus, TLRs and cytokines appear as sensitive indicators for screening immunotoxic potential of candidate microbicides.

Rumours about blood and reimbursements in a microbicide gel trial.

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Stadler, Jonathan; Saethre, Eirik

2010-12-01

A rumour that emerged during a microbicide gel trial tells the tale of clinic staff purchasing trial participants' blood. This paper documents the rumour and explores its divergent interpretations and meanings in relation to the context of the trial and the social and economic setting at two of the trial sites (Soweto and Orange Farm) in South Africa. The article is based on qualitative research conducted during the Microbicides Development Programme (MDP) 301 trial to evaluate a microbicide vaginal gel for HIV prevention in women. The research incorporated in-depth interviews with female trial participants and their male partners, focus group discussions with male and female community members, and participant observation in the trial clinic and community setting at the two sites. The article analyses the different perspectives among the clinic staff, community and trial participants in terms of which the rumour about the exchange of blood for cash is seen as: 1) the result of ignorance of the clinical trial procedures; 2) the exploitation of poor and vulnerable women; 3) an example of young women's desire for material gain; and 4) a reciprocal exchange of 'clean blood' for cash between women trial participants and the health services. We suggest that the rumours about selling blood verbalise notions of gender and morality while also providing an appraisal of the behaviour of young women and a critique of social relationships between foreign researchers and local participants. Through stories about the clinical trial procedures and its potential reimbursements, the participants were creating and reconfiguring social relationships. Ultimately, rumours are one way in which foreign enterprises such as a clinical trial are rendered local.

Willingness to Use Microbicides Is Affected by the Importance of Product Characteristics, Use Parameters, and Protective Properties

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Morrow, Kathleen M.; Fava, Joseph L.; Rosen, Rochelle K.; Vargas, Sara; Barroso, Candelaria; Christensen, Anna L.; Woodsong, Cynthia; Severy, Lawrence

2008-01-01

Background Along with efficacy, a microbicide’s acceptability will be integral to its impact on the pandemic. Understanding Product Characteristics that users find most acceptable and determining who will use which type of product are key to optimizing use effectiveness. Objectives To evaluate psychometrically the Important Microbicide Characteristics (IMC) instrument and examine its relationship to willingness to use microbicides. Results Exploratory and confirmatory factor analyses revealed 2 IMC subscales (Cronbach’s coefficient α: Product Characteristics subscale (α = 0.84) and Protective Properties subscale (α = 0.89)). Significant differences on Product Characteristics subscale scores were found for history of douching (P = 0.002) and employment status (P = 0.001). Whether a woman used a method to prevent pregnancy or sexually transmitted disease (STD) in the last 3 months (P IMC instrument serves as a template for future studies of candidate microbicides. PMID:17325607

Microbicides Development Programme: Engaging the community in the standard of care debate in a vaginal microbicide trial in Mwanza, Tanzania

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Soteli Selephina

2009-10-01

Full Text Available Abstract Background HIV prevention research in resource-limited countries is associated with a variety of ethical dilemmas. Key amongst these is the question of what constitutes an appropriate standard of health care (SoC for participants in HIV prevention trials. This paper describes a community-focused approach to develop a locally-appropriate SoC in the context of a phase III vaginal microbicide trial in Mwanza City, northwest Tanzania. Methods A mobile community-based sexual and reproductive health service for women working as informal food vendors or in traditional and modern bars, restaurants, hotels and guesthouses has been established in 10 city wards. Wards were divided into geographical clusters and community representatives elected at cluster and ward level. A city-level Community Advisory Committee (CAC with representatives from each ward has been established. Workshops and community meetings at ward and city-level have explored project-related concerns using tools adapted from participatory learning and action techniques e.g. chapati diagrams, pair-wise ranking. Secondary stakeholders representing local public-sector and non-governmental health and social care providers have formed a trial Stakeholders' Advisory Group (SAG, which includes two CAC representatives. Results Key recommendations from participatory community workshops, CAC and SAG meetings conducted in the first year of the trial relate to the quality and range of clinic services provided at study clinics as well as broader standard of care issues. Recommendations have included streamlining clinic services to reduce waiting times, expanding services to include the children and spouses of participants and providing care for common local conditions such as malaria. Participants, community representatives and stakeholders felt there was an ethical obligation to ensure effective access to antiretroviral drugs and to provide supportive community-based care for women identified

Microbicides Development Programme: Engaging the community in the standard of care debate in a vaginal microbicide trial in Mwanza, Tanzania

Science.gov (United States)

Vallely, Andrew; Shagi, Charles; Lees, Shelley; Shapiro, Katherine; Masanja, Joseph; Nikolau, Lawi; Kazimoto, Johari; Soteli, Selephina; Moffat, Claire; Changalucha, John; McCormack, Sheena; Hayes, Richard J

2009-01-01

Background HIV prevention research in resource-limited countries is associated with a variety of ethical dilemmas. Key amongst these is the question of what constitutes an appropriate standard of health care (SoC) for participants in HIV prevention trials. This paper describes a community-focused approach to develop a locally-appropriate SoC in the context of a phase III vaginal microbicide trial in Mwanza City, northwest Tanzania. Methods A mobile community-based sexual and reproductive health service for women working as informal food vendors or in traditional and modern bars, restaurants, hotels and guesthouses has been established in 10 city wards. Wards were divided into geographical clusters and community representatives elected at cluster and ward level. A city-level Community Advisory Committee (CAC) with representatives from each ward has been established. Workshops and community meetings at ward and city-level have explored project-related concerns using tools adapted from participatory learning and action techniques e.g. chapati diagrams, pair-wise ranking. Secondary stakeholders representing local public-sector and non-governmental health and social care providers have formed a trial Stakeholders' Advisory Group (SAG), which includes two CAC representatives. Results Key recommendations from participatory community workshops, CAC and SAG meetings conducted in the first year of the trial relate to the quality and range of clinic services provided at study clinics as well as broader standard of care issues. Recommendations have included streamlining clinic services to reduce waiting times, expanding services to include the children and spouses of participants and providing care for common local conditions such as malaria. Participants, community representatives and stakeholders felt there was an ethical obligation to ensure effective access to antiretroviral drugs and to provide supportive community-based care for women identified as HIV positive during

Direct Microbicidal Activity of Cytotoxic T-Lymphocytes

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Paul Oykhman

2010-01-01

Full Text Available Cytotoxic T-lymphocytes (CTL are famous for their ability to kill tumor, allogeneic and virus-infected cells. However, an emerging literature has now demonstrated that CTL also possess the ability to directly recognize and kill bacteria, parasites, and fungi. Here, we review past and recent findings demonstrating the direct microbicidal activity of both CD4+ and CD8+ CTL against various microbial pathogens. Further, this review will outline what is known regarding the mechanisms of direct killing and their underlying signalling pathways.

Analysis of vaginal microbicide film hydration kinetics by quantitative imaging refractometry.

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Rinehart, Matthew; Grab, Sheila; Rohan, Lisa; Katz, David; Wax, Adam

2014-01-01

We have developed a quantitative imaging refractometry technique, based on holographic phase microscopy, as a tool for investigating microscopic structural changes in water-soluble polymeric materials. Here we apply the approach to analyze the structural degradation of vaginal topical microbicide films due to water uptake. We implemented transmission imaging of 1-mm diameter film samples loaded into a flow chamber with a 1.5×2 mm field of view. After water was flooded into the chamber, interference images were captured and analyzed to obtain high resolution maps of the local refractive index and subsequently the volume fraction and mass density of film material at each spatial location. Here, we compare the hydration dynamics of a panel of films with varying thicknesses and polymer compositions, demonstrating that quantitative imaging refractometry can be an effective tool for evaluating and characterizing the performance of candidate microbicide film designs for anti-HIV drug delivery.

Rational design of HIV vaccines and microbicides: report of the EUROPRISE network annual conference 2010

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Uchtenhagen Hannes

2011-04-01

Full Text Available Abstract Novel, exciting intervention strategies to prevent infection with HIV have been tested in the past year, and the field is rapidly evolving. EUROPRISE is a network of excellence sponsored by the European Commission and concerned with a wide range of activities including integrated developmental research on HIV vaccines and microbicides from discovery to early clinical trials. A central and timely theme of the network is the development of the unique concept of co-usage of vaccines and microbicides. This review, prepared by the PhD students of the network captures much of the research ongoing between the partners. The network is in its 5th year and involves over 50 institutions from 13 European countries together with 3 industrial partners; GSK, Novartis and Sanofi-Pasteur. EUROPRISE is involved in 31 separate world-wide trials of Vaccines and Microbicides including 6 in African countries (Tanzania, Mozambique, South Africa, Kenya, Malawi, Rwanda, and is directly supporting clinical trials including MABGEL, a gp140-hsp70 conjugate trial and HIVIS, vaccine trials in Europe and Africa.

Rational design of HIV vaccines and microbicides: report of the EUROPRISE network annual conference 2010.

Science.gov (United States)

Brinckmann, Sarah; da Costa, Kelly; van Gils, Marit J; Hallengärd, David; Klein, Katja; Madeira, Luisa; Mainetti, Lara; Palma, Paolo; Raue, Katharina; Reinhart, David; Reudelsterz, Marc; Ruffin, Nicolas; Seifried, Janna; Schäfer, Katrein; Sheik-Khalil, Enas; Sköld, Annette; Uchtenhagen, Hannes; Vabret, Nicolas; Ziglio, Serena; Scarlatti, Gabriella; Shattock, Robin; Wahren, Britta; Gotch, Frances

2011-04-12

Novel, exciting intervention strategies to prevent infection with HIV have been tested in the past year, and the field is rapidly evolving. EUROPRISE is a network of excellence sponsored by the European Commission and concerned with a wide range of activities including integrated developmental research on HIV vaccines and microbicides from discovery to early clinical trials. A central and timely theme of the network is the development of the unique concept of co-usage of vaccines and microbicides. This review, prepared by the PhD students of the network captures much of the research ongoing between the partners. The network is in its 5th year and involves over 50 institutions from 13 European countries together with 3 industrial partners; GSK, Novartis and Sanofi-Pasteur. EUROPRISE is involved in 31 separate world-wide trials of Vaccines and Microbicides including 6 in African countries (Tanzania, Mozambique, South Africa, Kenya, Malawi, Rwanda), and is directly supporting clinical trials including MABGEL, a gp140-hsp70 conjugate trial and HIVIS, vaccine trials in Europe and Africa.

Testing of viscous anti-HIV microbicides using Lactobacillus

OpenAIRE

Moncla, B.J.; Pryke, K.; Rohan, L. C.; Yang, H.

2011-01-01

The development of topical microbicides for intravaginal use to prevent HIV infection requires that the drugs and formulated products be nontoxic to the endogenous vaginal Lactobacillus. In 30 min exposure tests we found dapivirine, tenofovir and UC781 (reverse transcriptase inhibitor anti-HIV drugs) as pure drugs or formulated as film or gel products were not deleterious to Lactobacillus species; however, PSC-RANTES (a synthetic CCR5 antagonist) killed 2 strains of Lactobacillus jensenii. To...

Inhibition of Human Immunodeficiency Virus Type 1 Infection by the Candidate Microbicide Dapivirine, a Nonnucleoside Reverse Transcriptase Inhibitor▿

OpenAIRE

Fletcher, P.; Harman, S.; Azijn, H.; Armanasco, N.; Manlow, P.; Perumal, D.; de Bethune, M.-P.; Nuttall, J.; Romano, J.; Shattock, R.

2008-01-01

Heterosexual transmission of human immunodeficiency virus (HIV) remains the major route of infection worldwide; thus, there is an urgent need for additional prevention strategies, particularly strategies that could be controlled by women, such as topical microbicides. Potential microbicide candidates must be both safe and effective. Using cellular and tissue explant models, we have evaluated the activity of the nonnucleoside reverse transcriptase inhibitor (NNRTI) dapivirine as a vaginal micr...

Quantitative perceptual differences among over-the-counter vaginal products using a standardized methodology: implications for microbicide development.

Science.gov (United States)

Mahan, Ellen D; Morrow, Kathleen M; Hayes, John E

2011-08-01

Increasing prevalence of HIV infection among women worldwide has motivated the development of female-initiated prevention methods, including gel-based microbicides. User acceptability is vital for microbicide success; however, varying cultural vaginal practices indicate multiple formulations must be developed to appeal to different populations. Perceptual attributes of microbicides have been identified as primary drivers of acceptability; however, previous studies do not allow for direct comparison of these qualities between multiple formulations. Six vaginal products were analyzed ex vivo using descriptive analysis. Perceptual attributes of samples were identified by trained participants (n=10) and rated quantitatively using scales based on a panel-developed lexicon. Data were analyzed using two-way ANOVAs for each attribute; product differences were assessed via Tukey's honestly significant difference test. Significant differences were found between products for multiple attributes. Patterns were also seen for attributes across intended product usage (i.e., contraceptive, moisturizer or lubricant). For example, Options© Gynol II® (Caldwell Consumer Health, LLC) was significantly stickier and grainier than other products. Descriptive analysis, a quantitative approach that is based on consensus lexicon usage among participants, successfully quantified perceptual differences among vaginal products. Since perceptual attributes of products can be directly compared quantitatively, this study represents a novel approach that could be used to inform rational design of microbicides. Copyright © 2011 Elsevier Inc. All rights reserved.

Analysis of vaginal microbicide film hydration kinetics by quantitative imaging refractometry.

Directory of Open Access Journals (Sweden)

Matthew Rinehart

Full Text Available We have developed a quantitative imaging refractometry technique, based on holographic phase microscopy, as a tool for investigating microscopic structural changes in water-soluble polymeric materials. Here we apply the approach to analyze the structural degradation of vaginal topical microbicide films due to water uptake. We implemented transmission imaging of 1-mm diameter film samples loaded into a flow chamber with a 1.5×2 mm field of view. After water was flooded into the chamber, interference images were captured and analyzed to obtain high resolution maps of the local refractive index and subsequently the volume fraction and mass density of film material at each spatial location. Here, we compare the hydration dynamics of a panel of films with varying thicknesses and polymer compositions, demonstrating that quantitative imaging refractometry can be an effective tool for evaluating and characterizing the performance of candidate microbicide film designs for anti-HIV drug delivery.

Inhibition of human immunodeficiency virus type 1 infection by the candidate microbicide dapivirine, a nonnucleoside reverse transcriptase inhibitor.

Science.gov (United States)

Fletcher, P; Harman, S; Azijn, H; Armanasco, N; Manlow, P; Perumal, D; de Bethune, M-P; Nuttall, J; Romano, J; Shattock, R

2009-02-01

Heterosexual transmission of human immunodeficiency virus (HIV) remains the major route of infection worldwide; thus, there is an urgent need for additional prevention strategies, particularly strategies that could be controlled by women, such as topical microbicides. Potential microbicide candidates must be both safe and effective. Using cellular and tissue explant models, we have evaluated the activity of the nonnucleoside reverse transcriptase inhibitor (NNRTI) dapivirine as a vaginal microbicide. In tissue compatibility studies, dapivirine was well tolerated by epithelial cells, T cells, macrophages, and cervical tissue explants. Dapivirine demonstrated potent dose-dependent inhibitory effects against a broad panel of HIV type 1 isolates from different clades. Furthermore, dapivirine demonstrated potent activity against a wide range of NNRTI-resistant isolates. In human cervical explant cultures, dapivirine was able not only to inhibit direct infection of mucosal tissue but also to prevent the dissemination of the virus by migratory cells. Activity was retained in the presence of semen or a cervical mucus simulant. Furthermore, dapivirine demonstrated prolonged inhibitory effects: it was able to prevent both localized and disseminated infection for as long as 6 days posttreatment. The prolonged protection observed following pretreatment of genital tissue and the lack of observable toxicity suggest that dapivirine has considerable promise as a potential microbicide candidate.

Inhibition of Human Immunodeficiency Virus Type 1 Infection by the Candidate Microbicide Dapivirine, a Nonnucleoside Reverse Transcriptase Inhibitor▿

Science.gov (United States)

Fletcher, P.; Harman, S.; Azijn, H.; Armanasco, N.; Manlow, P.; Perumal, D.; de Bethune, M.-P.; Nuttall, J.; Romano, J.; Shattock, R.

2009-01-01

Heterosexual transmission of human immunodeficiency virus (HIV) remains the major route of infection worldwide; thus, there is an urgent need for additional prevention strategies, particularly strategies that could be controlled by women, such as topical microbicides. Potential microbicide candidates must be both safe and effective. Using cellular and tissue explant models, we have evaluated the activity of the nonnucleoside reverse transcriptase inhibitor (NNRTI) dapivirine as a vaginal microbicide. In tissue compatibility studies, dapivirine was well tolerated by epithelial cells, T cells, macrophages, and cervical tissue explants. Dapivirine demonstrated potent dose-dependent inhibitory effects against a broad panel of HIV type 1 isolates from different clades. Furthermore, dapivirine demonstrated potent activity against a wide range of NNRTI-resistant isolates. In human cervical explant cultures, dapivirine was able not only to inhibit direct infection of mucosal tissue but also to prevent the dissemination of the virus by migratory cells. Activity was retained in the presence of semen or a cervical mucus simulant. Furthermore, dapivirine demonstrated prolonged inhibitory effects: it was able to prevent both localized and disseminated infection for as long as 6 days posttreatment. The prolonged protection observed following pretreatment of genital tissue and the lack of observable toxicity suggest that dapivirine has considerable promise as a potential microbicide candidate. PMID:19029331

Intravaginal ring delivery of the reverse transcriptase inhibitor TMC 120 as an HIV microbicide.

Science.gov (United States)

Woolfson, A David; Malcolm, R Karl; Morrow, Ryan J; Toner, Clare F; McCullagh, Stephen D

2006-11-15

TMC 120 (Dapivirine) is a potent non-nucleoside reverse transcriptase inhibitor that is presently being developed as a vaginal HIV microbicide. To date, most vaginal microbicides under clinical investigation have been formulated as single-dose semi-solid gels, designed for application to the vagina before each act of intercourse. However, a clear rationale exists for providing long-term, controlled release of vaginal microbicides in order to afford continuous protection against heterosexually transmitted HIV infection and to improve user compliance. In this study we report on the incorporation of various pharmaceutical excipients into TMC 120 silicone, reservoir-type intravaginal rings (IVRs) in order to modify the controlled release characteristics of the microbicide. The results demonstrate that TMC 120 is released in zero-order fashion from the rings over a 28-day period and that release parameters could be modified by the inclusion of release-modifying excipients in the IVR. The hydrophobic liquid excipient isopropyl myristate had little effect on steady-state daily release rates, but did increase the magnitude and duration of burst release in proportion to excipient loading in the IVR. By comparison, the hydrophobic liquid poly(dimethylsiloxane) had little effect on TMC 120 release parameters. A hydrophilic excipient, lactose, had the surprising effect of decreasing TMC 120 burst release while increasing the apparent steady-state daily release in a concentration-dependent manner. Based on previous cell culture data and vaginal physiology, TMC120 is released from the various ring formulations in amounts potentially capable of maintaining a protective vaginal concentration. It is further predicted that the observed release rates may be maintained for at least a period of 1 year from a single ring device. TMC 120 release profiles and the mechanical properties of rings could be modified by the physicochemical nature of hydrophobic and hydrophilic excipients

HIV-1 pseudovirus neutralisation by a natural compound: a potential microbicide

CSIR Research Space (South Africa)

Van den Berg, N

2011-02-01

Full Text Available . The mode of action of the compound is, however, yet to be determined. The aim is to develop a microbicide based on an indigenous plant for people infected with HIV-1. The compound will also be screened against other HIV-1 subtypes to test the neutralisation...

Vaginal microbicides for reducing the risk of sexual acquisition of HIV infection in women: systematic review and meta-analysis

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Obiero Jael

2012-11-01

Full Text Available Abstract Background Each year more than two million people are newly infected with HIV worldwide, a majority of them through unprotected vaginal sex. More than half of new infections in adults occur in women. Male condoms and male circumcision reduce the risk of HIV acquisition; but the uptake of these methods is out of the control of women. We therefore aimed to determine the effectiveness of vaginal microbicides (a potential female-controlled method for prevention of sexual acquisition of HIV in women. Methods We conducted a comprehensive search of peer-reviewed and grey literature for publications of randomised controlled trials available by September 2012. We screened search outputs, selected studies, assessed risk of bias, and extracted data in duplicate; resolving differences by discussion and consensus. Results We identified 13 eligible trials that compared vaginal microbicides to placebo. These studies enrolled 35,905 sexually active HIV-negative women between 1996 and 2011; in Benin, Cameroon, Cote d’Ivoire, Ghana, Kenya, Malawi, Nigeria, South Africa, Tanzania, Uganda, Zambia, Zimbabwe, India, Thailand, and the United States of America. A small trial of 889 women found that tenofovir (a nucleotide reverse transcriptase inhibitor significantly reduces the risk of HIV acquisition (risk ratio [RR] 0.63, 95% confidence intervals [CI] 0.43 to 0.93. Effectiveness data are not yet available from follow-up tenofovir trials being conducted in South Africa, Uganda, and Zimbabwe (1 trial and multiple sites in South Africa (1 trial. We found no evidence of a significant effect for nonoxynol-9 (5 trials, cellulose sulphate (2 trials, SAVVY (2 trials, Carraguard (1 trial, PRO 2000 (2 trials, and BufferGel (1 trial microbicides. The pooled RR for the effect of current experimental vaginal microbicides on HIV acquisition in women was 0.97, 95%CI 0.87 to 1.08. Although study results were homogeneous across the different drug classes (heterogeneity P�

Vaginal microbicides save money: a model of cost-effectiveness in South Africa and the USA.

Science.gov (United States)

Verguet, S; Walsh, J A

2010-06-01

To determine the hypothetical cost-effectiveness of vaginal microbicides preventing male to female HIV transmission. A mathematical epidemiological and cost-effectiveness model using data from South Africa and the USA was used. The prospective 1-year-long intervention targeted a general population of women in a city of 1,000,000 inhabitants in two very different epidemiological settings, South Africa with a male HIV prevalence of 18.80% and the USA with a male HIV prevalence of 0.72%. The base case scenario assumes a microbicide effective at 55%, used in 30% of sexual episodes at a retail price for the public sector in South Africa of US$0.51 per use and in the USA of US$2.23 per use. In South Africa, over 1 year, the intervention would prevent 1908 infections, save US$6712 per infection averted as compared with antiretroviral treatment. In the USA, it would be more costly: over 1 year, the intervention would prevent 21 infections, amounting to a net cost per infection averted of US$405,077. However, in the setting of Washington DC, with a higher HIV prevalence, the same intervention would prevent 93 infections and save US$91,176 per infection averted. Sensitivity analyses were conducted and even a microbicide with a low effectiveness of 30% would still save healthcare costs in South Africa. A microbicide intervention is likely to be very cost-effective in a country undergoing a high-level generalised epidemic such as South Africa, but is unlikely to be cost-effective in a developed country presenting epidemiological features similar to the USA unless the male HIV prevalence exceeds 2.4%.

In vitro profiling of the vaginal permeation potential of anti-HIV microbicides and the influence of formulation excipients.

Science.gov (United States)

Grammen, Carolien; Augustijns, Patrick; Brouwers, Joachim

2012-11-01

In the search for an effective anti-HIV microbicidal gel, limited drug penetration into the vaginal submucosa is a possible reason for failed protection against HIV transmission. To address this issue in early development, we here describe a simple in vitro strategy to predict the tissue permeation potential of vaginally applied drugs, based on solubility, permeability and flux assessment. We demonstrated this approach for four model microbicides (tenofovir, darunavir, saquinavir mesylate and dapivirine) and additionally examined the influence of formulation excipients on the permeation potential. When formulated in an aqueous-based HEC gel, high flux values across an HEC-1A cell layer were reached by tenofovir, as a result of its high aqueous solubility. In contrast, saquinavir and dapivirine fluxes remained low due to poor permeability and solubility, respectively. These low fluxes suggest limited in vivo tissue penetration, possibly leading to lack of efficacy. Dapivirine fluxes, however, could be enhanced up to 30-fold, by including formulation excipients such as polyethylene glycol 1000 (20%) or cyclodextrins (5%) in the HEC gels. Alternative formulations, i.e. emulsions or silicone elastomer gels, were less effective in flux enhancement compared to cyclodextrin-HEC gels. In conclusion, implementing the proposed solubility and permeability profiling in early microbicide development may contribute to the successful selection of promising microbicide candidates and appropriate formulations. Copyright © 2012 Elsevier B.V. All rights reserved.

Acceptability of microbicidal vaginal rings and oral pre-exposure prophylaxis for HIV prevention among female sex workers in a high-prevalence US city.

Science.gov (United States)

Peitzmeier, Sarah M; Tomko, Catherine; Wingo, Erin; Sawyer, Anne; Sherman, Susan G; Glass, Nancy; Beyrer, Chris; Decker, Michele R

2017-11-01

Biomedical HIV prevention tools including oral pre-exposure prophylaxis (PrEP) and vaginal microbicidal rings hold unique value for high-risk women who may have limited capacity for condom negotiation, including the key populations of sex workers and drug users. Commercial sex is a PrEP indicator in CDC guidelines, yet little is known about female sex workers' (FSWs) knowledge of and attitudes toward PrEP or the recently developed monthly vaginal microbicide rings. We describe knowledge and attitudes toward PrEP and microbicide rings in a sample of 60 mostly drug-using FSWs in Baltimore, Maryland, a high HIV-prevalence US city. Just 33% had heard of PrEP, but 65% were interested in taking daily oral PrEP and 76% were interested in a microbicide vaginal ring; 87% were interested in at least one of the two methods. Results suggest method mix will be important as biomedical tools for HIV prophylaxis are implemented and scaled up in this population, as 12% were interested in PrEP but not vaginal rings, while 19% were interested in vaginal rings but not in PrEP. Self-efficacy for daily oral adherence was high (79%) and 78% were interested in using PrEP even if condoms were still necessary. Women who had experienced recent client-perpetrated violence were significantly more interested in PrEP (86% vs 53%, p = 0.009) and microbicidal rings (91% vs 65%, p = 0.028) than women who had not recently experienced violence. No differences were observed by demographics nor HIV risk behaviors, suggesting broad potential interest in daily PrEP and monthly-use vaginal microbicides in this high-risk population.

Acute stress reduces wound-induced activation of microbicidal potential of ex vivo isolated human monocyte-derived macrophages.

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Ulrike Kuebler

Full Text Available BACKGROUND: Psychological stress delays wound healing but the precise underlying mechanisms are unclear. Macrophages play an important role in wound healing, in particular by killing microbes. We hypothesized that (a acute psychological stress reduces wound-induced activation of microbicidal potential of human monocyte-derived macrophages (HMDM, and (b that these reductions are modulated by stress hormone release. METHODS: Fourty-one healthy men (mean age 35 ± 13 years were randomly assigned to either a stress or stress-control group. While the stress group underwent a standardized short-term psychological stress task after catheter-induced wound infliction, stress-controls did not. Catheter insertion was controlled. Assessing the microbicidal potential, we investigated PMA-activated superoxide anion production by HMDM immediately before and 1, 10 and 60 min after stress/rest. Moreover, plasma norepinephrine and epinephrine and salivary cortisol were repeatedly measured. In subsequent in vitro studies, whole blood was incubated with norepinephrine in the presence or absence of phentolamine (norepinephrine blocker before assessing HMDM microbicidal potential. RESULTS: Compared with stress-controls, HMDM of the stressed subjects displayed decreased superoxide anion-responses after stress (p's <.05. Higher plasma norepinephrine levels statistically mediated lower amounts of superoxide anion-responses (indirect effect 95% CI: 4.14-44.72. Norepinephrine-treated HMDM showed reduced superoxide anion-production (p<.001. This effect was blocked by prior incubation with phentolamine. CONCLUSIONS: Our results suggest that acute psychological stress reduces wound-induced activation of microbicidal potential of HMDM and that this reduction is mediated by norepinephrine. This might have implications for stress-induced impairment in wound healing.

K-maps: a vehicle to an optimal solution in combinational logic ...

African Journals Online (AJOL)

K-maps: a vehicle to an optimal solution in combinational logic design problems using digital multiplexers. ... Abstract. Application of Karnaugh maps (K-Maps) for the design of combinational logic circuits and sequential logic circuits is a subject that has been widely discussed. However, the use of K-Maps in the design of ...

The economic efficiency of allowing longer combination vehicles in Texas.

Science.gov (United States)

2011-08-01

This paper shows the economic efficiency of allowing longer combination vehicles in Texas. First, an : overview of the truck size and weight policies is explained, with an emphasis on those that affect : Texas. Next, LCV operations in other countries...

Vehicle Classification and Speed Estimation Using Combined Passive Infrared/Ultrasonic Sensors

KAUST Repository

Odat, Enas M.

2017-09-18

In this paper, a new sensing device that can simultaneously monitor traffic congestion and urban flash floods is presented. This sensing device is based on the combination of passive infrared sensors (PIRs) and ultrasonic rangefinder, and is used for real-time vehicle detection, classification, and speed estimation in the context of wireless sensor networks. This framework relies on dynamic Bayesian Networks to fuse heterogeneous data both spatially and temporally for vehicle detection. To estimate the speed of the incoming vehicles, we first use cross correlation and wavelet transform-based methods to estimate the time delay between the signals of different sensors. We then propose a calibration and self-correction model based on Bayesian Networks to make a joint inference by all sensors about the speed and the length of the detected vehicle. Furthermore, we use the measurements of the ultrasonic and the PIR sensors to perform vehicle classification. Validation data (using an experimental dual infrared and ultrasonic traffic sensor) show a 99% accuracy in vehicle detection, a mean error of 5 kph in vehicle speed estimation, a mean error of 0.7m in vehicle length estimation, and a high accuracy in vehicle classification. Finally, we discuss the computational performance of the algorithm, and show that this framework can be implemented on low-power computational devices within a wireless sensor network setting. Such decentralized processing greatly improves the energy consumption of the system and minimizes bandwidth usage.

Microbicide excipients can greatly increase susceptibility to genital herpes transmission in the mouse

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Sun Mianmian

2010-11-01

Full Text Available Abstract Background Several active ingredients proposed as vaginal microbicides have been shown paradoxically to increase susceptibility to infection in mouse genital herpes (HSV-2 vaginal susceptibility models and in clinical trials. In addition, "inactive ingredients" (or excipients used in topical products to formulate and deliver the active ingredient might also cause epithelial toxicities that increase viral susceptibility. However, excipients have not previously been tested in susceptibility models. Methods Excipients commonly used in topical products were formulated in a non-toxic vehicle (the "HEC universal placebo", or other formulations as specified. Twelve hours after exposure to the excipient or a control treatment, mice were challenged with a vaginal dose of HSV-2, and three days later were assessed for infection by vaginal lavage culture to assess susceptibility. Results The following excipients markedly increased susceptibility to HSV-2 after a single exposure: 5% glycerol monolaurate (GML formulated in K-Y® Warming Jelly, 5% GML as a colloidal suspension in phosphate buffered saline, K-Y Warming Jelly alone, and both of its humectant/solvent ingredients (neat propylene glycol and neat PEG-8. For excipients formulated in the HEC vehicle, 30% glycerin significantly increased susceptibility, and a trend toward increased HSV-2 susceptibility was observed after 10% glycerin, and 0.1% disodium EDTA, but not after 0.0186% disodium EDTA. The following excipients did not increase susceptibility: 10% propylene glycol, 0.18%, methylparaben plus 0.02% propylparaben, and 1% benzyl alcohol. Conclusions As reported with other surfactants, the surfactant/emulsifier GML markedly increased susceptibility to HSV-2. Glycerin at 30% significantly increased susceptibility, and, undiluted propylene glycol and PEG-8 greatly increased susceptibility.

Rational design of HIV vaccine and microbicides: report of the EUROPRISE annual conference

NARCIS (Netherlands)

Wahren, Britta; Biswas, Priscilla; Borggren, Marie; Coleman, Adam; Da Costa, Kelly; de Haes, Winni; Dieltjens, Tessa; Dispinseri, Stefania; Grupping, Katrijn; Hallengärd, David; Hornig, Julia; Klein, Katja; Mainetti, Lara; Palma, Paolo; Reudelsterz, Marc; Seifried, Janna; Selhorst, Philippe; Sköld, Annette; Uchtenhagen, Hannes; van Gils, Marit J.; Weber, Caroline; Shattock, Robin; Scarlatti, Gabriella

2010-01-01

EUROPRISE is a Network of Excellence sponsored from 2007 to 2011 by the European Commission within the 6th Framework Program. The Network encompasses a wide portfolio of activities ranging from an integrated research program in the field of HIV vaccines and microbicides to training, dissemination

Vaginal pH and microbicidal lactic acid when lactobacilli dominate the microbiota.

Science.gov (United States)

O'Hanlon, Deirdre E; Moench, Thomas R; Cone, Richard A

2013-01-01

Lactic acid at sufficiently acidic pH is a potent microbicide, and lactic acid produced by vaginal lactobacilli may help protect against reproductive tract infections. However, previous observations likely underestimated healthy vaginal acidity and total lactate concentration since they failed to exclude women without a lactobacillus-dominated vaginal microbiota, and also did not account for the high carbon dioxide, low oxygen environment of the vagina. Fifty-six women with low (0-3) Nugent scores (indicating a lactobacillus-dominated vaginal microbiota) and no symptoms of reproductive tract disease or infection, provided a total of 64 cervicovaginal fluid samples using a collection method that avoided the need for sample dilution and rigorously minimized aerobic exposure. The pH of samples was measured by microelectrode immediately after collection and under a physiological vaginal concentration of CO2. Commercial enzymatic assays of total lactate and total acetate concentrations were validated for use in CVF, and compared to the more usual HPLC method. The average pH of the CVF samples was 3.5 ± 0.3 (mean ± SD), range 2.8-4.2, and the average total lactate was 1.0% ± 0.2% w/v; this is a five-fold higher average hydrogen ion concentration (lower pH) and a fivefold higher total lactate concentration than in the prior literature. The microbicidal form of lactic acid (protonated lactic acid) was therefore eleven-fold more concentrated, and a markedly more potent microbicide, than indicated by prior research. This suggests that when lactobacilli dominate the vaginal microbiota, women have significantly more lactic acid-mediated protection against infections than currently believed. Our results invite further evaluations of the prophylactic and therapeutic actions of vaginal lactic acid, whether provided in situ by endogenous lactobacilli, by probiotic lactobacilli, or by products that reinforce vaginal lactic acid.

A Multiple siRNA-Based Anti-HIV/SHIV Microbicide Shows Protection in Both In Vitro and In Vivo Models.

Directory of Open Access Journals (Sweden)

Sandhya Boyapalle

Full Text Available Human immunodeficiency virus (HIV types 1 and 2 (HIV-1 and HIV-2 are the etiologic agents of AIDS. Most HIV-1 infected individuals worldwide are women, who acquire HIV infections during sexual contact. Blocking HIV mucosal transmission and local spread in the female lower genital tract is important in preventing infection and ultimately eliminating the pandemic. Microbicides work by destroying the microbes or preventing them from establishing an infection. Thus, a number of different types of microbicides are under investigation, however, the lack of their solubility and bioavailability, and toxicity has been major hurdles. Herein, we report the development of multifunctional chitosan-lipid nanocomplexes that can effectively deliver plasmids encoding siRNA(s as microbicides without adverse effects and provide significant protection against HIV in both in vitro and in vivo models. Chitosan or chitosan-lipid (chlipid was complexed with a cocktail of plasmids encoding HIV-1-specific siRNAs (psiRNAs and evaluated for their efficacy in HEK-293 cells, PBMCs derived from nonhuman primates, 3-dimensional human vaginal ectocervical tissue (3D-VEC model and also in non-human primate model. Moreover, prophylactic administration of the chlipid to deliver a psiRNA cocktail intravaginally with a cream formulation in a non-human primate model showed substantial reduction of SHIV (simian/human immunodeficiency virus SF162 viral titers. Taken together, these studies demonstrate the potential of chlipid-siRNA nanocomplexes as a potential genetic microbicide against HIV infections.

Will dapivirine redeem the promises of anti-HIV microbicides? Overview of product design and clinical testing.

Science.gov (United States)

das Neves, José; Martins, João Pedro; Sarmento, Bruno

2016-08-01

Microbicides are being developed in order to prevent sexual transmission of HIV. Dapivirine, a non-nucleoside reverse transcriptase inhibitor, is one of the leading drug candidates in the field, currently being tested in various dosage forms, namely vaginal rings, gels, and films. In particular, a ring allowing sustained drug release for 1month is in an advanced stage of clinical testing. Two parallel phase III clinical trials are underway in sub-Saharan Africa and results are expected to be released in early 2016. This article overviews the development of dapivirine and its multiple products as potential microbicides, with particular emphasis being placed on clinical evaluation. Also, critical aspects regarding regulatory approval, manufacturing, distribution, and access are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Mathematical model of microbicidal flow dynamics and optimization of rheological properties for intra-vaginal drug delivery: Role of tissue mechanics and fluid rheology.

Science.gov (United States)

Anwar, Md Rajib; Camarda, Kyle V; Kieweg, Sarah L

2015-06-25

Topically applied microbicide gels can provide a self-administered and effective strategy to prevent sexually transmitted infections (STIs). We have investigated the interplay between vaginal tissue elasticity and the yield-stress of non-Newtonian fluids during microbicide deployment. We have developed a mathematical model of tissue deformation driven spreading of microbicidal gels based on thin film lubrication approximation and demonstrated the effect of tissue elasticity and fluid yield-stress on the spreading dynamics. Our results show that both elasticity of tissue and yield-stress rheology of gel are strong determinants of the coating behavior. An optimization framework has been demonstrated which leverages the flow dynamics of yield-stress fluid during deployment to maximize retention while reaching target coating length for a given tissue elasticity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Preclinical assessment of HIV vaccines and microbicides by repeated low-dose virus challenges.

Directory of Open Access Journals (Sweden)

Roland R Regoes

2005-08-01

Full Text Available Trials in macaque models play an essential role in the evaluation of biomedical interventions that aim to prevent HIV infection, such as vaccines, microbicides, and systemic chemoprophylaxis. These trials are usually conducted with very high virus challenge doses that result in infection with certainty. However, these high challenge doses do not realistically reflect the low probability of HIV transmission in humans, and thus may rule out preventive interventions that could protect against "real life" exposures. The belief that experiments involving realistically low challenge doses require large numbers of animals has so far prevented the development of alternatives to using high challenge doses.Using statistical power analysis, we investigate how many animals would be needed to conduct preclinical trials using low virus challenge doses. We show that experimental designs in which animals are repeatedly challenged with low doses do not require unfeasibly large numbers of animals to assess vaccine or microbicide success.Preclinical trials using repeated low-dose challenges represent a promising alternative approach to identify potential preventive interventions.

[Effect on the microbicidal efficacy of formaldehyde, glutardialdehyde, peracetic acid, chloramine T (N-chloro-4-toluenesulfonamide), m-cresol, ethanol and benzyldimethyldodecacylammonium bromide by blood (model experiments for chemical disinfection of instruments)].

Science.gov (United States)

Spicher, G; Peters, J

1998-02-01

In a preceding paper (Zbl. Hyg. 191 [1991] 457-477) we reported on the dependence of the microbicidal efficacy of active agents of the disinfection of instruments on the amount of coagulated blood adhering to the instruments. In the present investigation, we were interested in the dependence of the microbicidal effects on the amount of blood in the solutions of the active agents. Test areas of 2 cm2 were contaminated with 50 and 100 microliters coagulating blood, respectively, containing cells of Staphylococcus aureus as test germ. The solutions of the microbicidal agents were contaminated with heparinized blood up to a concentration of 4% immediately before starting the disinfection and 24 hours before, respectively. After a period of action lasting 1 hour at 20 degrees C, the relative number of test germs capable of multiplying (N/N0) was determined. The concentration of the microbicidal substances reducing the relative number of test germs capable to multiply to 10(-4) served for estimating the dependence of the microbicidal efficacy of the agents on the blood content of the solutions. The experimental results depended on the thickness of the layer of coagulated blood. The dependence of the efficacy of the microbicidal substances on the blood content of the solutions was the higher the thinner the blood layer was. At a thickness of the layer of the coagulated blood of 0.25 mm, a blood content of the solution of 4%, and applying it immediately after adding the blood, the concentration of glutardialdehyde had to be 1.6 times that without blood to reach the same microbicidal efficacy. When applying the solution 24 hours after adding the blood, the concentration of glutardialdehyde had to be 4.2 times that without blood. The quaternary ammonium compound reacted faster with the blood than did glutardialdehyde; the respective factors were 2.6 and 4.5. The concentration factors of chloramine T were 3.3 and 3.8. Under the conditions of the test, peracetic acid exhibited

User-identified gel characteristics: a qualitative exploration of perceived product efficacy of topical vaginal microbicides.

Science.gov (United States)

Morrow, Kathleen M; Underhill, Kristen; van den Berg, Jacob J; Vargas, Sara; Rosen, Rochelle K; Katz, David F

2014-10-01

Research has demonstrated that certain vaginal gel products--microbicides containing antiretroviral drugs--may reduce HIV infection risk among women. But for vaginal gels to avert HIV and other sexually transmitted infections (STIs), at-risk women must be willing to use them as directed. These products must therefore be "acceptable" to women and an important component of acceptability is users' perception that the product will work to prevent infection. We sought to understand how women's perceptions of vaginal gel properties may shape their understanding of product efficacy for HIV and STI prevention. Sixteen women completed two in-depth qualitative interviews (k = 32) to identify the range and types of sensory perceptions they experienced when using two vaginal gels. We identified emergent themes and linkages between users' sensory perceptions and their beliefs about product efficacy. Users' predictions about product efficacy for preventing infection corresponded to measurable physical properties, including gel volume, location in the vagina, coating behavior, sensation of the gel in the vagina, leakage, and gel changes during coital acts. Although the women described similar sensory experiences (e.g., gel leaked from the vagina), they interpreted these experiences to have varying implications for product efficacy (e.g., leakage was predicted to increase or decrease efficacy). To improve microbicide acceptability, gel developers should investigate and deliberately incorporate properties that influence users' perceptions of efficacy. When a microbicide is approved for use, providers should educate users to anticipate and understand their sensory experiences; improving users' experience can maximize adherence and product effectiveness.

A Combined Solar Electric and Storable Chemical Propulsion Vehicle for Piloted Mars Missions

Science.gov (United States)

Mercer, Carolyn R.; Oleson, Steven R.; Drake, Bret G.

2014-01-01

The Mars Design Reference Architecture (DRA) 5.0 explored a piloted Mars mission in the 2030 timeframe, focusing on architecture and technology choices. The DRA 5.0 focused on nuclear thermal and cryogenic chemical propulsion system options for the mission. Follow-on work explored both nuclear and solar electric options. One enticing option that was found in a NASA Collaborative Modeling for Parametric Assessment of Space Systems (COMPASS) design study used a combination of a 1-MW-class solar electric propulsion (SEP) system combined with storable chemical systems derived from the planned Orion crew vehicle. It was found that by using each propulsion system at the appropriate phase of the mission, the entire SEP stage and habitat could be placed into orbit with just two planned Space Launch System (SLS) heavy lift launch vehicles assuming the crew would meet up at the Earth-Moon (E-M) L2 point on a separate heavy-lift launch. These appropriate phases use high-thrust chemical propulsion only in gravity wells when the vehicle is piloted and solar electric propulsion for every other phase. Thus the SEP system performs the spiral of the unmanned vehicle from low Earth orbit (LEO) to E-M L2 where the vehicle meets up with the multi-purpose crew vehicle. From here SEP is used to place the vehicle on a trajectory to Mars. With SEP providing a large portion of the required capture and departure changes in velocity (delta V) at Mars, the delta V provided by the chemical propulsion is reduced by a factor of five from what would be needed with chemical propulsion alone at Mars. This trajectory also allows the SEP and habitat vehicle to arrive in the highly elliptic 1-sol parking orbit compatible with envisioned Mars landing concepts. This paper explores mission options using between SEP and chemical propulsion, the design of the SEP system including the solar array and electric propulsion systems, and packaging in the SLS shroud. Design trades of stay time, power level

Drug transporter gene expression in human colorectal tissue and cell lines: modulation with antiretrovirals for microbicide optimization.

Science.gov (United States)

Mukhopadhya, Indrani; Murray, Graeme I; Berry, Susan; Thomson, John; Frank, Bruce; Gwozdz, Garry; Ekeruche-Makinde, Julia; Shattock, Robin; Kelly, Charles; Iannelli, Francesco; Pozzi, Gianni; El-Omar, Emad M; Hold, Georgina L; Hijazi, Karolin

2016-02-01

The objectives of this study were to comprehensively assess mRNA expression of 84 drug transporters in human colorectal biopsies and six representative cell lines, and to investigate the alteration of drug transporter gene expression after exposure to three candidate microbicidal antiretroviral (ARV) drugs (tenofovir, darunavir and dapivirine) in the colorectal epithelium. The outcome of the objectives informs development of optimal ARV-based microbicidal formulations for prevention of HIV-1 infection. Drug transporter mRNA expression was quantified from colorectal biopsies and cell lines by quantitative real-time PCR. Relative mRNA expression was quantified in Caco-2 cells and colorectal explants after induction with ARVs. Data were analysed using Pearson's product moment correlation (r), hierarchical clustering and principal component analysis (PCA). Expression of 58 of the 84 transporters was documented in colorectal biopsies, with genes for CNT2, P-glycoprotein (P-gp) and MRP3 showing the highest expression. No difference was noted between individual subjects when analysed by age, gender or anatomical site (rectum or recto-sigmoid) (r = 0.95-0.99). High expression of P-gp and CNT2 proteins was confirmed by immunohistochemical staining. Similarity between colorectal tissue and cell-line drug transporter gene expression was variable (r = 0.64-0.84). PCA showed distinct clustering of human colorectal biopsy samples, with the Caco-2 cells defined as the best surrogate system. Induction of Caco-2 cell lines with ARV drugs suggests that darunavir-based microbicides incorporating tenofovir may result in drug-drug interactions likely to affect distribution of individual drugs to sub-epithelial target cells. These findings will help optimize complex formulations of rectal microbicides to realize their full potential as an effective approach for pre-exposure prophylaxis against HIV-1 infection. © The Author 2015. Published by Oxford University Press on behalf of the

Punica granatum (Pomegranate juice provides an HIV-1 entry inhibitor and candidate topical microbicide

Directory of Open Access Journals (Sweden)

Li Yun-Yao

2004-10-01

Full Text Available Abstract Background For ≈ 24 years the AIDS pandemic has claimed ≈ 30 million lives, causing ≈ 14,000 new HIV-1 infections daily worldwide in 2003. About 80% of infections occur by heterosexual transmission. In the absence of vaccines, topical microbicides, expected to block virus transmission, offer hope for controlling the pandemic. Antiretroviral chemotherapeutics have decreased AIDS mortality in industrialized countries, but only minimally in developing countries. To prevent an analogous dichotomy, microbicides should be: acceptable; accessible; affordable; and accelerative in transition from development to marketing. Already marketed pharmaceutical excipients or foods, with established safety records and adequate anti-HIV-1 activity, may provide this option. Methods Fruit juices were screened for inhibitory activity against HIV-1 IIIB using CD4 and CXCR4 as cell receptors. The best juice was tested for inhibition of: (1 infection by HIV-1 BaL, utilizing CCR5 as the cellular coreceptor; and (2 binding of gp120 IIIB and gp120 BaL, respectively, to CXCR4 and CCR5. To remove most colored juice components, the adsorption of the effective ingredient(s to dispersible excipients and other foods was investigated. A selected complex was assayed for inhibition of infection by primary HIV-1 isolates. Results HIV-1 entry inhibitors from pomegranate juice adsorb onto corn starch. The resulting complex blocks virus binding to CD4 and CXCR4/CCR5 and inhibits infection by primary virus clades A to G and group O. Conclusion These results suggest the possibility of producing an anti-HIV-1 microbicide from inexpensive, widely available sources, whose safety has been established throughout centuries, provided that its quality is adequately standardized and monitored.

Object-based detection of vehicles using combined optical and elevation data

Science.gov (United States)

Schilling, Hendrik; Bulatov, Dimitri; Middelmann, Wolfgang

2018-02-01

The detection of vehicles is an important and challenging topic that is relevant for many applications. In this work, we present a workflow that utilizes optical and elevation data to detect vehicles in remotely sensed urban data. This workflow consists of three consecutive stages: candidate identification, classification, and single vehicle extraction. Unlike in most previous approaches, fusion of both data sources is strongly pursued at all stages. While the first stage utilizes the fact that most man-made objects are rectangular in shape, the second and third stages employ machine learning techniques combined with specific features. The stages are designed to handle multiple sensor input, which results in a significant improvement. A detailed evaluation shows the benefits of our workflow, which includes hand-tailored features; even in comparison with classification approaches based on Convolutional Neural Networks, which are state of the art in computer vision, we could obtain a comparable or superior performance (F1 score of 0.96-0.94).

77 FR 70167 - Draft Guidance for Industry on Vaginal Microbicides: Development for the Prevention of Human...

Science.gov (United States)

2012-11-23

...] Draft Guidance for Industry on Vaginal Microbicides: Development for the Prevention of Human...: The Food and Drug Administration (FDA) is announcing the availability of a draft guidance for industry... Drug Information, Center for Drug Evaluation and Research, Food and Drug Administration, 10903 New...

Engineering soya bean seeds as a scalable platform to produce cyanovirin-N, a non-ARV microbicide against HIV.

Science.gov (United States)

O'Keefe, Barry R; Murad, André M; Vianna, Giovanni R; Ramessar, Koreen; Saucedo, Carrie J; Wilson, Jennifer; Buckheit, Karen W; da Cunha, Nicolau B; Araújo, Ana Claudia G; Lacorte, Cristiano C; Madeira, Luisa; McMahon, James B; Rech, Elibio L

2015-09-01

There is an urgent need to provide effective anti-HIV microbicides to resource-poor areas worldwide. Some of the most promising microbicide candidates are biotherapeutics targeting viral entry. To provide biotherapeutics to poorer areas, it is vital to reduce the cost. Here, we report the production of biologically active recombinant cyanovirin-N (rCV-N), an antiviral protein, in genetically engineered soya bean seeds. Pure, biologically active rCV-N was isolated with a yield of 350 μg/g of dry seed weight. The observed amino acid sequence of rCV-N matched the expected sequence of native CV-N, as did the mass of rCV-N (11 009 Da). Purified rCV-N from soya is active in anti-HIV assays with an EC50 of 0.82-2.7 nM (compared to 0.45-1.8 nM for E. coli-produced CV-N). Standard industrial processing of soya bean seeds to harvest soya bean oil does not diminish the antiviral activity of recovered rCV-N, allowing the use of industrial soya bean processing to generate both soya bean oil and a recombinant protein for anti-HIV microbicide development. © 2015 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Australian men’s experiences during a microbicide male tolerance study

Science.gov (United States)

Rosenthal, Susan L.; Holmes, Wendy; Maher, Lisa

2008-01-01

Microbicides currently in development have the potential to provide new options for the prevention of sexually transmitted infections if proven safe and efficacious. We examined the experiences of healthy male volunteers in a male tolerance study in Victoria, Australia in relation to trial participation and product use. Men (N = 36) enrolled in a seven-day, phase 1 clinical safety trial of SPL7013 were interviewed pre and post-use of the gel using a semi-structured interview guide. Interviews were digitally recorded and transcribed verbatim, and transcripts were analysed using a framework approach. All but one man completed the trial. The median age was 34 years (range 22–67 years). Most men had little pre-study knowledge of microbicides and almost all participated for altruistic or personal reasons. Men expressed few concerns about product safety during the trial and indicated trust in the information received through the consent process and from study staff. Three men were non-adherent to the request to be abstinent and an additional two did not refrain from masturbation. Most were positive about the gel, although they described it as “sticky” and found that it stuck to clothes, bed sheets and pubic hair. The type of applicator used was unfamiliar to the men, and some found it “clinical” in appearance. Men are willing to participate in male tolerance studies, often for altruistic reasons. However, counseling about ways to maintain abstinence and further research to inform anticipatory guidance regarding the “sticky” quality of gels, may be important. PMID:19085229

Microbicidal activity of neutrophils is inhibited by isolates from recurrent vaginal candidiasis (RVVC) caused by Candida albicans through fungal thioredoxin reductase.

Science.gov (United States)

Ratti, Bianca Altrão; Godoy, Janine Silva Ribeiro; de Souza Bonfim Mendonça, Patrícia; Bidóia, Danielle Lazarin; Nakamura, Tânia Ueda; Nakamura, Celso Vataru; Lopes Consolaro, Marcia Edilaine; Estivalet Svidzinski, Terezinha Inez; de Oliveira Silva, Sueli

2015-01-01

Vulvovaginal candidiasis (VVC) is characterized by an infection of the vulva and vagina, mainly caused by Candida albicans, a commensal microorganism that inhabits the vaginal, digestive, and respiratory mucosae. Vulvovaginal candidiasis affects approximately 75% of women, and 5% develop the recurrent form (RVVC). The aim of the present study was to evaluate whether neutrophils microbicidal response is triggered when activated with RVVC isolates caused by C. albicans. Our results showed that RVVC isolates induced neutrophil migration but significantly decrease the microbicidal activity of neutrophils, compared with VVC and ASS isolates. The microbicidal activity of neutrophils is highly dependent on the production of reactive oxygen species/reactive nitrogen species (ROS/RNS). However, this isolate induced detoxification of ROS/RNS produced by neutrophils, reflected by the high level of thiol groups and by the oxygen consumption. Therefore, RVVC isolates induced biochemical changes in the inflammatory response triggered by neutrophils, and these effects were mainly related to the detoxification of ROS/RNS through the thioredoxin reductase (TR), a key antioxidant enzyme in fungi. This might be one of the resistance mechanisms triggered by RVVC caused by C. albicans. Copyright © 2014 Elsevier Inc. All rights reserved.

Formulation development of retrocyclin 1 analog RC-101 as an anti-HIV vaginal microbicide product.

Science.gov (United States)

Sassi, A B; Cost, M R; Cole, A L; Cole, A M; Patton, D L; Gupta, P; Rohan, L C

2011-05-01

RC-101 is a synthetic microbicide analog of retrocyclin, which has shown in vitro activity against X4 and R5 HIV-1. In an effort to develop a safe and effective RC-101 vaginal microbicide product, we assessed safety in ex vivo macaque and human models and efficacy using in vitro and ex vivo models. A polyvinyl-alcohol vaginal film containing RC-101 (100 μg/film) was developed. Formulation assessment was conducted by evaluating disintegration, drug content, mechanical properties, and stability. Efficacy was evaluated by in vitro peripheral blood mononuclear cells (PBMC) assay and ex vivo human ectocervical tissue explant model. Ex vivo safety studies were conducted by exposing RC-101 to an excised monkey reproductive tract and excised human ectocervical tissue. RC-101 100 μg films were shown to be safe to human and monkey tissue and effective against HIV-1 in vitro and ex vivo in human ectocervical tissue. The 90% inhibitory concentration (IC90) for RC-101 films at 2,000 μg (IC90=57.5 μM) using an ex vivo model was 10-fold higher than the IC90 observed using an in vitro model (IC90=5.0 μM). RC-101 films were stable for 1 month at 25°C, with in vitro bioactivity maintained for up to 6 months. RC-101 was developed in a quick-dissolve film formulation that was shown to be safe in an ex vivo model and effective in in vitro and ex vivo models. RC-101 film formulations were shown to maintain bioactivity for a period of 6 months. Findings from the present study contribute to the development of a safe and effective topical microbicide product.

A silicone elastomer vaginal ring for HIV prevention containing two microbicides with different mechanisms of action.

Science.gov (United States)

Fetherston, Susan M; Boyd, Peter; McCoy, Clare F; McBride, Marcella C; Edwards, Karen-Leigh; Ampofo, Stephen; Malcolm, R Karl

2013-02-14

Vaginal rings are currently being developed for the long-term (at least 30 days) continuous delivery of microbicides against human immunodeficiency virus (HIV). Research to date has mostly focused on devices containing a single antiretroviral compound, exemplified by the 25mg dapivirine ring currently being evaluated in a Phase III clinical study. However, there is a strong clinical rationale for combining antiretrovirals with different mechanisms of action in a bid to increase breadth of protection and limit the emergence of resistant strains. Here we report the development of a combination antiretroviral silicone elastomer matrix-type vaginal ring for simultaneous controlled release of dapivirine, a non-nucleoside reverse transcriptase inhibitor, and maraviroc, a CCR5-targeted HIV-1 entry inhibitor. Vaginal rings loaded with 25mg dapivirine and various quantities of maraviroc (50-400mg) were manufactured and in vitro release assessed. The 25mg dapivirine and 100mg maraviroc formulation was selected for further study. A 24-month pharmaceutical stability evaluation was conducted, indicating good product stability in terms of in vitro release, content assay, mechanical properties and related substances. This combination ring product has now progressed to Phase I clinical testing. Copyright © 2012 Elsevier B.V. All rights reserved.

On-demand microbicide products: design matters.

Science.gov (United States)

Patel, Sravan Kumar; Rohan, Lisa Cencia

2017-12-01

Sexual intercourse (vaginal and anal) is the predominant mode of human immunodeficiency virus (HIV) transmission. Topical microbicides used in an on-demand format (i.e., immediately before or after sex) can be part of an effective tool kit utilized to prevent sexual transmission of HIV. The effectiveness of prevention products is positively correlated with adherence, which is likely to depend on user acceptability of the product. The development of an efficacious and acceptable product is therefore paramount for the success of an on-demand product. Acceptability of on-demand products (e.g., gels, films, and tablets) and their attributes is influenced by a multitude of user-specific factors that span behavioral, lifestyle, socio-economic, and cultural aspects. In addition, physicochemical properties of the drug, anatomical and physiological aspects of anorectal and vaginal compartments, issues relating to large-scale production, and cost can impact product development. These factors together with user preferences determine the design space of an effective, acceptable, and feasible on-demand product. In this review, we summarize the interacting factors that together determine product choice and its target product profile.

Preformulation and stability in biological fluids of the retrocyclin RC-101, a potential anti-HIV topical microbicide

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Conrads Thomas P

2011-07-01

Full Text Available Abstract Background RC-101, a cationic peptide retrocyclin analog, has in vitro activity against HIV-1. Peptide drugs are commonly prone to conformational changes, oxidation and hydrolysis when exposed to excipients in a formulation or biological fluids in the body, this can affect product efficacy. We aimed to investigate RC-101 stability under several conditions including the presence of human vaginal fluids (HVF, enabling the efficient design of a safe and effective microbicide product. Stability studies (temperature, pH, and oxidation were performed by HPLC, Circular Dichroism, and Mass Spectrometry (LC-MS/MS. Additionally, the effect of HVF on formulated RC-101 was evaluated with fluids collected from healthy volunteers, or from subjects with bacterial vaginosis (BV. RC-101 was monitored by LC-MS/MS for up to 72 h. Results RC-101 was stable at pH 3, 4, and 7, at 25 and 37°C. High concentrations of hydrogen peroxide resulted in less than 10% RC-101 reduction over 24 h. RC-101 was detected 48 h after incubation with normal HVF; however, not following incubation with HVF from BV subjects. Conclusions Our results emphasize the importance of preformulation evaluations and highlight the impact of HVF on microbicide product stability and efficacy. RC-101 was stable in normal HVF for at least 48 h, indicating that it is a promising candidate for microbicide product development. However, RC-101 stability appears compromised in individuals with BV, requiring more advanced formulation strategies for stabilization in this environment.

Multidisciplinary design of a rocket-based combined cycle SSTO launch vehicle using Taguchi methods

Science.gov (United States)

Olds, John R.; Walberg, Gerald D.

1993-01-01

Results are presented from the optimization process of a winged-cone configuration SSTO launch vehicle that employs a rocket-based ejector/ramjet/scramjet/rocket operational mode variable-cycle engine. The Taguchi multidisciplinary parametric-design method was used to evaluate the effects of simultaneously changing a total of eight design variables, rather than changing them one at a time as in conventional tradeoff studies. A combination of design variables was in this way identified which yields very attractive vehicle dry and gross weights.

Formulation and characterization of polymeric films containing combinations of antiretrovirals (ARVs) for HIV prevention.

Science.gov (United States)

Akil, Ayman; Agashe, Hrushikesh; Dezzutti, Charlene S; Moncla, Bernard J; Hillier, Sharon L; Devlin, Brid; Shi, Yuan; Uranker, Kevin; Rohan, Lisa Cencia

2015-02-01

To develop polymeric films containing dual combinations of anti-HIV drug candidate tenofovir, maraviroc and dapivirine for vaginal application as topical microbicides. A solvent casting method was used to manufacture the films. Solid phase solubility was used to identify potential polymers for use in the film formulation. Physical and chemical properties (such as water content, puncture strength and in vitro release) and product stability were determined. The bioactivity of the film products against HIV was assessed using the TZM-bl assay and a cervical explant model. Polymers identified from the solid phase solubility study maintained tenofovir and maraviroc in an amorphous state and prevented drug crystallization. Three combination film products were developed using cellulose polymers and polyvinyl alcohol. The residual water content in all films was 50% of film drug content within 30 min. Stability testing confirmed that the combination film products were stable for 12 months at ambient temperature and 6 months under stressed conditions. Antiviral activity was confirmed in TZM-bl and cervical explant models. Polymeric films can be used as a stable dosage form for the delivery of antiretroviral combinations as microbicides.

Intravaginal insertion in KwaZulu Natal: sexual practices and preferences in the context of microbicide gel use

NARCIS (Netherlands)

Gafos, M.; Mzimela, M.; Sukazi, S.; Pool, R.; Montgomery, C.; Elford, J.

2010-01-01

Intravaginal insertion is often associated with the concept of ‘dry’ sex. All HIV-prevention microbicides tested to date have been vaginally applied lubricant-based gels. In this paper, we examine whether the use of intravaginal insertions could be in conflict with the introduction of vaginal

Dual extended Kalman filter for combined estimation of vehicle state and road friction

Science.gov (United States)

Zong, Changfu; Hu, Dan; Zheng, Hongyu

2013-03-01

Vehicle state and tire-road adhesion are of great use and importance to vehicle active safety control systems. However, it is always not easy to obtain the information with high accuracy and low expense. Recently, many estimation methods have been put forward to solve such problems, in which Kalman filter becomes one of the most popular techniques. Nevertheless, the use of complicated model always leads to poor real-time estimation while the role of road friction coefficient is often ignored. For the purpose of enhancing the real time performance of the algorithm and pursuing precise estimation of vehicle states, a model-based estimator is proposed to conduct combined estimation of vehicle states and road friction coefficients. The estimator is designed based on a three-DOF vehicle model coupled with the Highway Safety Research Institute(HSRI) tire model; the dual extended Kalman filter (DEKF) technique is employed, which can be regarded as two extended Kalman filters operating and communicating simultaneously. Effectiveness of the estimation is firstly examined by comparing the outputs of the estimator with the responses of the vehicle model in CarSim under three typical road adhesion conditions(high-friction, low-friction, and joint-friction). On this basis, driving simulator experiments are carried out to further investigate the practical application of the estimator. Numerical results from CarSim and driving simulator both demonstrate that the estimator designed is capable of estimating the vehicle states and road friction coefficient with reasonable accuracy. The DEKF-based estimator proposed provides the essential information for the vehicle active control system with low expense and decent precision, and offers the possibility of real car application in future.

The Sheep as a Model of Preclinical Safety and Pharmacokinetic Evaluations of Candidate Microbicides

OpenAIRE

Holt, Jonathon D. S.; Cameron, David; Dias, Nicola; Holding, Jeremy; Muntendam, Alex; Oostebring, Freddy; Dreier, Peter; Rohan, Lisa; Nuttall, Jeremy

2015-01-01

When developing novel microbicide products for the prevention of HIV infection, the preclinical safety program must evaluate not only the active pharmaceutical ingredient but also the product itself. To that end, we applied several relatively standard toxicology study methodologies to female sheep, incorporating an assessment of the pharmacokinetics, safety, tolerability, and local toxicity of a dapivirine-containing human vaginal ring formulation (Dapivirine Vaginal Ring-004). We performed a...

Virucidal activity of the dendrimer microbicide SPL7013 against HIV-1.

Science.gov (United States)

Telwatte, Sushama; Moore, Katie; Johnson, Adam; Tyssen, David; Sterjovski, Jasminka; Aldunate, Muriel; Gorry, Paul R; Ramsland, Paul A; Lewis, Gareth R; Paull, Jeremy R A; Sonza, Secondo; Tachedjian, Gilda

2011-06-01

Topical microbicides for use by women to prevent the transmission of human immunodeficiency virus (HIV) and other sexually transmitted infections are urgently required. Dendrimers are highly branched nanoparticles being developed as microbicides. SPL7013 is a dendrimer with broad-spectrum activity against HIV type I (HIV-1) and -2 (HIV-2), herpes simplex viruses type-1 (HSV-1) and -2 (HSV-2) and human papillomavirus. SPL7013 [3% (w/w)] has been formulated in a mucoadhesive carbopol gel (VivaGel®) for use as a topical microbicide. Previous studies showed that SPL7013 has similar potency against CXCR4-(X4) and CCR5-using (R5) strains of HIV-1 and that it blocks viral entry. However, the ability of SPL7013 to directly inactivate HIV-1 is unknown. We examined whether SPL7013 demonstrates virucidal activity against X4 (NL4.3, MBC200, CMU02 clade EA and 92UG046 clade D), R5 (Ba-L, NB25 and 92RW016 clade A) and dual-tropic (R5X4; MACS1-spln) HIV-1 using a modified HLA-DR viral capture method and by polyethylene glycol precipitation. Evaluation of virion integrity was determined by ultracentrifugation through a sucrose cushion and detection of viral proteins by Western blot analysis. SPL7013 demonstrated potent virucidal activity against X4 and R5X4 strains, although virucidal activity was less potent for the 92UG046 X4 clade D isolate. Where potent virucidal activity was observed, the 50% virucidal concentrations were similar to the 50% effective concentrations previously reported in drug susceptibility assays, indicating that the main mode of action of SPL7013 is by direct viral inactivation for these strains. In contrast, SPL7013 lacked potent virucidal activity against R5 HIV-1 strains. Evaluation of the virucidal mechanism showed that SPL7013-treated NL4.3, 92UG046 and MACS1-spln virions were intact with no significant decrease in gp120 surface protein with respect to p24 capsid content compared to the corresponding untreated virus. These studies demonstrate that SPL

Longer combination vehicles : an estimation of their benefits and public perception of their use.

Science.gov (United States)

2012-03-01

Longer Combination Vehicles (LCVs) are able to carry more freight than conventional single trailer trucks. As a result, these trucks can increase : efficiencies and benefits for freight movements as less fuel and less labor is used per ton of cargo. ...

Curcumin as a potential non-steroidal contraceptive with spermicidal and microbicidal properties.

Science.gov (United States)

Naz, R K; Lough, M L

2014-05-01

Curcumin, a component of the curry powder turmeric, has immense biological properties, including anticancer effects. The objective of this study was to determine if curcumin can provide a novel non-steroidal contraceptive having both spermicidal and microbicidal properties. The effect of curcumin, with and without photosensitization, was examined on human sperm forward motility and growth of several aerobic (n=8) and anaerobic bacteria (n=4) and yeast (n=7) strains implicated in vaginosis, vaginitis, and vaginal infections in women. The effect of various concentrations of curcumin on human sperm and microbes (aerobic and anaerobic bacteria and yeast) was tested. The effect on sperm was examined by counting the sperm forward motility, and on microbes by agar and broth dilutions and colony counting. Each experiment was repeated using different semen specimens, and bacteria and yeast stocks. Curcumin caused a concentration-dependent inhibition of sperm forward motility with a total block at ≥250μM concentration. After photosensitization, the effective concentration to completely block sperm forward motility decreased 25-fold, now requiring only 10μM concentration for total inhibition. Curcumin concentrations between 100 and 500μM completely blocked the growth of all the bacteria and yeast strains tested. After photosensitization, the effective concentration to completely inhibit microbial growth decreased 10-fold for aerobic bacteria and yeast, and 5-fold for anaerobic bacteria. These findings suggest that curcumin can block sperm function and bacteria/yeast growth. It can potentially provide an ideal non-steroidal contraceptive having both spermicidal and microbicidal properties against vaginal infections. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Development of a new formulation combining calcipotriol and betamethasone dipropionate in an ointment vehicle

DEFF Research Database (Denmark)

Simonsen, Lene; Høy, Gert; Didriksen, Erik

2004-01-01

was to develop a formulation which combines calcipotriol and betamethasone dipropionate in a single vehicle hereby achieving optimal delivery of both substances into the skin. As the two substances are incompatible in aqueous and alcoholic medias, different non-aqueous formulations were prepared. Skin permeation...

Update on microbicide research and development-seeking new HIV prevention tools for women

Directory of Open Access Journals (Sweden)

Mertenskoetter T

2011-01-01

Full Text Available Abstract Women and girls are especially vulnerable to HIV infection in sub-Saharan Africa, and in some of those countries, prevalence among young women can be up to 3 times higher than among men of the same age. Effective HIV prevention options for women are clearly needed in this setting. Several ARV-based vaginal microbicides are currently in development for prevention of HIV transmission to women and are discussed here. The concept of pre-exposure prophylaxis for the prevention of HIV transmission to women is introduced.

A Neural Network Combined Inverse Controller for a Two-Rear-Wheel Independently Driven Electric Vehicle

Directory of Open Access Journals (Sweden)

Duo Zhang

2014-07-01

Full Text Available Vehicle active safety control is attracting ever increasing attention in the attempt to improve the stability and the maneuverability of electric vehicles. In this paper, a neural network combined inverse (NNCI controller is proposed, incorporating the merits of left-inversion and right-inversion. As the left-inversion soft-sensor can estimate the sideslip angle, while the right-inversion is utilized to decouple control. Then, the proposed NNCI controller not only linearizes and decouples the original nonlinear system, but also directly obtains immeasurable state feedback in constructing the right-inversion. Hence, the proposed controller is very practical in engineering applications. The proposed system is co-simulated based on the vehicle simulation package CarSim in connection with Matlab/Simulink. The results verify the effectiveness of the proposed control strategy.

Lignosulfonic acid exhibits broadly anti-HIV-1 activity--potential as a microbicide candidate for the prevention of HIV-1 sexual transmission.

Directory of Open Access Journals (Sweden)

Min Qiu

Full Text Available Some secondary metabolites from plants show to have potent inhibitory activities against microbial pathogens, such as human immunodeficiency virus (HIV, herpes simplex virus (HSV, Treponema pallidum, Neisseria gonorrhoeae, etc. Here we report that lignosulfonic acid (LSA, a polymeric lignin derivative, exhibits potent and broad activity against HIV-1 isolates of diverse subtypes including two North America strains and a number of Chinese clinical isolates values ranging from 21.4 to 633 nM. Distinct from other polyanions, LSA functions as an entry inhibitor with multiple targets on viral gp120 as well as on host receptor CD4 and co-receptors CCR5/CXCR4. LSA blocks viral entry as determined by time-of-drug addiction and cell-cell fusion assays. Moreover, LSA inhibits CD4-gp120 interaction by blocking the binding of antibodies specific for CD4-binding sites (CD4bs and for the V3 loop of gp120. Similarly, LSA interacts with CCR5 and CXCR4 via its inhibition of specific anti-CCR5 and anti-CXCR4 antibodies, respectively. Interestingly, the combination of LSA with AZT and Nevirapine exhibits synergism in viral inhibition. For the purpose of microbicide development, LSA displays low in vitro cytotoxicity to human genital tract epithelial cells, does not stimulate NF-κB activation and has no significant up-regulation of IL-1α/β and IL-8 as compared with N-9. Lastly, LSA shows no adverse effect on the epithelial integrity and the junctional protein expression. Taken together, our findings suggest that LSA can be a potential candidate for tropical microbicide.

A Scramjet Compression System for Hypersonic Air Transportation Vehicle Combined Cycle Engines

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Devendra Sen

2018-06-01

Full Text Available This paper proposes a compression system for a scramjet, to be used as part of a combined cycle engine on a hypersonic transport vehicle that can achieve sustained flight at 8 Mach 8. Initially research into scramjet compression system and shock wave interaction was conducted to establish the foundation of the scramjet inlet and isolator sections. A Computational Fluid Dynamics (CFD campaign was conducted, where the shock structure and flow characteristics was analysed between Mach 4.5–8. The compression system of a scramjet is of crucial importance in providing air at suitable Mach number, pressure and temperature to the combustion chamber. The use of turbojet engines in over-under configuration with the scramjet was investigated as well as the study of a combined cycle scramjet-ramjet configuration. It was identified that locating the scramjet in the centre with a rotated ramjet on either side, where its ramps make up the scramjet wall was the most optimal configuration, as it mitigated the effect of the oblique shocks propagating from the scramjet walls into the adjacent ramjet. Furthermore, this meant that the forebody of the vehicle could solely be used as the compression surface by the scramjet. In this paper, the sizing of the scramjet combustion chamber and nozzle were modified to match the flow properties of the oncoming flow with the purpose of producing the most optimum scramjet configuration for the cruise speed of Mach 8. CFD simulations showed that the scramjet inlet did not provide the levels of compression and stagnation pressure recovery initially required. However, it was found that the scramjet provided significantly more thrust than the drag of the aircraft at sustained Mach 8 flight, due to its utilisation of a very aerodynamic vehicle design.

Heavy and Overweight Vehicle Brake Testing: Five-Axle Combination Tractor-Flatbed Final Report

Energy Technology Data Exchange (ETDEWEB)

Lascurain, Mary Beth [ORNL; Capps, Gary J [ORNL; Franzese, Oscar [ORNL

2013-10-01

The Federal Motor Carrier Safety Administration, in coordination with the Federal Highway Administration, sponsored the Heavy and Overweight Vehicle Brake Testing (HOVBT) program in order to provide information about the effect of gross vehicle weight (GVW) on braking performance. Because the Federal Motor Carrier Safety Regulations limit the number of braking system defects that may exist for a vehicle to be allowed to operate on the roadways, the examination of the effect of brake defects on brake performance for increased loads is also relevant. The HOVBT program seeks to provide relevant information to policy makers responsible for establishing load limits, beginning with providing test data for a combination tractor/trailer. This testing was conducted on a five-axle combination vehicle with tractor brakes meeting the Reduced Stopping Distance requirement rulemaking. This report provides a summary of the testing activities, the results of various analyses of the data, and recommendations for future research. Following a complete brake rebuild, instrumentation, and brake burnish, stopping tests were performed from 20 and 40 mph with various brake application pressures (15 psi, 25 psi, 35 psi, 45 psi, 55 psi, and full system pressure). These tests were conducted for various brake conditions at the following GVWs: 60,000, 80,000, 91,000, 97,000, 106,000, and 116,000 lb. The 80,000-lb GVWs included both balanced and unbalanced loads. The condition of the braking system was also varied. To introduce these defects, brakes (none, forward drive axle, or rear trailer axle) were made inoperative. In addition to the stopping tests, performance-based brake tests were conducted for the various loading and brake conditions. Analysis of the stopping test data showed the stopping distance to increase with load (as expected) and also showed that more braking force was generated by the drive axle brakes than the trailer axle brakes. The constant-pressure stopping test data

Modeling of Combined Phenomena Affecting an AUV Stealth Vehicle

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Miroslaw Gerigk

2016-12-01

Full Text Available In the paper some results of research connected with modeling the basic stealth characteristics of an AUV vehicle are presented. First of all a general approach to design of the stealth AUV autonomous underwater vehicles under consideration is introduced. Then the AUV stealth vehicle concept is briefly described. Next a method of modeling of the stealth characteristics is briefly described. As an example of the stealth characteristics investigations some results of modeling the boundary layer and wake are presented. Some remarks regarding the behavior of the AUV stealth vehicle in the submerged conditions are given. The final conclusions are presented.

Polymeric nanoparticles affect the intracellular delivery, antiretroviral activity and cytotoxicity of the microbicide drug candidate dapivirine.

Science.gov (United States)

das Neves, José; Michiels, Johan; Ariën, Kevin K; Vanham, Guido; Amiji, Mansoor; Bahia, Maria Fernanda; Sarmento, Bruno

2012-06-01

To assess the intracellular delivery, antiretroviral activity and cytotoxicity of poly(ε-caprolactone) (PCL) nanoparticles containing the antiretroviral drug dapivirine. Dapivirine-loaded nanoparticles with different surface properties were produced using three surface modifiers: poloxamer 338 NF (PEO), sodium lauryl sulfate (SLS) and cetyl trimethylammonium bromide (CTAB). The ability of nanoparticles to promote intracellular drug delivery was assessed in different cell types relevant for vaginal HIV transmission/microbicide development. Also, antiretroviral activity of nanoparticles was determined in different cell models, as well as their cytotoxicity. Dapivirine-loaded nanoparticles were readily taken up by different cells, with particular kinetics depending on the cell type and nanoparticles, resulting in enhanced intracellular drug delivery in phagocytic cells. Different nanoparticles showed similar or improved antiviral activity compared to free drug. There was a correlation between increased antiviral activity and increased intracellular drug delivery, particularly when cell models were submitted to a single initial short-course treatment. PEO-PCL and SLS-PCL nanoparticles consistently showed higher selectivity index values than free drug, contrasting with high cytotoxicity of CTAB-PCL. These results provide evidence on the potential of PCL nanoparticles to affect in vitro toxicity and activity of dapivirine, depending on surface engineering. Thus, this formulation approach may be a promising strategy for the development of next generation microbicides.

A model predictive control approach combined unscented Kalman filter vehicle state estimation in intelligent vehicle trajectory tracking

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Hongxiao Yu

2015-05-01

Full Text Available Trajectory tracking and state estimation are significant in the motion planning and intelligent vehicle control. This article focuses on the model predictive control approach for the trajectory tracking of the intelligent vehicles and state estimation of the nonlinear vehicle system. The constraints of the system states are considered when applying the model predictive control method to the practical problem, while 4-degree-of-freedom vehicle model and unscented Kalman filter are proposed to estimate the vehicle states. The estimated states of the vehicle are used to provide model predictive control with real-time control and judge vehicle stability. Furthermore, in order to decrease the cost of solving the nonlinear optimization, the linear time-varying model predictive control is used at each time step. The effectiveness of the proposed vehicle state estimation and model predictive control method is tested by driving simulator. The results of simulations and experiments show that great and robust performance is achieved for trajectory tracking and state estimation in different scenarios.

Rectal microbicides: clinically relevant approach to the design of rectal specific placebo formulations

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Dezzutti Charlene

2011-03-01

Full Text Available Abstract Background The objective of this study is to identify the critical formulation parameters controlling distribution and function for the rectal administration of microbicides in humans. Four placebo formulations were designed with a wide range of hydrophilic characteristics (aqueous to lipid and rheological properties (Newtonian, shear thinning, thermal sensitive and thixotropic. Aqueous formulations using typical polymers to control viscosity were iso-osmotic and buffered to pH 7. Lipid formulations were developed from lipid solvent/lipid gelling agent binary mixtures. Testing included pharmaceutical function and stability as well as in vitro and in vivo toxicity. Results The aqueous fluid placebo, based on poloxamer, was fluid at room temperature, thickened and became shear thinning at 37°C. The aqueous gel placebo used carbopol as the gelling agent, was shear thinning at room temperature and showed a typical decrease in viscosity with an increase in temperature. The lipid fluid placebo, myristyl myristate in isopropyl myristate, was relatively thin and temperature independent. The lipid gel placebo, glyceryl stearate and PEG-75 stearate in caprylic/capric triglycerides, was also shear thinning at both room temperature and 37°C but with significant time dependency or thixotropy. All formulations showed no rectal irritation in rabbits and were non-toxic using an ex vivo rectal explant model. Conclusions Four placebo formulations ranging from fluid to gel in aqueous and lipid formats with a range of rheological properties were developed, tested, scaled-up, manufactured under cGMP conditions and enrolled in a formal stability program. Clinical testing of these formulations as placebos will serve as the basis for further microbicide formulation development with drug-containing products.

Preliminary Sizing Completed for Single- Stage-To-Orbit Launch Vehicles Powered By Rocket-Based Combined Cycle Technology

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Roche, Joseph M.

2002-01-01

Single-stage-to-orbit (SSTO) propulsion remains an elusive goal for launch vehicles. The physics of the problem is leading developers to a search for higher propulsion performance than is available with all-rocket power. Rocket-based combined cycle (RBCC) technology provides additional propulsion performance that may enable SSTO flight. Structural efficiency is also a major driving force in enabling SSTO flight. Increases in performance with RBCC propulsion are offset with the added size of the propulsion system. Geometrical considerations must be exploited to minimize the weight. Integration of the propulsion system with the vehicle must be carefully planned such that aeroperformance is not degraded and the air-breathing performance is enhanced. Consequently, the vehicle's structural architecture becomes one with the propulsion system architecture. Geometrical considerations applied to the integrated vehicle lead to low drag and high structural and volumetric efficiency. Sizing of the SSTO launch vehicle (GTX) is itself an elusive task. The weight of the vehicle depends strongly on the propellant required to meet the mission requirements. Changes in propellant requirements result in changes in the size of the vehicle, which in turn, affect the weight of the vehicle and change the propellant requirements. An iterative approach is necessary to size the vehicle to meet the flight requirements. GTX Sizer was developed to do exactly this. The governing geometry was built into a spreadsheet model along with scaling relationships. The scaling laws attempt to maintain structural integrity as the vehicle size is changed. Key aerodynamic relationships are maintained as the vehicle size is changed. The closed weight and center of gravity are displayed graphically on a plot of the synthesized vehicle. In addition, comprehensive tabular data of the subsystem weights and centers of gravity are generated. The model has been verified for accuracy with finite element analysis. The

Safety of a silicone elastomer vaginal ring as potential microbicide delivery method in African women: A Phase 1 randomized trial.

Science.gov (United States)

Nel, Annaléne; Martins, Janine; Bekker, Linda-Gail; Ramjee, Gita; Masenga, Gileard; Rees, Helen; van Niekerk, Neliëtte

2018-01-01

Women in sub-Saharan Africa are in urgent need of female-initiated human immunodeficiency virus (HIV) preventative methods. Vaginal rings are one dosage form in development for delivery of HIV microbicides. However, African women have limited experience with vaginal rings. This Phase I, randomized, crossover trial assessed and compared the safety, acceptability and adherence of a silicone elastomer placebo vaginal ring, intended as a microbicide delivery method, inserted for a 12-week period in healthy, HIV-negative, sexually active women in South Africa and Tanzania. 170 women, aged 18 to 35 years were enrolled with 88 women randomized to Group A, using a placebo vaginal ring for 12 weeks followed by a 12-week safety observation period. 82 women were randomized to Group B and observed for safety first, followed by a placebo vaginal ring for 12 weeks. Safety was assessed by clinical laboratory assessments, pelvic/colposcopy examinations and adverse events. Possible carry-over effect was addressed by ensuring no signs or symptoms of genital irritation at crossover. No safety concerns were identified for any safety variables assessed during the trial. No serious adverse events were reported considered related to the placebo vaginal ring. Vaginal candidiasis was the most common adverse event occurring in 11% of participants during each trial period. Vaginal discharge (2%), vaginal odour (2%), and bacterial vaginitis (2%) were assessed as possibly or probably related to the vaginal ring. Thirty-four percent of participants had sexually transmitted infections (STIs) at screening, compared to 12% of participants who tested positive for STIs at crossover and the final trial visit. Three participants (2%) tested HIV positive during the trial. The silicone elastomer vaginal ring had no safety concerns, demonstrating a profile favorable for further development for topical release of antiretroviral-based microbicides.

Study on the combined influence of battery models and sizing strategy for hybrid and battery-based electric vehicles

DEFF Research Database (Denmark)

Pinto, Cláudio; Barreras, Jorge V.; de Castro, Ricardo

2017-01-01

This paper presents a study of the combined influence of battery models and sizing strategy for hybrid and battery-based electric vehicles. In particular, the aim is to find the number of battery (and supercapacitor) cells to propel a light vehicle to run two different standard driving cycles....... Despite the same tendency, when a hybrid vehicle is taken into account, the influence of the battery models is dependent on the sizing strategy. In this work, two sizing strategies are evaluated: dynamic programming and filter-based. For the latter, the complexity of the battery model has a clear....... Three equivalent circuit models are considered to simulate the battery electrical performance: linear static, non-linear static and non-linear with first-order dynamics. When dimensioning a battery-based vehicle, less complex models may lead to a solution with more battery cells and higher costs...

Power analysis and simulation of a vehicle under combined loads

International Nuclear Information System (INIS)

Khayyam, H.; Kouzani, A.Z.; Khoshmanesh, K.; Hu, E.

2008-01-01

Reducing fuel consumption in vehicles offers many obvious economic benefits, and also helps reduce air pollution emission levels. Mechanical engineers and automotive researches have continuously searched for ways to optimize fuel consumption in vehicles. This paper presented an analytical model of fuel consumption (AMFC) in an effort to coordinate the driving power and manage the overall fuel consumption for an internal combustion engine vehicle. The model calculated the different loads applied on the vehicle, such as road-slope, road-friction, wind-drag, accessories, and mechanical losses. It also solved the combustion equation of the engine under different working conditions including various fuel compositions, excess airs and air inlet temperatures. The model then determined the contribution of each load to signify the energy distribution and power flows of the vehicle. In order to assess the model's sensitivity to different loads, the following four simulations were conducted: flat-windless, flat-windy, sloppy-windless, sloppy-windy. The average fuel consumption for the four simulations was presented. The paper outlined the specification of the vehicle and environment as well as the simulation methodology. The model, algorithm, slope simulation, and drive strategy were presented. It was concluded that the power consumption significantly increased where the slope friction came into play and that the model has the potential to assist in vehicle energy management. 16 refs., 4 tabs., 14 figs

Plasmid-Mediated Resistance to Thrombin-Induced Platelet Microbicidal Protein in Staphylococci: Role of the qacA Locus

OpenAIRE

Kupferwasser, Leon Iri; Skurray, Ronald A.; Brown, Melissa H.; Firth, Neville; Yeaman, Michael R.; Bayer, Arnold S.

1999-01-01

Thrombin-induced platelet microbicidal protein 1 (tPMP-1) is a small, cationic peptide released from rabbit platelets following thrombin stimulation. In vitro resistance to this peptide among strains of Staphylococcus aureus correlates with the survival advantage of such strains at sites of endothelial damage in humans as well as in experimental endovascular infections. The mechanisms involved in the phenotypic resistance of S. aureus to tPMP-1 are not fully delineated. The plasmid-encoded st...

High Concentrations of Sodium Chloride Improve Microbicidal Activity of Ibuprofen against Common Cystic Fibrosis Pathogens

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Adrián J. Muñoz

2018-05-01

Full Text Available Ibuprofen (IBU-H, a widely used anti-inflammatory, also shows a marked antimicrobial effect against several bacterial species, including those involved in cystic fibrosis such as Pseudomona aeruginosa, methicillin resistant Staphylococcus aureus and Burkholderia cepacia complex. Additionally, our results show significant synergy between water soluble Na-ibuprofen (IBU-Na and ionic strength. Salt concentrations above 0.5 M modify the zeta potential promoting the action of Na-IBU; thus, with 1 M sodium chloride, IBU-Na is ten times more efficient than in the absence of ionic strength, and the minimum effective contact time is reduced from hours to minutes. In short time periods, where neither IBU-Na nor controls with 1 M NaCl show activity, the combination of both leads to a reduction in the bacterial load. We also analyzed whether the changes caused by salt on the bacterial membrane also promoted the activity of other microbicide compounds used in cystic fibrosis like gentamicin, tobramycin and phosphomycin. The results show that the presence of ionic strength only enhanced the bactericidal activity of the amphipathic molecule of IBU-Na. In this respect, the effect of saline concentration was also reflected in the surface properties of IBU-Na, where, in addition to the clear differences observed between 145 mM and 1 M, singular behaviors were also found, different in each condition. The combination of anti-inflammatory activity and this improved bactericidal effect of Na-IBU in hypertonic solution provides a new alternative for the treatment of respiratory infections of fibrotic patients based on known and widely used compounds.

The sheep as a model of preclinical safety and pharmacokinetic evaluations of candidate microbicides.

Science.gov (United States)

Holt, Jonathon D S; Cameron, David; Dias, Nicola; Holding, Jeremy; Muntendam, Alex; Oostebring, Freddy; Dreier, Peter; Rohan, Lisa; Nuttall, Jeremy

2015-07-01

When developing novel microbicide products for the prevention of HIV infection, the preclinical safety program must evaluate not only the active pharmaceutical ingredient but also the product itself. To that end, we applied several relatively standard toxicology study methodologies to female sheep, incorporating an assessment of the pharmacokinetics, safety, tolerability, and local toxicity of a dapivirine-containing human vaginal ring formulation (Dapivirine Vaginal Ring-004). We performed a 3-month general toxicology study, a preliminary pharmacokinetic study using drug-loaded vaginal gel, and a detailed assessment of the kinetics of dapivirine delivery to plasma, vaginal, and rectal fluid and rectal, vaginal, and cervical tissue over 28 days of exposure and 3 and 7 days after removal of the ring. The findings of the general toxicology study supported the existing data from both preclinical and clinical studies in that there were no signs of toxicity related to dapivirine. In addition, the presence of the physical dapivirine ring did not alter local or systemic toxicity or the pharmacokinetics of dapivirine. Pharmacokinetic studies indicated that the dapivirine ring produced significant vaginal tissue levels of dapivirine. However, no dapivirine was detected in cervical tissue samples using the methods described here. Plasma and vaginal fluid levels were lower than those in previous clinical studies, while there were detectable dapivirine levels in the rectal tissue and fluid. All tissue and fluid levels tailed off rapidly to undetectable levels following removal of the ring. The sheep represents a very useful model for the assessment of the safety and pharmacokinetics of microbicide drug delivery devices, such as the vaginal ring. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Electric and hybrid vehicles

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1979-01-01

Report characterizes state-of-the-art electric and hybrid (combined electric and heat engine) vehicles. Performance data for representative number of these vehicles were obtained from track and dynamometer tests. User experience information was obtained from fleet operators and individual owners of electric vehicles. Data on performance and physical characteristics of large number of vehicles were obtained from manufacturers and available literature.

Vehicle parts detection based on Faster - RCNN with location constraints of vehicle parts feature point

Science.gov (United States)

Yang, Liqin; Sang, Nong; Gao, Changxin

2018-03-01

Vehicle parts detection plays an important role in public transportation safety and mobility. The detection of vehicle parts is to detect the position of each vehicle part. We propose a new approach by combining Faster RCNN and three level cascaded convolutional neural network (DCNN). The output of Faster RCNN is a series of bounding boxes with coordinate information, from which we can locate vehicle parts. DCNN can precisely predict feature point position, which is the center of vehicle part. We design an output strategy by combining these two results. There are two advantages for this. The quality of the bounding boxes are greatly improved, which means vehicle parts feature point position can be located more precise. Meanwhile we preserve the position relationship between vehicle parts and effectively improve the validity and reliability of the result. By using our algorithm, the performance of the vehicle parts detection improve obviously compared with Faster RCNN.

Gene Expression Profiling of Human Vaginal Cells In Vitro Discriminates Compounds with Pro-Inflammatory and Mucosa-Altering Properties: Novel Biomarkers for Preclinical Testing of HIV Microbicide Candidates.

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Irina A Zalenskaya

Full Text Available Inflammation and immune activation of the cervicovaginal mucosa are considered factors that increase susceptibility to HIV infection. Therefore, it is essential to screen candidate anti-HIV microbicides for potential mucosal immunomodulatory/inflammatory effects prior to further clinical development. The goal of this study was to develop an in vitro method for preclinical evaluation of the inflammatory potential of new candidate microbicides using a microarray gene expression profiling strategy.To this end, we compared transcriptomes of human vaginal cells (Vk2/E6E7 treated with well-characterized pro-inflammatory (PIC and non-inflammatory (NIC compounds. PICs included compounds with different mechanisms of action. Gene expression was analyzed using Affymetrix U133 Plus 2 arrays. Data processing was performed using GeneSpring 11.5 (Agilent Technologies, Santa Clara, CA.Microarraray comparative analysis allowed us to generate a panel of 20 genes that were consistently deregulated by PICs compared to NICs, thus distinguishing between these two groups. Functional analysis mapped 14 of these genes to immune and inflammatory responses. This was confirmed by the fact that PICs induced NFkB pathway activation in Vk2 cells. By testing microbicide candidates previously characterized in clinical trials we demonstrated that the selected PIC-associated genes properly identified compounds with mucosa-altering effects. The discriminatory power of these genes was further demonstrated after culturing vaginal cells with vaginal bacteria. Prevotella bivia, prevalent bacteria in the disturbed microbiota of bacterial vaginosis, induced strong upregulation of seven selected PIC-associated genes, while a commensal Lactobacillus gasseri associated to vaginal health did not cause any changes.In vitro evaluation of the immunoinflammatory potential of microbicides using the PIC-associated genes defined in this study could help in the initial screening of candidates prior

Optimized Benzalkonium Chloride Gel: A Potential Vaginal Microbicides

Institute of Scientific and Technical Information of China (English)

Xun-cheng DING; Wei-hua LI; Jie-fei LI; Qiang-yi WANG

2007-01-01

Objective To develop an optimized BZK gel with good pharmaceutical effect and less toxicity to vaginal mucosa.Methods Four methods as below were used to research the spermicidal activity of BZK gel: 1)in vitro spermicidal test; 2) in vivo spermicidal test in rabbits; 3) anti-fertility test in rabbits; 4)contraceptive test in rabbits. Mucosal irritation test was used in rats to evaluate the safety of optimized BZK gel. Microbiological assessments were used to research anti-STI pathogens (including treponema pallidum, neisseria gonorrhoeae, trichomona vaginalis, candida albicans,ureaplama urealyticum, herpes simplex virus type-2, chlamydiae trachomatis) effect of optimized BZK gel.Results In vitro spermicidal test, EC50 of BZK gel was 0.029 mg/ml, a little higher than that of N-9 (0.019 mg/ml). The MIC of BZK gel was 0.25 mg/ml, similar to that of N-9 (0.20 mg/ml).The vaginal mucosal irritation test in rats showed that 0.429% BZK gel showed only minimal vaginal irritation, and did not damage the vaginal epithelium or cause local inflammation in rats. Microbiological assessments showed that optimized BZK gel could inhibit or inactivate common STI pathogens even after 3-fold or 5-fold dilution.Conclusion Optimized BZK gel was an effective microbicides.

Testing of viscous anti-HIV microbicides using Lactobacillus.

Science.gov (United States)

Moncla, B J; Pryke, K; Rohan, L C; Yang, H

2012-02-01

The development of topical microbicides for intravaginal use to prevent HIV infection requires that the drugs and formulated products be nontoxic to the endogenous vaginal Lactobacillus. In 30min exposure tests we found dapivirine, tenofovir and UC781 (reverse transcriptase inhibitor anti-HIV drugs) as pure drugs or formulated as film or gel products were not deleterious to Lactobacillus species; however, PSC-RANTES (a synthetic CCR5 antagonist) killed 2 strains of Lactobacillus jensenii. To demonstrate the toxicity of formulated products a new assay was developed for use with viscous and non-viscous samples that we have termed the Lactobacillus toxicity test. We found that the vortex mixing of vaginal Lactobacillus species can lead to reductions in bacterial viability. Lactobacillus can survive briefly, about 2s, but viability declines with increased vortex mixing. The addition of heat inactivated serum or bovine serum albumin, but not glycerol, prevented the decrease in bacterial viability. Bacillus atrophaeus spores also demonstrated loss of viability upon extended mixing. We observed that many of the excipients used in film formulation and the films themselves also afford protection from the killing during vortex mixing. This method is of relevance for toxicity for cidal activities of viscous products. Copyright © 2011 Elsevier B.V. All rights reserved.

Acceptability of a novel vaginal microbicide during a safety trial among low-risk women.

Science.gov (United States)

Bentley, M E; Morrow, K M; Fullem, A; Chesney, M A; Horton, S D; Rosenberg, Z; Mayer, K H

2000-01-01

The increasing recognition that women who are unable or unwilling to discuss or use condoms with their sexual partners need female-controlled methods for preventing sexually transmitted diseases (STDs), including HIV, has led to considerable focus on the development of vaginal microbicides. While many such products are being tested for safety and effectiveness, clinical trials generally overlook another key factor in a product's impact on infection rates-its acceptability to users. A Phase I clinical trial of a microbicidal gel included an assessment of the product's acceptability among 27 low-risk participants. Information on acceptability was gathered from structured interviews, participants' daily diaries and unstructured exit interviews. Participants reported only minor side effects of product use, such as itching, burning and difficulty urinating; two women developed candida infections while participating in the study. None of the side effects could be conclusively linked to use of the gel. Some women noted product discharge and messiness as drawbacks of the method, but this experience varied according to how often the women applied the gel. For example, one-third of those who used it once daily said that at least some of the time, it was too "wet or drippy," compared with two-thirds of women who inserted the gel twice a day. However, participants considered these "nuisance factors" that could be outweighed by the potential protective characteristics of the product. The majority reported that they would use the product if it were available and proven efficacious, and if they perceived that they were at risk of STD infection. Additional testing of this product is urgently needed. Furthermore, as other products approach Phase I testing, acceptability assessments should be a key component of clinical trials.

Precise engineering of dapivirine-loaded nanoparticles for the development of anti-HIV vaginal microbicides.

Science.gov (United States)

das Neves, José; Sarmento, Bruno

2015-05-01

Polymeric nanoparticles (NPs) have the potential to provide effective and safe delivery of antiretroviral drugs in the context of prophylactic anti-HIV vaginal microbicides. Dapivirine-loaded poly(d,l-lactic-co-glycolic acid) (PLGA) NPs were produced by an emulsion-solvent evaporation method, optimized for colloidal properties using a 3-factor, 3-level Box-Behnken experimental design, and characterized for drug loading, production yield, morphology, thermal behavior, drug release, in vitro cellular uptake, cytotoxicity and pro-inflammatory potential. Also, drug permeability/membrane retention in well-established HEC-1-A and CaSki cell monolayer models as mediated by NPs was assessed in the absence or presence of mucin. Box-Behnken design allowed optimizing monodisperse 170nm drug-loaded NPs. Drug release experiments showed an initial burst effect up to 4h, followed by sustained 24h release at pH 4.2 and 7.4. NPs were readily taken up by different genital and macrophage cell lines as assessed by fluorescence microscopy. Drug-loaded NPs presented lower or at least similar cytotoxicity as compared to the free drug, with up to around one-log increase in half-maximal cytotoxic concentration values. In all cases, no relevant changes in cell pro-inflammatory cytokine/chemokine production were observed. Dapivirine transport across cell monolayers was significantly decreased when mucin was present at the donor side with either NPs or the free drug, thus evidencing the influence of this natural glycoprotein in membrane permeability. Moreover, drug retention in cell monolayers was significantly higher for NPs in comparison with the free drug. Overall, obtained dapivirine-loaded PLGA NPs possess interesting technological and biological features that may contribute to their use as novel safe and effective vaginal microbicides. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Safety, Acceptability and Adherence of Dapivirine Vaginal Ring in a Microbicide Clinical Trial Conducted in Multiple Countries in Sub-Saharan Africa.

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Annalene Nel

Full Text Available This was the first microbicide trial conducted in Africa to evaluate an antiretroviral-containing vaginal ring as an HIV prevention technology for women.The trial assessed and compared the safety, acceptability and adherence to product use of a 4-weekly administered vaginal ring containing the antiretroviral microbicide, dapivirine, with a matching placebo ring among women from four countries in sub-Saharan Africa.280 Healthy, sexually active, HIV-negative women, aged 18 to 40 years were enrolled with 140 women randomised to a dapivirine vaginal ring (25 mg and 140 women to a matching placebo ring, inserted 4-weekly and used over a 12-week period. Safety was evaluated by pelvic examination, colposcopy, clinical laboratory assessments, and adverse events. Blood samples for determination of plasma concentrations of dapivirine were collected at Weeks 0, 4 and 12. Residual dapivirine levels in returned rings from dapivirine ring users were determined post-trial. Participant acceptability and adherence to ring use were assessed by self-reports.No safety concerns or clinically relevant differences were observed between the dapivirine and placebo ring groups. Plasma dapivirine concentrations immediately prior to ring removal were similar after removal of the first and third ring, suggesting consistent ring use over the 12-week period. No clear relationship was observed between the residual amount of dapivirine in used rings and corresponding plasma concentrations. Self-reported adherence to daily use of the vaginal rings over the 12-week trial period was very high. At the end of the trial, 96% of participants reported that the ring was usually comfortable to wear, and 97% reported that they would be willing to use it in the future if proven effective.The dapivirine vaginal ring has a favourable safety and acceptability profile. If proven safe and effective in large-scale trials, it will be an important component of combination HIV prevention approaches

Safety, Acceptability and Adherence of Dapivirine Vaginal Ring in a Microbicide Clinical Trial Conducted in Multiple Countries in Sub-Saharan Africa.

Science.gov (United States)

Nel, Annalene; Bekker, Linda-Gail; Bukusi, Elizabeth; Hellstrӧm, Elizabeth; Kotze, Philip; Louw, Cheryl; Martinson, Francis; Masenga, Gileard; Montgomery, Elizabeth; Ndaba, Nelisiwe; van der Straten, Ariane; van Niekerk, Neliëtte; Woodsong, Cynthia

2016-01-01

This was the first microbicide trial conducted in Africa to evaluate an antiretroviral-containing vaginal ring as an HIV prevention technology for women. The trial assessed and compared the safety, acceptability and adherence to product use of a 4-weekly administered vaginal ring containing the antiretroviral microbicide, dapivirine, with a matching placebo ring among women from four countries in sub-Saharan Africa. 280 Healthy, sexually active, HIV-negative women, aged 18 to 40 years were enrolled with 140 women randomised to a dapivirine vaginal ring (25 mg) and 140 women to a matching placebo ring, inserted 4-weekly and used over a 12-week period. Safety was evaluated by pelvic examination, colposcopy, clinical laboratory assessments, and adverse events. Blood samples for determination of plasma concentrations of dapivirine were collected at Weeks 0, 4 and 12. Residual dapivirine levels in returned rings from dapivirine ring users were determined post-trial. Participant acceptability and adherence to ring use were assessed by self-reports. No safety concerns or clinically relevant differences were observed between the dapivirine and placebo ring groups. Plasma dapivirine concentrations immediately prior to ring removal were similar after removal of the first and third ring, suggesting consistent ring use over the 12-week period. No clear relationship was observed between the residual amount of dapivirine in used rings and corresponding plasma concentrations. Self-reported adherence to daily use of the vaginal rings over the 12-week trial period was very high. At the end of the trial, 96% of participants reported that the ring was usually comfortable to wear, and 97% reported that they would be willing to use it in the future if proven effective. The dapivirine vaginal ring has a favourable safety and acceptability profile. If proven safe and effective in large-scale trials, it will be an important component of combination HIV prevention approaches for women

Safety, Acceptability and Adherence of Dapivirine Vaginal Ring in a Microbicide Clinical Trial Conducted in Multiple Countries in Sub-Saharan Africa

Science.gov (United States)

Nel, Annalene; Bekker, Linda-Gail; Bukusi, Elizabeth; Hellstrӧm, Elizabeth; Kotze, Philip; Louw, Cheryl; Martinson, Francis; Masenga, Gileard; Montgomery, Elizabeth; Ndaba, Nelisiwe; van der Straten, Ariane; van Niekerk, Neliëtte; Woodsong, Cynthia

2016-01-01

Background This was the first microbicide trial conducted in Africa to evaluate an antiretroviral-containing vaginal ring as an HIV prevention technology for women. Objectives The trial assessed and compared the safety, acceptability and adherence to product use of a 4-weekly administered vaginal ring containing the antiretroviral microbicide, dapivirine, with a matching placebo ring among women from four countries in sub-Saharan Africa. Methods 280 Healthy, sexually active, HIV-negative women, aged 18 to 40 years were enrolled with 140 women randomised to a dapivirine vaginal ring (25 mg) and 140 women to a matching placebo ring, inserted 4-weekly and used over a 12-week period. Safety was evaluated by pelvic examination, colposcopy, clinical laboratory assessments, and adverse events. Blood samples for determination of plasma concentrations of dapivirine were collected at Weeks 0, 4 and 12. Residual dapivirine levels in returned rings from dapivirine ring users were determined post-trial. Participant acceptability and adherence to ring use were assessed by self-reports. Results No safety concerns or clinically relevant differences were observed between the dapivirine and placebo ring groups. Plasma dapivirine concentrations immediately prior to ring removal were similar after removal of the first and third ring, suggesting consistent ring use over the 12-week period. No clear relationship was observed between the residual amount of dapivirine in used rings and corresponding plasma concentrations. Self-reported adherence to daily use of the vaginal rings over the 12-week trial period was very high. At the end of the trial, 96% of participants reported that the ring was usually comfortable to wear, and 97% reported that they would be willing to use it in the future if proven effective. Conclusions The dapivirine vaginal ring has a favourable safety and acceptability profile. If proven safe and effective in large-scale trials, it will be an important component of

State-of-the-art assessment of electric vehicles and hybrid vehicles

Science.gov (United States)

1977-01-01

The Electric and Hybrid Vehicle Research, Development, and Demonstration Act of 1976 (PL 94-413) requires that data be developed to characterize the state of the art of vehicles powered by an electric motor and those propelled by a combination of an electric motor and an internal combustion engine or other power sources. Data obtained from controlled tests of a representative number of sample vehicles, from information supplied by manufacturers or contained in the literature, and from surveys of fleet operators of individual owners of electric vehicles is discussed. The results of track and dynamometer tests conducted by NASA on 22 electric, 2 hybrid, and 5 conventional vehicles, as well as on 5 spark-ignition-engine-powered vehicles, the conventional counterparts of 5 of the vehicles, are presented.

Optimization of the rocket mode trajectory in a rocket based combined cycle (RBCC) engine powered SSTO vehicle

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Foster, Richard W.

1989-07-01

The application of rocket-based combined cycle (RBCC) engines to booster-stage propulsion, in combination with all-rocket second stages in orbital-ascent missions, has been studied since the mid-1960s; attention is presently given to the case of the 'ejector scramjet' RBCC configuration's application to SSTO vehicles. While total mass delivered to initial orbit is optimized at Mach 20, payload delivery capability to initial orbit optimizes at Mach 17, primarily due to the reduction of hydrogen fuel tankage structure, insulation, and thermal protection system weights.

Using the Theory of Combined Friction when Making Mathematical Models of Curvilinear Motion of Tracked Vehicles

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M. V. Vyaznikov

2014-01-01

Full Text Available The paper presents study results of the nonlinear interaction processes between the supporting surface of the track Assembly and the ground in the contact patch, using the mathematical models of friction. For the case blaskapelle motion of a caterpillar, when the resultant of the elementary friction forces is limited by the coupling due to the sliding tracks on the ground, it appears that the increase of the lateral component leads to a decrease of the longitudinal component and the change of direction of the resulting force. As a result, with increasing angular velocity of the tracked vehicle a longitudinal component of the friction force decreases, which is the geometric factor and is defined by the locus of friction for a given type of soil. In the development of this well-known model is considered the general case of friction, which describes the effect of reducing the coefficient of friction in the contact patch at increasing the angular velocity of rotation. To describe this process is used the model of the combined friction which occurs when the surface of the body is doing at the same time the rotational and translational motion. The resulting expression for the resultant of forces of friction and the moment of resistance to rotation based on the decomposition of the first order Pade for a flat spot track Assembly with ground of rectangular shape. With combined friction any arbitrarily small perturbation force acting parallel to the surface of the contact spot, leads to slip. The paper considers the possibility of using the model of the combined friction to research a sustainability curvilinear motion of tracked vehicles. The proposed motion of the machine in the mode of skidding on the basis of the frictionslip. The interpretation of the physical processes occurring in the contact area, on the basis of the theory of the combined friction would allow using this mathematical model in the algorithm structure of automatic traffic control

A Combined Cooperative Braking Model with a Predictive Control Strategy in an Electric Vehicle

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Hongqiang Guo

2013-12-01

Full Text Available Cooperative braking with regenerative braking and mechanical braking plays an important role in electric vehicles for energy-saving control. Based on the parallel and the series cooperative braking models, a combined model with a predictive control strategy to get a better cooperative braking performance is presented. The balance problem between the maximum regenerative energy recovery efficiency and the optimum braking stability is solved through an off-line process optimization stream with the collaborative optimization algorithm (CO. To carry out the process optimization stream, the optimal Latin hypercube design (Opt LHD is presented to discrete the continuous design space. To solve the poor real-time problem of the optimization, a high-precision predictive model based on the off-line optimization data of the combined model is built, and a predictive control strategy is proposed and verified through simulation. The simulation results demonstrate that the predictive control strategy and the combined model are reasonable and effective.

Hybrid Electric Vehicle Testing | Transportation Research | NREL

Science.gov (United States)

Hybrid Electric Vehicle Evaluations Hybrid Electric Vehicle Evaluations How Hybrid Electric Vehicles Work Hybrid electric vehicles combine a primary power source, an energy storage system, and an is used to propel the vehicle during normal drive cycles. The batteries supply additional power for

Combining Market-Based Control with Distribution Grid Constraints when Coordinating Electric Vehicle Charging

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Geert Deconinck

2015-12-01

Full Text Available The charging of electric vehicles (EVs impacts the distribution grid, and its cost depends on the price of electricity when charging. An aggregator that is responsible for a large fleet of EVs can use a market-based control algorithm to coordinate the charging of these vehicles, in order to minimize the costs. In such an optimization, the operational parameters of the distribution grid, to which the EVs are connected, are not considered. This can lead to violations of the technical constraints of the grid (e.g., under-voltage, phase unbalances; for example, because many vehicles start charging simultaneously when the price is low. An optimization that simultaneously takes the economic and technical aspects into account is complex, because it has to combine time-driven control at the market level with event-driven control at the operational level. Different case studies investigate under which circumstances the market-based control, which coordinates EV charging, conflicts with the operational constraints of the distribution grid. Especially in weak grids, phase unbalance and voltage issues arise with a high share of EVs. A low-level voltage droop controller at the charging point of the EV can be used to avoid many grid constraint violations, by reducing the charge power if the local voltage is too low. While this action implies a deviation from the cost-optimal operating point, it is shown that this has a very limited impact on the business case of an aggregator, and is able to comply with the technical distribution grid constraints, even in weak distribution grids with many EVs.

A robust observer based on H∞ filtering with parameter uncertainties combined with Neural Networks for estimation of vehicle roll angle

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Boada, Beatriz L.; Boada, Maria Jesus L.; Vargas-Melendez, Leandro; Diaz, Vicente

2018-01-01

Nowadays, one of the main objectives in road transport is to decrease the number of accident victims. Rollover accidents caused nearly 33% of all deaths from passenger vehicle crashes. Roll Stability Control (RSC) systems prevent vehicles from untripped rollover accidents. The lateral load transfer is the main parameter which is taken into account in the RSC systems. This parameter is related to the roll angle, which can be directly measured from a dual-antenna GPS. Nevertheless, this is a costly technique. For this reason, roll angle has to be estimated. In this paper, a novel observer based on H∞ filtering in combination with a neural network (NN) for the vehicle roll angle estimation is proposed. The design of this observer is based on four main criteria: to use a simplified vehicle model, to use signals of sensors which are installed onboard in current vehicles, to consider the inaccuracy in the system model and to attenuate the effect of the external disturbances. Experimental results show the effectiveness of the proposed observer.

Evaluating the accuracy of vehicle tracking data obtained from Unmanned Aerial Vehicles

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Giuseppe Guido

2016-10-01

Full Text Available This paper presents a methodology for tracking moving vehicles that integrates Unmanned Aerial Vehicles with video processing techniques. The authors investigated the usefulness of Unmanned Aerial Vehicles to capture reliable individual vehicle data by using GPS technology as a benchmark. A video processing algorithm for vehicles trajectory acquisition is introduced. The algorithm is based on OpenCV libraries. In order to assess the accuracy of the proposed video processing algorithm an instrumented vehicle was equipped with a high precision GPS. The video capture experiments were performed in two case studies. From the field, about 24,000 positioning data were acquired for the analysis. The results of these experiments highlight the versatility of the Unmanned Aerial Vehicles technology combined with video processing technique in monitoring real traffic data.

Combined braking system for hybrid vehicle

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Kulekina, A. V.; Bakholdin, P. A.; Shchurov, N. I.

2017-10-01

The paper presents an analysis of surface vehicle’s existing braking systems. The technical solution and brake-system design were developed for use of regenerative braking energy. A technical parameters comparison of energy storage devices of various types was made. Based on the comparative analysis, it was decided to use supercapacitor because of its applicability for an electric drive intermittent operation. The calculation methods of retarder key components were proposed. Therefrom, it was made a conclusion that rebuild gasoline-electric vehicles are more efficient than gasoline ones.

Thermoreversible Gel Formulations Containing Sodium Lauryl Sulfate or n-Lauroylsarcosine as Potential Topical Microbicides against Sexually Transmitted Diseases

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Roy, Sylvie; Gourde, Pierrette; Piret, Jocelyne; Désormeaux, André; Lamontagne, Julie; Haineault, Caroline; Omar, Rabeea F.; Bergeron, Michel G.

2001-01-01

The microbicidal efficacies of two anionic surfactants, sodium lauryl sulfate (SLS) and n-lauroylsarcosine (LS), were evaluated in cultured cells and in a murine model of herpes simplex type 2 (HSV-2) intravaginal infection. In vitro studies showed that SLS and LS were potent inhibitors of the infectivity of HSV-2 strain 333. The concentrations of SLS which inhibit viral infectivity by 50% (50% inhibitory dose) and 90% (90% inhibitory dose) were 32.67 and 46.53 μM, respectively, whereas the corresponding values for LS were 141.76 and 225.30 μM. In addition, intravaginal pretreatment of mice with thermoreversible gel formulations containing 2.5% SLS or 2.5% LS prior to the inoculation of HSV-2 strain 333 completely prevented the development of genital herpetic lesions and the lethality associated with infection. Of prime interest, no infectious virus could be detected in mouse vaginal mucosa. Both formulations still provided significant protection when viral challenge was delayed until 1 h after pretreatment. Finally, intravaginal application of gel formulations containing 2.5% SLS or 2.5% LS once daily for 14 days to rabbits did not induce significant irritations to the genital mucosa, as demonstrated from macroscopic and histopathologic examinations. These results suggest that thermoreversible gel formulations containing SLS or LS could represent potent and safe topical microbicides for the prevention of HSV-2 and possibly other sexually transmitted pathogens, including human immunodeficiency virus. PMID:11353610

Hybrid vehicle powertrain system with power take-off driven vehicle accessory

Science.gov (United States)

Beaty, Kevin D.; Bockelmann, Thomas R.; Zou, Zhanijang; Hope, Mark E.; Kang, Xiaosong; Carpenter, Jeffrey L.

2006-09-12

A hybrid vehicle powertrain system includes a first prime mover, a first prime mover driven power transmission mechanism having a power take-off adapted to drive a vehicle accessory, and a second prime mover. The second prime mover is operable to drive the power transmission mechanism alone or in combination with the first prime mover to provide power to the power take-off through the power transmission mechanism. The invention further includes methods for operating a hybrid vehicle powertrain system.

Air-Conditioning for Electric Vehicles

Science.gov (United States)

Popinski, Z.

1984-01-01

Combination of ammonia-absorption refrigerator, roof-mounted solar collectors, and 200 degrees C service electric-vehicle motor provides evaporative space-heating/space cooling system for electric-powered and hybrid fuel/electric vehicles.

Combination of Markov chain and optimal control solved by Pontryagin’s Minimum Principle for a fuel cell/supercapacitor vehicle

International Nuclear Information System (INIS)

Hemi, Hanane; Ghouili, Jamel; Cheriti, Ahmed

2015-01-01

Highlights: • A combination of Markov chain and an optimal control solved by Pontryagin’s Minimum Principle is presented. • This strategy is applied to hybrid electric vehicle dynamic model. • The hydrogen consumption is analyzed for two different vehicle mass and drive cycle. • The supercapacitor and fuel cell behavior is analyzed at high or sudden required power. - Abstract: In this article, a real time optimal control strategy based on Pontryagin’s Minimum Principle (PMP) combined with the Markov chain approach is used for a fuel cell/supercapacitor electrical vehicle. In real time, at high power and at high speed, two phenomena are observed. The first is obtained at higher required power, and the second is observed at sudden power demand. To avoid these situations, the Markov chain model is proposed to predict the future power demand during a driving cycle. The optimal control problem is formulated as an equivalent consumption minimization strategy (ECMS), that has to be solved by using the Pontryagin’s Minimum Principle. A Markov chain model is added as a separate block for a prediction of required power. This approach and the whole system are modeled and implemented using the MATLAB/Simulink. The model without Markov chain block and the model is with it are compared. The results presented demonstrate the importance of a Markov chain block added to a model

Safety and anti-HIV assessments of natural vaginal cleansing products in an established topical microbicides in vitro testing algorithm

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Jones Maureen

2010-07-01

Full Text Available Abstract Background At present, there is no effective vaccine or other approved product for the prevention of sexually transmitted human immunodeficiency virus type 1 (HIV-1 infection. It has been reported that women in resource-poor communities use vaginally applied citrus juices as topical microbicides. These easily accessible food products have historically been applied to prevent pregnancy and sexually transmitted diseases. The aim of this study was to evaluate the efficacy and cytotoxicity of these substances using an established topical microbicide testing algorithm. Freshly squeezed lemon and lime juice and household vinegar were tested in their original state or in pH neutralized form for efficacy and cytotoxicity in the CCR5-tropic cell-free entry and cell-associated transmission assays, CXCR4-tropic entry and fusion assays, and in a human PBMC-based anti-HIV-1 assay. These products were also tested for their effect on viability of cervico-vaginal cell lines, human cervical explant tissues, and beneficial Lactobacillus species. Results Natural lime and lemon juice and household vinegar demonstrated anti-HIV-1 activity and cytotoxicity in transformed cell lines. Neutralization of the products reduced both anti-HIV-1 activity and cytotoxicity, resulting in a low therapeutic window for both acidic and neutralized formulations. For the natural juices and vinegar, the IC50 was ≤ 3.5 (0.8-3.5% and the TC50 ≤ 6.3 (1.0-6.3%. All three liquid products inhibited viability of beneficial Lactobacillus species associated with vaginal health. Comparison of three different toxicity endpoints in the cervical HeLa cell line revealed that all three products affected membrane integrity, cytosolic enzyme release, and dehydrogenase enzyme activity in living cells. The juices and vinegar also exerted strong cytotoxicity in cervico-vaginal cell lines, mainly due to their acidic pH. In human cervical explant tissues, treatment with 5% lemon or lime juice

Assessment of topical microbicides to prevent HIV-1 transmission: concepts, testing, lessons learned.

Science.gov (United States)

Friend, David R; Kiser, Patrick F

2013-09-01

The development of topically applied products capable of preventing vaginal and rectal transmission of HIV-1 has been on-going for nearly 20 years. Despite this, only one clinical trial has demonstrated protection against sexual transmission of HIV-1 in women. This review covers the development of microbicides, also referred to as topical pre-exposure prophylaxis (PrEP), through three stages. The first stage focused on nonspecific agents, including surfactants such as nonoxynol-9 (N-9), to prevent HIV-1 transmission. Unfortunately, N-9 enhanced susceptibility to sexual transmission of HIV-1 when evaluated for efficacy. Soon thereafter, other nonspecific agents (polyanions) were quickly moved into large efficacy trials. Due to a lack of coordination among investigators and funders, a large investment was made in a class of compounds shown ultimately to be ineffective, although poor adherence may have contributed to these findings. The second stage involved the assessment of the antiretroviral drug tenofovir, formulated as a vaginal gel, which was found to be modestly effective in a Phase IIb trial (CAPRISA-004) when dosed in a coitally-dependent manner. In another Phase IIb trial, VOICE (MTN-003), tenofovir gel was found to be ineffective when dosed once-daily in a coitally-independent manner. Based on pharmacokinetic data, it was concluded the participants were poorly adherent to this dosing regimen, leading to a lack of efficacy. Tenofovir gel is currently in a Phase III safety and efficacy trial in South Africa (FACTS-001), using the coitally-dependent dosing regimen employed in CAPRISA-004. We are now in the third stage of microbicide research. The antiretroviral drug dapivirine is currently in two Phase III safety and efficacy studies formulated as a vaginal ring. It is hoped that the once-monthly dosing regimen will lead to higher adherence than found in the VOICE study. It is now clear that product adherence could be the greatest challenge to demonstrating

Inhibition of HIV-1 infection in ex vivo cervical tissue model of human vagina by palmitic acid; implications for a microbicide development.

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Xudong Lin

Full Text Available BACKGROUND: Approximately 80% of all new HIV-1 infections are acquired through sexual contact. Currently, there is no clinically approved microbicide, indicating a clear and urgent therapeutic need. We recently reported that palmitic acid (PA is a novel and specific inhibitor of HIV-1 fusion and entry. Mechanistically, PA inhibits HIV-1 infection by binding to a novel pocket on the CD4 receptor and blocks efficient gp120-to-CD4 attachment. Here, we wanted to assess the ability of PA to inhibit HIV-1 infection in cervical tissue ex vivo model of human vagina, and determine its effect on Lactobacillus (L species of probiotic vaginal flora. PRINCIPAL FINDINGS: Our results show that treatment with 100-200 µM PA inhibited HIV-1 infection in cervical tissue by up to 50%, and this treatment was not toxic to the tissue or to L. crispatus and jensenii species of vaginal flora. In vitro, in a cell free system that is independent of in vivo cell associated CD4 receptor; we determined inhibition constant (Ki to be ∼2.53 µM. SIGNIFICANCE: These results demonstrate utility of PA as a model molecule for further preclinical development of a safe and potent HIV-1 entry microbicide inhibitor.

Assessing the stationary energy storage equivalency of vehicle-to-grid charging battery electric vehicles

International Nuclear Information System (INIS)

Tarroja, Brian; Zhang, Li; Wifvat, Van; Shaffer, Brendan; Samuelsen, Scott

2016-01-01

A study has been performed to understand the quantitative impact of key differences between vehicle-to-grid and stationary energy storage systems on renewable utilization, greenhouse gas emissions, and balancing fleet operation, using California as the example. To simulate the combined electricity and light-duty transportation system, a detailed electric grid dispatch model (including stationary energy storage systems) was combined with an electric vehicle charging dispatch model that incorporates conventional smart and vehicle-to-grid capabilities. By subjecting smaller amounts of renewable energy to round-trip efficiency losses and thereby increasing the efficiency of renewable utilization, it was found that vehicle-to-grid energy storage can achieve higher renewable utilization levels and reduced greenhouse gas emissions compared to stationary energy storage systems. Vehicle-to-grid energy storage, however, is not as capable of balancing the power plant fleet compared to stationary energy storage systems due to the constraints of consumer travel patterns. The potential benefits of vehicle-to-grid are strongly dependent on the availability of charging infrastructure at both home and workplaces, with potential benefits being compromised with residential charging availability only. Overall, vehicle-to-grid energy storage can provide benefits over stationary energy storage depending on the system attribute selected for improvement, a finding amenable to managing through policy. - Highlights: • Using vehicle-to-grid-based storage increases the efficiency of renewable energy utilization. • Vehicle-to-grid-based energy storage has less overall flexibility compared to stationary energy storage. • The discharge ability of vehicle-to-grid-based provides a significant benefit over one-way smart charging. • Both workplace and home charging are critical for providing vehicle-to-grid-related benefits. • Increasing charging intelligence reduces stationary energy

Research overview : design specifications for hybrid vehicles

NARCIS (Netherlands)

Hofman, T.; Druten, van R.M.

2004-01-01

In this paper a method is proposed for determination of the design specifications regarding the energy exchange systems for different chargesustaining hybrid vehicles of different vehicle classes. Hybrid drivetrains for vehicles combine multiple power sources in order to increase the driving

Combining Front Vehicle Detection with 3D Pose Estimation for a Better Driver Assistance

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Yu Peng

2012-09-01

Full Text Available Driver assistant systems enhance traffic safety and efficiency. The accurate 3D pose of a front vehicle can help a driver to make the right decision on the road. We propose a novel real-time system to estimate the 3D pose of the front vehicle. This system consists of two parallel threads: vehicle rear tracking and mapping. The vehicle rear is first identified in the video captured by an onboard camera, after license plate localization and foreground extraction. The 3D pose estimation technique is then employed with respect to the extracted vehicle rear. Most current 3D pose estimation techniques need prior models or a stereo initialization with user cooperation. It is extremely difficult to obtain prior models due to the varying appearance of vehicles' rears. Moreover, it is unsafe to ask for drivers' cooperation when a vehicle is running. In our system, two initial keyframes for stereo algorithms are automatically extracted by vehicle rear detection and tracking. Map points are defined as a collection of point features extracted from the vehicle's rear with their 3D information. These map points are inferences that relate the 2D features detected in following vehicles' rears with the 3D world. The relative 3D pose of the onboard camera to the front vehicle rear is then estimated through matching the map points with point features detected on the front vehicle rear. We demonstrate the capabilities of our system by testing on real-time and synthesized videos. In order to make the experimental analysis visible, we demonstrated an estimated 3D pose through augmented reality, which needs accurate and real-time 3D pose estimation.

Vision-Based Leader Vehicle Trajectory Tracking for Multiple Agricultural Vehicles.

Science.gov (United States)

Zhang, Linhuan; Ahamed, Tofael; Zhang, Yan; Gao, Pengbo; Takigawa, Tomohiro

2016-04-22

The aim of this study was to design a navigation system composed of a human-controlled leader vehicle and a follower vehicle. The follower vehicle automatically tracks the leader vehicle. With such a system, a human driver can control two vehicles efficiently in agricultural operations. The tracking system was developed for the leader and the follower vehicle, and control of the follower was performed using a camera vision system. A stable and accurate monocular vision-based sensing system was designed, consisting of a camera and rectangular markers. Noise in the data acquisition was reduced by using the least-squares method. A feedback control algorithm was used to allow the follower vehicle to track the trajectory of the leader vehicle. A proportional-integral-derivative (PID) controller was introduced to maintain the required distance between the leader and the follower vehicle. Field experiments were conducted to evaluate the sensing and tracking performances of the leader-follower system while the leader vehicle was driven at an average speed of 0.3 m/s. In the case of linear trajectory tracking, the RMS errors were 6.5 cm, 8.9 cm and 16.4 cm for straight, turning and zigzag paths, respectively. Again, for parallel trajectory tracking, the root mean square (RMS) errors were found to be 7.1 cm, 14.6 cm and 14.0 cm for straight, turning and zigzag paths, respectively. The navigation performances indicated that the autonomous follower vehicle was able to follow the leader vehicle, and the tracking accuracy was found to be satisfactory. Therefore, the developed leader-follower system can be implemented for the harvesting of grains, using a combine as the leader and an unloader as the autonomous follower vehicle.

State estimation for integrated vehicle dynamics control

NARCIS (Netherlands)

Zuurbier, J.; Bremmer, P.

2002-01-01

This paper discusses a vehicle controller and a state estimator that was implemented and tested in a vehicle equipped with a combined braking and chassis control system to improve handling. The vehicle dynamics controller consists of a feed forward body roll compensation and a feedback stability

Resistance to and killing by the sporicidal microbicide peracetic acid.

Science.gov (United States)

Leggett, Mark J; Schwarz, J Spencer; Burke, Peter A; Mcdonnell, Gerald; Denyer, Stephen P; Maillard, Jean-Yves

2015-03-01

To elucidate the mechanisms of spore resistance to and killing by the oxidizing microbicide peracetic acid (PAA). Mutants of Bacillus subtilis lacking specific spore structures were used to identify resistance properties in spores and to understand the mechanism of action of PAA. We also assessed the effect of PAA treatment on a number of spore properties including heat tolerance, membrane integrity and germination. The spore coat is essential for spore PAA resistance as spores with defective coats were greatly sensitized to PAA treatment. Small acid-soluble spore proteins apparently provide no protection against PAA. Defects in spore germination, specifically in germination via the GerB and GerK but not the GerA germination receptors, as well as leakage of internal components suggest that PAA is active at the spore inner membrane. It is therefore likely that the inner membrane is the major site of PAA's sporicidal activity. PAA treatment targets the spore membrane, with some of its activity directed specifically against the GerB and GerK germination receptors. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Perceptions among Dutch men who have sex with men and their willingness to use rectal microbicides and oral pre-exposure prophylaxis to reduce HIV risk--a preliminary study

NARCIS (Netherlands)

Marra, Elske; Hankins, Catherine A.

2015-01-01

Oral pre-exposure prophylaxis (PrEP) with antiretroviral (ARV) tablets and topical PrEP or microbicides containing ARV drugs could help to reduce HIV incidence. These methods hold promise for men who have sex with men (MSM) who are at higher risk of acquiring HIV. This mixed-methods study in the

32 CFR 935.51 - Motor vehicle violations.

Science.gov (United States)

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Motor vehicle violations. 935.51 Section 935.51... REGULATIONS WAKE ISLAND CODE Penalties § 935.51 Motor vehicle violations. Whoever is found guilty of a... than 30 days, or suspension or revocation of his motor vehicle operator's permit, or any combination or...

Transporters for Antiretroviral Drugs in Colorectal CD4+ T Cells and Circulating α4β7 Integrin CD4+ T Cells: Implications for HIV Microbicides.

Science.gov (United States)

Mukhopadhya, Indrani; Murray, Graeme I; Duncan, Linda; Yuecel, Raif; Shattock, Robin; Kelly, Charles; Iannelli, Francesco; Pozzi, Gianni; El-Omar, Emad M; Hold, Georgina L; Hijazi, Karolin

2016-09-06

CD4+ T lymphocytes in the colorectal mucosa are key in HIV-1 transmission and dissemination. As such they are also the primary target for antiretroviral (ARV)-based rectal microbicides for pre-exposure prophylaxis. Drug transporters expressed in mucosal CD4+ T cells determine ARV distribution across the cell membrane and, most likely, efficacy of microbicides. We describe transporters for antiretroviral drugs in colorectal mucosal CD4+ T lymphocytes and compare gene expression with circulating α4β7+CD4+ T cells, which traffic to the intestine and have been shown to be preferentially infected by HIV-1. Purified total CD4+ T cells were obtained from colorectal tissue and blood samples by magnetic separation. CD4+ T cells expressing α4β7 integrin were isolated by fluorescence-activated cell sorting from peripheral blood mononuclear cells of healthy volunteers. Expressions of 15 efflux and uptake drug transporter genes were quantified using Taqman qPCR assays. Expression of efflux transporters MRP3, MRP5, and BCRP and uptake transporter CNT2 were significantly higher in colorectal CD4+ T cells compared to circulating CD4+ T cells (p = 0.01-0.03). Conversely, circulating α4β7+CD4+ T cells demonstrated significantly higher expression of OATPD compared to colorectal CD4+ T cells (p = 0.001). To the best of our knowledge this is the first report of drug transporter gene expression in colorectal CD4+ and peripheral α4β7+CD4+ T cells. The qualitative and quantitative differences in drug transporter gene expression profiles between α4β7+CD4+ T cells and total mucosal CD4+ T cells may have significant implications for the efficacy of rectally delivered ARV-microbicides. Most notably, we have identified efflux drug transporters that could be targeted by selective inhibitors or beneficial drug-drug interactions to enhance intracellular accumulation of antiretroviral drugs.

Project Gel a Randomized Rectal Microbicide Safety and Acceptability Study in Young Men and Transgender Women.

Directory of Open Access Journals (Sweden)

Ian McGowan

Full Text Available The purpose of Project Gel was to determine the safety and acceptability of rectal microbicides in young men who have sex with men (MSM and transgender women (TGW at risk of HIV infection.MSM and TGW aged 18-30 years were enrolled at three sites; Pittsburgh, PA; Boston, MA; and San Juan, PR. Stage 1A was a cross-sectional assessment of sexual health and behavior in MSM and TGW. A subset of participants from Stage 1A were then enrolled in Stage 1B, a 12-week evaluation of the safety and acceptability of a placebo rectal gel. This was followed by the final phase of the study (Stage 2 in which a subset of participants from Stage 1B were enrolled into a Phase 1 rectal safety and acceptability evaluation of tenofovir (TFV 1% gel.248 participants were enrolled into Stage 1A. Participants' average age was 23.3 years. The most common sexually transmitted infection (STIs at baseline were Herpes simplex (HSV-2 (16.1% by serology and rectal Chlamydia trachomatis (CT (10.1% by NAAT. 134 participants were enrolled into Stage 1B. During the 12 week period of follow-up 2 HIV, 5 rectal CT, and 5 rectal Neisseria gonorrhea infections were detected. The majority of adverse events (AEs were infections (N = 56 or gastrointestinal (N = 46 and were mild (69.6% or moderate (28.0%. Of the participants who completed Stage 1B, 24 were enrolled into Stage 2 and randomized (1:1 to receive TFV or placebo gel. All participants completed Stage 2. The majority of AEs were gastrointestinal (N = 10 and of mild (87.2% or moderate (10.3% severity.In this study we were able to enroll a sexually active population of young MSM and TGW who were willing to use rectal microbicides. TFV gel was safe and acceptable and should be further developed as an alternative HIV prevention intervention for this population.ClinicalTrials.gov NCT01283360.

Quantitation of microbicidal activity of mononuclear phagocytes: an in vitro technique.

Directory of Open Access Journals (Sweden)

Rege N

1993-01-01

Full Text Available An in vitro assay technique was set up to determine the phagocytic and microbicidal activity of a monocyte-macrophage cell line using Candida species as test organisms. The norms were determined for the activity of peritoneal macrophages of rats (24.69 +/- 2.6% phagocytosis and 35.4 +/- 5.22% ICK and human (27.89 +/- 3.63% phagocytosis and 50.91 +/- 6.3% ICK. The assay technique was used to test the degree of activation of macrophages induced by metronidazole, Tinospora cordifolia and Asparaqus racemousus and to compare their effects with a standard immunomodulator muramyl-dipeptide. All the three test agents increased the phagocytic and killing capacity of macrophages in a dose dependent manner upto a certain dose, beyond which either these activities were found to have plateaued or decreased. The optimal doses for MDP, Metronidazole, Asparagus racemosus and Tinospora cordifolia were found to be 100 micrograms, 300 mg/kg, 200 mg/kg and 100 mg/kg respectively. Patients with cirrhosis were screened for defects in monocyte function. The depressed monocyte function (20.58 +/- 5% phago and 41.24 +/- 12.19% ICK; P < 0.05 was observed indicating a compromised host defense. The utility of this candidicidal assay in experimental and clinical studies is discussed.

HIV-1 specific IgA detected in vaginal secretions of HIV uninfected women participating in a microbicide trial in Southern Africa are primarily directed toward gp120 and gp140 specificities.

Directory of Open Access Journals (Sweden)

Kelly E Seaton

Full Text Available Many participants in microbicide trials remain uninfected despite ongoing exposure to HIV-1. Determining the emergence and nature of mucosal HIV-specific immune responses in such women is important, since these responses may contribute to protection and could provide insight for the rational design of HIV-1 vaccines.We first conducted a pilot study to compare three sampling devices (Dacron swabs, flocked nylon swabs and Merocel sponges for detection of HIV-1-specific IgG and IgA antibodies in vaginal secretions. IgG antibodies from HIV-1-positive women reacted broadly across the full panel of eight HIV-1 envelope (Env antigens tested, whereas IgA antibodies only reacted to the gp41 subunit. No Env-reactive antibodies were detected in the HIV-negative women. The three sampling devices yielded equal HIV-1-specific antibody titers, as well as total IgG and IgA concentrations. We then tested vaginal Dacron swabs archived from 57 HIV seronegative women who participated in a microbicide efficacy trial in Southern Africa (HPTN 035. We detected vaginal IgA antibodies directed at HIV-1 Env gp120/gp140 in six of these women, and at gp41 in another three women, but did not detect Env-specific IgG antibodies in any women.Vaginal secretions of HIV-1 infected women contained IgG reactivity to a broad range of Env antigens and IgA reactivity to gp41. In contrast, Env-binding antibodies in the vaginal secretions of HIV-1 uninfected women participating in the microbicide trial were restricted to the IgA subtype and were mostly directed at HIV-1 gp120/gp140.

Comparative analysis of aluminum-air battery propulsion systems for passenger vehicles

Science.gov (United States)

Salisbury, J. D.; Behrin, E.; Kong, M. K.; Whisler, D. J.

1980-02-01

Three electric propulsion systems using an aluminum air battery were analyzed and compared to the internal combustion engine (ICE) vehicle. The engine and fuel systems of a representative five passenger highway vehicle were replaced conceptually by each of the three electric propulsion systems. The electrical vehicles were constrained by the computer simulation to be equivalent to the ICE vehicle in range and acceleration performance. The vehicle masses and aluminum consumption rates were then calculated for the electric vehicles and these data were used as figures of merit. The Al-air vehicles analyzed were (1) an Al-air battery only electric vehicle; (2) an Al-air battery combined with a nickel zinc secondary battery for power leveling and regenerative braking; and (3) an Al-air battery combined with a flywheel for power leveling and regenerative braking. All three electric systems compared favorably with the ICE vehicle.

Synergistic activity profile of griffithsin in combination with tenofovir, maraviroc and enfuvirtide against HIV-1 clade C

International Nuclear Information System (INIS)

Ferir, Geoffrey; Palmer, Kenneth E.; Schols, Dominique

2011-01-01

Griffithsin (GRFT) is possibly the most potent anti-HIV peptide found in natural sources. Due to its potent and broad-spectrum antiviral activity and unique safety profile it has great potential as topical microbicide component. Here, we evaluated various combinations of GRFT against HIV-1 clade B and clade C isolates in primary peripheral blood mononuclear cells (PBMCs) and in CD4 + MT-4 cells. In all combinations tested, GRFT showed synergistic activity profile with tenofovir, maraviroc and enfuvirtide based on the median effect principle with combination indices (CI) varying between 0.34 and 0.79 at the calculated EC 95 level. Furthermore, the different glycosylation patterns on the viral envelope of clade B and clade C gp120 had no observable effect on the synergistic interactions. Overall, we can conclude that the evaluated two-drug combination increases their antiviral potency and supports further clinical investigations in pre-exposure prophylaxis for GRFT combinations in the context of HIV-1 clade C infection.

Vehicle State Information Estimation with the Unscented Kalman Filter

Directory of Open Access Journals (Sweden)

Hongbin Ren

2014-01-01

Full Text Available The vehicle state information plays an important role in the vehicle active safety systems; this paper proposed a new concept to estimate the instantaneous vehicle speed, yaw rate, tire forces, and tire kinemics information in real time. The estimator is based on the 3DoF vehicle model combined with the piecewise linear tire model. The estimator is realized using the unscented Kalman filter (UKF, since it is based on the unscented transfer technique and considers high order terms during the measurement and update stage. The numerical simulations are carried out to further investigate the performance of the estimator under high friction and low friction road conditions in the MATLAB/Simulink combined with the Carsim environment. The simulation results are compared with the numerical results from Carsim software, which indicate that UKF can estimate the vehicle state information accurately and in real time; the proposed estimation will provide the necessary and reliable state information to the vehicle controller in the future.

Studies of an extensively axisymmetric rocket based combined cycle (RBCC) engine powered single-stage-to-orbit (SSTO) vehicle

Science.gov (United States)

Foster, Richard W.; Escher, William J. D.; Robinson, John W.

1989-01-01

The present comparative performance study has established that rocket-based combined cycle (RBCC) propulsion systems, when incorporated by essentially axisymmetric SSTO launch vehicle configurations whose conical forebody maximizes both capture-area ratio and total capture area, are capable of furnishing payload-delivery capabilities superior to those of most multistage, all-rocket launchers. Airbreathing thrust augmentation in the rocket-ejector mode of an RBCC powerplant is noted to make a major contribution to final payload capability, by comparison to nonair-augmented rocket engine propulsion systems.

Periodic Heterogeneous Vehicle Routing Problem With Driver Scheduling

Science.gov (United States)

Mardiana Panggabean, Ellis; Mawengkang, Herman; Azis, Zainal; Filia Sari, Rina

2018-01-01

The paper develops a model for the optimal management of logistic delivery of a given commodity. The company has different type of vehicles with different capacity to deliver the commodity for customers. The problem is then called Periodic Heterogeneous Vehicle Routing Problem (PHVRP). The goal is to schedule the deliveries according to feasible combinations of delivery days and to determine the scheduling of fleet and driver and routing policies of the vehicles. The objective is to minimize the sum of the costs of all routes over the planning horizon. We propose a combined approach of heuristic algorithm and exact method to solve the problem.

Experimental and Numerical Analysis of Bridge Response due to Modular Combination Vehicle Systems

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning; Bang, R.

2004-01-01

Articulated vehicles composed of a tractor and a semi-trailer are dominant in international traffic within the EU. Also road trains can be obtained as an extended articulated vehicle by adding a trailer. A dolly carrying a semi-trailer may replace a road train in the same situation. The present...

Connecting plug-in vehicles with green electricity through consumer demand

Science.gov (United States)

Axsen, Jonn; Kurani, Kenneth S.

2013-03-01

The environmental benefits of plug-in electric vehicles (PEVs) increase if the vehicles are powered by electricity from ‘green’ sources such as solar, wind or small-scale hydroelectricity. Here, we explore the potential to build a market that pairs consumer purchases of PEVs with purchases of green electricity. We implement a web-based survey with three US samples defined by vehicle purchases: conventional new vehicle buyers (n = 1064), hybrid vehicle buyers (n = 364) and PEV buyers (n = 74). Respondents state their interest in a PEV as their next vehicle, in purchasing green electricity in one of three ways, i.e., monthly subscription, two-year lease or solar panel purchase, and in combining the two products. Although we find that a link between PEVs and green electricity is not presently strong in the consciousness of most consumers, the combination is attractive to some consumers when presented. Across all three respondent segments, pairing a PEV with a green electricity program increased interest in PEVs—with a 23% demand increase among buyers of conventional vehicles. Overall, about one-third of respondents presently value the combination of a PEV with green electricity; the proportion is much higher among previous HEV and PEV buyers. Respondents’ reported motives for interest in both products and their combination include financial savings (particularly among conventional buyers), concerns about air pollution and the environment, and interest in new technology (particularly among PEV buyers). The results provide guidance regarding policy and marketing strategies to advance PEVs and green electricity demand.

Connecting plug-in vehicles with green electricity through consumer demand

International Nuclear Information System (INIS)

Axsen, Jonn; Kurani, Kenneth S

2013-01-01

The environmental benefits of plug-in electric vehicles (PEVs) increase if the vehicles are powered by electricity from ‘green’ sources such as solar, wind or small-scale hydroelectricity. Here, we explore the potential to build a market that pairs consumer purchases of PEVs with purchases of green electricity. We implement a web-based survey with three US samples defined by vehicle purchases: conventional new vehicle buyers (n = 1064), hybrid vehicle buyers (n = 364) and PEV buyers (n = 74). Respondents state their interest in a PEV as their next vehicle, in purchasing green electricity in one of three ways, i.e., monthly subscription, two-year lease or solar panel purchase, and in combining the two products. Although we find that a link between PEVs and green electricity is not presently strong in the consciousness of most consumers, the combination is attractive to some consumers when presented. Across all three respondent segments, pairing a PEV with a green electricity program increased interest in PEVs—with a 23% demand increase among buyers of conventional vehicles. Overall, about one-third of respondents presently value the combination of a PEV with green electricity; the proportion is much higher among previous HEV and PEV buyers. Respondents’ reported motives for interest in both products and their combination include financial savings (particularly among conventional buyers), concerns about air pollution and the environment, and interest in new technology (particularly among PEV buyers). The results provide guidance regarding policy and marketing strategies to advance PEVs and green electricity demand. (letter)

Energy Efficiency Comparison between Hydraulic Hybrid and Hybrid Electric Vehicles

Directory of Open Access Journals (Sweden)

Jia-Shiun Chen

2015-05-01

Full Text Available Conventional vehicles tend to consume considerable amounts of fuel, which generates exhaust gases and environmental pollution during intermittent driving cycles. Therefore, prospective vehicle designs favor improved exhaust emissions and energy consumption without compromising vehicle performance. Although pure electric vehicles feature high performance and low pollution characteristics, their limitations are their short driving range and high battery costs. Hybrid electric vehicles (HEVs are comparatively environmentally friendly and energy efficient, but cost substantially more compared with conventional vehicles. Hydraulic hybrid vehicles (HHVs are mainly operated using engines, or using alternate combinations of engine and hydraulic power sources while vehicles accelerate. When the hydraulic system accumulator is depleted, the conventional engine reengages; concurrently, brake-regenerated power is recycled and reused by employing hydraulic motor–pump modules in circulation patterns to conserve fuel and recycle brake energy. This study adopted MATLAB Simulink to construct complete HHV and HEV models for backward simulations. New European Driving Cycles were used to determine the changes in fuel economy. The output of power components and the state-of-charge of energy could be retrieved. Varying power component models, energy storage component models, and series or parallel configurations were combined into seven different vehicle configurations: the conventional manual transmission vehicle, series hybrid electric vehicle, series hydraulic hybrid vehicle, parallel hybrid electric vehicle, parallel hydraulic hybrid vehicle, purely electric vehicle, and hydraulic-electric hybrid vehicle. The simulation results show that fuel consumption was 21.80% lower in the series hydraulic hybrid vehicle compared to the series hybrid electric vehicle; additionally, fuel consumption was 3.80% lower in the parallel hybrid electric vehicle compared to the

Combined Optimal Sizing and Control for a Hybrid Tracked Vehicle

Directory of Open Access Journals (Sweden)

Huei Peng

2012-11-01

Full Text Available The optimal sizing and control of a hybrid tracked vehicle is presented and solved in this paper. A driving schedule obtained from field tests is used to represent typical tracked vehicle operations. Dynamics of the diesel engine-permanent magnetic AC synchronous generator set, the lithium-ion battery pack, and the power split between them are modeled and validated through experiments. Two coupled optimizations, one for the plant parameters, forming the outer optimization loop and one for the control strategy, forming the inner optimization loop, are used to achieve minimum fuel consumption under the selected driving schedule. The dynamic programming technique is applied to find the optimal controller in the inner loop while the component parameters are optimized iteratively in the outer loop. The results are analyzed, and the relationship between the key parameters is observed to keep the optimal sizing and control simultaneously.

Tracking of nuclear shipments with automatic vehicle location systems

International Nuclear Information System (INIS)

Colhoun, C.J.K.

1989-01-01

A complete Automatic Vehicle Location System (AVL) consists of three main elements: (1) the location sensor in the vehicle, this device constantly determines the coordinates of the vehicles position; (2) the radio link between vehicle and central base; (3) the data processing and display in the central base. For all three elements there are several solutions. The optimal combination of the different techniques depends on the requirements of the special application

Are women who work in bars, guesthouses and similar facilities a suitable study population for vaginal microbicide trials in Africa?

Directory of Open Access Journals (Sweden)

Andrew Vallely

2010-05-01

Full Text Available A feasibility study was conducted to investigate whether an occupational at-risk cohort of women in Mwanza, Tanzania are a suitable study population for future phase III vaginal microbicide trials.1573 women aged 16-54 y working in traditional and modern bars, restaurants, hotels, guesthouses or as local food-handlers were enrolled at community-based reproductive health clinics, provided specimens for HIV/STI and pregnancy testing, and asked to attend three-monthly clinical follow-up visits for 12-months. HIV positive and negative women were eligible to enter the feasibility study and to receive free reproductive health services at any time. HIV prevalence at baseline was 26.5% (417/1573. HIV incidence among 1156 sero-negative women attending at baseline was 2.9/100PYs. Among 1020 HIV sero-negative, non-pregnant women, HIV incidence was 2.0/100PYs, HSV-2 incidence 12.7/100PYs and pregnancy rate 17.8/100PYs. Retention at three-months was 76.3% (778/1020. Among 771 HIV sero-negative, non-pregnant women attending at three-months, subsequent follow-up at 6, 9 and 12-months was 83.7%, 79.6%, and 72.1% respectively. Older women, those who had not moved home or changed their place of work in the last year, and women working in traditional bars or as local food handlers had the highest re-attendance.Women working in food outlets and recreational facilities in Tanzania and other parts of Africa may be a suitable study population for microbicide and other HIV prevention trials. Effective locally-appropriate strategies to address high pregnancy rates and early losses to follow-up are essential to minimise risk to clinical trials in these settings.

Combined emergency braking and turning of articulated heavy vehicles

OpenAIRE

Morrison, G; Cebon, David

2017-01-01

‘Slip control’ braking has been shown to reduce the emergency stopping distance of an experimental heavy goods vehicle by up to 19%, compared to conventional electronic/anti-lock braking systems (EBS). However, little regard has been given to the impact of slip control braking on the vehicle’s directional dynamics. This paper uses validated computer models to show that slip control could severely degrade directional performance during emergency braking. A modified slip control strategy, ‘atte...

MiniCD4 microbicide prevents HIV infection of human mucosal explants and vaginal transmission of SHIV(162P3 in cynomolgus macaques.

Directory of Open Access Journals (Sweden)

Nathalie Dereuddre-Bosquet

Full Text Available In complement to an effective vaccine, development of potent anti-HIV microbicides remains an important priority. We have previously shown that the miniCD4 M48U1, a functional mimetic of sCD4 presented on a 27 amino-acid stable scaffold, inhibits a broad range of HIV-1 isolates at sub-nanomolar concentrations in cellular models. Here, we report that M48U1 inhibits efficiently HIV-1(Ba-L in human mucosal explants of cervical and colorectal tissues. In vivo efficacy of M48U1 was evaluated in nonhuman primate (NHP model of mucosal challenge with SHIV(162P3 after assessing pharmacokinetics and pharmacodynamics of a miniCD4 gel formulation in sexually matured female cynomolgus macaques. Among 12 females, half were treated with hydroxyethylcellulose-based gel (control, the other half received the same gel containing 3 mg/g of M48U1, one hour before vaginal route challenge with 10 AID(50 of SHIV(162P3. All control animals were infected with a peak plasma viral load of 10(5-10(6 viral RNA (vRNA copies per mL. In animals treated with miniCD4, 5 out of 6 were fully protected from acquisition of infection, as assessed by qRT-PCR for vRNA detection in plasma, qPCR for viral DNA detection in PBMC and lymph node cells. The only infected animal in this group had a delayed peak of viremia of one week. These results demonstrate that M48U1 miniCD4 acts in vivo as a potent entry inhibitor, which may be considered in microbicide developments.

PASSIVE DETECTION OF VEHICLE LOADING

Energy Technology Data Exchange (ETDEWEB)

Garrett, A.

2012-01-03

The Digital Imaging and Remote Sensing Laboratory (DIRS) at the Rochester Institute of Technology, along with the Savannah River National Laboratory is investigating passive methods to quantify vehicle loading. The research described in this paper investigates multiple vehicle indicators including brake temperature, tire temperature, engine temperature, acceleration and deceleration rates, engine acoustics, suspension response, tire deformation and vibrational response. Our investigation into these variables includes building and implementing a sensing system for data collection as well as multiple full-scale vehicle tests. The sensing system includes; infrared video cameras, triaxial accelerometers, microphones, video cameras and thermocouples. The full scale testing includes both a medium size dump truck and a tractor-trailer truck on closed courses with loads spanning the full range of the vehicle's capacity. Statistical analysis of the collected data is used to determine the effectiveness of each of the indicators for characterizing the weight of a vehicle. The final sensing system will monitor multiple load indicators and combine the results to achieve a more accurate measurement than any of the indicators could provide alone.

Passive detection of vehicle loading

Science.gov (United States)

McKay, Troy R.; Salvaggio, Carl; Faulring, Jason W.; Salvaggio, Philip S.; McKeown, Donald M.; Garrett, Alfred J.; Coleman, David H.; Koffman, Larry D.

2012-01-01

The Digital Imaging and Remote Sensing Laboratory (DIRS) at the Rochester Institute of Technology, along with the Savannah River National Laboratory is investigating passive methods to quantify vehicle loading. The research described in this paper investigates multiple vehicle indicators including brake temperature, tire temperature, engine temperature, acceleration and deceleration rates, engine acoustics, suspension response, tire deformation and vibrational response. Our investigation into these variables includes building and implementing a sensing system for data collection as well as multiple full-scale vehicle tests. The sensing system includes; infrared video cameras, triaxial accelerometers, microphones, video cameras and thermocouples. The full scale testing includes both a medium size dump truck and a tractor-trailer truck on closed courses with loads spanning the full range of the vehicle's capacity. Statistical analysis of the collected data is used to determine the effectiveness of each of the indicators for characterizing the weight of a vehicle. The final sensing system will monitor multiple load indicators and combine the results to achieve a more accurate measurement than any of the indicators could provide alone.

Signal processing and control challenges for smart vehicles

Science.gov (United States)

Zhang, Hui; Braun, Simon G.

2017-03-01

Smart phones have changed not only the mobile phone market but also our society during the past few years. Could the next potential intelligent device may be the vehicle? Judging by the visibility, in all media, of the numerous attempts to develop autonomous vehicles, this is certainly one of the logical outcomes. Smart vehicles would be equipped with an advanced operating system such that the vehicles could communicate with others, optimize the operation to reduce fuel consumption and emissions, enhance safety, or even become self-driving. These combined new features of vehicles require instrumentation and hardware developments, fast signal processing/fusion, decision making and online optimization. Meanwhile, the inevitable increasing system complexity would certainly challenges the control unit design.

Should a vehicle fuel economy standard be combined with an economy-wide greenhouse gas emissions constraint? Implications for energy and climate policy in the United States

International Nuclear Information System (INIS)

Karplus, Valerie J.; Paltsev, Sergey; Babiker, Mustafa; Reilly, John M.

2013-01-01

The United States has adopted fuel economy standards that require increases in the on-road efficiency of new passenger vehicles, with the goal of reducing petroleum use and (more recently) greenhouse gas (GHG) emissions. Understanding the cost and effectiveness of fuel economy standards, alone and in combination with economy-wide policies that constrain GHG emissions, is essential to inform coordinated design of future climate and energy policy. We use a computable general equilibrium model, the MIT Emissions Prediction and Policy Analysis (EPPA) model, to investigate the effect of combining a fuel economy standard with an economy-wide GHG emissions constraint in the United States. First, a fuel economy standard is shown to be at least six to fourteen times less cost effective than a price instrument (fuel tax) when targeting an identical reduction in cumulative gasoline use. Second, when combined with a cap-and-trade (CAT) policy, a binding fuel economy standard increases the cost of meeting the GHG emissions constraint by forcing expensive reductions in passenger vehicle gasoline use, displacing more cost-effective abatement opportunities. Third, the impact of adding a fuel economy standard to the CAT policy depends on the availability and cost of abatement opportunities in transport—if advanced biofuels provide a cost-competitive, low carbon alternative to gasoline, the fuel economy standard does not bind and the use of low carbon fuels in passenger vehicles makes a significantly larger contribution to GHG emissions abatement relative to the case when biofuels are not available. This analysis underscores the potentially large costs of a fuel economy standard relative to alternative policies aimed at reducing petroleum use and GHG emissions. It further emphasizes the need to consider sensitivity to vehicle technology and alternative fuel availability and costs as well as economy-wide responses when forecasting the energy, environmental, and economic outcomes of

Vehicle Sideslip Angle Estimation Based on Hybrid Kalman Filter

Directory of Open Access Journals (Sweden)

Jing Li

2016-01-01

Full Text Available Vehicle sideslip angle is essential for active safety control systems. This paper presents a new hybrid Kalman filter to estimate vehicle sideslip angle based on the 3-DoF nonlinear vehicle dynamic model combined with Magic Formula tire model. The hybrid Kalman filter is realized by combining square-root cubature Kalman filter (SCKF, which has quick convergence and numerical stability, with square-root cubature based receding horizon Kalman FIR filter (SCRHKF, which has robustness against model uncertainty and temporary noise. Moreover, SCKF and SCRHKF work in parallel, and the estimation outputs of two filters are merged by interacting multiple model (IMM approach. Experimental results show the accuracy and robustness of the hybrid Kalman filter.

A modified SILCS contraceptive diaphragm for long-term controlled release of the HIV microbicide dapivirine.

Science.gov (United States)

Major, Ian; Boyd, Peter; Kilbourne-Brook, Maggie; Saxon, Gene; Cohen, Jessica; Malcolm, R Karl

2013-07-01

There is considerable interest in developing new multipurpose prevention technologies to address women's reproductive health needs. This study describes an innovative barrier contraceptive device--based on the SILCS diaphragm--that also provides long-term controlled release of the lead candidate anti-HIV microbicide dapivirine. Diaphragm devices comprising various dapivirine-loaded polymer spring cores overmolded with a nonmedicated silicone elastomer sheath were fabricated by injection molding processes. In vitro release testing, thermal analysis and mechanical characterization were performed on the devices. A diaphragm device containing a polyoxymethylene spring core loaded with 10% w/w dapivirine provided continuous and controlled release of dapivirine over a 6-month period, with a mean in vitro daily release rate of 174 mcg/day. The mechanical properties of the new diaphragm were closely matched to the SILCS diaphragm. The study demonstrates proof of concept for a dapivirine-releasing diaphragm with daily release quantities potentially capable of preventing HIV transmission. In discontinuous clinical use, release of dapivirine may be readily extended over 1 or more years. Copyright © 2013 Elsevier Inc. All rights reserved.

Supercavitating Vehicle Control

National Research Council Canada - National Science Library

Kuklinski, Robert

2008-01-01

.... The segmented ring wing is controlled by a ring actuator. The ring actuator may be used to control the angle of attack of the ring wing. Alternately, or in combination the flow over the ring wing may be neutralized by using the cavitator of the vehicle to globally enlarge the cavity and thus limit the flow.

Reverse Transcriptase Inhibitors as Potential Colorectal Microbicides▿ †

Science.gov (United States)

Herrera, Carolina; Cranage, Martin; McGowan, Ian; Anton, Peter; Shattock, Robin J.

2009-01-01

We investigated whether reverse transcriptase (RT) inhibitors (RTI) can be combined to inhibit human immunodeficiency virus type 1 (HIV-1) infection of colorectal tissue ex vivo as part of a strategy to develop an effective rectal microbicide. The nucleotide RTI (NRTI) PMPA (tenofovir) and two nonnucleoside RTI (NNRTI), UC-781 and TMC120 (dapivirine), were evaluated. Each compound inhibited the replication of the HIV isolates tested in TZM-bl cells, peripheral blood mononuclear cells, and colorectal explants. Dual combinations of the three compounds, either NRTI-NNRTI or NNRTI-NNRTI combinations, were more active than any of the individual compounds in both cellular and tissue models. Combinations were key to inhibiting infection by NRTI- and NNRTI-resistant isolates in all models tested. Moreover, we found that the replication capacities of HIV-1 isolates in colorectal explants were affected by single point mutations in RT that confer resistance to RTI. These data demonstrate that colorectal explants can be used to screen compounds for potential efficacy as part of a combination microbicide and to determine the mucosal fitness of RTI-resistant isolates. These findings may have important implications for the rational design of effective rectal microbicides. PMID:19258271

Estimating GHG Reduction from Combinations of Current Best-Available and Future Powertrain and Vehicle Technologies for a Midsized Car Using EPA’s ALPHA Model (SAE 2016-01-0910)

Science.gov (United States)

EPA identified the best, or most efficient, engines, transmissions and vehicle technologies, and then used ALPHA to predict the GHG emissions would be from a midsized car incorporating the best combination of these technologies.

A Novel Vehicle Classification Using Embedded Strain Gauge Sensors

Directory of Open Access Journals (Sweden)

Qi Wang

2008-11-01

Full Text Available Abstract: This paper presents a new vehicle classification and develops a traffic monitoring detector to provide reliable vehicle classification to aid traffic management systems. The basic principle of this approach is based on measuring the dynamic strain caused by vehicles across pavement to obtain the corresponding vehicle parameters – wheelbase and number of axles – to then accurately classify the vehicle. A system prototype with five embedded strain sensors was developed to validate the accuracy and effectiveness of the classification method. According to the special arrangement of the sensors and the different time a vehicle arrived at the sensors one can estimate the vehicle’s speed accurately, corresponding to the estimated vehicle wheelbase and number of axles. Because of measurement errors and vehicle characteristics, there is a lot of overlap between vehicle wheelbase patterns. Therefore, directly setting up a fixed threshold for vehicle classification often leads to low-accuracy results. Using the machine learning pattern recognition method to deal with this problem is believed as one of the most effective tools. In this study, support vector machines (SVMs were used to integrate the classification features extracted from the strain sensors to automatically classify vehicles into five types, ranging from small vehicles to combination trucks, along the lines of the Federal Highway Administration vehicle classification guide. Test bench and field experiments will be introduced in this paper. Two support vector machines classification algorithms (one-against-all, one-against-one are used to classify single sensor data and multiple sensor combination data. Comparison of the two classification method results shows that the classification accuracy is very close using single data or multiple data. Our results indicate that using multiclass SVM-based fusion multiple sensor data significantly improves

Improving work zone safety for freight vehicles : effective design patterns for vehicle mounted attenuators.

Science.gov (United States)

2010-12-01

This report presents a study of driver perceptions using a driving simulator carried out on the effectiveness of : four markings which vary in striping patterns and color combinations used at the rear of vehicle mounted : attenuators (VMAs) in work z...

Combinatorial Approaches to the Prevention and Treatment of HIV-1 Infection▿†

Science.gov (United States)

Pirrone, Vanessa; Thakkar, Nina; Jacobson, Jeffrey M.; Wigdahl, Brian; Krebs, Fred C.

2011-01-01

The discovery of the human immunodeficiency virus type 1 (HIV-1) in 1982 soon led to the identification and development of antiviral compounds to be used in treatment strategies for infected patients. Early in the epidemic, drug monotherapies frequently led to treatment failures because the virus quickly developed resistance to the single drug. Following the advent of highly active antiretroviral therapy (HAART) in 1995, dramatic improvements in HIV-1-infected patient health and survival were realized as more refined combination therapies resulted in reductions in viral loads and increases in CD4+ T-cell counts. In the absence of an effective vaccine, prevention of HIV-1 infection has also gained traction as an approach to curbing the pandemic. The development of compounds as safe and effective microbicides has intensified and has focused on blocking the transmission of HIV-1 during all forms of sexual intercourse. Initial preclinical investigations and clinical trials of microbicides focused on single compounds effective against HIV-1. However, the remarkable successes achieved using combination therapy to treat systemic HIV-1 infection have subsequently stimulated the study and development of combination microbicides that will simultaneously inhibit multiple aspects of the HIV-1 transmission process by targeting incoming viral particles, virus-infected cells, and cells susceptible to HIV-1 infection. This review focuses on existing and developing combination therapies, covering preclinical development, in vitro and in vivo efficacy studies, and subsequent clinical trials. The shift in focus within the microbicide development field from single compounds to combination approaches is also explored. PMID:21343462

Thrombin-induced rabbit platelet microbicidal protein is fungicidal in vitro.

Science.gov (United States)

Yeaman, M R; Ibrahim, A S; Edwards, J E; Bayer, A S; Ghannoum, M A

1993-03-01

Platelet microbicidal protein (PMP) is released from platelets in response to thrombin stimulation. PMP is known to possess in vitro bactericidal activity against Staphylococcus aureus and viridans group streptococci. To determine whether PMP is active against other intravascular pathogens, we evaluated its potential fungicidal activity against strains of Candida species and Cryptococcus neoformans. Anionic resin adsorption and gel electrophoresis confirmed that the fungicidal activity of PMP resided in a small (approximately 8.5-kDa), cationic protein, identical to previous studies of PMP-induced bacterial killing (M.R. Yeaman, S.M. Puentes, D.C. Norman, and A.S. Bayer, Infect. Immun. 60:1202-1209, 1992). When assayed over a 180-min period in vitro, the susceptibilities of these fungi to PMP varied considerably. Generally, Candida albicans strains (mean survival, 33.5% +/- 6.9% [n = 6]) as well as isolates of Candida glabrata (mean survival, 50.8% +/- 2.9% [n = 2]) were the most susceptible to killing by PMP, while Candida guillermondii and Candida parapsilosis were relatively resistant to PMP-induced killing. Compared with C. albicans, C. neoformans was relatively resistant to the fungicidal activity of PMP, with a mean survival among the isolates studied of 77.4% +/- 12.4% (n = 6). Against C. albicans, PMP-induced fungicidal activity was time dependent (range, 0 to 180 min), PMP concentration dependent (range, 10 to 150 U/ml), and inversely related to the fungal inoculum (range, 5 x 10(3) to 1 x 10(5) CFU/ml). Scanning electron microscopy of PMP-exposed C. albicans and C. neoformans cells revealed extensive surface damage and collapse, suggesting that the site of PMP fungicidal action may directly or indirectly involve the fungal cell envelope.

Intelligent behaviors through vehicle-to-vehicle and vehicle-to-infrastructure communication

Science.gov (United States)

Garcia, Richard D.; Sturgeon, Purser; Brown, Mike

2012-06-01

The last decade has seen a significant increase in intelligent safety devices on private automobiles. These devices have both increased and augmented the situational awareness of the driver and in some cases provided automated vehicle responses. To date almost all intelligent safety devices have relied on data directly perceived by the vehicle. This constraint has a direct impact on the types of solutions available to the vehicle. In an effort to improve the safety options available to a vehicle, numerous research laboratories and government agencies are investing time and resources into connecting vehicles to each other and to infrastructure-based devices. This work details several efforts in both the commercial vehicle and the private auto industries to increase vehicle safety and driver situational awareness through vehicle-to-vehicle and vehicle-to-infrastructure communication. It will specifically discuss intelligent behaviors being designed to automatically disable non-compliant vehicles, warn tractor trailer vehicles of unsafe lane maneuvers such as lane changes, passing, and merging, and alert drivers to non-line-of-sight emergencies.

The Effects of a Rectangular Rapid-Flashing Beacon on Vehicle Speed

Science.gov (United States)

VanWagner, Michelle; Van Houten, Ron; Betts, Brian

2011-01-01

In 2008, nearly 31% of vehicle fatalities were related to failure to adhere to safe vehicle speeds (National Highway Traffic Safety Administration [NHTSA], 2009). The current study evaluated the effect of a rectangular rapid-flashing beacon (RRFB) triggered by excessive speed on vehicle speed using a combined alternating treatments and reversal…

A Combination of Genetic Algorithm and Particle Swarm Optimization for Vehicle Routing Problem with Time Windows.

Science.gov (United States)

Xu, Sheng-Hua; Liu, Ji-Ping; Zhang, Fu-Hao; Wang, Liang; Sun, Li-Jian

2015-08-27

A combination of genetic algorithm and particle swarm optimization (PSO) for vehicle routing problems with time windows (VRPTW) is proposed in this paper. The improvements of the proposed algorithm include: using the particle real number encoding method to decode the route to alleviate the computation burden, applying a linear decreasing function based on the number of the iterations to provide balance between global and local exploration abilities, and integrating with the crossover operator of genetic algorithm to avoid the premature convergence and the local minimum. The experimental results show that the proposed algorithm is not only more efficient and competitive with other published results but can also obtain more optimal solutions for solving the VRPTW issue. One new well-known solution for this benchmark problem is also outlined in the following.

Assessment of future natural gas vehicle concepts

Science.gov (United States)

Groten, B.; Arrigotti, S.

1992-10-01

The development of Natural Gas Vehicles is progressing rapidly under the stimulus of recent vehicle emission regulations. The development is following what can be viewed as a three step progression. In the first step, contemporary gasoline or diesel fueled automobiles are retrofitted with equipment enabling the vehicle to operate on either natural gas or standard liquid fuels. The second step is the development of vehicles which utilize traditional internal combustion engines that have been modified to operate exclusively on natural gas. These dedicated natural gas vehicles operate more efficiently and have lower emissions than the dual fueled vehicles. The third step is the redesigning, from the ground up, of a vehicle aimed at exploiting the advantages of natural gas as an automotive fuel while minimizing its disadvantages. The current report is aimed at identifying the R&D needs in various fuel storage and engine combinations which have potential for providing increased efficiency, reduced emissions, and reductions in vehicle weight and size. Fuel suppliers, automobile and engine manufacturers, many segments of the natural gas and other industries, and regulatory authorities will influence or be affected by the development of such a third generation vehicle, and it is recommended that GRI act to bring these groups together in the near future to begin, developing the focus on a 'designed-for-natural-gas' vehicle.

Advanced protection technology for ground combat vehicles.

Science.gov (United States)

Bosse, Timothy G

2012-01-01

Just as highway drivers use radar detectors to attempt to stay ahead of police armed with the latest radar technology, the Armed Forces are locked in a spiral to protect combat vehicles and their crews against the latest threats in both the contemporary operating environment and the anticipated operating environment (ie, beyond 2020). In response to bigger, heavier, or better-protected vehicles, adversaries build and deploy larger explosive devices or bombs. However, making improvements to combat vehicles is much more expensive than deploying larger explosives. In addition, demand is increasing for lighter-weight vehicles capable of rapid deployment. Together, these two facts give the threat a clear advantage in the future. To protect vehicles and crews, technologies focusing on detection and hit avoidance, denial of penetration, and crew survivability must be combined synergistically to provide the best chance of survival on the modern battlefield.

USING OF NON-CONVENTIONAL FUELS IN HYBRID VEHICLE DRIVES

Directory of Open Access Journals (Sweden)

Dalibor Barta

2016-12-01

Full Text Available Electric or hybrid vehicles are becoming increasingly common on roads. While electric vehicles are still more or less intended for city traffic, hybrid vehicles allow normal use due to wider driving range. The use of internal combustion engines in hybrid drives is still an inspiration to find the way to reduce the produc-tion of emissions. Numbers of alternative energy resources were studied as a substitution of conventional fuels for hybrid vehicles drives worldwide. The paper deals with the possibility of using alternative fuels as CNG, LPG and LNG in combination with hybrid drive of a midibus with the capacity of 20 passengers. Various aspects and techniques of hybrid vehicles from energy management system, propulsion system and using of various alternative fuels are explored in this paper. Other related fields of hybrid vehicles such as changes of vehicle weight or influence of electric energy sources on the total vehicle emission production are also included.

Compatibility of booster seats and vehicles in the U.S. market.

Science.gov (United States)

Bing, Julie A; Agnew, Amanda M; Bolte, John H

2018-05-19

The objective of this study was to analyze booster and rear vehicle seat dimensions to identify the most frequent compatibility problems. Measurements were collected from 40 high-back and backless boosters and 95 left rear and center rear row seating positions in 50 modern vehicles. Dimensions were compared for 3,800 booster/vehicle seat combinations. For validation and estimation of tolerance and correction factors, 72 booster installations were physically completed and compared with measurement-based compatibility predictions. Dimensions were also compared to the International Organization for Standardization (ISO) volumetric envelopes of forward-facing child restraints and boosters. Seat belt buckles in outboard positions accommodated the width of boosters better than center positions (success rates of 85.4 and 34.7%, respectively). Adequate head restraint clearance occurred in 71.9 to 77.2% of combinations, depending on the booster's head support setting. Booster recline angles aligned properly with vehicle seat cushion angles in 71.5% of combinations. In cases of poor angle alignment, booster angles were more obtuse than the vehicle seat angles 97.7% of the time. Head restraint interference exacerbated angle alignment issues. Data indicate success rates above 90% for boosters being fully supported by the length of the seat cushion and for adequate height clearance with the vehicle roofline. Comparison to ISO envelopes indicates that most boosters on the U.S. market are taller and angled more obtusely than ISO target envelopes. This study quantifies some of the common interferences between boosters and vehicles that may complicate booster usage. Data are useful for design and to prioritize specific problem areas.

Pregnant women's attitudes about topical microbicides for the prevention and treatment of bacterial vaginosis during pregnancy.

Science.gov (United States)

Catallozzi, Marina; Fraiz, Lauren Dapena; Hargreaves, Katharine M; Zimet, Gregory D; Stanberry, Lawrence R; Ratner, Adam J; Gelber, Shari E; Rosenthal, Susan L

2017-08-01

We sought to understand pregnant women's product preference and likelihood of use of topical microbicides for bacterial vaginosis (BV) prevention and treatment. Pregnant women (N = 196) in a obstetrics clinic completed a survey between June 2014 and January 2015 about vaginal product use for BV. This cross-sectional study explored product preferences, likelihood of product use for BV management and father of the baby (FOB) involvement. Most participants were under 30 (68%) and underrepresented minorities (47% Hispanic, 21% African-American). Most women preferred the gel (69%). Only 30% were likely to use either product for prevention of BV; 76% if high risk for BV; 83% treatment of BV. Anticipated FOB involvement in decision-making included that 46% would ask his opinion, 38% would inform him of the decision and 7% would need approval. Most (87%) would ask the FOB for reminders and 66% for insertion help. Those under 30 were more likely to agree to ask the FOB for reminders (p Product preferences may be less critical than risk perception. Involvement of the FOB in decision-making may be vital.

Electric and hybrid vehicle environmental control subsystem study

Science.gov (United States)

Heitner, K. L.

1980-01-01

An environmental control subsystem (ECS) in electric and hybrid vehicles is studied. A combination of a combustion heater and gasoline engine (Otto cycle) driven vapor compression air conditioner is selected. The combustion heater, the small gasoline engine, and the vapor compression air conditioner are commercially available. These technologies have good cost and performance characteristics. The cost for this ECS is relatively close to the cost of current ECS's. Its effect on the vehicle's propulsion battery is minimal and the ECS size and weight do not have significant impact on the vehicle's range.

Optimal Isolation Control of Three-Port Active Converters as a Combined Charger for Electric Vehicles

Directory of Open Access Journals (Sweden)

Zhixiang Ling

2016-09-01

Full Text Available The three-port converter has three H-bridge ports that can interface with three different energy sources and offers the advantages of flexible power transmission, galvanic isolation ability and high power density. The three-port full-bridge converter can be used in electric vehicles as a combined charger that consists of a battery charger and a DC-DC converter. Power transfer occurs between two ports while the third port is isolated, i.e., the average power is zero. The purpose of this paper is to apply an optimal phase shift strategy in isolation control and provide a detailed comparison between traditional phase shift control and optimal phase shift control under the proposed isolation control scheme, including comparison of the zero-voltage-switching range and the root mean square current for the two methods. Based on this analysis, the optimal parameters are selected. The results of simulations and experiments are given to verify the advantages of dual-phase-shift control in isolation control.

Integrated vehicle control and guidance systems in unmanned ground vehicles for commercial applications

Science.gov (United States)

Kenyon, Chase H.

1995-01-01

While there is a lot of recent development in the entire IVHS field, very few have had the opportunity to combine the many areas of development into a single integrated `intelligent' unmanned vehicle. One of our systems was developed specifically to serve a major automobile manufacturer's need for an automated vehicle chassis durability test facility. Due to the severity of the road surface human drivers could not be used. A totally automated robotic vehicle driver and guidance system was necessary. In order to deliver fixed price commercial projects now, it was apparent system and component costs were of paramount importance. Cyplex has developed a robust, cost effective single wire guidance system. This system has inherent advantages in system simplicity. Multi-signal (per vehicle lane) systems complicate path planning and layout when multiple lanes and lane changes are required, as on actual highways. The system has demonstrated high enough immunity to rain and light snow cover that normal safety reductions in speed are adequate to stay within the required system performance envelope. This system and it's antenna interface have shown the ability to guide the vehicle at slow speeds (10 MPH) with a tracking repeatability of plus or minus 1/8 of an inch. The basic guide and antenna system has been tested at speeds up to 80 mph. The system has inherently superior abilities for lane changes and precision vehicle placement. The operation of this system will be described and the impact of a system that is commercially viable now for highway and off road use will be discussed.

Improving the large scale purification of the HIV microbicide, griffithsin.

Science.gov (United States)

Fuqua, Joshua L; Wanga, Valentine; Palmer, Kenneth E

2015-02-22

Griffithsin is a broad spectrum antiviral lectin that inhibits viral entry and maturation processes through binding clusters of oligomannose glycans on viral envelope glycoproteins. An efficient, scaleable manufacturing process for griffithsin active pharmaceutical ingredient (API) is essential for particularly cost-sensitive products such as griffithsin -based topical microbicides for HIV-1 prevention in resource poor settings. Our previously published purification method used ceramic filtration followed by two chromatography steps, resulting in a protein recovery of 30%. Our objective was to develop a scalable purification method for griffithsin expressed in Nicotiana benthamiana plants that would increase yield, reduce production costs, and simplify manufacturing techniques. Considering the future need to transfer griffithsin manufacturing technology to resource poor areas, we chose to focus modifying the purification process, paying particular attention to introducing simple, low-cost, and scalable procedures such as use of temperature, pH, ion concentration, and filtration to enhance product recovery. We achieved >99% pure griffithsin API by generating the initial green juice extract in pH 4 buffer, heating the extract to 55°C, incubating overnight with a bentonite MgCl2 mixture, and final purification with Capto™ multimodal chromatography. Griffithsin extracted with this protocol maintains activity comparable to griffithsin purified by the previously published method and we are able to recover a substantially higher yield: 88 ± 5% of griffithsin from the initial extract. The method was scaled to produce gram quantities of griffithsin with high yields, low endotoxin levels, and low purification costs maintained. The methodology developed to purify griffithsin introduces and develops multiple tools for purification of recombinant proteins from plants at an industrial scale. These tools allow for robust cost-effective production and purification of

Conceptual shape optimization of entry vehicles applied to capsules and winged fuselage vehicles

CERN Document Server

Dirkx, Dominic

2017-01-01

This book covers the parameterization of entry capsules, including Apollo capsules and planetary probes, and winged entry vehicles such as the Space Shuttle and lifting bodies. The aerodynamic modelling is based on a variety of panel methods that take shadowing into account, and it has been validated with flight and wind tunnel data of Apollo and the Space Shuttle. The shape optimization is combined with constrained trajectory analysis, and the multi-objective approach provides the engineer with a Pareto front of optimal shapes. The method detailed in Conceptual Shape Optimization of Entry Vehicles is straightforward, and the output gives the engineer insight in the effect of shape variations on trajectory performance. All applied models and algorithms used are explained in detail, allowing for reconstructing the design tool to the researcher’s requirements. Conceptual Shape Optimization of Entry Vehicles will be of interest to both researchers and graduate students in the field of aerospace engineering, an...

Blast mines: physics, injury mechanisms and vehicle protection.

Science.gov (United States)

Ramasamy, A; Hill, A M; Hepper, A E; Bull, A M J; Clasper, J C

2009-12-01

Since World War II, more vehicles have been lost to land mines than all other threats combined. Anti-vehicular (AV) mines are capable of disabling a heavy vehicle, or completely destroying a lighter vehicle. The most common form of AV mine is the blast mine, which uses a large amount of explosive to directly damage the target. In a conventional military setting, landmines are used as a defensive force-multiplier and to restrict the movements of the opposing force. They are relatively cheap to purchase and easy to acquire, hence landmines are also potent weapons in the insurgents' armamentarium. The stand-offnature of its design has allowed insurgents to cause significant injuries to security forces in current conflicts with little personal risk. As a result, AV mines and improvised explosive devices (IEDs) have become the most common cause of death and injury to Coalition and local security forces operating in Iraq and Afghanistan. Detonation of an AV mine causes an explosive, exothermic reaction which results in the formation of a shockwave followed by a rapid expansion of gases. The shockwave is mainly reflected by the soillair interface and fractures the soil cap overthe mine. The detonation products then vent through the voids in the soil, resulting in a hollow inverse cone which consists of the detonation gases surrounded by the soil ejecta. It is the combination of the detonation products and soil ejecta that interact with the target vehicle and cause injury to the vehicle occupants. A number of different strategies are required to mitigate the blast effects of an explosion. Primary blast effects can be reduced by increasing the standoff distance between the seat of the explosion and the crew compartment. Enhancement of armour on the base of the vehicle, as well as improvements in personal protection can prevent penetration of fragments. Mitigating tertiary effects can be achieved by altering the vehicle geometry and structure, increasing vehicle mass, as

The commercialization of natural gas for vehicles

International Nuclear Information System (INIS)

Wray, P.

1997-01-01

A successful NGV industry depends upon the skilled use of prime geographic and economic drivers. But a vital ingredient to a sustained and profitable industry is the pioneering example of the gas suppliers and the combined commercial skills of fleet operators equipment suppliers and government. The use of natural gas for vehicles must be long-term commercially viable both for the vehicles whole life cost and the refuelling stations capital investment. (au)

Hybrid vehicles - an alternative for the Swedish market; Hybridfordon - ett alternativ foer den svenska bilparken

Energy Technology Data Exchange (ETDEWEB)

Egebaeck, Karl-Erik; Bucksch, S

2000-06-01

The object of this report is to assemble information on and describe the situation for the development of hybrid vehicles and various alternatives within this field of development. In the report the description is concentrated mainly on the combination of combustion engine and electric battery, which is the most common combination in present day hybrid vehicles. In order to take a glimpse into the future even the combination of fuel cells and electric battery is described. The light duty electric hybrid vehicles which have been developed up to now are mainly parallel hybrids. If the development of hybrid systems takes place it will most certainly concern light duty vehicles which will come to be parallel hybrids equipped with an Otto or a diesel engine, depending on what the manufacturers wish to back. In the report the use of series hybrid vehicles is estimated to be limited to heavy-duty hybrid vehicles. Hybrids will not be likely to be relevant for heavy-duty vehicles, with the exception of those lorries which operate in city centres, i.e. lorries which are used to distribute goods to shops, garbage vehicles and certain types of working vehicle for service purposes. Continued development of the hybrid system for buses seems uncertain for various reasons. If there is a technical breakthrough in the manufacture of batteries and simultaneously the manufacturers increase their efforts to develop hybrid vehicles, the situation can be changed so that there is a speedier introduction of hybrid vehicles for heavy-duty vehicles.

Hybrid vehicle assessment. Phase 1: Petroleum savings analysis

Science.gov (United States)

Levin, R.; Liddle, S.; Deshpande, G.; Trummel, M.; Vivian, H. C.

1984-01-01

The results of a comprehensive analysis of near term electric hybrid vehicles are presented, with emphasis on their potential to save significant amounts of petroleum on a national scale in the 1990s. Performance requirements and expected annual usage patterns of these vehicles are first modeled. The projected U.S. fleet composition is estimated, and conceptual hybrid vehicle designs are conceived and analyzed for petroleum use when driven in the expected annual patterns. These petroleum consumption estimates are then compared to similar estimates for projected 1990 conventional vehicles having the same performance and driven in the same patterns. Results are presented in the form of three utility functions and comparisons of sevral conceptual designs are made. The Hybrid Vehicle (HV) design and assessment techniques are discussed and a general method is explained for selecting the optimum energy management strategy for any vehicle mission battery combination. Conclusions and recommendations are presented, and development recommendations are identified.

Hybrid vehicle assessment. Phase I. Petroleum savings analysis

Energy Technology Data Exchange (ETDEWEB)

Levin, R.; Liddle, S.; Deshpande, G.; Trummel, M.; Vivian, H.

1984-03-01

This report presents the results of a comprehensive analysis of near-term electric-hybrid vehicles. Its purpose was to estimate their potential to save significant amounts of petroleum on a national scale in the 1990s. Performance requirements and expected annual usage patterns of these vehicles were first modeled. The projected US fleet composition was estimated, and conceptual hybrid vehicle designs were conceived and analyzed for petroleum use when driven in the expected annual patterns. These petroleum consumption estimates were then compared to similar estimates for projected 1990 conventional vehicles having the same performance and driven in the same patterns. Results are presented in the form of three utility functions and comparisons of several conceptual designs are made. The Hybrid Vehicle (HV) design and assessment techniques are discussed and a general method is explained for selecting the optimum energy management strategy for any vehicle-mission-battery combination. A discussion of lessons learned during the construction and test of the General Electric Hybrid Test Vehicle is also presented. Conclusions and recommendations are presented, and development recommendations are identified.

Lifecycle-analysis for heavy vehicles

International Nuclear Information System (INIS)

Gaines, L.

1998-01-01

Various alternative fuels and improved engine and vehicle systems have been proposed in order to reduce emissions and energy use associated with heavy vehicles (predominantly trucks). For example, oil companies have proposed improved methods for converting natural gas to zero-aromatics, zero-sulfur diesel fuel via the Fischer-Tropsch process. Major heavy-duty diesel engine companies are working on ways to simultaneously reduce particulate-matter and NOX emissions. The trend in heavy vehicles is toward use of lightweight materials, tires with lower rolling resistance, and treatments to reduce aerodynamic drag. In this paper, we compare the Mecycle energy use and emissions from trucks using selected alternatives, such as Fisher-Tropsch diesel fuel and advanced fuel-efficient engines. We consider heavy-duty, Class 8 tractor-semitrailer combinations for this analysis. The total life cycle includes production and recycling of the vehicle itself, extraction, processing, and transportation of the fuel itself, and vehicle operation and maintenance. Energy use is considered in toto, as well as those portions that are imported, domestic, and renewable. Emissions of interest include greenhouse gases and criteria pollutants. Angonne's Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model is used to generate per-vehicle fuel cycle impacts. Energy use and emissions for materials manufacturing and vehicle disposal are estimated by means of materials information from Argonne studies. We conclude that there are trade-offs among impacts. For example, the lowest fossil energy use does not necessarily result in lowest total energy use, and lower tailpipe emissions may not necessarily result in lower lifecycle emissions of all criteria pollutants

Vehicles instability criteria for flood risk assessment of a street network

Directory of Open Access Journals (Sweden)

C. Arrighi

2016-05-01

Full Text Available The mutual interaction between floods and human activity is a process, which has been evolving over history and has shaped flood risk pathways. In developed countries, many events have illustrated that the majority of the fatalities during a flood occurs in a vehicle, which is considered as a safe shelter but it may turn into a trap for several combinations of water depth and velocity. Thus, driving a car in floodwaters is recognized as the most crucial aggravating factor for people safety. On the other hand, the entrainment of vehicles may locally cause obstructions to the flow and induce the collapse of infrastructures. Flood risk to vehicles can be defined as the combination of the probability of a vehicle of being swept away (i.e. the hazard and the actual traffic/parking density, i.e. the vulnerability. Hazard for vehicles can be assessed through the spatial identification and mapping of the critical conditions for vehicles incipient motion. This analysis requires a flood map with information on water depth and velocity and consistent instability criteria accounting for flood and vehicles characteristics. Vulnerability is evaluated thanks to the road network and traffic data. Therefore, vehicles flood risk mapping can support people's education and management practices in order to reduce the casualties. In this work, a flood hazard classification for vehicles is introduced and an application to a real case study is presented and discussed.

Vehicles instability criteria for flood risk assessment of a street network

Science.gov (United States)

Arrighi, Chiara; Huybrechts, Nicolas; Ouahsine, Abdellatif; Chassé, Patrick; Oumeraci, Hocine; Castelli, Fabio

2016-05-01

The mutual interaction between floods and human activity is a process, which has been evolving over history and has shaped flood risk pathways. In developed countries, many events have illustrated that the majority of the fatalities during a flood occurs in a vehicle, which is considered as a safe shelter but it may turn into a trap for several combinations of water depth and velocity. Thus, driving a car in floodwaters is recognized as the most crucial aggravating factor for people safety. On the other hand, the entrainment of vehicles may locally cause obstructions to the flow and induce the collapse of infrastructures. Flood risk to vehicles can be defined as the combination of the probability of a vehicle of being swept away (i.e. the hazard) and the actual traffic/parking density, i.e. the vulnerability. Hazard for vehicles can be assessed through the spatial identification and mapping of the critical conditions for vehicles incipient motion. This analysis requires a flood map with information on water depth and velocity and consistent instability criteria accounting for flood and vehicles characteristics. Vulnerability is evaluated thanks to the road network and traffic data. Therefore, vehicles flood risk mapping can support people's education and management practices in order to reduce the casualties. In this work, a flood hazard classification for vehicles is introduced and an application to a real case study is presented and discussed.

ELECTROMAGNETIC BIOSPHERE POLLUTION BY MOTOR TRANSPORT (VEHICLES, ELECTRIC VEHICLES, HYBRID VEHICLES

Directory of Open Access Journals (Sweden)

S. Selivanov

2009-01-01

Full Text Available The physics of the electromagnetic field is considered. The analysis of electromagnetic radiation on the human-being, the origin of which is the vehicle the electric vehicle, the hybrid vehicle is being considered. The monitoring of electromagnetic radiation of vehicles is carried out.

Performance evaluation and design of flight vehicle control systems

CERN Document Server

Falangas, Eric T

2015-01-01

This book will help students, control engineers and flight dynamics analysts to model and conduct sophisticated and systemic analyses of early flight vehicle designs controlled with multiple types of effectors and to design and evaluate new vehicle concepts in terms of satisfying mission and performance goals. Performance Evaluation and Design of Flight Vehicle Control Systems begins by creating a dynamic model of a generic flight vehicle that includes a range of elements from airplanes and launch vehicles to re-entry vehicles and spacecraft. The models may include dynamic effects dealing with structural flexibility, as well as dynamic coupling between structures and actuators, propellant sloshing, and aeroelasticity, and they are typically used for control analysis and design. The book shows how to efficiently combine different types of effectors together, such as aero-surfaces, TVC, throttling engines and RCS, to operate as a system by developing a mixing logic atrix. Methods of trimming a vehicle controll...

Obtaining valid laboratory data in clinical trials conducted in resource diverse settings: lessons learned from a microbicide phase III clinical trial.

Directory of Open Access Journals (Sweden)

Tania Crucitti

2010-10-01

Full Text Available Over the last decade several phase III microbicides trials have been conducted in developing countries. However, laboratories in resource constrained settings do not always have the experience, infrastructure, and the capacity to deliver laboratory data meeting the high standards of clinical trials. This paper describes the design and outcomes of a laboratory quality assurance program which was implemented during a phase III clinical trial evaluating the efficacy of the candidate microbicide Cellulose Sulfate 6% (CS [1].In order to assess the effectiveness of CS for HIV and STI prevention, a phase III clinical trial was conducted in 5 sites: 3 in Africa and 2 in India. The trial sponsor identified an International Central Reference Laboratory (ICRL, responsible for the design and management of a quality assurance program, which would guarantee the reliability of laboratory data. The ICRL provided advice on the tests, assessed local laboratories, organized trainings, conducted supervision visits, performed re-tests, and prepared control panels. Local laboratories were provided with control panels for HIV rapid tests and Chlamydia trachomatis/Neisseria gonorrhoeae (CT/NG amplification technique. Aliquots from respective control panels were tested by local laboratories and were compared with results obtained at the ICRL.Overall, good results were observed. However, discordances between the ICRL and site laboratories were identified for HIV and CT/NG results. One particular site experienced difficulties with HIV rapid testing shortly after study initiation. At all sites, DNA contamination was identified as a cause of invalid CT/NG results. Both problems were timely detected and solved. Through immediate feedback, guidance and repeated training of laboratory staff, additional inaccuracies were prevented.Quality control guidelines when applied in field laboratories ensured the reliability and validity of final study data. It is essential that sponsors

Regardless-of-Speed Superconducting LSM Controlled-Repulsive MAGLEV Vehicle

Science.gov (United States)

Yoshida, Kinjiro; Egashira, Tatsuya; Hirai, Ryuichi

1996-01-01

This paper proposes a new repulsive Maglev vehicle which a superconducting linear synchronous motor (LSM) can levitate and propel simultaneously, independently of the vehicle speeds. The combined levitation and propulsion control is carried out by controlling mechanical-load angle and armature-current. Dynamic simulations show successful operations with good ride-quality by using a compact control method proposed here.

Evaluation of the lateral dynamics of complex articulated commercial vehicles

NARCIS (Netherlands)

Besselink, I.J.M.; Isiklar, G.; Pinxteren, van T.E.L.; Nijmeijer, H.

2008-01-01

By increasing the overall length and weight of commercial vehicles, the transport efficiency and road utilization will be improved and the C02 emissions can be reduced by some 30%. Over the past years experiments are carried out in the Netherlands with special vehicle combinations having an overall

Emissions control techniques applied to industrial vehicles

Energy Technology Data Exchange (ETDEWEB)

Martin, B.

2004-12-15

As emission standards for industrial vehicles become increasingly stringent, many research projects are seeking to develop after-treatment systems. These systems will have to combine efficiency, durability and low operating cost.

A Range-Based Vehicle Life Cycle Assessment Incorporating Variability in the Environmental Assessment of Different Vehicle Technologies and Fuels

Directory of Open Access Journals (Sweden)

Maarten Messagie

2014-03-01

Full Text Available How to compare the environmental performance of different vehicle technologies? Vehicles with lower tailpipe emissions are perceived as cleaner. However, does it make sense to look only to tailpipe emissions? Limiting the comparison only to these emissions denies the fact that there are emissions involved during the production of a fuel and this approach gives too much advantage to zero-tailpipe vehicles like battery electric vehicles (BEV and fuel cell electric vehicle (FCEV. Would it be enough to combine fuel production and tailpipe emissions? Especially when comparing the environmental performance of alternative vehicle technologies, the emissions during production of the specific components and their appropriate end-of-life treatment processes should also be taken into account. Therefore, the complete life cycle of the vehicle should be included in order to avoid problem shifting from one life stage to another. In this article, a full life cycle assessment (LCA of petrol, diesel, fuel cell electric (FCEV, compressed natural gas (CNG, liquefied petroleum gas (LPG, hybrid electric, battery electric (BEV, bio-diesel and bio-ethanol vehicles has been performed. The aim of the manuscript is to investigate the impact of the different vehicle technologies on the environment and to develop a range-based modeling system that enables a more robust interpretation of the LCA results for a group of vehicles. Results are shown for climate change, respiratory effects, acidification and mineral extraction damage of the different vehicle technologies. A broad range of results is obtained due to the variability within the car market. It is concluded that it is essential to take into account the influence of all the vehicle parameters on the LCA results.

Vehicle barrier with access delay

Science.gov (United States)

Swahlan, David J; Wilke, Jason

2013-09-03

An access delay vehicle barrier for stopping unauthorized entry into secure areas by a vehicle ramming attack includes access delay features for preventing and/or delaying an adversary from defeating or compromising the barrier. A horizontally deployed barrier member can include an exterior steel casing, an interior steel reinforcing member and access delay members disposed within the casing and between the casing and the interior reinforcing member. Access delay members can include wooden structural lumber, concrete and/or polymeric members that in combination with the exterior casing and interior reinforcing member act cooperatively to impair an adversarial attach by thermal, mechanical and/or explosive tools.

Driving cycle suitable layout of permanent magnet synchronous machines for hybrid vehicles and electric powered vehicles; Fahrzyklusgerechte Auslegung von permanentmagneterregten Synchronmaschinen fuer Hybrid- und Elektrofahrzeuge

Energy Technology Data Exchange (ETDEWEB)

Finken, Thomas

2011-07-01

An increasing environmental awareness and the prospect of a shortage of fossil resources will result in a development of efficient vehicles with a lower consumption of fuel. In addition to the hybrid electric vehicle, the electric powered vehicle increasingly is focused in the development of vehicles. A good efficiency is the most important demand on the electrical machine. The author of the book under consideration reports on exemplary operating point distributions for various vehicle concepts and user profiles. After comparing the most common types of machine in terms of the use in electrified powertrains, the permanent magnet synchronous machine is selected and discussed in detail. A table shows the advantages and disadvantages of all considered geometries and variations. Thus, a suitable combination of geometry for a given vehicle concept and its requirements are selected.

Vehicle-manipulator systems modeling for simulation, analysis, and control

CERN Document Server

From, Pal Johan; Pettersen, Kristin Ytterstad

2014-01-01

Furthering the aim of reducing human exposure to hazardous environments, this monograph presents a detailed study of the modeling and control of vehicle-manipulator systems. The text shows how complex interactions can be performed at remote locations using systems that combine the manipulability of robotic manipulators with the ability of mobile robots to locomote over large areas.  The first part studies the kinematics and dynamics of rigid bodies and standard robotic manipulators and can be used as an introduction to robotics focussing on robust mathematical modeling. The monograph then moves on to study vehicle-manipulator systems in great detail with emphasis on combining two different configuration spaces in a mathematically sound way. Robustness of these systems is extremely important and Modeling and Control of Vehicle-manipulator Systems effectively represents the dynamic equations using a mathematically robust framework. Several tools from Lie theory and differential geometry are used to obtain glob...

Remotely detected vehicle mass from engine torque-induced frame twisting

Science.gov (United States)

McKay, Troy R.; Salvaggio, Carl; Faulring, Jason W.; Sweeney, Glenn D.

2017-06-01

Determining the mass of a vehicle from ground-based passive sensor data is important for many traffic safety requirements. This work presents a method for calculating the mass of a vehicle using ground-based video and acoustic measurements. By assuming that no energy is lost in the conversion, the mass of a vehicle can be calculated from the rotational energy generated by the vehicle's engine and the linear acceleration of the vehicle over a period of time. The amount of rotational energy being output by the vehicle's engine can be calculated from its torque and angular velocity. This model relates remotely observed, engine torque-induced frame twist to engine torque output using the vehicle's suspension parameters and engine geometry. The angular velocity of the engine is extracted from the acoustic emission of the engine, and the linear acceleration of the vehicle is calculated by remotely observing the position of the vehicle over time. This method combines these three dynamic signals; engine induced-frame twist, engine angular velocity, and the vehicle's linear acceleration, and three vehicle specific scalar parameters, into an expression that describes the mass of the vehicle. This method was tested on a semitrailer truck, and the results demonstrate a correlation of 97.7% between calculated and true vehicle mass.

Manitoba plug-in hybrid electric vehicle (PHEV) demonstration

Energy Technology Data Exchange (ETDEWEB)

Hoemsen, R. [Red River College, Winnipeg, MB (Canada); Parsons, R. [Government of Manitoba, Winnipeg, MB (Canada). Centre for Emerging Renewable Energy

2010-07-01

Manitoba has low electricity rates, the highest proportion of renewables, and a legislated commitment to reduce greenhouse gases. However, the province still relies heavily on oil as everyone else. The mix of energy opportunities in Manitoba were highlighted in this presentation, with particular reference to the commercialization of electric vehicles. Several photographs were presented of the Toyota plug-in hybrid vehicle and a plug-in hybrid electric demonstration vehicle. A demonstration project overview was offered that used technology from A123 Systems Inc. The conversion module and vehicle users were profiled. Topics that were presented related to the demonstration project included monitoring; gasoline fuel economy results; fuel economy variability; cold weather operation; cold weather issues; battery upgrade solutions; and highly qualified personnel. It was concluded that in terms of follow-up, there is a need to combine findings of current plug-in hybrid electric vehicle demonstration with those for the new Toyota production plug-in hybrid vehicles. Key next steps for the demonstration are to address cabin heating requirements; better characterizing winter performance; and implementation of IPLC units on all plug-in hybrid electric vehicles for electricity consumption. figs.

The clinical impact of vehicle technology using a patented formulation of benzoyl peroxide 5%/clindamycin 1% gel: comparative assessments of skin tolerability and evaluation of combination use with a topical retinoid.

Science.gov (United States)

Del Rosso, James Q; Tanghetti, Emil

2006-02-01

A major challenge encountered in clinical practice in patients with acne vulgaris is irritation related to topical medications used for treatment. Advances in vehicle technology have improved formulations containing active ingredients known to produce irritation in some patients, such as benzoyl peroxide (BP) and topical retinoids. Clinical studies, including combination therapy studies have demonstrated that certain additives, such as silicates and specific humectants, reduce irritation by maintaining barrier integrity. A patented gel formulation of BP 5%/clindamycin phosphate 1% (clindamycin) containing dimethicone and glycerin has been studied both as a monotherapy and in combination with topical retinoid use. This article evaluates specific vehicle additives included in this gel formulation and explains their role in reducing irritation. Data from clinical trials utilizing this technology in acne management are also reviewed.

Release of Tenofovir from Carrageenan-Based Vaginal Suppositories

Directory of Open Access Journals (Sweden)

Toral Zaveri

2014-07-01

Full Text Available Microbicides are an active area of research for HIV prevention, being developed as a woman-initiated method of prevention during unprotected coitus. Along with safety and efficacy, assessing and improving compliance is a major area of research in microbicide development. We have produced microbicide prototypes in the form of semisoft vaginal suppositories prepared from carrageenan and conducted both qualitative and quantitative studies using these prototypes to determine the physical properties that drive acceptability and possibly adherence. In order to ensure that the suppositories function as effective drug delivery vehicles, we have conducted in vitro dissolution studies in water, vaginal simulant fluid (VSF and semen simulant fluid (SSF with suppositories loaded with the antiretroviral drug, tenofovir (TFV. TFV was released via diffusion and matrix erosion in water or by diffusion out of the matrix in VSF and SSF. Diffusion studies were conducted in two different volumes of VSF and SSF. The volume of VSF/SSF into which TFV diffused and the size of the suppositories determined the rate of diffusion from the suppositories. About 45%–50% of the encapsulated TFV diffused out of the suppositories within the first two hours, irrespective of suppository size, diffusion medium (VSF/SSF and the volume of medium. Prior work indicates that a short waiting period between insertion and coitus is highly desired by women; present data suggest our microbicide prototypes have rapid initial release followed by a slow release curve over the first 24 h.

Advances in fuel cell vehicle design

Science.gov (United States)

Bauman, Jennifer

Factors such as global warming, dwindling fossil fuel reserves, and energy security concerns combine to indicate that a replacement for the internal combustion engine (ICE) vehicle is needed. Fuel cell vehicles have the potential to address the problems surrounding the ICE vehicle without imposing any significant restrictions on vehicle performance, driving range, or refuelling time. Though there are currently some obstacles to overcome before attaining the widespread commercialization of fuel cell vehicles, such as improvements in fuel cell and battery durability, development of a hydrogen infrastructure, and reduction of high costs, the fundamental concept of the fuel cell vehicle is strong: it is efficient, emits zero harmful emissions, and the hydrogen fuel can be produced from various renewable sources. Therefore, research on fuel cell vehicle design is imperative in order to improve vehicle performance and durability, increase efficiency, and reduce costs. This thesis makes a number of key contributions to the advancement of fuel cell vehicle design within two main research areas: powertrain design and DC/DC converters. With regards to powertrain design, this research first analyzes various powertrain topologies and energy storage system types. Then, a novel fuel cell-battery-ultracapacitor topology is presented which shows reduced mass and cost, and increased efficiency, over other promising topologies found in the literature. A detailed vehicle simulator is created in MATLAB/Simulink in order to simulate and compare the novel topology with other fuel cell vehicle powertrain options. A parametric study is performed to optimize each powertrain and general conclusions for optimal topologies, as well as component types and sizes, for fuel cell vehicles are presented. Next, an analytical method to optimize the novel battery-ultracapacitor energy storage system based on maximizing efficiency, and minimizing cost and mass, is developed. This method can be applied

Accelerated Lane-Changing Trajectory Planning of Automated Vehicles with Vehicle-to-Vehicle Collaboration

Directory of Open Access Journals (Sweden)

Haijian Bai

2017-01-01

Full Text Available Considering the complexity of lane changing using automated vehicles and the frequency of turning lanes in city settings, this paper aims to generate an accelerated lane-changing trajectory using vehicle-to-vehicle collaboration (V2VC. Based on the characteristics of accelerated lane changing, we used a polynomial method and cooperative strategies for trajectory planning to establish a lane-changing model under different degrees of collaboration with the following vehicle in the target lane by considering vehicle kinematics and comfort requirements. Furthermore, considering the shortcomings of the traditional elliptical vehicle and round vehicle models, we established a rectangular vehicle model with collision boundary conditions by analysing the relationships between the possible collision points and the outline of the vehicle. Then, we established a simulation model for the accelerated lane-changing process in different environments under different degrees of collaboration. The results show that, by using V2VC, we can achieve safe accelerated lane-changing trajectories and simultaneously satisfy the requirements of vehicle kinematics and comfort control.

Current challenges in autonomous vehicle development

Science.gov (United States)

Connelly, J.; Hong, W. S.; Mahoney, R. B., Jr.; Sparrow, D. A.

2006-05-01

The field of autonomous vehicles is a rapidly growing one, with significant interest from both government and industry sectors. Autonomous vehicles represent the intersection of artificial intelligence (AI) and robotics, combining decision-making with real-time control. Autonomous vehicles are desired for use in search and rescue, urban reconnaissance, mine detonation, supply convoys, and more. The general adage is to use robots for anything dull, dirty, dangerous or dumb. While a great deal of research has been done on autonomous systems, there are only a handful of fielded examples incorporating machine autonomy beyond the level of teleoperation, especially in outdoor/complex environments. In an attempt to assess and understand the current state of the art in autonomous vehicle development, a few areas where unsolved problems remain became clear. This paper outlines those areas and provides suggestions for the focus of science and technology research. The first step in evaluating the current state of autonomous vehicle development was to develop a definition of autonomy. A number of autonomy level classification systems were reviewed. The resulting working definitions and classification schemes used by the authors are summarized in the opening sections of the paper. The remainder of the report discusses current approaches and challenges in decision-making and real-time control for autonomous vehicles. Suggested research focus areas for near-, mid-, and long-term development are also presented.

Heavy-duty diesel vehicles dominate vehicle emissions in a tunnel study in northern China.

Science.gov (United States)

Song, Congbo; Ma, Chao; Zhang, Yanjie; Wang, Ting; Wu, Lin; Wang, Peng; Liu, Yan; Li, Qian; Zhang, Jinsheng; Dai, Qili; Zou, Chao; Sun, Luna; Mao, Hongjun

2018-05-09

The relative importance of contributions of gasoline vehicles (GVs) and diesel vehicles (DVs), heavy-duty diesel vehicles (HDDVs) and non-HDDVs to on-road vehicle emissions remains unclear. Vehicle emission factors (EFs), including fine particulate matter (PM 2.5 ), NO-NO 2 -NO x , and carbon monoxide (CO), were measured (August 4-18, 2017) in an urban tunnel in Tianjin, northern China. The average EFs (mg km -1 veh -1 ) of the fleet were as follows: 9.21 (95% confidence interval: 1.60, 23.07) for PM 2.5 , 62.08 (21.21, 138.25) for NO, 20.42 (0.79, 45.48) for NO 2 , 83.72 (26.29, 162.87) for NO x , and 284.54 (18.22, 564.67) for CO. The fleet-average EFs exhibited diurnal variations, due to diurnal variations in the proportion of HDDVs in the fleet, though the hourly proportion of HDDVs never exceeded 10% during the study period. The reconstructed average EFs for on-road vehicle emissions of PM 2.5 , NO, NO 2 , and NO x , and CO were approximately 2.2, 1.7, 1.5, 2.0, and 1.6 times as much as those in the tunnel, respectively, due to the higher HDDV fractions in the whole city than those in the tunnel. The EFs of PM 2.5 , NO, NO 2 , and NO x , and CO from each HDDV were approximately 75, 81, 24, 65, and 33 times of those from each non-HDDV, respectively. HDDVs were responsible for approximately 81.92%, 83.02%, 59.79%, 79.79%, and 66.77% of the total PM 2.5 , NO, NO 2 , and NO x , and CO emissions from on-road vehicles in Tianjin, respectively. DVs, especially HDDVs, are major sources of on-road PM 2.5 , NO-NO 2 -NO x , and CO emissions in northern China. The contribution of HDDVs to fleet emissions calculated by the EFs from Chinese 'on-road vehicle emission inventory guidebook' were underestimated, as compared to our results. The EFs from on-road vehicles should be updated due to the rapid progression of vehicle technology combined with emission standards in China. The management and control of HDDV emissions have become urgent to reduction of on-road vehicle

A Vehicle Active Safety Model: Vehicle Speed Control Based on Driver Vigilance Detection Using Wearable EEG and Sparse Representation.

Science.gov (United States)

Zhang, Zutao; Luo, Dianyuan; Rasim, Yagubov; Li, Yanjun; Meng, Guanjun; Xu, Jian; Wang, Chunbai

2016-02-19

In this paper, we present a vehicle active safety model for vehicle speed control based on driver vigilance detection using low-cost, comfortable, wearable electroencephalographic (EEG) sensors and sparse representation. The proposed system consists of three main steps, namely wireless wearable EEG collection, driver vigilance detection, and vehicle speed control strategy. First of all, a homemade low-cost comfortable wearable brain-computer interface (BCI) system with eight channels is designed for collecting the driver's EEG signal. Second, wavelet de-noising and down-sample algorithms are utilized to enhance the quality of EEG data, and Fast Fourier Transformation (FFT) is adopted to extract the EEG power spectrum density (PSD). In this step, sparse representation classification combined with k-singular value decomposition (KSVD) is firstly introduced in PSD to estimate the driver's vigilance level. Finally, a novel safety strategy of vehicle speed control, which controls the electronic throttle opening and automatic braking after driver fatigue detection using the above method, is presented to avoid serious collisions and traffic accidents. The simulation and practical testing results demonstrate the feasibility of the vehicle active safety model.

Experiments in teleoperator and autonomous control of space robotic vehicles

Science.gov (United States)

Alexander, Harold L.

1991-01-01

A program of research embracing teleoperator and automatic navigational control of freely flying satellite robots is presented. Current research goals include: (1) developing visual operator interfaces for improved vehicle teleoperation; (2) determining the effects of different visual interface system designs on operator performance; and (3) achieving autonomous vision-based vehicle navigation and control. This research program combines virtual-environment teleoperation studies and neutral-buoyancy experiments using a space-robot simulator vehicle currently under development. Visual-interface design options under investigation include monoscopic versus stereoscopic displays and cameras, helmet-mounted versus panel-mounted display monitors, head-tracking versus fixed or manually steerable remote cameras, and the provision of vehicle-fixed visual cues, or markers, in the remote scene for improved sensing of vehicle position, orientation, and motion.

Multi-Disciplinary Design Optimization of Hypersonic Air-Breathing Vehicle

Science.gov (United States)

Wu, Peng; Tang, Zhili; Sheng, Jianda

2016-06-01

A 2D hypersonic vehicle shape with an idealized scramjet is designed at a cruise regime: Mach number (Ma) = 8.0, Angle of attack (AOA) = 0 deg and altitude (H) = 30kms. Then a multi-objective design optimization of the 2D vehicle is carried out by using a Pareto Non-dominated Sorting Genetic Algorithm II (NSGA-II). In the optimization process, the flow around the air-breathing vehicle is simulated by inviscid Euler equations using FLUENT software and the combustion in the combustor is modeled by a methodology based on the well known combination effects of area-varying pipe flow and heat transfer pipe flow. Optimization results reveal tradeoffs among total pressure recovery coefficient of forebody, lift to drag ratio of vehicle, specific impulse of scramjet engine and the maximum temperature on the surface of vehicle.

A probabilistic approach to combining smart meter and electric vehicle charging data to investigate distribution network impacts

International Nuclear Information System (INIS)

Neaimeh, Myriam; Wardle, Robin; Jenkins, Andrew M.; Yi, Jialiang; Hill, Graeme; Lyons, Padraig F.; Hübner, Yvonne; Blythe, Phil T.; Taylor, Phil C.

2015-01-01

Highlights: • Working with unique datasets of EV charging and smart meter load demand. • Distribution networks are not a homogenous group with more capabilities to accommodate EVs than previously suggested. • Spatial and temporal diversity of EV charging demand alleviate the impacts on networks. • An extensive recharging infrastructure could enable connection of additional EVs on constrained distribution networks. • Electric utilities could increase the network capability to accommodate EVs by investing in recharging infrastructure. - Abstract: This work uses a probabilistic method to combine two unique datasets of real world electric vehicle charging profiles and residential smart meter load demand. The data was used to study the impact of the uptake of Electric Vehicles (EVs) on electricity distribution networks. Two real networks representing an urban and rural area, and a generic network representative of a heavily loaded UK distribution network were used. The findings show that distribution networks are not a homogeneous group with a variation of capabilities to accommodate EVs and there is a greater capability than previous studies have suggested. Consideration of the spatial and temporal diversity of EV charging demand has been demonstrated to reduce the estimated impacts on the distribution networks. It is suggested that distribution network operators could collaborate with new market players, such as charging infrastructure operators, to support the roll out of an extensive charging infrastructure in a way that makes the network more robust; create more opportunities for demand side management; and reduce planning uncertainties associated with the stochastic nature of EV charging demand.

Revolutionizing our roadways : the challenges and benefits of making automated vehicles a reality.

Science.gov (United States)

2014-02-01

Automated vehicles (AVs)a combination of technologies and sensors that : enable vehicles to operate with limited or no driver inputare rapidly moving : from science fiction to real-world application. Low-level, limited function AV : technologie...

HSA/PSS coated gold nanorods as thermo-triggered drug delivery vehicles for combined cancer photothermal therapy and chemotherapy

Science.gov (United States)

Tu, Ting-Yu; Yang, Shu-Jyuan; Wang, Chung-Hao; Lee, Shin-Yu; Shieh, Ming-Jium

2018-02-01

Drug delivery systems combined multimodal therapy strategies are very promising in cancer theranostic applications. In this work, a new drug-delivery vehicles based on human serum albumin (HSA)-coated gold nanorods (GNR/PSS/HSA NPs) was developed. The success of coating was verified by transmission electron microscopy (TEM), zeta potential and fourier transform infrared spectroscopy (FTIR). Furthermore, it is demonstrated that doxorubicin (DOX) is successfully loaded among multilayered gold nanorods by the electrostatic and hydrophobic force, and DOX@GNR/PSS/HSA NPs were highly biocompatible and stable in various physiological solutions. The NPs possess strong absorbance in nearinfrared (NIR) region, and high photothermal conversion efficiency for outstanding photothermal therapy applications. A bimodal drug release triggered by proteinase or NIR irradiation has been revealed, resulting in a significant chemotherapeutic effect in tumor sites because of the preferential drug accumulation and triggered release. Importantly, the in vitro and in vivo experiments demonstrated that DOX@GNR/PSS/HSA NPs, which combined photothermal and chemotherapy for cancer therapy, revealing a remarkably superior synergistic anticancer effect over either monotherapy. All these results suggested a considerable potential of DOX@GNR/PSS/HSA NPs nano-platform for antitumor therapy.

Effects of vehicle power on passenger vehicle speeds.

Science.gov (United States)

McCartt, Anne T; Hu, Wen

2017-07-04

During the past 2 decades, there have been large increases in mean horsepower and the mean horsepower-to-vehicle weight ratio for all types of new passenger vehicles in the United States. This study examined the relationship between travel speeds and vehicle power, defined as horsepower per 100 pounds of vehicle weight. Speed cameras measured travel speeds and photographed license plates and drivers of passenger vehicles traveling on roadways in Northern Virginia during daytime off-peak hours in spring 2013. The driver licensing agencies in the District of Columbia, Maryland, and Virginia provided vehicle information numbers (VINs) by matching license plate numbers with vehicle registration records and provided the age, gender, and ZIP code of the registered owner(s). VINs were decoded to obtain the curb weight and horsepower of vehicles. The study focused on 26,659 observed vehicles for which information on horsepower was available and the observed age and gender of drivers matched vehicle registration records. Log-linear regression estimated the effects of vehicle power on mean travel speeds, and logistic regression estimated the effects of vehicle power on the likelihood of a vehicle traveling over the speed limit and more than 10 mph over the limit. After controlling for driver characteristics, speed limit, vehicle type, and traffic volume, a 1-unit increase in vehicle power was associated with a 0.7% increase in mean speed, a 2.7% increase in the likelihood of a vehicle exceeding the speed limit by any amount, and an 11.6% increase in the likelihood of a vehicle exceeding the limit by 10 mph. All of these increases were highly significant. Speeding persists as a major factor in crashes in the United States. There are indications that travel speeds have increased in recent years. The current findings suggest the trend toward substantially more powerful vehicles may be contributing to higher speeds. Given the strong association between travel speed and crash

Estimated combined steady state tyre slip characteristics

NARCIS (Netherlands)

Fernandez, A.L.A.; Pauwelussen, J.P.

2001-01-01

Excessive behaviour of vehicles is often the subject of study, motivated by either the development of active safety systems uch as ESP, or the improvement of vehicle performance such as for racecars. In all of these cases, combined slip needs to be taken into account. In many cases however, the full

Safety problems in vehicles with adaptive cruise control system

Directory of Open Access Journals (Sweden)

Yadav Arun K.

2017-06-01

Full Text Available In today’s world automotive industries are still putting efforts towards more autonomous vehicles (AVs. The main concern of introducing the autonomous technology is safety of driver. According to a survey 90% of accidents happen due to mistake of driver. The adaptive cruise control system (ACC is a system which combines cruise control with a collision avoidance system. The ACC system is based on laser and radar technologies. This system is capable of controlling the velocity of vehicle automatically to match the velocity of car, bus or truck in front of vehicle. If the lead vehicle gets slow down or accelerate, than ACC system automatically matches that velocity. The proposed paper is focusing on more accurate methods of detecting the preceding vehicle by using a radar and lidar sensors by considering the vehicle side slip and by controlling the distance between two vehicles. By using this approach i.e. logic for calculation of former vehicle distance and controlling the throttle valve of ACC equipped vehicle, an improvement in driving stability was achieved. The own contribution results with fuel efficient driving and with more safer and reliable driving system, but still some improvements are going on to make it more safe and reliable.

Dynamics of a railway vehicle on a laterally disturbed track

DEFF Research Database (Denmark)

Christiansen, Lasse Engbo; True, Hans

2017-01-01

In this article a theoretical investigation of the dynamics of a railway bogie running on a tangent track with a periodic disturbance of the lateral track geometry is presented. The dynamics is computed for two values of the speed of the vehicle in combination with different values of the wavelen......In this article a theoretical investigation of the dynamics of a railway bogie running on a tangent track with a periodic disturbance of the lateral track geometry is presented. The dynamics is computed for two values of the speed of the vehicle in combination with different values...

In Vitro Cross-Resistance Profiles of Rilpivirine, Dapivirine, and MIV-150, Nonnucleoside Reverse Transcriptase Inhibitor Microbicides in Clinical Development for the Prevention of HIV-1 Infection.

Science.gov (United States)

Giacobbi, Nicholas S; Sluis-Cremer, Nicolas

2017-07-01

Rilpivirine (RPV), dapivirine (DPV), and MIV-150 are in development as microbicides. It is not known whether they will block infection of circulating nonnucleoside reverse transcriptase inhibitor (NNRTI)-resistant human immunodeficiency virus type 1 (HIV-1) variants. Here, we demonstrate that the activity of DPV and MIV-150 is compromised by many resistant viruses containing single or double substitutions. High DPV genital tract concentrations from DPV ring use may block replication of resistant viruses. However, MIV-150 genital tract concentrations may be insufficient to inhibit many resistant viruses, including those harboring K103N or Y181C. Copyright © 2017 American Society for Microbiology.

Electric vehicle equipment for grid-integrated vehicles

Science.gov (United States)

Kempton, Willett

2013-08-13

Methods, systems, and apparatus for interfacing an electric vehicle with an electric power grid are disclosed. An exemplary apparatus may include a station communication port for interfacing with electric vehicle station equipment (EVSE), a vehicle communication port for interfacing with a vehicle management system (VMS), and a processor coupled to the station communication port and the vehicle communication port to establish communication with the EVSE via the station communication port, receive EVSE attributes from the EVSE, and issue commands to the VMS to manage power flow between the electric vehicle and the EVSE based on the EVSE attributes. An electric vehicle may interface with the grid by establishing communication with the EVSE, receiving the EVSE attributes, and managing power flow between the EVE and the grid based on the EVSE attributes.

System for cooling hybrid vehicle electronics, method for cooling hybrid vehicle electronics

Science.gov (United States)

France, David M.; Yu, Wenhua; Singh, Dileep; Zhao, Weihuan

2017-11-21

The invention provides a single radiator cooling system for use in hybrid electric vehicles, the system comprising a surface in thermal communication with electronics, and subcooled boiling fluid contacting the surface. The invention also provides a single radiator method for simultaneously cooling electronics and an internal combustion engine in a hybrid electric vehicle, the method comprising separating a coolant fluid into a first portion and a second portion; directing the first portion to the electronics and the second portion to the internal combustion engine for a time sufficient to maintain the temperature of the electronics at or below 175.degree. C.; combining the first and second portion to reestablish the coolant fluid; and treating the reestablished coolant fluid to the single radiator for a time sufficient to decrease the temperature of the reestablished coolant fluid to the temperature it had before separation.

Making the case for direct hydrogen storage in fuel cell vehicles

Energy Technology Data Exchange (ETDEWEB)

James, B.D.; Thomas, C.E.; Baum, G.N.; Lomas, F.D. Jr.; Kuhn, I.F. Jr. [Directed Technologies, Inc., Arlington, VA (United States)

1997-12-31

Three obstacles to the introduction of direct hydrogen fuel cell vehicles are often states: (1) inadequate onboard hydrogen storage leading to limited vehicle range; (2) lack of an hydrogen infrastructure, and (3) cost of the entire fuel cell system. This paper will address the first point with analysis of the problem/proposed solutions for the remaining two obstacles addressed in other papers. Results of a recent study conducted by Directed Technologies Inc. will be briefly presented. The study, as part of Ford Motor Company/DOE PEM Fuel Cell Program, examines multiple pure hydrogen onboard storage systems on the basis of weight, volume, cost, and complexity. Compressed gas, liquid, carbon adsorption, and metal hydride storage are all examined with compressed hydrogen storage at 5,000 psia being judged the lowest-risk, highest benefit, near-term option. These results are combined with recent fuel cell vehicle drive cycle simulations to estimate the onboard hydrogen storage requirement for full vehicle range (380 miles on the combined Federal driving schedule). The results indicate that a PNGV-like vehicle using powertrain weights and performance realistically available by the 2004 PNGV target data can achieve approximate fuel economy equivalent to 100 mpg on gasoline (100 mpg{sub eq}) and requires storage of approximately 3.6 kg hydrogen for full vehicle storage quantity allows 5,000 psia onboard storage without altering the vehicle exterior lines or appreciably encroaching on the passenger or trunk compartments.

Perceptions among Dutch men who have sex with men and their willingness to use rectal microbicides and oral pre-exposure prophylaxis to reduce HIV risk--a preliminary study.

Science.gov (United States)

Marra, Elske; Hankins, Catherine A

2015-01-01

Oral pre-exposure prophylaxis (PrEP) with antiretroviral (ARV) tablets and topical PrEP or microbicides containing ARV drugs could help to reduce HIV incidence. These methods hold promise for men who have sex with men (MSM) who are at higher risk of acquiring HIV. This mixed-methods study in the Netherlands explored perceptions of MSM and their willingness to use oral PrEP and rectal microbicides (RM) if made available. Recruited through social media (Facebook and Twitter), 108 MSM completed online questionnaires. Seven of them consented to discuss the survey results in semi-structured interviews. Survey participants preferred a RM that could be applied before and after anal intercourse (60.8%) to daily oral PrEP (20.3%). This preference was based on anticipated user friendliness, hypothetically fewer expected adverse events, and perceptions that RM would be less likely to be confused with ARVs for treatment. Those who preferred oral PrEP had stronger beliefs in the effectiveness of pills, perceived its use as easy, and viewed not requiring sexual partner awareness as advantages. No predictive factors were found for the choice of one prevention method over the other. Although Dutch MSM perceive both oral and topical PrEP positively, many barriers exist to the introduction of these products in the Netherlands. These include lack of regulatory approval of oral PrEP, no proven efficacy as yet for RM, and strong HIV stigma within the MSM population. In-depth qualitative research is needed to further explore the perceptions of MSM to inform implementation of programmes should these HIV prevention methods become available.

Analysis of Vehicle Steering and Driving Bifurcation Characteristics

Directory of Open Access Journals (Sweden)

Xianbin Wang

2015-01-01

Full Text Available The typical method of vehicle steering bifurcation analysis is based on the nonlinear autonomous vehicle model deriving from the classic two degrees of freedom (2DOF linear vehicle model. This method usually neglects the driving effect on steering bifurcation characteristics. However, in the steering and driving combined conditions, the tyre under different driving conditions can provide different lateral force. The steering bifurcation mechanism without the driving effect is not able to fully reveal the vehicle steering and driving bifurcation characteristics. Aiming at the aforementioned problem, this paper analyzed the vehicle steering and driving bifurcation characteristics with the consideration of driving effect. Based on the 5DOF vehicle system dynamics model with the consideration of driving effect, the 7DOF autonomous system model was established. The vehicle steering and driving bifurcation dynamic characteristics were analyzed with different driving mode and driving torque. Taking the front-wheel-drive system as an example, the dynamic evolution process of steering and driving bifurcation was analyzed by phase space, system state variables, power spectral density, and Lyapunov index. The numerical recognition results of chaos were also provided. The research results show that the driving mode and driving torque have the obvious effect on steering and driving bifurcation characteristics.

Analysis of four-stroke, Wankel, and microturbine based range extenders for electric vehicles

International Nuclear Information System (INIS)

Ribau, João; Silva, Carla; Brito, Francisco P.; Martins, Jorge

2012-01-01

Highlights: ► VSP correlates well with the engine use, regenerative braking and boost setting. ► Wankel engine vehicle is the most efficient in urban driving. ► Over-expanded engine vehicle is the most efficient in annual combined use. ► The higher the annual urban commuting driving the lower is energy consumption. ► Over-expanded solution has 5.7% WTW less energy usage and 8.8% less CO 2 emissions. - Abstract: This paper aims to compare the energy efficiency and CO 2 emissions of four different range extender engine solutions deployed in the same baseline series hybrid vehicle, under a combination of driving scenarios aiming to be representative of typical driving instead of standard cycles. Baseline vehicle is roughly based on Chevy VOLT/Opel Ampera. The baseline internal combustion engine is replaced by an over-expanded cycle engine, Wankel engine and microturbine, with respective generator and exhaust after treatment. Weight savings are compensated by introducing additional battery modules, maintaining the original baseline vehicle curb weight. Vehicle Specific Power (VSP) is used for driving cycle analysis and as explanatory variable for energy consumption and CO 2 emissions variations. Upstream fuel energy and CO 2 emissions of gasoline/diesel and electricity are regarded. Average VSP correlates with variation of the percentage of engine off, potential regenerative braking energy and eco/boost operation. Positive wheel energy correlates with energy consumption and electric autonomy adequately. The vehicle with the lightest engine (Wankel) and largest battery shows to be the most efficient in urban driving (when the engine does not have to work), while the vehicle with the highest efficient engine (over-expanded) and with dual eco/boost setting is the most efficient during the charge sustaining operation and in annual combined use.

Integrating a hydrogen fuel cell electric vehicle with vehicle-to-grid technology, photovoltaic power and a residential building

NARCIS (Netherlands)

Robledo, C.B.; Oldenbroek, V.D.W.M.; Abbruzzese, F.; van Wijk, A.J.M.

2018-01-01

This paper presents the results of a demonstration project, including building-integrated photovoltaic (BIPV) solar panels, a residential building and a hydrogen fuel cell electric vehicle (FCEV) for combined mobility and power generation, aiming to achieve a net zero-energy residential building

Mucosal integrity and inflammatory markers in the female lower genital tract as potential screening tools for vaginal microbicides.

Science.gov (United States)

Su, H Irene; Schreiber, Courtney A; Fay, Courtney; Parry, Sam; Elovitz, Michal A; Zhang, Jian; Shaunik, Alka; Barnhart, Kurt

2011-11-01

In the female genital tract, vaginal colposcopy, endometrial mucosal integrity and inflammatory mediators are potential in vivo biomarkers of microbicide and contraceptive safety. A randomized, blinded crossover trial of 18 subjects comparing effects of nonoxynol-9 vaginal gel (Gynol II; putative inflammatory gel), hydroxyethyl cellulose gel (HEC; putative inert gel) and no gel exposure on endometrial and vaginal epithelial integrity and endometrial and vaginal inflammatory markers [interleukin (IL) 1β, IL-6, IL-8, MCP-1, MIP-1α, MIP-1β, RANTES, tumor necrosis factor α, IL-1RA, IL-10, SLPI). Gynol II was associated with more vaginal lesions. No endometrial disruptions were observed across conditions. In the vagina, RANTES (p=.055) and IL-6 (p=.04) were higher after HEC exposure than at baseline. In the endometrium, IL-1β (p=.003) and IL-8 (p=.025) were lower after Gynol II cycles than after no gel. Gynol II and HEC may modulate inflammatory markers in the vagina and endometrium. How these changes relate to infection susceptibility warrants further study. Copyright © 2011 Elsevier Inc. All rights reserved.

Multifeature Fusion Vehicle Detection Algorithm Based on Choquet Integral

Directory of Open Access Journals (Sweden)

Wenhui Li

2014-01-01

Full Text Available Vision-based multivehicle detection plays an important role in Forward Collision Warning Systems (FCWS and Blind Spot Detection Systems (BSDS. The performance of these systems depends on the real-time capability, accuracy, and robustness of vehicle detection methods. To improve the accuracy of vehicle detection algorithm, we propose a multifeature fusion vehicle detection algorithm based on Choquet integral. This algorithm divides the vehicle detection problem into two phases: feature similarity measure and multifeature fusion. In the feature similarity measure phase, we first propose a taillight-based vehicle detection method, and then vehicle taillight feature similarity measure is defined. Second, combining with the definition of Choquet integral, the vehicle symmetry similarity measure and the HOG + AdaBoost feature similarity measure are defined. Finally, these three features are fused together by Choquet integral. Being evaluated on public test collections and our own test images, the experimental results show that our method has achieved effective and robust multivehicle detection in complicated environments. Our method can not only improve the detection rate but also reduce the false alarm rate, which meets the engineering requirements of Advanced Driving Assistance Systems (ADAS.

A Vehicle Active Safety Model: Vehicle Speed Control Based on Driver Vigilance Detection Using Wearable EEG and Sparse Representation

Directory of Open Access Journals (Sweden)

Zutao Zhang

2016-02-01

Full Text Available In this paper, we present a vehicle active safety model for vehicle speed control based on driver vigilance detection using low-cost, comfortable, wearable electroencephalographic (EEG sensors and sparse representation. The proposed system consists of three main steps, namely wireless wearable EEG collection, driver vigilance detection, and vehicle speed control strategy. First of all, a homemade low-cost comfortable wearable brain-computer interface (BCI system with eight channels is designed for collecting the driver’s EEG signal. Second, wavelet de-noising and down-sample algorithms are utilized to enhance the quality of EEG data, and Fast Fourier Transformation (FFT is adopted to extract the EEG power spectrum density (PSD. In this step, sparse representation classification combined with k-singular value decomposition (KSVD is firstly introduced in PSD to estimate the driver’s vigilance level. Finally, a novel safety strategy of vehicle speed control, which controls the electronic throttle opening and automatic braking after driver fatigue detection using the above method, is presented to avoid serious collisions and traffic accidents. The simulation and practical testing results demonstrate the feasibility of the vehicle active safety model.

Vehicle model for tyre-ground contact force evaluation

OpenAIRE

Jiao, Lejia

2013-01-01

Economic development and growing integration process of world trade increases the demand for road transport. In 2008, the freight transportation by road in Sweden reached 42 million tonne-kilometers. Sweden has a tradition of long and heavy trucks combinations. Lots of larger vehicles, with a maximum length of 25.25 meters and weight of 60 tonnes, are used in national traffic. Heavier road transport and widely use of large vehicles contribute to the damages of pavement. According to a recent ...

Vehicle fault diagnostics and management system

Science.gov (United States)

Gopal, Jagadeesh; Gowthamsachin

2017-11-01

This project is a kind of advanced automatic identification technology, and is more and more widely used in the fields of transportation and logistics. It looks over the main functions with like Vehicle management, Vehicle Speed limit and Control. This system starts with authentication process to keep itself secure. Here we connect sensors to the STM32 board which in turn is connected to the car through Ethernet cable, as Ethernet in capable of sending large amounts of data at high speeds. This technology involved clearly shows how a careful combination of software and hardware can produce an extremely cost-effective solution to a problem.

A randomized, double-masked, parallel-group, comparative study to evaluate the clinical efficacy and safety of 1% azithromycin–0.1% dexamethasone combination compared to 1% azithromycin alone, dexamethasone 0.1% alone, and vehicle in the treatment of subjects with blepharitis

Directory of Open Access Journals (Sweden)

Hosseini K

2016-08-01

Full Text Available Kamran Hosseini,1 Richard L Lindstrom,2,3 Gary Foulks,4 Kelly K Nichols5 1InSite Vision, Alameda, CA, 2Minnesota Eye Consultants, 3Department of Ophthalmology and Visual Neurosciences, University of Minnesota Medical School, Minneapolis, MN, 4Department of Ophthalmology and Vision Science, School of Medicine, University of Louisville, Louisville, KY, 5School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA Purpose: To evaluate the clinical efficacy and safety of a 1% azithromycin–0.1% dexamethasone combination in DuraSite (“combination” compared to 0.1% dexamethasone in DuraSite, 1% azithromycin in DuraSite, and vehicle in the treatment of subjects with blepharitis.Materials and methods: This was a Phase III, double-masked, vehicle-controlled, four-arm study in which 907 subjects with blepharitis were randomized to combination (n=305, 0.1% dexamethasone (n=298, 1% azithromycin (n=155, or vehicle (n=149. Ten study visits were scheduled: screening visit, days 1 and 4 (dosing phase and 15, and months 1–6 (follow-up phase. On day 1, subjects applied one drop of the study drug to the eyelid of the inflamed eye(s twice daily, and continued with twice-daily dosing for 14 days. After completing 14 days of dosing, subjects were followed for 6 months for efficacy and safety.Results: A total of 57 subjects (6.3% had complete clinical resolution at day 15: 25 (8.2%, 17 (5.7%, 8 (5.2%, and 7 (4.7% subjects in the combination-, 0.1% dexamethasone-, 1% azithromycin-, and vehicle-treatment groups, respectively. The combination was superior to 1% azithromycin and vehicle alone, but not to 0.1% dexamethasone alone. Mean composite (total clinical sign and symptom scores improved in all four treatment groups during the posttreatment evaluation phase for the intent-to-treat population, but outcomes were superior when a drop containing 0.1% dexamethasone was utilized. Clinical response was noted as early as day 4, and persisted as long

A Framework for Analysing Driver Interactions with Semi-Autonomous Vehicles

Directory of Open Access Journals (Sweden)

Siraj Shaikh

2012-12-01

Full Text Available Semi-autonomous vehicles are increasingly serving critical functions in various settings from mining to logistics to defence. A key characteristic of such systems is the presence of the human (drivers in the control loop. To ensure safety, both the driver needs to be aware of the autonomous aspects of the vehicle and the automated features of the vehicle built to enable safer control. In this paper we propose a framework to combine empirical models describing human behaviour with the environment and system models. We then analyse, via model checking, interaction between the models for desired safety properties. The aim is to analyse the design for safe vehicle-driver interaction. We demonstrate the applicability of our approach using a case study involving semi-autonomous vehicles where the driver fatigue are factors critical to a safe journey.

Teleoperated Visual Inspection and Surveillance with Unmanned Ground and Aerial Vehicles

Directory of Open Access Journals (Sweden)

Viatcheslav Tretyakov

2008-11-01

Full Text Available This paper introduces our robotic system named UGAV (Unmanned Ground-Air Vehicle consisting of two semi-autonomous robot platforms, an Unmanned Ground Vehicle (UGV and an Unmanned Aerial Vehicles (UAV. The paper focuses on three topics of the inspection with the combined UGV and UAV: (A teleoperated control by means of cell or smart phones with a new concept of automatic configuration of the smart phone based on a RKI-XML description of the vehicles control capabilities, (B the camera and vision system with the focus to real time feature extraction e.g. for the tracking of the UAV and (C the architecture and hardware of the UAV

Vehicle state estimation using GPS/IMU integration

NARCIS (Netherlands)

Wang, Y.; Mangnus, J.; Kostić, D.; Nijmeijer, H.; Jansen, S.T.H.

2011-01-01

New driver support systems require knowledge of the vehicle position with great accuracy and reliability. Satellite navigation (GNSS) is generally insufficiently accurate for positioning and as an alternative to using a ground station, combinations with high quality motion sensors are used in

The future of hybrid vehicles

Energy Technology Data Exchange (ETDEWEB)

Vangraefschepe, F.; Menegazzi, P.

2004-12-15

This new demand from the U.S. market is being taken very seriously by key players in the field. GM and Daimler Chrysler have announced an alliance for the joint development of a hybrid vehicle scheduled to reach the market by 2007. Development projects of this type will require capital investment of several hundred million dollars over the period. Given that it is now imperative to cut greenhouse gas emissions, the hybrid vehicle offers a credible alternative. It is already on the market, despite the constraints inherent to a configuration combining an electric motor and an internal combustion engine, and despite the added cost. The technical choices are complex and varied, depending on the objectives: potential CO{sub 2} emissions gains range from a few percentage points to over 45%, depending on the engine/motor architecture. The gasoline hybrid vehicle is emerging as an alternative to the diesel engine, especially in Japan and the United States, but its growth will depend on the ability of the motor industry to reduce the added cost.

An optimal control-based algorithm for hybrid electric vehicle using preview route information

NARCIS (Netherlands)

Ngo, D.V.; Hofman, T.; Steinbuch, M.; Serrarens, A.F.A.

2010-01-01

Control strategies for Hybrid Electric Vehicles (HEVs) are generally aimed at optimally choosing the power distribution between the internal combustion engine and the electric motor in order to minimize the fuel consumption and/or emissions. Using vehicle navigation systems in combination with

Feasibility study on combined use of residential SOFC cogeneration system and plug-in hybrid electric vehicle from energy-saving viewpoint

International Nuclear Information System (INIS)

Wakui, Tetsuya; Wada, Naohiro; Yokoyama, Ryohei

2012-01-01

Highlights: ► Optimal operational planning for combined use of SOFC-CGS and PHEV is conducted. ► Charging PHEV with SOFC-CGS increases electric capacity factor of SOFC-CGS. ► Energy-saving effect of combined use is higher than that of their separate use. ► Combined use provides energy savings in both residential and transport sectors. - Abstract: The energy-saving effect of a combined use of a residential solid oxide fuel cell cogeneration system (SOFC-CGS) that adopts a continuous operation, and a plug-in hybrid electric vehicle (PHEV) is discussed by optimal operational planning based on mixed-integer linear programming. This combined use aims to increase the electric capacity factor of the SOFC-CGS by charging the PHEV using the SOFC-CGS electric power output late at night, and targets the application in regions where the reverse power flow from residential cogeneration systems to commercial electric power systems is not permitted, like in Japan. The optimal operation patterns of the combined use of 0.7-kWe SOFC-CGS and PHEV for a simulated energy demand with a sampling time of 1 h and various daily running distances of the PHEV show that this combined use increases the electric capacity factor of the SOFC-CGS and saves more energy in comparison with their separate use in which the SOFC-CGS is used but the PHEV is charged only with purchased electric power. Furthermore, it is found that at the PHEV daily running distance of 12 km/d, the reduction rate of the annual primary energy consumption for this combined use increases by up to 3.7 percentage points relative to their separate use. Consequently, this feasibility study reveals that the combined use of the SOFC-CGS and PHEV provides the synergistic effect on energy savings in the residential and transport sectors. For the practical use, simulation scenarios considering the energy demand fluctuations with short periods and real-time pricing of the purchased electric power must be considered as future

Electric vehicle station equipment for grid-integrated vehicles

Science.gov (United States)

Kempton, Willett; Kiamilev, Fouad; McGee, Rodney; Waite, Nick

2017-09-05

Methods, systems, and apparatus transferring power between the grid and an electric vehicle are disclosed. The apparatus may include at least one vehicle communication port for interfacing with electric vehicle equipment (EVE) and a processor coupled to the at least one vehicle communication port to establish communication with the EVE, receive EVE attributes from the EVE, and transmit electric vehicle station equipment (EVSE) attributes to the EVE. Power may be transferred between the grid and the electric vehicle by maintaining EVSE attributes, establishing communication with the EVE, and transmitting the EVSE maintained attributes to the EVE.

Ballistic Resistance of Armored Passenger Vehicles: Test Protocols and Quality Methods

Energy Technology Data Exchange (ETDEWEB)

Jeffrey M. Lacy; Robert E. Polk

2005-07-01

This guide establishes a test methodology for determining the overall ballistic resistance of the passenger compartment of assembled nontactical armored passenger vehicles (APVs). Because ballistic testing of every piece of every component of an armored vehicle is impractical, if not impossible, this guide describes a testing scheme based on statistical sampling of exposed component surface areas. Results from the test of the sampled points are combined to form a test score that reflects the probability of ballistic penetration into the passenger compartment of the vehicle.

Comparative costs and benefits of hydrogen vehicles

Energy Technology Data Exchange (ETDEWEB)

Berry, G.D. [Lawrence Livermore National Lab., CA (United States)

1996-10-01

The costs and benefits of hydrogen as a vehicle fuel are compared to gasoline, natural gas, and battery-powered vehicles. Costs, energy, efficiency, and tail-pipe and full fuel cycle emissions of air pollutants and greenhouse gases were estimated for hydrogen from a broad range of delivery pathways and scales: from individual vehicle refueling systems to large stations refueling 300 cars/day. Hydrogen production from natural gas, methanol, and ammonia, as well as water electrolysis based on alkaline or polymer electrolytes and steam electrolysis using solid oxide electrolytes are considered. These estimates were compared to estimates for competing fuels and vehicles, and used to construct oil use, air pollutant, and greenhouse gas emission scenarios for the U.S. passenger car fleet from 2005-2050. Fuel costs need not be an overriding concern in evaluating the suitability of hydrogen as a fuel for passenger vehicles. The combined emissions and oil import reduction benefits of hydrogen cars are estimated to be significant, valued at up to {approximately}$400/yr for each hydrogen car when primarily clean energy sources are used for hydrogen production. These benefits alone, however, become tenuous as the basis supporting a compelling rationale for hydrogen fueled vehicles, if efficient, advanced fossil-fuel hybrid electric vehicles (HEV`s) can achieve actual on-road emissions at or below ULEV standards in the 2005-2015 timeframe. It appears a robust rationale for hydrogen fuel and vehicles will need to also consider unique, strategic, and long-range benefits of hydrogen vehicles which can be achieved through the use of production, storage, delivery, and utilization methods for hydrogen which are unique among fuels: efficient use of intermittent renewable energy sources, (e,g, wind, solar), small-scale feasibility, fuel production at or near the point of use, electrolytic production, diverse storage technologies, and electrochemical conversion to electricity.

Optimal Contribution of Energy Management of Electric Vehicles

Directory of Open Access Journals (Sweden)

Insaf YAHIA

2016-12-01

Full Text Available An Electrical Vehicle (EV has the advantage of being friendly with environment but it does not have the same performance as a current conventional vehicle. This work proposes a strategy to improve the EV autonomy. At first, an EV model that combines lead acid batteries and a DC motor is described. The individual mathematical model for each component is developed in MATLAB. Moreover, the control speed strategy using fuzzy logic is applied to the system to produce a maximum speed reference of an EV under different states of charge of the battery and acceleration. Then, a proportional integral control adjusts the speed strategy. When the vehicle is subjected to different scenarios, the simulation realized in MATLAB/Simulink will show good efficiency.

Electric vehicle motors and controllers

Science.gov (United States)

Secunde, R. R.

1981-01-01

Improved and advanced components being developed include electronically commutated permanent magnet motors of both drum and disk configuration, an unconventional brush commutated motor, and ac induction motors and various controllers. Test results on developmental motors, controllers, and combinations thereof indicate that efficiencies of 90% and higher for individual components, and 80% to 90% for motor/controller combinations can be obtained at rated power. The simplicity of the developmental motors and the potential for ultimately low cost electronics indicate that one or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors.

Modeling and Validation of Power-split and P2 Parallel Hybrid Electric Vehicles SAE 2013-01-1470)

Science.gov (United States)

The Advanced Light-Duty Powertrain and Hybrid Analysis tool was created by EPA to evaluate the Greenhouse Gas (GHG) emissions of Light-Duty (LD) vehicles. It is a physics-based, forward-looking, full vehicle computer simulator capable of analyzing various vehicle types combined ...

Strategic vehicle fleet management - the replacement problem

Directory of Open Access Journals (Sweden)

Adam Redmer

2016-03-01

Full Text Available Background: Fleets constitute the most important production means in transportation. Their appropriate management is crucial for all companies having transportation duties. The paper is the third one of a series of three papers that the author dedicates to the strategic vehicle fleet management topic. Material and methods: The paper discusses ways of building replacement strategies for companies' fleets of vehicles. It means deciding for how long to exploit particular vehicles in a fleet (the fleet replacement problem - FR. The essence of this problem lies in the minimization of vehicle / fleet exploitation costs by balancing ownership and utilization costs and taking into account budget limitations. In the paper an original mathematical model (an optimization method allowing for the FR analysis is proposed. Results: An application of the proposed optimization method in a real-life decision situation (the case study within the Polish environment and the obtained solution are presented. The solution shows that there exist optimal exploitation periods of particular vehicles in a fleet. However, combination of them gives a replacement plan for an entire fleet violating budget constraints. But it is possible to adjust individual age to replacement of particular vehicles to fulfill budget constraints without losing economical optimality of a developed replacement plan for an entire fleet. Conclusions: The paper is the last one of a series of three papers that the author dedicated to the strategic vehicle fleet management topic including the following managerial decision problems: MAKE-or-BUY, sizing / composition and replacement.

The Cost-Optimal Size of Future Reusable Launch Vehicles

Science.gov (United States)

Koelle, D. E.

2000-07-01

The paper answers the question, what is the optimum vehicle size — in terms of LEO payload capability — for a future reusable launch vehicle ? It is shown that there exists an optimum vehicle size that results in minimum specific transportation cost. The optimum vehicle size depends on the total annual cargo mass (LEO equivalent) enviseaged, which defines at the same time the optimum number of launches per year (LpA). Based on the TRANSCOST-Model algorithms a wide range of vehicle sizes — from 20 to 100 Mg payload in LEO, as well as launch rates — from 2 to 100 per year — have been investigated. It is shown in a design chart how much the vehicle size as well as the launch rate are influencing the specific transportation cost (in MYr/Mg and USS/kg). The comparison with actual ELVs (Expendable Launch Vehicles) and Semi-Reusable Vehicles (a combination of a reusable first stage with an expendable second stage) shows that there exists only one economic solution for an essential reduction of space transportation cost: the Fully Reusable Vehicle Concept, with rocket propulsion and vertical take-off. The Single-stage Configuration (SSTO) has the best economic potential; its feasibility is not only a matter of technology level but also of the vehicle size as such. Increasing the vehicle size (launch mass) reduces the technology requirements because the law of scale provides a better mass fraction and payload fraction — practically at no cost. The optimum vehicle design (after specification of the payload capability) requires a trade-off between lightweight (and more expensive) technology vs. more conventional (and cheaper) technology. It is shown that the the use of more conventional technology and accepting a somewhat larger vehicle is the more cost-effective and less risky approach.

Development of a method to rate the primary safety of vehicles using linked New Zealand crash and vehicle licensing data.

Science.gov (United States)

Keall, Michael D; Newstead, Stuart

2016-01-01

Vehicle safety rating systems aim firstly to inform consumers about safe vehicle choices and, secondly, to encourage vehicle manufacturers to aspire to safer levels of vehicle performance. Primary rating systems (that measure the ability of a vehicle to assist the driver in avoiding crashes) have not been developed for a variety of reasons, mainly associated with the difficult task of disassociating driver behavior and vehicle exposure characteristics from the estimation of crash involvement risk specific to a given vehicle. The aim of the current study was to explore different approaches to primary safety estimation, identifying which approaches (if any) may be most valid and most practical, given typical data that may be available for producing ratings. Data analyzed consisted of crash data and motor vehicle registration data for the period 2003 to 2012: 21,643,864 observations (representing vehicle-years) and 135,578 crashed vehicles. Various logistic models were tested as a means to estimate primary safety: Conditional models (conditioning on the vehicle owner over all vehicles owned); full models not conditioned on the owner, with all available owner and vehicle data; reduced models with few variables; induced exposure models; and models that synthesised elements from the latter two models. It was found that excluding young drivers (aged 25 and under) from all primary safety estimates attenuated some high risks estimated for make/model combinations favored by young people. The conditional model had clear biases that made it unsuitable. Estimates from a reduced model based just on crash rates per year (but including an owner location variable) produced estimates that were generally similar to the full model, although there was more spread in the estimates. The best replication of the full model estimates was generated by a synthesis of the reduced model and an induced exposure model. This study compared approaches to estimating primary safety that could mimic

Transportable Emissions Testing Laboratory for Alternative Vehicles Emissions Testing

Energy Technology Data Exchange (ETDEWEB)

Clark, Nigel

2012-01-31

The overall objective of this project was to perform research to quantify and improve the energy efficiency and the exhaust emissions reduction from advanced technology vehicles using clean, renewable and alternative fuels. Advanced vehicle and alternative fuel fleets were to be identified, and selected vehicles characterized for emissions and efficiency. Target vehicles were to include transit buses, school buses, vocational trucks, delivery trucks, and tractor-trailers. Gaseous species measured were to include carbon monoxide, carbon dioxide, oxides of nitrogen, hydrocarbons, and particulate matter. An objective was to characterize particulate matter more deeply than by mass. Accurate characterization of efficiency and emissions was to be accomplished using a state-of-the-art portable emissions measurement system and an accompanying chassis dynamometer available at West Virginia University. These two units, combined, are termed the Transportable Laboratory. An objective was to load the vehicles in a real-world fashion, using coast down data to establish rolling resistance and wind drag, and to apply the coast down data to the dynamometer control. Test schedules created from actual vehicle operation were to be employed, and a specific objective of the research was to assess the effect of choosing a test schedule which the subject vehicle either cannot follow or can substantially outperform. In addition the vehicle loading objective was to be met better with an improved flywheel system.

Environmentally Responsible Aviation (ERA) Project - N+2 Advanced Vehicle Concepts Study and Conceptual Design of Subscale Test Vehicle (STV) Final Report

Science.gov (United States)

Bonet, John T.; Schellenger, Harvey G.; Rawdon, Blaine K.; Elmer, Kevin R.; Wakayama, Sean R.; Brown, Derrell L.; Guo, Yueping

2011-01-01

NASA has set demanding goals for technology developments to meet national needs to improve fuel efficiency concurrent with improving the environment to enable air transportation growth. A figure shows NASA's subsonic transport system metrics. The results of Boeing ERA N+2 Advanced Vehicle Concept Study show that the Blended Wing Body (BWB) vehicle, with ultra high bypass propulsion systems have the potential to meet the combined NASA ERA N+2 goals. This study had 3 main activities. 1) The development of an advanced vehicle concepts that can meet the NASA system level metrics. 2) Identification of key enabling technologies and the development of technology roadmaps and maturation plans. 3) The development of a subscale test vehicle that can demonstrate and mature the key enabling technologies needed to meet the NASA system level metrics. Technology maturation plans are presented and include key performance parameters and technical performance measures. The plans describe the risks that will be reduced with technology development and the expected progression of technical maturity.

Vehicle barriers: emphasis on natural features

International Nuclear Information System (INIS)

Adams, K.G.; Roscoe, B.J.

1985-07-01

The recent increase in the use of car and truck bombs by terrorist organizations has led NRC to evaluate the adequacy of licensee security against such threats. As part of this evaluation, one of the factors is the effectiveness of terrain and vegetation in providing barriers against the vehicle entry. The effectiveness of natural features is presented in two contexts. First, certain natural features are presented. Second, the effectiveness of combinations of features is presented. In addition to the discussion of natural features, this report provides a discussion of methods to slow vehicles. Also included is an overview of man-made barrier systems, with particular attention to ditches. 17 refs., 49 figs

High HIV prevalence and incidence among women in Southern Mozambique: Evidence from the MDP microbicide feasibility study.

Directory of Open Access Journals (Sweden)

Sibone Mocumbi

Full Text Available The study aimed to assess the feasibility of conducting large scale HIV prevention clinical trials in Mozambique by measuring HIV prevalence and incidence among women of reproductive age. This paper describes the baseline socio-demographic characteristics of the Mozambique Microbicides Development Programme (MDP feasibility cohort, baseline prevalence of HIV and other STIs, and HIV incidence.The Mozambique MDP feasibility study was conducted from September 2007 to August 2009 in urban Mavalane and rural Manhiça, in Southern Mozambique. Sexually active, HIV negative women aged 18 years and above were recruited to attend the study clinic every 4 weeks for a total of 40 weeks. At baseline, we collected demographic and sexual behaviour data, samples to test for sexually transmitted infections (STI and conducted HIV rapid testing. STI and HIV testing were repeated at clinical follow-up visits. We describe HIV prevalence of women at screening, the demographic, behavioural and clinical characteristics of women at enrolment, and HIV incidence during follow-up.We screened 793 women (369 at Mavalane and 424 at Manhiça and enrolled 505 eligible women (254 at Mavalane and 251 at Manhiça. Overall HIV prevalence at screening was 17%; 10% at Mavalane and 22% at Manhiça. Women screened at Manhiça were twice as likely as women screened at Mavalane to be HIV positive and HIV positive status was associated with younger age (18-34, lower educational level, not using a reliable method of contraception and being Zionist compared to other Christian religions. At enrolment contraceptive use was low in both clinics at 19% in Mavalane and 21% in Manhiça, as was reported condom use at last sex act at 48% in Mavalane and 25% in Manhiça. At enrolment, 8% of women tested positive for Trichomonas vaginalis, 2% for Neisseria gonorrhoeae, 4% for Chlamydia trachomatis and 46% for bacterial vaginosis. In Manhiça, 8% of women had active syphilis at screening. HIV incidence

Assessing the potential of different charging strategies for electric vehicle fleets in closed transport systems

International Nuclear Information System (INIS)

Schmidt, Johannes; Eisel, Matthias; Kolbe, Lutz M.

2014-01-01

A key reason for the low sales volumes of electric vehicles is their significantly higher purchasing price in comparison to conventional vehicles. However, various charging strategies can be applied to make these vehicles more profitable. In this paper, controlled charging concepts are transferred to commercial fleets operating in closed transport systems, as we found this field of application particularly well suited for the implementation of charging strategies. We analyzed data gathered in a field experiment conducted in a European port using electric vehicles in combination with a battery-swapping station to calculate the economic potentials of three charging scenarios: (1) optimizing energy procurement (2) trading load-shifting potential on control markets, and (3) a combination of the two. The findings indicate that all approaches are appropriate for reducing economic disadvantages of electric transport vehicles. Furthermore, we find that adjusting charging processes to avoid price peaks is more profitable than offering control reserve. Finally, focusing on the combination of both strategies seems to be most promising from an economic perspective. In this context, operational cost savings of more than 65% can be achieved compared to a similar dieselpowered vehicle when applying this strategy. - Highlights: • We model various charging strategies for electric transport vehicles. • The economic assessment is based on a field experiment with a port operator. • We consider the special market design of spot and ancillary service markets. • All charging strategies presented provide substantial cost-saving potentials. • Optimizing energy procurement is more profitable than offering control reserve

Pharmacokinetic assessment of dapivirine vaginal microbicide gel in healthy, HIV-negative women.

Science.gov (United States)

Nel, Annalene M; Coplan, Paul; Smythe, Shanique C; McCord, Karen; Mitchnick, Mark; Kaptur, Paulina E; Romano, Joseph

2010-11-01

To assess the pharmacokinetics of dapivirine in plasma and dapivirine concentrations in cervicovaginal fluids (CVF) and cervicovaginal tissues following vaginal administration of dapivirine microbicide gel in healthy, HIV-negative women for 10 days. A randomized, double-blind, phase I study was conducted at a single research center in South Africa. A total of 18 women used dapivirine gel (0.001%, 0.005%, or 0.02%) once daily on Days 1 and 10 and twice daily on Days 2-9. Pharmacokinetics of dapivirine were assessed in plasma on Days 1 and 10. Dapivirine concentrations were measured in CVF on Days 1 and 10 and in cervicovaginal tissues on Day 10. Safety was evaluated through laboratory tests (hematology, clinical chemistry, and urinalysis), physical examinations, and assessment of adverse events. Plasma concentrations of dapivirine increased over time with gel dose and were greater on Day 10 (C(max) 31 to 471 pg/ml) than Day 1 (C(max) 23 to 80 pg/ml). T(max) was 10-12 h on Day 1, and 9 h on Day 10. Concentrations in CVF generally increased with dose but were highly variable among participants. Mean peak values ranged from 4.6-8.3 × 10(6) pg/ml on Day 1 and from 2.3-20.7 × 10(6) pg/ml on Day 10 across dose groups. Dapivirine was detectable in all tissue biopsies on Day 10 at concentrations of 1.0-356 × 10(3) pg/mg. Dapivirine was widely distributed throughout the lower genital tract with low systemic absorption when administered in a vaginal gel formulation for 10 consecutive days. The gel was safe and well tolerated.

Hydrogen Fuel Cell Vehicles

OpenAIRE

Anton Francesch, Judit

1992-01-01

Hydrogen is an especially attractive transportation fuel. It is the least polluting fuel available, and can be produced anywhere there is water and a clean source of electricity. A fuel cycle in which hydrogen is produced by solar-electrolysis of water, or by gasification of renewably grown biomass, and then used in a fuel-cell powered electric-motor vehicle (FCEV), would produce little or no local, regional, or global pollution. Hydrogen FCEVs would combine the best features of bat...

Electric-Drive Vehicles

Energy Technology Data Exchange (ETDEWEB)

Septon, Kendall K [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-09-11

Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: Hybrid electric vehicles (HEVs), Plug-in hybrid electric vehicles (PHEVs), All-electric vehicles (EVs). Together, PHEVs and EVs can also be referred to as plug-in electric vehicles (PEVs).

Electric-Drive Vehicles

Energy Technology Data Exchange (ETDEWEB)

None

2017-09-01

Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: Hybrid electric vehicles (HEVs), Plug-in hybrid electric vehicles (PHEVs), All-electric vehicles (EVs). Together, PHEVs and EVs can also be referred to as plug-in electric vehicles (PEVs).

Environmental Evaluation of New Generation Vehicles and Vehicle Components

Energy Technology Data Exchange (ETDEWEB)

Schexnayder, S.M.

2002-02-06

This report documents assessments that address waste issues and life cycle impacts associated with the vehicle materials and vehicle technologies being developed under the Partnership for a New Generation of Vehicles (PNGV) program. We refer to these vehicles as 3XVs, referring to the PNGV goal that their fuel mileage be three times better than the baseline vehicle. To meet the program's fuel consumption goals, these vehicles substitute lightweight materials for heavier materials such as steel and iron that currently dominate the composition of vehicles, and use engineering and power system changes. Alternative power systems being developed through the PNGV program include batteries for hybrid electric vehicles and fuel cells. With respect to all these developments, it is imperative to learn what effects they will have on the environment before adopting these designs and technologies on a large-scale basis.

Utility emissions associated with electric and hybrid vehicle (EHV) charging

International Nuclear Information System (INIS)

1993-04-01

This project is a joint effort between the US Department of Energy (DOE) and the Electric Power Research Institute (EPRI) to conduct a comprehensive, in-depth assessment of the emission impacts of electric and hybrid vehicles (EHVs). The study determines local and regional emission impacts under a variety of scenarios, covering both conservative and optimistic assumptions about vehicle efficiency, power plant efficiency, and other factors. In all scenarios, EHV use significantly reduces urban emissions of CO, VOC, and TSP. Changes in NO x and CO 2 emissions are very sensitive to average or marginal power plant emissions and vehicle efficiency assumptions. NO x and CO 2 emissions changes vary dramatically by region. Certain combinations of EHV and CV scenarios and regions result in significant reductions, while other combinations result in significant increases. Careful use of these results is advised. In all scenarios, SO 2 increases with EHV use although the amount is small-less than 1% of total utility emissions even vath the deployment of 12 million EHVS. But because of emission cap provisions of the Clean Air Act Amendments of 1990, national SO 2 totals will not be allowed to increase. Thus, utilities will have to apply more stringent measures to combat increased SO 2 emissions due to the increased use of electric vehicles

The near-term hybrid vehicle program, phase 1

Science.gov (United States)

1979-01-01

Performance specifications were determined for a hybrid vehicle designed to achieve the greatest reduction in fuel consumption. Based on the results of systems level studies, a baseline vehicle was constructed with the following basic paramaters: a heat engine power peak of 53 kW (VW gasoline engine); a traction motor power peak of 30 kW (Siemens 1GV1, separately excited); a heat engine fraction of 0.64; a vehicle curb weight of 2080 kg; a lead acid battery (35 kg weight); and a battery weight fraction of 0.17. The heat engine and the traction motor are coupled together with their combined output driving a 3 speed automatic transmission with lockup torque converter. The heat engine is equipped withe a clutch which allows it to be decoupled from the system.

Potential for widespread electrification of personal vehicle travel in the United States

Science.gov (United States)

Needell, Zachary A.; McNerney, James; Chang, Michael T.; Trancik, Jessika E.

2016-09-01

Electric vehicles can contribute to climate change mitigation if coupled with decarbonized electricity, but only if vehicle range matches travellers’ needs. Evaluating electric vehicle range against a population’s needs is challenging because detailed driving behaviour must be taken into account. Here we develop a model to combine information from coarse-grained but expansive travel surveys with high-resolution GPS data to estimate the energy requirements of personal vehicle trips across the US. We find that the energy requirements of 87% of vehicle-days could be met by an existing, affordable electric vehicle. This percentage is markedly similar across diverse cities, even when per capita gasoline consumption differs significantly. We also find that for the highest-energy days, other vehicle technologies are likely to be needed even as batteries improve and charging infrastructure expands. Car sharing or other means to serve this small number of high-energy days could play an important role in the electrification and decarbonization of transportation.

Transformation of Althaea officinalis L. by Agrobacterium rhizogenes for the production of transgenic roots expressing the anti-HIV microbicide cyanovirin-N.

Science.gov (United States)

Drake, Pascal M W; de Moraes Madeira, Luisa; Szeto, Tim H; Ma, Julian K-C

2013-12-01

The marshmallow plant (Althaea officinalis L.) has been used for centuries in medicine and other applications. Valuable secondary metabolites have previously been identified in Agrobacterium rhizogenes-generated transgenic 'hairy' roots in this species. In the present study, transgenic roots were produced in A. officinalis using A. rhizogenes. In addition to wild-type lines, roots expressing the anti-human immunodeficiency virus microbicide candidate, cyanovirin-N (CV-N), were generated. Wild-type and CV-N root lines were transferred to liquid culture and increased in mass by 49 and 19 % respectively over a 7 day culture period. In the latter, the concentration of CV-N present in the root tissue was 2.4 μg/g fresh weight, with an average secretion rate into the growth medium of 0.02 μg/ml/24 h. A. officinalis transgenic roots may therefore in the future be used not only as a source of therapeutic secondary metabolites, but also as an expression system for the production of recombinant pharmaceuticals.

Batteries and fuel cells for emerging electric vehicle markets

Science.gov (United States)

Cano, Zachary P.; Banham, Dustin; Ye, Siyu; Hintennach, Andreas; Lu, Jun; Fowler, Michael; Chen, Zhongwei

2018-04-01

Today's electric vehicles are almost exclusively powered by lithium-ion batteries, but there is a long way to go before electric vehicles become dominant in the global automotive market. In addition to policy support, widespread deployment of electric vehicles requires high-performance and low-cost energy storage technologies, including not only batteries but also alternative electrochemical devices. Here, we provide a comprehensive evaluation of various batteries and hydrogen fuel cells that have the greatest potential to succeed in commercial applications. Three sectors that are not well served by current lithium-ion-powered electric vehicles, namely the long-range, low-cost and high-utilization transportation markets, are discussed. The technological properties that must be improved to fully enable these electric vehicle markets include specific energy, cost, safety and power grid compatibility. Six energy storage and conversion technologies that possess varying combinations of these improved characteristics are compared and separately evaluated for each market. The remainder of the Review briefly discusses the technological status of these clean energy technologies, emphasizing barriers that must be overcome.

Vertical Takeoff and Landing Vehicle with Increased Cruise Efficiency

Science.gov (United States)

Fredericks, William J. (Inventor); Moore, Mark D. (Inventor); Busan, Ronald C. (Inventor); Rothhaar, Paul M. (Inventor); North, David D. (Inventor); Langford, William M. (Inventor); Laws, Christopher T. (Inventor); Hodges, William T. (Inventor); Johns, Zachary R. (Inventor); Webb, Sandy R. (Inventor)

2018-01-01

Systems, methods, and devices are provided that combine an advance vehicle configuration, such as an advanced aircraft configuration, with the infusion of electric propulsion, thereby enabling a four times increase in range and endurance while maintaining a full vertical takeoff and landing ("VTOL") and hover capability for the vehicle. Embodiments may provide vehicles with both VTOL and cruise efficient capabilities without the use of ground infrastructure. An embodiment vehicle may comprise a wing configured to tilt through a range of motion, a first series of electric motors coupled to the wing and each configured to drive an associated wing propeller, a tail configured to tilt through the range of motion, a second series of electric motors coupled to the tail and each configured to drive an associated tail propeller, and an electric propulsion system connected to the first series of electric motors and the second series of electric motors.

Crewed Space Vehicle Battery Safety Requirements

Science.gov (United States)

Jeevarajan, Judith A.; Darcy, Eric C.

2014-01-01

This requirements document is applicable to all batteries on crewed spacecraft, including vehicle, payload, and crew equipment batteries. It defines the specific provisions required to design a battery that is safe for ground personnel and crew members to handle and/or operate during all applicable phases of crewed missions, safe for use in the enclosed environment of a crewed space vehicle, and safe for use in launch vehicles, as well as in unpressurized spaces adjacent to the habitable portion of a space vehicle. The required provisions encompass hazard controls, design evaluation, and verification. The extent of the hazard controls and verification required depends on the applicability and credibility of the hazard to the specific battery design and applicable missions under review. Evaluation of the design and verification program results shall be completed prior to certification for flight and ground operations. This requirements document is geared toward the designers of battery systems to be used in crewed vehicles, crew equipment, crew suits, or batteries to be used in crewed vehicle systems and payloads (or experiments). This requirements document also applies to ground handling and testing of flight batteries. Specific design and verification requirements for a battery are dependent upon the battery chemistry, capacity, complexity, charging, environment, and application. The variety of battery chemistries available, combined with the variety of battery-powered applications, results in each battery application having specific, unique requirements pertinent to the specific battery application. However, there are basic requirements for all battery designs and applications, which are listed in section 4. Section 5 includes a description of hazards and controls and also includes requirements.

Description of light-vehicle pre-crash scenarios for safety applications based on vehicle-to-vehicle communications

Science.gov (United States)

2013-05-31

This report describes pre-crash scenarios that might be addressed by vehicle-to-vehicle communications. The focus is on crashes involving at least 1 light vehicle with a gross vehicle weight rating of 10,000 pounds or less. The 2004-2008 General Esti...

Aero-Assisted Pre-Stage for Ballistic and Aero-Assisted Launch Vehicles

Science.gov (United States)

Ustinov, Eugene A.

2012-01-01

A concept of an aero-assisted pre-stage is proposed, which enables launch of both ballistic and aero-assisted launch vehicles from conventional runways. The pre-stage can be implemented as a delta-wing with a suitable undercarriage, which is mated with the launch vehicle, so that their flight directions are coaligned. The ample wing area of the pre-stage combined with the thrust of the launch vehicle ensure prompt roll-out and take-off of the stack at airspeeds typical for a conventional jet airliner. The launch vehicle is separated from the pre-stage as soon as safe altitude is achieved, and the desired ascent trajectory is reached. Nominally, the pre-stage is non-powered. As an option, to save the propellant of the launch vehicle, the pre-stage may have its own short-burn propulsion system, whereas the propulsion system of the launch vehicle is activated at the separation point. A general non-dimensional analysis of performance of the pre-stage from roll-out to separation is carried out and applications to existing ballistic launch vehicle and hypothetical aero-assisted vehicles (spaceplanes) are considered.

Modular Estimation Strategy of Vehicle Dynamic Parameters for Motion Control Applications

Directory of Open Access Journals (Sweden)

Rawash Mustafa

2018-01-01

Full Text Available The presence of motion control or active safety systems in vehicles have become increasingly important for improving vehicle performance and handling and negotiating dangerous driving situations. The performance of such systems would be improved if combined with knowledge of vehicle dynamic parameters. Since some of these parameters are difficult to measure, due to technical or economic reasons, estimation of those parameters might be the only practical alternative. In this paper, an estimation strategy of important vehicle dynamic parameters, pertaining to motion control applications, is presented. The estimation strategy is of a modular structure such that each module is concerned with estimating a single vehicle parameter. Parameters estimated include: longitudinal, lateral, and vertical tire forces – longitudinal velocity – vehicle mass. The advantage of this strategy is its independence of tire parameters or wear, road surface condition, and vehicle mass variation. Also, because of its modular structure, each module could be later updated or exchanged for a more effective one. Results from simulations on a 14-DOF vehicle model are provided here to validate the strategy and show its robustness and accuracy.

Real-time vehicle detection and tracking in video based on faster R-CNN

Science.gov (United States)

Zhang, Yongjie; Wang, Jian; Yang, Xin

2017-08-01

Vehicle detection and tracking is a significant part in auxiliary vehicle driving system. Using the traditional detection method based on image information has encountered enormous difficulties, especially in complex background. To solve this problem, a detection method based on deep learning, Faster R-CNN, which has very high detection accuracy and flexibility, is introduced. An algorithm of target tracking with the combination of Camshift and Kalman filter is proposed for vehicle tracking. The computation time of Faster R-CNN cannot achieve realtime detection. We use multi-thread technique to detect and track vehicle by parallel computation for real-time application.

Vehicles with fuel cells: dream or reality

Energy Technology Data Exchange (ETDEWEB)

van den Broeck, H; Hovestreydt, G

1979-01-01

Elenco N.V. is developing a hydrogen/potassium hydroxide/air fuel cell system of 10-50 kw with a specific performance of 72 mw/sq cm and a practical operating life of 5000 hr, which will be available in 1981-82. A comparative cost study was performed for vehicles with 100% fuel cells, 100% batteries, hybrid systems of fuel cells combined with batteries that provide high power for acceleration, hydrogen combustion engines, and conventional diesel engines, for city bus fleets, light commercial vehicles, forklifts, and trucks in Holland and Belgium. Hybrid systems give the best economy and they should become competitive with diesel engines after 1990.

Electric vehicles

Science.gov (United States)

1990-03-01

Quiet, clean, and efficient, electric vehicles (EVs) may someday become a practical mode of transportation for the general public. Electric vehicles can provide many advantages for the nation's environment and energy supply because they run on electricity, which can be produced from many sources of energy such as coal, natural gas, uranium, and hydropower. These vehicles offer fuel versatility to the transportation sector, which depends almost solely on oil for its energy needs. Electric vehicles are any mode of transportation operated by a motor that receives electricity from a battery or fuel cell. EVs come in all shapes and sizes and may be used for different tasks. Some EVs are small and simple, such as golf carts and electric wheel chairs. Others are larger and more complex, such as automobile and vans. Some EVs, such as fork lifts, are used in industries. In this fact sheet, we will discuss mostly automobiles and vans. There are also variations on electric vehicles, such as hybrid vehicles and solar-powered vehicles. Hybrid vehicles use electricity as their primary source of energy, however, they also use a backup source of energy, such as gasoline, methanol or ethanol. Solar-powered vehicles are electric vehicles that use photovoltaic cells (cells that convert solar energy to electricity) rather than utility-supplied electricity to recharge the batteries. These concepts are discussed.

Anti-HIV-1 activity of anionic polymers: a comparative study of candidate microbicides

Directory of Open Access Journals (Sweden)

Li Yun-Yao

2002-11-01

Full Text Available Abstract Background Cellulose acetate phthalate (CAP in soluble form blocks coreceptor binding sites on the virus envelope glycoprotein gp120 and elicits gp41 six-helix bundle formation, processes involved in virus inactivation. CAP is not soluble at pH Methods Enzyme linked immunosorbent assays (ELISA were used to (1 study HIV-1 IIIB and BaL binding to micronized CAP; (2 detect virus disintegration; and (3 measure gp41 six-helix bundle formation. Cells containing integrated HIV-1 LTR linked to the β-gal gene and expressing CD4 and coreceptors CXCR4 or CCR5 were used to measure virus infectivity. Results 1 HIV-1 IIIB and BaL, respectively, effectively bound to micronized CAP. 2 The interaction between HIV-1 and micronized CAP led to: (a gp41 six-helix bundle formation; (b virus disintegration and shedding of envelope glycoproteins; and (c rapid loss of infectivity. Polymers other than CAP, except Carbomer 974P, elicited gp41 six-helix bundle formation in HIV-1 IIIB but only poly(napthalene sulfonate, in addition to CAP, had this effect on HIV-1 BaL. These polymers differed with respect to their virucidal activities, the differences being more pronounced for HIV-1 BaL. Conclusions Micronized CAP is the only candidate topical microbicide with the capacity to remove rapidly by adsorption from physiological fluids HIV-1 of both the X4 and R5 biotypes and is likely to prevent virus contact with target cells. The interaction between micronized CAP and HIV-1 leads to rapid virus inactivation. Among other anionic polymers, cellulose sulfate, BufferGel and aryl sulfonates appear most effective in this respect.

Inspection vehicle

International Nuclear Information System (INIS)

Takahashi, Masaki; Omote, Tatsuyuki; Yoneya, Yutaka; Tanaka, Keiji; Waki, Tetsuro; Yoshida, Tomiji; Kido, Tsuyoshi.

1993-01-01

An inspection vehicle comprises a small-sized battery directly connected with a power motor or a direct power source from trolly lines and a switching circuit operated by external signals. The switch judges advance or retreat by two kinds of signals and the inspection vehicle is recovered by self-running. In order to recover the abnormally stopped inspection vehicle to the targeted place, the inspection vehicle is made in a free-running state by using a clutch mechanism and is pushed by an other vehicle. (T.M.)

Fire Detection Tradeoffs as a Function of Vehicle Parameters

Science.gov (United States)

Urban, David L.; Dietrich, Daniel L.; Brooker, John E.; Meyer, Marit E.; Ruff, Gary A.

2016-01-01

Fire survivability depends on the detection of and response to a fire before it has produced an unacceptable environment in the vehicle. This detection time is the result of interplay between the fire burning and growth rates; the vehicle size; the detection system design; the transport time to the detector (controlled by the level of mixing in the vehicle); and the rate at which the life support system filters the atmosphere, potentially removing the detected species or particles. Given the large differences in critical vehicle parameters (volume, mixing rate and filtration rate) the detection approach that works for a large vehicle (e.g. the ISS) may not be the best choice for a smaller crew capsule. This paper examines the impact of vehicle size and environmental control and life support system parameters on the detectability of fires in comparison to the hazard they present. A lumped element model was developed that considers smoke, heat, and toxic product release rates in comparison to mixing and filtration rates in the vehicle. Recent work has quantified the production rate of smoke and several hazardous species from overheated spacecraft polymers. These results are used as the input data set in the lumped element model in combination with the transport behavior of major toxic products released by overheating spacecraft materials to evaluate the necessary alarm thresholds to enable appropriate response to the fire hazard.

Traffic State Estimation Using Connected Vehicles and Stationary Detectors

Directory of Open Access Journals (Sweden)

Ellen F. Grumert

2018-01-01

Full Text Available Real-time traffic state estimation is of importance for efficient traffic management. This is especially the case for traffic management systems that require fast detection of changes in the traffic conditions in order to apply an effective control measure. In this paper, we propose a method for estimating the traffic state and speed and density, by using connected vehicles combined with stationary detectors. The aim is to allow fast and accurate estimation of changes in the traffic conditions. The proposed method does only require information about the speed and the position of connected vehicles and can make use of sparsely located stationary detectors to limit the dependence on the infrastructure equipment. An evaluation of the proposed method is carried out by microscopic traffic simulation. The traffic state estimated using the proposed method is compared to the true simulated traffic state. Further, the density estimates are compared to density estimates from one detector-based method, one combined method, and one connected-vehicle-based method. The results of the study show that the proposed method is a promising alternative for estimating the traffic state in traffic management applications.

A comparative evaluation of energy storage systems for a fuel cell vehicle. Paper no. IGEC-1-142

International Nuclear Information System (INIS)

Marshall, J.; Kazerani, M.

2005-01-01

The widespread operation of internal combustion engine (ICE) vehicles has today become a great cause for concern due to the uncertainty of fossil fuel reserves, energy security issues, and numerous adverse environmental effects. Alternatives such as fuel cell vehicles, electric vehicles, hybrid vehicles, and biodiesel vehicles provide the possibility to ease some or all of these concerns. The fuel cell vehicle, however, offers an excellent combination of reducing ICE vehicle problems while maintaining the performance, driving range, and convenience that consumers require. This paper documents a comparative evaluation of an extremely important facet of the fuel cell vehicle: the energy storage system (ESS). Batteries and ultracapacitors, the two most common choices for an ESS, are compared qualitatively to illustrate the advantages and disadvantages of each. Also, a quantitative comparison is made to choose the best technology for a small fuel cell-powered SUV having the design objectives of high performance and high efficiency. Practical issues such as availability and cost are also considered. The results of the analysis indicate that a battery ESS provides the best combination of efficiency, performance, and cost for a present-day fuel cell vehicle design. Yet, if the anticipated cost reductions and improvements in the energy storage capabilities of ultracapacitors do occur, ultracapacitors will become a very strong contender for energy storage solutions of future fuel cell vehicles. (author)

Vehicle detection based on the use of shadow region and edge

Science.gov (United States)

Jeong, Sangheon; Kang, Seongkoo; Kim, Joongkyu

2013-07-01

Automotive and advanced driver assistance systems have attracted a great deal of attention lately. In these systems, effective and reliable vehicle detection is important because such systems can reduce the number of accidents and save human' lives. This paper describes an approach to detecting a forward vehicle using a camera mounted on the moving vehicle. In this paper, we describe two methods to detect a vehicle on the road. First, by using the vehicle's shadow, we can obtain the general location of the vehicular candidate. Second, we can identify the strong vertical edges at the left and right position of a vehicle. By combining the shadows and the edge, we can detect the vehicle's location. But other regions may also be detected, such as car windows, reflections, and illumination by the sun. In order to remove these other factors, defined as noises, we need to use a filter. After using the filter, we can calculate the exact location of the vehicle. Additionally, by using connected component labeling, we can obtain coordinates and establish the vehicle's location. Connected component labeling find all connected components in an image and assigns a unique label to all points in the same component. These methods are very useful for vehicle detection and the development of the driving assistance systems, and they can protect drivers' safety from having an accident.

Traffic Information Unit, Traffic Information System, Vehicle Management System, Vehicle, and Method of Controlling a Vehicle

NARCIS (Netherlands)

Papp, Z.; Doodeman, G.J.N.; Nelisse, M.W.; Sijs, J.; Theeuwes, J.A.C.; Driessen, B.J.F.

2010-01-01

A traffic information unit (MD1, MD2, MD3) according to the invention comprises a facility (MI) for tracking vehicle state information of individual vehicles present at a traffic infrastructure and a facility (T) for transmitting said vehicle state information to a vehicle (70B, 70E). A traffic

Differential in vitro inhibitory activity against HIV-1 of alpha-(1-3- and alpha-(1-6-D-mannose specific plant lectins : Implication for microbicide development

Directory of Open Access Journals (Sweden)

Balzarini Jan

2007-06-01

Full Text Available Abstract Background Plant lectins such as Galanthus nivalis agglutinin (GNA and Hippeastrum hybrid agglutinin (HHA are natural proteins able to link mannose residues, and therefore inhibit HIV-target cell interactions. Plant lectins are candidate for microbicide development. Objective To evaluate the activity against HIV of the mannose-specific plant lectins HHA and GNA at the cellular membrane level of epithelial cells and monocyte-derived dendritic cells (MDDC, two potential target cells of HIV at the genital mucosal level. Methods The inhibitory effects of HHA and GNA were evaluated on HIV adsorption to genital epithelial HEC-1A cell line, on HIV transcytosis throughout a monolayer of polarized epithelial HEC-1A cells, on HIV adsorption to MDDC and on transfer of HIV from MDDC to autologous T lymphocytes. Results HHA faintly inhibited attachment to HEC-1A cells of the R5-tropic HIV-1Ba-L strain, in a dose-dependent manner, whereas GNA moderately inhibited HIV adsorption in the same context, but only at high drug doses. Only HHA, but not GNA, inhibited HIV-1JR-CSF transcytosis in a dose-dependent manner. By confocal microscopy, HHA, but not GNA, was adsorbed at the epithelial cell surface, suggesting that HHA interacts specifically with receptors mediating HIV-1 transcytosis. Both plant lectins partially inhibited HIV attachment to MDDC. HHA inhibited more efficiently the transfer of HIV from MDDC to T cell, than GNA. Both HHA and GNA lacked toxicity below 200 μg/ml irrespective the cellular system used and do not disturb the monolayer integrity of epithelial cells. Conclusion These observations demonstrate higher inhibitory activities of the lectin plant HHA by comparison to GNA, on HIV adsorption to HEC-1A cell line, HIV transcytosis through HEC-1A cell line monolayer, HIV adsorption to MDDC and HIV transfer from MDDC to T cells, highlighting the potential interest of HHA as effective microbicide against HIV.

Commercial lubricant use among HIV-negative men who have sex with men in Los Angeles: implications for the development of rectal microbicides for HIV prevention.

Science.gov (United States)

Pines, Heather A; Gorbach, Pamina M; Reback, Cathy J; Landovitz, Raphael J; Mutchler, Matt G; Mitsuyasu, Ronald

2014-01-01

To inform the development and assess potential use of rectal microbicide gels for HIV prevention among men who have sex with men (MSM), we examined the dynamics and contexts of commercial lubricant use during receptive anal intercourse (RAI) within this population. From 2007 to 2010, 168 HIV-negative MSM living in Los Angeles who practice RAI completed computer-assisted self-interviews, which collected information on their last sexual event with ≤3 recent partners, at baseline, three months, and one-year study visits. Logistic generalized linear mixed models were used to identify individual- and sexual event-level characteristics associated with commercial lubricant use during RAI at the last sexual event within 421 partnerships reported by participants over the course of follow-up. During RAI at their last sexual event, 57% of partnerships used a condom and 69% used commercial lubricant. Among partnerships that used commercial lubricant, 56% reported lubricant application by both members of the partnership, 66% first applied lubricant during sex, but before penetration, and 98% applied lubricant at multiple locations. The relationship between substance use and commercial lubricant use varied by condom use (interaction p-value = 0.01). Substance use was positively associated with commercial lubricant use within partnerships that did not use condoms during RAI at their last sexual event (AOR = 4.47, 95% [corrected] [CI]: 1.63-12.28), but no association was observed within partnerships that did use condoms (AOR = 0.66, 95% CI: 0.23-1.85). Commercial lubricant use during RAI was also positively associated with reporting more sexual partners (AOR = 1.18, 95% CI: 1.05-1.31), while older age (units = 5 years; AOR = 0.75, 95% CI: 0.61-0.94), homelessness (past year; AOR = 0.32, 95% CI: 0.13-0.76), and having sex with an older (>10 years) partner (AOR = 0.37, 95% CI: 0.14-0.95) were negatively associated with commercial lubricant use. These factors should be considered

Terminal Sliding Mode Tracking Controller Design for Automatic Guided Vehicle

Science.gov (United States)

Chen, Hongbin

2018-03-01

Based on sliding mode variable structure control theory, the path tracking problem of automatic guided vehicle is studied, proposed a controller design method based on the terminal sliding mode. First of all, through analyzing the characteristics of the automatic guided vehicle movement, the kinematics model is presented. Then to improve the traditional expression of terminal sliding mode, design a nonlinear sliding mode which the convergence speed is faster than the former, verified by theoretical analysis, the design of sliding mode is steady and fast convergence in the limited time. Finally combining Lyapunov method to design the tracking control law of automatic guided vehicle, the controller can make the automatic guided vehicle track the desired trajectory in the global sense as well as in finite time. The simulation results verify the correctness and effectiveness of the control law.

Vehicle Tracking System, Vehicle Infrastructure Provided with Vehicle Tracking System and Method for Tracking

NARCIS (Netherlands)

Papp, Z.; Doodeman, G.J.N.; Nelisse, M.W.; Sijs, J.; Theeuwes, J.A.C.; Driessen, B.J.F.

2010-01-01

A vehicle tracking system is described comprising - a plurality of sensor nodes (10) that each provide a message (D) indicative for an occupancy status of a detection area of an vehicle infrastructure monitored by said sensor node, said sensor nodes (10) being arranged in the vehicle infrastructure

Control strategy of hydraulic/electric synergy system in heavy hybrid vehicles

Energy Technology Data Exchange (ETDEWEB)

Sun Hui; Yang Lifu; Junqing Jing; Yanling Luo [Jiangsu Xuzhou Construction Machinery Research Institute, Jiangsu (China)

2011-01-15

Energy consumption and exhaust emissions of hybrid vehicles strongly depend on the energy storage source and the applied control strategy. Heavy vehicles have the characteristics of frequent starts/stops and significant amounts of braking energy, which needs to find a more efficient way to store and use the high power flow. A novel parallel hybrid vehicles configuration consisting of hydraulic/electric synergy system is proposed to overcome the existing drawbacks of single energy storage source in heavy hybrid vehicles. A control strategy combining a logic threshold approach and key parameters optimization algorithm is developed to achieve acceptable vehicle performance while simultaneously maximizing engine fuel economy and maintaining the battery state of charge in its rational operation range at all times. The experimental and simulation results illustrate the potential of the proposed control strategy in terms of fuel economy and in keeping the deviations of SOC at high efficiency range. (author)

Control strategy of hydraulic/electric synergy system in heavy hybrid vehicles

International Nuclear Information System (INIS)

Sun Hui; Yang Lifu; Jing Junqing; Luo Yanling

2011-01-01

Energy consumption and exhaust emissions of hybrid vehicles strongly depend on the energy storage source and the applied control strategy. Heavy vehicles have the characteristics of frequent starts/stops and significant amounts of braking energy, which needs to find a more efficient way to store and use the high power flow. A novel parallel hybrid vehicles configuration consisting of hydraulic/electric synergy system is proposed to overcome the existing drawbacks of single energy storage source in heavy hybrid vehicles. A control strategy combining a logic threshold approach and key parameters optimization algorithm is developed to achieve acceptable vehicle performance while simultaneously maximizing engine fuel economy and maintaining the battery state of charge in its rational operation range at all times. The experimental and simulation results illustrate the potential of the proposed control strategy in terms of fuel economy and in keeping the deviations of SOC at high efficiency range.

Discrete Optimization Model for Vehicle Routing Problem with Scheduling Side Cosntraints

Science.gov (United States)

Juliandri, Dedy; Mawengkang, Herman; Bu'ulolo, F.

2018-01-01

Vehicle Routing Problem (VRP) is an important element of many logistic systems which involve routing and scheduling of vehicles from a depot to a set of customers node. This is a hard combinatorial optimization problem with the objective to find an optimal set of routes used by a fleet of vehicles to serve the demands a set of customers It is required that these vehicles return to the depot after serving customers’ demand. The problem incorporates time windows, fleet and driver scheduling, pick-up and delivery in the planning horizon. The goal is to determine the scheduling of fleet and driver and routing policies of the vehicles. The objective is to minimize the overall costs of all routes over the planning horizon. We model the problem as a linear mixed integer program. We develop a combination of heuristics and exact method for solving the model.

Fuels demand by light vehicles and motorcycles In Brazil

Energy Technology Data Exchange (ETDEWEB)

Gomez, Jose Manoel Antelo [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

2010-07-01

The purpose of this paper is to analyze the consumption of gasoline, alcohol and natural gas vehicle (NGV) by light vehicles and motorcycles in Brazil. Through the estimation of fleets per consumption class, in an environment influenced by a new engine technology (flex-fuel), this exercise estimates the fleet-elasticity of cars (and motorcycles) powered by gasoline, hydrated alcohol, natural gas vehicle (NGV) and flex-fuel, in addition to the income elasticity within the period from January, 2000 to December, 2008. This paper uses an alternative variable as income proxy and estimates the five different fleets through the combination of vehicles sales and scrapping curves. This paper's conclusion is that given specific issues of the Brazilian fuel market, in special prices and technological innovations, the fleets' equations for the consumption of the three fuels represent in a more significant manner the relationships expected between supply and demand variables than the commonly used functions of prices and income. (author)

Fuels demand by light vehicles and motorcycles In Brazil

Energy Technology Data Exchange (ETDEWEB)

Gomez, Jose Manoel Antelo [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

2010-07-01

The purpose of this paper is to analyze the consumption of gasoline, alcohol and natural gas vehicle (NGV) by light vehicles and motorcycles in Brazil. Through the estimation of fleets per consumption class, in an environment influenced by a new engine technology (flex-fuel), this exercise estimates the fleet-elasticity of cars (and motorcycles) powered by gasoline, hydrated alcohol, natural gas vehicle (NGV) and flex-fuel, in addition to the income elasticity within the period from January, 2000 to December, 2008. This paper uses an alternative variable as income proxy and estimates the five different fleets through the combination of vehicles sales and scrapping curves. This paper's conclusion is that given specific issues of the Brazilian fuel market, in special prices and technological innovations, the fleets' equations for the consumption of the three fuels represent in a more significant manner the relationships expected between supply and demand variables than the commonly used functions of prices and income. (author)

3 tons pure electric vehicles power system design based on Cruise

Directory of Open Access Journals (Sweden)

Xinyu Liu

2017-01-01

Full Text Available The pure electric minivan is different from electric car. Combined with a given vehicle, vehicle simulation model established in Cruise software, complete simulation by setting tasks for the selected models designed drivetrain. Simulation results show that: The design of the transmission ratio can best meet the performance requirements of the matching target power analysis and simulation of electric minivan provides a new way, with practical guidance.

Heavy-Duty Vehicle Port Drayage Drive Cycle Characterization and Development

Energy Technology Data Exchange (ETDEWEB)

Prohaska, Robert; Konan, Arnaud; Kelly, Kenneth; Lammert, Michael

2016-10-06

In an effort to better understand the operational requirements of port drayage vehicles and their potential for adoption of advanced technologies, National Renewable Energy Laboratory (NREL) researchers collected over 36,000 miles of in-use duty cycle data from 30 Class 8 drayage trucks operating at the Port of Long Beach and Port of Los Angeles in Southern California. These data include 1-Hz global positioning system location and SAE J1939 high-speed controller area network information. Researchers processed the data through NREL's Drive-Cycle Rapid Investigation, Visualization, and Evaluation tool to examine vehicle kinematic and dynamic patterns across the spectrum of operations. Using the k-medoids clustering method, a repeatable and quantitative process for multi-mode drive cycle segmentation, the analysis led to the creation of multiple drive cycles representing four distinct modes of operation that can be used independently or in combination. These drive cycles are statistically representative of real-world operation of port drayage vehicles. When combined with modeling and simulation tools, these representative test cycles allow advanced vehicle or systems developers to efficiently and accurately evaluate vehicle technology performance requirements to reduce cost and development time while ultimately leading to the commercialization of advanced technologies that meet the performance requirements of the port drayage vocation. The drive cycles, which are suitable for chassis dynamometer testing, were compared to several existing test cycles. This paper presents the clustering methodology, accompanying results of the port drayage duty cycle analysis and custom drive cycle creation.

Vibrational Comfort on Board the Vehicle: Influence of Speed Bumps and Comparison between Different Categories of Vehicle

Directory of Open Access Journals (Sweden)

Vincenzo Barone

2016-01-01

Full Text Available This paper shows the results of a study conducted on five different categories of vehicles in a specific test site. The aim was to investigate how the effect of the test site discontinuity determines variations of comfort related to the increase in speed and to the five selected road vehicles of different classes. Measurements were obtained by combining data relating to vibrations in the three reference axes, detected through a vibration dosimeter (VIB-008, and geolocation data (latitude, longitude, and speed identified by the GPS inside a smartphone. This procedure, through the synchronization between dosimeter and GPS location, has been helpful in postprocessing to eliminate any measurement anomalies generated by the operator. After the survey campaign it was determined that a formulation allows defining a Comfort Index (CI depending on velocity and five vehicles of different classes. This study showed that the presence of speed bumps, in the test site investigated, appears to be uncomfortable even at speeds well below those required by the Highway Code.

Stabilization of car-caravan combination using independent steer and drive/or brake forces distribution

Directory of Open Access Journals (Sweden)

Ossama Mokhiamar

2015-09-01

Full Text Available Once a combined vehicle becomes unstable, it is very difficult for a driver to stabilize it especially under severe driving conditions, such as turning with braking. This is mainly due to the effect of the towed vehicle on the towing vehicle through the hitch jackknifing. This effect makes the handling characteristics of a car-caravan combination different from those of a single vehicle. Therefore, this paper proposes a control design concept for an optimum distribution of longitudinal and lateral forces of the four tires of a towing vehicle. The mean objectives of the control system were to stabilize the motion of an articulated vehicle utilizing the tires entire ability in both longitudinal and lateral directions as well as to make the handling characteristics of an articulated vehicle similar to those of a single one. The sliding control law based on vehicle planar equations of motion is used to derive the control laws. The proposed control system is evaluated under severe driving conditions and compared with the results of integrated control systems. The robustness of the articulated vehicle motion with the proposed control against the coefficient of friction variation is discussed.

How important is vehicle safety in the new vehicle purchase process?

Science.gov (United States)

Koppel, Sjaanie; Charlton, Judith; Fildes, Brian; Fitzharris, Michael

2008-05-01

Whilst there has been a significant increase in the amount of consumer interest in the safety performance of privately owned vehicles, the role that it plays in consumers' purchase decisions is poorly understood. The aims of the current study were to determine: how important vehicle safety is in the new vehicle purchase process; what importance consumers place on safety options/features relative to other convenience and comfort features, and how consumers conceptualise vehicle safety. In addition, the study aimed to investigate the key parameters associated with ranking 'vehicle safety' as the most important consideration in the new vehicle purchase. Participants recruited in Sweden and Spain completed a questionnaire about their new vehicle purchase. The findings from the questionnaire indicated that participants ranked safety-related factors (e.g., EuroNCAP (or other) safety ratings) as more important in the new vehicle purchase process than other vehicle factors (e.g., price, reliability etc.). Similarly, participants ranked safety-related features (e.g., advanced braking systems, front passenger airbags etc.) as more important than non-safety-related features (e.g., route navigation systems, air-conditioning etc.). Consistent with previous research, most participants equated vehicle safety with the presence of specific vehicle safety features or technologies rather than vehicle crash safety/test results or crashworthiness. The key parameters associated with ranking 'vehicle safety' as the most important consideration in the new vehicle purchase were: use of EuroNCAP, gender and education level, age, drivers' concern about crash involvement, first vehicle purchase, annual driving distance, person for whom the vehicle was purchased, and traffic infringement history. The findings from this study are important for policy makers, manufacturers and other stakeholders to assist in setting priorities with regard to the promotion and publicity of vehicle safety features

A summary of EHV propulsion technology. [Electric and Hybrid Vehicle

Science.gov (United States)

Schwartz, H. J.

1983-01-01

While the battery used by an electric vehicle is the primary determinant of range, and to a lesser extent of performance, the design of the vehicle's propulsion system establishes its performance level and is the greatest contributor to its purchase price. Propulsion system weight, efficiency and cost are related to the specific combination of components used. Attention is given to the development status of the U.S. Department of Energy's Electric and Hybrid Vehicle Program, through which propulsion component and system design improvements have been made which promise weight savings of 35-50 percent, efficiency gains of 25 percent, and lower costs, when compared to the state of the art at the program's inception.

Lightweight Vehicle and Driver’s Whole-Body Models for Vibration Analysis

Science.gov (United States)

MdSah, Jamali; Taha, Zahari; Azwan Ismail, Khairul

2018-03-01

Vehicle vibration is a main factor for driving fatigue, discomfort and health problems. The ability to simulate the vibration characteristics in the vehicle and its effects on driver’s whole-body vibration will give significant advantages to designers especially on the vehicle development time and cost. However, it is difficult to achieve optimal condition of ride comfort and handling when using passive suspension system. This paper presents mathematical equations that can be used to describe the vibration characteristics of a lightweight electric vehicle that had been developed. The vehicle’s model was combined with the lumped-parameter model of driver to determine the whole-body vibration level when the vehicle is passing over a road hump using Matlab Simulink. The models were simulated at a constant speed and the results were compared with the experimental data. The simulated vibration level at the vehicle floor and seat were almost similar to the experimental vibration results. The suspension systems that are being used for the solar vehicle are able to reduce the vibration level due to the road hump. The models can be used to simulate and choose the optimal parameters for the suspensions.

Detection and 3d Modelling of Vehicles from Terrestrial Stereo Image Pairs

Science.gov (United States)

Coenen, M.; Rottensteiner, F.; Heipke, C.

2017-05-01

The detection and pose estimation of vehicles plays an important role for automated and autonomous moving objects e.g. in autonomous driving environments. We tackle that problem on the basis of street level stereo images, obtained from a moving vehicle. Processing every stereo pair individually, our approach is divided into two subsequent steps: the vehicle detection and the modelling step. For the detection, we make use of the 3D stereo information and incorporate geometric assumptions on vehicle inherent properties in a firstly applied generic 3D object detection. By combining our generic detection approach with a state of the art vehicle detector, we are able to achieve satisfying detection results with values for completeness and correctness up to more than 86%. By fitting an object specific vehicle model into the vehicle detections, we are able to reconstruct the vehicles in 3D and to derive pose estimations as well as shape parameters for each vehicle. To deal with the intra-class variability of vehicles, we make use of a deformable 3D active shape model learned from 3D CAD vehicle data in our model fitting approach. While we achieve encouraging values up to 67.2% for correct position estimations, we are facing larger problems concerning the orientation estimation. The evaluation is done by using the object detection and orientation estimation benchmark of the KITTI dataset (Geiger et al., 2012).

Performance Evaluation of the Combined Agent Fire Fighting System (CAFFS)

National Research Council Canada - National Science Library

Kalberer, Jennifer

2003-01-01

... of the location. The Combined Agent Fire Fighting System (CAFFS) employs innovations in nozzle design, lightweight composites and combination agents to design a system with extinguishment capabilities of much larger ARFF vehicles...

Real-time people and vehicle detection from UAV imagery

Science.gov (United States)

Gaszczak, Anna; Breckon, Toby P.; Han, Jiwan

2011-01-01

A generic and robust approach for the real-time detection of people and vehicles from an Unmanned Aerial Vehicle (UAV) is an important goal within the framework of fully autonomous UAV deployment for aerial reconnaissance and surveillance. Here we present an approach for the automatic detection of vehicles based on using multiple trained cascaded Haar classifiers with secondary confirmation in thermal imagery. Additionally we present a related approach for people detection in thermal imagery based on a similar cascaded classification technique combining additional multivariate Gaussian shape matching. The results presented show the successful detection of vehicle and people under varying conditions in both isolated rural and cluttered urban environments with minimal false positive detection. Performance of the detector is optimized to reduce the overall false positive rate by aiming at the detection of each object of interest (vehicle/person) at least once in the environment (i.e. per search patter flight path) rather than every object in each image frame. Currently the detection rate for people is ~70% and cars ~80% although the overall episodic object detection rate for each flight pattern exceeds 90%.

Considering Variable Road Geometry in Adaptive Vehicle Speed Control

Directory of Open Access Journals (Sweden)

Xinping Yan

2013-01-01

Full Text Available Adaptive vehicle speed control is critical for developing Advanced Driver Assistance Systems (ADAS. Vehicle speed control considering variable road geometry has become a hotspot in ADAS research. In this paper, first, an exploration of intrinsic relationship between vehicle operation and road geometry is made. Secondly, a collaborative vehicle coupling model, a road geometry model, and an AVSC, which can respond to variable road geometry in advance, are developed. Then, based on H∞ control method and the minimum energy principle, a performance index is specified by a cost function for the proposed AVSC, which can explicitly consider variable road geometry in its optimization process. The proposed AVSC is designed by the Hamilton-Jacobi Inequality (HJI. Finally, simulations are carried out by combining the vehicle model with the road geometry model, in an aim of minimizing the performance index of the AVSC. Analyses of the simulation results indicate that the proposed AVSC can automatically and effectively regulate speed according to variable road geometry. It is believed that the proposed AVSC can be used to improve the economy, comfort, and safety effects of current ADAS.

Fuel economy of hybrid fuel-cell vehicles

Science.gov (United States)

Ahluwalia, Rajesh K.; Wang, X.; Rousseau, A.

The potential improvement in fuel economy of a mid-size fuel-cell vehicle by combining it with an energy storage system has been assessed. An energy management strategy is developed and used to operate the direct hydrogen, pressurized fuel-cell system in a load-following mode and the energy storage system in a charge-sustaining mode. The strategy places highest priority on maintaining the energy storage system in a state where it can supply unanticipated boost power when the fuel-cell system alone cannot meet the power demand. It is found that downsizing a fuel-cell system decreases its efficiency on a drive cycle which is compensated by partial regenerative capture of braking energy. On a highway cycle with limited braking energy the increase in fuel economy with hybridization is small but on the stop-and-go urban cycle the fuel economy can improve by 27%. On the combined highway and urban drive cycles the fuel economy of the fuel-cell vehicle is estimated to increase by up to 15% by hybridizing it with an energy storage system.

Generalized dynamic model and control of ambiguous mono axial vehicle robot

Directory of Open Access Journals (Sweden)

Frantisek Duchon

2016-09-01

Full Text Available This article deals with the novel concept of ambiguous mono axial vehicle robot. Such robot is a combination of Segway and dicycle, which utilizes the advantages of each chassis. The advantage of dicycle is lower energy consumption during the movement and the higher safety of carried payload. The movable platform inside the ambiguous mono axial vehicle allows using the various sensors or devices. This will change the ambiguous mono axial vehicle to the Segway type robot. Both these modes are necessary to control in the stable mode to ensure the safety of the ambiguous mono axial vehicle’s movement. The main contents of the article contain description of generalized dynamic model of ambiguous mono axial vehicle and related control of ambiguous mono axial vehicle. The proposal is unique in that the same controller is used for both modes. Several simulations verify proposed control schemes and identified parameters. Moreover, the dicycle type of platform has never been used in robotics and that is another novelty.

Vertical Take-Off and Landing Vehicle with Increased Cruise Efficiency

Science.gov (United States)

Fredericks, William J. (Inventor); Moore, Mark D. (Inventor); Busan, Ronald C. (Inventor); Rothhaar, Paul M. (Inventor); North, David D. (Inventor); Langford, William M. (Inventor); Laws, Christopher T. (Inventor); Hodges, William T. (Inventor); Johns, Zachary R. (Inventor); Webb, Sandy R. (Inventor)

2016-01-01

Systems, methods, and devices are provided that combine an advance vehicle configuration, such as an advanced aircraft configuration, with the infusion of electric propulsion, thereby enabling a four times increase in range and endurance while maintaining a full vertical takeoff and landing ("VTOL") and hover capability for the vehicle. Embodiments may provide vehicles with both VTOL and cruise efficient capabilities without the use of ground infrastructure. An embodiment vehicle may comprise a wing configured to tilt through a range of motion, a first series of electric motors coupled to the wing and each configured to drive an associated wing propeller, a tail configured to tilt through the range of motion, a second series of electric motors coupled to the tail and each configured to drive an associated tail propeller, and an electric propulsion system connected to the first series of electric motors and the second series of electric motors.

Special Aspects of Dynamic Properties of Combination Jet Effectors for Flying Vehicle Control

Directory of Open Access Journals (Sweden)

Val. V. Zelencov

2015-01-01

Full Text Available The paper considers an experimental study of special aspects of disturbed flow region dynamics that is formed when an injected high-pressure gas jet interacts with a supersonic crossflow of gas nearby a surface of a nozzle or a plate. The study objective was to determine a difference of the pressure distribution in the region and its sizes under dynamic action from stationary flow characteristics.The experiment involved measuring pressure distribution on the surface of a nozzle or a plate along with high-speed filming of the flow.The study has revealed that the difference in size of the disturbed flow region and the flow distribution is observed only in transition segments: under injected jet stagnation pressure increase or decrease. The region is formed with a time lag close to zero under pulsation frequencies used. The disturbed flow region size and boundary shape and pressure distribution in constant pressure segment are independent of jet pulsation.It was determined that the dynamic properties (i.e. time of formation of disturbed flow region depend of induced force and crossflow properties.Disturbed flow region size behavior in time domain can be represented by an aperiodic element with a time constant significantly smaller than that of the gas-feed circuit.The results gained make it possible to state that in assessing dynamic properties of combination jet effectors it is sufficient to take into account gas generator and gas-feed circuit which response is significantly slower than that of the disturbed flow region.The recommendations based on the study results can be used for supersonic and hypersonic flying vehicle design.

Does Driving Range of Electric Vehicles Influence Electric Vehicle Adoption?

Directory of Open Access Journals (Sweden)

Seiho Kim

2017-10-01

Full Text Available This study aims to determine the influential factors on the market share of electric vehicles through panel data analysis based on time series data from 2011 to 2015 in 31 countries. We selected five significant independent variables that are expected to affect electric vehicle adoption based on literature review. The econometric model in this study suggests that the relative price of electric vehicle compared to internal combustion engine vehicle, driving range, and number of models available in markets are correlated to the market share of electric vehicles. On the other hand, relationship between recharging infrastructure—an important factor for electric vehicle adoption in many studies—and market share of electric vehicles turned out to be insignificant in this study. From a political point of view, we argue that policy makers need to allocate more resources to research and development in order to extend driving range at the early stage of electric vehicle deployment in the markets.

A quantitative multiplex nuclease protection assay reveals immunotoxicity gene expression profiles in the rabbit model for vaginal drug safety evaluation

Energy Technology Data Exchange (ETDEWEB)

Fichorova, Raina N., E-mail: rfichorova@rics.bwh.harvard.edu [Laboratory of Genital Tract Biology, Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women' s Hospital and Harvard Medical School, Boston, MA (United States); Mendonca, Kevin; Yamamoto, Hidemi S.; Murray, Ryan [Laboratory of Genital Tract Biology, Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women' s Hospital and Harvard Medical School, Boston, MA (United States); Chandra, Neelima; Doncel, Gustavo F. [CONRAD, Department of Obstetrics and Gynecology, Eastern Virginia Medical School, Norfolk, VA (United States)

2015-06-15

Any vaginal product that alters the mucosal environment and impairs the immune barrier increases the risk of sexually transmitted infections, especially HIV infection, which thrives on mucosal damage and inflammation. The FDA-recommended rabbit vaginal irritation (RVI) model serves as a first line selection tool for vaginal products; however, for decades it has been limited to histopathology scoring, insufficient to select safe anti-HIV microbicides. In this study we incorporate to the RVI model a novel quantitative nuclease protection assay (qNPA) to quantify mRNA levels of 25 genes representing leukocyte differentiation markers, toll-like receptors (TLR), cytokines, chemokines, epithelial repair, microbicidal and vascular markers, by designing two multiplex arrays. Tissue sections were obtained from 36 rabbits (6 per treatment arm) after 14 daily applications of a placebo gel, saline, 4% nonoxynol-9 (N-9), and three combinations of the anti-HIV microbicides tenofovir (TFV) and UC781 in escalating concentrations (highest: 10% TFV + 2.5%UC781). Results showed that increased expression levels of toll-like receptor (TLR)-4, interleukin (IL)-1β, CXCL8, epithelial membrane protein (EMP)-1 (P < 0.05), and decreased levels of TLR2 (P < 0.05), TLR3 and bactericidal permeability increasing protein (BPI) (P < 0.001) were associated with cervicovaginal mucosal alteration (histopathology). Seven markers showed a significant linear trend predicting epithelial damage (up with CD4, IL-1β, CXCL8, CCL2, CCL21, EMP1 and down with BPI). Despite the low tissue damage RVI scores, the high-dose microbicide combination gel caused activation of HIV host cells (SLC and CD4) while N-9 caused proinflammatory gene upregulation (IL-8 and TLR4) suggesting a potential for increasing risk of HIV via different mechanisms depending on the chemical nature of the test product. - Highlights: • A transcriptome nuclease protection assay assessed microbicides for vaginal safety. • Biomarkers were

A quantitative multiplex nuclease protection assay reveals immunotoxicity gene expression profiles in the rabbit model for vaginal drug safety evaluation

International Nuclear Information System (INIS)

Fichorova, Raina N.; Mendonca, Kevin; Yamamoto, Hidemi S.; Murray, Ryan; Chandra, Neelima; Doncel, Gustavo F.

2015-01-01

Any vaginal product that alters the mucosal environment and impairs the immune barrier increases the risk of sexually transmitted infections, especially HIV infection, which thrives on mucosal damage and inflammation. The FDA-recommended rabbit vaginal irritation (RVI) model serves as a first line selection tool for vaginal products; however, for decades it has been limited to histopathology scoring, insufficient to select safe anti-HIV microbicides. In this study we incorporate to the RVI model a novel quantitative nuclease protection assay (qNPA) to quantify mRNA levels of 25 genes representing leukocyte differentiation markers, toll-like receptors (TLR), cytokines, chemokines, epithelial repair, microbicidal and vascular markers, by designing two multiplex arrays. Tissue sections were obtained from 36 rabbits (6 per treatment arm) after 14 daily applications of a placebo gel, saline, 4% nonoxynol-9 (N-9), and three combinations of the anti-HIV microbicides tenofovir (TFV) and UC781 in escalating concentrations (highest: 10% TFV + 2.5%UC781). Results showed that increased expression levels of toll-like receptor (TLR)-4, interleukin (IL)-1β, CXCL8, epithelial membrane protein (EMP)-1 (P < 0.05), and decreased levels of TLR2 (P < 0.05), TLR3 and bactericidal permeability increasing protein (BPI) (P < 0.001) were associated with cervicovaginal mucosal alteration (histopathology). Seven markers showed a significant linear trend predicting epithelial damage (up with CD4, IL-1β, CXCL8, CCL2, CCL21, EMP1 and down with BPI). Despite the low tissue damage RVI scores, the high-dose microbicide combination gel caused activation of HIV host cells (SLC and CD4) while N-9 caused proinflammatory gene upregulation (IL-8 and TLR4) suggesting a potential for increasing risk of HIV via different mechanisms depending on the chemical nature of the test product. - Highlights: • A transcriptome nuclease protection assay assessed microbicides for vaginal safety. • Biomarkers were

Increased Dapivirine tissue accumulation through vaginal film codelivery of dapivirine and Tenofovir.

Science.gov (United States)

Akil, Ayman; Devlin, Brid; Cost, Marilyn; Rohan, Lisa Cencia

2014-05-05

The HIV-1 replication inhibitor dapivirine (DPV) is one of the most promising drug candidates being used in topical microbicide products for prevention of HIV-1 sexual transmission. To be able to block HIV-1 replication, DPV must have access to the viral reverse transcriptase enzyme. The window for DPV to access the enzyme happens during the HIV-1 cellular infection cycle. Thus, in order for DPV to exert its anti-HIV activity, it must be present in the mucosal tissue or cells where HIV-1 infection occurs. A dosage form containing DPV must be able to deliver the drug to the tissue site of action. Polymeric films are solid dosage forms that dissolve and release their payload upon contact with fluids. Films have been used as vaginal delivery systems of topical microbicide drug candidates including DPV. For use in topical microbicide products containing DPV, polymeric films must prove their ability to deliver DPV to the target tissue site of action. Ex vivo exposure studies of human ectocervical tissue to DPV film revealed that DPV was released from the film and did diffuse into the tissue in a concentration dependent manner indicating a process of passive diffusion. Analysis of drug distribution in the tissue revealed that DPV accumulated mostly at the basal layer of the epithelium infiltrating the upper part of the stroma. Furthermore, as a combination microbicide product, codelivery of DPV and TFV from a polymeric film resulted in a significant increase in DPV tissue concentration [14.21 (single entity film) and 31.03 μg/g (combination film)], whereas no impact on TFV tissue concentration was found. In vitro release experiments showed that this observation was due to a more rapid DPV release from the combination film as compared to the single entity film. In conclusion, the findings of this study confirm the ability of polymeric films to deliver DPV and TFV to human ectocervical tissue and show that codelivery of the two agents has a significant impact on DPV

Stereo-vision-based cooperative-vehicle positioning using OCC and neural networks

Science.gov (United States)

Ifthekhar, Md. Shareef; Saha, Nirzhar; Jang, Yeong Min

2015-10-01

Vehicle positioning has been subjected to extensive research regarding driving safety measures and assistance as well as autonomous navigation. The most common positioning technique used in automotive positioning is the global positioning system (GPS). However, GPS is not reliably accurate because of signal blockage caused by high-rise buildings. In addition, GPS is error prone when a vehicle is inside a tunnel. Moreover, GPS and other radio-frequency-based approaches cannot provide orientation information or the position of neighboring vehicles. In this study, we propose a cooperative-vehicle positioning (CVP) technique by using the newly developed optical camera communications (OCC). The OCC technique utilizes image sensors and cameras to receive and decode light-modulated information from light-emitting diodes (LEDs). A vehicle equipped with an OCC transceiver can receive positioning and other information such as speed, lane change, driver's condition, etc., through optical wireless links of neighboring vehicles. Thus, the target vehicle position that is too far away to establish an OCC link can be determined by a computer-vision-based technique combined with the cooperation of neighboring vehicles. In addition, we have devised a back-propagation (BP) neural-network learning method for positioning and range estimation for CVP. The proposed neural-network-based technique can estimate target vehicle position from only two image points of target vehicles using stereo vision. For this, we use rear LEDs on target vehicles as image points. We show from simulation results that our neural-network-based method achieves better accuracy than that of the computer-vision method.

Commute Equilibrium for Mixed Networks with Autonomous Vehicles and Traditional Vehicles

Directory of Open Access Journals (Sweden)

Yangbeibei Ji

2017-01-01

Full Text Available Recent development of autonomous vehicle (AV provides new travel opportunities for citizens, and traditional vehicles (TVs will still be used for a long time. Therefore, it is highly possible that both AVs and TVs will be used as travel modes in a city. In a transportation system with both AVs and TVs, the traffic pattern is worthy of studying. This paper investigates user equilibrium traffic pattern based on the traditional bottleneck model considering AVs and TVs. For both TVs and AVs, travel costs include queuing delay and schedule delay. However, they also have different components of travel costs; more specifically, for AVs, passengers have to pay a riding fare, and, for TVs, travelers encounter a walking time cost after parking their cars. For different combinations of travel demands and riding fare of AVs, analytical solutions of three different user equilibrium traffic patterns are obtained. Finally, numerical examples are provided to demonstrate the usefulness of the analytical models. Sensitivity analyses are examined to show the impacts of AV’s time-dependent fee and trip-based fixed fee on the traffic pattern and travel costs.

Hybrid Aerial/Rover Vehicle

Science.gov (United States)

Bachelder, Aaron

2003-01-01

A proposed instrumented robotic vehicle called an "aerover" would fly, roll along the ground, and/or float on bodies of liquid, as needed. The aerover would combine features of an aerobot (a robotic lighter-than-air balloon) and a wheeled robot of the "rover" class. An aerover would also look very much like a variant of the "beach-ball" rovers. Although the aerover was conceived for use in scientific exploration of Titan (the largest moon of the planet Saturn), the aerover concept could readily be adapted to similar uses on Earth.

Studies of a Combined-Cycle Engine

OpenAIRE

苅田, 丈士; KANDA, Takeshi

2003-01-01

For a Single-Stage-to-Orbit (SSTO) aerospace plane (Fig.1), several engines will be necessary to reach orbit. The combined-cycle engine incorporates several operational modes in a single engine. Study of the combined cycle engine has a long history, and several kinds of such engines have been proposed and studied. When several engines are mounted on a vehicle, each engine of the system will show a performance higher than that of the combined cycle engine. However, during the operation of one ...

Using two detectors concurrently to monitor ambient dose equivalent rates in vehicle surveys of radiocesium contaminated land.

Science.gov (United States)

Takeishi, Minoru; Shibamichi, Masaru; Malins, Alex; Kurikami, Hiroshi; Murakami, Mitsuhiro; Saegusa, Jun; Yoneya, Masayuki

2017-10-01

In response to the accident at Tokyo Electric Power Company's Fukushima Dai-ichi Nuclear Power Plant (FDNPP), vehicle-borne monitoring was used to map radiation levels for radiological protection of the public. By convention measurements from vehicle-borne surveys are converted to the ambient dose equivalent rate at 1 m height in the absence of the vehicle. This allows for comparison with results from other types of survey, including surveys with hand-held or airborne instruments. To improve the accuracy of the converted results from vehicle-borne surveys, we investigated combining measurements from two detectors mounted on the vehicle at different heights above the ground. A dual-detector setup was added to a JAEA monitoring car and compared against hand-held survey meter measurements in Fukushima Prefecture. The results obtained by combining measurements from two detectors were within ±20% of the hand-held reference measurements. The mean absolute percentage deviation from the reference measurements was 7.2%. The combined results from the two detectors were more accurate than those from either the roof-mounted detector, or the detector inside the vehicle, taken alone. One issue with vehicle-borne surveys is that ambient dose equivalent rates above roads are not necessarily representative of adjacent areas. This is because radiocesium is often deficient on asphalt surfaces, as it is easily scrubbed off by rain, wind and vehicle tires. To tackle this issue, we investigated mounting heights for vehicle-borne detectors using Monte Carlo gamma-ray simulations. When radiocesium is deficient on a road compared to the adjacent land, mounting detectors high on vehicles yields results closer to the values adjacent to the road. The ratio of ambient dose equivalent rates reported by detectors mounted at different heights in a dual-detector setup indicates whether radiocesium is deficient on the road compared to the adjacent land. Copyright © 2017 Elsevier Ltd. All rights

Traffic control and intelligent vehicle highway systems: a survey

NARCIS (Netherlands)

Baskar, L.D.; Schutter, B. de; Hellendoorn, J.; Papp, Z.

2011-01-01

Traffic congestion in highway networks is one of the main issues to be addressed by today's traffic management schemes. Automation combined with the increasing market penetration of on-line communication, navigation and advanced driver assistance systems will ultimately result in intelligent vehicle

SOA formation from gasoline vehicles: from the tailpipe to the atmosphere

Science.gov (United States)

Robinson, A. L.; Zhao, Y.; Lambe, A. T.; Saleh, R.; Saliba, G.; Tkacik, D. S.

2017-12-01

Secondary organic aerosol (SOA) formation from gasoline vehicles has been indicated as an important source of atmospheric SOA, but its contribution to atmospheric SOA is loosely constrained due to the lack of measurements to link SOA formation from the tailpipe to atmospheric SOA. In this study, we determine the contribution of SOA formation based on measurements made with a Potential Aerosol Mass (PAM) oxidation flow reactor by oxidizing vehicular exhaust and ambient air. We first investigate SOA formation from dilute gasoline-vehicle exhaust during chassis dynamometer testing. The test fleet consists of both vehicles equipped with gasoline direct injection engines (GDI vehicles) and those equipped with port fuel injection engines (PFI vehicles). These vehicles span a wide range of emissions standards from Tier0 to Super Ultra-Low Emission Vehicles (SULEV). Then, we combine our measurements of SOA formation from gasoline vehicles during dynamometer testing with measurements of SOA formation using a PAM reactor conducted in a highway tunnel and in the unban atmosphere. Comparisons of SOA formation between these datasets enable us to quantitatively connect SOA formation from individual vehicles, to a large on-road fleet, and to the atmosphere. To facilitate the comparisons, we account for the effects of both the photochemical age and dilution on SOA formation. Our results show that SOA formation from gasoline vehicles can contribute over 50% of fossil fuel-related atmospheric SOA in the Los Angeles area. Furthermore, our results demonstrate that the tightening of emissions standards effectively reduces SOA formation from gasoline vehicles, including both PFI and GDI vehicles, if the atmospheric chemistry regime remains the same.

Study on the Vehicle Dynamic Load Considering the Vehicle-Pavement Coupled Effect

Science.gov (United States)

Xu, H. L.; He, L.; An, D.

2017-11-01

The vibration of vehicle-pavement interaction system is sophisticated random vibration process and the vehicle-pavement coupled effect was not considered in the previous study. A new linear elastic model of the vehicle-pavement coupled system was established in the paper. The new model was verified with field measurement which could reflect the real vibration between vehicle and pavement. Using the new model, the study on the vehicle dynamic load considering the vehicle-pavement coupled effect showed that random forces (centralization) between vehicle and pavement were influenced largely by vehicle-pavement coupled effect. Numerical calculation indicated that the maximum of random forces in coupled model was 2.4 times than that in uncoupled model. Inquiring the reason, it was found that the main vibration frequency of the vehicle non-suspension system was similar with that of the vehicle suspension system in the coupled model and the resonance vibration lead to vehicle dynamic load increase significantly.

Establishing bonds between vehicle certification data and real-world vehicle fuel consumption – A Vehicle Specific Power approach

International Nuclear Information System (INIS)

Duarte, G.O.; Gonçalves, G.A.; Baptista, P.C.; Farias, T.L.

2015-01-01

Highlights: • Innovative methodology to estimate VSP fuel consumption based on public available data. • Model validation with accurate fuel consumption results (absolute deviation from 4.7% to 9.2%). • Best-selling vehicles in Portugal case study was developed for different driving cycles. - Abstract: A method to perform the energy characterization of a vehicle according to the specific power required while driving was developed using public vehicle certification data. Using a portable emission measurement system, fuel consumption was quantified in a second-by-second basis under on-road conditions for 19 vehicles (spark-ignition, compression-ignition and hybrids). This data allowed building generic curves of fuel consumption as a function of the specific power, according to Vehicle Specific Power methodology. Comparing on-road measurements and the model estimates, a R 2 higher than 0.9 for conventional and hybrid vehicles was obtained regarding modal fuel consumption. Comparing the fuel consumption measured on the drive cycles performed by each vehicle and the correspondent estimates, an absolute deviation of 9.2% ± 9.2% was found for conventional vehicles and 4.7% ± 1.8% for hybrids vehicles. This methodology was validated and applied to estimate the energy impacts of the best-selling vehicles in Portugal for different driving cycles. This prompt method, that does not require vehicle monitoring, can estimate curves of fuel consumption in g/s, as a function of specific power, which allows quantifying the absolute fuel use for any driving cycle

Kalman and particle filtering methods for full vehicle and tyre identification

Science.gov (United States)

Bogdanski, Karol; Best, Matthew C.

2018-05-01

This paper considers identification of all significant vehicle handling dynamics of a test vehicle, including identification of a combined-slip tyre model, using only those sensors currently available on most vehicle controller area network buses. Using an appropriately simple but efficient model structure, all of the independent parameters are found from test vehicle data, with the resulting model accuracy demonstrated on independent validation data. The paper extends previous work on augmented Kalman Filter state estimators to concentrate wholly on parameter identification. It also serves as a review of three alternative filtering methods; identifying forms of the unscented Kalman filter, extended Kalman filter and particle filter are proposed and compared for effectiveness, complexity and computational efficiency. All three filters are suited to applications of system identification and the Kalman Filters can also operate in real-time in on-line model predictive controllers or estimators.

Rule-based energy management strategies for hybrid vehicles

NARCIS (Netherlands)

Hofman, T.; Druten, van R.M.; Serrarens, A.F.A.; Steinbuch, M.

2007-01-01

Int. J. of Electric and Hybrid Vehicles (IJEHV), The highest control layer of a (hybrid) vehicular drive train is termed the Energy Management Strategy (EMS). In this paper an overview of different control methods is given and a new rule-based EMS is introduced based on the combination of Rule-Based

Autonomous control of a locomotion vehicle

International Nuclear Information System (INIS)

Ichikawa, Yoshiaki; Senoh, Makoto; Miyata, Kenji

1984-01-01

A path planner and an execution system are proposed for autonomous vehicle control. The planner creates a near shortest path avoiding obstacles that are represented by combinations of circles and line segments on a two dimensional map. For realizing real time execution, path search procedures employ a heuristic pruning strategies in selecting a node to expand and in generating successor nodes. Nodes are selected for expansion in order, according to a cost assigned to each node. The cost is mainly evaluated by approximating a path length from the initial node to the goal node. In order to expand a node and to generate successor nodes, a specific search procedure is activated that finds positions avoiding obstacles in the direction of the goal, and creates successor nodes corresponding to the positions. The execution system, utilizing an ultrasonic range finder equipped to the vehicle performs a plan repair against unknown obstacles when echoes from the obstacles are observed. The plan repair is conducted by a map edition and replanning in such a way that new circles representing the echoes are added to the map. Obstacle avoidance tests with a vehicle controlled by microprocessors demonstrate the utility of heuristics just outlined. (author)

Heavy-Duty Vehicle Port Drayage Drive Cycle Characterization and Development: Preprint

Energy Technology Data Exchange (ETDEWEB)

Prohaska, Robert; Konan, Arnaud; Kelly, Kenneth; Lammert, Michael

2016-08-01

In an effort to better understand the operational requirements of port drayage vehicles and their potential for adoption of advanced technologies, National Renewable Energy Laboratory (NREL) researchers collected over 36,000 miles of in-use duty cycle data from 30 Class 8 drayage trucks operating at the Port of Long Beach and Port of Los Angeles in Southern California. These data include 1-Hz global positioning system location and SAE J1939 high-speed controller area network information. Researchers processed the data through NREL's Drive-Cycle Rapid Investigation, Visualization, and Evaluation tool to examine vehicle kinematic and dynamic patterns across the spectrum of operations. Using the k-medoids clustering method, a repeatable and quantitative process for multi-mode drive cycle segmentation, the analysis led to the creation of multiple drive cycles representing four distinct modes of operation that can be used independently or in combination. These drive cycles are statistically representative of real-world operation of port drayage vehicles. When combined with modeling and simulation tools, these representative test cycles allow advanced vehicle or systems developers to efficiently and accurately evaluate vehicle technology performance requirements to reduce cost and development time while ultimately leading to the commercialization of advanced technologies that meet the performance requirements of the port drayage vocation. The drive cycles, which are suitable for chassis dynamometer testing, were compared to several existing test cycles. This paper presents the clustering methodology, accompanying results of the port drayage duty cycle analysis and custom drive cycle creation.

Stability of the Small Electric Vehicle with Two In-Wheel Motors

Directory of Open Access Journals (Sweden)

Heerwan P.M.

2017-01-01

Full Text Available For a small electric vehicle (EV with the rear two in-wheel motors, the hydraulic brake system and the mechanical brake system are installed at the front and rear tire respectively. The mechanical brake system is used at the rear tire because there is no enough space for the hydraulic brake system. In a braking condition, the in-wheel motor at the rear tire will generate the regenerative braking force and it can improve the braking performance of the vehicle. However, during braking on the low adhesion road surface, anti-lock brake system (ABS is very crucial to prevent the tire from lock-up. To improve the safety and stability of the vehicle, the combination of anti-skid control system and direct yaw moment control system is proposed. The anti-skid control system contains a hydraulic unit of ABS at the front tires and regenerative brake timing control at the rear tires. The control method of the regenerative brake timing control is same as ABS and it will turn on and off to prevent the tire from lock-up. On the other hand, the direct yaw moment control system is developed to increase the steer performance of the vehicle. The optimal control is used as the control strategy method to control the yaw moment. The simulation is developed in MATLAB Simulink and the result shows that the proposed model can improve the stopping distance from 9 seconds to 8.2 seconds. In addition, the combination of skid control and yaw moment control also improved the steer performance of the vehicle.

Historic and projected vehicle use and carbon dioxide emissions

International Nuclear Information System (INIS)

Anon.

1990-01-01

Data are presented in this chapter that show a decline in total carbon dioxide emissions per vehicle of about 20 between 1970 and 1987. However, it is also shown that the fuel economy gains of the 1970s and early 1980s in many countries have begun to erode. In the US, low fuel prices combined with a failure to strengthen fuel efficiency standards have led to recent declines in new-car fuel efficiency. Even if these trends are reversed carbon dioxide in the transport sector will not be reduced if over all motor vehicle use continues along present lines

Vehicle State Estimator based regenerative braking implementation on an electric vehicle to improve lateral vehicle stability

NARCIS (Netherlands)

Jansen, S.T.H.; van Boekel, J.J.P.; Iersel, van S.S.; Besselink, I.J.M.; Nijmeijer, H.

2013-01-01

The driving range of electric vehicles can be extended using regenerative braking. Regenerative braking uses the electric drive system, and therefore only the driven wheels, for decelerating the vehicle. Braking on one axle affects the stability of the vehicle, especially for road conditions with

Vehicle state estimator based regenerative braking implementation on an electric vehicle to improve lateral vehicle stability

NARCIS (Netherlands)

Jansen, S.T.H.; Boekel, J.J.P. van; Iersel, S.S. van; Besselink, I.J.M.; Nijmeijer, H.

2013-01-01

The driving range of electric vehicles can be extended using regenerative braking. Regenerative braking uses the elctric drive system, and therefore only the driven wheels, for decelerating the vehicle. Braking on one axle affects the stability of the vehicle, especially for road conditions with

Simulating the value of electric-vehicle-grid integration using a behaviourally realistic model

Science.gov (United States)

Wolinetz, Michael; Axsen, Jonn; Peters, Jotham; Crawford, Curran

2018-02-01

Vehicle-grid integration (VGI) uses the interaction between electric vehicles and the electrical grid to provide benefits that may include reducing the cost of using intermittent renwable electricity or providing a financial incentive for electric vehicle ownerhip. However, studies that estimate the value of VGI benefits have largely ignored how consumer behaviour will affect the magnitude of the impact. Here, we simulate the long-term impact of VGI using behaviourally realistic and empirically derived models of vehicle adoption and charging combined with an electricity system model. We focus on the case where a central entity manages the charging rate and timing for participating electric vehicles. VGI is found not to increase the adoption of electric vehicles, but does have a a small beneficial impact on electricity prices. By 2050, VGI reduces wholesale electricity prices by 0.6-0.7% (0.7 MWh-1, 2010 CAD) relative to an equivalent scenario without VGI. Excluding consumer behaviour from the analysis inflates the value of VGI.

Driving the Phileas, a new automated public transport vehicle

NARCIS (Netherlands)

de Waard, Dick; Brookhuis, Karel; Fabriek, Eva; Van Wolffelaar, Peter C.

2004-01-01

Phileas is a high quality public transport vehicle combining characteristics of bus, tram, and the underground. Phileas is equipped with pneumatic tyres and complies with the statutory regulations for buses. Accordingly Phileas may drive everywhere on public roads where buses are allowed to drive.

41 CFR 102-34.85 - What motor vehicles require motor vehicle identification?

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What motor vehicles require motor vehicle identification? 102-34.85 Section 102-34.85 Public Contracts and Property Management... 34-MOTOR VEHICLE MANAGEMENT Identifying and Registering Motor Vehicles Motor Vehicle Identification...

Vehicle to Vehicle Services

DEFF Research Database (Denmark)

Brønsted, Jeppe Rørbæk

2008-01-01

location aware infotainment, increase safety, and lessen environmental strain. This dissertation is about service oriented architecture for pervasive computing with an emphasis on vehicle to vehicle applications. If devices are exposed as services, applications can be created by composing a set of services...... be evaluated. Service composition mechanisms for pervasive computing are categorized and we discuss how the characteristics of pervasive computing can be supported by service composition mechanisms. Finally, we investigate how to make pervasive computing systems capable of being noticed and understood...

Vehicle barrier systems

International Nuclear Information System (INIS)

Sena, P.A.

1986-01-01

The ground vehicle is one of the most effective tools available to an adversary force. Vehicles can be used to penetrate many types of perimeter barriers, transport equipment and personnel rapidly over long distances, and deliver large amounts of explosives directly to facilities in suicide missions. The function of a vehicle barrier system is to detain or disable a defined threat vehicle at a selected distance from a protected facility. Numerous facilities are installing, or planning to install, vehicle barrier systems and many of these facilities are requesting guidance to do so adequately. Therefore, vehicle barriers are being evaluated to determine their stopping capabilities so that systems can be designed that are both balanced and capable of providing a desired degree of protection. Equally important, many of the considerations that should be taken into account when establishing a vehicle barrier system have been identified. These considerations which pertain to site preparation, barrier selection, system integration and operation, and vehicle/barrier interaction, are discussed in this paper

Concept of intellectual charging system for electrical and plug-in hybrid vehicles in Russian Federation

Science.gov (United States)

Kolbasov, A.; Karpukhin, K.; Terenchenko, A.; Kavalchuk, I.

2018-02-01

Electric vehicles have become the most common solution to improve sustainability of the transportation systems all around the world. Despite all benefits, wide adaptation of electric vehicles requires major changes in the infrastructure, including grid adaptation to the rapidly increased power demand and development of the Connected Car concept. This paper discusses the approaches to improve usability of electric vehicles, by creating suitable web-services, with possible connections vehicle-to-vehicle, vehicle-to-infrastructure, and vehicle-to-grid. Developed concept combines information about electrical loads on the grid in specific direction, navigation information from the on-board system, existing and empty charging slots and power availability. In addition, this paper presents the universal concept of the photovoltaic integrated charging stations, which are connected to the developed information systems. It helps to achieve rapid adaptation of the overall infrastructure to the needs of the electric vehicles users with minor changes in the existing grid and loads.

Direct hydrogen fuel cell systems for hybrid vehicles

Science.gov (United States)

Ahluwalia, Rajesh K.; Wang, X.

Hybridizing a fuel cell system with an energy storage system offers an opportunity to improve the fuel economy of the vehicle through regenerative braking and possibly to increase the specific power and decrease the cost of the combined energy conversion and storage systems. Even in a hybrid configuration it is advantageous to operate the fuel cell system in a load-following mode and use the power from the energy storage system when the fuel cell alone cannot meet the power demand. This paper discusses an approach for designing load-following fuel cell systems for hybrid vehicles and illustrates it by applying it to pressurized, direct hydrogen, polymer-electrolyte fuel cell (PEFC) systems for a mid-size family sedan. The vehicle level requirements relative to traction power, response time, start-up time and energy conversion efficiency are used to select the important parameters for the PEFC stack, air management system, heat rejection system and the water management system.

Nonlinear Output Feedback Control of Underwater Vehicle Propellers using Advance Speed Feedback

DEFF Research Database (Denmark)

Fossen, T.I.; Blanke, M.

1999-01-01

More accurate propeller shaft speed controllers can be designed by using nonlinear control theory. In this paper, an output feedback controller reconstructing the advance speed (speed of water going into the propeller) from vehicle speed measurements is derived. For this purpose a three-state model...... minimizes thruster losses due to variations in propeller axial inlet flow which is a major problem when applying conventional vehicle-propeller control systems. The proposed controller is simulated for an underwater vehicle equipped with a single propeller. From the simulations it can be concluded...... of propeller shaft speed, forward (surge) speed of the vehicle and axial inlet flow of the propeller is applied. A nonlinear observer in combination with an output feedback integral controller are derived by applying Lyapunov stability theory and exponential stability is proven. The output feedback controller...

Pharmacokinetics of 2 dapivirine vaginal microbicide gels and their safety vs. Hydroxyethyl cellulose-based universal placebo gel.

Science.gov (United States)

Nel, Annalene M; Smythe, Shanique C; Habibi, Sepideh; Kaptur, Paulina E; Romano, Joseph W

2010-10-01

Dapivirine, a nonnucleoside reverse transcriptase inhibitor, is in development as a microbicide for the protection of women against HIV infection. A randomized, double-blind, phase 1 trial was conducted in 36 healthy HIV-negative women to compare the pharmacokinetics of 2 dapivirine vaginal gel formulations (0.05% each) and their safety with the hydroxyethyl cellulose-based universal placebo gel. Gel was self-administered once daily for a total of 11 days. Blood and vaginal fluid samples were collected sequentially over 24 days for pharmacokinetic analysis. Safety was evaluated by pelvic examination, colposcopy, adverse events, and clinical laboratory assessments. Adverse event profiles were similar for the 3 gels. Most events were mild and not related to study gel. Headache and vaginal hemorrhage (any vaginal bleeding) were most common. Plasma concentrations of dapivirine did not exceed 1.1 ng/mL. Steady-state conditions were reached within approximately 10 days. Dapivirine concentrations in vaginal fluids were slightly higher for Gel 4789, but Cmax values on days 1 and 14 were not significantly different. Terminal half-life was 72-73 hours in plasma and 15-17 hours in vaginal fluids. Both formulations of dapivirine gel were safe and well tolerated. Dapivirine was delivered to the lower genital tract at concentrations at least 5 logs greater than in vitro inhibitory concentrations.

Candidate Microbicides Block HIV-1 Infection of Human Immature Langerhans Cells within Epithelial Tissue Explants

Science.gov (United States)

Kawamura, Tatsuyoshi; Cohen, Sandra S.; Borris, Debra L.; Aquilino, Elisabeth A.; Glushakova, Svetlana; Margolis, Leonid B.; Orenstein, Jan M.; Offord, Robin E.; Neurath, A. Robert; Blauvelt, Andrew

2000-01-01

Initial biologic events that underlie sexual transmission of HIV-1 are poorly understood. To model these events, we exposed human immature Langerhans cells (LCs) within epithelial tissue explants to two primary and two laboratory-adapted HIV-1 isolates. We detected HIV-1Ba-L infection in single LCs that spontaneously emigrated from explants by flow cytometry (median of infected LCs = 0.52%, range = 0.08–4.77%). HIV-1–infected LCs downregulated surface CD4 and CD83, whereas MHC class II, CD80, and CD86 were unchanged. For all HIV-1 strains tested, emigrated LCs were critical in establishing high levels of infection (0.1–1 μg HIV-1 p24 per milliliter) in cocultured autologous or allogeneic T cells. HIV-1Ba-L (an R5 HIV-1 strain) more efficiently infected LC–T cell cocultures when compared with HIV-1IIIB (an X4 HIV-1 strain). Interestingly, pretreatment of explants with either aminooxypentane-RANTES (regulated upon activation, normal T cell expressed and secreted) or cellulose acetate phthalate (potential microbicides) blocked HIV-1 infection of LCs and subsequent T cell infection in a dose-dependent manner. In summary, we document HIV-1 infection in single LCs after exposure to virus within epithelial tissue, demonstrate that relatively low numbers of these cells are capable of inducing high levels of infection in cocultured T cells, and provide a useful explant model for testing of agents designed to block sexual transmission of HIV-1. PMID:11085750

Connected vehicle applications : safety.

Science.gov (United States)

2016-01-01

Connected vehicle safety applications are designed to increase situational awareness : and reduce or eliminate crashes through vehicle-to-infrastructure, vehicle-to-vehicle, : and vehicle-to-pedestrian data transmissions. Applications support advisor...

Program description for the program Demonstration program for electric vehicles 2011-2015; Programbeskrivning foer programmet Demonstrationsprogram foer elfordon 2011-2015

Energy Technology Data Exchange (ETDEWEB)

2011-04-15

The program's efforts aim at, firstly, from a user perspective identify and possibly eliminate barriers for large-scale introduction of electric vehicles on the Swedish market. Through various research activities based in the real environment experience may be drawn from both vehicle use and different types of behavior. Infrastructure tests on a sufficient scale give the combined effect of real-life test environments for the combination of vehicles and charging environments as well as a base for experiences of softer issues around electric vehicles. Precisely these behavioral experiences are difficult to reach via the related but more technically focused programs such as, FFI (Vehicle strategic research and innovation) and Energy efficient road vehicles. Several systems for electrification of vehicles exist today, and further initiatives for solutions are on the way. It is therefore very important to examine which systems give the highest total energy efficiency. It is also relevant for these different systems in a real environment to explore the potentials and difficulties that may arise in larger implementations

Multi-Task Vehicle Detection with Region-of-Interest Voting.

Science.gov (United States)

Chu, Wenqing; Liu, Yao; Shen, Chen; Cai, Deng; Hua, Xian-Sheng

2017-10-12

Vehicle detection is a challenging problem in autonomous driving systems, due to its large structural and appearance variations. In this paper, we propose a novel vehicle detection scheme based on multi-task deep convolutional neural networks (CNN) and region-of-interest (RoI) voting. In the design of CNN architecture, we enrich the supervised information with subcategory, region overlap, bounding-box regression and category of each training RoI as a multi-task learning framework. This design allows the CNN model to share visual knowledge among different vehicle attributes simultaneously, thus detection robustness can be effectively improved. In addition, most existing methods consider each RoI independently, ignoring the clues from its neighboring RoIs. In our approach, we utilize the CNN model to predict the offset direction of each RoI boundary towards the corresponding ground truth. Then each RoI can vote those suitable adjacent bounding boxes which are consistent with this additional information. The voting results are combined with the score of each RoI itself to find a more accurate location from a large number of candidates. Experimental results on the real-world computer vision benchmarks KITTI and the PASCAL2007 vehicle dataset show that our approach achieves superior performance in vehicle detection compared with other existing published works.

Novel vehicle detection system based on stacked DoG kernel and AdaBoost

Science.gov (United States)

Kang, Hyun Ho; Lee, Seo Won; You, Sung Hyun

2018-01-01

This paper proposes a novel vehicle detection system that can overcome some limitations of typical vehicle detection systems using AdaBoost-based methods. The performance of the AdaBoost-based vehicle detection system is dependent on its training data. Thus, its performance decreases when the shape of a target differs from its training data, or the pattern of a preceding vehicle is not visible in the image due to the light conditions. A stacked Difference of Gaussian (DoG)–based feature extraction algorithm is proposed to address this issue by recognizing common characteristics, such as the shadow and rear wheels beneath vehicles—of vehicles under various conditions. The common characteristics of vehicles are extracted by applying the stacked DoG shaped kernel obtained from the 3D plot of an image through a convolution method and investigating only certain regions that have a similar patterns. A new vehicle detection system is constructed by combining the novel stacked DoG feature extraction algorithm with the AdaBoost method. Experiments are provided to demonstrate the effectiveness of the proposed vehicle detection system under different conditions. PMID:29513727

Climate Control Load Reduction Strategies for Electric Drive Vehicles in Warm Weather

Energy Technology Data Exchange (ETDEWEB)

Jeffers, M. A.; Chaney, L.; Rugh, J. P.

2015-04-30

Passenger compartment climate control is one of the largest auxiliary loads on a vehicle. Like conventional vehicles, electric vehicles (EVs) require climate control to maintain occupant comfort and safety, but cabin heating and air conditioning have a negative impact on driving range for all electric vehicles. Range reduction caused by climate control and other factors is a barrier to widespread adoption of EVs. Reducing the thermal loads on the climate control system will extend driving range, thereby reducing consumer range anxiety and increasing the market penetration of EVs. Researchers at the National Renewable Energy Laboratory have investigated strategies for vehicle climate control load reduction, with special attention toward EVs. Outdoor vehicle thermal testing was conducted on two 2012 Ford Focus Electric vehicles to evaluate thermal management strategies for warm weather, including solar load reduction and cabin pre-ventilation. An advanced thermal test manikin was used to assess a zonal approach to climate control. In addition, vehicle thermal analysis was used to support testing by exploring thermal load reduction strategies, evaluating occupant thermal comfort, and calculating EV range impacts. Through stationary cooling tests and vehicle simulations, a zonal cooling configuration demonstrated range improvement of 6%-15%, depending on the drive cycle. A combined cooling configuration that incorporated thermal load reduction and zonal cooling strategies showed up to 33% improvement in EV range.

Vehicle following controller design for autonomous intelligent vehicles

Science.gov (United States)

Chien, C. C.; Lai, M. C.; Mayr, R.

1994-01-01

A new vehicle following controller is proposed for autonomous intelligent vehicles. The proposed vehicle following controller not only provides smooth transient maneuvers for unavoidable nonzero initial conditions but also guarantees the asymptotic platoon stability without the availability of feedforward information. Furthermore, the achieved asymptotic platoon stability is shown to be robust to sensor delays and an upper bound for the allowable sensor delays is also provided in this paper.

Light vehicle crash avoidance needs and countermeasure profiles for safety applications based on vehicle-to-vehicle communications

Science.gov (United States)

2013-04-30

This report discusses light-vehicle crash countermeasure profiles and functions for five target pre-crash scenario groups based on vehicle-to-vehicle (V2V) communications. Target pre-crash scenario groups include rear-end, lane change, opposite direc...

Combining stated and revealed choice research to simulate the neighbor effect: The case of hybrid-electric vehicles

Energy Technology Data Exchange (ETDEWEB)

Axsen, Jonn [Institute of Transportation Studies, Univ. of California at Davis, 2028 Academic Surge, One Shields Avenue, Davis, CA 95616 (United States); Mountain, Dean C. [DeGroote School of Business, McMaster Univ., 1280 Main Street West, Hamilton, ON L8S 4M4 (Canada); Jaccard, Mark [School of Resource and Environmental Management, Simon Fraser Univ., 8888 Univ. Drive, Burnaby, BC V5A 1S6 (Canada)

2009-08-15

According to intuition and theories of diffusion, consumer preferences develop along with technological change. However, most economic models designed for policy simulation unrealistically assume static preferences. To improve the behavioral realism of an energy-economy policy model, this study investigates the ''neighbor effect'', where a new technology becomes more desirable as its adoption becomes more widespread in the market. We measure this effect as a change in aggregated willingness to pay under different levels of technology penetration. Focusing on hybrid-electric vehicles (HEVs), an online survey experiment collected stated preference (SP) data from 535 Canadian and 408 Californian vehicle owners under different hypothetical market conditions. Revealed preference (RP) data was collected from the same respondents by eliciting the year, make and model of recent vehicle purchases from regions with different degrees of HEV popularity: Canada with 0.17% new market share, and California with 3.0% new market share. We compare choice models estimated from RP data only with three joint SP-RP estimation techniques, each assigning a different weight to the influence of SP and RP data in coefficient estimates. Statistically, models allowing more RP influence outperform SP influenced models. However, results suggest that because the RP data in this study is afflicted by multicollinearity, techniques that allow more SP influence in the beta estimates while maintaining RP data for calibrating vehicle class constraints produce more realistic estimates of willingness to pay. Furthermore, SP influenced coefficient estimates also translate to more realistic behavioral parameters for CIMS, allowing more sensitivity to policy simulations. (author)

Combining stated and revealed choice research to simulate the neighbor effect: The case of hybrid-electric vehicles

International Nuclear Information System (INIS)

Axsen, Jonn; Mountain, Dean C.; Jaccard, Mark

2009-01-01

According to intuition and theories of diffusion, consumer preferences develop along with technological change. However, most economic models designed for policy simulation unrealistically assume static preferences. To improve the behavioral realism of an energy-economy policy model, this study investigates the ''neighbor effect'', where a new technology becomes more desirable as its adoption becomes more widespread in the market. We measure this effect as a change in aggregated willingness to pay under different levels of technology penetration. Focusing on hybrid-electric vehicles (HEVs), an online survey experiment collected stated preference (SP) data from 535 Canadian and 408 Californian vehicle owners under different hypothetical market conditions. Revealed preference (RP) data was collected from the same respondents by eliciting the year, make and model of recent vehicle purchases from regions with different degrees of HEV popularity: Canada with 0.17% new market share, and California with 3.0% new market share. We compare choice models estimated from RP data only with three joint SP-RP estimation techniques, each assigning a different weight to the influence of SP and RP data in coefficient estimates. Statistically, models allowing more RP influence outperform SP influenced models. However, results suggest that because the RP data in this study is afflicted by multicollinearity, techniques that allow more SP influence in the beta estimates while maintaining RP data for calibrating vehicle class constraints produce more realistic estimates of willingness to pay. Furthermore, SP influenced coefficient estimates also translate to more realistic behavioral parameters for CIMS, allowing more sensitivity to policy simulations. (author)

Vehicle Classification Using an Imbalanced Dataset Based on a Single Magnetic Sensor

Directory of Open Access Journals (Sweden)

Chang Xu

2018-05-01

Full Text Available This paper aims to improve the accuracy of automatic vehicle classifiers for imbalanced datasets. Classification is made through utilizing a single anisotropic magnetoresistive sensor, with the models of vehicles involved being classified into hatchbacks, sedans, buses, and multi-purpose vehicles (MPVs. Using time domain and frequency domain features in combination with three common classification algorithms in pattern recognition, we develop a novel feature extraction method for vehicle classification. These three common classification algorithms are the k-nearest neighbor, the support vector machine, and the back-propagation neural network. Nevertheless, a problem remains with the original vehicle magnetic dataset collected being imbalanced, and may lead to inaccurate classification results. With this in mind, we propose an approach called SMOTE, which can further boost the performance of classifiers. Experimental results show that the k-nearest neighbor (KNN classifier with the SMOTE algorithm can reach a classification accuracy of 95.46%, thus minimizing the effect of the imbalance.

Vehicle Classification Using an Imbalanced Dataset Based on a Single Magnetic Sensor.

Science.gov (United States)

Xu, Chang; Wang, Yingguan; Bao, Xinghe; Li, Fengrong

2018-05-24

This paper aims to improve the accuracy of automatic vehicle classifiers for imbalanced datasets. Classification is made through utilizing a single anisotropic magnetoresistive sensor, with the models of vehicles involved being classified into hatchbacks, sedans, buses, and multi-purpose vehicles (MPVs). Using time domain and frequency domain features in combination with three common classification algorithms in pattern recognition, we develop a novel feature extraction method for vehicle classification. These three common classification algorithms are the k-nearest neighbor, the support vector machine, and the back-propagation neural network. Nevertheless, a problem remains with the original vehicle magnetic dataset collected being imbalanced, and may lead to inaccurate classification results. With this in mind, we propose an approach called SMOTE, which can further boost the performance of classifiers. Experimental results show that the k-nearest neighbor (KNN) classifier with the SMOTE algorithm can reach a classification accuracy of 95.46%, thus minimizing the effect of the imbalance.

Vehicle tracking for an evasive manoeuvres assistant using low-cost ultrasonic sensors.

Science.gov (United States)

Jiménez, Felipe; Naranjo, José E; Gómez, Oscar; Anaya, José J

2014-11-28

Many driver assistance systems require knowledge of the vehicle environment. As these systems are increasing in complexity and performance, this knowledge of the environment needs to be more complete and reliable, so sensor fusion combining long, medium and short range sensors is now being used. This paper analyzes the feasibility of using ultrasonic sensors for low cost vehicle-positioning and tracking in the lane adjacent to the host vehicle in order to identify free areas around the vehicle and provide information to an automatic avoidance collision system that can perform autonomous braking and lane change manoeuvres. A laser scanner is used for the early detection of obstacles in the direction of travel while two ultrasonic sensors monitor the blind spot of the host vehicle. The results of tests on a test track demonstrate the ability of these sensors to accurately determine the kinematic variables of the obstacles encountered, despite a clear limitation in range.

Vehicle Tracking for an Evasive Manoeuvres Assistant Using Low-Cost Ultrasonic Sensors

Directory of Open Access Journals (Sweden)

Felipe Jiménez

2014-11-01

Full Text Available Many driver assistance systems require knowledge of the vehicle environment. As these systems are increasing in complexity and performance, this knowledge of the environment needs to be more complete and reliable, so sensor fusion combining long, medium and short range sensors is now being used. This paper analyzes the feasibility of using ultrasonic sensors for low cost vehicle-positioning and tracking in the lane adjacent to the host vehicle in order to identify free areas around the vehicle and provide information to an automatic avoidance collision system that can perform autonomous braking and lane change manoeuvres. A laser scanner is used for the early detection of obstacles in the direction of travel while two ultrasonic sensors monitor the blind spot of the host vehicle. The results of tests on a test track demonstrate the ability of these sensors to accurately determine the kinematic variables of the obstacles encountered, despite a clear limitation in range.

Vehicle Lightweighting: Mass Reduction Spectrum Analysis and Process Cost Modeling

Energy Technology Data Exchange (ETDEWEB)

Mascarin, Anthony [IBIS Associates, Inc., Waltham, MA (United States); Hannibal, Ted [IBIS Associates, Inc., Waltham, MA (United States); Raghunathan, Anand [Energetics Inc., Columbia, MD (United States); Ivanic, Ziga [Energetics Inc., Columbia, MD (United States); Clark, Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-03-01

The U.S. Department of Energy’s Vehicle Technologies Office, Materials area commissioned a study to model and assess manufacturing economics of alternative design and production strategies for a series of lightweight vehicle concepts. In the first two phases of this effort examined combinations of strategies aimed at achieving strategic targets of 40% and a 45% mass reduction relative to a standard North American midsize passenger sedan at an effective cost of $3.42 per pound (lb) saved. These results have been reported in the Idaho National Laboratory report INL/EXT-14-33863 entitled Vehicle Lightweighting: 40% and 45% Weight Savings Analysis: Technical Cost Modeling for Vehicle Lightweighting published in March 2015. The data for these strategies were drawn from many sources, including Lotus Engineering Limited and FEV, Inc. lightweighting studies, U.S. Department of Energy-funded Vehma International of America, Inc./Ford Motor Company Multi-Material Lightweight Prototype Vehicle Demonstration Project, the Aluminum Association Transportation Group, many United States Council for Automotive Research’s/United States Automotive Materials Partnership LLC lightweight materials programs, and IBIS Associates, Inc.’s decades of experience in automotive lightweighting and materials substitution analyses.

Vehicle Lightweighting: Mass Reduction Spectrum Analysis and Process Cost Modeling

International Nuclear Information System (INIS)

Mascarin, Anthony; Hannibal, Ted; Raghunathan, Anand; Ivanic, Ziga; Clark, Michael

2016-01-01

The U.S. Department of Energy's Vehicle Technologies Office, Materials area commissioned a study to model and assess manufacturing economics of alternative design and production strategies for a series of lightweight vehicle concepts. In the first two phases of this effort examined combinations of strategies aimed at achieving strategic targets of 40% and a 45% mass reduction relative to a standard North American midsize passenger sedan at an effective cost of $3.42 per pound (lb) saved. These results have been reported in the Idaho National Laboratory report INL/EXT-14-33863 entitled Vehicle Lightweighting: 40% and 45% Weight Savings Analysis: Technical Cost Modeling for Vehicle Lightweighting published in March 2015. The data for these strategies were drawn from many sources, including Lotus Engineering Limited and FEV, Inc. lightweighting studies, U.S. Department of Energy-funded Vehma International of America, Inc./Ford Motor Company Multi-Material Lightweight Prototype Vehicle Demonstration Project, the Aluminum Association Transportation Group, many United States Council for Automotive Research's/United States Automotive Materials Partnership LLC lightweight materials programs, and IBIS Associates, Inc.'s decades of experience in automotive lightweighting and materials substitution analyses.

Optimizing plug-in electric vehicle charging in interaction with a small office building

Energy Technology Data Exchange (ETDEWEB)

Momber, Ilan; Gomez, Tomas [Instituto de Investigacion Tecnologica (IIT), Madrid (Spain); Dallinger, David; Beer, Sebastian; Wietschel, Martin [Fraunhofer Institute for Systems and Innovation Research, Karlsruhe (Germany). Competence Center Energy Policy and Energy Systems; Marnay, Chris; Stadler, Michael [Lawrence Berkeley Lab., CA (United States)

2011-07-01

This paper considers the integration of plug-in electric vehicles (PEVs) in micro-grids. Extending a theoretical framework for mobile storage connection, the economic analysis here turns to the interactions of commuters and their driving behavior with office buildings. An illustrative example for a real office building is reported. The chosen system includes solar thermal, photovoltaic, combined heat and power generation as well as an array of plug-in electric vehicles with a combined aggregated capacity of 864 kWh. With the benefit-sharing mechanism proposed here and idealized circumstances, estimated cost savings of 5% are possible. Different pricing schemes were applied which include flat rates, demand charges, as well as hourly variable final customer tariffs and their effects on the operation of intermittent storage were revealed and examined in detail. Because the plug-in electric vehicle connection coincides with peak heat and electricity loads as well as solar radiation, it is possible to shift energy demand as desired in order to realize cost savings. (orig.)

A telescopic cinema sound camera for observing high altitude aerospace vehicles

Science.gov (United States)

Slater, Dan

2014-09-01

Rockets and other high altitude aerospace vehicles produce interesting visual and aural phenomena that can be remotely observed from long distances. This paper describes a compact, passive and covert remote sensing system that can produce high resolution sound movies at >100 km viewing distances. The telescopic high resolution camera is capable of resolving and quantifying space launch vehicle dynamics including plume formation, staging events and payload fairing jettison. Flight vehicles produce sounds and vibrations that modulate the local electromagnetic environment. These audio frequency modulations can be remotely sensed by passive optical and radio wave detectors. Acousto-optic sensing methods were primarily used but an experimental radioacoustic sensor using passive micro-Doppler radar techniques was also tested. The synchronized combination of high resolution flight vehicle imagery with the associated vehicle sounds produces a cinema like experience that that is useful in both an aerospace engineering and a Hollywood film production context. Examples of visual, aural and radar observations of the first SpaceX Falcon 9 v1.1 rocket launch are shown and discussed.

Vehicle speed control using road bumps

Directory of Open Access Journals (Sweden)

T. A. O. Salau

2004-06-01

Full Text Available Road bumps play a crucial role in enforcing speed limits, thereby preventing overspeeding of vehicles. It significantly contributes to the overall road safety objective through the prevention of accidents that lead to deaths of pedestrians and damage of vehicles. Despite the importance of road bumps, very little research has been done to investigate into their design. While documentation exists on quantitative descriptions of road bumps, they offer little guidance to decision making. This work presents a unique approach to solving road bumps design problems. The results of our study reveal three important road bumps variables that influence the control of vehicle speeds. The key variables are bump height, bump width, and effective distance between two consecutive road bumps. Since vehicle speed control is the ultimate aim of this study the relationship between vehicle speed and other variables earlier mentioned is established. Vehicle speed is defined as the product of frequency at which a vehicle is moving over road bumps and the sum of effective distance between two consecutive road bumps. In the determination of bump height we assume a conical shaped curve for analysis as a matter of research strategy. Based on this, two stages of motion were analysed. The first concerns the motion over the bump itself while the second relates to the motion between two consecutive road bumps. Fourier series was then used to formulate a holistic equation that combines these two stages. We used trigonometric functions to model the behaviour of the first stage while with the second stage giving a functional value of zero since no changes in height are observed. We carried out vibration analysis to determine the effect of road bumps on a vehicular system. Arising from this a model component is referred to as an isolation factor. This offers guidance to the safe frequency at which vehicles could travel over road bumps. The work appears to contribute to knowledge

Hardware-in-loop simulation of electric vehicles automated mechanical transmission system

Energy Technology Data Exchange (ETDEWEB)

Liao, C.; Wu, Y.; Wang, L. [Chinese Academy of Sciences, Beijing (China). Inst. of Electrical Engineering

2009-03-11

Automated mechanical transmission (AMT) can be used to enhance the performance of hybrid electric vehicles. In this study, hardware-in-loop (HIL) simulations were used to develop an AMT control system. HIL was used to simulate the running and fault status of the system as well as to optimize its performance. HIL was combined with a commercial simulation tool and an automatic code generation technology in a real time environment tool to develop the AMT control system. A hybrid vehicle system dynamics model was generated and then simulated in various real time operating vehicle environments. Virtual instrument technology was used to develop real time monitoring, parameter matching calibration, data acquisition and offline analyses for the optimization of the control system. Results of the analyses demonstrated that the AMT control system can be used to optimize the performance of hybrid electric vehicles. 5 refs., 9 figs.

Marine Vehicle Sensor Network Architecture and Protocol Designs for Ocean Observation

Directory of Open Access Journals (Sweden)

Yeqiang Shu

2012-01-01

Full Text Available The micro-scale and meso-scale ocean dynamic processes which are nonlinear and have large variability, have a significant impact on the fisheries, natural resources, and marine climatology. A rapid, refined and sophisticated observation system is therefore needed in marine scientific research. The maneuverability and controllability of mobile sensor platforms make them a preferred choice to establish ocean observing networks, compared to the static sensor observing platform. In this study, marine vehicles are utilized as the nodes of mobile sensor networks for coverage sampling of a regional ocean area and ocean feature tracking. A synoptic analysis about marine vehicle dynamic control, multi vehicles mission assignment and path planning methods, and ocean feature tracking and observing techniques is given. Combined with the observation plan in the South China Sea, we provide an overview of the mobile sensor networks established with marine vehicles, and the corresponding simulation results.

Connected vehicle application : safety.

Science.gov (United States)

2015-01-01

Connected vehicle safety applications are designed to increase situational awareness : and reduce or eliminate crashes through vehicle-to-infrastructure (V2I), vehicle-to-vehicle (V2V), and vehicle-to-pedestrian (V2P) data transmissions. Applications...

Vehicle to grid: electric vehicles as an energy storage solution

Science.gov (United States)

McGee, Rodney; Waite, Nicholas; Wells, Nicole; Kiamilev, Fouad E.; Kempton, Willett M.

2013-05-01

With increased focus on intermittent renewable energy sources such as wind turbines and photovoltaics, there comes a rising need for large-scale energy storage. The vehicle to grid (V2G) project seeks to meet this need using electric vehicles, whose high power capacity and existing power electronics make them a promising energy storage solution. This paper will describe a charging system designed by the V2G team that facilitates selective charging and backfeeding by electric vehicles. The system consists of a custom circuit board attached to an embedded linux computer that is installed both in the EVSE (electric vehicle supply equipment) and in the power electronics unit of the vehicle. The boards establish an in-band communication link between the EVSE and the vehicle, giving the vehicle internet connectivity and the ability to make intelligent decisions about when to charge and discharge. This is done while maintaining compliance with existing charging protocols (SAEJ1772, IEC62196) and compatibility with standard "nonintelligent" cars and chargers. Through this system, the vehicles in a test fleet have been able to successfully serve as portable temporary grid storage, which has implications for regulating the electrical grid, providing emergency power, or supplying power to forward military bases.

RFID-based vehicle positioning and its applications in connected vehicles.

Science.gov (United States)

Wang, Jianqiang; Ni, Daiheng; Li, Keqiang

2014-03-04

This paper proposed an RFID-based vehicle positioning approach to facilitate connected vehicles applications. When a vehicle passes over an RFID tag, the vehicle position is given by the accurate position stored in the tag. At locations without RFID coverage, the vehicle position is estimated from the most recent tag location using a kinematics integration algorithm till updates from the next tag. The accuracy of RFID positioning is verified empirically in two independent ways with one using radar and the other a photoelectric switch. The former is designed to verify whether the dynamic position obtained from RFID tags matches the position measured by radar that is regarded as accurate. The latter aims to verify whether the position estimated from the kinematics integration matches the position obtained from RFID tags. Both means supports the accuracy of RFID-based positioning. As a supplement to GPS which suffers from issues such as inaccuracy and loss of signal, RFID positioning is promising in facilitating connected vehicles applications. Two conceptual applications are provided here with one in vehicle operational control and the other in Level IV intersection control.

Strategy and Evaluation of Vehicle Collision Avoidance Control via Hardware-in-the-Loop Platform

Directory of Open Access Journals (Sweden)

Sin-Li Chen

2016-11-01

Full Text Available This paper proposes a novel control approach for vehicle collision avoidance of urban vehicles. For safe driving in urban environments, this paper presents both one-dimensional and two-dimensional solutions, which can be applied to the collision avoidance via steering assistance, automatic braking, and warning of collision. Strategies are verified under the software CarSim, and the experimental evaluations are carried out under the combination of CarSim with a hardware-in-the-loop platform. The results show the feasibility and effectiveness of the proposed algorithm on vehicle collision avoidance.

Experimental investigation of a quad-rotor biplane micro air vehicle

Science.gov (United States)

Bogdanowicz, Christopher Michael

Micro air vehicles are expected to perform demanding missions requiring efficient operation in both hover and forward flight. This thesis discusses the development of a hybrid air vehicle which seamlessly combines both flight capabilities: hover and high-speed forward flight. It is the quad-rotor biplane, which weighs 240 grams and consists of four propellers with wings arranged in a biplane configuration. The performance of the vehicle system was investigated in conditions representative of flight through a series of wind tunnel experiments. These studies provided an understanding of propeller-wing interaction effects and system trim analysis. This showed that the maximum speed of 11 m/s and a cruise speed of 4 m/s were achievable and that the cruise power is approximately one-third of the hover power. Free flight testing of the vehicle successfully highlighted its ability to achieve equilibrium transition flight. Key design parameters were experimentally investigated to understand their effect on overall performance. It was found that a trade-off between efficiency and compactness affects the final choice of the design. Design improvements have allowed for decreases in vehicle weight and ground footprint, while increasing structural soundness. Numerous vehicle designs, models, and flight tests have proven system scalability as well as versatility, including an upscaled model to be utilized in an extensive commercial package delivery system. Overall, the quad-rotor biplane is proven to be an efficient and effective multi-role vehicle.

Vehicle-network defensive aids suite

Science.gov (United States)

Rapanotti, John

2005-05-01

Defensive Aids Suites (DAS) developed for vehicles can be extended to the vehicle network level. The vehicle network, typically comprising four platoon vehicles, will benefit from improved communications and automation based on low latency response to threats from a flexible, dynamic, self-healing network environment. Improved DAS performance and reliability relies on four complementary sensor technologies including: acoustics, visible and infrared optics, laser detection and radar. Long-range passive threat detection and avoidance is based on dual-purpose optics, primarily designed for manoeuvring, targeting and surveillance, combined with dazzling, obscuration and countermanoeuvres. Short-range active armour is based on search and track radar and intercepting grenades to defeat the threat. Acoustic threat detection increases the overall robustness of the DAS and extends the detection range to include small calibers. Finally, detection of active targeting systems is carried out with laser and radar warning receivers. Synthetic scene generation will provide the integrated environment needed to investigate, develop and validate these new capabilities. Computer generated imagery, based on validated models and an acceptable set of benchmark vignettes, can be used to investigate and develop fieldable sensors driven by real-time algorithms and countermeasure strategies. The synthetic scene environment will be suitable for sensor and countermeasure development in hardware-in-the-loop simulation. The research effort focuses on two key technical areas: a) computing aspects of the synthetic scene generation and b) and development of adapted models and databases. OneSAF is being developed for research and development, in addition to the original requirement of Simulation and Modelling for Acquisition, Rehearsal, Requirements and Training (SMARRT), and is becoming useful as a means for transferring technology to other users, researchers and contractors. This procedure

Cooperative Intelligence in Roundabout Intersections Using Hierarchical Fuzzy Behavior Calculation of Vehicle Speed Profile

Directory of Open Access Journals (Sweden)

Bosankić Ivan

2016-01-01

Full Text Available In this paper, a new fuzzy-behavior-based algorithm for roundabout intersection management is presented. The algorithm employs cooperative intelligence and includes intelligent vehicles and infrastructure to calculate speed profiles for different vehicles, in order to achieve more comfortable driving profiles, as well to reduce congestion and CO2 emissions. The algorithm uses adaptive spatio-temporal reservation technique and was tested in MATLAB/Simulink environment. The algorithm is designed to function in different scenarios with both cooperative and non-cooperative vehicles, as well as optional intersection infrastructure. Results have show that using the proposed algorithm different vehicle communication types can be successfully combined in order to increase traffic flow through roundabout intersections.

Determining optimum flash patterns for emergency service vehicles: an experimental investigation using high definition film.

Science.gov (United States)

Turner, Sally; Wylde, Julie; Langham, Martin; Morrow, Andrew

2014-09-01

An investigation of how emergency vehicle lighting (EVL) can be improved is reported with reference to an analysis of police vehicle road traffic accidents (Study 1). In Study 2, 37 regular drivers were shown film clips of a marked police vehicle, in which flash rate (1 Hz, 4 Hz) and pattern (single, triple pulse) were varied on the blue Light Emitting Diode (LED) roofbar. Results indicate a 4 Hz flash rate conveys greater urgency than a 1 Hz rate, while a 1 Hz, single flash combination was ranked the least urgent of all combinations. Participants claimed they would leave significantly more space before pulling out in front of an approaching police car (gap acceptance) in the 4 Hz single pulse condition in comparison to other EVL combinations. The preliminary implications for which flash characteristics could prove most optimal for emergency service use are discussed with regard to effects on driver perception and expected driving behaviour. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Broadband vehicle-to-vehicle communication using an extended autonomous cruise control sensor

Science.gov (United States)

Heddebaut, M.; Rioult, J.; Ghys, J. P.; Gransart, Ch; Ambellouis, S.

2005-06-01

For several years road vehicle autonomous cruise control (ACC) systems as well as anti-collision radar have been developed. Several manufacturers currently sell this equipment. The current generation of ACC sensors only track the first preceding vehicle to deduce its speed and position. These data are then used to compute, manage and optimize a safety distance between vehicles, thus providing some assistance to car drivers. However, in real conditions, to elaborate and update a real time driving solution, car drivers use information about speed and position of preceding and following vehicles. This information is essentially perceived using the driver's eyes, binocular stereoscopic vision performed through the windscreens and rear-view mirrors. Furthermore, within a line of vehicles, the frontal road perception of the first vehicle is very particular and highly significant. Currently, all these available data remain strictly on-board the vehicle that has captured the perception information and performed these measurements. To get the maximum effectiveness of all these approaches, we propose that this information be shared in real time with the following vehicles, within the convoy. On the basis of these considerations, this paper technically explores a cost-effective solution to extend the basic ACC sensor function in order to simultaneously provide a vehicle-to-vehicle radio link. This millimetre wave radio link transmits relevant broadband perception data (video, localization...) to following vehicles, along the line of vehicles. The propagation path between the vehicles uses essentially grazing angles of incidence of signals over the road surface including millimetre wave paths beneath the cars.

Drivers of Vaginal Drug Delivery System Acceptability from Internet-Based Conjoint Analysis.

Directory of Open Access Journals (Sweden)

Rachel J Primrose

Full Text Available Vaginal microbicides potentially empower women to protect themselves from HIV and other sexually transmitted infections (STIs, especially when culture, religion, or social status may prevent them from negotiating condom use. The open literature contains minimal information on factors that drive user acceptability of women's health products or vaginal drug delivery systems. By understanding what women find to be most important with regard to sensory properties and product functionality, developers can iteratively formulate a more desirable product. Conjoint analysis is a technique widely used in market research to determine what combination of elements influence a consumer's willingness to try or use a product. We applied conjoint analysis here to better understand what sexually-active woman want in a microbicide, toward our goal of formulating a product that is highly acceptable to women. Both sensory and non-sensory attributes were tested, including shape, color, wait time, partner awareness, messiness/leakage, duration of protection, and functionality. Heterosexually active women between 18 and 35 years of age in the United States (n = 302 completed an anonymous online conjoint survey using IdeaMap software. Attributes (product elements were systematically presented in various combinations; women rated these combinations of a 9-point willingness-to-try scale. By coupling systematic combinations and regression modeling, we can estimate the unique appeal of each element. In this population, a multifunctional product (i.e., broad spectrum STI protection, coupled with conception is far more desirable than a microbicide targeted solely for HIV protection; we also found partner awareness and leakage are potentially strong barriers to use.

Drivers of Vaginal Drug Delivery System Acceptability from Internet-Based Conjoint Analysis.

Science.gov (United States)

Primrose, Rachel J; Zaveri, Toral; Bakke, Alyssa J; Ziegler, Gregory R; Moskowitz, Howard R; Hayes, John E

2016-01-01

Vaginal microbicides potentially empower women to protect themselves from HIV and other sexually transmitted infections (STIs), especially when culture, religion, or social status may prevent them from negotiating condom use. The open literature contains minimal information on factors that drive user acceptability of women's health products or vaginal drug delivery systems. By understanding what women find to be most important with regard to sensory properties and product functionality, developers can iteratively formulate a more desirable product. Conjoint analysis is a technique widely used in market research to determine what combination of elements influence a consumer's willingness to try or use a product. We applied conjoint analysis here to better understand what sexually-active woman want in a microbicide, toward our goal of formulating a product that is highly acceptable to women. Both sensory and non-sensory attributes were tested, including shape, color, wait time, partner awareness, messiness/leakage, duration of protection, and functionality. Heterosexually active women between 18 and 35 years of age in the United States (n = 302) completed an anonymous online conjoint survey using IdeaMap software. Attributes (product elements) were systematically presented in various combinations; women rated these combinations of a 9-point willingness-to-try scale. By coupling systematic combinations and regression modeling, we can estimate the unique appeal of each element. In this population, a multifunctional product (i.e., broad spectrum STI protection, coupled with conception) is far more desirable than a microbicide targeted solely for HIV protection; we also found partner awareness and leakage are potentially strong barriers to use.

Optimal Solubility of Diclofenac β-Cyclodextrin in Combination with Local Anaesthetics for Mesotherapy Applications.

Science.gov (United States)

Tringali, Giuseppe; Navarra, Pierluigi

2017-01-01

Because of low injection volume, the recently marketed injectable solution of diclofenac in complex with β -cyclodextrin (Akis®, IBSA Farmaceutici Italia) is an ideal candidate for mesotherapy applications. In this study, we investigated the solubility of Akis, 25 and 50 mg/kg, in combination with various local anaesthetics (lidocaine, mepivacaine, bupivacaine, levobupivacaine, and ropivacaine) at different concentrations in aqueous vehicles (normal saline, sterile water, or bicarbonate). Final injection mixtures were classified as limpid, turbid, or milky at visual analysis under standardized conditions. We found that (i) the use of sterile water for injections or normal saline as vehicles to dilute Akis in combination with whatever local anaesthetic normally results in milky solutions and therefore is not recommended; (ii) using bicarbonate, optimal solubility was obtained combining Akis with lidocaine, both 1 and 2%, or mepivacaine, both 1 and 2%, whereas solutions were turbid in combination with bupivacaine, levobupivacaine, or ropivacaine. Thus, we recommend that Akis is used in combination with lidocaine or mepivacaine in a bicarbonate vehicle.

Optimal Solubility of Diclofenac β-Cyclodextrin in Combination with Local Anaesthetics for Mesotherapy Applications

Directory of Open Access Journals (Sweden)

Giuseppe Tringali

2017-01-01

Full Text Available Because of low injection volume, the recently marketed injectable solution of diclofenac in complex with β-cyclodextrin (Akis®, IBSA Farmaceutici Italia is an ideal candidate for mesotherapy applications. In this study, we investigated the solubility of Akis, 25 and 50 mg/kg, in combination with various local anaesthetics (lidocaine, mepivacaine, bupivacaine, levobupivacaine, and ropivacaine at different concentrations in aqueous vehicles (normal saline, sterile water, or bicarbonate. Final injection mixtures were classified as limpid, turbid, or milky at visual analysis under standardized conditions. We found that (i the use of sterile water for injections or normal saline as vehicles to dilute Akis in combination with whatever local anaesthetic normally results in milky solutions and therefore is not recommended; (ii using bicarbonate, optimal solubility was obtained combining Akis with lidocaine, both 1 and 2%, or mepivacaine, both 1 and 2%, whereas solutions were turbid in combination with bupivacaine, levobupivacaine, or ropivacaine. Thus, we recommend that Akis is used in combination with lidocaine or mepivacaine in a bicarbonate vehicle.

Affordable Flight Demonstration of the GTX Air-Breathing SSTO Vehicle Concept

Science.gov (United States)

Krivanek, Thomas M.; Roche, Joseph M.; Riehl, John P.; Kosareo, Daniel N.

2003-01-01

The rocket based combined cycle (RBCC) powered single-stage-to-orbit (SSTO) reusable launch vehicle has the potential to significantly reduce the total cost per pound for orbital payload missions. To validate overall system performance, a flight demonstration must be performed. This paper presents an overview of the first phase of a flight demonstration program for the GTX SSTO vehicle concept. Phase 1 will validate the propulsion performance of the vehicle configuration over the supersonic and hypersonic air- breathing portions of the trajectory. The focus and goal of Phase 1 is to demonstrate the integration and performance of the propulsion system flowpath with the vehicle aerodynamics over the air-breathing trajectory. This demonstrator vehicle will have dual mode ramjetkcramjets, which include the inlet, combustor, and nozzle with geometrically scaled aerodynamic surface outer mold lines (OML) defining the forebody, boundary layer diverter, wings, and tail. The primary objective of this study is to demon- strate propulsion system performance and operability including the ram to scram transition, as well as to validate vehicle aerodynamics and propulsion airframe integration. To minimize overall risk and develop ment cost the effort will incorporate proven materials, use existing turbomachinery in the propellant delivery systems, launch from an existing unmanned remote launch facility, and use basic vehicle recovery techniques to minimize control and landing requirements. A second phase would demonstrate propulsion performance across all critical portions of a space launch trajectory (lift off through transition to all-rocket) integrated with flight-like vehicle systems.

Deriving vehicle-to-grid business models from consumer preferences

NARCIS (Netherlands)

Bohnsack, René; van den Hoed, Robert; Oude Reimer, Hugo

2015-01-01

Combining electric cars with utility services seems to be a natural fit and holds the promise to tackle various mobility as well as electricity challenges at the same time. So far no viable business model for vehicle-to-grid technology has emerged, raising the question which characteristics a

Vehicle underbody fairing

Science.gov (United States)

Ortega, Jason M.; Salari, Kambiz; McCallen, Rose

2010-11-09

A vehicle underbody fairing apparatus for reducing aerodynamic drag caused by a vehicle wheel assembly, by reducing the size of a recirculation zone formed under the vehicle body immediately downstream of the vehicle wheel assembly. The fairing body has a tapered aerodynamic surface that extends from a front end to a rear end of the fairing body with a substantially U-shaped cross-section that tapers in both height and width. Fasteners or other mounting devices secure the fairing body to an underside surface of the vehicle body, so that the front end is immediately downstream of the vehicle wheel assembly and a bottom section of the tapered aerodynamic surface rises towards the underside surface as it extends in a downstream direction.

"Can Vehicle-to-Grid Revenue Help Electric Vehicles on the Market?"

OpenAIRE

George R. Parsons; Michael K. Hidrue; Willett Kempton; Meryl P. Gardner

2011-01-01

Vehicle-to-grid (V2G) electric vehicles can return power stored in their batteries back to the power grid and be programmed to do so at times when power prices are high. Since providing this service can lead to payments to owners of vehicles, it effectively reduces the cost of electric vehicles. Using data from a national stated preference survey (n = 3029), this paper presents the first study of the potential consumer demand for V2G electric vehicles. In our choice experiment, 3029 responden...

Distributed Road Grade Estimation for Heavy Duty Vehicles

Energy Technology Data Exchange (ETDEWEB)

Sahlholm, Per

2011-07-01

torque are combined with observations of the road altitude from a GPS receiver, using vehicle and road models. The operation of the estimators is adjusted during gearshifts, braking, and poor satellite coverage, to account for variations in sensor and model reliability. The estimated error covariances of the road grade estimates are used together with their absolute positions to update a stored road grade map. Highway driving trials show that the proposed estimators produce accurate road grade data. The estimation performance improves as the number of road segment traces increases. A vehicle equipped with the proposed system will rapidly develop a road grade map for its area of operation. Simulations show that collaborative generation of the third dimension for a pre-existing large area two-dimensional map is feasible. The experimental results indicate that road grade estimates from the proposed methods are accurate enough to be used in predictive vehicle control systems to enhance safety, efficiency, and driver comfort in heavy duty vehicles. The grade estimators may also be used for on-line validation of road grade information from other sources. This is important in on-board applications, since the envisioned control applications can degrade vehicle performance if inaccurate data are used

Combining MHD Airbreathing and Fusion Rocket Propulsion for Earth-to-Orbit Flight

International Nuclear Information System (INIS)

Froning, H. D. Jr; Yang, Yang; Momota, H.; Burton, E.; Miley, G. H.; Luo, Nie

2005-01-01

Previous studies have shown that Single-State-to-Orbit (SSTO) vehicle propellant can be reduced by Magnets-Hydro-Dynamic (MHD) processes that minimize airbreathing propulsion losses and propellant consumption during atmospheric flight. Similarly additional reduction in SSTO propellant is enabled by Inertial Electrostatic Confinement (IEC) fusion, whose more energetic reactions reduce rocket propellant needs. MHD airbreathing propulsion during an SSTO vehicle's initial atmospheric flight phase and IEC fusion propulsion during its final exo-atmospheric flight phase is therefore being explored. Accomplished work is not yet sufficient for claiming such a vehicle's feasibility. But takeoff and propellant mass for an MHD airbreathing and IEC fusion vehicle could be as much as 25 and 40 percent less than one with ordinary airbreathing and IEC fusion; and as much as 50 and 70 percent less than SSTO takeoff and propellant mass with MHD airbreathing and chemical rocket propulsion. Thus this unusual combined cycle engine shows great promise for performance gains beyond contemporary combined-cycle airbreathing engines

Vehicle technologies, fuel-economy policies, and fuel-consumption rates of Chinese vehicles

International Nuclear Information System (INIS)

Huo Hong; He Kebin; Wang, Michael; Yao Zhiliang

2012-01-01

One of the principal ways to reduce transport-related energy use is to reduce fuel-consumption rates of motor vehicles (usually measured in liters of fuel per 100 km). Since 2004, China has implemented policies to improve vehicle technologies and lower the fuel-consumption rates of individual vehicles. Policy evaluation requires accurate and adequate information on vehicle fuel-consumption rates. However, such information, especially for Chinese vehicles under real-world operating conditions, is rarely available from official sources in China. For each vehicle type we first review the vehicle technologies and fuel-economy policies currently in place in China and their impacts. We then derive real-world (or on-road) fuel-consumption rates on the basis of information collected from various sources. We estimate that the real-world fuel-consumption rates of vehicles in China sold in 2009 are 9 L/100 km for light-duty passenger vehicles, 11.4 L/100 km for light-duty trucks, 22 L/100 km for inter-city transport buses, 40 L/100 km for urban transit buses, and 24.9 L/100 km for heavy-duty trucks. These results aid in understanding the levels of fuel consumption of existing Chinese vehicle fleets and the effectiveness of policies in reducing on-road fuel consumption, which can help in designing and evaluating future vehicle energy-efficiency policies. - Highlights: ► Vehicle fuel-consumption rate (VFCR) data are rarely available in China. ► We review the fuel-economy policies currently in place in China and their impacts. ► We derive real-world VFCRs on the basis of information collected from various sources. ► Results aid in understanding the fuel consumption levels of Chinese vehicle fleets. ► Results help in designing and evaluating future vehicle energy-efficiency policies.

Full-Scale Passive Earth Entry Vehicle Landing Tests: Methods and Measurements

Science.gov (United States)

Littell, Justin D.; Kellas, Sotiris

2018-01-01

During the summer of 2016, a series of drop tests were conducted on two passive earth entry vehicle (EEV) test articles at the Utah Test and Training Range (UTTR). The tests were conducted to evaluate the structural integrity of a realistic EEV vehicle under anticipated landing loads. The test vehicles were lifted to an altitude of approximately 400m via a helicopter and released via release hook into a predesignated 61 m landing zone. Onboard accelerometers were capable of measuring vehicle free flight and impact loads. High-speed cameras on the ground tracked the free-falling vehicles and data was used to calculate critical impact parameters during the final seconds of flight. Additional sets of high definition and ultra-high definition cameras were able to supplement the high-speed data by capturing the release and free flight of the test articles. Three tests were successfully completed and showed that the passive vehicle design was able to withstand the impact loads from nominal and off-nominal impacts at landing velocities of approximately 29 m/s. Two out of three test resulted in off-nominal impacts due to a combination of high winds at altitude and the method used to suspend the vehicle from the helicopter. Both the video and acceleration data captured is examined and discussed. Finally, recommendations for improved release and instrumentation methods are presented.

An Integrated Model of Motion, Steering, Positioning and Stabilization of an Unmanned Autonomous Maritime Vehicle

Directory of Open Access Journals (Sweden)

Miroslaw Gerigk

2015-12-01

Full Text Available In the paper the aim of an interdisciplinary research is presented. The research method is introduced. An object the unmanned autonomous maritime vehicle is briefly described. The key research problem concerns a combined model of the vehicle motion including the loads of lift and hydrodynamic nature. The model takes into account the gravity and displacement forces, resistance and thrust forces, lift and other hydrodynamic forces. One of the major research tasks is to precisely predict the position of the vehicle. To do that an integrated model of acquiring, analyzing and processing the signals is necessary. The processed signals may then be used for the precise steering of the vehicle. The vehicle should be equipped with a stabilization system. Some information on an integrated steering, positioning and stabilization system of the vehicle is briefly presented in the paper. Such the system enables to obtain a fully autonomous vehicle. Some information on the propulsion and underwater energy supply systems are presented in the paper, too.

Investigating methods for determining mismatch in near side vehicle impacts - biomed 2009.

Science.gov (United States)

Loftis, Kathryn; Martin, R Shayn; Meredith, J Wayne; Stitzel, Joel

2009-01-01

This study investigates vehicle mismatch in severe side-impact motor vehicle collisions. Research conducted by the Insurance Institute for Highway Safety has determined that vehicle mismatch often leads to very severe injuries for occupants in the struck vehicle, because the larger striking vehicle does not engage the lower sill upon impact, resulting in severe intrusions into the occupant compartment. Previous studies have analyzed mismatched collisions according to vehicle type, not by the difference in vehicle height and weight. It is hypothesized that the combination of a heavier striking vehicle at a taller height results in more intrusion for the struck vehicle and severe injury for the near side occupant. By analyzing Crash Injury Research and Engineering Network (CIREN) data and occupant injury severity, it is possible to study intrusion and injuries that occur due to vehicle mismatch. CIREN enrolls seriously injured occupants involved in motor vehicle crashes (MVC) across the United States. From the Toyota-Wake Forest University CIREN center, 23 near side impact cases involving two vehicles were recorded. Only 3 of these seriously injured occupant cases were not considered mismatched according to vehicle curb weight, and only 2 were not considered vehicle mismatched according to height differences. The mismatched CIREN cases had an average difference in vehicle curb weight of 737.0 kg (standard deviation of 646.8) and an average difference in vehicle height of 16.38 cm (standard deviation of 7.186). There were 13 occupants with rib fractures, 12 occupants with pelvic fractures, 9 occupants with pulmonary contusion, and 5 occupants with head injuries, among other multiple injuries. The average Injury Severity Score (ISS) for these occupants was 27, with a standard deviation of 16. The most serious injuries resulted in an Abbreviated Injury Scale (AIS) of 5, which included 3 occupants. Each of these AIS 5 injuries were to different body regions on different

A hybrid GA-TS algorithm for open vehicle routing optimization of coal mines material

Energy Technology Data Exchange (ETDEWEB)

Yu, S.W.; Ding, C.; Zhu, K.J. [China University of Geoscience, Wuhan (China)

2011-08-15

In the open vehicle routing problem (OVRP), the objective is to minimize the number of vehicles and the total distance (or time) traveled. This study primarily focuses on solving an open vehicle routing problem (OVRP) by applying a novel hybrid genetic algorithm and the Tabu search (GA-TS), which combines the GA's parallel computing and global optimization with TS's Tabu search skill and fast local search. Firstly, the proposed algorithm uses natural number coding according to the customer demands and the captivity of the vehicle for globe optimization. Secondly, individuals of population do TS local search with a certain degree of probability, namely, do the local routing optimization of all customer sites belong to one vehicle. The mechanism not only improves the ability of global optimization, but also ensures the speed of operation. The algorithm was used in Zhengzhou Coal Mine and Power Supply Co., Ltd.'s transport vehicle routing optimization.

Simulation of electric vehicles with hybrid power systems

Science.gov (United States)

Burke, A. F.; Cole, G. H.

Computer programs for the simulation of the operation of electric vehicles with hybrid power systems are described. These programs treat cases in which high energy density ultracapacitors or high power density pulse batteries are used to load level the main energy storage battery in the vehicle. A generalized control strategy for splitting the power between the main battery and the pulse power devices is implemented such that the user can specify the nominal battery power as a function of the state-of-charge of the ultracapacitor or pulse power battery. The programs display graphically on the screen, as they run, the power from both the main battery and the pulse power device and the state-of-charge of the pulse power device. After each run is completed, a summary is printed out from which the effect of load leveling the battery on vehicle range and energy consumption can be determined. Default input files are provided with the programs so various combinations of vehicles, driveline components, and batteries of special current interest to the EV community can be run with either type of pulse power device. Typical simulation results are shown including cases in which the pulse power devices are connected in parallel with the main battery without interface electronics.

RFID-Based Vehicle Positioning and Its Applications in Connected Vehicles

Science.gov (United States)

Wang, Jianqiang; Ni, Daiheng; Li, Keqiang

2014-01-01

This paper proposed an RFID-based vehicle positioning approach to facilitate connected vehicles applications. When a vehicle passes over an RFID tag, the vehicle position is given by the accurate position stored in the tag. At locations without RFID coverage, the vehicle position is estimated from the most recent tag location using a kinematics integration algorithm till updates from the next tag. The accuracy of RFID positioning is verified empirically in two independent ways with one using radar and the other a photoelectric switch. The former is designed to verify whether the dynamic position obtained from RFID tags matches the position measured by radar that is regarded as accurate. The latter aims to verify whether the position estimated from the kinematics integration matches the position obtained from RFID tags. Both means supports the accuracy of RFID-based positioning. As a supplement to GPS which suffers from issues such as inaccuracy and loss of signal, RFID positioning is promising in facilitating connected vehicles applications. Two conceptual applications are provided here with one in vehicle operational control and the other in Level IV intersection control. PMID:24599188

RFID-Based Vehicle Positioning and Its Applications in Connected Vehicles

Directory of Open Access Journals (Sweden)

Jianqiang Wang

2014-03-01

Full Text Available This paper proposed an RFID-based vehicle positioning approach to facilitate connected vehicles applications. When a vehicle passes over an RFID tag, the vehicle position is given by the accurate position stored in the tag. At locations without RFID coverage, the vehicle position is estimated from the most recent tag location using a kinematics integration algorithm till updates from the next tag. The accuracy of RFID positioning is verified empirically in two independent ways with one using radar and the other a photoelectric switch. The former is designed to verify whether the dynamic position obtained from RFID tags matches the position measured by radar that is regarded as accurate. The latter aims to verify whether the position estimated from the kinematics integration matches the position obtained from RFID tags. Both means supports the accuracy of RFID-based positioning. As a supplement to GPS which suffers from issues such as inaccuracy and loss of signal, RFID positioning is promising in facilitating connected vehicles applications. Two conceptual applications are provided here with one in vehicle operational control and the other in Level IV intersection control.

Using conjoint analysis to measure the acceptability of rectal microbicides among men who have sex with men in four South American cities.

Science.gov (United States)

Kinsler, Janni J; Cunningham, William E; Nureña, César R; Nadjat-Haiem, Carsten; Grinsztejn, Beatriz; Casapia, Martin; Montoya-Herrera, Orlando; Sánchez, Jorge; Galea, Jerome T

2012-08-01

Conjoint Analysis (CJA), a statistical market-based technique that assesses the value consumers place on product characteristics, may be used to predict acceptability of hypothetical products. Rectal Microbicides (RM)-substances that would prevent HIV infection during receptive anal intercourse-will require acceptability data from potential users in multiple settings to inform the development process by providing valuable information on desirable product characteristics and issues surrounding potential barriers to product use. This study applied CJA to explore the acceptability of eight different hypothetical RM among 128 MSM in Lima and Iquitos, Peru; Guayaquil, Ecuador; and Rio de Janeiro, Brazil. Overall RM acceptability was highest in Guayaquil and lowest in Rio. Product effectiveness had the greatest impact on acceptability in all four cities, but the impact of other product characteristics varied by city. This study demonstrates that MSM from the same region but from different cities place different values on RM characteristics that could impact uptake of an actual RM. Understanding specific consumer preferences is crucial during RM product development, clinical trials and eventual product dissemination.

Space vehicle chassis

Science.gov (United States)

Judd, Stephen; Dallmann, Nicholas; Seitz, Daniel; Martinez, John; Storms, Steven; Kestell, Gayle

2017-07-18

A modular space vehicle chassis may facilitate convenient access to internal components of the space vehicle. Each module may be removable from the others such that each module may be worked on individually. Multiple panels of at least one of the modules may swing open or otherwise be removable, exposing large portions of the internal components of the space vehicle. Such chassis architectures may reduce the time required for and difficulty of performing maintenance or modifications, may allow multiple space vehicles to take advantage of a common chassis design, and may further allow for highly customizable space vehicles.

Research on motor braking-based DYC strategy for distributed electric vehicle

Science.gov (United States)

Zhang, Jingming; Liao, Weijie; Chen, Lei; Cui, Shumei

2017-08-01

In order to bring into full play the advantages of motor braking and enhance the handling stability of distributed electric vehicle, a motor braking-based direct yaw moment control (DYC) strategy was proposed. This strategy could identify whether a vehicle has under-steered or overs-steered, to calculate the direct yaw moment required for vehicle steering correction by taking the corrected yaw velocity deviation and slip-angle deviation as control variables, and exert motor braking moment on the target wheels to perform correction in the manner of differential braking. For validation of the results, a combined simulation platform was set up finally to simulate the motor braking control strategy proposed. As shown by the results, the motor braking-based DYC strategy timely adjusted the motor braking moment and hydraulic braking moment on the target wheels, and corrected the steering deviation and sideslip of the vehicle in unstable state, improving the handling stability.

Combing VFH with bezier for motion planning of an autonomous vehicle

Science.gov (United States)

Ye, Feng; Yang, Jing; Ma, Chao; Rong, Haijun

2017-08-01

Vector Field Histogram (VFH) is a method for mobile robot obstacle avoidance. However, due to the nonholonomic constraints of the vehicle, the algorithm is seldom applied to autonomous vehicles. Especially when we expect the vehicle to reach target location in a certain direction, the algorithm is often unsatisfactory. Fortunately, the Bezier Curve is defined by the states of the starting point and the target point. We can use this feature to make the vehicle in the expected direction. Therefore, we propose an algorithm to combine the Bezier Curve with the VFH algorithm, to search for the collision-free states with the VFH search method, and to select the optimal trajectory point with the Bezier Curve as the reference line. This means that we will improve the cost function in the VFH algorithm by comparing the distance between candidate directions and reference line. Finally, select the closest direction to the reference line to be the optimal motion direction.

Fuel economy and life-cycle cost analysis of a fuel cell hybrid vehicle

Science.gov (United States)

Jeong, Kwi Seong; Oh, Byeong Soo

The most promising vehicle engine that can overcome the problem of present internal combustion is the hydrogen fuel cell. Fuel cells are devices that change chemical energy directly into electrical energy without combustion. Pure fuel cell vehicles and fuel cell hybrid vehicles (i.e. a combination of fuel cell and battery) as energy sources are studied. Considerations of efficiency, fuel economy, and the characteristics of power output in hybridization of fuel cell vehicle are necessary. In the case of Federal Urban Driving Schedule (FUDS) cycle simulation, hybridization is more efficient than a pure fuel cell vehicle. The reason is that it is possible to capture regenerative braking energy and to operate the fuel cell system within a more efficient range by using battery. Life-cycle cost is largely affected by the fuel cell size, fuel cell cost, and hydrogen cost. When the cost of fuel cell is high, hybridization is profitable, but when the cost of fuel cell is less than 400 US$/kW, a pure fuel cell vehicle is more profitable.

Stocks, Flows, and Distribution of Critical Metals in Embedded Electronics in Passenger Vehicles.

Science.gov (United States)

Restrepo, Eliette; Løvik, Amund N; Wäger, Patrick; Widmer, Rolf; Lonka, Radek; Müller, Daniel B

2017-02-07

One of the major applications of critical metals (CMs) is in electrical and electronic equipment (EEE), which is increasingly embedded in other products, notably passenger vehicles. However, recycling strategies for future CM quantities in end-of-life vehicles (ELVs) are poorly understood, mainly due to a limited understating of the complexity of automotive embedded EEE. We introduce a harmonization of the network structure of automotive electronics that enables a comprehensive quantification of CMs in all embedded EEE in a vehicle. This network is combined with a material flow analysis along the vehicle lifecycle in Switzerland to quantify the stocks and flows of Ag, Au, Pd, Ru, Dy, La, Nd, and Co in automotive embedded EEE. In vehicles in use, we calculated 5 -2 +3 t precious metals in controllers embedded in all vehicle types and 220 -60 +90 t rare earth elements (REE); found mainly in five electric motors: alternator, starter, radiator-fan and electronic power steering motor embedded in conventional passenger vehicles and drive motor/generator embedded in hybrid and electric vehicles. Dismantling these devices before ELV shredding, as well as postshredder treatment of automobile shredder residue may increase the recovery of CMs from ELVs. Environmental and economic implications of such recycling strategies must be considered.

Vehicle Dynamic Prediction Systems with On-Line Identification of Vehicle Parameters and Road Conditions

Science.gov (United States)

Hsu, Ling-Yuan; Chen, Tsung-Lin

2012-01-01

This paper presents a vehicle dynamics prediction system, which consists of a sensor fusion system and a vehicle parameter identification system. This sensor fusion system can obtain the six degree-of-freedom vehicle dynamics and two road angles without using a vehicle model. The vehicle parameter identification system uses the vehicle dynamics from the sensor fusion system to identify ten vehicle parameters in real time, including vehicle mass, moment of inertial, and road friction coefficients. With above two systems, the future vehicle dynamics is predicted by using a vehicle dynamics model, obtained from the parameter identification system, to propagate with time the current vehicle state values, obtained from the sensor fusion system. Comparing with most existing literatures in this field, the proposed approach improves the prediction accuracy both by incorporating more vehicle dynamics to the prediction system and by on-line identification to minimize the vehicle modeling errors. Simulation results show that the proposed method successfully predicts the vehicle dynamics in a left-hand turn event and a rollover event. The prediction inaccuracy is 0.51% in a left-hand turn event and 27.3% in a rollover event. PMID:23202231

Adaptive Surveying and Early Treatment of Crops with a Team of Autonomous Vehicles

DEFF Research Database (Denmark)

Kazmi, Wajahat; Bisgaard, Morten; Garcia-Ruiz, Francisco

2011-01-01

The ASETA project (acronym for Adaptive Surveying and Early treatment of crops with a Team of Autonomous vehicles) is a multi-disciplinary project combining cooperating airborne and ground-based vehicles with advanced sensors and automated analysis to implement a smart treatment of weeds...... in agricultural fields. The purpose is to control and reduce the amount of herbicides, consumed energy and vehicle emissions in the weed detection and treatment process, thus reducing the environmental impact. The project addresses this issue through a closed loop cooperation among a team of unmanned aircraft...... system (UAS) and unmanned ground vehicles (UGV) with advanced vision sensors for 3D and multispectral imaging. This paper presents the scientific and technological challenges in the project, which include multivehicle estimation and guidance, heterogeneous multi-agent systems, task generation...

Recovery Act - Sustainable Transportation: Advanced Electric Drive Vehicle Education Program

Energy Technology Data Exchange (ETDEWEB)

Caille, Gary

2013-12-13

The collective goals of this effort include: 1) reach all facets of this society with education regarding electric vehicles (EV) and plug–in hybrid electric vehicles (PHEV), 2) prepare a workforce to service these advanced vehicles, 3) create web–based learning at an unparalleled level, 4) educate secondary school students to prepare for their future and 5) train the next generation of professional engineers regarding electric vehicles. The Team provided an integrated approach combining secondary schools, community colleges, four–year colleges and community outreach to provide a consistent message (Figure 1). Colorado State University Ventures (CSUV), as the prime contractor, plays a key program management and co–ordination role. CSUV is an affiliate of Colorado State University (CSU) and is a separate 501(c)(3) company. The Team consists of CSUV acting as the prime contractor subcontracted to Arapahoe Community College (ACC), CSU, Motion Reality Inc. (MRI), Georgia Institute of Technology (Georgia Tech) and Ricardo. Collaborators are Douglas County Educational Foundation/School District and Gooru (www.goorulearning.org), a nonprofit web–based learning resource and Google spin–off.

Robust Vehicle Detection in Aerial Images Based on Cascaded Convolutional Neural Networks.

Science.gov (United States)

Zhong, Jiandan; Lei, Tao; Yao, Guangle

2017-11-24

Vehicle detection in aerial images is an important and challenging task. Traditionally, many target detection models based on sliding-window fashion were developed and achieved acceptable performance, but these models are time-consuming in the detection phase. Recently, with the great success of convolutional neural networks (CNNs) in computer vision, many state-of-the-art detectors have been designed based on deep CNNs. However, these CNN-based detectors are inefficient when applied in aerial image data due to the fact that the existing CNN-based models struggle with small-size object detection and precise localization. To improve the detection accuracy without decreasing speed, we propose a CNN-based detection model combining two independent convolutional neural networks, where the first network is applied to generate a set of vehicle-like regions from multi-feature maps of different hierarchies and scales. Because the multi-feature maps combine the advantage of the deep and shallow convolutional layer, the first network performs well on locating the small targets in aerial image data. Then, the generated candidate regions are fed into the second network for feature extraction and decision making. Comprehensive experiments are conducted on the Vehicle Detection in Aerial Imagery (VEDAI) dataset and Munich vehicle dataset. The proposed cascaded detection model yields high performance, not only in detection accuracy but also in detection speed.

Autonomous Vehicles Have a Wide Range of Possible Energy Impacts

Energy Technology Data Exchange (ETDEWEB)

Austin Brown, Brittany Repac, Jeff Gonder

2013-07-15

Self-driving or “autonomous” vehicles (AVs) have leapt from science fiction into the forefront of transportation technology news. The technology is likely still years away from widespread commercial adoption, but the recent progress makes it worth considering the potential national impacts of widespread implementation. This poster makes an initial assessment of the energy impacts of AV adoptionon a per-vehicle basis and on total personal vehicle fuel use. While AVs offer numerous potential advantages in energy use, there are significant factors that could decrease or even eliminate the energy benefits under some circumstances. This analysis attempts to describe, quantify, and combine many of the possible effects. The nature and magnitude of these effects remain highly uncertain. This set of effects is very unlikely to be exhaustive, but this analysis approach can serve as a base for future estimates.

Conversion of Diesel Vehicles to Electric Vehicles and Controlled by PID Controller

OpenAIRE

Mengi, Onur Özdal

2017-01-01

Internal combustion engine vehicles are the most producedand sold vehicles on the market. In recent years, interest in electric vehicleshas begun to increase, especially due to the environmental problems. In thenear future, it is estimated that gasoline and diesel vehicles will becompletely electric vehicles. For this reason, many studies have been conductedon electric vehicles. Particularly the change of the engine parts, the turningof the internal combustion part to the electric motor, and ...

Battery control system for hybrid vehicle and method for controlling a hybrid vehicle battery

Science.gov (United States)

Bockelmann, Thomas R [Battle Creek, MI; Beaty, Kevin D [Kalamazoo, MI; Zou, Zhanijang [Battle Creek, MI; Kang, Xiaosong [Battle Creek, MI

2009-07-21

A battery control system for controlling a state of charge of a hybrid vehicle battery includes a detecting arrangement for determining a vehicle operating state or an intended vehicle operating state and a controller for setting a target state of charge level of the battery based on the vehicle operating state or the intended vehicle operating state. The controller is operable to set a target state of charge level at a first level during a mobile vehicle operating state and at a second level during a stationary vehicle operating state or in anticipation of the vehicle operating in the stationary vehicle operating state. The invention further includes a method for controlling a state of charge of a hybrid vehicle battery.

The Electric Vehicle Development

DEFF Research Database (Denmark)

Wang, Jingyu; Liu, Yingqi; Kokko, Ari

2014-01-01

In order to respond to the energy crisis and environment problem, countries carry out their research and promotion about electric vehicles. As the ten cities one thousand new energy buses started in 2009, the new energy vehicles have been greatly developed in China, while the development...... in three aspects-city environment, government and stakeholders. Then the paper discusses the promotion ways and role of government and consumer. Finally, the paper offers some suggestions to promote electric vehicles in China: focusing on feasibility and adaptability of electric vehicles, playing...... of electric vehicles is not that good. This paper selects four cities-Los Angeles, Kanagawa, Hamburg, Amsterdam-that promote electric vehicles successfully and deeply analyzes the development of electric vehicles in these four cities and analyzes the factors that affect the development of electric vehicles...

Analyzing Real-World Light Duty Vehicle Efficiency Benefits

Energy Technology Data Exchange (ETDEWEB)

Gonder, Jeffrey; Wood, Eric; Chaney, Larry; Holden, Jacob; Jeffers, Matthew; Wang, Lijuan

2016-06-08

Off-cycle technologies represent an important pathway to achieve real-world fuel savings, through which OEMs can potentially receive credit toward CAFE compliance. DOE national labs such as NREL are well positioned to provide objective input on these technologies using large, national data sets in conjunction with OEM- and technology-specific testing. This project demonstrates an approach that combines vehicle testing (dynamometer and on-road) with powertrain modeling and simulation over large, representative datasets to quantify real-world fuel economy. The approach can be applied to specific off-cycle technologies (engine encapsulation, start/stop, connected vehicle, etc.) in A/B comparisons to support calculation of realistic real-world impacts. Future work will focus on testing-based A/B technology comparisons that demonstrate the significance of this approach.

Mobilizing women at the grassroots to shape health policy: a case study of the Global Campaign for Microbicides.

Science.gov (United States)

Forbes, Anna

2013-11-01

Competition to advance issues on public policy agendas is constant. Political scientists agree that professional "policy entrepreneurs" (researchers, academics, and bureaucrats) serve as conduits in this process. Grassroots advocacy has always been part of the political landscape as non-professional people also take on the role of policy advocates or activists, to get specific problems and preferred solutions onto public and policy agendas and motivate policymakers to take action. The contribution of grassroots advocacy to significant policy changes is often under-funded because its impacts are hard to isolate and quantify, and are often most evident in retrospect. This paper examines the contribution of the Global Campaign for Microbicides to the movement to expand the range of HIV prevention options for women and describes how it mobilized hundreds of grassroots policy activists around the world to take coordinated action on this issue. It reviews the Campaign's accomplishments and highlights some of its strengths and weaknesses. Finally, the paper considers the value of similar efforts on the part of grassroots advocates seeking to influence the post-ICPD and post-2015 development agendas as they are being negotiated. Decisions regarding what kind of advocacy work is carried out during this process, and by whom and how, will inevitably shape the content of these new frameworks. Copyright © 2013 Reproductive Health Matters. Published by Elsevier Ltd. All rights reserved.

Routing Unmanned Vehicles in GPS-Denied Environments

OpenAIRE

Sundar, Kaarthik; Misra, Sohum; Rathinam, Sivakumar; Sharma, Rajnikant

2017-01-01

Most of the routing algorithms for unmanned vehicles, that arise in data gathering and monitoring applications in the literature, rely on the Global Positioning System (GPS) information for localization. However, disruption of GPS signals either intentionally or unintentionally could potentially render these algorithms not applicable. In this article, we present a novel method to address this difficulty by combining methods from cooperative localization and routing. In particular, the article...

Electric vehicles and renewable energy in the transport sector - energy system consequences. Main focus: Battery electric vehicles and hydrogen based fuel cell vehicles

DEFF Research Database (Denmark)

Nielsen, L.H.; Jørgensen K.

2000-01-01

The aim of the project is to analyse energy, environmental and economic aspects of integrating electric vehicles in the future Danish energy system. Consequences of large-scale utilisation of electric vehicles are analysed. The aim is furthermore toillustrate the potential synergistic interplay...... between the utilisation of electric vehicles and large-scale utilisation of fluctuating renewable energy resources, such as wind power. Economic aspects for electric vehicles interacting with a liberalisedelectricity market are analysed. The project focuses on battery electric vehicles and fuel cell...... vehicles based on hydrogen. Based on assumptions on the future technical development for battery electric vehicles, fuel cell vehicles on hydrogen, and forthe conventional internal combustion engine vehicles, scenarios are set up to reflect expected options for the long-term development of road transport...

International Conference on Heavy Vehicles HVParis 2008 : Heavy Vehicle Transport Technology (HVTT 10)

OpenAIRE

JACOB, Bernard; NORDENGEN, Paul; O'CONNOR, Alan; BOUTELDJA, Mohamed

2008-01-01

Sommaire : Heavy vehicles and WIM technology, testing and standards. Interactions between heavy vehicles or trains and the infrastructure, environment and other system users. Heavy vehicle and road management information: measurements, data quality, data management. Freight mobility and safety. Vehicle classification, size and weight evaluation, regulations and enforcement. Traffic and road safety. WIM of road vehicles, trains and aeroplanes.

Lane-Level Vehicle Trajectory Reckoning for Cooperative Vehicle-Infrastructure System

Directory of Open Access Journals (Sweden)

Yinsong Wang

2012-01-01

Full Text Available This paper presents a lane-level positioning method by trajectory reckoning without Global Positioning System (GPS equipment in the environment of Cooperative Vehicle-Infrastructure System (CVIS. Firstly, the accuracy requirements of vehicle position in CVIS applications and the applicability of GPS positioning methods were analyzed. Then, a trajectory reckoning method based on speed and steering data from vehicle’s Control Area Network (CAN and roadside calibration facilities was proposed, which consists of three critical models, including real-time estimation of steering angle and vehicle direction, vehicle movement reckoning, and wireless calibration. Finally, the proposed method was validated through simulation and field tests under a variety of traffic conditions. Results show that the accuracy of the reckoned vehicle position can reach the lane level and match the requirements of common CVIS applications.

How important is vehicle safety for older consumers in the vehicle purchase process?

Science.gov (United States)

Koppel, Sjaan; Clark, Belinda; Hoareau, Effie; Charlton, Judith L; Newstead, Stuart V

2013-01-01

This study aimed to investigate the importance of vehicle safety to older consumers in the vehicle purchase process. Older (n = 102), middle-aged (n = 791), and younger (n = 109) participants throughout the eastern Australian states of Victoria, New South Wales, and Queensland who had recently purchased a new or used vehicle completed an online questionnaire about their vehicle purchase process. When asked to list the 3 most important considerations in the vehicle purchase process (in an open-ended format), older consumers were mostly likely to list price as their most important consideration (43%). Similarly, when presented with a list of vehicle factors (such as price, design, Australasian New Car Assessment Program [ANCAP] rating), older consumers were most likely to identify price as the most important vehicle factor (36%). When presented with a list of vehicle features (such as automatic transmission, braking, air bags), older consumers in the current study were most likely to identify an antilock braking system (41%) as the most important vehicle feature, and 50 percent of older consumers identified a safety-related vehicle feature as the highest priority vehicle feature (50%). When asked to list up to 3 factors that make a vehicle safe, older consumers in the current study were most likely to list braking systems (35%), air bags (22%), and the driver's behavior or skill (11%). When asked about the influence of safety in the new vehicle purchase process, one third of older consumers reported that all new vehicles are safe (33%) and almost half of the older consumers rated their vehicle as safer than average (49%). A logistic regression model was developed to predict the profile of older consumers more likely to assign a higher priority to safety features in the vehicle purchasing process. The model predicted that the importance of safety-related features was influenced by several variables, including older consumers' beliefs that they could protect themselves

Full Vehicle Vibration and Noise Analysis Based on Substructure Power Flow

Directory of Open Access Journals (Sweden)

Zhien Liu

2017-01-01

Full Text Available Combining substructure and power flow theory, in this paper an external program is written to control MSC. Nastran solution process and the substructure frequency response are also formulated accordingly. Based on a simple vehicle model, characteristics of vibration, noise, and power flow are studied, respectively. After being compared with the result of conventional FEM (finite element method, the new method is confirmed to be feasible. When it comes to a vehicle with the problem of low-frequency noise, finite element models of substructures for vehicle body and chassis are established, respectively. In addition, substructure power flow method is also employed to examine the transfer characteristics of multidimensional vibration energy for the whole vehicle system. By virtue of the adjustment stiffness of drive shaft support and bushes at rear suspension lower arm, the vehicle interior noise is decreased by about 3 dB when the engine speed is near 1050 rpm and 1650 rpm in experiment. At the same time, this method can increase the computation efficiency by 78%, 38%, and 98% when it comes to the optimization of chassis structure, body structure, and vibration isolation components, respectively.