WorldWideScience

Sample records for junk wideband junk

  1. Toward Junking Junk Foods.

    Science.gov (United States)

    Lehmann, Phyllis E.

    1978-01-01

    Carroll County, Maryland, has shaped a strategy to improve school nutrition by weakening or eliminating, where possible, junk food competition, making lunches more nourishing and appealing, and working nutrition instruction into other subject areas. Steps taken to accomplish these changes are described. (MF)

  2. Sound Sleep May Help You Junk the Junk Food

    Science.gov (United States)

    ... html Sound Sleep May Help You Junk the Junk Food Well-rested workers less likely to overeat after ... HealthDay News) -- Get a good night's sleep and junk food may have less appeal at the end of ...

  3. JUNK: rubbish to gold

    OpenAIRE

    Hanson, Maria

    2015-01-01

    JUNK: rubbish to gold is a playful exploration of community economies (exchange, giving, bartering, gathering, earning, harvesting); putting on display the process of creating the ‘work of art’. Co-created and co-curated by Jivan Astfalck, Laura Bradshaw-Heap and Rachel Darbourne and partnered with charities, who supplied JUNK jewellery. During a public performance 31 jewellers ‘gifted’ their skills, (re)constructing pieces selected from a mountain of JUNK creating reimagined artworks for the...

  4. Of Junk Food and Junk Science

    OpenAIRE

    Collins, Robert A.; Baker, Gregory A.

    2009-01-01

    The popular press has triumphantly announced that the cause of the obesity epidemic is “junk food.†After a moment’s reflection, however, it seems likely that the true causal structure of the obesity epidemic can be neither single-equation nor univariate. Therefore, while the hypothesis that “junk food†is the cause of obesity has little a priori plausibility, these articles in the popular press present a testable hypothesis that, in spite of some measurement impossibilities, is teste...

  5. Quality Minus Junk

    DEFF Research Database (Denmark)

    Asness, Clifford S.; Frazzini, Andrea; Heje Pedersen, Lasse

    We define a quality security as one that has characteristics that, all-else-equal, an investor should be willing to pay a higher price for: stocks that are safe, profitable, growing, and well managed. High-quality stocks do have higher prices on average, but not by a very large margin. Perhaps...... because of this puzzlingly modest impact of quality on price, high-quality stocks have high risk-adjusted returns. Indeed, a quality-minus-junk (QMJ) factor that goes long high-quality stocks and shorts low-quality stocks earns significant risk-adjusted returns in the U.S. and globally across 24 countries....... The price of quality – i.e., how much investors pay extra for higher quality stocks – varies over time, reaching a low during the internet bubble. Further, a low price of quality predicts a high future return of QMJ. Finally, controlling for quality resurrects the otherwise moribund size effect....

  6. Junk Food in Schools and Childhood Obesity

    Science.gov (United States)

    Datar, Ashlesha; Nicosia, Nancy

    2012-01-01

    Despite limited empirical evidence, there is growing concern that junk food availability in schools has contributed to the childhood obesity epidemic. In this paper, we estimate the effects of junk food availability on body mass index (BMI), obesity, and related outcomes among a national sample of fifth graders. Unlike previous studies, we address…

  7. Junk Food in Schools and Childhood Obesity

    Science.gov (United States)

    Datar, Ashlesha; Nicosia, Nancy

    2012-01-01

    Despite limited empirical evidence, there is growing concern that junk food availability in schools has contributed to the childhood obesity epidemic. In this paper, we estimate the effects of junk food availability on body mass index (BMI), obesity, and related outcomes among a national sample of fifth graders. Unlike previous studies, we address…

  8. Junk Food in Schools and Childhood Obesity

    OpenAIRE

    Datar, Ashlesha; Nicosia, Nancy

    2012-01-01

    Despite limited empirical evidence, there is growing concern that junk food availability in schools has contributed to the childhood obesity epidemic. In this paper, we estimate the effects of junk food availability on BMI, obesity, and related outcomes among a national sample of fifth-graders. Unlike previous studies, we address the endogeneity of the school food environment by controlling for children’s BMI at school entry and estimating instrumental variables regressions that leverage vari...

  9. Junk Food in Schools and Childhood Obesity

    OpenAIRE

    Datar, Ashlesha; Nicosia, Nancy

    2012-01-01

    Despite limited empirical evidence, there is growing concern that junk food availability in schools has contributed to the childhood obesity epidemic. In this paper, we estimate the effects of junk food availability on BMI, obesity, and related outcomes among a national sample of fifth-graders. Unlike previous studies, we address the endogeneity of the school food environment by controlling for children’s BMI at school entry and estimating instrumental variables regressions that leverage vari...

  10. "Junk" DNA as a genetic decoy

    OpenAIRE

    Magueijo, Joao

    2003-01-01

    We propose that the evolutionary purpose of junk DNA is to protect the gene. Mutation agents, such as retro-viruses, hit ``decoy'' DNA most of the time. Although the argument is far from general, we propose that the percentage of junk DNA should correlate with the number of retroviruses attacking a given species. It should also anti-correlate with the ideal mutation rates (higher in insects than in mammals).

  11. Junk Food in Schools and Childhood Obesity.

    Science.gov (United States)

    Datar, Ashlesha; Nicosia, Nancy

    2012-01-01

    Despite limited empirical evidence, there is growing concern that junk food availability in schools has contributed to the childhood obesity epidemic. In this paper, we estimate the effects of junk food availability on BMI, obesity, and related outcomes among a national sample of fifth-graders. Unlike previous studies, we address the endogeneity of the school food environment by controlling for children's BMI at school entry and estimating instrumental variables regressions that leverage variation in the school's grade span. Our main finding is that junk food availability does not significantly increase BMI or obesity among this fifth grade cohort despite the increased likelihood of in-school junk food purchases. The results are robust to alternate measures of junk food availability including school administrator reports of sales during school hours, school administrator reports of competitive food outlets, and children's reports of junk food availability. Moreover, the absence of any effects on overall food consumption and physical activity further support the null findings for BMI and obesity.

  12. A Theory of LTR Junk-food Consumption

    OpenAIRE

    Levy, Amnon

    2003-01-01

    LTR junk-food consumption balances the marginal satisfaction with the marginal deterioration of health. An LTR person discounts the instantaneous marginal satisfaction from junk-food consumption by its implications for his survival probability. His change rate of health evaluation is increased (decreased) by junk-food consumption when health is better (worse) than a critical level. The moderating direct effects of age and relative price on junk-food consumption may be amplified, or dimmed, by...

  13. A Theory of Rational Junk-Food Consumption

    OpenAIRE

    Levy, Amnon

    2002-01-01

    An expected lifetime-utility maximizing diet of junk and health food is analyzed. The stationary junk-food consumption level is equal to the ratio of the recovery capacity of a perfectly healthy person to the sensitivity of her health to junk food. The greater the difference between the relative taste and the stationary relative price of junk food, rate of time preference, and elasticity of satisfaction from food, the better the stationary health of the rational junk-food consumer. The greate...

  14. Taxing junk food to counter obesity.

    Science.gov (United States)

    Franck, Caroline; Grandi, Sonia M; Eisenberg, Mark J

    2013-11-01

    We examined the advantages and disadvantages of implementing a junk food tax as an intervention to counter increasing obesity in North America. Small excise taxes are likely to yield substantial revenue but are unlikely to affect obesity rates. High excise taxes are likely to have a direct impact on weight in at-risk populations but are less likely to be politically palatable or sustainable. Ultimately, the effectiveness of earmarked health programs and subsidies is likely to be a key determinant of tax success in the fight against obesity.

  15. The effects of banning advertising in junk food markets

    OpenAIRE

    Dubois, Pierre; Griffith, Rachel; O'Connell, Martin

    2017-01-01

    There are growing calls to restrict advertising of junk foods. Whether such a move will improve diet quality will depend on how advertising shifts consumer demands and how firms respond. We study an important and typical junk food market { the potato chips market. We exploit consumer level exposure to adverts to estimate demand, allowing advertising to potentially shift the weight consumers place on product healthiness, tilt demand curves, have dynamic effects and spillover effects across bra...

  16. How Some School Boards Are Fighting (and Why More Are Tolerating) Junk Foods in Schools

    Science.gov (United States)

    Aburdene, Patricia

    1977-01-01

    While some school boards refuse to ban junk foods because of the loss of revenue that would result, other boards and administrators are successfully banning junk foods and finding alternatives to them. (IRT)

  17. Paparan iklan junk food dan pola konsumsi junk food sebagai faktor risiko terjadinya obesitas pada anak sekolah dasar kota dan desa di Daerah Istimewa Yogyakarta

    OpenAIRE

    Esti Nurwanti; Hamam Hadi; Madarina Julia

    2016-01-01

    ABSTRACTBackground: Increasing prevalence of obesity may be caused by junk food advertised while children are watching television.Preference for foods requested by the children is much infl uenced by junk food advertisement, so that it can affect calori intakeand correlates with obesity. Obesity in children can cause obesity during adulthood and may increase the risk of degenerativedisease, like diabetes and cardiovascular.Objective: To analyze the level of risk exposure to junk food advertisi...

  18. Konsumsi Junk Food dan Hipertensi pada Lansia di Kecamatan Kasihan, Bantul, Yogyakarta

    Directory of Open Access Journals (Sweden)

    Rantiningsih Sumarni

    2015-07-01

    Full Text Available The risk of hypertension increases in line with a changes in modern lifestyle. Elderly tends to select food such as junk food with high calories, and fat, but low in fi ber and other nutrients. Junk food contains high amounts of sodium that can increase the volume of blood in the body, so make stronger heart blood pumps and cause the higher blood pressure (hypertension. The purpose of this study was to identify the relationship between junk food consumption and hypertension in elderly in Kasihan sub-district Bantul, Yogyakarta. This was an observational analytic study with cross sectional design. The samples were 100 elderly lives in Kasihan sub-district Bantul, Yogyakarta. The results showed that there was relationship between the consumption of junk food and hypertension. Respondents who suffered from hypertension were 49 (67.1% who often consumed junk food and 24 respondents (32.9% who rarely consumed junk food. Respondents who did not undergo hypertension were 9 respondents (33.3% that often consumed junk food and 18 respondents (66.7% that rarely consumed junk food. In conclusion, there was a relationship between junk food consumption and hypertension in elderly. Risk of hypertension in respondents who consumed more often junk food were 4.083 times higher than them who rarely consumed junk food.

  19. Time to Take a Stand against Junk Food.

    Science.gov (United States)

    Jacobsen, Michael

    1993-01-01

    Childhood obesity is a social and health problem that is encouraged by junk food ads and the easy availability of unhealthful fast foods. The article provides guidance for parents to encourage healthy eating by their children; it includes a list of resources and a list of "best" processed foods. (SM)

  20. [Junk food consumption and child nutrition. Nutritional anthropological analysis].

    Science.gov (United States)

    Jackson, Portia; Romo, Marcela M; Castillo, Marcela A; Castillo-Durán, Carlos

    2004-10-01

    The increasing consumption of junk food and snacks in Chile in recent years and its association with marketing strategies and prevalent diseases, is reviewed. In the context of world economy, junk food is a global phenomenon. The availability of junk food and snacks at low prices and marketing has triggered an evolution of consumption of foods that require neither the structure nor the preparation of a formal meal. Many studies have suggested that the increase in snack consumption is associated with an increase in obesity, tooth decay and other chronic diseases among children and adolescents. The hypothesis suggests a link between the pattern of snack consumption and an increase increase in the energy density of food consumed, a decrease in satiety, passive over consumption, and an increase in obesity. Between 1977 and 1996, the contribution: of snacks to daily energy intake among children between 2 and 5 years increased by 30% in the United States. In each age group in Chile the frequency of non-transmissible chronic diseases is increasing due primarily to a westernized diet that is high in fat, cholesterol, sodium, and sugar and a sedentary lifestyle. Education about junk food consumption and healthy eating habits in the family, starling since childbirth and public policies about healthy lifestyles should be strengthened.

  1. A Force Transducer from a Junk Electronic Balance

    Science.gov (United States)

    Aguilar, Horacio Munguia; Aguilar, Francisco Armenta

    2009-01-01

    It is shown how the load cell from a junk electronic balance can be used as a force transducer for physics experiments. Recovering this device is not only an inexpensive way of getting a valuable laboratory tool but also very useful didactic work on electronic instrumentation. Some experiments on mechanics with this transducer are possible after a…

  2. A Force Transducer from a Junk Electronic Balance

    Science.gov (United States)

    Aguilar, Horacio Munguia; Aguilar, Francisco Armenta

    2009-01-01

    It is shown how the load cell from a junk electronic balance can be used as a force transducer for physics experiments. Recovering this device is not only an inexpensive way of getting a valuable laboratory tool but also very useful didactic work on electronic instrumentation. Some experiments on mechanics with this transducer are possible after a…

  3. Time to Take a Stand against Junk Food.

    Science.gov (United States)

    Jacobsen, Michael

    1993-01-01

    Childhood obesity is a social and health problem that is encouraged by junk food ads and the easy availability of unhealthful fast foods. The article provides guidance for parents to encourage healthy eating by their children; it includes a list of resources and a list of "best" processed foods. (SM)

  4. Attack of the Junk Food Giant: Giving Children and Teens a Taste for Nutrition in an Age of Super Size Portions and Junk Food.

    Science.gov (United States)

    Anderson, Marilyn

    2001-01-01

    Discusses what parents can do to ensure their children's healthy eating, examining whether students are eating school lunches or junk food in the cafeteria; discussing junk food temptations outside of school; noting rising soda consumption rates; and presenting advice for healthy eating (e.g., include children in meal planning and preparation and…

  5. Attack of the Junk Food Giant: Giving Children and Teens a Taste for Nutrition in an Age of Super Size Portions and Junk Food.

    Science.gov (United States)

    Anderson, Marilyn

    2001-01-01

    Discusses what parents can do to ensure their children's healthy eating, examining whether students are eating school lunches or junk food in the cafeteria; discussing junk food temptations outside of school; noting rising soda consumption rates; and presenting advice for healthy eating (e.g., include children in meal planning and preparation and…

  6. Alu Mobile Elements: From Junk DNA to Genomic Gems

    Directory of Open Access Journals (Sweden)

    Sami Dridi

    2012-01-01

    Full Text Available Alus, the short interspersed repeated sequences (SINEs, are retrotransposons that litter the human genomes and have long been considered junk DNA. However, recent findings that these mobile elements are transcribed, both as distinct RNA polymerase III transcripts and as a part of RNA polymerase II transcripts, suggest biological functions and refute the notion that Alus are biologically unimportant. Indeed, Alu RNAs have been shown to control mRNA processing at several levels, to have complex regulatory functions such as transcriptional repression and modulating alternative splicing and to cause a host of human genetic diseases. Alu RNAs embedded in Pol II transcripts can promote evolution and proteome diversity, which further indicates that these mobile retroelements are in fact genomic gems rather than genomic junks.

  7. Identity Theft in the Academic World Leads to Junk Science.

    Science.gov (United States)

    Dadkhah, Mehdi; Lagzian, Mohammad; Borchardt, Glenn

    2017-01-10

    In recent years, identity theft has been growing in the academic world. Cybercriminals create fake profiles for prominent scientists in attempts to manipulate the review and publishing process. Without permission, some fraudulent journals use the names of standout researchers on their editorial boards in the effort to look legitimate. This opinion piece, highlights some of the usual types of identity theft and their role in spreading junk science. Some general guidelines that editors and researchers can use against such attacks are presented.

  8. Junk DNA-Encoded Antigens in Ovarian Cancer

    Science.gov (United States)

    2014-10-01

    SUBTITLE Junk DNA-Encoded Antigens in Ovarian Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-13-1-0359 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR...ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER The Johns Hopkins University School of Medicine 733 North Broadway, Suite 117 ...recombinase inactivates homozygous floxed alleles of p53 and Rb1. We also increased our understanding of aberrant ORF1p long interspersed element -1

  9. Frequency of biofilm formation in toothbrushes and wash basin junks

    Directory of Open Access Journals (Sweden)

    Abdulazeez A Abubakar

    2013-01-01

    Full Text Available Background: Biofilms are known to be resistant to several antibiotics once they are allowed to form on any surface. Aim: To investigate the biofilm forming ability of some bacterial isolates in toothbrushes and wash basin junks. Materials and Methods: A total of 606 students of Federal University of Technology, Yola were provided with new toothbrushes, which were collected after 1 month of usage and screened for biofilm formation. Another 620 swabs were collected from the wash basins of Federal Medical Centre, Specialist Hospital, Federal University of Technology, and students′ hostels in Yola and from some residence in Jimeta, Yola Metropolis; they were all screened for biofilm formation. Results: A total of 38.3% biofilm formation rate was recorded. Three types of bacterial isolates were identified in the biofilms of toothbrushes and wash basin junks, namely Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa at the prevalence rate of 48.0%, 29.1%, and 22.6%, respectively. Overall, 83.3% of the toothbrush biofilm were identified from female students, while 16.7% were from their male counterparts. Statistically, the frequency of biofilm formation showed a significant difference by gender (X 2 = 10.242, P 0.05. Conclusion: This study identified three microorganisms namely S. aureus, E. coli, and P. aeruginosa that were involved in wash basin junk biofilm formation. The findings also showed that occurrence of biofilm in females′ toothbrushes were significantly higher than in males′ (X 2 = 10.242, P < 0.05.

  10. Junk food consumption and screen time: association with childhood adiposity.

    Science.gov (United States)

    Montoye, Alexander H; Pfeiffer, Karin A; Alaimo, Katherine; Betz, Heather Hayes; Paek, Hye-Jin; Carlson, Joseph J; Eisenmann, Joey C

    2013-05-01

    To determine the joint association of junk food consumption (JFC) and screen time (ST) with adiposity in children. Two hundred fourteen (121 girls, 93 boys) third-to-fifth-grade students (54% Hispanic, 35% African American, 8% white) completed a lifestyle behavior survey, which included self-reported JFC and ST, as part of a school-based lifestyle intervention program. Neither JFC nor ST, independently or jointly, was associated with adiposity measures. JFC and ST were significantly correlated (r = .375). The low achievement of physical activity and screen time recommendations and high prevalence of overweight/obesity in this mostly minority, low socioeconomic status population indicates a potential focus for intervention.

  11. The impact of a junk-food diet during development on 'wanting' and 'liking'.

    Science.gov (United States)

    Lesser, Ellen Nacha; Arroyo-Ramirez, Aime; Mi, Sarah Jingyi; Robinson, Mike James Ferrar

    2017-01-15

    The global increase in obesity rates has been tied to the rise in junk-food availability and consumption. Increasingly, children are exposed to a junk-food diet during gestation and early development. Excessive consumption of junk-food during this period may negatively impact the development of brain motivation and reward pathways. In this study we investigated the effects of a chronic junk-food diet throughout development on cue-motivated behavior ('wanting'), hedonic 'liking' for sweet tastes, as well as anxiety and weight gain in male and female Long-Evans (LE) and Sprague-Dawley (SD) rats. Here we found that chronic exposure to a junk-food diet resulted in large individual differences in weight gain (gainers and non-gainers) despite resulting in stunted growth as compared to chow-fed controls. Behaviorally, junk-food exposure attenuated conditioned approach (autoshaping) in females, particularly in non-gainers. In contrast, junk-food exposed rats that gained the most weight were willing to work harder for access to a food cue (conditioned reinforcement), and were more attracted to a junk-food context (conditioned place preference) than non-gainers. Hedonic 'liking' reactions (taste reactivity) were severely blunted in LE, but not SD rats, and 'liking' for sucrose negatively correlated with greater weight gain. Finally, junk-food exposure reduced anxiety-like behavior (elevated plus maze) in males but not females. These results suggest that junk-food exposure during development may give rise to dissociable differences in 'liking' and 'wanting' neural systems that do not depend on weight gain and may not be detected through Body Mass Index monitoring alone.

  12. A maternal 'junk food' diet in pregnancy and lactation promotes an exacerbated taste for 'junk food' and a greater propensity for obesity in rat offspring.

    Science.gov (United States)

    Bayol, Stéphanie A; Farrington, Samantha J; Stickland, Neil C

    2007-10-01

    Obesity is generally associated with high intake of junk foods rich in energy, fat, sugar and salt combined with a dysfunctional control of appetite and lack of exercise. There is some evidence to suggest that appetite and body mass can be influenced by maternal food intake during the fetal and suckling life of an individual. However, the influence of a maternal junk food diet during pregnancy and lactation on the feeding behaviour and weight gain of the offspring remains largely uncharacterised. In this study, six groups of rats were fed either rodent chow alone or with a junk food diet during gestation, lactation and/or post-weaning. The daily food intakes and body mass were measured in forty-two pregnant and lactating mothers as well as in 216 offspring from weaning up to 10 weeks of age. Results showed that 10 week-old rats born to mothers fed the junk food diet during gestation and lactation developed an exacerbated preference for fatty, sugary and salty foods at the expense of protein-rich foods when compared with offspring fed a balanced chow diet prior to weaning or during lactation alone. Male and female offspring exposed to the junk food diet throughout the study also exhibited increased body weight and BMI compared with all other offspring. This study shows that a maternal junk food diet during pregnancy and lactation may be an important contributing factor in the development of obesity.

  13. Taxing junk food: applying the logic of the Henry tax review to food.

    Science.gov (United States)

    Bond, Molly E; Williams, Michael J; Crammond, Brad; Loff, Bebe

    2010-10-18

    The recent review of taxation in Australia - the Henry tax review - has recommended that the federal government increase the taxes already levied on tobacco and alcohol. Tobacco and alcohol taxes are put forward as the best way of reducing the social harms caused by the use and misuse of these substances. Junk foods have the same pattern of misuse and the same social costs as tobacco and alcohol. The Henry tax review rejects the idea of taxing fatty foods, and to date the government has not implemented a tax on junk food. We propose that a tax on junk food be implemented as a tool to reduce consumption and address the obesity epidemic.

  14. Konsumsi Junk Food dan Hipertensi pada Lansia di Kecamatan Kasihan, Bantul, Yogyakarta

    OpenAIRE

    Rantiningsih Sumarni; Edi Sampurno; Veriani Aprilia

    2015-01-01

    The risk of hypertension increases in line with a changes in modern lifestyle. Elderly tends to select food such as junk food with high calories, and fat, but low in fi ber and other nutrients. Junk food contains high amounts of sodium that can increase the volume of blood in the body, so make stronger heart blood pumps and cause the higher blood pressure (hypertension). The purpose of this study was to identify the relationship between junk food consumption and hypertension in elderly in Kasi...

  15. Paparan iklan junk food dan pola konsumsi junk food sebagai faktor risiko terjadinya obesitas pada anak sekolah dasar kota dan desa di Daerah Istimewa Yogyakarta

    Directory of Open Access Journals (Sweden)

    Esti Nurwanti

    2016-03-01

    Full Text Available ABSTRACTBackground: Increasing prevalence of obesity may be caused by junk food advertised while children are watching television.Preference for foods requested by the children is much infl uenced by junk food advertisement, so that it can affect calori intakeand correlates with obesity. Obesity in children can cause obesity during adulthood and may increase the risk of degenerativedisease, like diabetes and cardiovascular.Objective: To analyze the level of risk exposure to junk food advertising and junk food consumption on the incidence of obesityin primary school children in elementary school children at the area of Yogyakarta Municipality and District of Bantul.Method: This study was an observational study with case-control design. The study population was elementary school childrenin the City of Yogyakarta and Bantul Regency. Cases were elementary school children who were obese, while the controlswere children who were not obese and sat closest the cases regardless of age and sex. Number of subjects for each groupwere 244 (1:1. Obesity was defi ned as BMI / U>95th percentile curves NCHS/CDC. Sampling to fi nd obesity with probabilityproportional to size (PPS and sampling for cases and controls using random sampling techniques. Univariate analysis ofthe data using frequency distributions, bivariate analysis using Chi-square, and multivariate analysis using multiple logisticregression. Data were analyzed using STATA 11 program with a 95% signifi cance level and nutrisurvey.Result: Bivariate analysis using Chi Square shows the variables that infl uence the incidence of obesity, such as junkfood ads exposure (OR=1.70, 95%CI: 1.17-2.48, and p=0.004, junk food energy intake (OR=1.58, 95%CI:  1.08-2.32and p=0.01, intake of saturated fat junk food (OR=1.74, 95%CI: 1.18-2.56 and p=0.004, sodium intake of junk food(OR=1.83, 95%CI: 1.25-2.69 and p=0.001 and sex (OR=0.58, 95%CI: 0.40-0.85 and p= 0.0035. Multivariate analysiswith logistic

  16. Comparing children's GPS tracks with geospatial proxies for exposure to junk food.

    Science.gov (United States)

    Sadler, Richard C; Gilliland, Jason A

    2015-01-01

    Various geospatial techniques have been employed to estimate children's exposure to environmental cardiometabolic risk factors, including junk food. But many studies uncritically rely on exposure proxies which differ greatly from actual exposure. Misrepresentation of exposure by researchers could lead to poor decisions and ineffective policymaking. This study conducts a GIS-based analysis of GPS tracks--'activity spaces'--and 21 proxies for activity spaces (e.g. buffers, container approaches) for a sample of 526 children (ages 9-14) in London, Ontario, Canada. These measures are combined with a validated food environment database (including fast food and convenience stores) to create a series of junk food exposure estimates and quantify the errors resulting from use of different proxy methods. Results indicate that exposure proxies consistently underestimate exposure to junk foods by as much as 68%. This underestimation is important to policy development because children are exposed to more junk food than estimated using typical methods.

  17. Junk food seen at pediatric clinic visits: is it a problem?

    Science.gov (United States)

    Frazier, Johnnie P; Land, Megan; Hsieh, Pei-Hsuan; Barratt, Michelle S

    2014-04-01

    To document the prevalence of junk foods seen at clinic visits. A cross-sectional 23-item survey of observed food items were completed by medical staff using a convenience sample of families from June 2, 2011 to March 2, 2012. The study was conducted in pediatric clinics affiliated with the University of Texas Medical School at Houston. A convenience sample consisting of 738 families with children from 4 months to 16 years old presenting for visits were included in the study. Children exclusively breast and formula fed was excluded. Junk food was observed 20.9% at the clinic visits. Junk food was often seen at clinic visits. There was a trend toward higher body mass index in patients whose families had junk food at the visit.

  18. Hubungan Konsumsi Junk Food dengan Status Gizi Lebih pada Siswa SD Pertiwi 2 Padang

    OpenAIRE

    Rizki Nur Amalia; Delmi Sulastri; Rima Semiarty

    2016-01-01

    AbstrakGizi lebih adalah keadaan tubuh seseorang yang mengalami berat badan berlebih karena kelebihan jumlah asupan energi yang disimpan dalam bentuk cadangan berupa lemak. Prevalensi gizi lebih pada anak di Indonesia mencapai 10,4. Salah satu faktor risiko terjadinya gizi lebih adalah kebiasaan mengonsumsi junk food. Tujuan penelitian ini adalah menentukan hubungan antara konsumsi junk food dengan status gizi lebih pada anak usia sekolah. Penelitian ini adalah penelitian analitik dengan ranc...

  19. Immature psychological defense mechanisms are associated with greater personal importance of junk food, alcohol, and television.

    Science.gov (United States)

    Costa, Rui Miguel; Brody, Stuart

    2013-10-30

    Immature psychological defense mechanisms are psychological processes that play an important role in suppressing emotional awareness and contribute to psychopathology. In addition, unhealthy food, television viewing, and alcohol consumption can be among the means to escape self-awareness. In contrast, engaging in, and responding fully to specifically penile-vaginal intercourse (PVI) is associated with indices of better emotional regulation, including less use of immature defense mechanisms. There was a lack of research on the association of immature defense mechanisms with personal importance of junk food, alcohol, television, PVI, and noncoital sex. In an online survey, 334 primarily Scottish women completed the Defense Style Questionnaire (DSQ-40), and rated the personal importance of junk food, alcohol, television, PVI, and noncoital sex. Immature defense mechanisms correlated with importance of junk food, alcohol, and television. Importance of PVI correlated with mature defenses, and less use of some component immature defenses. Importance of alcohol correlated with importance of junk food, television, and noncoital sex. Importance of junk food was correlated with importance of television and noncoital sex. The findings are discussed in terms of persons with poorer self-regulatory abilities having more interest in junk food, television, and alcohol, and less interest in PVI.

  20. Assessing junk food consumption among Australian children: trends and associated characteristics from a cross-sectional study

    OpenAIRE

    Boylan, S; L.L. Hardy; Drayton, B. A.; Grunseit, A.; Mihrshahi, S

    2017-01-01

    Background The ubiquitous supply of junk foods in our food environment has been partly blamed for the increased rates in overweight and obesity. However, consumption of these foods has generally been examined individually perhaps obscuring the true extent of their combined consumption and impact on health. An overall measure of children?s junk food consumption may prove useful in the development of child obesity prevention strategies. We describe the development of a children?s Junk Food Inta...

  1. Hubungan Konsumsi Junk Food dengan Status Gizi Lebih pada Siswa SD Pertiwi 2 Padang

    Directory of Open Access Journals (Sweden)

    Rizki Nur Amalia

    2016-01-01

    Full Text Available AbstrakGizi lebih adalah keadaan tubuh seseorang yang mengalami berat badan berlebih karena kelebihan jumlah asupan energi yang disimpan dalam bentuk cadangan berupa lemak. Prevalensi gizi lebih pada anak di Indonesia mencapai 10,4. Salah satu faktor risiko terjadinya gizi lebih adalah kebiasaan mengonsumsi junk food. Tujuan penelitian ini adalah menentukan hubungan antara konsumsi junk food dengan status gizi lebih pada anak usia sekolah. Penelitian ini adalah penelitian analitik dengan rancangan cross sectional terhadap populasi penelitian yaitu siswa kelas 1 – 5 di SD Pertiwi 2 Padang sebanyak 250 siswa. Teknik pengambilan data dilakukan dengan menggunakan kuesioner semi kuantitatif FFQ.  Status gizi ditentukan dengan pengukuran berat badan dan tinggi badan yang hasilnya dikategorikan menggunakan standar antropometri penilaian status gizi anak menurut Depkes Indonesia. Pada hasil penelitian didapatkan bahwa siswa yang memiliki status gizi lebih hanya 23,6% dengan rata – rata IMT 16,9±3,69. Rata – rata frekuensi konsumsi junk food 4,6±2,9 kali per hari dan rata – rata asupan energi junk food 1046,5±918,4 kkal per hari. Kesimpulan penelitian ini adalah terdapat hubungan yang bermakna antara konsumsi frekuensi konsumsi junk food dengan kejadian gizi lebih (p = 0,013 dan tidak terdapat hubungan yang bermakna antara asupan energi junk food dengan kejadian gizi lebih (p = 0,120.Kata kunci: gizi lebih, junk food, FFQ AbstractOverweight is a condition of an individual who suffer from excessive weight due to an excess of energy intake stored in fat tissue. Prevalence of overweight in children in Indonesia reaches 10,4 %. One of the risk factors contributing to this condition is consuming junk food. The objective of this study was to identify the relationship of junk food consumption and overweight in students. This research is an analytic study conducted in a cross sectional design using 250  students of class 1-5 in SD Pertiwi 2 Padang

  2. Persistent junk solutions in time-domain modeling of extreme mass ratio binaries

    CERN Document Server

    Field, Scott E; Lau, Stephen R

    2010-01-01

    In the context of metric perturbation theory for non-spinning black holes, extreme mass ratio binary (EMRB) systems are described by distributionally forced master wave equations. Numerical solution of a master wave equation as an initial boundary value problem requires initial data. However, because the correct initial data for generic-orbit systems is unknown, specification of trivial initial data is a common choice, despite being inconsistent and resulting in a solution which is initially discontinuous in time. As is well known, this choice leads to a "burst" of junk radiation which eventually propagates off the computational domain. We observe another unintended consequence of trivial initial data: development of a persistent spurious solution, here referred to as the Jost junk solution, which contaminates the physical solution for long times. This work studies the influence of both types of junk on metric perturbations, waveforms, and self-force measurements, and it demonstrates that smooth modified sour...

  3. Attitudinal Ambivalence as a Protective Factor Against Junk Food Advertisements: A Moderated Mediation Model of Behavioral Intention.

    Science.gov (United States)

    Ran, Weina; Yamamoto, Masahiro

    2015-08-01

    This study investigates the role of attitudinal ambivalence in moderating the effects of junk food advertisements on behavioral intentions by tapping different facets of this construct-felt ambivalence, potential ambivalence, and affective-cognitive ambivalence. Results based on an online survey of college students indicate that attention to junk food advertisements has an indirect positive effect on intentions to eat junk food through its positive effect on attitudes toward junk food. A moderated mediation model reveals that this indirect effect of junk food advertisements is weakened as respondents' levels of felt ambivalence increase. This moderating role is not observed for the measures of potential ambivalence and affective-cognitive ambivalence. Implications are discussed for health interventions.

  4. Assessing junk food consumption among Australian children: trends and associated characteristics from a cross-sectional study.

    Science.gov (United States)

    Boylan, S; Hardy, L L; Drayton, B A; Grunseit, A; Mihrshahi, S

    2017-04-05

    The ubiquitous supply of junk foods in our food environment has been partly blamed for the increased rates in overweight and obesity. However, consumption of these foods has generally been examined individually perhaps obscuring the true extent of their combined consumption and impact on health. An overall measure of children's junk food consumption may prove useful in the development of child obesity prevention strategies. We describe the development of a children's Junk Food Intake Measure (JFIM) to summarise temporal change in junk food consumption and examine the association between the JFIM and health-related behaviours. Cross-sectional population surveillance survey of Australian children age 5-16 years collected in 2010 and 2015. Data were collected by questionnaire with parent's proxy reporting for children in years K, 2 and 4 and children in years 6, 8 and 10 by self-report. Information on diet, screen-time and physical activity was collected using validated questionnaires. The JFIM comprised consumption of fried potato products, potato crisps/salty snacks, sweet and savoury biscuits/cakes/doughnuts, confectionary and, ice cream/ice blocks. A total of 7565 (missing = 493, 6.1%) and 6944 (missing n = 611, 8.1%) children had complete data on consumption of junk foods, in 2010 and 2015, respectively. The 2015 survey data showed that among students from high socio-economic status neighbourhoods, there were fewer high junk food consumers than low junk food consumers. Children from Middle Eastern cultural backgrounds had higher junk food consumption. High junk food consumers were more likely to consume take-away ≥3/week, eat dinner in front of the television, receive sweet rewards, be allowed to consume snacks anytime, have soft drinks available at home and a TV in their bedroom. There was a lower proportion of high junk food consumers in 2015 compared to 2010. This is the first study to provide and examine a summary measure of overall junk food

  5. Food as Risk: How Eating Habits and Food Knowledge Affect Reactivity to Pictures of Junk and Healthy Foods.

    Science.gov (United States)

    Yegiyan, Narine S; Bailey, Rachel L

    2016-01-01

    This study explores how people respond to images of junk versus healthy food as a function of their eating habits and food knowledge. The experiment reported here proposed and tested the idea that those with unhealthy eating habits but highly knowledgeable about healthy eating would feel more positive and also more negative toward junk food images compared to images of healthy food because they may perceive them as risky--desirable but potentially harmful. The psychophysiological data collected from participants during their exposure to pictures of junk versus healthy food supported this idea. In addition, unhealthy eaters compared to healthy eaters with the same degree of food knowledge responded more positively to all food items. The findings are critical from a health communication perspective. Because unhealthy eaters produce stronger emotional responses to images of junk food, they are more likely to process information associated with junk food with more cognitive effort and scrutiny. Thus, when targeting this group and using images of junk food, it is important to combine these images with strong message claims and relevant arguments; otherwise, if the arguments are perceived as irrelevant or weak, the motivational activation associated with junk food itself may transfer into an increased desire to consume the unhealthy product.

  6. Junk food” diet and childhood behavioural problems: Results from the ALSPAC cohort

    Science.gov (United States)

    Wiles, Nicola J; Northstone, Kate; Emmett, Pauline; Lewis, Glyn

    2007-01-01

    Objective To determine whether a “junk food” diet at age 4½ is associated with behavioural problems at age 7. Subjects and Methods Data on approximately 4000 children participating in the Avon Longitudinal Study of Parents and Children (ALSPAC), a birth cohort recruited in Avon, UK in 1991/92, were used. Behavioural problems were measured at age 7 using the Strengths & Difficulties Questionnaire (SDQ) (maternal completion). Total difficulties and scores for the 5 sub-scales (hyperactivity, conduct & peer problems, emotional symptoms, & prosocial behaviour) were calculated. Principal components analysis of dietary data (frequency of consumption of 57 foods/drinks) collected at age 4½ by maternal report was used to generate a “junk food” factor. Data on confounders were available from questionnaires. Results A one standard deviation increase in “junk food” intake at age 4½ years was associated with increased hyperactivity at age 7 (odds ratio: 1.19 (95% confidence interval: 1.10, 1.29)). This persisted after adjustment for confounders including IQ score (odds ratio: 1.13 (95% confidence interval: 1.01, 1.15)). There was little evidence to support an association between “junk food” intake and overall behavioural difficulties or other sub-scales of the SDQ. Conclusions Children eating a diet high in “junk food” in early childhood were more likely to be in the top 33% on the SDQ hyperactivity sub-scale at age 7. This may reflect a long-term nutritional imbalance, or differences in parenting style. This finding requires replication before it can provide an avenue for intervention. PMID:18059416

  7. 'Junk food' diet and childhood behavioural problems: results from the ALSPAC cohort.

    Science.gov (United States)

    Wiles, N J; Northstone, K; Emmett, P; Lewis, G

    2009-04-01

    To determine whether a 'junk food' diet at age 4(1/2) is associated with behavioural problems at age 7. Data on approximately 4000 children participating in the Avon Longitudinal Study of Parents and Children, a birth cohort recruited in Avon, UK in 1991/92 were used. Behavioural problems were measured at age 7 using the Strengths and Difficulties Questionnaire (SDQ; maternal completion). Total difficulties and scores for the five sub-scales (hyperactivity, conduct and peer problems, emotional symptoms and pro-social behaviour) were calculated. Principal components analysis of dietary data (frequency of consumption of 57 foods/drinks) collected at age 4(1/2) by maternal report was used to generate a 'junk food' factor. Data on confounders were available from questionnaires. A one standard deviation increase in 'junk food' intake at age 4(1/2) years was associated with increased hyperactivity at age 7 (odds ratio: 1.19; 95% confidence interval: 1.10, 1.29). This persisted after adjustment for confounders including intelligence quotient score (odds ratio: 1.13; 95% confidence interval: 1.01, 1.15). There was little evidence to support an association between 'junk food' intake and overall behavioural difficulties or other sub-scales of the SDQ. Children eating a diet high in 'junk food' in early childhood were more likely to be in the top 33% on the SDQ hyperactivity sub-scale at age 7. This may reflect a long-term nutritional imbalance, or differences in parenting style. This finding requires replication before it can provide an avenue for intervention.

  8. Fatty acid analysis of Iranian junk food, dairy, and bakery products: Special attention to trans-fats

    National Research Council Canada - National Science Library

    Nazari, Bahar; Asgary, Sedigheh; Azadbakht, Leila

    2012-01-01

    Low attention to dairy product consumptions and high intake of junk foods and bakery products might be related to high prevalence of chronic diseases because of their fat content and fatty acid composition...

  9. State policies targeting junk food in schools: racial/ethnic differences in the effect of policy change on soda consumption

    National Research Council Canada - National Science Library

    Taber, Daniel R; Stevens, June; Evenson, Kelly R; Ward, Dianne S; Poole, Charles; Maciejewski, Matthew L; Murray, David M; Brownson, Ross C

    2011-01-01

    ...) percentile, overall and by race/ethnicity. We obtained data on whether states required or recommended that schools prohibit junk food in vending machines, snack bars, concession stands, and parties from the 2000 and 2006 School Health...

  10. A Maternal “Junk Food” Diet in Pregnancy and Lactation Promotes Nonalcoholic Fatty Liver Disease in Rat Offspring

    OpenAIRE

    Bayol, Stéphanie A; Simbi, Bigboy H.; Fowkes, Robert C.; Stickland, Neil C.

    2010-01-01

    With rising obesity rates, nonalcoholic fatty liver disease is predicted to become the main cause of chronic liver disease in the next decades. Rising obesity prevalence is attributed to changes in dietary habits with increased consumption of palatable junk foods, but maternal malnutrition also contributes to obesity in progeny. This study examines whether a maternal junk food diet predisposes offspring to nonalcoholic fatty liver disease. The 144 rat offspring were fed either a balanced chow...

  11. JUNK FOOD ASSOCIATION WITH THE MORPHOLOGICAL CHANGES OF GASTRITIS-A CROSS-SECTIONAL STUDY AMONG RURAL CHILDREN OF MELMARUVATHUR

    OpenAIRE

    Sumathi S.; Padma K

    2016-01-01

    BACKGROUND AND AIM Junk food consumption is common among children that have much adverse effect on the growth of the children and health. This study is aimed to assess the correlation of frequency of junk food intake with the morphological changes of gastric antral biopsies in dyspeptic children. MATERIALS AND METHODS This cross-sectional observational study was carried out in Melmaruvathur Medical College Hospital, Melmaruvathur, during the year 2014-2015. The participants ...

  12. JUNK FOOD ASSOCIATION WITH THE MORPHOLOGICAL CHANGES OF GASTRITIS-A CROSS-SECTIONAL STUDY AMONG RURAL CHILDREN OF MELMARUVATHUR

    Directory of Open Access Journals (Sweden)

    Sumathi S

    2016-09-01

    Full Text Available BACKGROUND AND AIM Junk food consumption is common among children that have much adverse effect on the growth of the children and health. This study is aimed to assess the correlation of frequency of junk food intake with the morphological changes of gastric antral biopsies in dyspeptic children. MATERIALS AND METHODS This cross-sectional observational study was carried out in Melmaruvathur Medical College Hospital, Melmaruvathur, during the year 2014-2015. The participants were dyspeptic children between 10-15 years of age. They were interviewed using various junk food frequency questionnaires and antral biopsy was taken for histopathological assessment. The morphological changes of gastric antral biopsies were recorded and their association with junk food was analysed. RESULTS Out of 37 children studied, the predominant age group affected were between 5-10 years (56.8% with female predominance (67%. Among the frequency, daily usage of junk food constitutes 57% of cases and the remaining 43% were taking intermittently. Biscuits, chocolates, packed chips were regularly used by daily user and bottled drinks, ice cream were used intermittently. Morphological assessment of gastritis showed significant association of junk food intake with increased intensity of mononuclear cell infiltration with a P value of 0.05, presence of Helicobacter pylori with a P value of 0.02 and presence of regenerative atypical changes with a P value of 0.006. CONCLUSION There is a significant association between the junk food intake and the severity of gastritis. The intensity of inflammatory changes, regenerative atypical glands and Helicobacter pylori presence and load were more among those having the habit of daily junk food intake than those taking intermittently.

  13. JUNK FOOD ASSOCIATION WITH THE MORPHOLOGICAL CHANGES OF GASTRITIS-A CROSS-SECTIONAL STUDY AMONG RURAL CHILDREN OF MELMARUVATHUR

    OpenAIRE

    Sumathi S; Padma K

    2016-01-01

    BACKGROUND AND AIM Junk food consumption is common among children that have much adverse effect on the growth of the children and health. This study is aimed to assess the correlation of frequency of junk food intake with the morphological changes of gastric antral biopsies in dyspeptic children. MATERIALS AND METHODS This cross-sectional observational study was carried out in Melmaruvathur Medical College Hospital, Melmaruvathur, during the year 2014-2015. The participants ...

  14. Junk Food Consumption and Effects on Growth Status among Children Aged 6-24 Months in Mashhad, Northeastern Iran

    Directory of Open Access Journals (Sweden)

    Rahim Vakili

    2015-08-01

    Full Text Available Introduction Junk food, due to the lack of vitamins, minerals and trace amounts of energy and protein, there is the risk that the child's stomach filled and by reducing her/his appetite, reduce the chance of nutritious foods. So it is necessary to determine the relationship between using of junk food with growth rate in children. Materials and Methods This cross-sectional descriptive-analytic study was conducted on 300 mothers and their babies , who were referring to 10 selected Mashhad health-care centers for monitoring their 6-24 months children. Participants were selected by cluster and simple random sampling and valid and reliable   questionnaire was used to collect data. Data were analyzed by descriptive- analytic statistics and using SPSS version 16. Results In growth chart, 86.7 percent of children showed appropriate growth, 10.3 percent had delayed growth and 3 percent had horizontal growth curve. In 11.3 percent of families, the junk food has been used for children regularly, 44.7 percent did not believe in these snacks and 44 percent of mothers sometimes used this junk food for their children. Results showed the statistical correlation between junk food consumption and  growth status of children was significant, so children whom haven’t had junk food, have grown more favorable than the other kids (P

  15. A maternal "junk-food" diet reduces sensitivity to the opioid antagonist naloxone in offspring postweaning.

    Science.gov (United States)

    Gugusheff, Jessica R; Ong, Zhi Yi; Muhlhausler, Beverly S

    2013-03-01

    Perinatal exposure to a maternal "junk-food" diet has been demonstrated to increase the preference for palatable diets in adult offspring. We aimed to determine whether this increased preference could be attributed to changes in μ-opioid receptor expression within the mesolimbic reward pathway. We report here that mRNA expression of the μ-opioid receptor in the ventral tegmental area (VTA) at weaning was 1.4-fold (males) and 1.9-fold (females) lower in offspring of junk-food (JF)-fed rat dams than in offspring of dams fed a standard rodent diet (control) (Pfat intake in control offspring (males: 7.7 ± 0.7 vs. 5.4 ± 0.6 g/kg/d; females: 6.9 ± 0.3 vs. 3.9 ± 0.5 g/kg/d; Pfat intake in JF females (42.2 ± 6.0 vs. 23.1 ± 4.1% reduction, Pfood diet results in early desensitization of the opioid system which may explain the increased preference for junk food in these offspring.

  16. Association between energy drink intake, sleep, stress, and suicidality in Korean adolescents: energy drink use in isolation or in combination with junk food consumption

    National Research Council Canada - National Science Library

    Park, Subin; Lee, Yeeun; Lee, Junghyun H

    2016-01-01

    .... This study aimed to investigate the associations between energy drink intake and mental health problems, in isolation or in combination with junk food consumption, in a nationally representative...

  17. A maternal "junk food" diet in pregnancy and lactation promotes nonalcoholic Fatty liver disease in rat offspring.

    Science.gov (United States)

    Bayol, Stéphanie A; Simbi, Bigboy H; Fowkes, Robert C; Stickland, Neil C

    2010-04-01

    With rising obesity rates, nonalcoholic fatty liver disease is predicted to become the main cause of chronic liver disease in the next decades. Rising obesity prevalence is attributed to changes in dietary habits with increased consumption of palatable junk foods, but maternal malnutrition also contributes to obesity in progeny. This study examines whether a maternal junk food diet predisposes offspring to nonalcoholic fatty liver disease. The 144 rat offspring were fed either a balanced chow diet alone or with palatable junk foods rich in energy, fat, sugar, and/or salt during gestation, lactation, and/or after weaning up to the end of adolescence. Offspring fed junk food throughout the study exhibited exacerbated hepatic steatosis, hepatocyte ballooning, and oxidative stress response compared with offspring given free access to junk food after weaning only. These offspring also displayed sex differences in their hepatic molecular metabolic adaptation to diet-induced obesity with increased expression of genes associated with insulin sensitivity, de novo lipogenesis, lipid oxidation, and antiinflammatory properties in males, whereas the gene expression profile in females was indicative of hepatic insulin resistance. Hepatic inflammation and fibrosis were not detected indicating that offspring had not developed severe steatohepatitis by the end of adolescence. Hepatic steatosis and increased oxidative stress response also occurred in offspring born to junk food-fed mothers switched to a balanced chow diet from weaning, highlighting a degree of irreversibility. This study shows that a maternal junk food diet in pregnancy and lactation contributes to the development of nonalcoholic fatty liver disease in offspring.

  18. A Maternal “Junk Food” Diet in Pregnancy and Lactation Promotes Nonalcoholic Fatty Liver Disease in Rat Offspring

    Science.gov (United States)

    Bayol, Stéphanie A.; Simbi, Bigboy H.; Fowkes, Robert C.; Stickland, Neil C.

    2010-01-01

    With rising obesity rates, nonalcoholic fatty liver disease is predicted to become the main cause of chronic liver disease in the next decades. Rising obesity prevalence is attributed to changes in dietary habits with increased consumption of palatable junk foods, but maternal malnutrition also contributes to obesity in progeny. This study examines whether a maternal junk food diet predisposes offspring to nonalcoholic fatty liver disease. The 144 rat offspring were fed either a balanced chow diet alone or with palatable junk foods rich in energy, fat, sugar, and/or salt during gestation, lactation, and/or after weaning up to the end of adolescence. Offspring fed junk food throughout the study exhibited exacerbated hepatic steatosis, hepatocyte ballooning, and oxidative stress response compared with offspring given free access to junk food after weaning only. These offspring also displayed sex differences in their hepatic molecular metabolic adaptation to diet-induced obesity with increased expression of genes associated with insulin sensitivity, de novo lipogenesis, lipid oxidation, and antiinflammatory properties in males, whereas the gene expression profile in females was indicative of hepatic insulin resistance. Hepatic inflammation and fibrosis were not detected indicating that offspring had not developed severe steatohepatitis by the end of adolescence. Hepatic steatosis and increased oxidative stress response also occurred in offspring born to junk food-fed mothers switched to a balanced chow diet from weaning, highlighting a degree of irreversibility. This study shows that a maternal junk food diet in pregnancy and lactation contributes to the development of nonalcoholic fatty liver disease in offspring. PMID:20207831

  19. Offspring from mothers fed a 'junk food' diet in pregnancy and lactation exhibit exacerbated adiposity that is more pronounced in females.

    Science.gov (United States)

    Bayol, S A; Simbi, B H; Bertrand, J A; Stickland, N C

    2008-07-01

    We have shown previously that a maternal junk food diet during pregnancy and lactation plays a role in predisposing offspring to obesity. Here we show that rat offspring born to mothers fed the same junk food diet rich in fat, sugar and salt develop exacerbated adiposity accompanied by raised circulating glucose, insulin, triglyceride and/or cholesterol by the end of adolescence (10 weeks postpartum) compared with offspring also given free access to junk food from weaning but whose mothers were exclusively fed a balanced chow diet in pregnancy and lactation. Results also showed that offspring from mothers fed the junk food diet in pregnancy and lactation, and which were then switched to a balanced chow diet from weaning, exhibited increased perirenal fat pad mass relative to body weight and adipocyte hypertrophy compared with offspring which were never exposed to the junk food diet. This study shows that the increased adiposity was more enhanced in female than male offspring and gene expression analyses showed raised insulin-like growth factor-1 (IGF-1), insulin receptor substrate (IRS)-1, vascular endothelial growth factor (VEGF)-A, peroxisome proliferator-activated receptor-gamma (PPARgamma), leptin, adiponectin, adipsin, lipoprotein lipase (LPL), Glut 1, Glut 3, but not Glut 4 mRNA expression in females fed the junk food diet throughout the study compared with females never given access to junk food. Changes in gene expression were not as marked in male offspring with only IRS-1, VEGF-A, Glut 4 and LPL being up-regulated in those fed the junk food diet throughout the study compared with males never given access to junk food. This study therefore shows that a maternal junk food diet promotes adiposity in offspring and the earlier onset of hyperglycemia, hyperinsulinemia and/or hyperlipidemia. Male and female offspring also display a different metabolic, cellular and molecular response to junk-food-diet-induced adiposity.

  20. Offspring from mothers fed a ‘junk food’ diet in pregnancy and lactation exhibit exacerbated adiposity that is more pronounced in females

    Science.gov (United States)

    Bayol, S A; Simbi, B H; Bertrand, J A; Stickland, N C

    2008-01-01

    We have shown previously that a maternal junk food diet during pregnancy and lactation plays a role in predisposing offspring to obesity. Here we show that rat offspring born to mothers fed the same junk food diet rich in fat, sugar and salt develop exacerbated adiposity accompanied by raised circulating glucose, insulin, triglyceride and/or cholesterol by the end of adolescence (10 weeks postpartum) compared with offspring also given free access to junk food from weaning but whose mothers were exclusively fed a balanced chow diet in pregnancy and lactation. Results also showed that offspring from mothers fed the junk food diet in pregnancy and lactation, and which were then switched to a balanced chow diet from weaning, exhibited increased perirenal fat pad mass relative to body weight and adipocyte hypertrophy compared with offspring which were never exposed to the junk food diet. This study shows that the increased adiposity was more enhanced in female than male offspring and gene expression analyses showed raised insulin-like growth factor-1 (IGF-1), insulin receptor substrate (IRS)-1, vascular endothelial growth factor (VEGF)-A, peroxisome proliferator-activated receptor-γ (PPARγ), leptin, adiponectin, adipsin, lipoprotein lipase (LPL), Glut 1, Glut 3, but not Glut 4 mRNA expression in females fed the junk food diet throughout the study compared with females never given access to junk food. Changes in gene expression were not as marked in male offspring with only IRS-1, VEGF-A, Glut 4 and LPL being up-regulated in those fed the junk food diet throughout the study compared with males never given access to junk food. This study therefore shows that a maternal junk food diet promotes adiposity in offspring and the earlier onset of hyperglycemia, hyperinsulinemia and/or hyperlipidemia. Male and female offspring also display a different metabolic, cellular and molecular response to junk-food-diet-induced adiposity. PMID:18467362

  1. Fatty acid analysis of Iranian junk food, dairy, and bakery products: Special attention to trans-fats

    Directory of Open Access Journals (Sweden)

    Bahar Nazari

    2012-01-01

    Full Text Available Background: Low attention to dairy product consumptions and high intake of junk foods and bakery products might be related to high prevalence of chronic diseases because of their fat content and fatty acid composition. Objective: In this study we investigated the kind and amount of fatty acid content in Iranian junk foods, dairy, and bakery products Materials and Methods: Some common brands of Iranian′s junk foods, dairy, and bakery products were chosen randomly from different supermarkets in Iran. The amount of 10 g sample was considered for fatty acid analysis by gas chromatography equipment with flam ionization detector. Results: In this study stearic acid (C18:0 and palmitic (C16:0 acid have the highest amount among other saturated fatty acids in all groups. In junk foods and bakery products, the most common trans-fatty acid (TFA is elaidic acid (C18:1 9t with ranging from 2.4% to 18.5% and in dairy products vaccinic acid (C18:1 11t has the high level of TFAs among others (2.1% to 11.5%. Conclusion: The amount of TFAs in Iranian junk foods and bakery products was in a high level.

  2. Fatty acid analysis of Iranian junk food, dairy, and bakery products: Special attention to trans-fats.

    Science.gov (United States)

    Nazari, Bahar; Asgary, Sedigheh; Azadbakht, Leila

    2012-10-01

    Low attention to dairy product consumptions and high intake of junk foods and bakery products might be related to high prevalence of chronic diseases because of their fat content and fatty acid composition. In this study we investigated the kind and amount of fatty acid content in Iranian junk foods, dairy, and bakery products. Some common brands of Iranian's junk foods, dairy, and bakery products were chosen randomly from different supermarkets in Iran. The amount of 10 g sample was considered for fatty acid analysis by gas chromatography equipment with flam ionization detector. In this study stearic acid (C18:0) and palmitic (C16:0) acid have the highest amount among other saturated fatty acids in all groups. In junk foods and bakery products, the most common trans-fatty acid (TFA) is elaidic acid (C18:1 9t) with ranging from 2.4% to 18.5% and in dairy products vaccinic acid (C18:1 11t) has the high level of TFAs among others (2.1% to 11.5%). The amount of TFAs in Iranian junk foods and bakery products was in a high level.

  3. "Nutritional Wastelands": Vending Machines, Fast Food Outlets, and the Fight over Junk Food in Canadian Schools.

    Science.gov (United States)

    Gidney, Catherine

    2015-01-01

    In light of a growing obesity crisis among children and concern about junk food in schools, this article investigates the attempt by food and beverage companies to gain entry into Canadian schools. Focusing in particular on the introduction of fast-food franchises in cafeterias and on school boards' secret exclusivity deals with soft drink manufacturers in the 1990s, it examines how and why this process occurred, public reactions to it, and government responses. Placing this phenomenon within a larger pattern of commercialization in North American schools, it argues that long-lasting reforms require government intervention and enforcement.

  4. Microbial diversity and prevalence of foodborne pathogens in cheap and junk foods consumed by primary schoolchildren.

    Science.gov (United States)

    Kim, M J; Kim, S A; Kang, Y S; Hwang, I G; Rhee, M S

    2013-07-01

    Aerobic plate counts (APC), coliforms, Bacillus cereus, Escherichia coli and eight foodborne pathogens were tested in 1008 cheap and junk foods, including candies, dried cakes, chewing gum, chocolate, dried and seasoned seafood, ice cream, and sugary foods. APCs were positive for 342 samples (33·9%), and the majority of the counts were 2-3 log CFU g(-1) or ml(-1) (average: 1·10 log CFU g(-1) or ml(-1) ). Most samples (97·3%) contained no coliforms (average: 0·07 log CFU g(-1) or ml(-1) ). Bacillus cereus was detected in 68 samples (average: 0·14 log CFU g(-1) or ml(-1) ). Escherichia coli and Listeria monocytogenes were detected in 6 and 1 samples, respectively, whereas other foodborne pathogens were not isolated. The highest bacterial counts were associated with dried and seasoned seafood products and dried cakes, suggesting that appropriate regulations of these food types should be considered. Cheap and junk foods were produced mainly in developing countries, but there were no significant differences in the bacterial counts among different countries of origin. The presence of foodborne pathogens may pose a risk for children. These results suggest that there is cause for deeper concern about the safety of these foods and that effective countermeasures should be established to improve their microbiological safety. Food safety is especially important for children, but only limited information is available about the microbiological quality of cheap and junk foods that are consumed frequently by primary schoolchildren (e.g. dried cakes, candies and chocolates). The present study investigated the microbial quality of cheap and junk foods, and our results indicate that these foods are a potential health risk for children, therefore, deeper concern about the safety of these foods and effective countermeasures should be established to improve their microbiological safety. The present study may contribute to the development of an appropriate child food

  5. Evidence that a maternal "junk food" diet during pregnancy and lactation can reduce muscle force in offspring.

    Science.gov (United States)

    Bayol, Stéphanie A; Macharia, Raymond; Farrington, Samantha J; Simbi, Bigboy H; Stickland, Neil C

    2009-02-01

    Obesity is a multi-factorial condition generally attributed to an unbalanced diet and lack of exercise. Recent evidence suggests that maternal malnutrition during pregnancy and lactation can also contribute to the development of obesity in offspring. We have developed an animal model in rats to examine the effects of maternal overeating on a westernized "junk food" diet using palatable processed foods rich in fat, sugar and salt designed for human consumption. Using this model, we have shown that such a maternal diet can promote overeating and a greater preference for junk food in offspring at the end of adolescence. The maternal junk food diet also promoted adiposity and muscle atrophy at weaning. Impaired muscle development may permanently affect the function of this tissue including its ability to generate force. The aim of this study is to determine whether a maternal junk food diet can impair muscle force generation in offspring. Twitch and tetanic tensions were measured in offspring fed either chow alone (C) or with a junk food diet (J) during gestation, lactation and/or post-weaning up to the end of adolescence such that three groups of offspring were used, namely the CCC, JJC and JJJ groups. We show that adult offspring from mothers fed the junk food diet in pregnancy and lactation display reduced muscle force (both specific twitch and tetanic tensions) regardless of the post-weaning diet compared with offspring from mothers fed a balanced diet. Maternal malnutrition can influence muscle force production in offspring which may affect an individual's ability to exercise and thereby combat obesity.

  6. Maternal "junk food" diet during pregnancy as a predictor of high birthweight: findings from the healthy beginnings trial.

    Science.gov (United States)

    Wen, Li Ming; Simpson, Judy M; Rissel, Chris; Baur, Louise A

    2013-03-01

    A high infant birthweight is associated with future risk of a range of adverse health consequences. This study sought to determine whether maternal "junk food" diet (energy-dense, nutrient-poor) predicts high birthweight in first-time mothers in southwest Sydney, Australia. A community-based longitudinal study was conducted with a total of 368 first-time mothers and their newborns. Information about maternal "junk food" diet, including high consumption of soft drink, fast food, and/or processed meat and chips, and self-reported prepregnant weight and height of first-time mothers was collected by a face-to-face interview with mothers between 24 and 34 weeks of pregnancy. Birthweight was measured in hospital and reported by the mother, together with gestational age, when the baby was 6 months old. Logistic regression modeling was used to determine the factors predicting birthweight greater than 4.0 kg. Eleven percent of newborns weighed more than 4.0 kg (12% boys, 9% girls). Compared with mothers who had a "junk food" diet, mothers who had not consumed "junk food" during pregnancy were significantly less likely to have a newborn weighing more than 4.0 kg, with adjusted odds ratio (AOR) 0.36, 95 percent confidence interval (CI) 0.14-0.91, p = 0.03, after adjusting for maternal weight status and gestational age. Compared with healthy and underweight mothers, overweight or obese mothers were more likely to have a newborn weighing more than 4.0 kg (AOR overweight 3.03, 95% CI 1.35-6.80; obese 3.79, 95% CI 1.41-10.25) after allowing for "junk food" diet and gestational age. Maternal "junk food" diet during pregnancy and prepregnant overweight and obesity were independent predictors of high infant birthweight. Early childhood obesity interventions should consider addressing these factors. © 2013, Copyright the Authors Journal compilation © 2013, Wiley Periodicals, Inc.

  7. Junk Food Consumption and Effects on Growth Status among Children Aged 6-24 Months in Mashhad, Northeastern Iran

    OpenAIRE

    Rahim Vakili; Mohammad Ali Kiani; Masumeh Saeidi; Bibi Leila Hoseini; Mansoure Alipour Anbarani

    2015-01-01

    Introduction Junk food, due to the lack of vitamins, minerals and trace amounts of energy and protein, there is the risk that the child's stomach filled and by reducing her/his appetite, reduce the chance of nutritious foods. So it is necessary to determine the relationship between using of junk food with growth rate in children. Materials and Methods This cross-sectional descriptive-analytic study was conducted on 300 mothers and their babies , who were referring to 10 selected Mashhad healt...

  8. JUNK FOOD CONSUMPTION PATTERN AND OBESITY AMONG SCHOOL GOING CHILDREN IN AN URBAN FIELD PRACTICE AREA: A CROSS SECTIONAL STUDY

    Directory of Open Access Journals (Sweden)

    Vidya

    2015-03-01

    Full Text Available BACKGROUND: Junk food simply means an empty calorie food; it lacks in micronutrients such as vitamins, minerals, or amino acids, and fibre but has high energy (calories. During school - age years, children begin to establish habits for eating and exercise that stick w ith them for their entire lives. If children establish healthy habits, their risk for developing many chronic diseases will be greatly decreased. The family, friends, schools, and community resources in a child’s environment reinforce lifestyle habits rega rding diet and activity. OBJECTIVES: To study the fast food consumptions pattern and fast food preferences among the school going children (9 - 13yrs and some of the determinants related to fast food consumption . STUDY SETTING: Department of Community Medic ine in an Urban field practice area of Rajarajeswari Medical College & Hospital, Bangalore. STUDY DESIGN: Cross - sectional study. STUDY DURATION: Three months duration ( Oct – Dec 2014. STUDY POPULATION: school students studying in V th standard to X th standar d. SAMPLE SIZE : The selected school had a strength of 200 students. Hence complete enumeration of the students was considered for this study. DATA COLLECTION : by using pre - structured questionnaire by interview method. The variables included were socio - demographic profile, measurement of height, weight and questions related to junk food consumption and its patterns. DATA ANALYSIS: using statistics software SPSS 20. Mean and standard deviation was calculated for anthropometric measurements. Test of significance for proportions was done by Chi - square test. RESULTS: Among 200 study subjects, 107 were male (53.5% and 93 females (46.5%. Majority of the students wer e in the age group of 12 - 15 years ( 66% and 9 - 11 years ( 34%. Snacks (41%, Fast food (25.50%, soft drinks (17.50% and candies (16% were the favourite junk foods among the study subjects. Taste and time factors, watching television while consuming

  9. Naming 'junk': Human non-protein coding RNA (ncRNA gene nomenclature

    Directory of Open Access Journals (Sweden)

    Wright Mathew W

    2011-01-01

    Full Text Available Abstract Previously, the majority of the human genome was thought to be 'junk' DNA with no functional purpose. Over the past decade, the field of RNA research has rapidly expanded, with a concomitant increase in the number of non-protein coding RNA (ncRNA genes identified in this 'junk'. Many of the encoded ncRNAs have already been shown to be essential for a variety of vital functions, and this wealth of annotated human ncRNAs requires standardised naming in order to aid effective communication. The HUGO Gene Nomenclature Committee (HGNC is the only organisation authorised to assign standardised nomenclature to human genes. Of the 30,000 approved gene symbols currently listed in the HGNC database (http://www.genenames.org/search, the majority represent protein-coding genes; however, they also include pseudogenes, phenotypic loci and some genomic features. In recent years the list has also increased to include almost 3,000 named human ncRNA genes. HGNC is actively engaging with the RNA research community in order to provide unique symbols and names for each sequence that encodes an ncRNA. Most of the classical small ncRNA genes have now been provided with a unique nomenclature, and work on naming the long (> 200 nucleotides non-coding RNAs (lncRNAs is ongoing.

  10. The effects of television advertisements for junk food versus nutritious food on children's food attitudes and preferences.

    Science.gov (United States)

    Dixon, Helen G; Scully, Maree L; Wakefield, Melanie A; White, Victoria M; Crawford, David A

    2007-10-01

    Television (TV) food advertising has attracted criticism for its potential role in promoting unhealthy dietary practices among children. Content analyses indicate junk food advertising is prevalent on Australian children's TV; healthy eating is rarely promoted. This paper presents (a) a cross-sectional survey examining associations between children's regular TV viewing habits and their food-related attitudes and behaviour; and (b) an experiment assessing the impact of varying combinations of TV advertisements (ads) for unhealthy and healthy foods on children's dietary knowledge, attitudes and intentions. The experimental conditions simulated possible models for regulating food ads on children's TV. Participants were 919 grade five and six students from schools in Melbourne, Australia. The survey showed that heavier TV use and more frequent commercial TV viewing were independently associated with more positive attitudes toward junk food; heavier TV use was also independently associated with higher reported junk food consumption. The experiment found that ads for nutritious foods promote selected positive attitudes and beliefs concerning these foods. Findings are discussed in light of methodological issues in media effects research and their implications for policy and practice. It is concluded that changing the food advertising environment on children's TV to one where nutritious foods are promoted and junk foods are relatively unrepresented would help to normalize and reinforce healthy eating.

  11. Identification of junk buyers' contribution to recycling of household waste in Hanoi, Vietnam, through a physical composition analysis.

    Science.gov (United States)

    Kawai, Kosuke; Osako, Masahiro; Matsui, Saburo; Dong, Nguyen The

    2012-07-01

    Even in developing countries, the amount of containers and packaging waste are increasing in line with population concentration and lifestyle changes in urban areas. This can cause serious problems for the disposal of municipal solid waste. Through a physical composition analysis of household waste in Hanoi, the capital of Vietnam, this study aimed to identify the contribution made by junk buyers to recycling. Interviews on the handling of recyclable waste by households were conducted. About 232 kg of recyclable waste was sampled from a total of 115 households, and about 230 kg of municipal solid waste was sampled from a total of 101 households and sorted into 69 categories for measurement by volume and weight. The interview survey revealed that a high proportion of households tended to routinely store recyclable waste for sale or donation to junk buyers. Junk buyers accounted for 8.8% of recycling by weight or 26.0% by volume according to the results of the physical composition analysis. In addition, the results suggested that containers and packaging waste accounted for the largest proportion of household waste by volume. Junk buyers recycled 25.5% by weight of containers and packaging waste. In the formulation of new plans for municipal solid waste management to improve the current situation and handle future challenges, the role of the informal sector should be monitored carefully and reliable data on recyclable waste should be collected continuously.

  12. Radiological control of the junk exports in Cuba; Control radiologico de las exportaciones de chatarra en Cuba

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez L, O.; Capote F, E.; Carrazana G, J.A.; Zerquera, J.T.; Ramos V, O.; Alonso A, D.; Fernandez, I.M.; Caveda R, C.A.; Madrazo M, S.; Barroso P, I. [CPHR, Calle 20 No. 4113 e/41 y 47, Playa, C.P. 11300, A.P. 6195, C.P. 10600 La Habana (Cuba)]. e-mail: orlando@cphr.edu.cu

    2006-07-01

    Even when in Cuba a strict control exists on the radiation sources that enter to the country to be used in the different applications, it can be given the case that sources or contaminated materials that never were under this control due fundamentally to that entered to the country before the same one existed, appear in the junk that is marketed. In our country it is effective the Combined Resolution CITMA-MINCEX dated on April, 2002 that settles down the necessity and obligation that has all that manipulates, imports, exports or process junk of carrying out it a radiological control. From April, 2002 making use of a minimum of resources, an own methodology, a properly qualified personnel and the support of a credited laboratory by the ISO 17025 standard, the radioactivity measurement service in junk belonging to the Center of Protection and Hygiene of the Radiations (CPHR), it has reduced the risks that sources or contaminated materials are found in the junk that is exported in the main exporter companies of this line in Cuba avoiding possible radiological emergency situations that affect the population and the environment. (Author)

  13. State but not district nutrition policies are associated with less junk food in vending machines and school stores in US public schools.

    Science.gov (United States)

    Kubik, Martha Y; Wall, Melanie; Shen, Lijuan; Nanney, Marilyn S; Nelson, Toben F; Laska, Melissa N; Story, Mary

    2010-07-01

    Policy that targets the school food environment has been advanced as one way to increase the availability of healthy food at schools and healthy food choice by students. Although both state- and district-level policy initiatives have focused on school nutrition standards, it remains to be seen whether these policies translate into healthy food practices at the school level, where student behavior will be impacted. To examine whether state- and district-level nutrition policies addressing junk food in school vending machines and school stores were associated with less junk food in school vending machines and school stores. Junk food was defined as foods and beverages with low nutrient density that provide calories primarily through fats and added sugars. A cross-sectional study design was used to assess self-report data collected by computer-assisted telephone interviews or self-administered mail questionnaires from state-, district-, and school-level respondents participating in the School Health Policies and Programs Study 2006. The School Health Policies and Programs Study, administered every 6 years since 1994 by the Centers for Disease Control and Prevention, is considered the largest, most comprehensive assessment of school health policies and programs in the United States. A nationally representative sample (n=563) of public elementary, middle, and high schools was studied. Logistic regression adjusted for school characteristics, sampling weights, and clustering was used to analyze data. Policies were assessed for strength (required, recommended, neither required nor recommended prohibiting junk food) and whether strength was similar for school vending machines and school stores. School vending machines and school stores were more prevalent in high schools (93%) than middle (84%) and elementary (30%) schools. For state policies, elementary schools that required prohibiting junk food in school vending machines and school stores offered less junk food than

  14. Assessment of the Situation and the Cause of Junk Food Consumption in Iran and Recommendation of Interventions for Reducing its Consumption

    OpenAIRE

    Behzad Damari; Sahand Riazi-Isfahani; Maryam Hajian; Arezoo Rezazadeh

    2016-01-01

    Background and Objective: The consumption of junk food in Iran is alarmingly increasing. This study aimed to determine the influencing factors of junk food consumption and amendable interventions for decreasing  the consumption.Materials and Methods: In this qualitative study, Valid documentations were collected by searching the database using related key words and the key points were imported in a checklist and after identifying and prioritizing stakeholders through stakeholder analysis meth...

  15. JUNK FOOD CONSUMPTION PATTERN AND OBESITY AMONG SCHOOL GOING CHILDREN IN AN URBAN FIELD PRACTICE AREA: A CROSS SECTIONAL STUDY

    OpenAIRE

    Vidya; Damayanthi; Sharada; Shashikala

    2015-01-01

    BACKGROUND: Junk food simply means an empty calorie food; it lacks in micronutrients such as vitamins, minerals, or amino acids, and fibre but has high energy (calories). During school - age years, children begin to establish habits for eating and exercise that stick w ith them for their entire lives. If children establish healthy habits, their risk for developing many chronic diseases will be greatly decreased. The family, friends, ...

  16. JUNK FOOD CONSUMPTION PATTERN AND OBESITY AMONG SCHOOL GOING CHILDREN IN AN URBAN FIELD PRACTICE AREA: A CROSS SECTIONAL STUDY

    OpenAIRE

    Vidya; Damayanthi; Sharada; Shashikala

    2015-01-01

    BACKGROUND: Junk food simply means an empty calorie food; it lacks in micronutrients such as vitamins, minerals, or amino acids, and fibre but has high energy (calories). During school - age years, children begin to establish habits for eating and exercise that stick w ith them for their entire lives. If children establish healthy habits, their risk for developing many chronic diseases will be greatly decreased. The family, friends, ...

  17. Exploring why junk foods are 'essential' foods and how culturally tailored recommendations improved feeding in Egyptian children.

    Science.gov (United States)

    Kavle, Justine A; Mehanna, Sohair; Saleh, Gulsen; Fouad, Mervat A; Ramzy, Magda; Hamed, Doaa; Hassan, Mohamed; Khan, Ghada; Galloway, Rae

    2015-07-01

    In Egypt, the double burden of malnutrition and rising overweight and obesity in adults mirrors the transition to westernized diets and a growing reliance on energy-dense, low-nutrient foods. This study utilized the trials of improved practices (TIPs) methodology to gain an understanding of the cultural beliefs and perceptions related to feeding practices of infants and young children 0-23 months of age and used this information to work in tandem with 150 mothers to implement feasible solutions to feeding problems in Lower and Upper Egypt. The study triangulated in-depth interviews (IDIs) with mothers participating in TIPs, with IDIs with 40 health providers, 40 fathers and 40 grandmothers to gain an understanding of the influence and importance of the role of other caretakers and health providers in supporting these feeding practices. Study findings reveal high consumption of junk foods among toddlers, increasing in age and peaking at 12-23 months of age. Sponge cakes and sugary biscuits are not perceived as harmful and considered 'ideal' common complementary foods. Junk foods and beverages often compensate for trivial amounts of food given. Mothers are cautious about introducing nutritious foods to young children because of fears of illness and inability to digest food. Although challenges in feeding nutritious foods exist, mothers were able to substitute junk foods with locally available and affordable foods. Future programming should build upon cultural considerations learned in TIPs to address sustainable, meaningful changes in infant and young child feeding to reduce junk foods and increase dietary quality, quantity and frequency.

  18. The Effect of nutrition education on knowledge, attitude, and performance about junk food consumption among students of female primary schools

    OpenAIRE

    Vardanjani, Ali Esmaeili; Reisi, Mahnoush; Javadzade, Homamodin; Pour, Zabihollah Gharli; Tavassoli, Elahe

    2015-01-01

    Background: Undoubtedly, proper nutrition has important role in safeguarding the individual from many diseases, especially chronic ones, and increasing ones physical and intellectual efficiency. Considering the importance of nutrition education to school-age kids, this research was done with the purpose of determining the effect of nutrition education on the knowledge, attitude, and performance of female students at primary school about junk food consumption. Materials and Methods: This is an...

  19. 'Traffic-light' nutrition labelling and 'junk-food' tax: a modelled comparison of cost-effectiveness for obesity prevention.

    Science.gov (United States)

    Sacks, G; Veerman, J L; Moodie, M; Swinburn, B

    2011-07-01

    Cost-effectiveness analyses are important tools in efforts to prioritise interventions for obesity prevention. Modelling facilitates evaluation of multiple scenarios with varying assumptions. This study compares the cost-effectiveness of conservative scenarios for two commonly proposed policy-based interventions: front-of-pack 'traffic-light' nutrition labelling (traffic-light labelling) and a tax on unhealthy foods ('junk-food' tax). For traffic-light labelling, estimates of changes in energy intake were based on an assumed 10% shift in consumption towards healthier options in four food categories (breakfast cereals, pastries, sausages and preprepared meals) in 10% of adults. For the 'junk-food' tax, price elasticities were used to estimate a change in energy intake in response to a 10% price increase in seven food categories (including soft drinks, confectionery and snack foods). Changes in population weight and body mass index by sex were then estimated based on these changes in population energy intake, along with subsequent impacts on disability-adjusted life years (DALYs). Associated resource use was measured and costed using pathway analysis, based on a health sector perspective (with some industry costs included). Costs and health outcomes were discounted at 3%. The cost-effectiveness of each intervention was modelled for the 2003 Australian adult population. Both interventions resulted in reduced mean weight (traffic-light labelling: 1.3 kg (95% uncertainty interval (UI): 1.2; 1.4); 'junk-food' tax: 1.6 kg (95% UI: 1.5; 1.7)); and DALYs averted (traffic-light labelling: 45,100 (95% UI: 37,700; 60,100); 'junk-food' tax: 559,000 (95% UI: 459,500; 676,000)). Cost outlays were AUD81 million (95% UI: 44.7; 108.0) for traffic-light labelling and AUD18 million (95% UI: 14.4; 21.6) for 'junk-food' tax. Cost-effectiveness analysis showed both interventions were 'dominant' (effective and cost-saving). Policy-based population-wide interventions such as traffic

  20. A junk-food hypothesis for gannets feeding on fishery waste

    Science.gov (United States)

    Grémillet, David; Pichegru, Lorien; Kuntz, Grégoire; Woakes, Anthony G; Wilkinson, Sarah; Crawford, Robert J.M; Ryan, Peter G

    2008-01-01

    Worldwide fisheries generate large volumes of fishery waste and it is often assumed that this additional food is beneficial to populations of marine top-predators. We challenge this concept via a detailed study of foraging Cape gannets Morus capensis and of their feeding environment in the Benguela upwelling zone. The natural prey of Cape gannets (pelagic fishes) is depleted and birds now feed extensively on fishery wastes. These are beneficial to non-breeding birds, which show reduced feeding effort and high survival. By contrast, breeding gannets double their diving effort in an attempt to provision their chicks predominantly with high-quality, live pelagic fishes. Owing to a scarcity of this resource, they fail and most chicks die. Our study supports the junk-food hypothesis for Cape gannets since it shows that non-breeding birds can survive when complementing their diet with fishery wastes, but that they struggle to reproduce if live prey is scarce. This is due to the negative impact of low-quality fishery wastes on the growth patterns of gannet chicks. Marine management policies should not assume that fishery waste is generally beneficial to scavenging seabirds and that an abundance of this artificial resource will automatically inflate their populations. PMID:18270155

  1. More apples fewer chips? the effect of school fruit schemes on the consumption of junk food.

    Science.gov (United States)

    Brunello, Giorgio; De Paola, Maria; Labartino, Giovanna

    2014-10-01

    Using Italian data, we evaluate the effects on the consumption of unhealthy snacks of a European Union-wide campaign providing fruit and vegetables to school children and promoting healthy diet habits. We use scanner data of supermarket sales in the city of Rome. Using a difference-in-difference approach, we compare the sales of these snacks before and after the campaign in supermarkets located within a 500 m radius of schools that participated to the program (the treated group) and in supermarkets located outside that radius (control group). We find that the campaign has been effective in reducing the increase in the sales of unhealthy snacks in treated stores - relative to control stores - only in the case of regular stores, which tend to locate in the wealthier areas of Rome. No effect is found, instead, for discount stores, where people with a higher risk of developing obesity are more likely to shop. Our results suggest that the European School Fruit campaign has restrained the consumption of junk food in the sub-group of the population (wealthier families) who is less likely to be exposed to overweight and obesity problems, but has not been effective at all for the sub-group more at risk. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. [Study on factors related to top 10 junk food consumption at 8 to 16 years of age, in Haidian District of Beijing].

    Science.gov (United States)

    Zhu, Shu-ping; Ding, Yue-jiang; Lu, Xiang-feng; Wang, Hong-wei; Yang, Mu; Wang, Jian-xiu; Chao, Xiao-dong; Zhao, Zhen

    2008-08-01

    To study the current situation of ten types of junk food consumption (assessed by World Health Organization) among children and adolescent as well as the contributing factors in Haidian District, Beijing so as to provide evidence for developing preventive and control measures and interventions. A questionnaire survey was conducted to investigate the consumption of ten types of junk food practices in 1019 children and adolescent aged 8-16 years in Beijing Haidian District. One month prior to the study, 97.50% of the children and adolescent had eaten at least one type of junk food and 15.88% of them had eaten all types of them. Rates on having eaten deep fried food, pickled food, processed meat products, biscuits, coke or alike drinks, convenience/fast food, canned food, dried or preserved fruit, cold and sweet food, barbecue food etc. appeared to be 70.43%, 60.14%, 79.72%, 64.24%, 69.63%, 78.72%, 42.16%, 51.95%, 68.13%, 60.14% respectively. The rate on eaten more than once a day of these ten types were 26.95%, 36.88%, 34.84%, 32.97%, 27.40%, 28.18%, 37.91%, 26.15%, 37.39%, 22.10% respectively. The rates for "do not like" and "dislike" these ten types junk food were 10.96%, 27.42%, 7.08%, 12.11%, 6.56%, 6.59%, 17.80%, 13.59%, 3.42%, 5.19% respectively. Most of the children and adolescent ate junk food mainly during breakfast at home. Most of the surveyed children and adolescent did not have correct idea on nutrition of junk food. They received the information of junk food mainly from sources as advertisement on TV (67.95%), mother (9.02%), newspaper or magazines (6.71%). Many factors, such as individual factors (including physiological and psychological situations), social factors, family factors and the characteristics of food contributed to the eating junk food practices of children and adolescent. Eating junk food is a popular event among children and adolescent in Beijing Haidian District. Education strategies on nutrition should be developed and launched in

  3. 'Treats', 'sometimes foods', 'junk': a qualitative study exploring 'extra foods' with parents of young children.

    Science.gov (United States)

    Petrunoff, Nicholas A; Wilkenfeld, Rachel L; King, Lesley A; Flood, Victoria M

    2014-05-01

    The present study investigated parents' understanding and approaches to providing energy-dense and nutrient-poor 'extra foods' to pre-school children and explored variation between parents of low and high socio-economic status in relation to these issues. We conducted thirteen focus groups. Data were subject to framework analysis. Child-care centres in distinctly socially disadvantaged and socially advantaged areas. Eighty-eight parents of children aged 3-5 years. The three most common terms parents identified to describe foods that are not 'everyday foods' were 'treats', 'sometimes foods' and 'junk'. Parents' perceptions regarding what influences them in providing food to their children included seven sub-themes: (i) the influence of the child; (ii) food-related parenting practices; (iii) health considerations; (iv) food costs and convenience; (v) external factors perceived as influencing their child; (vi) factors related to child care; and (vii) social influences and occasions. Parents' decision-making processes regarding provision of 'extra foods' related to moderation and balance. Parents generally expressed the position that as long as a child is eating healthy foods, then treats are appropriate; and for many parents, this might apply frequently. All groups described the health of their child as an influence, but parents in low socio-economic groups were more likely to describe immediate concerns (dental health, behaviour) in relation to avoiding sugar-dense food or drink. The belief that provision of 'extra foods' can be frequent as long as children are eating a healthy balance of foods is factored into parents' decision making. Challenging this belief may be important for reducing the consumption of 'extra foods' by young children.

  4. Children's understanding of the selling versus persuasive intent of junk food advertising: implications for regulation.

    Science.gov (United States)

    Carter, Owen B J; Patterson, Lisa J; Donovan, Robert J; Ewing, Michael T; Roberts, Clare M

    2011-03-01

    Evidence suggests that until 8 years of age most children are cognitively incapable of appreciating the commercial purpose of television advertising and are particularly vulnerable to its persuasive techniques. After this age most children begin to describe the 'selling' intent of advertising and it is widely assumed this equips them with sufficient cognitive defences to protect against advertisers' persuasion attempts. However, much of the previous literature has been criticised for failing to differentiate between children's awareness of 'selling' versus 'persuasive' intent, the latter representing a more sophisticated understanding and superior cognitive defence. Unfortunately there is little literature to suggest at what age awareness of 'persuasive intent' emerges; our aim was to address this important issue. Children (n = 594) were recruited from each grade from Pre-primary (4-5 years) to Grade 7 (11-12 years) from ten primary schools in Perth, Western Australia and exposed to a McDonald's television advertisement. Understanding the purpose of television advertising was assessed both nonverbally (picture indication) and verbally (small discussion groups of 3-4), with particular distinction made between selling versus persuasive intent. Consistent with previous literature, a majority of children described the 'selling' intent of television advertising by 7-8 years both nonverbally and verbally, increasing to 90% by 11-12 years. Awareness of 'persuasive' intent emerged slowly as a function of age but even by our oldest age-group was only 40%. Vulnerability to television advertising may persist until children are far older than previously thought. These findings have important implications regarding the debate surrounding regulation of junk food (and other) advertising aimed at children.

  5. Using GPS and activity tracking to reveal the influence of adolescents' food environment exposure on junk food purchasing.

    Science.gov (United States)

    Sadler, Richard C; Clark, Andrew F; Wilk, Piotr; O'Connor, Colleen; Gilliland, Jason A

    2016-06-09

    This study examines the influence of adolescents' exposure to unhealthy food outlets on junk food purchasing during trips between home and school, with particular attention to how exposure and purchasing differ according to child's biological sex, mode of transportation, and direction to or from school. Between 2010 and 2013, students (n = 654) aged 9-13 years from 25 schools in London and Middlesex County, ON, completed a socio-demographic survey and an activity diary (to identify food purchases), and were observed via a global positioning system for 2 weeks (to track routes for trips to/from school). Spatial data on routes and purchase data were integrated with a validated food outlet database in a geographic information system, and exposure was measured as the minutes a child spent within 50 m of an unhealthy food outlet (i.e., fast food restaurants, variety stores). For trips involving junk food exposure (n = 4588), multilevel logistic regression was used to assess the relationship between exposure and purchasing. Multilevel analyses indicated that adolescents' duration of exposure to unhealthy food outlets between home and school had a significant effect on the likelihood of junk food purchasing. This relationship remained significant when the data were stratified by sex (female/male), trip direction (to/from school) and travel mode (active/car), with the exception of adolescents who travelled by bus. Policies and programs that mitigate the concentration of unhealthy food outlets close to schools are critical for encouraging healthy eating behaviours among children and reducing diet-related health issues such as obesity.

  6. Eating 'Junk-Food' Produces Rapid and Long-Lasting Increases in NAc CP-AMPA Receptors: Implications for Enhanced Cue-Induced Motivation and Food Addiction.

    Science.gov (United States)

    Oginsky, Max F; Goforth, Paulette B; Nobile, Cameron W; Lopez-Santiago, Luis F; Ferrario, Carrie R

    2016-12-01

    Urges to eat are influenced by stimuli in the environment that are associated with food (food cues). Obese people are more sensitive to food cues, reporting stronger craving and consuming larger portions after food cue exposure. The nucleus accumbens (NAc) mediates cue-triggered motivational responses, and activations in the NAc triggered by food cues are stronger in people who are susceptible to obesity. This has led to the idea that alterations in NAc function similar to those underlying drug addiction may contribute to obesity, particularly in obesity-susceptible individuals. Motivational responses are mediated in part by NAc AMPA receptor (AMPAR) transmission, and recent work shows that cue-triggered motivation is enhanced in obesity-susceptible rats after 'junk-food' diet consumption. Therefore, here we determined whether NAc AMPAR expression and function is increased by 'junk-food' diet consumption in obesity-susceptible vs -resistant populations using both outbred and selectively bred models of susceptibility. In addition, cocaine-induced locomotor activity was used as a general 'read out' of mesolimbic function after 'junk-food' consumption. We found a sensitized locomotor response to cocaine in rats that gained weight on a 'junk-food' diet, consistent with greater responsivity of mesolimbic circuits in obesity-susceptible groups. In addition, eating 'junk-food' increased NAc calcium-permeable-AMPAR (CP-AMPAR) function only in obesity-susceptible rats. This increase occurred rapidly, persisted for weeks after 'junk-food' consumption ceased, and preceded the development of obesity. These data are considered in light of enhanced cue-triggered motivation and striatal function in obesity-susceptible rats and the role of NAc CP-AMPARs in enhanced motivation and addiction.

  7. Eating ‘Junk-Food' Produces Rapid and Long-Lasting Increases in NAc CP-AMPA Receptors: Implications for Enhanced Cue-Induced Motivation and Food Addiction

    Science.gov (United States)

    Oginsky, Max F; Goforth, Paulette B; Nobile, Cameron W; Lopez-Santiago, Luis F; Ferrario, Carrie R

    2016-01-01

    Urges to eat are influenced by stimuli in the environment that are associated with food (food cues). Obese people are more sensitive to food cues, reporting stronger craving and consuming larger portions after food cue exposure. The nucleus accumbens (NAc) mediates cue-triggered motivational responses, and activations in the NAc triggered by food cues are stronger in people who are susceptible to obesity. This has led to the idea that alterations in NAc function similar to those underlying drug addiction may contribute to obesity, particularly in obesity-susceptible individuals. Motivational responses are mediated in part by NAc AMPA receptor (AMPAR) transmission, and recent work shows that cue-triggered motivation is enhanced in obesity-susceptible rats after ‘junk-food' diet consumption. Therefore, here we determined whether NAc AMPAR expression and function is increased by ‘junk-food' diet consumption in obesity-susceptible vs -resistant populations using both outbred and selectively bred models of susceptibility. In addition, cocaine-induced locomotor activity was used as a general ‘read out' of mesolimbic function after ‘junk-food' consumption. We found a sensitized locomotor response to cocaine in rats that gained weight on a ‘junk-food' diet, consistent with greater responsivity of mesolimbic circuits in obesity-susceptible groups. In addition, eating ‘junk-food' increased NAc calcium-permeable-AMPAR (CP-AMPAR) function only in obesity-susceptible rats. This increase occurred rapidly, persisted for weeks after ‘junk-food' consumption ceased, and preceded the development of obesity. These data are considered in light of enhanced cue-triggered motivation and striatal function in obesity-susceptible rats and the role of NAc CP-AMPARs in enhanced motivation and addiction. PMID:27383008

  8. Association between junk food consumption and mental health in a national sample of Iranian children and adolescents: the CASPIAN-IV study.

    Science.gov (United States)

    Zahedi, Hoda; Kelishadi, Roya; Heshmat, Ramin; Motlagh, Mohammad Esmaeil; Ranjbar, Shirin Hasani; Ardalan, Gelayol; Payab, Moloud; Chinian, Mohammad; Asayesh, Hamid; Larijani, Bagher; Qorbani, Mostafa

    2014-01-01

    The consumption of high energy and low nutritional content foods, which are known as junk foods, has increased. The aim of this study was to evaluate the association between junk food intake and mental health in a national sample of Iranian children and adolescents. Data were obtained from a surveillance system entitled CASPIAN-IV (Childhood and Adolescence Surveillance and Prevention of Adult Non communicable Disease) study of school students, ages 6 to 18 y in Iran. The students and their parents completed two sets of reliable questionnaires obtained from Global School Health Survey translated to Persian. The student questionnaire comprised several questions such as psychiatric distress (worry, depression, confusion, insomnia, anxiety, aggression, and worthless) and violent behaviors (physical fighting, being a victim, and bullying). The junk foods consisted of sweets, sweetened beverages, fast foods, and salty snacks. In the sample of 13 486 children and adolescents, the frequency of junk food consumption was significantly associated with psychiatric distress (P junk foods (P 0.05). Additionally, the results of logistic regression showed that daily consumption of sweetened beverages and snacks significantly increased the odds of self-reported psychiatric distress. Also, daily consumption of salty snacks was significantly associated with violent behavior, including physical fighting (odds ratio [OR], 1.39; 95% confidence interval [CI], 1.21-1.60), being a victim (OR, 1.19; 95% CI, 1.04-1.37), and bullying (OR, 1.55; 95% CI, 1.32-1.82). Junk food consumption may increase the risk for psychiatric distress and violent behaviors in children and adolescents. Improvement of eating habits toward healthier diets may be an effective approach for improving mental health. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Testing the junk-food hypothesis on marine birds: Effects of prey type on growth and development

    Science.gov (United States)

    Romano, Marc D.; Piatt, J.F.; Roby, D.D.

    2006-01-01

    The junk-food hypothesis attributes declines in productivity of marine birds and mammals to changes in the species of prey they consume and corresponding differences in nutritional quality of those prey. To test this hypothesis nestling Black-legged Kittiwakes (Rissa tridactyla) and Tufted Puffins (Fratercula cirrhata) were raised in captivity under controlled conditions to determine whether the type and quality of fish consumed by young seabirds constrains their growth and development. Some nestlings were fed rations of Capelin (Mallotus villosus), Herring (Clupea pallasi) or Sand Lance (Ammodytes hexapterus) and their growth was compared with nestlings raised on equal biomass rations of Walleye Pollock (Theragra chalcograma). Nestlings fed rations of herring, sand lance, or capelin experienced higher growth increments than nestlings fed pollock. The energy density of forage fish fed to nestlings had a marked effect on growth increments and could be expected to have an effect on pre- and post-fledging survival of nestlings in the wild. These results provide empirical support for the junk-food hypothesis.

  10. Persuading people to eat less junk food: a cognitive resource match between attitudinal ambivalence and health message framing.

    Science.gov (United States)

    Yan, Changmin

    2015-01-01

    This study investigated the interactive effects of attitudinal ambivalence and health message framing on persuading people to eat less junk food. Within the heuristic-systematic model of information processing, an attitudinal ambivalence (ambivalent or univalent toward eating junk food) by health message framing (advantage- or disadvantage-framed appeals) between-subjects experiment was conducted to explore a cognitive resource-matching effect and the underlying mediation processes. Ambivalent individuals reported a higher level of cognitive elaboration than univalent individuals did. The disadvantage frame engendered more extensive cognitive elaboration than the advantage frame did. Ambivalent individuals were more persuaded by the disadvantage frame and, for them, cognitive elaboration mediated the persuasion process via the systematic route. Univalent individuals were equally persuaded by the advantage frame and the disadvantage frame and, for them, neither the perceived frame valence nor cognitive elaboration mediated persuasion. Discussion of the null results among the univalent group leads to a response-reinforcement explanation. Theoretical and practical implications are discussed.

  11. State Policies Targeting Junk Food in Schools: Racial/Ethnic Differences in the Effect of Policy Change on Soda Consumption

    Science.gov (United States)

    Stevens, June; Evenson, Kelly R.; Ward, Dianne S.; Poole, Charles; Maciejewski, Matthew L.; Murray, David M.; Brownson, Ross C.

    2011-01-01

    Objectives. We estimated the association between state policy changes and adolescent soda consumption and body mass index (BMI) percentile, overall and by race/ethnicity. Methods. We obtained data on whether states required or recommended that schools prohibit junk food in vending machines, snack bars, concession stands, and parties from the 2000 and 2006 School Health Policies and Programs Study. We used linear mixed models to estimate the association between 2000–2006 policy changes and 2007 soda consumption and BMI percentile, as reported by 90 730 students in 33 states and the District of Columbia in the Youth Risk Behavior Survey, and to test for racial/ethnic differences in the associations. Results. Policy changes targeting concession stands were associated with 0.09 fewer servings of soda per day among students (95% confidence interval [CI] = −0.17, −0.01); the association was more pronounced among non-Hispanic Blacks (0.19 fewer servings per day). Policy changes targeting parties were associated with 0.07 fewer servings per day (95% CI = −0.13, 0.00). Policy changes were not associated with BMI percentile in any group. Conclusions. State policies targeting junk food in schools may reduce racial/ethnic disparities in adolescent soda consumption, but their impact appears to be too weak to reduce adolescent BMI percentile. PMID:21778484

  12. State policies targeting junk food in schools: racial/ethnic differences in the effect of policy change on soda consumption.

    Science.gov (United States)

    Taber, Daniel R; Stevens, June; Evenson, Kelly R; Ward, Dianne S; Poole, Charles; Maciejewski, Matthew L; Murray, David M; Brownson, Ross C

    2011-09-01

    We estimated the association between state policy changes and adolescent soda consumption and body mass index (BMI) percentile, overall and by race/ethnicity. We obtained data on whether states required or recommended that schools prohibit junk food in vending machines, snack bars, concession stands, and parties from the 2000 and 2006 School Health Policies and Programs Study. We used linear mixed models to estimate the association between 2000-2006 policy changes and 2007 soda consumption and BMI percentile, as reported by 90 730 students in 33 states and the District of Columbia in the Youth Risk Behavior Survey, and to test for racial/ethnic differences in the associations. Policy changes targeting concession stands were associated with 0.09 fewer servings of soda per day among students (95% confidence interval [CI] = -0.17, -0.01); the association was more pronounced among non-Hispanic Blacks (0.19 fewer servings per day). Policy changes targeting parties were associated with 0.07 fewer servings per day (95% CI = -0.13, 0.00). Policy changes were not associated with BMI percentile in any group. State policies targeting junk food in schools may reduce racial/ethnic disparities in adolescent soda consumption, but their impact appears to be too weak to reduce adolescent BMI percentile.

  13. Deep investigation of Arabidopsis thaliana junk DNA reveals a continuum between repetitive elements and genomic dark matter.

    Science.gov (United States)

    Maumus, Florian; Quesneville, Hadi

    2014-01-01

    Eukaryotic genomes contain highly variable amounts of DNA with no apparent function. This so-called junk DNA is composed of two components: repeated and repeat-derived sequences (together referred to as the repeatome), and non-annotated sequences also known as genomic dark matter. Because of their high duplication rates as compared to other genomic features, transposable elements are predominant contributors to the repeatome and the products of their decay is thought to be a major source of genomic dark matter. Determining the origin and composition of junk DNA is thus important to help understanding genome evolution as well as host biology. In this study, we have used a combination of tools enabling to show that the repeatome from the small and reducing A. thaliana genome is significantly larger than previously thought. Furthermore, we present the concepts and results from a series of innovative approaches suggesting that a significant amount of the A. thaliana dark matter is of repetitive origin. As a tentative standard for the community, we propose a deep compendium annotation of the A. thaliana repeatome that may help addressing farther genome evolution as well as transcriptional and epigenetic regulation in this model plant.

  14. Children's implicit recall of junk food, alcohol and gambling sponsorship in Australian sport.

    Science.gov (United States)

    Bestman, Amy; Thomas, Samantha L; Randle, Melanie; Thomas, Stuart D M

    2015-10-05

    In Australia, sport is saturated by the promotion of junk food, alcohol and gambling products. This is particularly evident on player jerseys. The effect of this advertising on children, who are exposed to these messages while watching sport, has not been thoroughly investigated. The aim of this research study was to investigate: (1) the extent to which children implicitly recalled shirt sponsors with the correct sporting team; (2) whether children associated some types of sponsors with certain sporting codes more than others; and (3) whether age of the children influenced the correct recall of sponsoring brands and teams. This experimental study conducted in New South Wales, Australia used projective techniques to measure the implicit recall of team sponsorship relationships of 85 children aged 5-12 years. Participants were asked to arrange two sets of magnets - one which contained sporting teams and one which contained brand logos - in the manner deemed most appropriate by them. Children were not given any prompts relating to sporting sponsorship relationships. Three quarters (77 %) of the children were able to identify at least one correct shirt sponsor. Children associated alcohol and gambling brands more highly with the more popular sporting code, the National Rugby League compared to the Australian Football League sporting code. Results showed that age had an effect on number of shirt sponsors correctly recalled with 9-12 year olds being significantly more likely than 5-8 year olds to correctly identify team sponsors. Given children's ability to implicitly recall shirt sponsors in a sporting context, Australian sporting codes should examine their current sponsorship relationships to reduce the number of unhealthy commodity shirt sponsors. While there is some regulation that protects children from the marketing of unhealthy commodity products, these findings suggest that children are still exposed to and recall these sponsorship relationships. Results suggest

  15. Association of junk food consumption with high blood pressure and obesity in Iranian children and adolescents: the CASPIAN-IV Study

    Directory of Open Access Journals (Sweden)

    Moloud Payab

    2015-04-01

    Full Text Available OBJECTIVE: This study aimed to evaluate the association of junk food consumption with hypertension and obesity in a national sample of Iranian children and adolescents. METHODS: This nationwide study was conducted in 2011-2012 among 14,880 students, aged 6-18 years, selected by cluster sampling from 30 provinces. Weight, height, waist circumference (WC, hip circumference (HC, waist-to-hip ratio (WHR, waist-to-height ratio (WHtR, as well as systolic and diastolic blood pressure (BP were measured. Junk food was divided into four categories, including salty snacks, sweets, sweetened beverages, and fast food. Subjects reported how many times they had consumed each item (daily, weekly, and seldom. RESULTS: The intake of sweets was significantly associated with anthropometric indices and BP levels. Moreover, a significant association was found between fast food consumption, BP levels, and anthropometric indices (except for WHtR and WHR. Sweet beverages consumption was significantly associated with anthropometric indices; however, the consumption of salty snacks was only significantly associated with height, HC, and WHR. The risk of general obesity (OR: 0.75, 95% CI: 0.65-0.87 and abdominal obesity (OR: 0.81, 95% CI: 0.72-0.92 among participants who seldom consumed sweets was less than those who consumed daily. Also, the risk of general obesity (OR: 0.85, 95% CI: 0.74-0.97 among students that seldom consumed sweetened beverages was less than subjects who consumed them on a daily basis. CONCLUSION: It was found that junk food consumption increased the risk of both general and abdominal obesity; therefore, consumption of junk food should be reduced via restricting TV advertisements and increasing taxes on junk foods.

  16. Association of junk food consumption with high blood pressure and obesity in Iranian children and adolescents: the CASPIAN-IV Study.

    Science.gov (United States)

    Payab, Moloud; Kelishadi, Roya; Qorbani, Mostafa; Motlagh, Mohammad Esmaeil; Ranjbar, Shirin Hasani; Ardalan, Gelayol; Zahedi, Hoda; Chinian, Mohammad; Asayesh, Hamid; Larijani, Bagher; Heshmat, Ramin

    2015-01-01

    This study aimed to evaluate the association of junk food consumption with hypertension and obesity in a national sample of Iranian children and adolescents. This nationwide study was conducted in 2011-2012 among 14,880 students, aged 6-18 years, selected by cluster sampling from 30 provinces. Weight, height, waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), as well as systolic and diastolic blood pressure (BP) were measured. Junk food was divided into four categories, including salty snacks, sweets, sweetened beverages, and fast food. Subjects reported how many times they had consumed each item (daily, weekly, and seldom). The intake of sweets was significantly associated with anthropometric indices and BP levels. Moreover, a significant association was found between fast food consumption, BP levels, and anthropometric indices (except for WHtR and WHR). Sweet beverages consumption was significantly associated with anthropometric indices; however, the consumption of salty snacks was only significantly associated with height, HC, and WHR. The risk of general obesity (OR: 0.75, 95% CI: 0.65-0.87) and abdominal obesity (OR: 0.81, 95% CI: 0.72-0.92) among participants who seldom consumed sweets was less than those who consumed daily. Also, the risk of general obesity (OR: 0.85, 95% CI: 0.74-0.97) among students that seldom consumed sweetened beverages was less than subjects who consumed them on a daily basis. It was found that junk food consumption increased the risk of both general and abdominal obesity; therefore, consumption of junk food should be reduced via restricting TV advertisements and increasing taxes on junk foods. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  17. Cross-sectional survey of daily junk food consumption, irregular eating, mental and physical health and parenting style of British secondary school children.

    Science.gov (United States)

    Zahra, J; Ford, T; Jodrell, D

    2014-07-01

    Previous research has established that poor diets and eating patterns are associated with numerous adverse health outcomes. This study explored the relationships between two specific eating behaviours (daily junk food consumption and irregular eating) and self-reported physical and mental health of secondary school children, and their association with perceived parenting and child health. 10 645 participants aged between 12 and 16 completed measures of junk food consumption, irregular eating, parental style, and mental and physical health through the use of an online survey implemented within 30 schools in a large British city. 2.9% of the sample reported never eating regularly and while 17.2% reported daily consumption of junk food. Young people who reported eating irregularly and consuming junk food daily were at a significantly greater risk of poorer mental (OR 5.41, 95% confidence interval 4.03-7.25 and 2.75, 95% confidence interval 1.99-3.78) and physical health (OR 4.56, 95% confidence interval 3.56-5.85 and 2.00, 95% confidence interval 1.63-2.47). Authoritative parenting was associated with healthier eating behaviours, and better mental and physical health in comparison to other parenting styles. A worrying proportion of secondary school children report unhealthy eating behaviours, particularly daily consumption of junk food, which may be associated with poorer mental and physical health. Parenting style may influence dietary habits. Interventions to improve diet may be more beneficial if also they address parenting strategies and issues related to mental and physical health. © 2013 John Wiley & Sons Ltd.

  18. Junk food diet-induced obesity increases D2 receptor autoinhibition in the ventral tegmental area and reduces ethanol drinking.

    Science.gov (United States)

    Cook, Jason B; Hendrickson, Linzy M; Garwood, Grant M; Toungate, Kelsey M; Nania, Christina V; Morikawa, Hitoshi

    2017-01-01

    Similar to drugs of abuse, the hedonic value of food is mediated, at least in part, by the mesostriatal dopamine (DA) system. Prolonged intake of either high calorie diets or drugs of abuse both lead to a blunting of the DA system. Most studies have focused on DAergic alterations in the striatum, but little is known about the effects of high calorie diets on ventral tegmental area (VTA) DA neurons. Since high calorie diets produce addictive-like DAergic adaptations, it is possible these diets may increase addiction susceptibility. However, high calorie diets consistently reduce psychostimulant intake and conditioned place preference in rodents. In contrast, high calorie diets can increase or decrease ethanol drinking, but it is not known how a junk food diet (cafeteria diet) affects ethanol drinking. In the current study, we administered a cafeteria diet consisting of bacon, potato chips, cheesecake, cookies, breakfast cereals, marshmallows, and chocolate candies to male Wistar rats for 3-4 weeks, producing an obese phenotype. Prior cafeteria diet feeding reduced homecage ethanol drinking over 2 weeks of testing, and transiently reduced sucrose and chow intake. Importantly, cafeteria diet had no effect on ethanol metabolism rate or blood ethanol concentrations following 2g/kg ethanol administration. In midbrain slices, we showed that cafeteria diet feeding enhances DA D2 receptor (D2R) autoinhibition in VTA DA neurons. These results show that junk food diet-induced obesity reduces ethanol drinking, and suggest that increased D2R autoinhibition in the VTA may contribute to deficits in DAergic signaling and reward hypofunction observed with obesity.

  19. The Effect of nutrition education on knowledge, attitude, and performance about junk food consumption among students of female primary schools.

    Science.gov (United States)

    Vardanjani, Ali Esmaeili; Reisi, Mahnoush; Javadzade, Homamodin; Pour, Zabihollah Gharli; Tavassoli, Elahe

    2015-01-01

    Undoubtedly, proper nutrition has important role in safeguarding the individual from many diseases, especially chronic ones, and increasing ones physical and intellectual efficiency. Considering the importance of nutrition education to school-age kids, this research was done with the purpose of determining the effect of nutrition education on the knowledge, attitude, and performance of female students at primary school about junk food consumption. This is an experimental intervention study in Shahr-e-kord city about the reduction of junk foods consumption in 2011. Seventy-two primary girl students were randomly divided into 2 groups, experimental (36) and controls (36). Before of the educational program, self-administrative questionnaire and FFQ (Food Frequency Questionnaire) questionnaire were filled out for both the groups. The self-administrative questionnaire was completed 3 times (before, immediately, and 2 months after education), and FFQ questionnaire was completed 2 times (before and 2 months after education) by students. After pre-test, 4 educational session classes in experimental group were performed. Finally, data were collected and analyzed by SPSS 16 computer software. Demographic variables of the studied population in 2 groups were similar. Before intervention, there were no significant differences regarding the knowledge, attitude, and performance in 2 groups (P > 0/05). After intervention, there were significant differences in the levels of knowledge, attitude, and performance between experimental and control groups (P < 0.001). According to the results, intervention has positive impact on pattern of nutrition, and it can be concluded that intervention is effective on increasing or improving the knowledge, attitude, and performance of the students.

  20. Consuming a low-fat diet from weaning to adulthood reverses the programming of food preferences in male, but not in female, offspring of 'junk food'-fed rat dams.

    Science.gov (United States)

    Ong, Z Y; Muhlhausler, B S

    2014-01-01

    This study aimed to determine whether the negative effects of maternal 'junk food' feeding on food preferences and gene expression in the mesolimbic reward system could be reversed by weaning the offspring onto a low-fat diet. Offspring of control (n = 11) and junk food-fed (JF, n = 12) dams were weaned onto a standard rodent chow until 6 weeks (juvenile) or 3 months (adult). They were then given free access to both chow and junk food for 3 weeks and food preferences determined. mRNA expression of key components of the mesolimbic reward system was determined by qRT-PCR at 6 weeks, 3 and 6 months of age. In the juvenile group, both male and female JF offspring consumed more energy and carbohydrate during the junk food exposure at 6 weeks of age and had a higher body fat mass at 3 months (P junk food; however, female JF offspring had a higher body fat mass at 6 months (P junk food exposure on food preferences and fat mass can be reversed by consuming a low-fat diet from weaning to adulthood in males. Females, however, retain a higher propensity for diet-induced obesity even after consuming a low-fat diet for an extended period after weaning. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  1. Observation of antimicrobial activity of Junke cream in vitro%菌克软膏体外抗菌活性观察

    Institute of Scientific and Technical Information of China (English)

    邵留英; 瞿发林; 陈颖; 倪玉佳; 吴晓燕

    2015-01-01

    目的:观察菌克软膏的体外抗菌活性。方法采用琼脂扩散法进行药敏试验,测定菌克软膏对4种6株标准致病细菌、9种23株标准致病真菌的抑菌圈直径,并与林可霉素软膏和硝酸咪康唑软膏进行对比。结果菌克软膏对4种常见细菌都形成抑菌圈,且对金黄色葡萄球菌、大肠杆菌和枯草杆菌的抑菌圈直径均大于林可霉素软膏(P0.05)。菌克软膏对9种常见真菌都形成抑菌圈,且对各种皮肤癣菌、念珠菌、裴氏着色真菌和糠秕马拉色菌的抑菌圈直径与硝酸咪康唑软膏组比较差异无统计学意义( P>0.05)。结论菌克软膏体外抗细菌活性强于林可霉素软膏,抗真菌活性强度与硝酸咪康唑软膏相同。%Objective To observe the antimicrobial activity of Junke cream in vitro. Methods The drug sus-ceptibility was detected by agar diffusion method. The inhibition zone diameters of Junke cream against 6 isolates of pathogenic bacteria from 4 species,and 23 isolates of pathogenic fungi from 9 species were determined,and the diame-ters of Junke cream were compared with those of lincomycin cream and miconazole nitrate cream. Results The inhibi-tion zones of Junke cream against common pathogenic bacteria from 4 species were observed. The inhibition zones di-ameters of Junke cream against staphylococcus aureus,escherichia coli. and bacillus subtilis were both larger than those of lincomycin cream ( P 0. 05 ) . The inhibition zones of Junke cream against common pathogenic fungi from 9 species were observed. There was no significant difference in the inhibition zones diameters of Junke cream and micon-azole nitrate cream against the dermatophyte,candida spp,fonsecaea pedrosoi and malassezia furfur (P>0. 05). Con-clusion The antibacterial activity of Junke cream was greater than lincomycin cream,and the antifungi activity was similar as miconazole nitrate cream in vitro.

  2. Association between energy drink intake, sleep, stress, and suicidality in Korean adolescents: energy drink use in isolation or in combination with junk food consumption

    OpenAIRE

    Park, Subin; Lee, Yeeun; Lee, Junghyun H.

    2016-01-01

    Background A considerable amount of research suggests that the frequent use of caffeinated energy drinks may be associated with undesirable effects, particularly so in children and adolescents. This study aimed to investigate the associations between energy drink intake and mental health problems, in isolation or in combination with junk food consumption, in a nationally representative sample of Korean adolescents. Methods Data from the 2015 Korean Youth Risk Behavior Web-Based Survey, collec...

  3. Assessment of the Situation and the Cause of Junk Food Consumption in Iran and Recommendation of Interventions for Reducing its Consumption

    Directory of Open Access Journals (Sweden)

    Behzad Damari

    2016-05-01

    Full Text Available Background and Objective: The consumption of junk food in Iran is alarmingly increasing. This study aimed to determine the influencing factors of junk food consumption and amendable interventions for decreasing  the consumption.Materials and Methods: In this qualitative study, Valid documentations were collected by searching the database using related key words and the key points were imported in a checklist and after identifying and prioritizing stakeholders through stakeholder analysis method, it was provided to stakeholders in the form of a questionnaire. The qualitative Method was Delphi. The questionnaire was sent by email to stakeholders and they asked to select and prioritize problems and required interventions. Consensus was reached after three rounds.      Results: The study showed that mean junk food consumption was high in Iran, especially in children and adolescents and the most important influencing factors was availability, low price, the impact of media, taste preferences, diversity and attractiveness of the package, inadequate awareness and lifestyle changes. Recommended interventions by stakeholders was including creation of a supportive environment, educational interventions, increased access to healthy food and control junk-food advertising in the media and imposed major changes in supportive priorities of  ministry of industry and mining toward producing healthy snacks.Conclusion: According to the findings, in line with public Policymaking, presentation of the results of this study as an advocacy paper to health policymakers and integrating it in the operational programs of the ministries of Health and Education and the media and holding supportive meetings with the producers of alternative products is proposed.

  4. Maternal “junk-food” feeding of rat dams alters food choices and development of the mesolimbic reward pathway in the offspring

    Science.gov (United States)

    Ong, Z. Y.; Muhlhausler, B. S.

    2011-01-01

    Individuals exposed to high-fat, high-sugar diets before birth have an increased risk of obesity in later life. Recent studies have shown that these offspring exhibit increased preference for fat, leading to suggestions that perinatal exposure to high-fat, high-sugar foods results in permanent changes within the central reward system that increase the subsequent drive to overconsume palatable foods. The present study has determined the effect of a maternal “junk-food” diet on the expression of key components of the mesolimbic reward pathway in the offspring of rat dams at 6 wk and 3 mo of age. We show that offspring of junk-food-fed (JF) dams exhibit higher fat intake from weaning until at least 3 mo of age (males: 16±0.6 vs. 11±0.8 g/kg/d; females: 19±1.3 vs. 13±0.4 g/kg/d; Pjunk-food intake in postnatal life.—Ong, Z. Y., Muhlhausler, B. S. Maternal “junk-food” feeding of rat dams alters food choices and development of the mesolimbic reward pathway in the offspring. PMID:21427213

  5. Does breast-feeding reduce offspring junk food consumption during childhood? Examinations by socio-economic status and race/ethnicity.

    Science.gov (United States)

    Jackson, Dylan B; Johnson, Kecia R

    2017-06-01

    To examine whether breast-feeding duration and socio-economic status (SES) interact to predict junk food consumption among offspring and whether the interaction differs across racial/ethnic groups. Survey research using a longitudinal panel design. Hierarchical linear regression was used to analyse the data. In-home interviews with the child's parents over a 5-year period across the USA. Approximately 10 000 American children from the Early Childhood Longitudinal Study: Birth Cohort (ECLS-B). The findings revealed that longer breast-feeding durations correspond to lower levels of junk food consumption, but that this relationship emerges consistently only among low-SES blacks. Efforts to promote breast-feeding among low-SES black women may have the added benefit of reducing their children's junk food intake, and may thereby promote their general health and well-being. Future research should seek to explore the mechanisms by which breast-feeding might benefit the dietary habits of low-SES black children.

  6. Relationship between junk foods intake and weight in 6-7 years old children, Shahin Shahr and Meymeh, Iran.

    Science.gov (United States)

    Darvishi, Leila; Ghiasvand, Reza; Ashrafi, Maryam; Ashrafzadeh, Elnaz; Askari, Gholamreza; Shiranian, Afshin; Hasanzadeh, Akbar

    2013-01-01

    Healthy nutrition is very important considering the weight status especially in children. The aim of this study was to assess the relationship between junk foods intake and weight in 6-7-years old children. This cross-sectional study was carried out in Shahin Shahr and Meymeh, Iran, in 2009. Anthropometrics measures were done and 24-hour food recall used for dietary information and analyzed with food processor 2 and then compared with dietary reference intakes 2008 (DRI). 61.1 percent of the subjects were residing in dormitories and 12.7 percent were marred. Prevalence of overweight or obesity and abdominal obesity was 6.9 percent and 46.1 percent respectively. Mean (±SD) systolic blood pressure was 105.2 ± 15.6 mm/Hg and diastolic was 62.2 ± 10.4 mm/Hg. Totally, 3.9 percent of the subjects had hypertension. The analysis of food intake indicate that (B12, folate, magnesium, potassium, calcium) with level below the recommended ones, and (vitamin C, E, pantothenic acid, B1, B3, phosphate, zinc) with up levels the recommended ones, and energy intake, macronutrient, vitamin A, pyridoxine, iron, selenium were in general appropriate. These results indicated appropriate level of macronutrients intake and unbalance mainly existed in micronutrients. It is recommended to increase intake important food groups such as dairy, vegetable, fruit that include good source of micronutrients, and also it is suggested that need for strategies can improve competence in the area of nutrition.

  7. Relationship between junk foods intake and weight in 6-7 years old children, Shahin Shahr and Meymeh, Iran

    Science.gov (United States)

    Darvishi, Leila; Ghiasvand, Reza; Ashrafi, Maryam; Ashrafzadeh, Elnaz; Askari, Gholamreza; Shiranian, Afshin; Hasanzadeh, Akbar

    2013-01-01

    Background: Healthy nutrition is very important considering the weight status especially in children. The aim of this study was to assess the relationship between junk foods intake and weight in 6-7-years old children. Materials and Methods: This cross-sectional study was carried out in Shahin Shahr and Meymeh, Iran, in 2009. Anthropometrics measures were done and 24-hour food recall used for dietary information and analyzed with food processor 2 and then compared with dietary reference intakes 2008 (DRI). Findings: 61.1 percent of the subjects were residing in dormitories and 12.7 percent were marred. Prevalence of overweight or obesity and abdominal obesity was 6.9 percent and 46.1 percent respectively. Mean (±SD) systolic blood pressure was 105.2 ± 15.6 mm/Hg and diastolic was 62.2 ± 10.4 mm/Hg. Totally, 3.9 percent of the subjects had hypertension. The analysis of food intake indicate that (B12, folate, magnesium, potassium, calcium) with level below the recommended ones, and (vitamin C, E, pantothenic acid, B1, B3, phosphate, zinc) with up levels the recommended ones, and energy intake, macronutrient, vitamin A, pyridoxine, iron, selenium were in general appropriate. Conclusion: These results indicated appropriate level of macronutrients intake and unbalance mainly existed in micronutrients. It is recommended to increase intake important food groups such as dairy, vegetable, fruit that include good source of micronutrients, and also it is suggested that need for strategies can improve competence in the area of nutrition. PMID:24083252

  8. Association of junk food consumption with high blood pressure and obesity in Iranian children and adolescents: the CASPIAN-IV Study

    OpenAIRE

    Moloud Payab; Roya Kelishadi; Mostafa Qorbani; Mohammad Esmaeil Motlagh; Shirin Hasani Ranjbar; Gelayol Ardalan; Hoda Zahedi; Mohammad Chinian; Hamid Asayesh; Bagher Larijani; Ramin Heshmat

    2015-01-01

    OBJECTIVE: This study aimed to evaluate the association of junk food consumption with hypertension and obesity in a national sample of Iranian children and adolescents. METHODS: This nationwide study was conducted in 2011-2012 among 14,880 students, aged 6-18 years, selected by cluster sampling from 30 provinces. Weight, height, waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), as well as systolic and diastolic blood pressure (BP) were m...

  9. Association of junk food consumption with high blood pressure and obesity in Iranian children and adolescents: the CASPIAN-IV Study

    OpenAIRE

    Moloud Payab; Roya Kelishadi; Mostafa Qorbani; Mohammad Esmaeil Motlagh; Shirin Hasani Ranjbar; Gelayol Ardalan; Hoda Zahedi; Mohammad Chinian; Hamid Asayesh; Bagher Larijani; Ramin Heshmat

    2015-01-01

    OBJECTIVE: This study aimed to evaluate the association of junk food consumption with hypertension and obesity in a national sample of Iranian children and adolescents. METHODS: This nationwide study was conducted in 2011-2012 among 14,880 students, aged 6-18 years, selected by cluster sampling from 30 provinces. Weight, height, waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), as well as systolic and diastolic blood pressure (BP) were m...

  10. Association between energy drink intake, sleep, stress, and suicidality in Korean adolescents: energy drink use in isolation or in combination with junk food consumption.

    Science.gov (United States)

    Park, Subin; Lee, Yeeun; Lee, Junghyun H

    2016-10-13

    A considerable amount of research suggests that the frequent use of caffeinated energy drinks may be associated with undesirable effects, particularly so in children and adolescents. This study aimed to investigate the associations between energy drink intake and mental health problems, in isolation or in combination with junk food consumption, in a nationally representative sample of Korean adolescents. Data from the 2015 Korean Youth Risk Behavior Web-Based Survey, collected from 68,043 adolescents aged 12-18 years (mean age 15.09 ± 1.72 years), were analyzed. Questionnaires were administered to collect information related to dietary behavior including energy drink intake and junk food consumption. Single item measures of sleep dissatisfaction, stress, depression, suicidal ideation, suicide plan, and suicide attempt were also administered. Associations between energy drink intake and sleep dissatisfaction, perceived severe stress, persistent depressive mood, and suicidality were investigated, and a multivariate approach was taken so that additional variance from demographic and lifestyle factors could be controlled for statistically. Energy drink intake was significantly associated with sleep dissatisfaction (adjusted odd ratios [AORs] = 1.64 and 1.25), severe stress (AORs = 2.23 and 1.38), depressive mood (AOR = 2.59 and 1.51), suicidal ideation (AORs = 3.14 and 1.43), suicide plan (AORs = 4.65 and 1.78), and suicide attempt (AORs = 6.79 and 1.91), with a higher risk for more frequent use of energy drinks (≥5 times/wk) than for less frequent use (1-4 times/wk). The detrimental effect of energy drinks on mental health was particularly prominent in frequent junk food consumers. Our data suggest that energy drink intake had detrimental effects related to stress, sleep dissatisfaction, mood, and suicidality, in isolation or in combination with junk food consumption, in Korean adolescents. However, the cross-sectional study design

  11. “耆英号”与“卡蒂萨克号”古帆船%While ‘Junk Keying’ Meets ‘Cutty Sark’

    Institute of Scientific and Technical Information of China (English)

    尤泽峰

    2015-01-01

    Junk Keying’ departed from Hong Kong in 1846, through Cape of Good Hope, New York and Boston, reached London, and became the ifrst Chinese wooden junk across the Atlantic in history. In 1872, a typical British Clipper ‘Cutty Sark’ started off her journey from London, sailing to a new destination in Shanghai China. These two ships never met, but share similarities, also difference. The paper through two ships’ historical background, and current fate, elaborates the maritime history and culture , traditional shipbuilding technology between the East and the West.%1846年,中国帆船“耆英号”从香港出发,穿越大西洋到达英国伦敦,成为中国第一艘穿越大西洋的木帆船。1872年,英式帆船“卡蒂萨克”从英国伦敦启航,驶向中国上海。两艘帆船虽未相遇,但已经相识,中西方的海航文明和造船工艺不断相互影响。

  12. Maternal "junk-food" feeding of rat dams alters food choices and development of the mesolimbic reward pathway in the offspring.

    Science.gov (United States)

    Ong, Z Y; Muhlhausler, B S

    2011-07-01

    Individuals exposed to high-fat, high-sugar diets before birth have an increased risk of obesity in later life. Recent studies have shown that these offspring exhibit increased preference for fat, leading to suggestions that perinatal exposure to high-fat, high-sugar foods results in permanent changes within the central reward system that increase the subsequent drive to overconsume palatable foods. The present study has determined the effect of a maternal "junk-food" diet on the expression of key components of the mesolimbic reward pathway in the offspring of rat dams at 6 wk and 3 mo of age. We show that offspring of junk-food-fed (JF) dams exhibit higher fat intake from weaning until at least 3 mo of age (males: 16 ± 0.6 vs. 11 ± 0.8 g/kg/d; females: 19 ± 1.3 vs. 13 ± 0.4 g/kg/d; Pjunk-food intake in postnatal life.

  13. Sex and age-dependent effects of a maternal junk food diet on the mu-opioid receptor in rat offspring.

    Science.gov (United States)

    Gugusheff, Jessica R; Bae, Sung Eun; Rao, Alexandra; Clarke, Iain J; Poston, Lucilla; Taylor, Paul D; Coen, Clive W; Muhlhausler, Beverly S

    2016-03-15

    Perinatal junk food exposure increases the preference for palatable diets in juvenile and adult rat offspring. Previous studies have implicated reduced sensitivity of the opioid pathway in the programming of food preferences; however it is not known when during development these changes in opioid signalling first emerge. This study aimed to determine the impact of a maternal junk food (JF) diet on mu-opioid receptor (MuR) expression and ligand binding in two key regions of the reward pathway, the nucleus accumbens (NAc) and the ventral tegmental area (VTA) in rats during the early suckling (postnatal day (PND) 1 and 7) and late suckling/early post-weaning (PND 21 and 28) periods. Female rats were fed either a JF or a control diet for two weeks prior to mating and throughout pregnancy and lactation. MuR expression in the VTA was significantly reduced in female JF offspring on PND 21 and 28 (by 32% and 57% respectively, Pjunk food exposure on MuR mRNA expression or binding were detected at these time points in male offspring. These findings provide evidence that the opioid signalling system is a target of developmental programming by the end of the third postnatal week in females, but not in males. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Contexts Paired with Junk Food Impair Goal-Directed Behavior in Rats: Implications for Decision Making in Obesogenic Environments.

    Science.gov (United States)

    Kendig, Michael D; Cheung, Ambrose M K; Raymond, Joel S; Corbit, Laura H

    2016-01-01

    The high prevalence of obesity and related metabolic diseases calls for greater understanding of the factors that drive excess energy intake. Calorie-dense palatable foods are readily available and often are paired with highly salient environmental cues. These cues can trigger food-seeking and consumption in the absence of hunger. Here we examined the effects of palatable food-paired environmental cues on control of instrumental food-seeking behavior. In Experiment 1, adult male rats received exposures to one context containing three "junk" foods (JFs context) and another containing chow (Chow context). Next, rats were food-deprived and trained to perform instrumental responses (lever-press) for two novel food rewards in a third, distinct context. Contextual influences on flexible control of food-seeking behavior were then assessed by outcome devaluation tests held in the JF, chow and training contexts. Devaluation was achieved using specific satiety and test order was counterbalanced. Rats exhibited goal-directed control over behavior when tested in the training and chow-paired contexts. Notably, performance was habitual (insensitive to devaluation) when tested in the JF context. In Experiment 2 we tested whether the impairment found in the JF context could be ameliorated by the presentation of a discrete auditory cue paired with the chow context, relative to a second cue paired with the JF context. Consistent with the results of Experiment 1, the devaluation effect was not significant when rats were tested in the JF context with the JF cue. However, presenting the chow cue increased the impact of the devaluation treatment leading to a robust devaluation effect. Further tests confirmed that performance in the chow context was goal-directed and that sensory-specific satiety in the JF context was intact. These results show that environments paired with palatable foods can impair goal-directed control over food-seeking behavior, but that this deficit was improved by

  15. Rich on Junk

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A poor boy grew into a billionaire through years of hard work The signs of business acumen had already appeared in Chen Guangbiao as early as 1978, when he was just a 10-year-old being raised in a poor farming family.

  16. Simple Machine Junk Cars

    Science.gov (United States)

    Herald, Christine

    2010-01-01

    During the month of May, the author's eighth-grade physical science students study the six simple machines through hands-on activities, reading assignments, videos, and notes. At the end of the month, they can easily identify the six types of simple machine: inclined plane, wheel and axle, pulley, screw, wedge, and lever. To conclude this unit,…

  17. Junk Yard Treasures

    Science.gov (United States)

    Mathes, Len

    2009-01-01

    The author describes a project that she developed as a challenge for her students and ended up with some fantastic student paintings. The author told her group of reluctant art students they must first research on the Internet for old, junky cars. The older and more junky the cars, the better. Once a vehicle is selected, it is driven into Adobe…

  18. Stocks, Junk and Pharmaceuticals

    Institute of Scientific and Technical Information of China (English)

    何伟文

    2004-01-01

    Stock analysts in the West have recently been taking a close look at markets in the East. Among their favourites were Chinese stock funds, even though the bourses in Shanghai and Shenzhen tumbled to historic lows. But of course it is the long-term promise that counts and given the rather sombre and gloomy economic mood in Europe, this most probably will make sense for the near and, hopefully, more distant future. Nevertheless, qualified foreign institutional investors should take precautions and in our Focus (pp.20) section we pose the question of how these investors should adjust their portfolios.

  19. Implantation of the NC ISO 9001 in the Radioactivity measurement service in junks of CPHR; Implantacion de la NC ISO 9001 en el servicio de medicion de radiactividad en chatarras de CPHR

    Energy Technology Data Exchange (ETDEWEB)

    Ramos V, E.O.; Dominguez L, O.; Capote F, E.; Fernandez G, I.M.; Caveda R, C.; Alonso A, D.; Barroso P, I.; Madraso M, S. [CPHR, Calle 20 No. 4113 e/41 y 47 Playa, C.P. 11300, Ciudad La Habana, Direccion Postal A.P. 6195, C.P. 10600 (Cuba)]. e-mail: odalys@cphr.edu.cu

    2006-07-01

    In the last years in the international environment, radiological incidents have been reported, due to the presence of radioactive materials in the junk, that have implied the adoption of measures in matter of radiological safety, to avoid affectations in the public and the environment, as well as in the international trade. The establishment of the radiological control of junk during it commercialization requires of the implantation of a quality management program. In such sense, the present work exposes the experience of our institution in the design and organization of a service for the radioactivity measurement in junks based on a quality administration system based on the requirements of the quality standards ISO 9001:2000, ISO/IEC 17050 and ISO/IEC 17025:2000. In coherence with the postulates defined in the institutional strategy related to the implantation of a total quality system and the international demands on this matter. To such ends the processes that compose the service were identified, the corresponding and implemented procedures were elaborated, the registrations associated to the same one, being worked in the design of a quality assurance program that allowed the evaluation of the conformity of the product and the customer. (Author)

  20. A JUNK FROM [H.] 1285 YEAR AND ITS LANGUAGE CHARACTERISTICS [H.] 1285 TARİHLİ BİR CÖNK VE DİL ÖZELLİKLERİ

    Directory of Open Access Journals (Sweden)

    Yakup YILMAZ

    2011-12-01

    Full Text Available The junks are one of the sources of folk’s literature. These aregenerally stayed in libraries, but a few people also have some of them. Itis always possible to attain to Junks which are staying in libraries but itis not easy to attain the others. These junks can be examined fromdifferent standpoint according to their contents. The junks project topoetry’s mentality, popular poetries and language of their age. This junkfrom H. 1285 year includes a wide time from 13. era to 20. era in point oflanguage. The language of poems in junk has protected originalcharacteristics. While it is replicated, they haven’t been adapted to thelanguage of era. Characteristics of Old Anatolian Turkish, OttomanTurkish and Turkey Turkish has been seen together. Cönkler, halk edebiyatı kaynaklarındandır. Bunlar, kütüphanelerdeyer alır; ancak bazı kişilerin ellerinde de bulunmaktadır.Kütüphanedekilere ulaşmak her zaman mümkün; ama bazı kişilerdekicönklere her zaman ulaşılamamaktadır. Bu cönkler muhtevasına vediline göre farklı noktalardan incelenebilir. Cönkler devrin şiir anlayışını,popüler şiirlerini ve dilini yansıtır. H. 1285 tarihli bu cönk, 13. asırdan20. asra kadar geniş bir zamanı kapsar. Cönkteki şiirlerin dili asliözelliklerini muhafaza etmişler, istinsah edilirken devrin dilineuyarlanmamışlardır. Eski Anadolu Türkçesi, Osmanlı Türkçesi veTürkiye Türkçesi özellikleri bir arada görülmektedir.

  1. The effects of prenatal exposure to a 'junk food' diet on offspring food preferences and fat deposition can be mitigated by improved nutrition during lactation.

    Science.gov (United States)

    Gugusheff, J R; Vithayathil, M; Ong, Z Y; Muhlhausler, B S

    2013-10-01

    Exposure to a maternal junk food (JF) diet in utero and during the suckling period has been demonstrated to increase the preference for palatable food and increase the susceptibility to diet-induced obesity in adult offspring. We aimed to determine whether the effects of prenatal exposure to JF could be ameliorated by cross-fostering offspring onto dams consuming a standard rodent chow during the suckling period. We report here that when all offspring were given free access to the JF diet for 7 weeks from 10 weeks of age, male offspring of control (C) or JF dams that were cross-fostered at birth onto JF dams (C-JF, JF-JF), exhibited higher fat (C-C: 12.3 ± 0.34 g/kg/day; C-JF: 14.7 ± 1.04 g/kg/day; JF-C: 11.5 ± 0.41 g/kg/day; JF-JF: 14.0 ± 0.44 g/kg/day; P food intake, had increased fat mass as percentage of body weight (C-C: 19.9 ± 1.33%; C-JF: 22.8 ± 1.57%; JF-C: 17.4 ± 1.03%; JF-JF: 22.0 ± 1.0%; P food preferences in females and susceptibility to diet-induced obesity in males can be prevented by improved nutrition during the suckling period.

  2. Perception v. actual intakes of junk food and sugar-sweetened beverages in Australian young adults: assessed using the mobile food record.

    Science.gov (United States)

    Harray, Amelia J; Boushey, Carol J; Pollard, Christina M; Panizza, Chloe E; Delp, Edward J; Dhaliwal, Satvinder S; Kerr, Deborah A

    2017-09-01

    To determine perception v. actual intakes of energy-dense nutrient-poor 'junk food' (JF) and sugar-sweetened beverages (SSB) in young adults, using the mobile food record (mFR). Before-and-after eating images using a 4 d mFR were assessed for standardised 600 kJ (143 kcal) servings of JF and SSB (excluding diet drinks). Participants reported their concern about the health aspects of their diet, perceptions and intentions regarding JF and SSB. Perth, Western Australia. Adults (n 246) aged 18-30 years. The mean (sd) intake of JF+SSB was 3·7 (2·0) servings/d. Women thinking about drinking less SSB consumed more SSB servings/d (1·5 (1·2)) than men (0·7 (0·5); Pfood (Pfoods represent an important target group as they consume more than their peers. Further research is needed to identify how amenable young adults are to changing their intake, particularly given the lack of attention paid to the health aspects of their diet.

  3. Modern 'junk food' and minimally-processed 'natural food' cafeteria diets alter the response to sweet taste but do not impair flavor-nutrient learning in rats.

    Science.gov (United States)

    Palframan, Kristen M; Myers, Kevin P

    2016-04-01

    Animals learn to prefer and increase consumption of flavors paired with postingestive nutrient sensing. Analogous effects have been difficult to observe in human studies. One possibility is experience with the modern, processed diet impairs learning. Food processing manipulates flavor, texture, sweetness, and nutrition, obscuring ordinary correspondences between sensory cues and postingestive consequences. Over time, a diet of these processed 'junk' foods may impair flavor-nutrient learning. This 'flavor-confusion' hypothesis was tested by providing rats long-term exposure to cafeteria diets of unusual breadth (2 or 3 foods per day, 96 different foods over 3 months, plus ad libitum chow). One group was fed processed foods (PF) with added sugars/fats and manipulated flavors, to mimic the sensory-nutrient properties of the modern processed diet. Another group was fed only 'natural' foods (NF) meaning minimally-processed foods without manipulated flavors or added sugars/fats (e.g., fresh fruits, vegetables, whole grains) ostensibly preserving the ordinary correspondence between flavors and nutrition. A CON group was fed chow only. In subsequent tests of flavor-nutrient learning, PF and NF rats consistently acquired strong preferences for novel nutrient-paired flavors and PF rats exhibited enhanced learned acceptance, contradicting the 'flavor-confusion' hypothesis. An unexpected finding was PF and NF diets both caused lasting reduction in ad lib sweet solution intake. Groups did not differ in reinforcing value of sugar in a progressive ratio task. In lick microstructure analysis the NF group paradoxically showed increased sucrose palatability relative to PF and CON, suggesting the diets have different effects on sweet taste evaluation. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Beauty in Chips:An Analysis of Aesthetic Features of Modern Junk Art from the Creating Perspective%碎片中的美丽--浅析当代废品艺术的审美特征

    Institute of Scientific and Technical Information of China (English)

    孙妮娜

    2014-01-01

    废品并不是真正意义上的垃圾,在废品的碎片中,我们应当发现它背后独特的美并加以利用。废品艺术既可以减轻城市负担,也可以美化城市环境。近年来,视觉艺术家持续关注和探索废品艺术的材料和形式,创造性地使用废品并探索它们共同的审美特征。通过独特的审美渗透和转变,废品艺术使这些废品焕发生机,并通过一系列独特的艺术表现对当代艺术和生活产生重要影响。%Junk does not really mean garbage in that the effective recycling can reduce the burden on the city and beautify the urban environment. In recent years, visual artists have focused their sustained attention and explora⁃tion on junk materials and forms. They have used the discarded products creatively and explored their common aes⁃thetic characteristics. Junk art permeates into and transforms these garbage objects, enabling them to have a new life. Besides, a series of unique artistic expressions exerts an important impact on contemporary art and life.

  5. Visualising "Junk" DNA through Bioinformatics

    Science.gov (United States)

    Elwess, Nancy L.; Latourelle, Sandra M.; Cauthorn, Olivia

    2005-01-01

    One of the hottest areas of science today is the field in which biology, information technology,and computer science are merged into a single discipline called bioinformatics. This field enables the discovery and analysis of biological data, including nucleotide and amino acid sequences that are easily accessed through the use of computers. As…

  6. Censorship and Junk Food Journalism.

    Science.gov (United States)

    Jensen, Carl

    1984-01-01

    Discusses journalistic phenomenon whereby Americans are inundated with same news with only names, dates, and locations changing. Highlights include news explosion, well-documented news, why "Ten Most Censored Stories" chosen by Project Censored (Sonoma State University, California) are not covered by major news media, federal policies,…

  7. The impact of Curtin University's activity, food and attitudes program on physical activity, sedentary time and fruit, vegetable and junk food consumption among overweight and obese adolescents: a waitlist controlled trial.

    Directory of Open Access Journals (Sweden)

    Leon M Straker

    Full Text Available BACKGROUND: To determine the effects of participation in Curtin University's Activity, Food and Attitudes Program (CAFAP, a community-based, family-centered behavioural intervention, on the physical activity, sedentary time, and healthy eating behaviours of overweight and obese adolescents. METHODS: In this waitlist controlled clinical trial in Western Australia, adolescents (n = 69, 71% female, mean age 14.1 (SD 1.6 years and parents completed an 8-week intervention followed by 12 months of telephone and text message support. Assessments were completed at baseline, before beginning the intervention, immediately following the intervention, and at 3-, 6-, and 12- months follow-up. The primary outcomes were physical activity and sedentary time assessed by accelerometers and servings of fruit, vegetables and junk food assessed by 3-day food records. RESULTS: During the intensive 8-week intervention sedentary time decreased by -5.1 min/day/month (95% CI: -11.0, 0.8 which was significantly greater than the rate of change during the waitlist period (p = .014. Moderate physical activity increased by 1.8 min/day/month (95% CI: -0.04, 3.6 during the intervention period, which was significantly greater than the rate of change during the waitlist period (p = .041. Fruit consumption increased during the intervention period (monthly incidence rate ratio (IRR 1.3, 95% CI: 1.10, 1.56 and junk food consumption decreased (monthly IRR 0.8, 95% CI: 0.74, 0.94 and these changes were different to those seen during the waitlist period (p = .004 and p = .020 respectively. CONCLUSIONS: Participating in CAFAP appeared to have a positive influence on the physical activity, sedentary and healthy eating behaviours of overweight and obese adolescents and many of these changes were maintained for one year following the intensive intervention. TRIAL REGISTRATION: Australia and New Zealand Clinical Trials Registry ACTRN12611001187932.

  8. The impact of Curtin University's activity, food and attitudes program on physical activity, sedentary time and fruit, vegetable and junk food consumption among overweight and obese adolescents: a waitlist controlled trial.

    Science.gov (United States)

    Straker, Leon M; Howie, Erin K; Smith, Kyla L; Fenner, Ashley A; Kerr, Deborah A; Olds, Tim S; Abbott, Rebecca A; Smith, Anne J

    2014-01-01

    To determine the effects of participation in Curtin University's Activity, Food and Attitudes Program (CAFAP), a community-based, family-centered behavioural intervention, on the physical activity, sedentary time, and healthy eating behaviours of overweight and obese adolescents. In this waitlist controlled clinical trial in Western Australia, adolescents (n = 69, 71% female, mean age 14.1 (SD 1.6) years) and parents completed an 8-week intervention followed by 12 months of telephone and text message support. Assessments were completed at baseline, before beginning the intervention, immediately following the intervention, and at 3-, 6-, and 12- months follow-up. The primary outcomes were physical activity and sedentary time assessed by accelerometers and servings of fruit, vegetables and junk food assessed by 3-day food records. During the intensive 8-week intervention sedentary time decreased by -5.1 min/day/month (95% CI: -11.0, 0.8) which was significantly greater than the rate of change during the waitlist period (p = .014). Moderate physical activity increased by 1.8 min/day/month (95% CI: -0.04, 3.6) during the intervention period, which was significantly greater than the rate of change during the waitlist period (p = .041). Fruit consumption increased during the intervention period (monthly incidence rate ratio (IRR) 1.3, 95% CI: 1.10, 1.56) and junk food consumption decreased (monthly IRR 0.8, 95% CI: 0.74, 0.94) and these changes were different to those seen during the waitlist period (p = .004 and p = .020 respectively). Participating in CAFAP appeared to have a positive influence on the physical activity, sedentary and healthy eating behaviours of overweight and obese adolescents and many of these changes were maintained for one year following the intensive intervention. Australia and New Zealand Clinical Trials Registry ACTRN12611001187932.

  9. 基于Symbian OS系统的垃圾短信过滤器设计与实现%Design and Realization of Junk SMS Filtering Based on Symbian OS

    Institute of Scientific and Technical Information of China (English)

    徐文权

    2012-01-01

    结合目前常用的垃圾短信过滤方法,将相似度理论与模糊聚类理论知识相结合,设计出了一款基于Symbian OS系统的手机垃圾短信过滤器。此过滤器与单一贝叶斯文本算法和k近邻算法过滤相比,在准确率、正确率和召回率三个指标上都有了一定程度的提高。%In common use to filter Junk SMS combining with calculate similitude and fuzzy clustering theory, this article is based on Symbian OS to design a mobile terminal on the spain of filter. By practical. This type of filter in accuracy, precision and recall is better,compared with singularity Bayes and k nearest neighborhood.

  10. Association between junk food consumption and fast-food outlet access near school among Quebec secondary-school children: findings from the Quebec Health Survey of High School Students (QHSHSS) 2010-11.

    Science.gov (United States)

    Cutumisu, Nicoleta; Traoré, Issouf; Paquette, Marie-Claude; Cazale, Linda; Camirand, Hélène; Lalonde, Benoit; Robitaille, Eric

    2017-04-01

    We investigated the association between junk food consumption at lunchtime (JCL) and fast-food outlet access near school among secondary-school children in Quebec. A geographic information system database was used to characterize the food environment around a sub-sample of 374 public schools in which 26 655 students were enrolled. The outcome variable was JCL during the previous week, dichotomized into low JCL (none or once) v. high JCL (twice or more). Access to fast-food outlets near school was assessed using an existing database of fast-food outlets in Quebec. Covariates included student (age, sex and self-rated perceived health), family (familial status and parental education) and school (urban/rural status and deprivation) variables. Hierarchical logistic regression models were employed for analyses using PROC GLIMMIX of SAS version 9.3. Province of Quebec, Canada. We used data from the Quebec Health Survey of High School Students (QHSHSS) 2010-11, a survey of secondary-school Quebec students. Exposure to two or more fast-food outlets within a radius of 750 m around schools was associated with a higher likelihood of excess JCL (OR=1·50; 95 % CI 1·28, 1·75), controlling for the characteristics of the students, their families and their schools. The food environment surrounding schools can constitute a target for interventions to improve food choices among secondary-school children living in the province of Quebec. Transforming environments around schools to promote healthy eating includes modifying zoning regulations that restrict access to fast-food outlets around schools.

  11. 北京市海淀区8~16岁儿童少年食用十类垃圾食品现况调查及影响因素分析%Study on factors related to top 10 junk food consumption at 8 to 16 years of age,in Haidian District of Beijing

    Institute of Scientific and Technical Information of China (English)

    朱淑萍; 丁越江; 鲁向锋; 王宏伟; 杨暮; 汪建秀; 晁晓东; 赵振

    2008-01-01

    Objective To study the current situation of ten types of junk food consumption (assessed by World Health Organization) among children and adolescent as well as the contributing factors in Haidian District, Beijing so as to provide evidence for developing preventive and control measures and interventions. Methods A questionnaire survey was conducted to investigate the consumption of ten types of junk food practices in 1019 children and adolescent aged 8-16 years in Beijing Haidian District. Results One month prior to the study, 97.50% of the children and adolescent had eaten at least one type of junk food and 15.88 % of them had eaten all types of them. Rates on having eaten deep fried food, pickled food,processed meat products, biscuits, coke or alike drinks, convenience/fast food, canned food, dried or preserved fruit, cold and sweet food, barbecue food etc. appeared to be 70.43%, 60.14%, 79.72%,64.24 % ,69.63 %, 78.72 %, 42.16 %, 51.95 %, 68.13 %, 60.14 % respectively. The rate on eaten more than once a day of these ten types were 26.95%, 36.88%, 34.84%, 32.97%, 27.40%, 28.18%,37.91% ,26.15 % ,37.39%, 22.10% respectively. The rates for "do not like" and "dislike" these ten types junk food were 10.96% ,27.42% ,7.08% ,12.11% ,6.56% ,6.59%, 17.80%, 13.59% ,3.42%,5.19% respectively. Most of the children and adolescent ate junk food mainly during breakfast at home.Most of the surveyed children and adolescent did not have correct idea on nutrition of junk food. They received the information of junk food mainly from sources as advertisement on TV (67.95%), mother (9.02%), newspaper or magazines ( 6.71% ). Many factors, such as individual factors ( including physiological and psychological situations), social factors, family factors and the characteristics of food contributed to the eating junk food practiees of children and adolescent. Conclusion Eating junk food is a popular event among children and adolescent in Beijing Haidian District. Education strategies on

  12. [Junk food revolution or the cola colonization].

    Science.gov (United States)

    Horinger, P; Imoberdorf, R

    2000-03-01

    In ancient times, the main problem was to get food. Nowadays the difficulty is to decide for or against some foodstuff. In industrialized countries, this abundance led to the fact that people eat differently from what they should. Traditional populations were subject to periods of feast and famine. Those with a metabolism which stored energy with high energetic efficiency had a survival advantage. This is called the 'thrifty' genotype hypothesis. With the secured supply of calories, coupled with a sedentary lifestyle, the thrifty genotype becomes disadvantageous, causing obesity. Industrialization or 'cola-colonization' also leads to a dramatic increase in obesity and non-insulin dependent diabetes mellitus in developing countries. The spread of fast food restaurants all over the world has changed modern nutrition fundamentally. Influence begins early in childhood. Advertising concentrates on the selling of image over substance. However, fast food contains high levels of fat, especially trans fatty acids. Higher consumption of trans fatty acids was associated with a higher incidence of and mortality from coronary heart disease.

  13. Don't Eat Junk Food%Don't Eat Junk Food

    Institute of Scientific and Technical Information of China (English)

    何苗

    2012-01-01

    译文:吃过晚饭彼得和妈妈去购物。他们买了一些黄瓜和矿泉水。彼得想吃一个热狗和一个汉堡包。但妈妈说:“不要吃垃圾食品,不然你得去看医生了。”

  14. Digital junk: food and beverage marketing on Facebook.

    Science.gov (United States)

    Freeman, Becky; Kelly, Bridget; Baur, Louise; Chapman, Kathy; Chapman, Simon; Gill, Tim; King, Lesley

    2014-12-01

    We assessed the amount, reach, and nature of energy-dense, nutrient-poor (EDNP) food and beverage marketing on Facebook. We conducted a content analysis of the marketing techniques used by the 27 most popular food and beverage brand Facebook pages in Australia. We coded content across 19 marketing categories; data were collected from the day each page launched (mean = 3.65 years of activity per page). We analyzed 13 international pages and 14 Australian-based brand pages; 4 brands (Subway, Coca-Cola, Slurpee, Maltesers) had both national and international pages. Pages widely used marketing features unique to social media that increase consumer interaction and engagement. Common techniques were competitions based on user-generated content, interactive games, and apps. Four pages included apps that allowed followers to place an order directly through Facebook. Adolescent and young adult Facebook users appeared most receptive to engaging with this content. By using the interactive and social aspects of Facebook to market products, EDNP food brands capitalize on users' social networks and magnify the reach and personal relevance of their marketing messages.

  15. Junk-Time Junkies: An Emerging Addiction among Students.

    Science.gov (United States)

    Soper, W. Barlow; Miller, Mark J.

    1983-01-01

    Discusses video games as an emerging addiction among students. Describes the appeal of the games, their impact on students, and measures passed in some cities to curb adolescent involvement. Counselors must be prepared to anticipate and ameliorate potentially negative side effects. (JAC)

  16. Gambling advocacy: lessons from tobacco, alcohol and junk food.

    Science.gov (United States)

    Thomas, Samantha L; David, Jennifer; Randle, Melanie; Daube, Mike; Senior, Kate

    2016-06-01

    To explore the attitudes and opinions of public health experts in gambling and related unhealthy commodity industries towards the tactics used by the gambling industry to prevent reform and the advocacy responses to these tactics. In-depth interviews (30-60 minutes) with a convenience sample of 15 public health experts and stakeholders with a public health approach to gambling (n=10), or other unhealthy commodity industries (food, alcohol, tobacco, n=5). Participants described the influences of political lobbying and donations on public policy, and industry framing of problem gambling as an issue of personal responsibility. Industry funding of, and influence over, academic research was considered to be one of the most effective industry tactics to resist reform. Participants felt there was a need to build stronger coalitions and collaborations between independent academics, and to improve the utilisation of media to more effectively shift perceptions of gambling harm away from the individual and towards the product. Gambling industry tactics are similar to the tactics of other unhealthy commodity industries. However, advocacy initiatives to counter these tactics in gambling are less developed than in other areas. The formation of national public health coalitions, as well as a strong evidence base regarding industry tactics, will help to strengthen advocacy initiatives. © 2015 Public Health Association of Australia.

  17. Got junk? The federal role in regulating "competitive" foods.

    Science.gov (United States)

    Salinsky, Eileen

    2009-12-11

    A wide variety of food and beverage items are available in schools in addition to the school meals provided through the National School Lunch Program and School Breakfast Program. A long-standing source of controversy, the need for stronger federal restrictions on foods that compete with school meals is again under debate. This issue brief examines the availability and consumption of competitive foods, explores the regulation of these foods at the federal level, considers trends in state and local restrictions, and summarizes perceived barriers to improving the nutritional quality of competitive food options.

  18. Mammalian Introns: When the Junk Generates Molecular Diversity

    Directory of Open Access Journals (Sweden)

    Florent Hubé

    2015-02-01

    Full Text Available Introns represent almost half of the human genome, yet their vast majority is eliminated from eukaryotic transcripts through RNA splicing. Nevertheless, they feature key elements and functions that deserve further interest. At the level of DNA, introns are genomic segments that can shelter independent transcription units for coding and non-coding RNAs which transcription may interfere with that of the host gene, and regulatory elements that can influence gene expression and splicing itself. From the RNA perspective, some introns can be subjected to alternative splicing. Intron retention appear to provide some plasticity to the nature of the protein produced, its distribution in a given cell type and timing of its translation. Intron retention may also serve as a switch to produce coding or non-coding RNAs from the same transcription unit. Conversely, splicing of introns has been directly implicated in the production of small regulatory RNAs. Hence, splicing of introns also appears to provide plasticity to the type of RNA produced from a genetic locus (coding, non-coding, short or long. We addressed these aspects to add to our understanding of mechanisms that control the fate of introns and could be instrumental in regulating genomic output and hence cell fate.

  19. Digital Junk: Food and Beverage Marketing on Facebook

    Science.gov (United States)

    Freeman, Becky; Kelly, Bridget; Baur, Louise; Chapman, Kathy; Chapman, Simon; Gill, Tim; King, Lesley

    2014-01-01

    Objectives. We assessed the amount, reach, and nature of energy-dense, nutrient-poor (EDNP) food and beverage marketing on Facebook. Methods. We conducted a content analysis of the marketing techniques used by the 27 most popular food and beverage brand Facebook pages in Australia. We coded content across 19 marketing categories; data were collected from the day each page launched (mean = 3.65 years of activity per page). Results. We analyzed 13 international pages and 14 Australian-based brand pages; 4 brands (Subway, Coca-Cola, Slurpee, Maltesers) had both national and international pages. Pages widely used marketing features unique to social media that increase consumer interaction and engagement. Common techniques were competitions based on user-generated content, interactive games, and apps. Four pages included apps that allowed followers to place an order directly through Facebook. Adolescent and young adult Facebook users appeared most receptive to engaging with this content. Conclusions. By using the interactive and social aspects of Facebook to market products, EDNP food brands capitalize on users’ social networks and magnify the reach and personal relevance of their marketing messages. PMID:25322294

  20. Irradiated foodstuff: atom, junk-food and globalization; Aliments irradies: Atome, malbouffe et mondialisation

    Energy Technology Data Exchange (ETDEWEB)

    Azam, Genevieve; Berlan, Jean-Pierre; Desbordes, Roland; Dufour, Francois; Fievet, Yann; Folliard, Thierry; Gallais, Veronique; Hauter, Wenonah; Jacquiau, Christian; Kastler, Guy; Lannoye, Paul; Le Goff, Lylian; Le Rohellec, Catherine; Louchard, Olivier; Marechal, Gilles; Nicolas, Yveline; Remesy, Christian; Trouve, Aurelie; Veillerette, Francois

    2008-07-01

    Food irradiation is officially presented as an ideal technology at the service of worldwide health safety and as an alternative to chemical processing of foodstuff. It is first of all a multi-usage technology for the preservation, disinfestation, ripening slowing down, and germination inhibition of products which serves the interests of multinational companies of the agriculture and food industry. According to the authors, it is also an instrument for the globalization of foodstuff trade encouraged by the international institutions and by some governments. The book stresses on the health, socio-economic and environmental risks of this technology: vitamins loss, carcinogenesis, mutagenesis, impact on local employment and economy, risks linked with the use of irradiation devices etc

  1. 28 CFR 25.56 - Responsibilities of junk yards and salvage yards and auto recyclers.

    Science.gov (United States)

    2010-07-01

    .... (h) Scrap metal processors and shredders that receive automobiles for recycling where the condition... supplier's compliance with NMVTIS cannot be ascertained, however, scrap metal processors and shredders must... determined based on this inspection, scrap metal processors and shredders may rely on primary...

  2. From "junk" to gene: curriculum vitae of a primate receptor isoform gene.

    Science.gov (United States)

    Singer, Silke S; Männel, Daniela N; Hehlgans, Thomas; Brosius, Jürgen; Schmitz, Jürgen

    2004-08-20

    Exonization of Alu retroposons awakens public opinion, particularly when causing genetic diseases. However, often neglected, alternative "Alu-exons" also carry the potential to greatly enhance genetic diversity by increasing the transcriptome of primates chiefly via alternative splicing.Here, we report a 5' exon generated from one of the two alternative transcripts in human tumor necrosis factor receptor gene type 2 (p75TNFR) that contains an ancient Alu-SINE, which provides an alternative N-terminal protein-coding domain. We follow the primate evolution over the past 63 million years to reconstruct the key events that gave rise to a novel receptor isoform. The Alu integration and start codon formation occurred between 58 and 40 million years ago (MYA) in the common ancestor of anthropoid primates. Yet a functional gene product could not be generated until a novel splice site and an open reading frame were introduced between 40 and 25 MYA on the catarrhine lineage (Old World monkeys including apes).

  3. Where do food desert residents buy most of their junk food? Supermarkets.

    Science.gov (United States)

    Vaughan, Christine A; Cohen, Deborah A; Ghosh-Dastidar, Madhumita; Hunter, Gerald P; Dubowitz, Tamara

    2017-10-01

    To examine where residents in an area with limited access to healthy foods (an urban food desert) purchased healthier and less healthy foods. Food shopping receipts were collected over a one-week period in 2013. These were analysed to describe where residents shopped for food and what types of food they bought. Two low-income, predominantly African-American neighbourhoods with limited access to healthy foods in Pittsburgh, PA, USA. Two hundred and ninety-three households in which the primary food shoppers were predominantly female (77·8 %) and non-Hispanic black (91·1 %) adults. Full-service supermarkets were by far the most common food retail outlet from which food receipts were returned and accounted for a much larger proportion (57·4 %) of food and beverage expenditures, both healthy and unhealthy, than other food retail outlets. Although patronized less frequently, convenience stores were notable purveyors of unhealthy foods. Findings highlight the need to implement policies that can help to decrease unhealthy food purchases in full-service supermarkets and convenience stores and increase healthy food purchases in convenience stores.

  4. Protecting young people from junk food advertising: implications of psychological research for First Amendment law

    National Research Council Canada - National Science Library

    Harris, Jennifer L; Graff, Samantha K

    2012-01-01

    In the United States, one third of children and adolescents are overweight or obese, yet food and beverage companies continue to target them with advertising for products that contribute to this obesity crisis...

  5. Adolescent Girls’ Most Common Source of Junk Food Away from Home: Someone Else’s House

    Science.gov (United States)

    Cohen, Deborah A.; Dastidar, Bonnie Ghosh; Beckman, Robin; Lytle, Leslie; Elder, John; Pereira, Mark A.; Mortenson, Sara Veblen; Pickrel, Julie; Conway, Terry L.

    2013-01-01

    Contextual factors associated with adolescent girls’ dietary behaviors could inform future interventions to improve diet. High school girls completed a 7-day diary, recording all trips made. In places other than home or school they recorded the food eaten. Girls made an average of 11.4 trips per week other than home or school. Snacks high in solid oils, fats and added sugars (SOFAS) were frequently consumed. Girls reported eating an average of 3.5 servings per week of snacks high in SOFAS at someone else’s house compared to 3.0 servings per week at retail food outlets. Findings demonstrate that low nutrient foods are ubiquitous and efforts should be made to reduce their availability in multiple settings. PMID:22818589

  6. Roles of “junk phosphorylation” in modulating biomolecular association of phosphorylated proteins?

    DEFF Research Database (Denmark)

    Tan, Chris Soon Heng; Jørgensen, Claus; Linding, Rune

    2010-01-01

    Protein phosphorylation dynamically regulates cellular activities in response to environmental cues. Sequence conservation analysis of recent proteome-wide phosphorylation data revealed that many previously unidentified phosphorylation sites are not well-conserved leading to the proposal that man...... evolutionary approaches to interpret physiological important sites....

  7. Space Junk Norms: US Advantages in Creating a Debris Reducing Outer Space Norm

    Science.gov (United States)

    2011-05-01

    represented by the debate over space weaponization. Stephen Krasner defines norms as “standards of behavior defined in terms of rights and...designer of the 20 Stephen Clark, “Air Force Spaceplane is an Odd Bird with a Twisted Path...the Sea. New., rev. ed. Manchester: University Press, 1988. Clark, Stephen . “Air Force Spaceplane is an Odd Bird with a Twisted Path,” Space.com, 2

  8. Interaction Junk: User Interaction-Based Evaluation of Visual Analytic Systems

    Energy Technology Data Exchange (ETDEWEB)

    Endert, Alexander; North, Chris

    2012-10-14

    With the growing need for visualization to aid users in understanding large, complex datasets, the ability for users to interact and explore these datasets is critical. As visual analytic systems have advanced to leverage powerful computational models and data analytics capabilities, the modes by which users engage and interact with the information are limited. Often, users are taxed with directly manipulating parameters of these models through traditional GUIs (e.g., using sliders to directly manipulate the value of a parameter). However, the purpose of user interaction in visual analytic systems is to enable visual data exploration – where users can focus on their task, as opposed to the tool or system. As a result, users can engage freely in data exploration and decision-making, for the purpose of gaining insight. In this position paper, we discuss how evaluating visual analytic systems can be approached through user interaction analysis, where the goal is to minimize the cognitive translation between the visual metaphor and the mode of interaction (i.e., reducing the “Interactionjunk”). We motivate this concept through a discussion of traditional GUIs used in visual analytics for direct manipulation of model parameters, and the importance of designing interactions the support visual data exploration.

  9. Protecting young people from junk food advertising: implications of psychological research for First Amendment law.

    Science.gov (United States)

    Harris, Jennifer L; Graff, Samantha K

    2012-02-01

    In the United States, one third of children and adolescents are overweight or obese, yet food and beverage companies continue to target them with advertising for products that contribute to this obesity crisis. When government restrictions on such advertising are proposed, the constitutional commercial speech doctrine is often invoked as a barrier to action. We explore incongruities between the legal justifications for the commercial speech doctrine and the psychological research on how food advertising affects young people. A proper interpretation of the First Amendment should leave room for regulations to protect young people from advertising featuring calorie-dense, nutrient-poor foods and beverages.

  10. Junk food packaging on healthy food: A matter of children’s perceptions

    OpenAIRE

    Pires, Carla Sofia Gomes

    2011-01-01

    A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics While there is extensive research regarding the impact of television on food choices, much less is focused on an instrument able to change beliefs at the point-of-purchase: packaging. This study aims to understand how food packaging can influence children‟s attitudes and purchase decisions towards healthier choices. Therefore, the appealing ...

  11. Adolescent girls' most common source of junk food away from home.

    Science.gov (United States)

    Cohen, Deborah A; Ghosh-Dastidar, Bonnie; Beckman, Robin; Lytle, Leslie; Elder, John; Pereira, Mark A; Veblen Mortenson, Sara; Pickrel, Julie; Conway, Terry L

    2012-09-01

    Contextual factors associated with adolescent girls' dietary behaviors could inform future interventions to improve diet. High school girls completed a 7-day diary, recording all trips made. In places other than home or school they recorded the food eaten. Girls made an average of 11.4 trips per week other than to home or school. Snacks high in solid oils, fats and added sugars (SOFAS) were frequently consumed. Girls reported eating an average of 3.5 servings per week of snacks high in SOFAS at someone else's house compared to 3.0 servings per week at retail food outlets. Findings demonstrate that low nutrient foods are ubiquitous and efforts should be made to reduce their availability in multiple settings. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. The American Education Diet: Can U.S. Students Survive on Junk Food?

    Science.gov (United States)

    DeSchryver, Dave

    U.S. student scores in science compare unfavorably with those of other nations, and other standardized test scores by U.S. students are also comparatively lower. Polls of parents indicate dissatisfaction with U.S. education. College teachers and employers feel that high school graduates are weak in skills. This document offers negative perceptions…

  13. Here's Why Junk Food Still Is on Sale at Some Schools.

    Science.gov (United States)

    Nolte, M. Chester

    1984-01-01

    A 1983 federal appeals court decision says the Secretary of Agriculture cannot establish time and place restrictions on the sale of snack items in schools. If snack items are to be banned from schools, the School Lunch Act must be reworded. (MD)

  14. Junk DNA and the long non-coding RNA twist in cancer genetics

    NARCIS (Netherlands)

    H. Ling (Hui); K. Vincent; M. Pichler; R. Fodde (Riccardo); I. Berindan-Neagoe (Ioana); F.J. Slack (Frank); G.A. Calin (George)

    2015-01-01

    textabstractThe central dogma of molecular biology states that the flow of genetic information moves from DNA to RNA to protein. However, in the last decade this dogma has been challenged by new findings on non-coding RNAs (ncRNAs) such as microRNAs (miRNAs). More recently, long non-coding RNAs (lnc

  15. The "False Memory" Defense: Using Disinformation and Junk Science In and Out of Court.

    Science.gov (United States)

    Whitfield, Charles L.

    2001-01-01

    Describes a seemingly sophisticated, but mostly contrived and often erroneous "false memory" defense, and compares it in a brief review to what the science says about the effect of trauma on memory. Each of 22 of the more commonly used components of this defense is described and discussed with respect to what the science says about them.…

  16. The "False Memory" DefenseUsing Disinformation and Junk Science In and Out of Court.

    Science.gov (United States)

    Whitfield, C L

    2000-01-01

    This article describes a seemingly sophisticated, but mostly contrived and often erroneous “false memory” defense, and compares it in a brief review to what the science says about the effect of trauma on memory. Child sexual abuse is widespread and dissociative/traumatic amnesia for it is common. Accused, convicted and self-confessed child molesters and their advocates have crafted a strategy that tries to negate their abusive, criminal behavior, which we can call a “false memory” defense. Each of 22 of the more commonly used components of this defense is described and discussed with respect to what the science says about them. Armed with this knowledge, survivors, their clinicians, and their attorneys will be better able to refute this defense of disinformation.

  17. More apples less chips? The effect of school fruit schemes on the consumption of junk food

    OpenAIRE

    Brunello, Giorgio; Paola, Maria de; Labartino, Giovanna

    2012-01-01

    We use scanner data of supermarket sales to investigate the effects of the EU School Fruit campaign, conducted in a sample of primary schools in the city of Rome during 2010 and 2011, on the consumption of unhealthy snacks. We allocate supermarkets to treatment and control groups depending on whether they are located or not near treated schools and estimate the causal effect of the program by comparing the changes in the sales of snacks in treated stores with the changes in control stores. We...

  18. Wideband Global SATCOM (WGS)

    Science.gov (United States)

    2015-12-01

    SATCOM (WGS), previously reported as Wideband Gapfiller Satellites, is a constellation of the Department of Defense’s highest capacity communication...has two International Partnerships. In exchange for access to a portion of the WGS constellation , Australia is providing funds for WGS-6 while Canada...48 UNCLASSIFIED 6 Executive Summary Wideband Global SATCOM (WGS), previously reported as Wideband Gapfiller Satellites, is a constellation of the

  19. The effect of pyrolytic carbon black prepared from junked tires on the properties of ethylene-propylene-diene copolymers (EPDM

    Directory of Open Access Journals (Sweden)

    2009-05-01

    Full Text Available Pyrolytic carbon black (PCB made from used tires was used in ethylene-propylene-diene copolymers (EPDM. The microstructure of PCB was characterized by scanning electron microscopy (SEM. PCB was compounded with EPDM to prepare EPDM vulcanizates. The effects of PCB on the processing properties of EPDM compounds and the mechanical properties of vulcanizates were investigated and compared with other traditional fillers such as semi-reinforcing furnace black (N774, light calcium carbonate (CaCO3 and thermal black (N990. At the same time, the rheological behavior of EPDM compounds filled with different fillers was characterized by capillary rheometrics. The SEM photos showed that the particle shape was quiet different from that of CaCO3 and N990, it was similar to that of N774. The primary particle size was smaller than that of N774, but the aggregate size of PCB was larger than that of N774. The effect of PCB on the processing properties of EPDM compounds was similar to that of other fillers. Among the four fillers, PCB imparted EPDM compounds with higher Mooney viscosity. With the increase of filler content, the scorch time and optimum curing time of EPDM compounds changed little. The reinforcing effect of PCB was similar to that of N990, but inferior to that of N774. With the increase of PCB content, tensile strength, tear strength, and modulus at 100% elongation of EPDM vulcanizates increased significantly. When EPDM was filled with 50 phr PCB, the tear strength of EPDM vulcanizates increased by 3 times, compared with that of EPDM gum vulcanizates. The appearance of EPDM extrudate filled with PCB was coarser than that of other fillers.

  20. "垃圾短信"的界定与规制%Definition and Regulation of "Junk Short Text Messages"

    Institute of Scientific and Technical Information of China (English)

    吴伟光

    2008-01-01

    @@ 从2006年下半年开始,以栏目为代表的一些主要媒体开始连续针对"垃圾短信"的有关情况进行报道,[1]使得足否应该以及如何对垃圾短信进行规制成为一个引人关注的问题.但是垃圾短信与短信广告应该是不同的概念.

  1. Contexts paired with junk food impair goal-directed behaviour in rats: implications for decision making in obesogenic environments

    Directory of Open Access Journals (Sweden)

    Michael D. Kendig

    2016-11-01

    Full Text Available The high prevalence of obesity and related metabolic diseases calls for greater understanding of the factors that drive excess energy intake. Calorie-dense palatable foods are readily available and often are paired with highly salient environmental cues. These cues can trigger food-seeking and consumption in the absence of hunger. Here we examined the effects of palatable food-paired environmental cues on control of instrumental food-seeking behaviour. In Experiment 1, adult male rats received exposures to one context containing three ‘junk’ foods (JF context and another containing chow (Chow context. Next, rats were food-deprived and trained to perform instrumental responses (lever-press for two novel food rewards in a third, distinct context. Contextual influences on flexible control of food-seeking behaviour were then assessed by outcome devaluation tests held in the JF, chow, and training contexts. Devaluation was achieved using specific satiety and test order was counterbalanced. Rats exhibited goal-directed control over behaviour when tested in the training and chow-paired contexts. Notably, performance was habitual (insensitive to devaluation when tested in the JF context. In Experiment 2 we tested whether the impairment found in the JF context could be ameliorated by the presentation of a discrete auditory cue paired with the chow context, relative to a second cue paired with the JF context. Consistent with the results of Experiment 1, the devaluation effect was not significant when rats were tested in the JF context with the JF cue. However, presenting the chow cue increased the impact of the devaluation treatment leading to a robust devaluation effect. Further tests confirmed that performance in the chow context was goal-directed and that sensory-specific satiety in the JF context was intact. These results show that environments paired with palatable foods can impair goal-directed control over food-seeking behaviour, but that this deficit was improved by a cue paired with chow. This has promising implications for assisting individuals in controlling their eating behaviour in environments designed to dysregulate it.

  2. Realities of biomedical product liability suits and the role of junk science: from breast implants to TASER weapons.

    Science.gov (United States)

    Kroll, Mark

    2012-01-01

    In the summer of 2006, manufacturers of a simple respirator mask costing US$1 told the U.S. Congress that Americans would find a shortage of these masks if there was another flu pandemic. The reason for this was that suing the makers of these dust masks became a major business for trial lawyers. By 2006, there had been more than 326,000 lawsuits filed. It has been reported in many cases that the law firms worked with cooperative physicians and contracted with X-ray labs to screen individuals for lung problems. If an individual had an abnormal lung X-ray and claimed that they had used a certain brand of respirator and the manufacturer was still in business and had economic resourcesa lawsuit was filed. Some manufacturers went out of business while others simply stopped making the masks.

  3. Junk food or genuine nourishment: The nutritional value of some of South African fast-food chains

    Directory of Open Access Journals (Sweden)

    R.C. Van den Honert

    2003-12-01

    Full Text Available Integer programming is used to test the nutritional completeness of two fast-food chains operating in South Africa. McDonald's and Kentucky Fried Chicken. It is shown that a fully nutritional and varied daily diet can be made up from McDonald's menu items, but the same is not true for Kentucky Fried Chicken. This exercise is highly suited to introduce students to mathematical programming: skills learned include formulating mathematical programming problems, mastering linear programming software and exploring the Internet for relevant data.

  4. Junk food or genuine nourishment: The nutritional value of some of South African fast-food chains

    OpenAIRE

    R.C. Van den Honert

    2003-01-01

    Integer programming is used to test the nutritional completeness of two fast-food chains operating in South Africa. McDonald's and Kentucky Fried Chicken. It is shown that a fully nutritional and varied daily diet can be made up from McDonald's menu items, but the same is not true for Kentucky Fried Chicken. This exercise is highly suited to introduce students to mathematical programming: skills learned include formulating mathematical programming problems, mastering linear programming softwa...

  5. "Most of Them Are Junk Food but We Did Put Fruit on There and We Have Water"

    Science.gov (United States)

    Waddingham, Suzanne; Stevens, Stella; Macintyre, Kate; Shaw, Kelly

    2015-01-01

    Purpose: The Australian Dietary Guidelines support good health and disease prevention. Children with healthy eating habits established early in life have been shown to continue these habits into adulthood compared with those children who have poor eating habits in their younger years. The nutritional intake of many Australian children is not in…

  6. How avatar customizability affects children's arousal and subjective presence during junk food-sponsored online video games.

    Science.gov (United States)

    Bailey, Rachel; Wise, Kevin; Bolls, Paul

    2009-06-01

    The purpose of this study was to determine how children cognitively and emotionally process interactive marketing of snack food products in advergames. Children (N = 30) aged 10 to 12 were asked to play advergames with (a) avatars that were assigned to them, (b) avatars chosen from a pool, and (c) self-designed avatars. The children's skin conductance levels were collected during play. After gameplay, at each customization level, self-reported presence was collected. The results of this study indicate that customization of game avatars can affect both subjective feelings of presence and psychophysiological indicators of emotion during gameplay, which may make the gameplay experience more enjoyable. This may have implications for game sponsors and producers. Self-reported presence had no effect on psychophysiological indicators of emotion during gameplay. Implications of this finding and limitations of this study are discussed.

  7. Identifying sources of children's consumption of junk food in Boston after-school programs, April-May 2011.

    Science.gov (United States)

    Kenney, Erica L; Austin, S Bryn; Cradock, Angie L; Giles, Catherine M; Lee, Rebekka M; Davison, Kirsten K; Gortmaker, Steven L

    2014-11-20

    Little is known about how the nutrition environment in after-school settings may affect children's dietary intake. We measured the nutritional quality of after-school snacks provided by programs participating in the National School Lunch Program or the Child and Adult Care Food Program and compared them with snacks brought from home or purchased elsewhere (nonprogram snacks). We quantified the effect of nonprogram snacks on the dietary intake of children who also received program-provided snacks during after-school time. Our study objective was to determine how different sources of snacks affect children's snack consumption in after-school settings. We recorded snacks served to and brought in by 298 children in 18 after-school programs in Boston, Massachusetts, on 5 program days in April and May 2011. We measured children's snack consumption on 2 program days using a validated observation protocol. We then calculated within-child change-in-change models to estimate the effect of nonprogram snacks on children's dietary intake after school. Nonprogram snacks contained more sugary beverages and candy than program-provided snacks. Having a nonprogram snack was associated with significantly higher consumption of total calories (+114.7 kcal, P foods with added sugars (+0.5 servings; P foods and nearly twice as many calories than on days when they consumed only program-provided snacks. Policy strategies limiting nonprogram snacks or setting nutritional standards for them in after-school settings should be explored further as a way to promote child health.

  8. "Most of Them Are Junk Food but We Did Put Fruit on There and We Have Water"

    Science.gov (United States)

    Waddingham, Suzanne; Stevens, Stella; Macintyre, Kate; Shaw, Kelly

    2015-01-01

    Purpose: The Australian Dietary Guidelines support good health and disease prevention. Children with healthy eating habits established early in life have been shown to continue these habits into adulthood compared with those children who have poor eating habits in their younger years. The nutritional intake of many Australian children is not in…

  9. Contexts Paired with Junk Food Impair Goal-Directed Behavior in Rats: Implications for Decision Making in Obesogenic Environments

    Science.gov (United States)

    Kendig, Michael D.; Cheung, Ambrose M. K.; Raymond, Joel S.; Corbit, Laura H.

    2016-01-01

    The high prevalence of obesity and related metabolic diseases calls for greater understanding of the factors that drive excess energy intake. Calorie-dense palatable foods are readily available and often are paired with highly salient environmental cues. These cues can trigger food-seeking and consumption in the absence of hunger. Here we examined the effects of palatable food-paired environmental cues on control of instrumental food-seeking behavior. In Experiment 1, adult male rats received exposures to one context containing three “junk” foods (JFs context) and another containing chow (Chow context). Next, rats were food-deprived and trained to perform instrumental responses (lever-press) for two novel food rewards in a third, distinct context. Contextual influences on flexible control of food-seeking behavior were then assessed by outcome devaluation tests held in the JF, chow and training contexts. Devaluation was achieved using specific satiety and test order was counterbalanced. Rats exhibited goal-directed control over behavior when tested in the training and chow-paired contexts. Notably, performance was habitual (insensitive to devaluation) when tested in the JF context. In Experiment 2 we tested whether the impairment found in the JF context could be ameliorated by the presentation of a discrete auditory cue paired with the chow context, relative to a second cue paired with the JF context. Consistent with the results of Experiment 1, the devaluation effect was not significant when rats were tested in the JF context with the JF cue. However, presenting the chow cue increased the impact of the devaluation treatment leading to a robust devaluation effect. Further tests confirmed that performance in the chow context was goal-directed and that sensory-specific satiety in the JF context was intact. These results show that environments paired with palatable foods can impair goal-directed control over food-seeking behavior, but that this deficit was improved by a cue paired with chow. This has promising implications for assisting individuals in controlling their eating behavior in environments designed to dysregulate it. PMID:27877118

  10. Generalized Wideband Cyclic MUSIC

    Directory of Open Access Journals (Sweden)

    Zhang-Meng Liu

    2009-01-01

    Full Text Available The method of Spectral Correlation-Signal Subspace Fitting (SC-SSF fails to separate wideband cyclostationary signals with coherent second-order cyclic statistics (SOCS. Averaged Cyclic MUSIC (ACM method made up for the drawback to some degree via temporally averaging the cyclic cross-correlation of the array output. This paper interprets ACM from another perspective and proposes a new DOA estimation method by generalizing ACM for wideband cyclostationary signals. The proposed method successfully makes up for the aforementioned drawback of SC-SSF and obtains a more satisfying performance than ACM. It is also demonstrated that ACM is a simplified form of the proposed method when only a single spectral frequency is exploited, and the integration of the frequencies within the signal bandwidth helps the new method to outperform ACM.

  11. Ultra-Wideband Radio

    Directory of Open Access Journals (Sweden)

    Won Namgoong

    2005-03-01

    Full Text Available The application of ultra-wideband (UWB technology to low-cost short-range communications presents unique challenges to the communications engineer. The impact of the US FCC's regulations and the characteristics of the low-power UWB propagation channels are explored, and their effects on UWB hardware design are illustrated. This tutorial introduction includes references to more detailed explorations of the subject.

  12. Wideband amplifier design

    CERN Document Server

    Hollister, Allen L

    2007-01-01

    In this book, the theory needed to understand wideband amplifier design using the simplest models possible will be developed. This theory will be used to develop algebraic equations that describe particular circuits used in high frequency design so that the reader develops a ""gut level"" understanding of the process and circuit. SPICE and Genesys simulations will be performed to show the accuracy of the algebraic models. By looking at differences between the algebraic equations and the simulations, new algebraic models will be developed that include parameters originally left out of the model

  13. Wideband CMOS receivers

    CERN Document Server

    Oliveira, Luis

    2015-01-01

    This book demonstrates how to design a wideband receiver operating in current mode, in which the noise and non-linearity are reduced, implemented in a low cost single chip, using standard CMOS technology.  The authors present a solution to remove the transimpedance amplifier (TIA) block and connect directly the mixer’s output to a passive second-order continuous-time Σ∆ analog to digital converter (ADC), which operates in current-mode. These techniques enable the reduction of area, power consumption, and cost in modern CMOS receivers.

  14. Maritime wideband communication networks video transmission scheduling

    CERN Document Server

    Yang, Tingting

    2014-01-01

    This Springer Brief covers emerging maritime wideband communication networks and how they facilitate applications such as maritime distress, urgency, safety and general communications. It provides valuable insight on the data transmission scheduling and protocol design for the maritime wideband network. This brief begins with an introduction to maritime wideband communication networks including the architecture, framework, operations and a comprehensive survey on current developments. The second part of the brief presents the resource allocation and scheduling for video packet transmission wit

  15. Wideband Piezomagnetoelastic Vibration Energy Harvesting

    DEFF Research Database (Denmark)

    Lei, Anders; Thomsen, Erik Vilain

    2014-01-01

    This work presents a small-scale wideband piezomagnetoelastic vibration energy harvester (VEH) aimed for operation at frequencies of a few hundred Hz. The VEH consists of a tape-casted PZT cantilever with thin sheets of iron foil attached on each side of the free tip. The wideband operation...... softening effect. In linear operation (without magnets) the harvester generates a RMS power of 141 μW/g2 at 588 Hz with a relative bandwidth of 3.8% over a 100 kΩ load resistor. When operated with one magnet ideally positioned opposite the cantilever, a RMS power of 265 μW/g2 is generated at 270 Hz...

  16. Eating ‘Junk-Food' Produces Rapid and Long-Lasting Increases in NAc CP-AMPA Receptors: Implications for Enhanced Cue-Induced Motivation and Food Addiction

    OpenAIRE

    Oginsky, Max F; Goforth, Paulette B.; Nobile, Cameron W; Lopez-Santiago, Luis F.; Ferrario, Carrie R

    2016-01-01

    Urges to eat are influenced by stimuli in the environment that are associated with food (food cues). Obese people are more sensitive to food cues, reporting stronger craving and consuming larger portions after food cue exposure. The nucleus accumbens (NAc) mediates cue-triggered motivational responses, and activations in the NAc triggered by food cues are stronger in people who are susceptible to obesity. This has led to the idea that alterations in NAc function similar to those underlying dr...

  17. Nourishing change. Partnership enlists dozens of hospitals to put healthier food on their menus and kick junk food out of the cafeteria.

    Science.gov (United States)

    Lee, Jaimy

    2012-10-08

    More than 150 hospitals have signed on to the Partnership for a Healthier America's push to ditch the deep-fat fryer in their cafeterias and bulk up on fruit and veggies. "Our focus is to ensure that if people want to make a healthy choice, they can," says Larry Soler, left, president and CEO of the partnership, which is working to reduce childhood obesity.

  18. Eating ‘Junk-Food' Produces Rapid and Long-Lasting Increases in NAc CP-AMPA Receptors: Implications for Enhanced Cue-Induced Motivation and Food Addiction

    OpenAIRE

    Oginsky, Max F.; Goforth, Paulette B.; Nobile, Cameron W.; Lopez-Santiago, Luis F.; Ferrario, Carrie R.

    2016-01-01

    Urges to eat are influenced by stimuli in the environment that are associated with food (food cues). Obese people are more sensitive to food cues, reporting stronger craving and consuming larger portions after food cue exposure. The nucleus accumbens (NAc) mediates cue-triggered motivational responses, and activations in the NAc triggered by food cues are stronger in people who are susceptible to obesity. This has led to the idea that alterations in NAc function similar to those underlying dr...

  19. The regional price of junk foods relative to healthy foods in the UK: indirect estimation of a time series, 1997-2009

    OpenAIRE

    Capacci, Sara; Mazzocchi, Mario; Shankar, Bhavani

    2012-01-01

    The paper aims at indirectly estimating a time series of food prices from household expenditure data, focusing on foods considered as ‘junk’ relative to healthy foods. The “big 6” among the HFSS (high in fats, sugar and salt) foods identified by the Food Standard Agency have been selected to compose a target ‘unhealthy’ basket, compared to a ‘healthy’ benchmark aggregate including fruit and vegetables. UK data from the National Food Surveys, the Household Expenditure Surveys and the Living Co...

  20. Socioeconomic indicators and frequency of traditional food, junk food, and fruit and vegetable consumption amongst Inuit adults in the Canadian Arctic.

    Science.gov (United States)

    Hopping, B N; Erber, E; Mead, E; Sheehy, T; Roache, C; Sharma, S

    2010-10-01

    Increasing consumption of non-nutrient-dense foods (NNDF), decreasing consumption of traditional foods (TF) and low consumption of fruit and vegetables (FV) may contribute to increasing chronic disease rates amongst Inuit. The present study aimed to assess the daily frequency and socioeconomic and demographic factors influencing consumption of TF, FV and NNDF amongst Inuit adults in Nunavut, Canada. Using a cross-sectional study design and random household sampling in three communities in Nunavut, a food frequency questionnaire developed for the population was used to assess frequency of NNDF, TF and FV consumption amongst Inuit adults. Socioeconomic status (SES) was assessed by education level, ownership of items in working condition, and whether or not people in the household were employed or on income support. Mean frequencies of daily consumption were compared across gender and age groups, and associations with socioeconomic indicators were analysed using logistic regression. Two hundred and eleven participants (36 men, 175 women; mean (standard deviation) ages 42.1 (15.0) and 42.2 (13.2) years, respectively; response rate 69-93%) completed the study. Mean frequencies of consumption for NNDF, TF and FV were 6.3, 1.9 and 1.6 times per day, respectively. On average, participants ≤50 years consumed NNDF (P=0.003) and FV (P=0.01) more frequently and TF (P=0.01) less frequently than participants >50 years. Education was positively associated with FV consumption and negatively associated with TF consumption. Households on income support were more likely to consume TF and NNDF. These results support the hypothesis that the nutrition transition taking place amongst Inuit in Nunavut results in elevated consumption of NNDF compared with TF and FV. © 2010 The Authors. Journal compilation © 2010 The British Dietetic Association Ltd.

  1. Are white storks addicted to junk food? Impacts of landfill use on the movement and behaviour of resident white storks (Ciconia ciconia) from a partially migratory population.

    Science.gov (United States)

    Gilbert, Nathalie I; Correia, Ricardo A; Silva, João Paulo; Pacheco, Carlos; Catry, Inês; Atkinson, Philip W; Gill, Jenny A; Franco, Aldina M A

    2016-01-01

    The migratory patterns of animals are changing in response to global environmental change with many species forming resident populations in areas where they were once migratory. The white stork (Ciconia ciconia) was wholly migratory in Europe but recently guaranteed, year-round food from landfill sites has facilitated the establishment of resident populations in Iberia. In this study 17 resident white storks were fitted with GPS/GSM data loggers (including accelerometer) and tracked for 9.1 ± 3.7 months to quantify the extent and consistency of landfill attendance by individuals during the non-breeding and breeding seasons and to assess the influence of landfill use on daily distances travelled, percentage of GPS fixes spent foraging and non-landfill foraging ranges. Resident white storks used landfill more during non-breeding (20.1 % ± 2.3 of foraging GPS fixes) than during breeding (14.9 % ± 2.2). Landfill attendance declined with increasing distance between nest and landfill in both seasons. During non-breeding a large percentage of GPS fixes occurred on the nest throughout the day (27 % ± 3.0 of fixes) in the majority of tagged storks. This study provides first confirmation of year-round nest use by resident white storks. The percentage of GPS fixes on the nest was not influenced by the distance between nest and the landfill site. Storks travelled up to 48.2 km to visit landfills during non-breeding and a maximum of 28.1 km during breeding, notably further than previous estimates. Storks nesting close to landfill sites used landfill more and had smaller foraging ranges in non-landfill habitat indicating higher reliance on landfill. The majority of non-landfill foraging occurred around the nest and long distance trips were made specifically to visit landfill. The continuous availability of food resources on landfill has facilitated year-round nest use in white storks and is influencing their home ranges and movement behaviour. White storks rely on landfill sites for foraging especially during the non-breeding season when other food resources are scarcer and this artificial food supplementation probably facilitated the establishment of resident populations. The closure of landfills, as required by EU Landfill Directives, will likely cause dramatic impacts on white stork populations.

  2. 'We've Got Some Underground Business Selling Junk Food': Qualitative Evidence of the Unintended Effects of English School Food Policies

    OpenAIRE

    Fletcher, A.; Jamal, Farah; Fitzgerald-Yau, N.; Bonell, C

    2013-01-01

    Drawing on two qualitative studies, we report evidence of pervasive black markets in confectionery, ‘junk’ food and energy drinks in English secondary schools. Data were \\ud collected at six schools through focus groups and interviews with students (n= 149) and staff (n= 36), and direct observations. Supermarkets, new technologies and teachers’ narrow focus on attainment have enabled these ‘underground businesses’ to emerge following increased\\ud state regulation of school food and drink prov...

  3. "We never ate like that, not fast food, or junk foods": accounts of changing maternal diet in a tourist community in rural Costa Rica.

    Science.gov (United States)

    Cantor, Allison; Peña, Jenny; Himmelgreen, David

    2013-01-01

    This investigation examines maternal diet in rural Costa Rica in the context of recent political economic changes. Results show that increased availability of non-local food items, (i.e., pizza and processed foods) has influenced maternal dietary choices. Information pathways, which have traditionally provided women with knowledge about maternal diet from family members, are also shifting. Younger women turn to the local clinic and the media for information about maternal diet, and traditional practices, such as cuarentena (40-day postpartum period), are no longer being observed. Changing practices may be linked with shifting information pathways, as well as self-reported weight gain among women.

  4. A wideband sensitive holographic photopolymer

    Institute of Scientific and Technical Information of China (English)

    Mingju Huang; Sulian Wang; Airong Wang; Qiaoxia Gong; Fuxi Gan

    2005-01-01

    A novel wideband sensitive dry holographic photopolymer sensitized by rose bengal (RB) and methylene blue (MB) is fabricated, the holographic storage characteristics of which are investigated under different exposure wavelengths. The result shows that the sensitive spectral band exceeds 200 nm in visible light range, the maximum diffraction efficiency under different exposure wavelengths is more than 40% and decreases with the decrease of exposure wavelength, the exposure sensitivity is not change with the exposure wavelength.This photopolymer is appropriate for wavelength multiplexing or multi-wavelength recording in digital holographic storage.

  5. Application of Mellin Transform in Wideband Underwater Acoustic Signal Processing

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    According to the features of the wideband underwater acoustic signals, an algorithm for the wideband ambiguity function is put forward based on Mellin transform. The wideband acoustic signal processing using the fast Mellin transform is also explored. The theoretical analysis and simulation results show that the algorithm has not only high computation efficiency but also good concentration in wideband ambiguity domain. It suits for the wideband underwater acoustic signal processing.

  6. Introduction to Ultra Wideband for Wireless Communications

    DEFF Research Database (Denmark)

    Nikookar, Homayoun; Prasad, Ramjee

    wireless channels, interference, signal processing as well as applications and standardization activities are addressed. Introduction to Ultra Wideband for Wireless Communications provides easy-to-understand material to (graduate) students and researchers working in the field of commercial UWB wireless......Ultra Wideband (UWB) Technology is the cutting edge technology for wireless communications with a wide range of applications. In Introduction to Ultra Wideband for Wireless Communications UWB principles and technologies for wireless communications are explained clearly. Key issues such as UWB...... communications. Due to tutorial nature of the book it can also be adopted as a textbook on the subject in the Telecommunications Engineering curriculum. Problems at the end of each chapter extend the reader's understanding of the subject. Introduction to Ultra Wideband for Wireless Communications will aslo...

  7. Hemispheric ultra-wideband antenna.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert Wesley

    2006-04-01

    This report begins with a review of reduced size ultra-wideband (UWB) antennas and the peculiar problems that arise when building a UWB antenna. It then gives a description of a new type of UWB antenna that resolves these problems. This antenna, dubbed the hemispheric conical antenna, is similar to a conventional conical antenna in that it uses the same inverted conical conductor over a ground plane, but it also uses a hemispheric dielectric fill in between the conductive cone and the ground plane. The dielectric material creates a fundamentally new antenna which is reduced in size and much more rugged than a standard UWB conical antenna. The creation of finite-difference time domain (FDTD) software tools in spherical coordinates, as described in SAND2004-6577, enabled this technological advance.

  8. Wideband Antennas for Modern Radar Systems

    OpenAIRE

    Ren, Yu-Jiun; Lai, Chieh-Ping

    2010-01-01

    In this chapter, the basics of the antenna and phased array are reviewed and different wideband antennas for modern radar systems are presented. The concepts of the radome and frequency selective surface are also reviewed. The main contents include important parameters of the antenna, and theory and design consideration of the array antenna. Various wideband antennas are introduced and their performances are demonstrated, including: (1) for the phased array radar, the slotted waveguide array ...

  9. Ultra wideband antennas design, methodologies, and performance

    CERN Document Server

    Galvan-Tejada, Giselle M; Jardón Aguilar, Hildeberto

    2015-01-01

    Ultra Wideband Antennas: Design, Methodologies, and Performance presents the current state of the art of ultra wideband (UWB) antennas, from theory specific for these radiators to guidelines for the design of omnidirectional and directional UWB antennas. Offering a comprehensive overview of the latest UWB antenna research and development, this book:Discusses the developed theory for UWB antennas in frequency and time domainsDelivers a brief exposition of numerical methods for electromagnetics oriented to antennasDescribes solid-planar equivalen

  10. Wideband Analog Data System (WADS), system design document

    Science.gov (United States)

    Brose, J. F.

    1979-01-01

    The Wideband Analog System (WADS) which performs post flight structural dynamic analysis of wideband FM data recorded during orbital flight tests is defined. Screening, reporting, and plotting steady state and transient wave analysis data are provided by WADS.

  11. Wideband Lithium Niobate FBAR Filters

    Directory of Open Access Journals (Sweden)

    Thomas Baron

    2013-01-01

    Full Text Available Filters based on film bulk acoustic resonators (FBARs are widely used for mobile phone applications, but they can also address wideband aerospace requirements. These devices need high electromechanical coupling coefficients to achieve large band pass filters. The piezoelectric material LiNbO3 complies with such specifications and is compatible with standard fabrication processes. In this work, simple metal—LiNbO3—metal structures have been developed to fabricate single FBAR elements directly connected to each other on a single chip. A fabrication process based on LiNbO3/silicon Au-Au bonding and LiNbO3 lapping/polishing has been developed and is proposed in this paper. Electrical measurements of these FBAR filters are proposed and commented exhibiting filters with 8% of fractional bandwidth and 3.3 dB of insertion losses. Electrical measurements show possibilities to obtain 14% of fractional bandwidth. These devices have been packaged, allowing for power handling, thermal, and ferroelectric tests, corresponding to spatial conditions.

  12. Wideband Antenna for HPM Measurements

    Directory of Open Access Journals (Sweden)

    Kurkan Ivan

    2016-01-01

    Full Text Available The measurements of microwave pulses of gigawatt power level have a lot of constraints. A receiving antenna is a starting and core point of the measurement system. Waveguide based and dipole antennas have a limited wide bands, while the use of commercially available wideband antennas is restricted by their maximum peak power acceptances. The design of the wide band antenna with the small effective area was proposed. The characteristics of prototype were obtained in numerical simulations with ANSYS HFSS software and by calibration tests in the frequency band of 1–13 GHz. It has the effective area about the 1 mm2 in X-band and square-law dependence on the wavelength in a wide band. The cross polarization rate is more than 60 dB at the centre position and not less than 30 dB within the range of ±5° in azimuth and elevation angle. The wide beam radiation pattern forces a user to discriminate reflected signals. This antenna could greatly simplify the measurement system, replacing a set of narrow band antennas that connected to several recording channels.

  13. Active Harmonic Load–Pull With Realistic Wideband Communications Signals

    NARCIS (Netherlands)

    Marchetti, M.; Pelk, M.J.; Buisman, K.; Neo, W.C.E.; Spirito, M.; De Vreede, L.C.N.

    2008-01-01

    A new wideband open-loop active harmonic load–pull measurement approach is presented. The proposed method is based on wideband data-acquisition and wideband signal-injection of the incident and device generated power waves at the frequencies of interest. The system provides full, user defined, in-ba

  14. Wideband Monopole Antenna for WLAN Applications

    Directory of Open Access Journals (Sweden)

    Muhammad Umar

    2013-03-01

    Full Text Available This paper presents a circular patch antenna for WLAN applications with wideband characteristics. It is shown that impedance of the antenna is matched over wideband by using the partial ground plane and quarter wave transformer with slotted TX-Line. Ansoft HFSS is used for simulation tool to map the numerical results for the return loss frequency behavior of antenna. Measure of bandwidth, return loss and radiation pattern are also reported with satisfactory performance. As the patch is circular in shape so substrate is kept in the same shape. The shape of the substrate is also discussed in details for specific antenna designs.

  15. The APWL Wideband Wall Current Monitor

    CERN Document Server

    Bohl, T

    2009-01-01

    A wideband wall current monitor was designed for use in LHC. The pick-up, named APWL, is of the coaxial type. Its main mechanical and electrical parameters are described and evaluated. The measured pick-up response is used to calculate the expected bunch profile obtainable with a pick-up of this type.

  16. Wideband radar micro-doppler applications

    Science.gov (United States)

    Tahmoush, Dave

    2013-05-01

    Wideband radar provides a significant improvement over traditional narrowband radars for micro-Doppler analysis because the high bandwidth can be used to separate many of the signals in range, allowing a simpler decomposition of the micro-Doppler signals. Recent wideband radar work has focused on micro-Doppler, but there is a point where the narrowband approach used to analyze the micro-Doppler signals breaks down. The effect is shown to be independent of frequency, but the error relative to the bandwidth is shown to be inversely proportional to the frequency and proportional to the velocity of the subject. This error can create a smearing effect in the observed Doppler if it is not corrected, leading to reduced signal-to-noise and the appearance of more diffuse targets in Doppler space. In range-space, wideband data can also break the subject into several range bins, affecting the observed signal to noise ratio. The possible applications of wideband micro-Doppler radar are also shown, including the separation of arm movement from human motion which implies that the arms are not encumbered.

  17. Ultra-wideband radar sensors and networks

    Science.gov (United States)

    Leach, Jr., Richard R; Nekoogar, Faranak; Haugen, Peter C

    2013-08-06

    Ultra wideband radar motion sensors strategically placed in an area of interest communicate with a wireless ad hoc network to provide remote area surveillance. Swept range impulse radar and a heart and respiration monitor combined with the motion sensor further improves discrimination.

  18. 23 CFR 751.17 - Federal participation.

    Science.gov (United States)

    2010-04-01

    ... in the costs of moving junk or scrap to a recycling place of business, or in the case of junk with little or no recycling potential, to a site for permanent disposal. In the latter case, reasonable...

  19. 美味在口 健康逃走——十大垃圾食品你还在吃吗?

    Institute of Scientific and Technical Information of China (English)

    舒开智

    2007-01-01

    <正>Do you enjoy eating hamburgers,hot dogs,French fries or chips?Are you fond of soft drinks,candy or ice cream?If your an- swers are"Yes",you’d better take care.Most of them are junk food! What is junk food? Junk food has lots of fat(脂肪),salt and sugar,but few nutrients(营养物质).Most sci- entists say junk food is unhealthy.

  20. A joint approach for reducing eccentricity and spurious gravitational radiation in binary black hole initial data construction

    OpenAIRE

    Zhang, Fan; Szilágyi, Béla

    2013-01-01

    At the beginning of binary black hole simulations, there is a pulse of spurious radiation (or junk radiation) resulting from the initial data not matching astrophysical quasi-equilibrium inspiral exactly. One traditionally waits for the junk radiation to exit the computational domain before taking physical readings, at the expense of throwing away a segment of the evolution, and with the hope that junk radiation exits cleanly. We argue that this hope does not necessarily pan out as junk radia...

  1. Wideband high frequency (HF) skywave channel parameters from narrowband measurements

    Science.gov (United States)

    Hausman, Cynthia L.; Uffelman, Donald R.; Walton, Thomas L.

    The HF wideband channel allow the use of spread-spectrum techniques to provide covert communications with low probability of intercept (LPI) and antijam protection. The objective of this work is to determine the extent to which oblique narrowband channel measurements can be used to infer effects in the wideband skywave channel. If oblique narrowband channel measurements can be used as a basis for developing wideband channel models, a large number of existing narrowband measurements can be made available for this task.

  2. Wideband P-Shaped Dielectric Resonator Antenna

    Directory of Open Access Journals (Sweden)

    M.Khalily

    2013-04-01

    Full Text Available A novel P-shaped dielectric resonator antenna (DRA is presented and investigated for wideband wireless application. By using P-shaped resonator, a wideband impedance bandwidth of 80% from 3.5 to 8.2 GHz is achieved. The antenna covers all of wireless systems like C-band, 5.2, 5.5 and 5.8 GHz-WLAN and WiMax. The proposed antenna has a low profile and the thickness of the resonator is only 5.12 mm, which is 0.06-0.14 free space wavelength. A parametric study is presented. The proposed DRA is built and the characteristics of the antenna are measured. Very good agreement between numerical and measured results is obtained.

  3. Ultra-Wideband Radio Frequency Identification Systems

    CERN Document Server

    Nekoogar, Faranak

    2012-01-01

    Ultra-Wideband Radio Frequency Identification Systems describes the essentials of radio frequency identification systems as well as their target markets. The authors provide a study of commercially available RFID systems and characterizes their performance in terms of read range and reliability in the presence of conductive and dielectric materials. The capabilities and limitations of some commercial RFID systems are reported followed by comprehensive discussions of the advantages and challenges of using ultra-wideband technology for tag/reader communications. The book presents practical aspects of UWB RFID system such as: pulse generation, remote powering, tag and reader antenna design, as well as special applications of  UWB RFIDs in a simple and easy-to-understand language.

  4. Ultra-Wideband, Short Pulse Electromagnetics 9

    CERN Document Server

    Rachidi, Farhad; Kaelin, Armin; Sabath, Frank; UWB SP 9

    2010-01-01

    Ultra-wideband (UWB), short-pulse (SP) electromagnetics are now being used for an increasingly wide variety of applications, including collision avoidance radar, concealed object detection, and communications. Notable progress in UWB and SP technologies has been achieved by investigations of their theoretical bases and improvements in solid-state manufacturing, computers, and digitizers. UWB radar systems are also being used for mine clearing, oil pipeline inspections, archeology, geology, and electronic effects testing. Ultra-wideband Short-Pulse Electromagnetics 9 presents selected papers of deep technical content and high scientific quality from the UWB-SP9 Conference, which was held from July 21-25, 2008, in Lausanne, Switzerland. The wide-ranging coverage includes contributions on electromagnetic theory, time-domain computational techniques, modeling, antennas, pulsed-power, UWB interactions, radar systems, UWB communications, and broadband systems and components. This book serves as a state-of-the-art r...

  5. AMiBA Wideband Analog Correlator

    CERN Document Server

    Li, Chao-Te; Wilson, Warwick; Lin, Kai-Yang; Chen, Ming-Tang; Ho, P T P; Chen, Chung-Cheng; Han, Chih-Chiang; Oshiro, Peter; Martin-Cocher, Pierre; Chang, Chia-Hao; Chang, Shu-Hao; Altamirano, Pablo; Jiang, Homin; Chiueh, Tzi-Dar; Lien, Chun-Hsien; Wang, Huei; Wei, Ray-Ming; Yang, Chia-Hsiang; Peterson, Jeffrey B; Chang, Su-Wei; Huang, Yau-De; Hwang, Yuh-Jing; Kesteven, Michael; Koch, Patrick; Liu, Guo-Chin; Nishioka, Hiroaki; Umetsu, Keiichi; Wei, Tashun; Wu, Jiun-Huei Proty

    2010-01-01

    A wideband analog correlator has been constructed for the Yuan-Tseh Lee Array for Microwave Background Anisotropy. Lag correlators using analog multipliers provide large bandwidth and moderate frequency resolution. Broadband IF distribution, backend signal processing and control are described. Operating conditions for optimum sensitivity and linearity are discussed. From observations, a large effective bandwidth of around 10 GHz has been shown to provide sufficient sensitivity for detecting cosmic microwave background variations.

  6. Wideband FM Demodulation and Multirate Frequency Transformations

    Science.gov (United States)

    2016-12-15

    the center frequency and bandwidth are manually assigned to each formant, which may incur serious distortion to the isolated resonance signal and... problem can be solved via populating the whole time- frequency space to take advantage of the dyadic filter bank behavior of the EMD. Currently, we only...AFRL-RV-PS- AFRL-RV-PS- TR-2016-0123 TR-2016-0123 WIDEBAND FM DEMODULATION AND MULTIRATE FREQUENCY TRANSFORMATIONS Balu Santhanam and Wenjing Liu

  7. From Fibrevision To The Multi-Star Wideband Network

    Science.gov (United States)

    Wood, R.; Moore, D.

    1984-03-01

    Following experience gained with the Fibrevision cable TV trial at Milton Keynes the implementation of a large scale multi-star wideband local network is being investigated by British Telecom. An update on the Fibrevision trial is given followed by an outline description of a future multi-star wideband network.

  8. Compact wideband CMOS receiver frontends for wireless communication

    NARCIS (Netherlands)

    Blaakmeer, Stephan Carel

    2010-01-01

    There is an increasing demand for wideband receiver frontends. This is due to the emerge of wideband wireless standards (UWB) and due to the desire for flexible radios (SDR), which can comply with multiple existing and future communication standards. Existing receiver topologies are generally narro

  9. Human Target Tracking in Multistatic Ultra-Wideband Radar

    NARCIS (Netherlands)

    He, Y.

    2014-01-01

    Multistatic ultra-wideband radar is acknowledged to be useful for human tracking in indoor surveillance. In this thesis, a global signal processing chain for detection and localization of moving human targets using a multistatic ultra-wideband radar system is proposed. The design options for the sys

  10. Noise Cancelling in Wideband CMOS LNAs

    NARCIS (Netherlands)

    Bruccoleri, F.; Klumperink, E.A.M.; Nauta, B.

    2002-01-01

    A noise-cancelling technique in a wideband LNA achieves low noise figure (NF) and source impedance matching without global feedback. The 0.25 μm LNA provides <2.4 dB NF from 0.01-2 GHz, total voltage gain is 13.7 dB, -3 dB bandwidth is 0.01-1.6 GHz, S12 is <-36 dB, and S11 is <-10 dB. IIP2 is 12 dBm

  11. Efficient structures for wideband digital receiver

    Institute of Scientific and Technical Information of China (English)

    Wang Hong; Lu Youxin; Wang Xuegang; Wan Yonglun

    2006-01-01

    Digital receivers have become more and more popular in radar, communication, and electric warfare for the advantages compared with their analog counterparts. But conventional digital receivers have been generally considered impractical for bandwidth greater than several hundreds MHz. To extend receiver bandwidth, decrease data rate and save hardware resources, three novel structures are proposed. They decimate the data stream prior to mixing and filtering, then process the multiple decimated streams in parallel at a lower rate. Consequently it is feasible to realize wideband receivers on the current ASIC devices. A design example and corresponding simulation results are demonstrated to evaluate the proposed structures.

  12. Special design topics in digital wideband receivers

    CERN Document Server

    Tsui, James B Y

    2009-01-01

    Offering engineers a thorough examination of special, more advanced aspects of digital wideband receiver design, this practical book builds on fundamental resources on the topic, helping you gain a more comprehensive understanding of the subject. This in-depth volume presents a detailed look at a complete receiver design, including the encoder. Moreover, it discusses the detection of exotic signals and provides authoritative guidance on designing receivers used in electronic warfare. From frequency modulation and biphase shifting keys, to parameter encoders in electronic warfare receivers and

  13. Real-time wideband holographic surveillance system

    Energy Technology Data Exchange (ETDEWEB)

    Sheen, David M. (1917 Hood, Richland, WA 99352); Collins, H. Dale (1751 Duluth, Richland, WA 99352); Hall, Thomas E. (8301 W. Entiat Pl., Kennewick, WA 99336); McMakin, Douglas L. (2173 Shasta Ave., Richland, WA 99352); Gribble, R. Parks (1215 Cottonwood Dr., Richland, WA 99352); Severtsen, Ronald H. (1803 Birch Ave., Richland, WA 99352); Prince, James M. (3029 W. 2nd Ave., Apt. F95, Kennewick, WA 99336); Reid, Larry D. (Rt. 1, Box 1291B, Benton City, WA 99320)

    1996-01-01

    A wideband holographic surveillance system including a transceiver for generating a plurality of electromagnetic waves; antenna for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; the transceiver also receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; a computer for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and a display for displaying the processed information to determine nature of the target. The computer has instructions to apply a three dimensional backward wave algorithm.

  14. Wideband Speech Recovery Using Psychoacoustic Criteria

    Directory of Open Access Journals (Sweden)

    Visar Berisha

    2007-08-01

    Full Text Available Many modern speech bandwidth extension techniques predict the high-frequency band based on features extracted from the lower band. While this method works for certain types of speech, problems arise when the correlation between the low and the high bands is not sufficient for adequate prediction. These situations require that additional high-band information is sent to the decoder. This overhead information, however, can be cleverly quantized using human auditory system models. In this paper, we propose a novel speech compression method that relies on bandwidth extension. The novelty of the technique lies in an elaborate perceptual model that determines a quantization scheme for wideband recovery and synthesis. Furthermore, a source/filter bandwidth extension algorithm based on spectral spline fitting is proposed. Results reveal that the proposed system improves the quality of narrowband speech while performing at a lower bitrate. When compared to other wideband speech coding schemes, the proposed algorithms provide comparable speech quality at a lower bitrate.

  15. Wideband Speech Recovery Using Psychoacoustic Criteria

    Directory of Open Access Journals (Sweden)

    Berisha Visar

    2007-01-01

    Full Text Available Many modern speech bandwidth extension techniques predict the high-frequency band based on features extracted from the lower band. While this method works for certain types of speech, problems arise when the correlation between the low and the high bands is not sufficient for adequate prediction. These situations require that additional high-band information is sent to the decoder. This overhead information, however, can be cleverly quantized using human auditory system models. In this paper, we propose a novel speech compression method that relies on bandwidth extension. The novelty of the technique lies in an elaborate perceptual model that determines a quantization scheme for wideband recovery and synthesis. Furthermore, a source/filter bandwidth extension algorithm based on spectral spline fitting is proposed. Results reveal that the proposed system improves the quality of narrowband speech while performing at a lower bitrate. When compared to other wideband speech coding schemes, the proposed algorithms provide comparable speech quality at a lower bitrate.

  16. Elementary Wideband Timing of Radio Pulsars

    CERN Document Server

    Pennucci, Timothy T; Ransom, Scott M

    2014-01-01

    We present an algorithm for the simultaneous measurement of a pulse time-of-arrival (TOA) and dispersion measure (DM) from folded wideband pulsar data. We extend the prescription put forth by Taylor (1992) to accommodate a general two-dimensional template ``portrait'', the alignment of which can be used to measure a pulse phase and DM. We show that there is a dedispersion reference frequency that removes the covariance between the two measured quantities, and note that the recovered pulse profile scaling amplitudes can provide useful information. We experiment with pulse modeling by using Gaussian-component scheme that allows for independent component evolution with frequency, a ``fiducial component'', and the inclusion of scattering. A demonstration on three years of wideband data on the bright millisecond pulsar J1824-2452A (M28A) from the Green Bank Telescope, and a suite of Monte Carlo analyses showcase and validate the algorithm. By using a simple model portrait of M28A we obtain DM trends comparable to ...

  17. A Novel Monopulse Angle Estimation Method for Wideband LFM Radars

    Directory of Open Access Journals (Sweden)

    Yi-Xiong Zhang

    2016-06-01

    Full Text Available Traditional monopulse angle estimations are mainly based on phase comparison and amplitude comparison methods, which are commonly adopted in narrowband radars. In modern radar systems, wideband radars are becoming more and more important, while the angle estimation for wideband signals is little studied in previous works. As noise in wideband radars has larger bandwidth than narrowband radars, the challenge lies in the accumulation of energy from the high resolution range profile (HRRP of monopulse. In wideband radars, linear frequency modulated (LFM signals are frequently utilized. In this paper, we investigate the monopulse angle estimation problem for wideband LFM signals. To accumulate the energy of the received echo signals from different scatterers of a target, we propose utilizing a cross-correlation operation, which can achieve a good performance in low signal-to-noise ratio (SNR conditions. In the proposed algorithm, the problem of angle estimation is converted to estimating the frequency of the cross-correlation function (CCF. Experimental results demonstrate the similar performance of the proposed algorithm compared with the traditional amplitude comparison method. It means that the proposed method for angle estimation can be adopted. When adopting the proposed method, future radars may only need wideband signals for both tracking and imaging, which can greatly increase the data rate and strengthen the capability of anti-jamming. More importantly, the estimated angle will not become ambiguous under an arbitrary angle, which can significantly extend the estimated angle range in wideband radars.

  18. Three Specialized Innovations for FAST Wideband Receiver

    Science.gov (United States)

    Zhang, Xia; Yu, Xinying; Duan, Ran; Hao, Jie; Li, Di

    2015-08-01

    The National Astronomical Observatories of the Chinese Academy of Sciences (NAOC) will soon finish the largest antenna in the world. Known as FAST, the Five-hundred-meter Aperture Spherical Radio Telescope will be the most sensitive single-dish radio telescope in the low frequency radio bands between 70 MHz and 3 GHz.To take advantage of its giant aperture, all relevant cutting-edge technology should be applied to FAST to ensure that it achieves the best possible overall performance. The wideband receiver that is currently under development can not only be directly applied to FAST, but also used for other Chinese radio telescopes, such as the Shanghai 65-meter telescope and the Xinjiang 110-meter telescope, to ensure that these telescopes are among the best in the world. Recently, rapid development related to this wideband receiver has been underway. In this paper, we will introduce three key aspects of the FAST wideband receiver project. First is the use of a high-performance analog-to-digital converter (ADC). With the cooperation of Hao Jie’s team from the Institute of Automation of the Chinese Academy of Sciences(CASIA), we have developed 3-Gsps,12-bit ADCs, which have not been used previously in astronomy, and we expect to realize the 3-GHz bandwidth in a single step by covering the entire bandwidth via interleaving or a complex fast Fourier transform (FFT).Second is the front-end analog signal integrated circuit board. We wish to achieve a series of amplification, attenuation, and mixing filtering operations on a single small board, thereby achieving digital control of the bandpass behavior both flexibly and highly-efficiently. This design will not only greatly reduce the required cost and power but will also make the best use of the digital-system’s flexibility. Third is optimization of the FFT: the existing FFT is not very efficient; therefore, we will optimize the FFT for large-scale operation. For this purpose, we intend to cascade two FFTs. Another

  19. Wideband Single Crystal Transducer for Bone Characterization Project

    Data.gov (United States)

    National Aeronautics and Space Administration — TRS Technologies proposes to develop a very wideband ultrasound diagnostic tool for quantification of trabecular bone properties for astronauts in long term space...

  20. Low-Power Wideband Digital Spectrometer for Planetary Science Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this project is to develop a wideband digital spectrometer to support space-born measurements of planetary atmospheric composition. The spectrometer...

  1. Properties of wideband resonant reflectors under fully conical light incidence

    Science.gov (United States)

    Ko, Yeong Hwan; Niraula, Manoj; Lee, Kyu Jin; Magnusson, Robert

    2016-03-01

    Applying numerical modeling coupled with experiments, we investigate the properties of wideband resonant reflectors under fully conical light incidence. We show that the wave vectors pertinent to resonant first-order diffraction under fully conical mounting vary less with incident angle than those associated with reflectors in classical mounting. Therefore, as the evanescent diffracted waves drive the leaky modes responsible for the resonance effects, fully-conical mounting imbues reflectors with larger angular tolerance than their classical counterparts. We quantify the angular-spectral performance of representative resonant wideband reflectors in conic and classic mounts by numerical calculations with improved spectra found for fully conic incidence. Moreover, these predictions are verified experimentally for wideband reflectors fashioned in crystalline and amorphous silicon in distinct spectral regions spanning the 1200-1600-nm and 1600-2400-nm spectral bands. These results will be useful in various applications demanding wideband reflectors that are efficient and materially sparse.

  2. Ultra wideband technology for wireless sensor networks

    Science.gov (United States)

    Wang, Yue; Xiong, Weiming

    2011-08-01

    Wireless sensor networks (WSNs) have emerged as an important method for planetary surface exploration. To investigate the optimized wireless technology for WSNs, we summarized the key requirements of WSNs and justified ultra wideband (UWB) technology by comparing with other competitive wireless technologies. We also analyzed network topologies as well as physical and MAC layer designs of IEEE 802.15.4a standard, which adopted impulse radio UWB (IR-UWB) technology. Our analysis showed that IR-UWB-based 802.15.4a standard could enable robust communication, precise ranging, and heterogeneous networking for WSNs applications. The result of our present work implies that UWB-based WSNs can be applied to future planetary surface exploration.

  3. Wideband pulse amplifiers for the NECTAr chip

    Science.gov (United States)

    Sanuy, A.; Delagnes, E.; Gascon, D.; Sieiro, X.; Bolmont, J.; Corona, P.; Feinstein, F.; Glicenstein, J.-F.; Naumann, C. L.; Nayman, P.; Ribó, M.; Tavernet, J.-P.; Toussenel, F.; Vincent, P.; Vorobiov, S.

    2012-12-01

    The NECTAr collaboration's FE option for the camera of the CTA is a 16 bits and 1-3 GS/s sampling chip based on analog memories including most of the readout functions. This works describes the input amplifiers of the NECTAr ASIC. A fully differential wideband amplifier, with voltage gain up to 20 V/V and a BW of 400 MHz. As it is impossible to design a fully differential OpAmp with an 8 GHz GBW product in a 0.35 CMOS technology, an alternative implementation based on HF linearized transconductors is explored. The output buffer is a class AB miller operational amplifier, with special non-linear current boost.

  4. Wideband pulse amplifiers for the NECTAr chip

    Energy Technology Data Exchange (ETDEWEB)

    Sanuy, A., E-mail: asanuy@ecm.ub.es [Dept. AM i Dept. ECM, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); Delagnes, E. [IRFU/DSM/CEA, CE-Saclay, Bat. 141 SEN Saclay, F-91191, Gif-sur-Yvette (France); Gascon, D. [Dept. AM i Dept. ECM, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); Sieiro, X. [Departament d' Electronica, Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); Bolmont, J.; Corona, P. [LPNHE, Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Barre 12-22, 1er etage, 4 place Jussieu, 75252 Paris (France); Feinstein, F. [LUPM, Universite Montpellier II and IN2P3/CNRS, CC072, bat. 13, place Eugene Bataillon, 34095 Montpellier (France); Glicenstein, J-F. [IRFU/DSM/CEA, CE-Saclay, Bat. 141 SEN Saclay, F-91191, Gif-sur-Yvette (France); Naumann, C.L.; Nayman, P. [LPNHE, Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Barre 12-22, 1er etage, 4 place Jussieu, 75252 Paris (France); Ribo, M. [Dept. AM i Dept. ECM, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); and others

    2012-12-11

    The NECTAr collaboration's FE option for the camera of the CTA is a 16 bits and 1-3 GS/s sampling chip based on analog memories including most of the readout functions. This works describes the input amplifiers of the NECTAr ASIC. A fully differential wideband amplifier, with voltage gain up to 20 V/V and a BW of 400 MHz. As it is impossible to design a fully differential OpAmp with an 8 GHz GBW product in a 0.35 CMOS technology, an alternative implementation based on HF linearized transconductors is explored. The output buffer is a class AB miller operational amplifier, with special non-linear current boost.

  5. Ultra-Wideband Transceivers for Cochlear Implants

    Directory of Open Access Journals (Sweden)

    Reisenzahn Alexander

    2005-01-01

    Full Text Available Ultra-wideband (UWB radio offers low power consumption, low power spectral density, high immunity against interference, and other benefits, not only for consumer electronics, but also for medical devices. A cochlear implant (CI is an electronic hearing apparatus, requiring a wireless link through human tissue. In this paper we propose an UWB link for a data rate of Mbps and a propagation distance up to 500 mm. Transmitters with step recovery diode and transistor pulse generators are proposed. Two types of antennas and their filter characteristics in the UWB spectrum will be discussed. An ultra-low-power back tunnel diode receiver prototype is described and compared with conventional detector receivers.

  6. Parametric estimation of ultra wideband radar targets

    Institute of Scientific and Technical Information of China (English)

    Fan Ping; Jing Zhanrong

    2009-01-01

    Based on the analysis of impulse response properties, a scattering model of ultra wideband (UWB) radar targets is developed to estimate the target parameters exactly. With this model, two algorithms of multiple signal classification (MUSIC), and matrix pencil (MP), are introduced to calculate the scattering center parame-ters of targets and their performances are compared. The simulation experiments show that there are no differ-ences in the estimation precision of MUSIC and MP methods when the signal-to-noise ratio (SNR) is larger than 13 dB. However, the MP method has a better performance than that of MUSIC method when the SNR is smaller than 13 dB. Besides, the time consuming of MP method is leas than that of MUSIC method. Therefore, the MP algorithm is preferred for the parametric estimation of UWB radar targets.

  7. 垃圾债券:一种有前景的商业冒险金融工具%Junk Bonds: A Financial Means With a Bright Future for Business Venturing

    Institute of Scientific and Technical Information of China (English)

    许胜江

    2003-01-01

    人们富裕程度的提高、投资者与创业者冒险欲望的增长、科技产业的发展和知识经济的风险本质,使垃圾债券成为一种富有前景的商业冒险金融工具.阐述了垃圾债券的产生背景、功能优势与缺陷、重要应用和发展前景.

  8. The Impact of Curtin University's Activity, Food and Attitudes Program on Physical Activity, Sedentary Time and Fruit, Vegetable and Junk Food Consumption among Overweight and Obese Adolescents: A Waitlist Controlled Trial

    OpenAIRE

    Straker, Leon M.; Howie, Erin K.; Smith, Kyla L.; Fenner, Ashley A; Kerr, Deborah A; Olds, Tim S.; Abbott, Rebecca A; Smith, Anne J

    2014-01-01

    BACKGROUND: To determine the effects of participation in Curtin University's Activity, Food and Attitudes Program (CAFAP), a community-based, family-centered behavioural intervention, on the physical activity, sedentary time, and healthy eating behaviours of overweight and obese adolescents. METHODS: In this waitlist controlled clinical trial in Western Australia, adolescents (n = 69, 71% female, mean age 14.1 (SD 1.6) years) and parents completed an 8-week intervention followed by 12 months ...

  9. The health of children vs.The governments' supervision of junk food advertisements%儿童健康与各国政府对垃圾食品广告的管理

    Institute of Scientific and Technical Information of China (English)

    王晶

    2011-01-01

    近年来欧盟、美国、以及亚洲的韩国、泰国、马来西亚等国家和地区,对垃圾食品给儿童健康带来的影响表示出不同程度的关注.为控制垃圾食品造成的危害,维护儿童群体乃至整个社会的公共健康,各国政府采取了不同的应对措施.本文旨在探讨各国政府对垃圾食品广告的管理状况,并对我国政府在垃圾食品认知和管理方面存在的不足提出思考.

  10. Naloxone treatment alters gene expression in the mesolimbic reward system in 'junk food' exposed offspring in a sex-specific manner but does not affect food preferences in adulthood.

    Science.gov (United States)

    Gugusheff, J R; Ong, Z Y; Muhlhausler, B S

    2014-06-22

    We have previously reported that the opioid receptor blocker, naloxone, is less effective in reducing palatable food intake in offspring exposed to a maternal cafeteria diet during the perinatal period, implicating a desensitization of the central opioid pathway in the programming of food preferences. The present study aimed to investigate the effect of a maternal cafeteria diet and naloxone treatment on the development of the mesolimbic reward pathway and food choices in adulthood. We measured mRNA expression of key components of the reward pathway (mu-opioid receptor, proenkephalin, tyrosine hydroxylase, D1 and D2 receptors and the dopamine active transporter (DAT)) in the nucleus accumbens (NAc) and ventral tegmental area (VTA) of the offspring of control and cafeteria fed (JF) dams at weaning and after a 10-day naloxone treatment post-weaning and determined food preferences in adulthood in the remaining offspring. Naloxone treatment decreased the expression of DAT by 8.2 fold in female control offspring but increased it by 4.3 fold in female offspring of JF dams relative to the saline-injected reference groups. Proenkephalin mRNA expression was higher in the NAc of female JF offspring compared to controls, independent of naloxone treatment (Pfood preferences in adulthood in either control or JF offspring. These data indicate that prenatal exposure to a cafeteria diet alters the impact of opioid signaling blockade in the early post-weaning period on gene expression in the central reward pathway in a sex specific manner, but that these changes in gene expression do not appear to have any persistent impact on food preferences in adulthood. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. [Weak evidence concerning sedentary lifestyle and its association with cardio-metabolic illness among young people. "Junk food" and late evenings in front of the screen part of a complex connection].

    Science.gov (United States)

    Fröberg, Andreas; Raustorp, Anders

    2015-06-16

    During recent decades there has been a rapidly growing interest in youths' sedentary behaviour and its association with cardio-metabolic health. Currently there is little-to-no evidence for a cross-sectional and longitudinal association between volume and pattern (bouts and breaks) of objectively measured sedentary behavior and body weight in youth. Likewise, there is little-to-no evidence for a cross-sectional association between volume and pattern of objectively measured sedentary behavior and other markers for cardio-metabolic risk in youth. However, there is sufficient evidence for a cross-sectional and longitudinal association between screen-time and body weight and blood pressure and blood lipids. Furthermore, there is evidence for a cross-sectional association between youths' screen-time and clustered metabolic risk and insulin resistance. Overall, the level of evidence was low and, therefore, caution is required when interpreting the results.

  12. An Ultra-Wideband Millimeter-Wave Phased Array

    Science.gov (United States)

    Novak, Markus H.; Miranda, Felix A.; Volakis, John L.

    2016-01-01

    Wideband millimeter-wave arrays are of increasing importance due to their growing use in high data rate systems, including 5G communication networks. In this paper, we present a new class of ultra-wideband millimeter wave arrays that operate from nearly 20 GHz to 90 GHz. The array is based on tightly coupled dipoles. Feeding designs and fabrication challenges are presented, and a method for suppressing feed resonances is provided.

  13. Apparatus And Method For Wireless Monitoring Using Ultra-wideband Frequencies

    KAUST Repository

    Sana, Furrukh

    2015-04-23

    A system for and a method of wirelessly monitoring one or more patients can include transmitting ultra-wideband pulses toward the one or more patients, receiving ultra-wideband signals, and sampling the ultra-wideband signals. Sampling the ultra-wideband pulses can be performed with a sample rate that is less than the Nyquist rate. Impulse response can be estimated and/or recovered by exploiting sparsity of the impulse response.

  14. A Channelization-Based DOA Estimation Method for Wideband Signals.

    Science.gov (United States)

    Guo, Rui; Zhang, Yue; Lin, Qianqiang; Chen, Zengping

    2016-07-04

    In this paper, we propose a novel direction of arrival (DOA) estimation method for wideband signals with sensor arrays. The proposed method splits the wideband array output into multiple frequency sub-channels and estimates the signal parameters using a digital channelization receiver. Based on the output sub-channels, a channelization-based incoherent signal subspace method (Channelization-ISM) and a channelization-based test of orthogonality of projected subspaces method (Channelization-TOPS) are proposed. Channelization-ISM applies narrowband signal subspace methods on each sub-channel independently. Then the arithmetic mean or geometric mean of the estimated DOAs from each sub-channel gives the final result. Channelization-TOPS measures the orthogonality between the signal and the noise subspaces of the output sub-channels to estimate DOAs. The proposed channelization-based method isolates signals in different bandwidths reasonably and improves the output SNR. It outperforms the conventional ISM and TOPS methods on estimation accuracy and dynamic range, especially in real environments. Besides, the parallel processing architecture makes it easy to implement on hardware. A wideband digital array radar (DAR) using direct wideband radio frequency (RF) digitization is presented. Experiments carried out in a microwave anechoic chamber with the wideband DAR are presented to demonstrate the performance. The results verify the effectiveness of the proposed method.

  15. A Channelization-Based DOA Estimation Method for Wideband Signals

    Directory of Open Access Journals (Sweden)

    Rui Guo

    2016-07-01

    Full Text Available In this paper, we propose a novel direction of arrival (DOA estimation method for wideband signals with sensor arrays. The proposed method splits the wideband array output into multiple frequency sub-channels and estimates the signal parameters using a digital channelization receiver. Based on the output sub-channels, a channelization-based incoherent signal subspace method (Channelization-ISM and a channelization-based test of orthogonality of projected subspaces method (Channelization-TOPS are proposed. Channelization-ISM applies narrowband signal subspace methods on each sub-channel independently. Then the arithmetic mean or geometric mean of the estimated DOAs from each sub-channel gives the final result. Channelization-TOPS measures the orthogonality between the signal and the noise subspaces of the output sub-channels to estimate DOAs. The proposed channelization-based method isolates signals in different bandwidths reasonably and improves the output SNR. It outperforms the conventional ISM and TOPS methods on estimation accuracy and dynamic range, especially in real environments. Besides, the parallel processing architecture makes it easy to implement on hardware. A wideband digital array radar (DAR using direct wideband radio frequency (RF digitization is presented. Experiments carried out in a microwave anechoic chamber with the wideband DAR are presented to demonstrate the performance. The results verify the effectiveness of the proposed method.

  16. Ultra wideband wireless body area networks

    CERN Document Server

    Thotahewa, Kasun Maduranga Silva; Yuce, Mehmet Rasit

    2014-01-01

    This book explores the design of ultra wideband (UWB) technology for wireless body-area networks (WBAN).  The authors describe a novel implementation of WBAN sensor nodes that use UWB for data transmission and narrow band for data reception, enabling low power sensor nodes, with high data rate capability.  The discussion also includes power efficient, medium access control (MAC) protocol design for UWB based WBAN applications and the authors present a MAC protocol in which a guaranteed delivery mechanism is utilized to transfer data with high priority.  Readers will also benefit from this book’s feasibility analysis of the UWB technology for human implant applications through the study of electromagnetic and thermal power absorption of human tissue that is exposed to UWB signals.   • Describes hardware platform development for IR-UWB based WBAN communication; • Discusses power efficient medium access control (MAC) protocol design for IR-UWB based WBAN applications; • Includes feasibility analy...

  17. Quadrature frequency generation for wideband wireless applications

    CERN Document Server

    Elbadry, Mohammad

    2015-01-01

    This book describes design techniques for wideband quadrature LO generation for software defined radio transceivers, with frequencies spanning 4GHz to around 80GHz. The authors discuss several techniques that can be used to reduce the cost and/or power consumption of one of the key components of the RF front-end, the quadrature local oscillator.  The discussion includes simple and useful insights into quadrature VCOs, along with numerous examples of practical techniques. ·         Provides a thorough survey of  quadrature LO generation; ·         Offers an intuitive explanation of the different quadrature VCO architectures, and categorization of these architectures based on the intuitive explanations; ·         Describes a new technique for simultaneous quadrature LO generation for channelized receivers; ·         Includes simple and detailed explanation of two new quadrature VCO techniques that improve phase-noise performance of QVCOs, while providing a large tuning rang...

  18. Some Notes on Wideband Feedback Amplifiers

    Science.gov (United States)

    Fitch, V.

    1949-03-16

    The extension of the passband of wideband amplifiers is a highly important problem to the designer of electronic circuits. Throughout the electronics industry and in many research programs in physics and allied fields where extensive use is made of video amplifiers, the foremost requirement is a passband of maximum width. This is necessary if it is desired to achieve a more faithful reproduction of transient wave forms, a better time resolution in physical measurements, or perhaps just a wider band gain-frequency response to sine wave signals. The art of electronics is continually faced with this omnipresent amplifier problem. In particular, the instrumentation techniques of nuclear physics require amplifiers with short rise times, a high degree of gain stability, and a linear response to high signal levels. While the distributed amplifier may solve the problems of those seeking only a wide passband, the requirements of stability and linearity necessitate using feedback circuits. This paper considers feedback amplifiers from the standpoint of high-frequency performance. The circuit conditions for optimum steady-state (sinusoidal) and transient response are derived and practical circuits (both interstage and output) are presented which fulfill these conditions. In general, the results obtained may be applied to the low-frequency end.

  19. A Resistive Wideband Space Beam Splitter

    CERN Document Server

    Mahesh, Nivedita; Shankar, N Udaya; Raghunathan, Agaram

    2014-01-01

    We present the design, construction and measurements of the electromagnetic performance of a wideband space beam splitter. The beam splitter is designed to power divide the incident radiation into reflected and transmitted components for interferometer measurement of spectral features in the mean cosmic radio background. Analysis of a 2-element interferometer configuration with a vertical beam splitter between a pair of antennas leads to the requirement that the beam splitter be a resistive sheet with sheet resistance {\\eta}o /2, where {\\eta}o is the impedance of free space. The transmission and reflection properties of such a sheet is computed for normal and oblique incidences and for orthogonal polarizations of the incident electric field. We have constructed such an electromagnetic beam splitter as a square soldered grid of resistors of value 180 Ohms (approximately {\\eta}o /2) and a grid size of 0.1 m, and present measurements of the reflection and transmission coefficients over a wide frequency range bet...

  20. Wideband Interferometric Sensing and Imaging Polarimetry

    Science.gov (United States)

    Verdi, James Salvatore; Kessler, Otto; Boerner, Wolfgang-Martin

    1996-01-01

    Wideband Interferometric Sensing and Imaging Polarimetry (WISIP) has become an important, indispensible tool in wide area military surveillance and global environmental monitoring of the terrestrial and planetary covers. It enables dynamic, real time optimal feature extraction of significant characteristics of desirable targets and/or target sections with simultaneous suppression of undesirable background clutter and propagation path speckle at hitherto unknown clarity and never before achieved quality. WISIP may be adopted to the detection, recognition, and identification (DRI) of any stationary, moving or vibrating targets or distributed scatterer segments versus arbitrary stationary, dynamical changing and/or moving geo-physical/ecological environments, provided the instantaneous 2x2 phasor and 4x4 power density matrices for forward propagation/backward scattering, respectively, can be measured with sufficient accuracy. For example, the DRI of stealthy, dynamically moving inhomogeneous volumetric scatter environments such as precipitation scatter, the ocean/sea/lake surface boundary layers, the littoral coastal surf zones, pack ice and snow or vegetative canopies, dry sands and soils, etc. can now be successfully realized. A comprehensive overview is presented on how these modern high resolution/precision, complete polarimetric co-registered signature sensing and imaging techniques, complemented by full integration of novel navigational electronic tools, such as DGPS, will advance electromagnetic vector wave sensing and imaging towards the limits of physical realization. Various examples utilizing the most recent image data take sets of airborne, space shuttle, and satellite imaging systems demonstrate the utility of WISIP.

  1. An Ultra-Wideband Schottky Diode Based Envelope Detector for 2.5 Gbps signals

    DEFF Research Database (Denmark)

    Cimoli, Bruno; Valdecasa, Guillermo Silva; Granja, Angel Blanco

    2016-01-01

    In this paper an ultra-wideband (UWB) Schottky diode based envelope detector is reported. The detector consists of an input matching network, a Schottky diode and wideband output filtering network. The output network is tailored to demodulate ultra-wideband amplitude shift keying (ASK) signals up...

  2. Wideband FM demodulation by injection-locked division of frequency deviation

    NARCIS (Netherlands)

    Visweswaran, A.; Long, J.R.; Staszewski, R.B.

    2014-01-01

    A novel and useful wideband FM demodulator operating across an 8 GHz IF bandwidth for application in low-power, wideband heterodyne receivers. The demodulator includes an n-stage ring oscillator that is injection locked to a wideband input signal. Locking to the input frequency, it divides the FM de

  3. An Analog Correlator for Ultra-Wideband Receivers

    Directory of Open Access Journals (Sweden)

    Tu Chunjiang

    2005-01-01

    Full Text Available We present a new analog circuit exhibiting high bandwidth and low distortion, specially designed for signal correlation in an ultra-wideband receiver front end. The ultra-wideband short impulse signals are correlated with a local pulse template by the correlator. A comparator then samples the output for signal detection. A typical Gilbert mixer core is adopted for multiplication of broadband signals up to . As a result of synchronization of the received signal and the local template, the output voltage level after integration and sampling can reach up to , which is sufficient for detection by the comparator. The circuit dissipates about from double voltage supplies of and using SiGe BiCMOS technology. Simulation results are presented to show the feasibility of this circuit design for use in ultra-wideband receivers.

  4. A new figure of merit for wideband vibration energy harvesters

    Science.gov (United States)

    Liu, W. Q.; Badel, A.; Formosa, F.; Wu, Y. P.

    2015-12-01

    The performance evaluation method is a very important part in the field of vibration energy harvesting. It provides the ability to compare and rate different vibration energy harvesters (VEHs). Considering the lack of a well-recognized tool, this article proposed a new systematic figure of merit for the appraisement of wideband VEHs. Extensive investigations are first performed for some classic figures for linear VEHs. With the common fundamental information obtained, the proposed figure integrates four essential factors: the revised energy harvester effectiveness, the mechanical quality factor, the normalized bandwidth and the effective mass density. Special considerations are devoted to the properties of wideband VEHs about the operation range and the average power in this domain which are related to the performance target of stable power output. Afterward, this new figure is applied to some literature VEHs and demonstrated to present good evaluations of wideband VEHs. Moreover, it exhibits the ability to point out the improvement information of the concerned VEHs further developments.

  5. Bit-interleaved coded modulation in the wideband regime

    CERN Document Server

    Martinez, Alfonso; Caire, Giuseppe; Willems, Frans

    2007-01-01

    The wideband regime of bit-interleaved coded modulation (BICM) in Gaussian channels is studied. The Taylor expansion of the coded modulation capacity for generic signal constellations at low signal-to-noise ratio (SNR) is derived and used to determine the corresponding expansion for the BICM capacity. Simple formulas for the minimum energy per bit and the wideband slope are given. BICM is found to be suboptimal in the sense that its minimum energy per bit can be larger than the corresponding value for coded modulation schemes. The minimum energy per bit using standard Gray mapping on M-PAM or M^2-QAM is given by a simple formula and shown to approach -0.34 dB as M increases. Using the low SNR expansion, a general trade-off between power and bandwidth in the wideband regime is used to show how a power loss can be traded off against a bandwidth gain.

  6. Properties of wideband resonant reflectors under fully conical light incidence

    CERN Document Server

    Ko, Yeong Hwan; Lee, Kyu Jin; Magnusson, Robert

    2016-01-01

    Applying numerical modeling coupled with experiments, we investigate the properties of wideband resonant reflectors under fully conical light incidence. We show that the wave vectors pertinent to resonant first-order diffraction under fully conical mounting vary less with incident angle than those associated with reflectors in classical mounting. Therefore, as the evanescent diffracted waves drive the leaky modes responsible for the resonance effects, fully-conical mounting imbues reflectors with larger angular tolerance than their classical counterparts. We quantify the angular-spectral performance of representative resonant wideband reflectors in conic and classic mounts by numerical calculations with improved spectra found for fully conic incidence. Moreover, these predictions are verified experimentally for wideband reflectors fashioned in crystalline and amorphous silicon in distinct spectral regions spanning the 1200-1600-nm and 1600-2400-nm spectral bands. These results will be useful in various applic...

  7. Compressed wideband spectrum sensing based on discrete cosine transform.

    Science.gov (United States)

    Wang, Yulin; Zhang, Gengxin

    2014-01-01

    Discrete cosine transform (DCT) is a special type of transform which is widely used for compression of speech and image. However, its use for spectrum sensing has not yet received widespread attention. This paper aims to alleviate the sampling requirements of wideband spectrum sensing by utilizing the compressive sampling (CS) principle and exploiting the unique sparsity structure in the DCT domain. Compared with discrete Fourier transform (DFT), wideband communication signal has much sparser representation and easier implementation in DCT domain. Simulation result shows that the proposed DCT-CSS scheme outperforms the conventional DFT-CSS scheme in terms of MSE of reconstruction signal, detection probability, and computational complexity.

  8. Compressed Wideband Spectrum Sensing Based on Discrete Cosine Transform

    Directory of Open Access Journals (Sweden)

    Yulin Wang

    2014-01-01

    Full Text Available Discrete cosine transform (DCT is a special type of transform which is widely used for compression of speech and image. However, its use for spectrum sensing has not yet received widespread attention. This paper aims to alleviate the sampling requirements of wideband spectrum sensing by utilizing the compressive sampling (CS principle and exploiting the unique sparsity structure in the DCT domain. Compared with discrete Fourier transform (DFT, wideband communication signal has much sparser representation and easier implementation in DCT domain. Simulation result shows that the proposed DCT-CSS scheme outperforms the conventional DFT-CSS scheme in terms of MSE of reconstruction signal, detection probability, and computational complexity.

  9. Conical Shape Antenna with Circular Slots for Ultra Wideband Applications

    Directory of Open Access Journals (Sweden)

    Ahmed H. Al-Shaheen

    2012-01-01

    Full Text Available In this paper an ultra wideband of conical shaped with different configurations are designed and simulated.The antenna is printed on FR4 dielectric substrate of dimensions 42mm X 42 mm X 1.5 mm.conical shape using as a stub with circular slot etched on the ground plane, with microstrip CPW fed. The results shows a good bandwidth impedance below (S11< -10 dB for the ultra wideband UWB range from 3.1-10.6 GHz. Parametric study is done to optimize these antennas to be fit with UWB wireless applications.

  10. Substrate Effects in Wideband SiGe HBT Mixer Circuits

    DEFF Research Database (Denmark)

    Johansen, Tom Keinicke; Vidkjær, Jens; Krozer, Viktor

    2005-01-01

    In this paper, the influence from substrate effects on the performance of wideband SiGe HBT mixer circuits is investigated. Equivalent circuit models including substrate networks are extracted from on-wafer test structures and compared with electromagnetic simulations. Electromagnetic simulations...... are also applied to predict short distance substrate coupling effects. Simulation results using extracted equivalent circuit models and substrate coupling networks are compared with experimental results obtained on a wideband mixer circuit implemented in a 0.35 μm, 60 GHz ft SiGe HBT BiCMOS process....

  11. Narrowband and wideband characterisation of satellite mobile/PCN channel

    Science.gov (United States)

    Butt, G.; Parks, M. A. N.; Evans, B. G.

    1995-01-01

    This paper presents models characterizing satellite mobile channel. Statistical narrowband models based on the CSER high elevation angle channel measurement campaign are reported. Such models are understood to be useful for communication system simulations. It has been shown from the modelling results that for the mobile satellite links at high elevation angles line-of-sight (LOS) signal is available most of the time, even under the heavy shadowing conditions. Wideband measurement campaign which CSER is about to undertake, and subsequently the modelling approach to be adopted is also discussed. It is noted that a wideband channel model is expected to provide a useful tool in investigating CDMA applications.

  12. Effect of direction on loudness for wideband and reverberant sounds

    DEFF Research Database (Denmark)

    Sivonen, Ville Pekka; Ellermeier, Wolfgang

    2006-01-01

    presented to the listeners via individual binaural synthesis. The results confirm that loudness depends on sound incidence angle, as it does for narrow-band, anechoic sounds. The directional effects, however, were attenuated with the wideband and reverberant stimuli used in the present investigation.......The effect of incidence angle on loudness was investigated for wideband and reverberant sounds. In an adaptive procedure, five listeners matched the loudness of a sound coming from five incidence angles in the horizontal plane to that of the same sound with frontal incidence. The stimuli were...

  13. An Enhancing Approach to Speech Degradation by Wideband Noise

    Institute of Scientific and Technical Information of China (English)

    LOUHongwei; HUGuangrui

    2003-01-01

    A novel speech enhancement algorithm based on the simplified Karhunen-Loeve transform is proposed to suppress the wideband noise. There are no requirements of the matrix inversion, noise whitening and SNR pre-calculating. Experiments and comparison between different speech enhancement systems by means of the distortion measure show that the proposed method performs better shaping and suppressing of the wideband noise for speech enhancement. Spectral distortions fall widely to the lower level of 5dB in different SNRs. The noisy speech is enhanced with no musical residual noise.

  14. Optimal Designs of Ultra Wide-band Communication Antennas

    Institute of Scientific and Technical Information of China (English)

    JIYicai; LIUQizhong; HEXiulian; ZHANGHou

    2004-01-01

    A novel design approach combining the Hybrid genetic algorithm (HGA) with Method of moment (MoM) is investigated for the fast optimal design of ultra wide-band loaded wire antennas. A simple filtrating procedure is used to reduce the number of the loads and the components of the loading circuits, thus making the manufacture and experimental adjustment of the antennas easier, and the reliability of the antennas enhanced. The effectivity of the proposed procedure is demonstrated through its application to the optimal design of an ultra wide-band antenna.

  15. Timed arrays wideband and time varying antenna arrays

    CERN Document Server

    Haupt, Randy L

    2015-01-01

    Introduces timed arrays and design approaches to meet the new high performance standards The author concentrates on any aspect of an antenna array that must be viewed from a time perspective. The first chapters briefly introduce antenna arrays and explain the difference between phased and timed arrays. Since timed arrays are designed for realistic time-varying signals and scenarios, the book also reviews wideband signals, baseband and passband RF signals, polarization and signal bandwidth. Other topics covered include time domain, mutual coupling, wideband elements, and dispersion. The auth

  16. Optical networks for wideband sensor array

    Science.gov (United States)

    Sheng, Lin Horng

    2011-12-01

    This thesis presents the realization of novel systems for optical sensing networks with an array of long-period grating (LPG) sensors. As a launching point of the thesis, the motivation to implement optical sensing network in precisely catering LPG sensors is presented. It highlights the flexibility of the sensing network to act as the foundation in order to boost the application of the various LPG sensor design in biological and chemical sensing. After the thorough study on the various optical sensing networks, sub-carrier multiplexing (SCM) and optical time division multiplexing (OTDM) schemes are adopted in conjunction with tunable laser source (TLS) to facilitate simultaneous interrogation of the LPG sensors array. In fact, these systems are distinct to have the capability to accommodate wideband optical sensors. Specifically, the LPG sensors which is in 20nm bandwidth are identified to operate in these systems. The working principles of the systems are comprehensively elucidated in this thesis. It highlights the mathematical approach to quantify the experimental setup of the optical sensing network. Additionally, the system components of the designs are identified and methodically characterized so that the components well operate in the designed environment. A mockup has been setup to demonstrate the application in sensing of various liquid indices and analyse the response of the LPG sensors in order to evaluate the performance of the systems. Eventually, the resemblance of the demultiplexed spectral response to the pristine spectral response are quantified to have excellent agreement. Finally, the promising result consistency of the systems is verified through repeatability test.

  17. Ultra-wideband MMICs for remote sensing applications

    DEFF Research Database (Denmark)

    Johansen, Tom Keinicke; Vidkjær, Jens; Krozer, Viktor

    2003-01-01

    This paper presents an overview of the current activity at the Technical University of Denmark in the field of ultra-wideband monolitic microwave integrated circuits (MMICs) for next-generation high-resolution synthetic aperature radar (SAR) systems. The transfer function requirements for MMIC co...

  18. Wideband scalable probe for Spherical Near-Field Antenna measurements

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Pivnenko, Sergey; Breinbjerg, Olav

    2011-01-01

    The paper presents a design of an open-boundary quad-ridged horn to be used as a wideband scalable dual-linearly polarized probe for spherical near-field antenna measurements. With a new higher-order probe correction technique developed at the Technical University of Denmark, the probe will enabl...

  19. Target Doppler Estimation Using Wideband Frequency Modulated Signals

    NARCIS (Netherlands)

    Doisy, Y.; Deruaz, L.; Beerens, S.P.; Been, R.

    2000-01-01

    The topic of this paper is the design and performance analysis of wideband sonar waveforms capable of estimating both target range and Döppler using as few replicas in the processing as possible. First, it is shown that for conventional Döppler sensitive waveforms, for which the Döppler and delay ar

  20. Aliasing-free wideband beamforming using sparse signal representation

    NARCIS (Netherlands)

    Tang, Z.; Blacquière, G.; Leus, G.

    2011-01-01

    Sparse signal representation (SSR) is considered to be an appealing alternative to classical beamforming for direction-of-arrival (DOA) estimation. For wideband signals, the SSR-based approach constructs steering matrices, referred to as dictionaries in this paper, corresponding to different frequen

  1. Fibre Optics In A Multi-Star Wideband Local Network

    Science.gov (United States)

    Fox, J. R.

    1983-08-01

    Early experience has been gained with the switched-star type of network in the Fibrevision cable TV trial at Milton Keynes, and British Telecom are progressing towards a full-scale multi-star wideband local network. This paper discusses both the present and future use of fibre optics in this type of network.

  2. Design and Optimization of Wideband Multilayer Printed Antenna Arrays

    OpenAIRE

    Riviere, B.; Jeuland, H.; Bolioli, S.

    2013-01-01

    The presentation will give an overview of ONERA recent research work in the field of wideband printed antenna arrays. A special focus will be given to the comprehensive analysis and design optimization of multilayered printed arrays for wide bandwidth and wide scan angle operation.

  3. Wideband MIMO Channel Capacity Analysis in Multiprobe Anechoic Chamber Setups

    DEFF Research Database (Denmark)

    Fan, Wei; Kyosti, Pekka; Nielsen, Jesper Ødum

    2016-01-01

    This paper discusses over the air (OTA) testing for multiple input multiple output (MIMO) capable terminals with emphasis on wideband MIMO channel capacity analysis in a multi-probe anechoic chamber setup. In the literature, the spatial correlation simulation accuracy at the receiver (Rx) side ha...

  4. MIMO-OFDM performance in relation to wideband channel properties

    NARCIS (Netherlands)

    Li, P.; Zhang, H.; Oostveen, J.; Fledderus, E.

    2010-01-01

    In this paper, the sensitivity of the error rate performance of MIMO-OFDM-based practical systems (WiMAX and LTE) to wide band channel properties is investigated. The behavior of the wideband channel is characterized in terms of delay spread (DS) and angular spread (AS). The impacts of DS and AS on

  5. Long slot arrays - Part 2: Ultra wideband test results

    NARCIS (Netherlands)

    Lee, J.J.; Livingston, S.; Koenig, R.; Nagata, D.; Lai, L.; Neto, A.

    2005-01-01

    A wideband long slot array was recently developed for radar and EW applications. Theoretically the new design has unlimited bandwidth if no ground plane is included but at the expense of 3 dB loss in gain because of bi-directional radiation. In practice, however, a ground plane is used which limits

  6. Ultra wideband coplanar waveguide fed spiral antenna for humanitarian demining

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne; Appel-Hansen, Jørgen

    2000-01-01

    to 1 bandwidth with a return loss better than 10 dB from 0.4 to 3.8 GHz is presented. A wideband balun covering the frequency range of the antenna was developed. The constructed spiral antenna is very useful in a stepped frequency ground penetrating radar for humanitarian demining due to the very...

  7. Origin of wide-band IP type II bursts

    Science.gov (United States)

    Pohjolainen, S.; Allawi, H.; Valtonen, E.

    2013-10-01

    Context. Different types of interplanetary (IP) type II bursts have been observed, where the more usual ones show narrow-band and patchy emissions, sometimes with harmonics, and which at intervals may disappear completely from the dynamic spectrum. The more unusual bursts are wide-band and diffuse, show no patches or breaks or harmonic emission, and often have long durations. Type II bursts are thought to be plasma emission, caused by propagating shock waves, but a synchrotron-emitting source has also been proposed as the origin for the wide-band type IIs. Aims: Our aim is to find out where the wide-band IP type II bursts originate and what is their connection to particle acceleration. Methods: We analyzed in detail 25 solar events that produced well-separated, wide-band IP type II bursts in 2001-2011. Their associations to flares, coronal mass ejections (CMEs), and solar energetic particle events (SEPs) were investigated. Results: Of the 25 bursts, 18 were estimated to have heights corresponding to the CME leading fronts, suggesting that they were created by bow shocks ahead of the CMEs. However, seven events were found in which the burst heights were significantly lower and which showed a different type of height-time evolution. Almost all the analyzed wide-band type II bursts were associated with very high-speed CMEs, originating from different parts of the solar hemisphere. In terms of SEP associations, many of the SEP events were weak, had poor connectivity due to the eastern limb source location, or were masked by previous events. Some of the events had precursors in specific energy ranges. These properties and conditions affected the intensity-time profiles and made the injection-time-based associations with the type II bursts difficult to interpret. In several cases where the SEP injection times could be determined, the radio dynamic spectra showed other features (in addition to the wide-band type II bursts) that could be signatures of shock fronts

  8. Las golosinas en la alimentación infantil: Análisis antropológico nutricional

    OpenAIRE

    Jackson,Portia; Romo M,Marcela; Castillo A,Marcela; Castillo-Durán,Carlos

    2004-01-01

    The increasing consumption of junk food and snacks in Chile in recent years and its association with marketing strategies and prevalent diseases, is reviewed. In the context of world economy, junk food is a global phenomenon. The availability of junk food and snacks at low prices and marketing has triggered an evolution of consumption of foods that require neither the structure nor the preparation of a formal meal. Many studies have suggested that the increase in snack consumption is associat...

  9. Las golosinas en la alimentación infantil: Análisis antropológico nutricional

    OpenAIRE

    Jackson,Portia; Romo M,Marcela; Castillo A,Marcela; Castillo-Durán,Carlos

    2004-01-01

    The increasing consumption of junk food and snacks in Chile in recent years and its association with marketing strategies and prevalent diseases, is reviewed. In the context of world economy, junk food is a global phenomenon. The availability of junk food and snacks at low prices and marketing has triggered an evolution of consumption of foods that require neither the structure nor the preparation of a formal meal. Many studies have suggested that the increase in snack consumption is associat...

  10. Wideband Direction of Arrival (DOA Estimation: A Comparative Study of Wideband MUSIC Method, Joint Diagonalization Structure (JDS Method and Beam-Space Genetic Algorithm (BGA

    Directory of Open Access Journals (Sweden)

    Sandeep Santosh

    2016-09-01

    Full Text Available In this paper, a comparative study of Wideband MUSIC method, Joint Diagonalization Structure (JDS method and Beam-Space Genetic Algorithm (BGA is presented with respect to resolution probability and Root mean square error (RMSE evaluated in both low and high Signal-to-Noise ratio (SNR regions. The simulation results show that BGA has higher resolution probability than the JDS method and Wideband MUSIC method in low SNR region while in the high SNR region, Wideband MUSIC has higher resolution probability followed by BGA and JDS method. RMSE is smallest for BGA as compared to JDS and Wideband MUSIC in low SNR region. In the high SNR region, Wideband MUSIC has smallest RMSE followed by BGA and JDS method.

  11. Reducing high calorie snack food in young adults: a role for social norms and health based messages

    OpenAIRE

    Robinson, Eric; Harris, Ellis; Thomas, Jason; Aveyard, Paul; Higgs, Suzanne

    2013-01-01

    BACKGROUND: Consumption of high calorie junk foods has increased recently, especially among young adults and higher intake may cause weight gain. There is a need to develop public health approaches to motivate people to reduce their intake of junk food. OBJECTIVE: To assess the effect of health and social norm messages on high calorie snack food intake (a type of junk food) as a function of usual intake of junk food. DESIGN: In a between-subjects design, 129 young adults (45 men and 84 women,...

  12. Thermal Studies on the SPS Wideband Transverse Feedback Kicker

    CERN Document Server

    Roggen, Toon; Hofle, Wolfgang; Montesinos, Eric; CERN. Geneva. ATS Department

    2016-01-01

    As part of the SPS wideband transverse feedback system in the framework of the LHC Injector Upgrade (LIU) project, a wideband kicker design is being proposed. Vertical beam instabilities due to intensity dependent effects (electron cloud instability (ECI) and transverse mode coupling instability (TMCI)) are potentially suppressed by using a feedback system driving such a kicker system. One of the options for a kicker is a one meter long slotted-coaxial kicker, providing a substantial vertical kick strength (10ˉ5 –10ˉ4 eV.s/m) over a bandwidth ranging from nearly DC to 1 GHz. The necessary kick strength requires a total power of 4 kW. This note describes thermal studies that assisted in the material choice of the feedthroughs of the slotted-coaxial kicker and guided the design choices.

  13. Optimization and Design of Wideband Antenna Based on Q Factor

    Directory of Open Access Journals (Sweden)

    Han Liu

    2015-01-01

    Full Text Available A wideband antenna is designed based on Q factor in this paper. Firstly, the volume-surface integral equations (VSIEs and self-adaptive differential evolution algorithm (DEA are introduced as the basic theories to optimize antennas. Secondly, we study the computation of Q of arbitrary shaped structures, aiming at designing an antenna with maximum bandwidth by minimizing the Q of the antenna. This method is much more efficient for only Q values at specific frequency points that are computed, which avoids optimizing bandwidth directly. Thirdly, an integrated method combining the above method with VSIEs and self-adaptive DEA is employed to optimize the wideband antenna, extending its bandwidth from 11.5~16.5 GHz to 7~20 GHz. Lastly, the optimized antenna is fabricated and measured. The measured results are consistent with the simulated results, demonstrating the feasibility and effectiveness of the proposed method.

  14. Detection of Wideband Signal Number Based on Bootstrap Resampling

    Directory of Open Access Journals (Sweden)

    Jiaqi Zhen

    2016-01-01

    Full Text Available Knowing source number correctly is the precondition for most spatial spectrum estimation methods; however, many snapshots are needed when we determine number of wideband signals. Therefore, a new method based on Bootstrap resampling is proposed in this paper. First, signals are divided into some nonoverlapping subbands; apply coherent signal methods (CSM to focus them on the single frequency. Then, fuse the eigenvalues with the corresponding eigenvectors of the focused covariance matrix. Subsequently, use Bootstrap to construct the new resampling matrix. Finally, the number of wideband signals can be calculated with obtained vector sequences according to clustering technique. The method has a high probability of success under low signal to noise ratio (SNR and small number of snapshots.

  15. Fundamental Limits of Wideband Localization - Part II: Cooperative Networks

    CERN Document Server

    Shen, Yuan; Win, Moe Z

    2010-01-01

    The availability of positional information is of great importance in many commercial, governmental, and military applications. Localization is commonly accomplished through the use of radio communication between mobile devices (agents) and fixed infrastructure (anchors). However, precise determination of agent positions is a challenging task, especially in harsh environments due to radio blockage or limited anchor deployment. In these situations, cooperation among agents can significantly improve localization accuracy and reduce localization outage probabilities. A general framework of analyzing the fundamental limits of wideband localization has been developed in Part I of the paper. Here, we build on this framework and establish the fundamental limits of wideband cooperative location-aware networks. Our analysis is based on the waveforms received at the nodes, in conjunction with Fisher information inequality. We provide a geometrical interpretation of equivalent Fisher information for cooperative networks....

  16. Analysis of Wideband Beamformers Designed with Artificial Neural Networks

    Science.gov (United States)

    1990-12-01

    TECHNICAL REPORT 0-90-1 ANALYSIS OF WIDEBAND BEAMFORMERS DESIGNED WITH ARTIFICIAL NEURAL NETWORKS by Cary Cox Instrumentation Services Division...included. A briel tutorial on beamformers and neural networks is also provided. 14. SUBJECT TERMS 15, NUMBER OF PAGES Artificial neural networks Fecdforwa:,l...Beamformers Designed with Artificial Neural Networks ". The study was conducted under the general supervision of Messrs. George P. Bonner, Chief

  17. Ultra-Wideband Signals for Target Detection in Foliage

    Science.gov (United States)

    2007-11-02

    1997], and Fourier analysis [ Papoulis , 1987]. This approach gives a simple intuitive physical explanation for the formation and propagation of...transform or Fast Fourier Transform (FFT) techniques can be applied to compute (2.14) and (2.15) [ Papoulis , 1987; Oppenheim et al., 1997] to obtain the...Assessment of Ultra-Wideband (UWB) Technology, Battelle Tactical Technology Center, July 13, 1990. A. Papoulis , The Fourier Integral and its

  18. A wideband IM3 cancellation technique for CMOS attenuators

    NARCIS (Netherlands)

    Cheng, W.; Oude Alink, M.S.; Annema, A.J.; Wienk, G.J.M.; Nauta, B.

    2012-01-01

    A highly linear P attenuator system using a wideband IM3 cancellation technique is presented that provides 4 discrete attenuation levels with 6dB spacing for DC-5GHz. For the whole band, S11<-14dB, attenuation flatness<1.6dB, +10dBm input P1dB and +26dBm IIP3 are achieved. For the TV band (0.1Gz-1.2

  19. Ultra-Wideband Coplanar-Fed Monopoles: A Comparative Study

    Directory of Open Access Journals (Sweden)

    J. Jilkova

    2008-04-01

    Full Text Available The paper provides an experimental comparison of four types of ultra-wideband coplanar-fed planar monopole antennas. Parameters of the open stub completed by an L-shaped monopole and the cross monopole were adopted from the literature. The forked monopole and the coplanar monopole were fabricated and measured. Monopoles were compared from the viewpoint of the impedance bandwidth, gain, directivity patterns and dimensions.

  20. Closely Mounted Compact Wideband Diversity Antenna for Mobile Phone Applications

    Directory of Open Access Journals (Sweden)

    Bunggil Yu

    2012-01-01

    Full Text Available Here a compact wideband diversity antenna covering the PCS/UMTS/WiMAX bands with high isolation and low enveloped correlation coefficient (ECC is proposed. To widen the bandwidth, the proposed antenna uses a structure with a gap-coupled feed and an inductively shorted line that has capacitive compensation between the radiator and the ground plane. Also, a suspended line with a parasitic element is used to enhance the isolation between the two antennas.

  1. Ruggedizing Printed Circuit Boards Using a Wideband Dynamic Absorber

    Directory of Open Access Journals (Sweden)

    V.C. Ho

    2003-01-01

    Full Text Available The existing approaches to ruggedizing inherently fragile and sensitive critical components of electronic equipment such as printed circuit boards (PCB for use in hostile industrial and military environment are either insufficient or expensive. This paper addresses a novel approach towards ruggedizing commercial-off-the-shelf PCBs using a miniature wideband dynamic absorber. The optimisation technique used relies on the experimentally measured vibration spectra and complex receptance of the original PCB.

  2. Properties of wideband resonant reflectors under fully conical light incidence

    OpenAIRE

    Ko, Yeong Hwan; Niraula, Manoj; Lee, Kyu Jin; Magnusson, Robert

    2016-01-01

    Applying numerical modeling coupled with experiments, we investigate the properties of wideband resonant reflectors under fully conical light incidence. We show that the wave vectors pertinent to resonant first-order diffraction under fully conical mounting vary less with incident angle than those associated with reflectors in classical mounting. Therefore, as the evanescent diffracted waves drive the leaky modes responsible for the resonance effects, fully-conical mounting imbues reflectors ...

  3. The Wideband Slope of Interference Channels: The Infinite Bandwidth Case

    CERN Document Server

    Shen, Minqi

    2010-01-01

    It is well known that minimum received energy per bit in the interference channel is $-1.59dB$ as if there were no interference. Thus, the best way to mitigate interference is to operate the interference channel in the low power regime, that is in the limit of infinite bandwidth. However, when the bandwidth is large, but finite, minimum received energy per bit alone does not characterize performance. Verdu introduced the wideband slope $\\mathcal{S}_{0}$ to characterize the performance in this regime. We show that a wideband slope of ${\\mathcal{S}_{0}}/{\\mathcal{S}_{0,{no interference}}}=1/2$ is achievable. This result is similar to recent results on degrees of freedom in the high SNR regime, and we use a type of interference alignment using delays to obtain the result. We also show that in many cases the wideband slope is upper bounded by ${\\mathcal{S}_{0}}/{\\mathcal{S}_{0,{no interference}}}\\leq 1/2}$ for large number of users $K$.

  4. Capacity of Sparse Wideband Channels with Partial Channel Feedback

    CERN Document Server

    Hariharan, Gautham; Sayeed, Akbar M

    2008-01-01

    This paper studies the ergodic capacity of wideband multipath channels with limited feedback. Our work builds on recent results that have established the possibility of significant capacity gains in the wideband/low-SNR regime when there is perfect channel state information (CSI) at the transmitter. Furthermore, the perfect CSI benchmark gain can be obtained with the feedback of just one bit per channel coefficient. However, the input signals used in these methods are peaky, that is, they have a large peak-to-average power ratios. Signal peakiness is related to channel coherence and many recent measurement campaigns show that, in contrast to previous assumptions, wideband channels exhibit a sparse multipath structure that naturally leads to coherence in time and frequency. In this work, we first show that even an instantaneous power constraint is sufficient to achieve the benchmark gain when perfect CSI is available at the receiver. In the more realistic non-coherent setting, we study the performance of a tra...

  5. Design of a wideband excitation source for fast bioimpedance spectroscopy

    Science.gov (United States)

    Yang, Yuxiang; Kang, Minhang; Lu, Yong; Wang, Jian; Yue, Jing; Gao, Zonghai

    2011-01-01

    Multi-frequency-one-time (MFOT) measurement of bioimpedance spectroscopy (BIS) can greatly reduce measurement time and grasp the transient physiological status of a living body compared with the traditional one-frequency-one-time (OFOT) measurement technology, and a wideband excitation source mixed with multiple frequencies is a crucial part of MFOT measurement of BIS. This communication describes a design of a wideband excitation source. Firstly, a multi-frequency mixed (MFM) signal containing seven primary harmonics is synthesized based on Walsh functions, which is a periodical and rectangular signal and whose 68.9% of the energy is homogeneously distributed on its seven 2nth primary harmonics. Then the MFM signal is generated by a field programmable gate array (FPGA), and a unipolar-to-bipolar convertor (UBC) is designed to convert the unipolar signal into bipolar signal. Finally, the bipolar MFM signal is driven by a voltage-controlled current source (VCCS). A 2R-1C series model is adopted as the load of the VCCS, and the simulated voltage response on the load is obtained based on the theoretical analysis. Experiments show that the practical waveform on the load matches well with the theoretical analysis, which indicates that the VCCS has a good performance on the MFM signal. The design of the wideband excitation source establishes a good foundation for fast measurement of BIS.

  6. Age effects in the human middle ear: Wideband acoustical measures

    Science.gov (United States)

    Feeney, M. Patrick; Sanford, Chris A.

    2004-12-01

    Studies that have examined age effects in the human middle ear using either admittance measures at 220 or 660 Hz or multifrequency tympanometry from 200 to 2000 Hz have had conflicting results. Several studies have suggested an increase in admittance with age, while several others have suggested a decrease in admittance with age. A third group of studies found no significant age effect. This study examined 226 Hz tympanometry and wideband energy reflectance and impedance at ambient pressure in a group of 40 young adults and a group of 30 adults with age >=60 years. The groups did not differ in admittance measures of the middle ear at 226 Hz. However, significant age effects were found in wideband energy reflectance and impedance. In particular, in older adults there was a comparative decrease in reflectance from 800 to 2000 Hz but an increase near 4000 Hz. The results suggest a decrease in middle-ear stiffness with age. The findings of this study hold relevance for understanding the aging process in the auditory system, for the establishment of normative data for wideband energy reflectance, for the possibility of a conductive component to presbycusis, and for the interpretation of otoacoustic emission measurements. .

  7. Wideband Spectrum Sensing at Sub-Nyquist Rates

    CERN Document Server

    Mishali, Moshe

    2010-01-01

    We present a mixed analog-digital spectrum sensing method that is especially suited to the typical wideband setting of cognitive radio (CR). The advantages of our system with respect to current architectures are threefold. First, our analog front-end is fixed and does not involve scanning hardware. Second, both the analog-to-digital conversion (ADC) and the digital signal processing (DSP) rates are substantially below Nyquist. Finally, the sensing resources are shared with the reception path of the CR, so that the lowrate streaming samples can be used for communication purposes of the device, besides the sensing functionality they provide. Combining these advantages leads to a real time map of the spectrum with minimal use of mobile resources. Our approach is based on the modulated wideband converter (MWC) system, which samples sparse wideband inputs at sub-Nyquist rates. We report on results of hardware experiments, conducted on an MWC prototype circuit, which affirm fast and accurate spectrum sensing in par...

  8. Generating all two-MOS-transistor amplifiers leads to new wide-band LNAs

    NARCIS (Netherlands)

    Bruccoleri, F.; Klumperink, Eric A.M.; Nauta, Bram

    This paper presents a methodology that systematically generates all 2-MOS-transistor wide-band amplifiers, assuming that MOSFET is exploited as a voltage-controlled current source. This leads to new circuits. Their gain and noise factor have been compared to well-known wide-band amplifiers. One of

  9. Machine Learning Aided Efficient and Robust Algorithms for Spectrum Knowledge Acquisition in Wideband Autonomous Cognitive Radios

    Science.gov (United States)

    2016-08-01

    WIDEBAND AUTONOMOUS COGNITIVE RADIOS Sudharman Jayaweera Department of Electrical and Computer Engineering University of New Mexico Albuquerque, NM...of Electrical and Computer Engineering 8. PERFORMING ORGANIZATION REPORT NUMBER University of New Mexico Albuquerque, NM 87131 9. SPONSORING...1, is the wideband spectrum scanning [1,8]. Hardware constraints limit the instantaneous sensing bandwidth of most state-of-the- art software

  10. Effects of Consecutive Wideband Tympanometry Trials on Energy Absorbance Measures of the Middle Ear

    Science.gov (United States)

    Burdiek, Laina M.; Sun, Xiao-Ming

    2014-01-01

    Purpose: Wideband acoustic immittance (WAI) is a new technique for assessing middle ear transfer function. It includes energy absorbance (EA) measures and can be acquired with the ear canal pressure varied, known as "wideband tympanometry" (WBTymp). The authors of this study aimed to investigate effects of consecutive WBTymp testing on…

  11. GaAs Wideband Low Noise Amplifier Design for Breast Cancer Detection System

    DEFF Research Database (Denmark)

    Yan, Lei; Krozer, Viktor; Delcourt, Sebastien

    2009-01-01

    Modern wideband systems require low-noise receivers with bandwidth approaching 10 GHz. This paper presents ultra-wideband stable low-noise amplifier MMIC with cascode and source follower buffer configuration using GaAs technology. Source degeneration, gate and shunt peaking inductors are used to ...

  12. Wideband Acoustic Immittance: Normative Study and Test-Retest Reliability of Tympanometric Measurements in Adults

    Science.gov (United States)

    Sun, Xiao-Ming

    2016-01-01

    Purpose: The purpose of this study was to present normative data of tympanometric measurements of wideband acoustic immittance and to characterize wideband tympanograms. Method: Data were collected in 84 young adults with strictly defined normal hearing and middle ear status. Energy absorbance (EA) was measured using clicks for 1/12-octave…

  13. Fast Computation of Wideband Beam Pattern for Designing Large-Scale 2-D Arrays.

    Science.gov (United States)

    Chi, Cheng; Li, Zhaohui

    2016-06-01

    For real-time and high-resolution 3-D ultrasound imaging, the design of sparse distribution and weights of elements of a large-scale wideband 2-D array is needed to reduce hardware cost and achieve better directivity. However, due to the high time consumption of computing the wideband beam pattern, the design methods that need massive iterations have rarely been applied to design large-scale wideband 2-D arrays by directly computing the wideband beam pattern. In this paper, a fast method is proposed to realize the computation of a wideband beam pattern of arbitrary 2-D arrays in the far field in order to design large-scale wideband 2-D arrays. The proposed fast method exploits two important techniques: 1) nonuniform fast Fourier transform (FFT) and 2) short inverse FFT. Compared with the commonly used ultrasound simulator Field II, two orders of magnitude improvement in computation speed is achieved with comparable accuracy. The proposed fast method enables massive iterations of direct wideband beam pattern computation of arbitrary large-scale 2-D arrays. A design example in this paper demonstrates that the proposed fast method can help achieve better performance in designing large-scale wideband 2-D arrays.

  14. Time-integrating acousto-optic correlator for wideband random noise radar

    Science.gov (United States)

    Kim, Sangtaek; Narayanan, Ram; Zhou, Wei; Wagner, Kelvin

    2004-10-01

    A time-integrating acousto-optic correlator (TIAOC) is a good candidate for imaging and target detection using a wideband random noise radar system. We have developed such a correlator for a random noise radar with a signal frequency range of 1-2 GHz. This system has demonstrated good wideband signal correlation performance with good dynamic range and fine tuning of delays.

  15. Wide-band heterodyne receiver development for effluent measurements

    Energy Technology Data Exchange (ETDEWEB)

    Hutchinson, D.P.; Richards, R.K.; Simpson, M.L.; Bennett, C.A. [Oak Ridge National Lab., TN (United States); Liu, H.C.; Buchanan, M. [National Research Council of Canada (Canada)

    1998-05-01

    Oak Ridge National Laboratory (ORNL) has been developing advanced infrared heterodyne receivers for plasma diagnostics in fusion reactors for over 20 years. Passive heterodyne radiometry in the LWIR region of the spectrum has historically been restricted by HgCdTe (MCT) detector technology to receiver bandwidths of only 2 GHz. Given typical atmospheric line widths of approximately 3 GHz, a CO{sub 2} (or isotope) laser local oscillator with an average line spacing of 50 GHz, and an MCT detector, only chemical species whose absorptions fall directly on top of laser lines can be measured. Thus, with traditional narrow-band heterodyne radiometry, much of the LWIR spectrum is missed and the less complex direct detection DIAL has been the preferred technique in remote sensing applications. Wide-band heterodyne receivers offer significant improvements in remote measurement capability. Progress at the Institute for Microstructural Sciences (IMS) at National Research Council of Canada and at ORNL in wide-band quantum-well infrared photodetectors (QIPs) and receivers is significantly enhancing the bandwidth capabilities of heterodyne radiometers. ORNL recently made measurements in the lab using QWIPs developed at IMS that demonstrate heterodyne quantum efficiencies of 5% with a heterodyne bandwidth of 7 GHz. The path forward indicates that > 10% heterodyne quantum efficiencies and 30-GHz bandwidths are achievable with current QWIP technology. With a chopped, 30-GHz passive heterodyne receiver, a much larger portion of the LWIR spectrum can now be covered. One potential advantage of wide-band heterodyne receivers for effluent measurements is to dramatically reduce the number of laser lines needed to characterize and distinguish multiple chemical species of interest. In the following paper, the authors discuss this and other implications of these new technologies to the characterization of effluents using both passive heterodyne radiometry and thermo-luminescence.

  16. Design and Implementation of a Cueing Wideband Digital EW Receiver

    Institute of Scientific and Technical Information of China (English)

    ZHU Jun; TANG Bin; WU Wei; JIANG Zong-ming; ZHANG Chang-ju; YIN Mao-wei; DEN Ming-yi; DU Dong-ping

    2006-01-01

    A cueing wideband digital Electronic Warfare (EW) receiver is presented. The proposed receiver, which is to measure the instantaneous frequency and bandwidth of the intercept short-duration pulse radar signals that cue and match the corresponding ones, meets the requirements of good sensitivity and dynamic range for EW and can save hardware resources greatly as well. In addition, real-time signal processing, which is the main bottleneck for covering a wide instantaneous frequency band for EW receiver, is better solved in the proposed design structure. The highly efficient implementation and good parameter estimation algorithms are proposed as well. Theoretical analysis and experimental results show that this structure is feasible.

  17. Ultra-wideband and 60 GHz communications for biomedical applications

    CERN Document Server

    Yuce, Mehmet R

    2013-01-01

    This book investigates the design of devices, systems, and circuits for medical applications using the two recently established frequency bands: ultra-wideband (3.1-10.6 GHz) and 60 GHz ISM band. These two bands provide the largest bandwidths available for communication technologies and present many attractive opportunities for medical applications. The applications of these bands in healthcare are wireless body area network (WBAN), medical imaging, biomedical sensing, wearable and implantable devices, fast medical device connectivity, video data transmission, and vital signs monitoring. The r

  18. Wideband EMI pre-screening for landmine detection

    Science.gov (United States)

    Wilson, J. N.; Ramachandran, G.; Gader, P. D.; Smock, B.; Scott, W. R.

    2009-05-01

    This paper considers the use of data from a wideband electromagnetic induction (EMI) sensor in a prescreener for a landmine detection system employing both ground-penetrating radar (GPR) and EMI sensors. The paper looks at a unique EMI prescreening strategy based on the use of prototypes derived from a training set of landmines. We show that this prescreener is robust to a wide range of induced energy levels in sensed objects. We also compare properties of the receiver operating characteristics (ROC) curve of this prescreener on a varied collection of targets to the properties of a GPR prescreener, identifying performance difference with respect to target object classes.

  19. Development of UAS Design Based on Wideband Antenna Architecture

    Directory of Open Access Journals (Sweden)

    Franklin Drummond

    2015-06-01

    Full Text Available An Unmanned Aerial System (UAS has been developed which is based on an aerodynamically functionalized planar wideband antenna. The antenna utilizes a planar circular dipole metallization scheme. The aerodynamic structure implements a planform similar to the Nutball flier, a hobbyist flight architecture. The resulting codesign achieved a large impedance bandwidth defined by a voltage standing wave ratio (VSWR less than 2 from 100 MHz to over 2 GHz and omnidirectional dipole-like radiation patterns at the lower frequency region and more directional patterns at higher frequencies.

  20. A Modulation Based Approach to Wideband-STAP (Postprint)

    Science.gov (United States)

    2007-10-01

    Library. Downloaded on October 7, 2009 at 18:28 from IEEE Xplore . Restrictions apply. 1 fm =[f(t-(M-I)T2 ),-, f(t-(M-I)T2-(N-I)T )] ( 12) In the wideband...F(co)H(e jco) Authorized licensed use limited to: AFRL Technical Library. Downloaded on October 7, 2009 at 18:28 from IEEE Xplore . Restrictions...AFRL Technical Library. Downloaded on October 7, 2009 at 18:28 from IEEE Xplore . Restrictions apply. 3 This combined signal is finally bandpass

  1. Wideband Holographic Digital Recording and Reproduction. Phase IV.

    Science.gov (United States)

    1980-02-01

    AD-AO86 265 HARRIS CORP MELBOURNE FL GOVERNMENT COMMUNICATION ST--ETC FIG 14/5 WIDEBAND HOLOGRAPHIC DIGITAL RECORDING AND REPRODUCTION. PHASE --ETC(U...requirements of the opto- mechanisms, and increase record time for a given film length. 3-59 AD-AOBA 265 HARRIS CORP MELBOURNE FL GOVERNMENT COMMUNICATION Sy...V 0 - 00 0 0 -~~~ -4I - N Z U -1 +1 en0- ~ V), 0 >4 C4, 00 C 0 C ;4 k .1 4-60 C AD-ADB6 265 HARRIS CORP MELBOURNE FL GOVERNMENT COMMUNICATION ST--ETC

  2. AN EFFICIENT IMPLEMENTATION ARCHITECTURE FOR WIDE-BAND DIGITAL DOWNCONVERSION

    Institute of Scientific and Technical Information of China (English)

    Gao Zhicheng; Xiao Xianci

    2001-01-01

    The wide-band digital receiving systems require digital downconversion(DDC) with high data rate and short tuning time in order to intercept the narrow-band signals within broad tuning bandwidth. But these requirements can not be met by the commercial DDC. In this paper an efficient implementation architecture is presented. It combines the flexibility of DFT tuning with the efficiency of the polyphase filter bank decomposition. By first decimating the data prior to filtering and mixing, this architecture gives a better solution to the mismatch between the lower hardware speed and high data rate. The computer simulations show the feasibility of this processing architecture.

  3. A 4-9 GHz 10 W wideband power amplifier

    Institute of Scientific and Technical Information of China (English)

    陈中子; 陈晓娟; 姚小江; 袁婷婷; 刘新宇; 李滨

    2009-01-01

    A 4-9 GHz wideband high power amplifier is designed and fabricated, which has demonstrated saturated output power of 10 W covering 6-8 GHz band, and above 6 W over the other band. This PA module uses a bal-ance configuration, and presents power gain of 7.3 ± 0.9 dB over the whole 4-9 GHz band and 39% power-added efficiency (PAE) at 8 GHz. Both the input and output VSWR are also excellent, which are bellow -10 dB.

  4. Wide-band slow-wave systems simulation and applications

    CERN Document Server

    Staras, Stanislovas

    2012-01-01

    The field of electromagnetics has seen considerable advances in recent years, based on the wide applications of numerical methods for investigating electromagnetic fields, microwaves, and other devices. Wide-Band Slow-Wave Systems: Simulation and Applications presents new technical solutions and research results for the analysis, synthesis, and design of slow-wave structures for modern electronic devices with super-wide pass-bands. It makes available, for the first time in English, significant research from the past 20 years that was previously published only in Russian and Lithuanian. The aut

  5. Wide-Band Multi-spectral Space for Color Representation

    Institute of Scientific and Technical Information of China (English)

    KONG Lingwang; ZHU Yuanhong; Kurt Muenger; ZHANG Xuliang

    2003-01-01

    This paper develops a wide-band multi-spectral space for color representation with Aitken PCA algorithm. This novel mathematical space using the broad-band spectra matching method aims at improving the accuracy of color representation as well as reducing costs for processing and storing multi-spectral images. The results show that the space can present our experimental original spectral spaces (i. e. Munsell color matt and DIN-6164 color chips) with high efficiency, and that the spanning space with three eigenvectors can present the original space at more than 98%CSCR, and when 5 eigenvectors are used it can cover almost the whole original spaces.

  6. Optically addressed ultra-wideband phased antenna array

    Science.gov (United States)

    Bai, Jian

    Demands for high data rate and multifunctional apertures from both civilian and military users have motivated development of ultra-wideband (UWB) electrically steered phased arrays. Meanwhile, the need for large contiguous frequency is pushing operation of radio systems into the millimeter-wave (mm-wave) range. Therefore, modern radio systems require UWB performance from VHF to mm-wave. However, traditional electronic systems suffer many challenges that make achieving these requirements difficult. Several examples includes: voltage controlled oscillators (VCO) cannot provide a tunable range of several octaves, distribution of wideband local oscillator signals undergo high loss and dispersion through RF transmission lines, and antennas have very limited bandwidth or bulky sizes. Recently, RF photonics technology has drawn considerable attention because of its advantages over traditional systems, with the capability of offering extreme power efficiency, information capacity, frequency agility, and spatial beam diversity. A hybrid RF photonic communication system utilizing optical links and an RF transducer at the antenna potentially provides ultra-wideband data transmission, i.e., over 100 GHz. A successful implementation of such an optically addressed phased array requires addressing several key challenges. Photonic generation of an RF source with over a seven-octave bandwidth has been demonstrated in the last few years. However, one challenge which still remains is how to convey phased optical signals to downconversion modules and antennas. Therefore, a feed network with phase sweeping capability and low excessive phase noise needs to be developed. Another key challenge is to develop an ultra-wideband array antenna. Modern frontends require antennas to be compact, planar, and low-profile in addition to possessing broad bandwidth, conforming to stringent space, weight, cost, and power constraints. To address these issues, I will study broadband and miniaturization

  7. UCom: Ultra-wideband Communications in Harsh Propagation Environments

    Energy Technology Data Exchange (ETDEWEB)

    Nekoogar, F

    2007-03-14

    LLNL has developed an ultra-wideband (UWB) system that provides unique, through-the-wall wireless communications in heavy metallic and heavy concrete indoor channels. LLNL's UWB system is the only available wireless communications system that performs successfully and reliably in facilities where conventional narrowband communications usually fail due to destructive reflections from multiple surfaces. These environments include: cargo ships and reinforced, heavy concrete buildings. LLNL's revolutionary system has applications for the military, as well as commercial indoor communications in multistory buildings, and cluttered industrial structures.

  8. A NOVEL WIDEBAND ANTENNA DESIGN USING U-SLOT

    Institute of Scientific and Technical Information of China (English)

    Chai Wenwen; Zhang Xiaojuan

    2008-01-01

    U-slot patch antennas with ∏-shaped feed slot are studied, and numerical results based on the FDTD method are presented. The effects of varying physical parameters are investigated with a goal of understanding the coupling among different resonators. It is found that the U-slot patch antenna can be designed to attain 50% impedance bandwidth as well as 30-40% gain bandwidth. By altering the sizes of U-slot and feed slot, the wideband characteristic can be changed into a dual-frequency characteristic.

  9. Antenna Characterization for the Wideband Instrument for Snow Measurements (WISM)

    Science.gov (United States)

    Lambert, Kevin M.; Miranda, Felix A.; Romanofsky, Robert R.; Durham, Timothy E.; Vanhille, Kenneth J.

    2015-01-01

    Experimental characterization of the antenna for the Wideband Instrument for Snow Measurement (WISM) under development for the NASA Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP), is discussed. A current sheet antenna, consisting of a small, 6x6 element, dual-linear polarized array with integrated beamformer, feeds an offset parabolic reflector, enabling WISM operation over an 8 to 40 GHz frequency band. An overview of the test program implemented for both the feed and the reflector antenna is given along with select results for specific frequencies utilized by the radar and radiometric sensors of the WISM.

  10. Antenna Characterization for the Wideband Instrument for Snow Measurements

    Science.gov (United States)

    Lambert, Kevin M.; Miranda, Felix A.; Romanofsky, Robert R.; Durham, Timothy E.; Vanhille, Kenneth J.

    2015-01-01

    Experimental characterization of the antenna for the Wideband Instrument for Snow Measurements (WISM) under development for the NASA Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP), is discussed. A current sheet antenna, consisting of a small, 6x6 element, dual-linear polarized array with integrated beamformer, feeds an offset parabolic reflector, enabling WISM operation over an 8 to 40 GHz frequency band. An overview of the test program implemented for both the feed and the reflector antenna is given along with select results for specific frequencies utilized by the radar and radiometric sensors of the WISM.

  11. NEWS: the near-infrared Echelle for wideband spectroscopy

    Science.gov (United States)

    Veyette, Mark J.; Muirhead, Philip S.; Hall, Zachary J.; Taylor, Brian; Ye, Jimmy

    2016-08-01

    We present an updated optical and mechanical design of NEWS: the Near-infrared Echelle for Wide-band Spectroscopy (formerly called HiJaK: the High-resolution J, H and K spectrometer), a compact, high-resolution, near-infrared spectrometer for 5-meter class telescopes. NEWS provides a spectral resolution of 60,000 and covers the full 0.8-2.5 μm range in 5 modes. We adopt a compact, lightweight, monolithic design and have developed NEWS to be mounted to the instrument cube at the Cassegrain focus of the new 4.3-meter Discovery Channel Telescope.

  12. NEWS: the near-infrared Echelle for wideband spectroscopy

    CERN Document Server

    Veyette, Mark; Hall, Zachary; Taylor, Brian; Ye, Jimmy

    2016-01-01

    We present an updated optical and mechanical design of NEWS: the Near-infrared Echelle for Wide-band Spectroscopy (formerly called HiJaK: the High-resolution J, H and K spectrometer), a compact, high-resolution, near-infrared spectrometer for 5-meter class telescopes. NEWS provides a spectral resolution of 60,000 and covers the full 0.8-2.5 micron range in 5 modes. We adopt a compact, lightweight, monolithic design and developed NEWS to be mounted to the instrument cube at the Cassegrain focus of the the new 4.3-meter Discovery Channel Telescope.

  13. Continuously tunable wideband semiconductor fiber-ring laser

    Science.gov (United States)

    Mao, Xuefeng; Zhao, Shiwei; Yuan, Suzhen; Wang, Xiaofa; Zheng, Peichao

    2017-08-01

    We demonstrate a wideband tunable semiconductor fiber-ring laser that can be continuously tuned from 1498 nm to 1623 nm. The proposed laser uses a semiconductor optical amplifier (SOA) as a gain medium and a fiber Fabry-Perot tunable filter as a selective wavelength filter. The optimized drive current of the SOA and the output coupling ratio are obtained by experimental research. This laser has a simple configuration, low threshold, flat laser output power and high optical signal-to-noise ratio.

  14. Ultra-wideband reflective polarization converter based on anisotropic metasurface

    Science.gov (United States)

    Wu, Jia-Liang; Lin, Bao-Qin; Da, Xin-Yu

    2016-08-01

    In this paper, we propose an ultra-wideband reflective linear cross-polarization converter based on anisotropic metasurface. Its unit cell is composed of a square-shaped resonator with intersectant diagonal and metallic ground sheet separated by dielectric substrate. Simulated results show that the converter can generate resonances at four frequencies under normal incident electromagnetic (EM) wave, leading to the bandwidth expansion of cross-polarization reflection. For verification, the designed polarization converter is fabricated and measured. The measured and simulated results agree well with each other, showing that the fabricated converter can convert x- or y-polarized incident wave into its cross polarized wave in a frequency range from 7.57 GHz to 20.46 GHz with a relative bandwidth of 91.2%, and the polarization conversion efficiency is greater than 90%. The proposed polarization converter has a simple geometry but an ultra wideband compared with the published designs, and hence possesses potential applications in novel polarization-control devices. Project supported by the National Natural Science Foundation of China (Grant Nos. 61471387, 61271250, and 61571460).

  15. Wideband-Switchable Metamaterial Absorber Using Injected Liquid Metal

    Science.gov (United States)

    Kim, Hyung Ki; Lee, Dongju; Lim, Sungjoon

    2016-01-01

    Metamaterial absorbers can provide good solutions for radar-cross-section (RCS) reduction. In spite of their attractive features of thinness, lightness, and low cost, resonant metamaterial absorbers have a drawback of narrow bandwidth. For practical radar applications, wideband absorbers are necessary. In this paper, we propose a wideband-switchable metamaterial absorber using liquid metal. In order to reduce RCS both for X-band and C-band, the switchable Jerusalem cross (JC) resonator is introduced. The JC resonator consists of slotted circular rings, chip resistors, and microfluidic channels. The JC resonator is etched on a flexible printed circuit board (FPCB), and the microfluidic channels are laser-etched on a polydimethylsiloxane (PDMS) material. The proposed absorber can switch the absorption frequency band by injecting a liquid metal alloy into the channels. The performance of the absorber was demonstrated through full-wave simulation and through measurements employing prototypes. The experimental results showed absorption ratios of over 90% from 7.43 GHz to 14.34 GHz, and from 5.62 GHz to 7.3 GHz, with empty channels and liquid metal-filled channels, respectively. Therefore, the absorption band was successfully switched between the C-band (4–8 GHz) and the X-band (8–12 GHz) by injecting liquid metal eutectic gallium indium alloy (EGaIn) into the channels. PMID:27546310

  16. Wideband digital phase comparator for high current shunts

    CERN Document Server

    Pogliano, Umberto; Serazio, Danilo

    2011-01-01

    A wideband phase comparator for precise measurements of phase difference of high current shunts has been developed at INRIM. The two-input digital phase detector is realized with a precision wideband digitizer connected through a pair of symmetric active guarded transformers to the outputs of the shunts under comparison. Data are first acquired asynchronously, and then transferred from on-board memory to host memory. Because of the large amount of data collected the filtering process and the analysis algorithms are performed outside the acquisition routine. Most of the systematic errors can be compensated by a proper inversion procedure. The system is suitable for comparing shunts in a wide range of currents, from several hundred of milliampere up to 100 A, and frequencies ranging between 500 Hz and 100 kHz. Expanded uncertainty (k=2) less than 0.05 mrad, for frequency up to 100 kHz, is obtained in the measurement of the phase difference of a group of 10 A shunts, provided by some European NMIs, using a digit...

  17. Digital Front End for Wide-Band VLBI Science Receiver

    Science.gov (United States)

    Jongeling, Andre; Sigman, Elliott; Navarro, Robert; Goodhart, Charles; Rogstad, Steve; Chandra, Kumar; Finley, Sue; Trinh, Joseph; Soriano, Melissa; White, Les; hide

    2006-01-01

    An upgrade to the very-long-baseline-interferometry (VLBI) science receiver (VSR) a radio receiver used in NASA's Deep Space Network (DSN) is currently being implemented. The current VSR samples standard DSN intermediate- frequency (IF) signals at 256 MHz and after digital down-conversion records data from up to four 16-MHz baseband channels. Currently, IF signals are limited to the 265-to-375-MHz range, and recording rates are limited to less than 80 Mbps. The new digital front end, denoted the Wideband VSR, provides improvements to enable the receiver to process wider bandwidth signals and accommodate more data channels for recording. The Wideband VSR utilizes state-of-the-art commercial analog-to-digital converter and field-programmable gate array (FPGA) integrated circuits, and fiber-optic connections in a custom architecture. It accepts IF signals from 100 to 600 MHz, sampling the signal at 1.28 GHz. The sample data are sent to a digital processing module, using a fiber-optic link for isolation. The digital processing module includes boards designed around an Advanced Telecom Computing Architecture (ATCA) industry-standard backplane. Digital signal processing implemented in FPGAs down-convert the data signals in up to 16 baseband channels with programmable bandwidths from 1 kHz to 16 MHz. Baseband samples are transmitted to a computer via multiple Ethernet connections allowing recording to disk at rates of up to 1 Gbps.

  18. SEMICONDUCTOR INTEGRATED CIRCUITS: A 6-9 GHz ultra-wideband CMOS PA for China's ultra-wideband standard

    Science.gov (United States)

    Zhendong, Gao; Zhiqiang, Li; Haiying, Zhang

    2010-09-01

    A 6-9 GHz ultra-wideband CMOS power amplifier (PA) for the high frequency band of China's UWB standard is proposed. Compared with the conventional band-pass filter wideband input matching methodology, the number of inductors is saved by the resistive feedback complementary amplifying topology presented. The output impendence matching network utilized is very simple but efficient at the cost of only one inductor. The measured S22 far exceeds that of similar work. The PA is designed and fabricated with TSMC 0.18 μm 1P6M RF CMOS technology. The implemented PA achieves a power gain of 10 dB with a ripple of 0.6 dB, and S11 < -10 dB over 6-9 GHz, S22 < -35 dB over 4-10 GHz. The measured output power at the 1 dB compression point is over 3.5 dBm from 6 to 9 GHz. The PA dissipates a total power of 21 mW from a 1.8 V power supply. The chip size is 1.1 × 0.8 mm2.

  19. One Teacher's Trash Is Another's Treasure.

    Science.gov (United States)

    Dyrud, Marilyn A.

    1990-01-01

    Analyzes the junk mail received by the author. Describes a class activity in which students, working in small groups, discuss particular pieces of junk mail and decide which elements of persuasion are the most effective. Describes how students design their own flyers or letters to advertise something. (RS)

  20. A Full Plate for Schools.

    Science.gov (United States)

    Marlowe, John

    2002-01-01

    As of summer 2001, at least 12 states are deep-sixing junk foods in schools. Schools face an uphill battle on nutrition education. Commercials promoting junk food seem ubiquitous, and children are spending too many inactive hours watching television. Major challenges include the open-campus lunch period and cash-strapped schools using profits from…

  1. 23 CFR 751.13 - Control measures.

    Science.gov (United States)

    2010-04-01

    ... of 1969 (42 U.S.C. 4321), recycling of junk and scrap is to be encouraged to the greatest extent practicable in the implementation of the junkyard control program. Recycling should be considered in conjunction with other control measures. To facilitate recycling, junk or scrap should be moved to...

  2. Listening to Historys Rhyme:Preparing the United States Army for Future Irregular Warfare

    Science.gov (United States)

    2014-04-01

    December 2007), 10. 44. Mission: Readiness, Too Fat to Fight: Retired Military Leaders Want Junk Food Out of Schools (Washington, DC, April 2010), 2...Politics and Strategy 50, no. 1 (February-March 2008): 19-30. Mission: Readiness. Too Fat to Fight: Retired Military Leaders Want Junk Food Out

  3. Food in the Schools, Part I. Options in Education, Program #75.

    Science.gov (United States)

    George Washington Univ., Washington, DC. Inst. for Educational Leadership.

    This document presents the program transcripts of a weekly series broadcast by member stations of National Public Radio. The program focuses on food in the schools. It addresses the following issues: plate waste in Chicago and Dallas; banning junk food and vending machines; the results of a vending machine junk food ban in West Virginia;…

  4. Talisman Treasures

    Science.gov (United States)

    Surrena, Michelle

    2010-01-01

    Junk is an art teacher's best friend. Everyone has junk, but it takes a special eye to see beyond such unwanted items and give them new purpose. In this article, the author describes a lesson completed with her jewelry/metals class. Inspired by the artwork of Barbara Lenart Kazmer, who incorporates found objects into one-of-a-kind pieces, students…

  5. Realization of Miniaturized Multi-/Wideband Microwave Front-Ends

    Science.gov (United States)

    Al Shamaileh, Khair A.

    The ever-growing demand toward designing microwave front-end components with enhanced access to the radio spectrum (e.g., multi-/wideband functionality) and improved physical features (e.g., miniaturized circuitry, ease and cost of fabrication) is becoming more paramount than ever before. This dissertation proposes new design methodologies, simulations, and experimental validations of passive front-ends (i.e., antennas, couplers, dividers) at microwave frequencies. The presented design concepts optimize both electrical and physical characteristics without degrading the intended performance. The developed designs are essential to the upcoming wireless technologies. The first proposed component is a compact ultra-wideband (UWB) Wilkinson power divider (WPD). The design procedure is accomplished by replacing the uniform transmission lines in each arm of the conventional single-frequency divider with impedance-varying profiles governed by a truncated Fourier series. While such non-uniform transmission lines (NTLs) are obtained through the even-mode analysis, three isolation resistors are optimized in the odd-mode circuit to achieve proper isolation and output ports matching over the frequency range of interest. The proposed design methodology is systematic, and results in single-layered and compact structures. For verification purposes, an equal split WPD is designed, simulated, and measured. The obtained results show that the input and output ports matching as well as the isolation between the output ports are below --10 dB; whereas the transmission parameters vary between --3.2 dB and --5 dB across the 3.1--10.6 GHz band. The designed divider is expected to find applications in UWB antenna diversity, multiple-input-multiple-output (MIMO) schemes, and antenna arrays feeding networks. The second proposed component is a wideband multi-way Bagley power divider (BPD). Wideband functionality is achieved by replacing the single-frequency matching uniform microstrip lines in

  6. Hardware-in-the-loop simulation technology of wide-band radar targets based on scattering center model

    Institute of Scientific and Technical Information of China (English)

    Huang Hao; Pan Minghai; Lu Zhijun

    2015-01-01

    Hardware-in-the-loop (HWIL) simulation technology can verify and evaluate the radar by simulating the radio frequency environment in an anechoic chamber. The HWIL simulation technology of wide-band radar targets can accurately generate wide-band radar target echo which stands for the radar target scattering characteristics and pulse modulation of radar transmitting sig-nal. This paper analyzes the wide-band radar target scattering properties first. Since the responses of target are composed of many separate scattering centers, the target scattering characteristic is restructured by scattering centers model. Based on the scattering centers model of wide-band radar target, the wide-band radar target echo modeling and the simulation method are discussed. The wide-band radar target echo is reconstructed in real-time by convoluting the transmitting signal to the target scattering parameters. Using the digital radio frequency memory (DRFM) system, the HWIL simulation of wide-band radar target echo with high accuracy can be actualized. A typical wide-band radar target simulation is taken to demonstrate the preferable simulation effect of the reconstruction method of wide-band radar target echo. Finally, the radar target time-domain echo and high-resolution range profile (HRRP) are given. The results show that the HWIL simulation gives a high-resolution range distribution of wide-band radar target scattering centers.

  7. Wideband monolithically integrated front-end subsystems and components

    Science.gov (United States)

    Mruk, Joseph Rene

    This thesis presents the analysis, design, and measurements of passive, monolithically integrated, wideband recta-coax and printed circuit board front-end components. Monolithic fabrication of antennas, impedance transformers, filters, and transitions lowers manufacturing costs by reducing assembly time and enhances performance by removing connectors and cabling between the devices. Computational design, fabrication, and measurements are used to demonstrate the capabilities of these front-end assemblies. Two-arm wideband planar log-periodic antennas fed using a horizontal feed that allows for filters and impedance transformers to be readily fabricated within the radiating region of the antenna are demonstrated. At microwave frequencies, low-cost printed circuit board processes are typically used to produce planar devices. A 1.8 to 11 GHz two-arm planar log-periodic antenna is designed with a monolithically integrated impedance transformer. Band rejection methods based on modifying the antenna aperture, use of an integrated filter, and the application of both methods are investigated with realized gain suppressions of over 25 dB achieved. The ability of standard circuit board technology to fabricate millimeter-wave devices up to 110 GHz is severely limited. Thin dielectrics are required to prevent the excitation of higher order modes in the microstrip substrate. Fabricating the thin line widths required for the antenna aperture also becomes prohibitively challenging. Surface micro-machining typically used in the fabrication of MEMS devices is capable of producing the extremely small features that can be used to fabricate antennas extending through W-band. A directly RF fed 18 to 110 GHz planar log-periodic antenna is developed. The antenna is fabricated with an integrated impedance transformer and additional transitions for measurement characterization. Singly terminated low-loss wideband millimeter-wave filters operating over V- and W- band are developed. High

  8. Wide-Band Microwave Receivers Using Photonic Processing

    Science.gov (United States)

    Matsko, Andrey; Maleki, Lute; Itchenko, Vladimir; Yu, Nan; Strekalov, Dmitry; Savchenkov, Anatoliy

    2008-01-01

    In wide-band microwave receivers of a type now undergoing development, the incoming microwave signals are electronically preamplified, then frequency-up-converted to optical signals that are processed photonically before being detected. This approach differs from the traditional approach, in which incoming microwave signals are processed by purely electronic means. As used here, wide-band microwave receivers refers especially to receivers capable of reception at any frequency throughout the range from about 90 to about 300 GHz. The advantage expected to be gained by following the up-conversion-and-photonic-processing approach is the ability to overcome the limitations of currently available detectors and tunable local oscillators in the frequency range of interest. In a receiver following this approach (see figure), a preamplified incoming microwave signal is up-converted by the method described in the preceeding article. The frequency up-converter exploits the nonlinearity of the electromagnetic response of a whispering gallery mode (WGM) resonator made of LiNbO3. Up-conversion takes place by three-wave mixing in the resonator. The WGM resonator is designed and fabricated to function simultaneously as an electro-optical modulator and to exhibit resonance at the microwave and optical operating frequencies plus phase matching among the microwave and optical signals circulating in the resonator. The up-conversion is an efficient process, and the efficiency is enhanced by the combination of microwave and optical resonances. The up-converted signal is processed photonically by use of a tunable optical filter or local oscillator, and is then detected. Tunable optical filters can be made to be frequency agile and to exhibit high resonance quality factors (high Q values), thereby making it possible to utilize a variety of signal-processing modalities. Therefore, it is anticipated that when fully developed, receivers of this type will be compact and will be capable of both

  9. High frequency wide-band transformer uses coax to achieve high turn ratio and flat response

    Science.gov (United States)

    De Parry, T.

    1966-01-01

    Center-tap push-pull transformer with toroidal core helically wound with a single coaxial cable creates a high frequency wideband transformer. This transformer has a high-turn ratio, a high coupling coefficient, and a flat broadband response.

  10. Ultra wideband reflector antenna log-periodic feed with operating frequency range 1–20 GHz.

    Directory of Open Access Journals (Sweden)

    F. F. Dubrovka

    2010-05-01

    Full Text Available Results of modeling and optimization of electric characteristics of ultra wideband reflector antenna log-periodic feed, based on two log-periodic antennas array for operating over frequency range 1 -20 GHz, are presented.

  11. Reconfigurable, Wideband Radar Transceiver and Antenna for P-band Stretch Processing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — IAI proposes to develop a Reconfigurable Wideband Radar Transceiver, with direct digital synthesis of P-band radar frequencies, novel high bandwidth P-band antenna...

  12. Ultra-Wideband Transceiver for Integrated Communication and Relative Navigation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this project is to develop an innovative way of using Time Modulated Ultra Wideband (TM-UWB) transceivers (radios) to provide high performance integrated...

  13. Software Radio Implementation of RF Short-Wave Wideband Channel Simulator

    Institute of Scientific and Technical Information of China (English)

    DINGYahui; GANLiangcai; XIELing

    2005-01-01

    A novel radio frequency short-wave wideband channel simulator which can be used to evaluate wideband SW communication system performance over shortwave channel with time-variant and dispersive property, is proposed in this paper. The channel simulator consists of RF transmitting, receiving module and baseband digital signal processing module. In particular, a wideband channel model is introduced into this project that can exhibit various short-wave characteristic such as delay spread, Doppler shift, Doppler spread and all kinds of noise and interference. At the same time, this paper makes a great improvement on SW wideband channel model proposed in Ref.[2] and utilizes some idea of software radio to design the channel simulator's RF part. Therefore, the channel simulator described in the paper can be applicable to not only theoretical research, but also practical application.

  14. WISM - A Wideband Instrument for Snow Measurement: Past Accomplishments, Current Status, and Path Forward

    Science.gov (United States)

    Bonds, Quenton; Racette, Paul; Durham, Tim (Principal Investigator)

    2016-01-01

    Presented are the prior accomplishments, current status and path forward for GSFC's Wideband Instrument for Snow Measurement (WISM). This work is a high level overview of the project, presented via Webinar to the IEEE young professionals.

  15. Design of a High Linearity Four-Quadrant Analog Multiplier in Wideband Frequency Range

    Directory of Open Access Journals (Sweden)

    Abdul kareem Mokif Obais

    2017-05-01

    Full Text Available In this paper, a voltage mode four quadrant analog multiplier in the wideband frequency rangeis designed using a wideband operational amplifier (OPAMP and squaring circuits. The wideband OPAMP is designed using 10 identical NMOS transistorsand operated with supply voltages of ±12V. Two NMOS transistors and two wideband OPAMP are utilized in the design of the proposed squaring circuit. All the NMOS transistors are based on 0.35µm NMOStechnology. The multiplier has input and output voltage ranges of ±10 V, high range of linearity from -10 V to +10 V, and cutoff frequency of about 5 GHz. The proposed multiplier is designed on PSpice in Orcad 16.6

  16. Ultra-wideband Radar Methods and Techniques of Medical Sensing and Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Paulson, C N; Chang, J T; Romero, C E; Watson, J; Pearce, F J; Levin, N

    2005-10-07

    Ultra-wideband radar holds great promise for a variety of medical applications. We have demonstrated the feasibility of using ultra-wideband sensors for detection of internal injuries, monitoring of respiratory and cardiac functions, and continuous non-contact imaging of the human body. Sensors are low-power, portable, and do not require physical contact with the patient. They are ideal for use by emergency responders to make rapid diagnosis and triage decisions. In the hospital, vital signs monitoring and imaging application could improve patient outcomes. In this paper we present an overview of ultra-wideband radar technology, discuss key design tradeoffs, and give examples of ongoing research in applying ultra-wideband technology to the medical field.

  17. Versatile Wideband Balanced Detector for Quantum Optical Homodyne Tomography

    CERN Document Server

    Kumar, Ranjeet; MacRae, Andrew; Cairns, E; Huntington, E H; Lvovsky, A I

    2011-01-01

    We present a comprehensive theory and an easy to follow method for the design and construction of a wideband homodyne detector for time-domain quantum measurements. We show how one can evaluate the performance of a detector in a specific time-domain experiment based on electronic spectral characteristic of that detector. We then present and characterize a high-performance detector constructed using inexpensive, commercially available components such as low-noise high-speed operational amplifiers and high-bandwidth photodiodes. Our detector shows linear behavior up to a level of over 13 dB clearance between shot noise and electronic noise, in the range from DC to 100 MHz. The detector can be used for measuring quantum optical field quadratures both in the continuous-wave and pulsed regimes with pulse repetition rates up to about 250 MHz.

  18. Cooperative Wideband Spectrum Sensing for the Centralized Cognitive Radio Network

    CERN Document Server

    Zhang, Peng

    2011-01-01

    Various primary user (PU) radios have been allocated into fixed frequency bands in the whole spectrum. A cognitive radio network (CRN) should be able to perform the wideband spectrum sensing (WSS) to detect temporarily unoccupied frequency bands. We summarize four occupancy features for the frequency bands. 1. The occupancy is sparse; 2. The frequency band allocation information is fixed and common; 3. There are three categories for the frequency band usages; 4. The occupied frequency bands are common in the CRN. For the first time, we consider all features as the prior knowledge in the compressed sensing based cooperative WSS (CWSS) algorithm design for a centralized CRN. We propose a modified orthogonal matching pursuit (Mod-OMP) algorithm and a modified simultaneous orthogonal matching pursuit (Mod-SOMP) algorithm for the CWSS. We compare the CWSS performance of Mod-OMP/Mod-SOMP with the original OMP/SOMP and show the performance improvements.

  19. A Novel Ropes-DrivenWideband Piezoelectric Vibration Energy Harvester

    Directory of Open Access Journals (Sweden)

    Jinhui Zhang

    2016-12-01

    Full Text Available This paper presents a novel piezoelectric vibration energy harvester (PVEH in which a high-frequency generating beam (HFGB is driven by an array of low-frequency driving beams (LFDBs using ropes. Two mechanisms based on frequency upconversion and multimodal harvesting work together to broaden the frequency bandwidth of the proposed vibration energy harvester (VEH. The experimental results show that the output power of generating beam (GB remains unchanged with the increasing number of driving beams (DBs, compared with the traditional arrays of beams vibration energy harvester (AB-VEH, and the output power and bandwidth behavior can be adjusted by parameters such as acceleration, rope margin, and stiffness of LFDBs, which shows the potential to achieve unlimited wideband vibration energy-harvesting for a variable environment.

  20. Wideband and UWB Antennas for Wireless Applications: A Comprehensive Review

    Directory of Open Access Journals (Sweden)

    Renato Cicchetti

    2017-01-01

    Full Text Available A comprehensive review concerning the geometry, the manufacturing technologies, the materials, and the numerical techniques, adopted for the analysis and design of wideband and ultrawideband (UWB antennas for wireless applications, is presented. Planar, printed, dielectric, and wearable antennas, achievable on laminate (rigid and flexible, and textile dielectric substrates are taken into account. The performances of small, low-profile, and dielectric resonator antennas are illustrated paying particular attention to the application areas concerning portable devices (mobile phones, tablets, glasses, laptops, wearable computers, etc. and radio base stations. This information provides a guidance to the selection of the different antenna geometries in terms of bandwidth, gain, field polarization, time-domain response, dimensions, and materials useful for their realization and integration in modern communication systems.

  1. A Wideband Circularly Polarized Pixelated Dielectric Resonator Antenna

    Science.gov (United States)

    Trinh-Van, Son; Yang, Youngoo; Lee, Kang-Yoon; Hwang, Keum Cheol

    2016-01-01

    The design of a wideband circularly polarized pixelated dielectric resonator antenna using a real-coded genetic algorithm (GA) is presented for far-field wireless power transfer applications. The antenna consists of a dielectric resonator (DR) which is discretized into 8 × 8 grid DR bars. The real-coded GA is utilized to estimate the optimal heights of the 64 DR bars to realize circular polarization. The proposed antenna is excited by a narrow rectangular slot etched on the ground plane. A prototype of the proposed antenna is fabricated and tested. The measured −10 dB reflection and 3 dB axial ratio bandwidths are 32.32% (2.62–3.63 GHz) and 14.63% (2.85–3.30 GHz), respectively. A measured peak gain of 6.13 dBic is achieved at 3.2 GHz. PMID:27563897

  2. Near-Field Cross Section Imaging of Wideband Millimeter Wave

    Directory of Open Access Journals (Sweden)

    Kan Yingzhi

    2016-01-01

    Full Text Available Near-field millimeter wave imaging has been a hot topic recent years for its importance applications in the area of anti-terrorism. The penetrating characteristic of millimeter wave is of significant importance to security, such as the concealed weapons detection, ground-penetrating radar imaging, through-barrier imaging and so on. Cross section imaging is a basic aspect for near-field millimeter wave imaging, which includes antenna array distribution and wideband signal processing. This paper utilizes back projection method in space area to realize ultra-band nearfield cross section imaging. We induce two dimensional direction integral formulas to obtain the reconstruction image of the near-field imaging area, and the simulation results validate the effectiveness of this imaging algorithm.

  3. Micro-Doppler processing for ultra-wideband radar data

    Science.gov (United States)

    Smith, Graeme E.; Ahmad, Fauzia; Amin, Moeness G.

    2012-06-01

    In this paper, we describe an operational pulse Doppler radar imaging system for indoor target localization and classification, and show how a target's micro-Doppler signature (μDS) can be processed when ultra-wideband (UWB) waveforms are employed. Unlike narrowband radars where time-frequency signal representations can be applied to reveal the target time-Doppler frequency signatures, the UWB system permits joint range-time-frequency representation (JRTFR). JRTFR outputs the data in a 3D domain representing range, frequency, and time, allowing both the μDS and high range resolution (HRR) signatures to be observed. We delineate the relationship between the μDS and the HRR signature, showing how they would form a complimentary joint feature for classification. We use real-data to demonstrate the effectiveness of the UWB pulse-Doppler radar, combined with nonstationary signal analyses, in gaining valuable insights into human positioning and motions.

  4. Fundamental Limits of Wideband Localization - Part I: A General Framework

    CERN Document Server

    Shen, Yuan

    2010-01-01

    The availability of positional information is of great importance in many commercial, public safety, and military applications. The coming years will see the emergence of location-aware networks with sub-meter accuracy, relying on accurate range measurements provided by wide bandwidth transmissions. In this two-part paper, we determine the fundamental limits of localization accuracy of wideband wireless networks in harsh multipath environments. We first develop a general framework to characterize the localization accuracy of a given node here and then extend our analysis to cooperative location-aware networks in Part II. In this paper, we characterize localization accuracy in terms of a performance measure called the squared position error bound (SPEB), and introduce the notion of equivalent Fisher information to derive the SPEB in a succinct expression. This methodology provides insights into the essence of the localization problem by unifying localization information from individual anchors and information ...

  5. Macro-motion detection using ultra-wideband impulse radar.

    Science.gov (United States)

    Xin Li; Dengyu Qiao; Ye Li

    2014-01-01

    Radar has the advantage of being able to detect hidden individuals, which can be used in homeland security, disaster rescue, and healthcare monitoring-related applications. Human macro-motion detection using ultra-wideband impulse radar is studied in this paper. First, a frequency domain analysis is carried out to show that the macro-motion yields a bandpass signal in slow-time. Second, the FTFW (fast-time frequency windowing), which has the advantage of avoiding the measuring range reduction, and the HLF (high-pass linear-phase filter), which can preserve the motion signal effectively, are proposed to preprocess the radar echo. Last, a threshold decision method, based on the energy detector structure, is presented.

  6. Mathematic principle of active jamming against wideband LFM radar

    Institute of Scientific and Technical Information of China (English)

    Shixian Gong; Xizhang Wei; Xiang Li; Yongshun Ling

    2015-01-01

    The inherent mathematic principle of active jamming against the wideband linear frequency modulated (LFM) radar is investigated. According to different generation strategies, the active jamming methods are reclassified into three groups, i.e., non-coherent jamming (NCJ), convolution jamming (CJ) and mul-tiplying jamming (MJ). Based on the classification, the mathematic principles of different active jamming groups are put forward, which describe the relationships between the modulated signals and the jamming results. The advantages and disadvantages of different groups are further analyzed, which provides a new perspective for the study of jamming/anti-jamming methods and a potential for engineers to integrate similar jamming methods into one jam-mer platform. The analyses and simulation results of some typical active jamming methods prove the validity of the proposed mathe-matics principle.

  7. Resilience of LTE networks against smart jamming attacks: Wideband model

    KAUST Repository

    Aziz, Farhan M.

    2015-12-03

    LTE/LTE-A networks have been successfully providing advanced broadband services to millions of users worldwide. Lately, it has been suggested to use LTE networks for mission-critical applications like public safety, smart grid and military communications. We have previously shown that LTE networks are vulnerable to Denial-of-Service (DOS) and loss of service attacks from smart jammers. In this paper, we extend our previous work on resilience of LTE networks to wideband multipath fading channel, SINR estimation in frequency domain and computation of utilities based on observable parameters under the framework of single-shot and repeated games with asymmetric information. In a single-shot game formulation, network utility is severely compromised at its solutions, i.e. at the Nash Equilibria (NE). We propose evolved repeated-game strategy algorithms to combat smart jamming attacks that can be implemented in existing deployments using current technology. © 2015 IEEE.

  8. A GPU-Based Wide-Band Radio Spectrometer

    CERN Document Server

    Chennamangalam, Jayanth; Jones, Glenn; Chen, Hong; Ford, John; Kepley, Amanda; Lorimer, D R; Nie, Jun; Prestage, Richard; Roshi, D Anish; Wagner, Mark; Werthimer, Dan

    2014-01-01

    The Graphics Processing Unit (GPU) has become an integral part of astronomical instrumentation, enabling high-performance online data reduction and accelerated online signal processing. In this paper, we describe a wide-band reconfigurable spectrometer built using an off-the-shelf GPU card. This spectrometer, when configured as a polyphase filter bank (PFB), supports a dual-polarization bandwidth of up to 1.1 GHz (or a single-polarization bandwidth of up to 2.2 GHz) on the latest generation of GPUs. On the other hand, when configured as a direct FFT, the spectrometer supports a dual-polarization bandwidth of up to 1.4 GHz (or a single-polarization bandwidth of up to 2.8 GHz).

  9. Low sampling frequency processing for ultra-wideband signals

    Science.gov (United States)

    Wan, Yonglun; Si, Qiang; Lu, Youxin; Wang, Hong; Wang, Xuegang

    2005-11-01

    Ultra-wideband (UWB) signals are widely used in radar, navigation and satellite communications. It is rather difficult to process UWB signals. In this paper we adopt dechirp pulse compression method to process the received UWB linear frequency modulated (LFM) signals. UWB signals are converted into signals with frequency components that are proportional to the relative range between the target and the reference target. It means to select low-speed analog-to-digital converters (ADC) for sampling UWB signals. The simulation results show that LFM signal with 600MHz center frequency, 200MHz bandwidth and 30usec pulse width can be processed under 70MHz sampling frequency by means of the method.

  10. A wideband combined transducer for measuring system in sound tube

    Institute of Scientific and Technical Information of China (English)

    PAN Yaozong; MO Xiping; LIU Yongping; CUI Zheng; ZHANG Tonggen

    2012-01-01

    A wideband transducer for sound tube system is presented, which combines longitudinal transducer and Class IV flextensional transducer to improve the performance at low frequency and broaden the working band. The equivalent circuit is obtained and used to analyze the coupling mechanism between longitudinal transducer and flextensional transducer. A prototype of the transducer is developed after optimizing the electro-acoustic performances by Finite Element Method. The standing wave in the sound tube stimulated by this transducer has been studied and the sound absorbing coefficients of two acoustic materials samples are measured using this sound tube, which shows that the transducer can meet the requirements of acoustic material measurement with the working band ranging from 1.4 kHz to 23 kHz.

  11. A Wideband Circularly Polarized Pixelated Dielectric Resonator Antenna.

    Science.gov (United States)

    Trinh-Van, Son; Yang, Youngoo; Lee, Kang-Yoon; Hwang, Keum Cheol

    2016-08-23

    The design of a wideband circularly polarized pixelated dielectric resonator antenna using a real-coded genetic algorithm (GA) is presented for far-field wireless power transfer applications. The antenna consists of a dielectric resonator (DR) which is discretized into 8 × 8 grid DR bars. The real-coded GA is utilized to estimate the optimal heights of the 64 DR bars to realize circular polarization. The proposed antenna is excited by a narrow rectangular slot etched on the ground plane. A prototype of the proposed antenna is fabricated and tested. The measured -10 dB reflection and 3 dB axial ratio bandwidths are 32.32% (2.62-3.63 GHz) and 14.63% (2.85-3.30 GHz), respectively. A measured peak gain of 6.13 dBic is achieved at 3.2 GHz.

  12. Optimal Time-Reversed Wideband Signals for Distributed Sensing

    CERN Document Server

    Kim, Jerry; Mokole, Eric

    2015-01-01

    This paper considers a distributed wave-based sensing system that probes a scene consisting of multiple interacting idealized targets. Each sensor is a collocated transmit-receive pair that is capable of transmitting arbitrary wideband waveforms. We address the problem of finding the space-time transmit waveform that provides the best target detection performance in the sense of maximizing the energy scattered back into the receivers. Our approach is based on earlier work that constructed the solution by an iterative time-reversal (TR) process. In particular, for the case of idealized point-like scatterers in free space, we examine the frequency dependence of the eigenvalues of the TR operator, and we show that their behavior depends on constructive and destructive interference of the waves traveling along different paths. In addition, we show how these eigenvalues are connected to the poles of the Singularity Expansion Method. Our study of the frequency behavior distinguishes this work from most previous TR ...

  13. Ultra-wideband noise radar based on optical waveform generation

    Science.gov (United States)

    Grodensky, Daniel; Kravitz, Daniel; Zadok, Avi

    2012-06-01

    A microwave-photonic, ultra-wideband (UWB) noise radar system is proposed and demonstrated. The system brings together photonic generation of UWB waveforms and fiber-optic distribution. The use of UWB noise provides high ranging resolution and better immunity to interception and jamming. Distribution over fibers allows for the separation the radar-operating personnel and equipment from the location of the front-end. The noise waveforms are generated using the amplified spontaneous emission that is associated with stimulated Brillouin scattering in a standard optical fiber, or with an erbium-doped fiber amplifier. Our experiments demonstrate a proof of concept for an integrated radar system, driven by optically generated UWB noise waveforms of more than 1 GHz bandwidth that are distributed over 10 km distance. The detection of concealed metallic object and the resolving of two targets with the anticipated ranging resolution are reported.

  14. Model-Based Radar Power Calculations for Ultra-Wideband (UWB) Synthetic Aperture Radar (SAR)

    Science.gov (United States)

    2013-06-01

    performance in complex scenarios. Among these scenarios are ground penetrating radar and forward-looking radar for landmine and improvised explosive...Model-Based Radar Power Calculations for Ultra-Wideband (UWB) Synthetic Aperture Radar (SAR) by Traian Dogaru ARL-TN-0548 June 2013...2013 Model-Based Radar Power Calculations for Ultra-Wideband (UWB) Synthetic Aperture Radar (SAR) Traian Dogaru Sensors and Electron

  15. All-Digital Wideband Space-Frequency Beamforming for the SKA Aperture Array

    CERN Document Server

    Khlebnikov, Vasily A; Armstrong, Richard P; Jones, Michael E

    2010-01-01

    In this paper, we consider the problem of optimum multi-domain real-time beamforming and high-precision beam pattern positioning in application to very large wideband array antennas, particularly to the Square Kilometre Array (SKA) aperture array antenna. We present a new structure for wideband space-frequency beamforming and beamsteering that maximizes detectability of cosmic signals over the array operational frequency range.

  16. Ultra-Wideband Harmonic Radar for Locating Radio-Frequency Electronics

    Science.gov (United States)

    2015-03-01

    Ultra-Wideband Harmonic Radar for Locating Radio- Frequency Electronics by Gregory J Mazzaro, Kyle A Gallagher, Albert R Owens, Kelly D...Department of the Army position unless so designated by other authorized documents. Citation of manufacturer’s or trade names does not constitute an...Research Laboratory Adelphi, MD 20783-1138 ARL-TR-7256 March 2015 Ultra-Wideband Harmonic Radar for Locating Radio- Frequency Electronics

  17. Specifying and calibrating instrumentations for wideband electronic power measurements. [in switching circuits

    Science.gov (United States)

    Lesco, D. J.; Weikle, D. H.

    1980-01-01

    The wideband electric power measurement related topics of electronic wattmeter calibration and specification are discussed. Tested calibration techniques are described in detail. Analytical methods used to determine the bandwidth requirements of instrumentation for switching circuit waveforms are presented and illustrated with examples from electric vehicle type applications. Analog multiplier wattmeters, digital wattmeters and calculating digital oscilloscopes are compared. The instrumentation characteristics which are critical to accurate wideband power measurement are described.

  18. Direction of Arrival Estimation of Wide-Band Emitters

    Science.gov (United States)

    Hojati, Shahram

    Most published algorithms for DOA (Direction of Arrival) estimation of incoming signals by spatially dispersed electromagnetic or acoustic sources rely on the narrow -band approximation. This approach is inadequate from at least two standpoints. First, the approximation breaks down in many practical situation of interest; and, second, it inhibits the exploitation of intrinsic degrees of freedom of wide-band emitters to achieve additional improvements in angular resolution. In this dissertation the direction of arrival estimation problem is examined without employing the customary narrow-band restriction. A class of algorithms that has been successfully employed for DOA estimation of narrow-band signals exploits the eigenstructure of the array correlation matrix. Although they are sub-optimum, these algorithms enjoy substantial computational advantages over the optimum maximum likelihood approaches. It is shown that the frequency domain representation of the array output leads to a spectral coherence matrix that exhibits an eigenstructure similar to the correlation matrix used under the narrow-band approximation. As a consequence, narrow-band eigenbased algorithms can be adopted to DOA estimation without restrictions on signal bandwidth. The Spectral Coherence Technique (SCT) is applied in conjunction with the MUSIC, the Root-Music and a modified form of the Pisarenko algorithms to DOA estimation of wide -band emitters using linear arrays. Simulation indicate that all three algorithms afford comparable performance: the variance of the angle of arrival estimate decreases approximately inversely with the signal time bandwidth product. They differ, however, with regard to computational efficiency. In particular, the wide-band version of the algorithm MUSIC requires substantially more processing time than either the Pisarenko or the Root-Music algorithms. These algorithms also yield comparable performance to an alternative approach using frequency segmentation (Wi

  19. Broadband Cooperative Spectrum Sensing Based on Distributed Modulated Wideband Converter

    Directory of Open Access Journals (Sweden)

    Ziyong Xu

    2016-09-01

    Full Text Available The modulated wideband converter (MWC is a kind of sub-Nyquist sampling system which is developed from compressed sensing theory. It accomplishes highly accurate broadband sparse signal recovery by multichannel sub-Nyquist sampling sequences. However, when the number of sparse sub-bands becomes large, the amount of sampling channels increases proportionally. Besides, it is very hard to adjust the number of sampling channels when the sparsity changes, because its undersampling board is designed by a given sparsity. Such hardware cost and inconvenience are unacceptable in practical applications. This paper proposes a distributed modulated wideband converter (DMWC scheme innovatively, which regards one sensor node as one sampling channel and combines MWC technology with a broadband cooperative spectrum sensing network perfectly. Being different from the MWC scheme, DMWC takes phase shift and transmission loss into account in the input terminal, which are unavoidable in practical application. Our scheme is not only able to recover the support of broadband sparse signals quickly and accurately, but also reduces the hardware cost of the single node drastically. Theoretical analysis and numerical simulations show that phase shift has no influence on the recovery of frequency support, but transmission loss degrades the recovery performance to a different extent. Nevertheless, we can increase the amount of cooperative nodes and select satisfactory nodes by a different transmission distance to improve the recovery performance. Furthermore, we can adjust the amount of cooperative nodes flexibly when the sparsity changes. It indicates DMWC is extremely effective in the broadband cooperative spectrum sensing network.

  20. Experimental verification of color flow imaging based on wideband Doppler method.

    Science.gov (United States)

    Tanaka, Naohiko

    2014-01-01

    The purpose of this study is to eliminate the aliasing in color flow imaging. The wideband Doppler method is applied to generate a color flow image, and the validity of the method is experimentally confirmed. The single beam experiment is carried out to confirm the velocity estimation based on the wideband Doppler method. The echo data for the conventional pulsed Doppler method and the wideband Doppler method are obtained using a flow model, and the estimated velocity for each method is compared. The color flow images for each method are also generated using several types of flow model. The generated images are compared, and the characteristics of the imaging based on the wideband Doppler method are discussed. The high velocity beyond the Nyquist limit is successfully estimated by the wideband Doppler method, and the availability in low velocity estimation is also confirmed. The aliasing in color flow images is eliminated, and the generated images show the significance of the elimination of the aliasing in the flow imaging. The aliasing in color flow imaging can be eliminated by the wideband Doppler method. This technique is useful for the exact understanding of blood flow dynamics.

  1. Reducing high calorie snack food in young adults: a role for social norms and health based messages

    Science.gov (United States)

    2013-01-01

    Background Consumption of high calorie junk foods has increased recently, especially among young adults and higher intake may cause weight gain. There is a need to develop public health approaches to motivate people to reduce their intake of junk food. Objective To assess the effect of health and social norm messages on high calorie snack food intake (a type of junk food) as a function of usual intake of junk food. Design In a between-subjects design, 129 young adults (45 men and 84 women, mean age = 22.4 years, SD = 4.5) were assigned to one of three conditions: 1) a social norm condition, in which participants saw a message about the junk food eating habits of others; 2) a health condition, in which participants saw a message outlining the health benefits of reducing junk food consumption and; 3) a control condition, in which participants saw a non-food related message. After exposure to the poster messages, participants consumed a snack and the choice and amount of snack food consumed was examined covertly. We also examined whether usual intake of junk food moderated the effect of message type on high calorie snack food intake. Results The amount of high calorie snack food consumed was significantly lower in both the health and the social norm message condition compared with the control message condition (36% and 28%, both p junk food. Conclusions Messages about the health effects of junk food and social normative messages about intake of junk food can motivate people to reduce their consumption of high calorie snack food. PMID:23738741

  2. Reducing high calorie snack food in young adults: a role for social norms and health based messages.

    Science.gov (United States)

    Robinson, Eric; Harris, Ellis; Thomas, Jason; Aveyard, Paul; Higgs, Suzanne

    2013-06-05

    Consumption of high calorie junk foods has increased recently, especially among young adults and higher intake may cause weight gain. There is a need to develop public health approaches to motivate people to reduce their intake of junk food. To assess the effect of health and social norm messages on high calorie snack food intake (a type of junk food) as a function of usual intake of junk food. In a between-subjects design, 129 young adults (45 men and 84 women, mean age = 22.4 years, SD = 4.5) were assigned to one of three conditions: 1) a social norm condition, in which participants saw a message about the junk food eating habits of others; 2) a health condition, in which participants saw a message outlining the health benefits of reducing junk food consumption and; 3) a control condition, in which participants saw a non-food related message. After exposure to the poster messages, participants consumed a snack and the choice and amount of snack food consumed was examined covertly. We also examined whether usual intake of junk food moderated the effect of message type on high calorie snack food intake. The amount of high calorie snack food consumed was significantly lower in both the health and the social norm message condition compared with the control message condition (36% and 28%, both p food or energy intake between the health and social norm message conditions. There was no evidence that the effect of the messages depended upon usual consumption of junk food. Messages about the health effects of junk food and social normative messages about intake of junk food can motivate people to reduce their consumption of high calorie snack food.

  3. Ultra-Wideband Optical Modulation Spectrometer (OMS) Development: Study of the Optical Setup of a Wide-Band Optical Modulation Spectrometer

    Science.gov (United States)

    Tolls, Volker; Stringfellow, Guy (Technical Monitor)

    2001-01-01

    The purpose of this study is to advance the design of the optical setup for a wide-band Optical Modulation Spectrometer (OMS) for use with astronomical heterodyne receiver systems. This report describes the progress of this investigation achieved from March until December 2001.

  4. First results from the Cluster wideband plasma wave investigation

    Directory of Open Access Journals (Sweden)

    D. A. Gurnett

    Full Text Available In this report we present the first results from the Cluster wideband plasma wave investigation. The four Cluster spacecraft were successfully placed in closely spaced, high-inclination eccentric orbits around the Earth during two separate launches in July – August 2000. Each spacecraft includes a wideband plasma wave instrument designed to provide high-resolution electric and magnetic field wave-forms via both stored data and direct downlinks to the NASA Deep Space Network. Results are presented for three commonly occurring magnetospheric plasma wave phenomena: (1 whistlers, (2 chorus, and (3 auroral kilometric radiation. Lightning-generated whistlers are frequently observed when the spacecraft is inside the plasmasphere. Usually the same whistler can be detected by all spacecraft, indicating that the whistler wave packet extends over a spatial dimension at least as large as the separation distances transverse to the magnetic field, which during these observations were a few hundred km. This is what would be expected for nonducted whistler propagation. No case has been found in which a strong whistler was detected at one spacecraft, with no signal at the other spacecraft, which would indicate ducted propagation. Whistler-mode chorus emissions are also observed in the inner region of the magnetosphere. In contrast to lightning-generated whistlers, the individual chorus elements seldom show a one-to-one correspondence between the spacecraft, indicating that a typical chorus wave packet has dimensions transverse to the magnetic field of only a few hundred km or less. In one case where a good one-to-one correspondence existed, significant frequency variations were observed between the spacecraft, indicating that the frequency of the wave packet may be evolving as the wave propagates. Auroral kilometric radiation, which is an intense radio emission generated along the auroral field lines, is frequently observed over the polar regions. The

  5. Passive front-ends for wideband millimeter wave electronic warfare

    Science.gov (United States)

    Jastram, Nathan Joseph

    This thesis presents the analysis, design and measurements of novel passive front ends of interest to millimeter wave electronic warfare systems. However, emerging threats in the millimeter waves (18 GHz and above) has led to a push for new systems capable of addressing these threats. At these frequencies, traditional techniques of design and fabrication are challenging due to small size, limited bandwidth and losses. The use of surface micromachining technology for wideband direction finding with multiple element antenna arrays for electronic support is demonstrated. A wideband tapered slot antenna is first designed and measured as an array element for the subsequent arrays. Both 18--36 GHz and 75--110 GHz amplitude only and amplitude/phase two element direction finding front ends are designed and measured. The design of arrays using Butler matrix and Rotman lens beamformers for greater than two element direction finding over W band and beyond using is also presented. The design of a dual polarized high power capable front end for electronic attack over an 18--45 GHz band is presented. To combine two polarizations into the same radiating aperture, an orthomode transducer (OMT) based upon a new double ridge waveguide cross section is developed. To provide greater flexibility in needed performance characteristics, several different turnstile junction matching sections are tested. A modular horn section is proposed to address flexible and ever changing operational requirements, and is designed for performance criteria such as constant gain, beamwidth, etc. A multi-section branch guide coupler and low loss Rotman lens based upon the proposed cross section are also developed. Prototyping methods for the herein designed millimeter wave electronic warfare front ends are investigated. Specifically, both printed circuit board (PCB) prototyping of micromachined systems and 3D printing of conventionally machined horns are presented. A 4--8 GHz two element array with

  6. Design of Analytical Model for Ultra Wideband System

    Directory of Open Access Journals (Sweden)

    Alpana P. Adsul

    2010-05-01

    Full Text Available The UWB (Ultra Wideband technology has drawn phenomenal interest in industry as well as academia.Ultra Wide Band impulse radios are microwave systems that communicate using baseband pulses of veryshort duration. UWB systems transmit information data over a wide frequency spectrum with low powerconsumption and high speed for local area wireless network applications. Unlike the traditional digitalcommunication method based on a carrier wave, UWB is pulse based. Pulse Generation, modulation, andmultiple access are time domain dependent functions. This paper presents the development of analyticalmodel for UWB system. A theoretical reference for UWB system performances is designed in non-idealchannels. In this mathematical models for biphase, pulse–position and hybrid modulation are developed.The detection rules are formulated for detecting signals in AWGN channels. The performance of UWBsystem is described with the help of BER. The BER of a UWB system depends on the modulation schemeand detection method it uses. It is observed that for optimum performance modulation parameterselection is important.

  7. Wideband quin-stable energy harvesting via combined nonlinearity

    Directory of Open Access Journals (Sweden)

    Chen Wang

    2017-04-01

    Full Text Available In this work, we propose a wideband quintuple-well potential piezoelectric-based vibration energy harvester using a combined nonlinearity: the magnetic nonlinearity induced by magnetic force and the piecewise-linearity produced by mechanical impact. With extra stable states compared to other multi-stable harvesters, the quin-stable harvester can distribute its potential energy more uniformly, which provides shallower potential wells and results in lower excitation threshold for interwell motion. The mathematical model of this quin-stable harvester is derived and its equivalent piecewise-nonlinear restoring force is measured in the experiment and identified as piecewise polynomials. Numerical simulations and experimental verifications are performed in different levels of sinusoid excitation ranging from 1 to 25 Hz. The results demonstrate that, with lower potential barriers compared with tri-stable counterpart, the quin-stable arrangement can escape potential wells more easily for doing high-energy interwell motion over a wider band of frequencies. Moreover, by utilizing the mechanical stoppers, this harvester can produce significant output voltage under small tip deflections, which results in a high power density and is especially suitable for a compact MEMS approach.

  8. Ultra Wideband Indoor Positioning Technologies: Analysis and Recent Advances.

    Science.gov (United States)

    Alarifi, Abdulrahman; Al-Salman, AbdulMalik; Alsaleh, Mansour; Alnafessah, Ahmad; Al-Hadhrami, Suheer; Al-Ammar, Mai A; Al-Khalifa, Hend S

    2016-05-16

    In recent years, indoor positioning has emerged as a critical function in many end-user applications; including military, civilian, disaster relief and peacekeeping missions. In comparison with outdoor environments, sensing location information in indoor environments requires a higher precision and is a more challenging task in part because various objects reflect and disperse signals. Ultra WideBand (UWB) is an emerging technology in the field of indoor positioning that has shown better performance compared to others. In order to set the stage for this work, we provide a survey of the state-of-the-art technologies in indoor positioning, followed by a detailed comparative analysis of UWB positioning technologies. We also provide an analysis of strengths, weaknesses, opportunities, and threats (SWOT) to analyze the present state of UWB positioning technologies. While SWOT is not a quantitative approach, it helps in assessing the real status and in revealing the potential of UWB positioning to effectively address the indoor positioning problem. Unlike previous studies, this paper presents new taxonomies, reviews some major recent advances, and argues for further exploration by the research community of this challenging problem space.

  9. Ultra Wideband Indoor Positioning Technologies: Analysis and Recent Advances

    Directory of Open Access Journals (Sweden)

    Abdulrahman Alarifi

    2016-05-01

    Full Text Available In recent years, indoor positioning has emerged as a critical function in many end-user applications; including military, civilian, disaster relief and peacekeeping missions. In comparison with outdoor environments, sensing location information in indoor environments requires a higher precision and is a more challenging task in part because various objects reflect and disperse signals. Ultra WideBand (UWB is an emerging technology in the field of indoor positioning that has shown better performance compared to others. In order to set the stage for this work, we provide a survey of the state-of-the-art technologies in indoor positioning, followed by a detailed comparative analysis of UWB positioning technologies. We also provide an analysis of strengths, weaknesses, opportunities, and threats (SWOT to analyze the present state of UWB positioning technologies. While SWOT is not a quantitative approach, it helps in assessing the real status and in revealing the potential of UWB positioning to effectively address the indoor positioning problem. Unlike previous studies, this paper presents new taxonomies, reviews some major recent advances, and argues for further exploration by the research community of this challenging problem space.

  10. Ultra Wideband Indoor Positioning Technologies: Analysis and Recent Advances †

    Science.gov (United States)

    Alarifi, Abdulrahman; Al-Salman, AbdulMalik; Alsaleh, Mansour; Alnafessah, Ahmad; Al-Hadhrami, Suheer; Al-Ammar, Mai A.; Al-Khalifa, Hend S.

    2016-01-01

    In recent years, indoor positioning has emerged as a critical function in many end-user applications; including military, civilian, disaster relief and peacekeeping missions. In comparison with outdoor environments, sensing location information in indoor environments requires a higher precision and is a more challenging task in part because various objects reflect and disperse signals. Ultra WideBand (UWB) is an emerging technology in the field of indoor positioning that has shown better performance compared to others. In order to set the stage for this work, we provide a survey of the state-of-the-art technologies in indoor positioning, followed by a detailed comparative analysis of UWB positioning technologies. We also provide an analysis of strengths, weaknesses, opportunities, and threats (SWOT) to analyze the present state of UWB positioning technologies. While SWOT is not a quantitative approach, it helps in assessing the real status and in revealing the potential of UWB positioning to effectively address the indoor positioning problem. Unlike previous studies, this paper presents new taxonomies, reviews some major recent advances, and argues for further exploration by the research community of this challenging problem space. PMID:27196906

  11. A linear signal transmission system calibration method of wideband GPR

    Science.gov (United States)

    Wu, Bin; Zhao, Kai; Gu, Ling-jia; Cao, Qiong; Li, Xiao-feng; Zheng, Xing-ming

    2016-09-01

    In VHF pulse Ground Penetrating Radar(GPR) system, the echo pass through the antenna and transmission line circuit, then reach the GPR receiver. Thus the reflection coefficient at the receiver sampling gate interface, which is at the end of the transmission line, is different from the real reflection coefficient of the media at the antenna interface, which could cause the GPR receiving error. The pulse GPR receiver is a wideband system that can't be simply described as traditional narrowband transmission line model. Since the GPR transmission circuit is a linear system, the linear transformation method could be used to analyze the characteristic of the GPR receiving system. A GPR receiver calibration method based on transmission line theory is proposed in this paper, which analyzes the relationship between the reflection coefficients of theory calculation at antenna interface and the measuring data by network analyzer at the sampling gate interface. Then the least square method is introduced to calibrate the transfer function of the GPR receiver transmission circuit. This calibration method can be useful in media quantitative inversion by GPR. When the reflection coefficient at the sampling gate is obtained, the real reflection coefficient of the media at the antenna interface can be easily determined.

  12. Principles and Limitations of Ultra-Wideband FM Communications Systems

    Directory of Open Access Journals (Sweden)

    Kouwenhoven Michiel HL

    2005-01-01

    Full Text Available This paper presents a novel UWB communications system using double FM: a low-modulation index digital FSK followed by a high-modulation index analog FM to create a constant-envelope UWB signal. FDMA techniques at the subcarrier level are exploited to accommodate multiple users. The system is intended for low (1–10 kbps and medium (100–1000 kbps bit rate, and short-range WPAN systems. A wideband delay-line FM demodulator that is not preceded by any limiting amplifier constitutes the key component of the UWBFM receiver. This unusual approach permits multiple users to share the same RF bandwidth. Multipath, however, may limit the useful subcarrier bandwidth to one octave. This paper addresses the performance with AWGN and multipath, the resistance to narrowband interference, as well as the simultaneous detection of multiple FM signals at the same carrier frequency. SPICE and Matlab simulation results illustrate the principles and limitations of this new technology. A hardware demonstrator has been realized and has allowed the confirmation of theory with practical results.

  13. Fast switching wideband rectifying circuit for future RF energy harvesting

    Science.gov (United States)

    Asmeida, Akrem; Mustam, Saizalmursidi Md; Abidin, Z. Z.; Ashyap, A. Y. I.

    2017-09-01

    This paper presents the design and simulation of fast switching microwave rectifying circuit for ultra wideband patch antenna over a dual-frequency band (1.8 GHz for GSM and 2.4 GHz for ISM band). This band was chosen due to its high signal availability in the surrounding environment. New rectifying circuit topology with pair-matching trunks is designed using Advanced Design System (ADS) software. These trunks are interfaced with power divider to achieve good bandwidth, fast switching and high efficiency. The power divider acts as a good isolator between the trunks and its straightforward design structure makes it a good choice for a single feed UWB antenna. The simulated results demonstrate that the maximum output voltage is 2.13 V with an input power of -5 dBm. Moreover, the rectifier offers maximum efficiency of 86% for the input power of -5 dBm at given band, which could easily power up wireless sensor networks (WSN) and other small devices sufficiently.

  14. Time-Domain Diversity in Ultra-Wideband MIMO Communications

    Directory of Open Access Journals (Sweden)

    Alain Sibille

    2005-03-01

    Full Text Available The development of ultra-wideband (UWB communications is impeded by the drastic transmitted power limitations imposed by regulation authorities due to the “polluting” character of these radio emissions with respect to existing services. Technical solutions must be researched in order either to limit the level of spectral pollution by UWB devices or to increase their reception sensitivity. In the present work, we consider pulse-based modulations and investigate time-domain multiple-input multiple-output (MIMO diversity as one such possible solution. The basic principles of time-domain diversity in the extreme (low multipath density or intermediate (dense multipath UWB regimes are addressed, which predict the possibility of a MIMO gain equal to the product Nt×Nr of the numbers of transmit/receive antenna elements when the channel is not too severe. This analysis is confirmed by simulations using a parametric empirical stochastic double-directional channel model. They confirm the potential interest of MIMO approaches solutions in order to bring a valuable performance gain in UWB communications.

  15. Unrecorded wideband instrumentation reference tape feasibility study: Frequency response results

    Science.gov (United States)

    Hust, D. R.

    1980-03-01

    An investigation was conducted to determine signal response variations when a variety of wideband instrumentation magnetic tapes is used on a cross section of recorder/reproducer systems. Data for the investigation were collected by transmitting a set of eight sample test tapes to participating data recording/reproducing facilities for the purpose of making data measurements. Data collected represent measurements made with 16 different recorder/reproducer systems at 11 different testing facilities located throughout the United States. The data-collection process involved approximately 2 years of testing. The originating/coordinating facility was the Pacific Missile Test Center, Point Mugu, California. The test results indicated the following: all of the sample test tapes exhibited bidirectional performance within the limits of measurement repeatability; overall system stability was better in the low-band regions than in the upper-band regions; and the overall relative frequency response of the sample test tapes did not change appreciably during the 2 year investigative period. The most significant result of the test measurements is that at least 90% of the frequency response values were within + or - 2.0 dB at all frequencies. Machine stability factors such as azimuth, equalizer, and gain changes had more effect on data variability than did magnetic tape or tape speed. The use of a reference tape system is recommended as a method to assure that relative frequency response variations will be less than or equal to + or - 2.0 dB.

  16. Optimization of Planar Monopole Wideband Antenna for Wireless Communication System.

    Science.gov (United States)

    Shakib, Mohammed Nazmus; Moghavvemi, Mahmoud; Mahadi, Wan Nor Liza

    2016-01-01

    In this paper, a new compact wideband monopole antenna is presented for wireless communication applications. This antenna comprises of a new radiating patch, a new arc-shaped strip, microstrip feed line, and a notched ground plane. The proposed radiating patch is combined with a rectangular and semi-circular patch and is integrated with a partial ground plane to provide a wide impedance bandwidth. The new arc-shaped strip between the radiating patch and microstrip feed line creates an extra surface on the patch, which helps further widen the bandwidth. Inserting one step notch on the ground plane further enhances the bandwidth. The antenna has a compact size of 16×20×1.6mm3. The measured result indicated that the antenna achieves a 127% bandwidth at VSWR≤2, ranging from 4.9GHz to 22.1GHz. Stable radiation patterns with acceptable gain are achieved. Also, a measured bandwidth of 107.7% at VSWR≤1.5 (5.1-17GHz) is obtained, which is suitable for UWB outdoor propagation. This antenna is compatible with a good number of wireless standards, including UWB band, Wimax 5.4 GHz band, MVDDS (12.2-12.7GHz), and close range radar and satellite communication in the X-band (8-12GHz), and Ku band (12-18GHz).

  17. A Wideband Channel Model for Intravehicular Nomadic Systems

    Directory of Open Access Journals (Sweden)

    François Bellens

    2011-01-01

    Full Text Available The increase in electronic entertainment equipments within vehicles has rendered the idea of replacing the wired links with intra-vehicle personal area networks. Ultra-wideband (UWB seems an appropriate candidate technology to meet the required data rates for interconnecting such devices. In particular, the multiband OFDM (MB-OFDM is able to provide very high transfer rates (up to 480 MBps over relatively short distances and low transmit power. In order to evaluate the performances of UWB systems within vehicles, a reliable channel model is needed. In this paper, a nomadic system where a base station placed in the center of the dashboard wants to communicate with fixed devices placed at the rear seat is investigated. A single-input single-output (SISO channel model for intra-vehicular communication (IVC systems is proposed, based on reverberation chamber theory. The model is based on measurements conducted in real traffic conditions, with a varying number of passengers in the car. Temporal variations of the wireless channels are also characterized and parametrized. The proposed model is validated by comparing model-independent statistics with the measurements.

  18. Conceptual design of combined visible - Xray Wide-Band telescope

    Science.gov (United States)

    Takizawa, Yoshiyuki; Ebisuzaki, Toshikazu; Otani, Chico; Shimizu, Hirohiko M.; Takahashi, Yoshiyuki

    2002-12-01

    Superconduting tunnel junctions (STJ) have been developed to detect X-ray ~ visivle photons for application to astrophysics, particle physics, material physics, and so on. STJ are applicable as photon detectors with good energy resolution and a high photon-counting rate. STJ also have good efficiency because of their high absorption efficiency below 1 keV photon energy. That is advantageous in the observation of the faint objects with which the photon number is limited like astronomical objects and planetary plasma observation. STJ have potentials to open new windows of telescope. On the other hand, the progress of multilayers makes it possible to fabricated a normal incidence telescope (NIT) with high angular resolution and wide field of view up to 500 eV photon energyThe combination of the improved optical elements (multilayer) and STJ will enable us to design a new optical system in the near future. We demonstrate the design combined Visible - X-ray Wide-Band Space Telescope (WBST).

  19. Compressive Wideband Spectrum Sensing for Fixed Frequency Spectrum Allocation

    CERN Document Server

    Liu, Yipeng

    2010-01-01

    Too high sampling rate is the bottleneck to wideband spectrum sensing for cognitive radio (CR). As the survey shows that the sensed signal has a sparse representation in frequency domain in the mass, compressed sensing (CS) can be used to transfer the sampling burden to the digital signal processor. An analog to information converter (AIC) can randomly sample the received signal with sub-Nyquist rate to obtained the random measurements. Considering that the static frequency spectrum allocation of primary radios means the bounds between different primary radios is known in advance, here we incorporate information of the spectrum boundaries between different primary user as a priori information to obtain a mixed l2/l1 norm denoising operator (MNDO). In the MNDO, the estimated power spectrum density (PSD) vector is divided into block sections with bounds corresponding different allocated primary radios. Different from previous standard l1-norm constraint on the whole PSD vector, a sum of the l2 norm of each sect...

  20. PERFORMANCE OPTIMIZATION OF COGNITIVE RADIO WITH WIDEBAND SPECTRUM SENSING

    Directory of Open Access Journals (Sweden)

    E. Saraniya

    2014-09-01

    Full Text Available Cognitive radio (CR technology allows the unlicensed user to access the licensed spectrum bands. Spectrum sensing is an essential function in cognitive radio to detect the spectrum holes and opportunistically use the underutilized frequency bands without causing interference to primary user (PU. In this paper we are maximizing the throughput capacity of cognitive radio user and hence the performance of spectrum sensing and protection to licensed user improves over a wideband spectrum sensing band. The simulation of cognitive radio is done by analyzing the performance of energy detector spectrum sensing technique to detect primary user and to formulate the optimization using multiband joint detection method (MJD to achieve suitable trade- off between secondary user access and primary user network. The main aim of this paper is to maximize the probability of detection and to decrease the probabilities of miss detection and false alarm. To maximize the throughput it requires minimizing the throughput loss caused by miss detection and the significant reduction in probability of false alarm helps in achieving the spectral efficiency from the secondary user’s perspective. The simulation results show that the performance increases with the MJD method.

  1. Wideband impedance spectrum analyzer for process automation applications

    Science.gov (United States)

    Doerner, Steffen; Schneider, Thomas; Hauptmann, Peter R.

    2007-10-01

    For decades impedance spectroscopy is used in technical laboratories and research departments to investigate effects or material characteristics that affect the impedance spectrum of the sensor. Establishing this analytical approach for process automation and stand-alone applications will deliver additional and valuable information beside traditional measurement techniques such as the measurement of temperature, flow rate, and conductivity, among others. As yet, most of the current impedance analysis methods are suited for laboratory applications only since they involve stand-alone network analyzers that are slow, expensive, large, or immobile. Furthermore, those systems offer a large range of functionality that is not being used in process control and other fields of application. We developed a sensor interface based on high speed direct digital signal processing offering wideband impedance spectrum analysis with high resolution for frequency adjustment, excellent noise rejection, very high measurement rate, and convenient data exchange to common interfaces. The electronics has been implemented on two small circuit boards and it is well suited for process control applications such as monitoring phase transitions, characterization of fluidal systems, and control of biological processes. The impedance spectrum analyzer can be customized easily for different measurement applications by adapting the appropriate sensor module. It has been tested for industrial applications, e.g., dielectric spectroscopy and high temperature gas analysis.

  2. Cross-layer optimization in ultra wideband networks

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Ultra wideband (UWB) network brings both chance and challenge to personal area wireless communications. Compared with other IEEE 802 small range wireless protocols (such as WLAN and Bluetooth), UWB has both extremely high bandwidth (up to 480 Mbps) and low radiation. Moreover, the structured MAC layer of UWB is the fundamental difference to WLAN. The top one is that only when two UWB devices belong to the same piconet can they communicate with each other directly, which means that we must jointly consider topology formation and routing when deploying UWB networks because the interaction between routing and topology formation makes separate optimization ineffective. This paper tries to optimize UWB network from a cross-layer point of view. Specifically, given device spatial distribution and traffic requirement, we want to form piconets and determine routing jointly, to maximize the overall throughput. We formulate the problem of joint optimization to mixed-integer programming and give a practical lower bound that is very close to the theoretical upper bound in our simulation. Furthermore, our lower bound is much better than an algorithm that only considers topology formation in UWB networks.

  3. Compressed Measurements Based Spectrum Sensing for Wideband Cognitive Radio Systems

    Directory of Open Access Journals (Sweden)

    Taha A. Khalaf

    2015-01-01

    Full Text Available Spectrum sensing is the most important component in the cognitive radio (CR technology. Spectrum sensing has considerable technical challenges, especially in wideband systems where higher sampling rates are required which increases the complexity and the power consumption of the hardware circuits. Compressive sensing (CS is successfully deployed to solve this problem. Although CS solves the higher sampling rate problem, it does not reduce complexity to a large extent. Spectrum sensing via CS technique is performed in three steps: sensing compressed measurements, reconstructing the Nyquist rate signal, and performing spectrum sensing on the reconstructed signal. Compressed detectors perform spectrum sensing from the compressed measurements skipping the reconstruction step which is the most complex step in CS. In this paper, we propose a novel compressed detector using energy detection technique on compressed measurements sensed by the discrete cosine transform (DCT matrix. The proposed algorithm not only reduces the computational complexity but also provides a better performance than the traditional energy detector and the traditional compressed detector in terms of the receiver operating characteristics. We also derive closed form expressions for the false alarm and detection probabilities. Numerical results show that the analytical expressions coincide with the exact probabilities obtained from simulations.

  4. A novel auto-reference ultra-wideband receiver scheme

    Institute of Scientific and Technical Information of China (English)

    LIAO Xuewen; ZHU Shihua; ZENG Erlin

    2007-01-01

    A new auto-reference (AR) transmit-receive scheme and a corresponding group decision algorithm on the generaiized likelihood ratio testing(GLRT)principle is proposed in this paper to overcome the drawbacks of the power inefficiency and the high noise vulnerability in transmitted-reference(TR)ultra-wideband(UWB)systems.A partly overlapped detection window structure is introduced in which the decided data frames are regarded as the reference signal so that energy and time resources in the reference frame are saved and full-rate data transmission is achieved.Differential coding was utilized to solve the error propagation problem introduced by the overlapped detection windows.The group decision algorithm on the GLRT principle was utilized to estimate the correlation template through all data frames in detection windows and could offer better noise suppression.Simulation results reveal that the AR scheme with its decision algorithm outperforms the conventional and other modified TR schemes in generalized signal-to-noise ratio(SNR).

  5. Wideband energy harvesting based on mixed connection of piezoelectric oscillators

    Science.gov (United States)

    Wu, P. H.; Chen, Y. J.; Li, B. Y.; Shu, Y. C.

    2017-09-01

    An approach for wideband energy harvesting together with power enhancement is proposed by integrating multiple piezoelectric oscillators with mixed parallel-series connection. This gives rise to the feasibility of shifting the operation frequency band to the dominant frequency domain of ambient excitations. There are two types of connection patterns discussed here: the p-type (s-type) is the parallel (series) connection of all sets of oscillators where some of them may be connected in series (parallel). In addition, the standard interface circuit used for electric rectification is adopted here. The analytic estimates of output power are derived and explicitly expressed in terms of different matrix formulations for these two connection patterns. They are subsequently validated and are found in good agreement with numerical simulations and experimental observations. Finally, the experimental results from the mixed connection of 4 piezoelectric oscillators show that the peak power of each array is about 3.4 times higher than that generated by a single piezoelectric oscillator. In addition, the bandwidth of the array capable of switching connection patterns is around 2.8 times wider than that based on a single array configuration. Hence, the effective bandwidth is enlarged without the loss of peak power.

  6. A survey of antennas for ultra-wideband applications

    Science.gov (United States)

    Sarfaraz, Maysam; Shirkhodaie, Amir

    2008-04-01

    The usage of ultra-wideband (UWB) technology is growing in many communication systems such as radar systems, communication and measurement systems and imaging systems mainly because unlike the other wireless technologies UWB is not restricted to using a narrow waveband and it has high speed data rate. The large transmission bandwidth makes UWB-based electronic device resistive to interferences and gives immunity against getting detected. Typical operational frequency range of the UWB devices varies from few 100s MHz to 10 GHz. However, the most popular UWB devices are designed to operate between 1-3 GHz. This paper presents an overview of different types of commercially available antennas suitable for UWB applications. The paper begins with the basics of understanding of antennas properties. Next, it discusses the main antenna characteristics like: radiation pattern (directional or omni-directional), gain, bandwidth, size, etc for different UWB applications and explains criterions for quantitative and qualitative performance measure of the antennas. The antennas covered in this paper include: TEM Horn, Folded horn, Dipole, Planner Fat Dipole, Cross Dipole, Rolled Dipole, UWB dielectric, Bowtie, Wire Bowtie, etc. This paper describes the pros and cons of each antenna and highlights the application areas of each antenna. Lastly, this paper summaries the important characteristics of the antennas and presents several promising directions for future enhancement of UWB antenna systems.

  7. Predicting the intelligibility of vocoded and wideband Mandarin Chinese.

    Science.gov (United States)

    Chen, Fei; Loizou, Philipos C

    2011-05-01

    Due to the limited number of cochlear implantees speaking Mandarin Chinese, it is extremely difficult to evaluate new speech coding algorithms designed for tonal languages. Access to an intelligibility index that could reliably predict the intelligibility of vocoded (and non-vocoded) Mandarin Chinese is a viable solution to address this challenge. The speech-transmission index (STI) and coherence-based intelligibility measures, among others, have been examined extensively for predicting the intelligibility of English speech but have not been evaluated for vocoded or wideband (non-vocoded) Mandarin speech despite the perceptual differences between the two languages. The results indicated that the coherence-based measures seem to be influenced by the characteristics of the spoken language. The highest correlation (r = 0.91-0.97) was obtained in Mandarin Chinese with a weighted coherence measure that included primarily information from high-intensity voiced segments (e.g., vowels) containing F0 information, known to be important for lexical tone recognition. In contrast, in English, highest correlation was obtained with a coherence measure that included information from weak consonants and vowel/consonant transitions. A band-importance function was proposed that captured information about the amplitude envelope contour. A higher modulation rate (100 Hz) was found necessary for the STI-based measures for maximum correlation (r = 0.94-0.96) with vocoded Mandarin and English recognition.

  8. Wideband Array Signal Detection Algorithm Based on Power Focusing

    Directory of Open Access Journals (Sweden)

    Gong Bin

    2012-09-01

    Full Text Available Aiming at the requirement of real-time signal detection in the passive surveillance system, a wideband array signal detection algorithm is proposed based on the concept of power focusing. By making use of the phase difference of the signal received by a uniform linear array, the algorithm makes the power of the received signal focused in the Direction Of Arrival (DOA with improved cascade FFT. Subsequently, the probability density function of the output noise at each angle is derived. Furthermore, a Constant False Alarm Rate (CFAR test statistic and the corresponding detection threshold are constructed. The theoretical probability of detection is also derived for different false alarm rate and Signal-to-Noise Ratio (SNR. The proposed algorithm is computationally efficient, and the detection process is independent of the prior information. Meanwhile, the results can act as the initial value for other algorithms with higher precision. Simulation results show that the proposed algorithm achieves good performance for weak signal detection.

  9. Interference Mitigation for Coexistence of Heterogeneous Ultra-Wideband Systems

    Directory of Open Access Journals (Sweden)

    Wu Haitao

    2006-01-01

    Full Text Available Two ultra-wideband (UWB specifications, that is, direct-sequence (DS UWB and multiband-orthogonal frequency division multiplexing (MB-OFDM UWB, have been proposed as the candidates of the IEEE 802.15.3a, competing for the standard of high-speed wireless personal area networks (WPAN. Due to the withdrawal of the standardization process, the two heterogeneous UWB technologies will coexist in the future commercial market. In this paper, we investigate the mutual interference of such coexistence scenarios by physical layer Monte Carlo simulations. The results reveal that the coexistence severely degrades the performance of both UWB systems. Moreover, such interference is asymmetric due to the heterogeneity of the two systems. Therefore, we propose the goodput-oriented utility-based transmit power control (GUTPC algorithm for interference mitigation. The feasible condition and the convergence property of GUTPC are investigated, and the choice of the coefficients is discussed for fairness and efficiency. Numerical results demonstrate that GUTPC improves the goodput of the coexisting systems effectively and fairly with saved power.

  10. High-resolution wide-band Fast Fourier Transform spectrometers

    CERN Document Server

    Klein, Bernd; Krämer, Ingo; Bell, Andreas; Meyer, Klaus; Güsten, Rolf

    2012-01-01

    We describe the performance of our latest generations of sensitive wide-band high-resolution digital Fast Fourier Transform Spectrometer (FFTS). Their design, optimized for a wide range of radio astronomical applications, is presented. Developed for operation with the GREAT far infrared heterodyne spectrometer on-board SOFIA, the eXtended bandwidth FFTS (XFFTS) offers a high instantaneous bandwidth of 2.5 GHz with 88.5 kHz spectral resolution and has been in routine operation during SOFIA's Basic Science since July 2011. We discuss the advanced field programmable gate array (FPGA) signal processing pipeline, with an optimized multi-tap polyphase filter bank algorithm that provides a nearly loss-less time-to-frequency data conversion with significantly reduced frequency scallop and fast sidelobe fall-off. Our digital spectrometers have been proven to be extremely reliable and robust, even under the harsh environmental conditions of an airborne observatory, with Allan-variance stability times of several 1000 se...

  11. Ultra-Wideband Printed Slot Radiators with Controllable Frequency Characteristics

    Directory of Open Access Journals (Sweden)

    S. L. Chernyshev

    2015-01-01

    Full Text Available We have studied the possibility of creating ultra-wideband (UWB antennas with controlled frequency response of matching based on the printed slot antenna Vivaldi by introducing controlled resonators directly into the structure of the radiator. In the area of irregular slotline there are printed switched resonators with variable capacitance (varactor model, which allow tuning the frequency characteristics for each state of switching cavities, providing bandpass and band-barrage properties of the antenna. The investigation of reconfigurable printed resonators in the system of reconfigurable resonators of a bandpass filter is conducted. The paper considers filter to provide restructuring in the band (3-9 GHz. Electrodynamic simulation of the device was carried out in the time domain using a finite integration method. A bandstop reconfigurable filter is also investigated. The filter located on the substrate opposite the slit is based on tunable L-shaped resonator that has one end connected to the short-circuitor through the board metallization; the other end remains open and is brought into the region of interaction with the slotline. Such filter provides an effective narrow-band suppression and can be easily tuned to the desired frequency channel. The combination of these two types of filters allows you to create a controlled print Vivaldi slot antenna with combined properties. The paper investigates parameters of the scattering and radiation pattern of the antenna in different modes.

  12. Ultra-wideband spectral analysis using S2 technology

    Energy Technology Data Exchange (ETDEWEB)

    Krishna Mohan, R. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States)]. E-mail: krishna@spectrum.montana.edu; Chang, T. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Tian, M. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Bekker, S. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Olson, A. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Ostrander, C. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Khallaayoun, A. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Dollinger, C. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Babbitt, W.R. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Cole, Z. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); S2 Corporation, Bozeman, MT 59718 (United States); Reibel, R.R. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); S2 Corporation, Bozeman, MT 59718 (United States); Merkel, K.D. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); S2 Corporation, Bozeman, MT 59718 (United States); Sun, Y. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Cone, R. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Schlottau, F. [University of Colorado, Boulder, CO 80309 (United States); Wagner, K.H. [University of Colorado, Boulder, CO 80309 (United States)

    2007-11-15

    This paper outlines the efforts to develop an ultra-wideband spectrum analyzer that takes advantage of the broad spectral response and fine spectral resolution ({approx}25 kHz) of spatial-spectral (S2) materials. The S2 material can process the full spectrum of broadband microwave transmissions, with adjustable time apertures (down to 100 {mu}s) and fast update rates (up to 1 kHz). A cryogenically cooled Tm:YAG crystal that operates on microwave signals modulated onto a stabilized optical carrier at 793 nm is used as the core for the spectrum analyzer. Efforts to develop novel component technologies that enhance the performance of the system and meet the application requirements are discussed, including an end-to-end device model for parameter optimization. We discuss the characterization of new ultra-wide bandwidth S2 materials. Detection and post-processing module development including the implementation of a novel spectral recovery algorithm using field programmable gate array technology (FPGA) is also discussed.

  13. Multihop Diversity in Wideband OFDM Systems: The Impact of Spatial Reuse and Frequency Selectivity

    CERN Document Server

    Oyman, Ozgur

    2008-01-01

    The goal of this paper is to establish which practical routing schemes for wireless networks are most suitable for wideband systems in the power-limited regime, which is, for example, a practically relevant mode of operation for the analysis of ultrawideband (UWB) mesh networks. For this purpose, we study the tradeoff between energy efficiency and spectral efficiency (known as the power-bandwidth tradeoff) in a wideband linear multihop network in which transmissions employ orthogonal frequency-division multiplexing (OFDM) modulation and are affected by quasi-static, frequency-selective fading. Considering open-loop (fixed-rate) and closed-loop (rate-adaptive) multihop relaying techniques, we characterize the impact of routing with spatial reuse on the statistical properties of the end-to-end conditional mutual information (conditioned on the specific values of the channel fading parameters and therefore treated as a random variable) and on the energy and spectral efficiency measures of the wideband regime. Ou...

  14. 8th conference on Ultra-Wideband Short-Pulse Electromagnetics

    CERN Document Server

    Tyo, J. Scott; Baum, Carl E; Ultra-Wideband Short-Pulse Electromagnetics 8; UWBSP8

    2007-01-01

    The purpose of the Ultra-Wideband Short-Pulse Electromagnetics Conference series is to focus on advanced technologies for the generation, radiation and detection of ultra-wideband short pulse signals, taking into account their propagation and scattering from and coupling to targets of interest. This Conference series reports on developments in supporting mathematical and numerical methods and presents current and potential future applications of the technology. Ultra-Wideband Short-Pulse Electromagnetics 8 is based on the American Electromagnetics 2006 conference held from June 3-7 in Albuquerque, New Mexico. Topical areas covered in this volume include pulse radiation and measurement, scattering theory, target detection and identification, antennas, signal processing, and communications.

  15. Total Variation Minimization Based Compressive Wideband Spectrum Sensing for Cognitive Radios

    CERN Document Server

    Liu, Yipeng

    2011-01-01

    Wideband spectrum sensing is a critical component of a functioning cognitive radio system. Its major challenge is the too high sampling rate requirement. Compressive sensing (CS) promises to be able to deal with it. Nearly all the current CS based compressive wideband spectrum sensing methods exploit only the frequency sparsity to perform. Motivated by the achievement of a fast and robust detection of the wideband spectrum change, total variation mnimization is incorporated to exploit the temporal and frequency structure information to enhance the sparse level. As a sparser vector is obtained, the spectrum sensing period would be shorten and sensing accuracy would be enhanced. Both theoretical evaluation and numerical experiments can demonstrate the performance improvement.

  16. Wideband Circularly Polarized SIW Antenna Array That Uses Sequential Rotation Feeding

    Directory of Open Access Journals (Sweden)

    Fang-Fang Fan

    2014-01-01

    Full Text Available A wideband right-handed circularly polarized (CP substrate integrated waveguide- (SIW- based diamond ring-slot antenna array at the X-band is presented in this study. The array consists of four elements that exhibit wideband impedance matching characteristics and good radiation performance. The array also employs a sequential rotation feeding method to achieve the wideband axial ratio (AR bandwidth. The feeding network is based on the SIW power divider with a delay line related to sequential rotation feeding. To validate our design, an antenna array is fabricated and measured. The measured impedance and AR bandwidths are 19.2% (VSWR<2 and 14.1% (AR<3 dB, respectively. Moreover, the antenna has a stable CP peak gain of more than 12 dBic from 10.1 GHz to 10.7 GHz.

  17. Mutual Coupling Reduction for UWB MIMO Antennas with a Wideband Neutralization Line

    DEFF Research Database (Denmark)

    Zhang, Shuai; Pedersen, Gert F.

    2016-01-01

    A wideband neutralization line is proposed to reduce the mutual coupling of a compact ultrawideband (UWB) MIMO antenna. With the introduced decoupling method, the designed UWB MIMO antenna covers the band of 3.1-5 GHz with an isolation of higher than 22 dB. The proposed wideband neutralization line...... is not necessarily placed in the clearance area between two MIMO elements and can be put above the copper ground. A small clearance (antenna area) of 35 mm × 16 mm is achieved. The designed UWB MIMO antenna is fabricated. S parameters, radiation patterns, total efficiency and realized gain of the prototype...

  18. Wideband Radar Echo Frequency-domain Simulation and Analysis for High Speed Moving Targets

    Directory of Open Access Journals (Sweden)

    Ning Chao

    2014-04-01

    Full Text Available A frequency-domain method is proposed for wideband radar echo simulation of high-speed moving targets. Based on the physical process of electromagnetic waves observing a moving target, a frequency-domain echo model of wideband radar is constructed, and the block diagram of the radar echo simulation in frequency-domain is presented. Then, the impacts of radial velocity and slant range on the matching filtering of LFM radar are analyzed, and some quantitative conclusions on the shift and expansion of the radar profiles are obtained. Simulation results illustrate the correctness and efficiency of the proposed method.

  19. Ultra-Wideband Fermi Antenna Using Microstrip-to-CPS Balun

    Science.gov (United States)

    Woo, Dong-Sik; Kim, Young-Gon; Cho, Young-Ki; Kim, Kang Wook

    A new design and experimental results of a microstrip-fed ultra-wideband Fermi antenna at millimeter-wave frequencies are presented. By utilizing a new microstrip-to-CPS balun (or transition), which provides wider bandwidth than conventional planar balun, the design of microstrip-fed Fermi antenna is greatly simplified. The proposed Fermi antenna demonstrates ultra-wideband performance for the frequency range of 23 to over 58GHz with the antenna gain of 12 to 14dBi and low sidelobe levels. This design yields highly effective solutions to various millimeter-wave phased-arrays and imaging systems.

  20. Design and Implementation of Wideband Exciter for an Ultra-high Resolution Airborne SAR System

    Directory of Open Access Journals (Sweden)

    Jia Ying-xin

    2013-03-01

    Full Text Available According to an ultra-high resolution airborne SAR system with better than 0.1 m resolution, a wideband Linear Frequency Modulated (LFM pulse compression exciter with 14.8 GHz carrier and 3.2 GHz bandwidth is designed and implemented. The selection of signal generation scheme and some key technique points for wideband LFM waveform is presented in detail. Then, an acute test and analysis of the LFM signal is performed. The final airborne experiments demonstrate the validity of the LFM source which is one of the subsystems in an ultra-high resolution airborne SAR system.

  1. Wideband multiwavelength erbium-doped fiber ring laser with frequency shifted feedback

    Science.gov (United States)

    Kim, Seung Kwan; Chu, Moo Jung; Lee, Jong Hyun

    2001-04-01

    Wideband multiwavelength erbium-doped fiber ring lasers with frequency shifted feedback are described. The use of an intra-cavity gain flattening filter (GFF) was proposed in order to increase the lasing spectral bandwidth, leading to a demonstration of 34 lasing wavelengths in 28 nm bandwidth in C-band. The GFF induced spectral output power fluctuation is discussed. Multiwavelength operation was also demonstrated for the first time in L-band, where wideband laser operation was obtained without a GFF. Optical bistability and Kerr effect induced pulsation were determined to be limiting factors to stable operation range in this kind of multiwavelength lasers.

  2. Analysis and Design of Wide-Band SiGe HBT Active Mixers

    DEFF Research Database (Denmark)

    Johansen, Tom Keinicke; Krozer, Viktor; Vidkjær, Jens

    2005-01-01

    performing frequency conversion of wide-band signals is discussed. The analysis is verified by computer simulations using a realistic high-frequency large-signal SiGe HBT model. An active mixer design based on the Gilbert cell topology modified for wide-band operation using emitter degenerated...... transconductance stage and shunt feedback load stage is discussed. Experimental results are given for an active mixer implemented in a 0.8-μm 35-GHz fT SiGe HBT BiCMOS process....

  3. Novel wideband MIMO antennas that can cover the whole LTE spectrum in handsets and portable computers.

    Science.gov (United States)

    Sanad, Mohamed; Hassan, Noha

    2014-01-01

    A dual resonant antenna configuration is developed for multistandard multifunction mobile handsets and portable computers. Only two wideband resonant antennas can cover most of the LTE spectrums in portable communication equipment. The bandwidth that can be covered by each antenna exceeds 70% without using any matching or tuning circuits, with efficiencies that reach 80%. Thus, a dual configuration of them is capable of covering up to 39 LTE (4G) bands besides the existing 2G and 3G bands. 2×2 MIMO configurations have been also developed for the two wideband antennas with a maximum isolation and a minimum correlation coefficient between the primary and the diversity antennas.

  4. Genetic algorithm-based wide-band deterministic maximum likelihood direction finding algorithm

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The wide-band direction finding is one of hit and difficult task in array signal processing. This paper generalizes narrow-band deterministic maximum likelihood direction finding algorithm to the wideband case, and so constructions an object function, then utilizes genetic algorithm for nonlinear global optimization. Direction of arrival is estimated without preprocessing of array data and so the algorithm eliminates the effect of pre-estimate on the final estimation. The algorithm is applied on uniform linear array and extensive simulation results prove the efficacy of the algorithm. In the process of simulation, we obtain the relation between estimation error and parameters of genetic algorithm.

  5. A novel algorithm of channel resource allocation in wide-band WLAN

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    With the development of Wide-band wireless communications.MAC protocol in IEEE 802.11 call't satisfy user-individual quality of service(QoS)guarantees effectively and can't support hish-speed mobility.A novel algorithm for channel allocation in Wide-band WLAN and an improved resource reservation mechanism aDplied into IEEE 802.11 MAC protocol are proposed in this article.The simulated results indicate that the advanced protocol makes the system throughput improved and delay decrease.Moreover,the improved system shows an excellent performance in the environment with high-speed mobility.

  6. Compact Wideband and Low-Profile Antenna Mountable on Large Metallic Surfaces

    DEFF Research Database (Denmark)

    Zhang, Shuai; Pedersen, Gert F.

    2017-01-01

    This paper proposes a compact wideband and low-profile antenna mountable on large metallic surfaces. Six rows of coupled microstrip resonators with different lengths are printed on a Teflon block. The lengths of the microstrip resonators in different rows are gradually reduced along the end...... resonance at the lowest frequency. A trapezoid-shaped capacitive-feed (C-fed) strip is utilized and also printed on the Teflon block to globally optimize the wideband impedance matching. The proposed antenna covers a relative bandwidth of 109% for VSWR

  7. Wide-band profile domain pulsar timing analysis

    Science.gov (United States)

    Lentati, L.; Kerr, M.; Dai, S.; Hobson, M. P.; Shannon, R. M.; Hobbs, G.; Bailes, M.; Bhat, N. D. Ramesh; Burke-Spolaor, S.; Coles, W.; Dempsey, J.; Lasky, P. D.; Levin, Y.; Manchester, R. N.; Osłowski, S.; Ravi, V.; Reardon, D. J.; Rosado, P. A.; Spiewak, R.; van Straten, W.; Toomey, L.; Wang, J.; Wen, L.; You, X.; Zhu, X.

    2017-04-01

    We extend profile domain pulsar timing to incorporate wide-band effects such as frequency-dependent profile evolution and broad-band shape variation in the pulse profile. We also incorporate models for temporal variations in both pulse width and in the separation in phase of the main pulse and interpulse. We perform the analysis with both nested sampling and Hamiltonian Monte Carlo methods. In the latter case, we introduce a new parametrization of the posterior that is extremely efficient in the low signal-to-noise regime and can be readily applied to a wide range of scientific problems. We apply this methodology to a series of simulations, and to between seven and nine years of observations for PSRs J1713+0747, J1744-1134 and J1909-3744 with frequency coverage that spans 700-3600 Mhz. We use a smooth model for profile evolution across the full frequency range, and compare smooth and piecewise models for the temporal variations in dispersion measure (DM). We find that the profile domain framework consistently results in improved timing precision compared to the standard analysis paradigm by as much as 40 per cent for timing parameters. Incorporating smoothness in the DM variations into the model further improves timing precision by as much as 30 per cent. For PSR J1713+0747, we also detect pulse shape variation uncorrelated between epochs, which we attribute to variation intrinsic to the pulsar at a level consistent with previously published analyses. Not accounting for this shape variation biases the measured arrival times at the level of ∼30 ns, the same order of magnitude as the expected shift due to gravitational waves in the pulsar timing band.

  8. Ultra-Wideband Optical Modulation Spectrometer (OMS) Development

    Science.gov (United States)

    Gardner, Jonathan (Technical Monitor); Tolls, Volker

    2004-01-01

    The optical modulation spectrometer (OMS) is a novel, highly efficient, low mass backend for heterodyne receiver systems. Current and future heterodyne receiver systems operating at frequencies up to a few THz require broadband spectrometer backends to achieve spectral resolutions of R approximately 10(exp 5) to 10(exp 6) to carry out many important astronomical investigations. Among these are observations of broad emission and absorption lines from extra-galactic objects at high redshifts, spectral line surveys, and observations of planetary atmospheres. Many of these lines are pressure or velocity broadened with either large half-widths or line wings extending over several GHz. Current backend systems can cover the needed bandwidth only by combining the output of several spectrometers, each with typically up to 1 GHz bandwidth, or by combining several frequency-shifted spectra taken with a single spectrometer. An ultra-wideband optical modulation spectrometer with 10 - 40 GHz bandwidth will enable broadband ob- servations without the limitations and disadvantages of hybrid spectrometers. Spectrometers like the OMS will be important for both ground-based observatories and future space missions like the Single Aperture Far-Infrared Telescope (SAFIR) which might carry IR/submm array heterodyne receiver systems requiring a spectrometer for each array pixel. Small size, low mass and small power consumption are extremely important for space missions. This report summarizes the specifications developed for the OMS and lists already identified commercial parts. The report starts with a review of the principle of operation, then describes the most important components and their specifications which were derived from theory, and finishes with a conclusion and outlook.

  9. Super-resolved time-frequency analysis of wideband backscattered data

    DEFF Research Database (Denmark)

    Moore, John; Ling, H.

    1995-01-01

    A time-frequency super-resolution procedure is presented for processing wideband backscattered data containing both scattering center and natural resonance information. In this procedure, Prony's method is first applied in the frequency domain to locate scattering centers. The data is processed one...

  10. Modeling alien-line impedance mismatch in wideband vectored wireline systems

    NARCIS (Netherlands)

    Medeiros, E.; Magesacher, T.; Ödling, P.; Wei, D.; Wang, X.; Li, Q.; Eriksson, P.E.; Lu, C.; Boschma, J.J.; Heuvel, B.M. van den

    2014-01-01

    Sudden changes of channel coefficients in a wideband vectored wireline system (such as G.fast) due to changes in the terminating impedance of lines outside the vectored group can seriously degrade stability and throughput. This letter presents a model that predicts the impact of termination mismatch

  11. Wideband CMOS receivers exploiting simultaneous output balancing and noise/distortion canceling

    NARCIS (Netherlands)

    Blaakmeer, S.C.; Klumperink, Eric A.M.; Leenaerts, D.M.W.; Nauta, Bram

    2008-01-01

    Abstract— This paper deals with the problem of realizing wideband receiver front-ends in downscaled CMOSTechnologies, which are highly wanted for multi-standard radio receivers and cognitive radio applications. Instead of using many narrowband inductor based receivers, we prefer the use of one

  12. Ground Penetrating Radar: Ultra-wideband radars for improvised explosive devices and landmine detection

    NARCIS (Netherlands)

    Yarovoy, A.

    2008-01-01

    For last two decades Ultra-Wideband Ground Penetrating Radars seemed to be a useful tool for detection and classification of landmines and improvised explosive devices (IEDs). However limitations of radar technology considerably limited operational use of these radars. Recent research at TU Delft so

  13. Ground Penetrating Radar: Ultra-wideband radars for improvised explosive devices and landmine detection

    OpenAIRE

    Yarovoy, A.

    2008-01-01

    For last two decades Ultra-Wideband Ground Penetrating Radars seemed to be a useful tool for detection and classification of landmines and improvised explosive devices (IEDs). However limitations of radar technology considerably limited operational use of these radars. Recent research at TU Delft solves the bottleneck problems.

  14. First Experimental Impulse-Radio Ultra-Wideband Transmission Under the Russian Spectral Emission Mask

    DEFF Research Database (Denmark)

    Grakhova, Elizaveta P.; Rommel, Simon; Jurado-Navas, Antonio

    2016-01-01

    Ultra-wideband impulse-radio wireless transmission under the stringent conditions and complex shape of the Russian spectral emission mask is experimentally demonstrated for the first time. Transmission of 1Gbit/s and 1.25Gbit/s signals over distances of 6m and 3m is achieved with a BER below 3.8×...

  15. Wideband Erbium-Ytterbium Co-Doped Phosphate Glass Waveguide Amplifier

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new '(?)' type of wideband erbium-ytterbium co-doped phosphate glass waveguide amplifier integrated with medium thin film filter is proposed, Average gain about 15.5dB between 1530nm and 1570nm with gain difference of below 2 dB is obtained.

  16. Enhanced bit rate-distance product impulse radio ultra-wideband over fiber link

    DEFF Research Database (Denmark)

    Rodes Lopez, Roberto; Jensen, Jesper Bevensee; Caballero Jambrina, Antonio

    2010-01-01

    We report on a record distance and bit rate-wireless impulse radio (IR) ultra-wideband (UWB) link with combined transmission over a 20 km long fiber link. We are able to improve the compliance with the regulated frequency emission mask and achieve bit rate-distance products as high as 16 Gbit/s·m....

  17. Impact of Noise Power Uncertainty on the Performance of Wideband Spectrum Segmentation

    Directory of Open Access Journals (Sweden)

    S. Tascioglu

    2010-12-01

    Full Text Available The objective of this work is to investigate the impact of noise uncertainty on the performance of a wideband spectrum segmentation technique. We define metrics to quantify the degradation due to noise uncertainty and evaluate the performance using simulations. Our simulation results show that the noise uncertainty has detrimental effects especially for low SNR users.

  18. Wideband helicity dependent spoof surface plasmon polaritons coupling metasurface based on dispersion design

    Science.gov (United States)

    Dong, Guoxiang; Shi, Hongyu; He, Yuchen; Zhang, Anxue; Wei, Xiaoyong; Zhuang, Yongyong; Du, Bai; Xia, Song; Xu, Zhuo

    2016-12-01

    The surface plasmon polaritons (SPPs) have many potential application due to their local field enhancement and sub-wavelength characteristics. Recently, the gradient metasurface is introduced to couple the spoof SPPs in microwave frequency band. One of the most important issue which should be solved is the narrowband of spoof SPPs coupling on the gradient metasurface. Here, the metasurface is proposed to achieve the wideband helicity dependent directional spoof SPPs coupling for circular polarized light. Our research show that the coupling frequency of spoof SPPs on the gradient metasurface is determined by the dispersion of the metasurface, so the coupling frequency can be controlled by dispersion design. The careful design of each cell geometric parameters has provided many appropriate dispersion relations possessed by just one metasurface. The wave vector matching between the propagating wave and the spoof SPPs has been achieved at several frequencies for certain wave vector provided by the metasurface, which leads to wideband spoof SPPs coupling. This work has shown that wideband helicity dependent directional spoof SPPs coupling has been achieved with a high efficiency. Hence, the proposed wideband spoof SPPs coupling presents the improvement in practice applications.

  19. Analytical Description and Design of Printed Dipole Arrays for Wideband Wide-Scan Applications

    NARCIS (Netherlands)

    Cavallo, D.; Neto, A.; Gerini, G.

    2012-01-01

    Wideband arrays of printed dipoles with inter-element loads are investigated. A closed-form expression for the active input impedance of the array element is derived with a spectral domain approach. The procedure is based on an extension of the Green's function formulation for arrays of connected di

  20. Up to 35 Gbps Ultra-Wideband Wireless Data Transmission Links

    DEFF Research Database (Denmark)

    Puerta Ramírez, Rafael; Rommel, Simon; Vegas Olmos, Juan José

    2016-01-01

    For the first time Ultra-Wideband record data transmission rates up to 35.1 Gbps and 21.6 Gbps are achieved, compliant with the restrictions on the effective radiated power established by both the United States Federal Communications Commission and the European Electronic Communications Committee...

  1. A wide-band compact end-entry septum polariser OMT

    Science.gov (United States)

    Dang, N. D.; Kapartis, S.; Brain, D. J.

    The theoretical design and measured performance of an extremely compact wide-band end-entry septum polarizer orthomode transducer (OMT) are described. The in-line configuration is compatible with the requirements of a closely packed feed array geometry. It is noted that this OMT offers a significantly better performance than previously published empirical designs within a much shorter length.

  2. Wideband impedance measurements and modeling of DC motors for EMI predictions

    NARCIS (Netherlands)

    Diouf, F.; Leferink, Frank Bernardus Johannes; Duval, Fabrice; Bensetti, Mohamed

    2015-01-01

    In electromagnetic interference prediction, dc motors are usually modeled as a source and a series impedance. Previous researches only include the impedance of the armature, while neglecting the effect of the motor's rotation. This paper aims at measuring and modeling the wideband impedance of a dc

  3. Dual-polarization, wideband microstrip antenna array for airborne C-band SAR

    DEFF Research Database (Denmark)

    Granholm, Johan; Skou, Niels

    2000-01-01

    The paper describes the development of a C-band, dual linear polarization wideband antenna array, for use in the next-generation of the Danish airborne polarimetric synthetic aperture radar (SAR) system. The array is made of probe-fed, stacked microstrip patches. The design and performance...

  4. Binaural detection with narrowband and wideband reproducible noise maskers: II. Results for rabbit

    Science.gov (United States)

    Zheng, Ling; Early, Susan J.; Mason, Christine R.; Idrobo, Fabio; Harrison, J. Michael; Carney, Laurel H.

    2002-01-01

    Binaural detection with narrowband and wideband noise maskers was examined by using a Pavlovian-conditioned eyeblink response in rabbits. The target was a tone at 500 Hz, and the maskers were ten individual noise samples having one of two bandwidths, 200 Hz (410 Hz to 610 Hz) or 2900 Hz (100 Hz to 3 kHz). The narrowband noise maskers were created by filtering the wideband noise maskers such that the two sets of maskers had identical spectra in the 200-Hz frequency region surrounding the tone. The responses across the set of noise maskers were compared across bandwidths and across interaural configurations (N0S0 and N0Sπ). Responses across the set of noise waveforms were not strongly correlated across bandwidths; this result is inconsistent with models for binaural detection that depend only upon the narrow band of energy centered at the frequency of the target tone. Responses were correlated across interaural configurations for the wideband masker condition, but not for the narrowband masker. All of these results were consistent with the companion study of human listeners [Evilsizer et al., J. Acoust. Soc. Am. 111, 336-345 (2002)] and with the results of human studies of binaural detection that used only wideband [Gilkey et al., J. Acoust. Soc. Am. 78, 1207-1219 (1985)] or narrowband [Isabelle and Colburn, J. Acoust. Soc. Am. 89, 352-259 (1991)] individual noise maskers.

  5. Miniature wideband filter based on coupled-line sections and quasi-lumped element resonator

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Krozer, Viktor; Meincke, Peter

    2007-01-01

    A new design of a wideband bandpass filter is proposed, based on coupled-line sections and quasi-lumped element resonator, taking advantage of the last one to introduce two transmission zeros and suppress a spurious response. The proposed filter demonstrates significantly improved characteristics...

  6. A Wideband 2x13-bit All-Digital I/Q RF-DAC

    NARCIS (Netherlands)

    Alavi, S.M.; Staszewski, R.B.; De Vreede, L.C.N.; Long, J.R.

    2014-01-01

    This paper presents a wideband 2 13-bit in-phase/quadrature-phase (I/Q) RF digital-to-analog converter-based all-digital modulator realized in 65-nm CMOS. The isolation between I and Q paths is guaranteed employing 25% duty-cycle differential quadrature clocks. With a 1.3-V supply and an on-chip pow

  7. A photonic ultra-wideband pulse generator based on relaxation oscillations of a semiconductor laser

    DEFF Research Database (Denmark)

    Yu, Xianbin; Gibbon, Timothy Braidwood; Pawlik, Michal;

    2009-01-01

    A photonic ultra-wideband (UWB) pulse generator based on relaxation oscillations of a semiconductor laser is proposed and experimentally demonstrated. We numerically simulate the modulation response of a direct modulation laser (DML) and show that due to the relaxation oscillations of the laser...

  8. The Large Office Environment - Measurement and Modeling of the Wideband Radio Channel

    DEFF Research Database (Denmark)

    Andersen, Jørgen Bach; Nielsen, Jesper Ødum; Bauch, Gerhard

    2006-01-01

    In a future 4G or WLAN wideband application we can imagine multiple users in a large office environment con-sisting of a single room with partitions. Up to now, indoor radio channel measurement and modelling has mainly concentrated on scenarios with several office rooms and corridors. We present...

  9. Wide-band CMOS low-noise amplifier exploiting thermal-noise canceling

    NARCIS (Netherlands)

    Bruccoleri, Federico; Klumperink, Eric A.M.; Nauta, Bram

    2004-01-01

    Known elementary wide-band amplifiers suffer from a fundamental tradeoff between noise figure (NF) and source impedance matching, which limits the NF to values typically above 3 dB. Global negative feedback can be used to break this tradeoff, however, at the price of potential instability. In contra

  10. Conformal antenna array for ultra-wideband direction-of-arrival estimation

    NARCIS (Netherlands)

    Liberal, I.; Caratelli, D.; Yarovoy, A.

    2011-01-01

    The design and full-wave analysis of an antenna system for ultra-wideband radio direction finding applications is presented. The elliptical dipole antenna is selected as antenna element due to its robust circuital and radiation properties. The influence of the conformal deformation on the antenna

  11. Conformal antenna array for ultra-wideband direction-of-arrival estimation

    NARCIS (Netherlands)

    Liberal, I.; Caratelli, D.; Yarovoy, A.

    2011-01-01

    The design and full-wave analysis of an antenna system for ultra-wideband radio direction finding applications is presented. The elliptical dipole antenna is selected as antenna element due to its robust circuital and radiation properties. The influence of the conformal deformation on the antenna pe

  12. Design of an ultra-wideband ground-penetrating radar system using impulse radiating antennas

    NARCIS (Netherlands)

    Rhebergen, J.B.; Zwamborn, A.P.M.; Giri, D.V.

    1999-01-01

    At TNO-FEL, one of the research programs is to explore the use of ultra-wideband (UWB) electromagnetic fields in a bi-static ground-penetrating radar (GPR) system for the detection, location and identification of buried items of unexploded ordnance (e.g. land mines). In the present paper we describe

  13. Design of an ultra-wideband ground-penetrating radar system using impulse radiating antennas

    NARCIS (Netherlands)

    Rhebergen, J.B.; Zwamborn, A.P.M.; Giri, D.V.

    1998-01-01

    At TNO-FEL, one of the research programs is to explore the use of ultra-wideband (UWB) electromagnetic fields in a bi-static ground-penetrating radar (GPR) system for the detection, location and identification of buried items of unexploded ordnance (e.g. land mines). In the present paper we describe

  14. Frequency Invariant Uniform Circular Array for Wideband mm-Wave Channel Characterization

    DEFF Research Database (Denmark)

    Zhang, Fengchun; Fan, Wei; Pedersen, Gert F.

    2017-01-01

    A new approach for designing frequency invariant (FI) uniform circular array (UCA) is proposed, and its application to wideband multipath estimation at millimeter wave bands is studied. Both numerical simulations and channel sounding results at mm-Wave bands are provided to demonstrate...... the effectiveness and improvement of the proposed method in channel parameter estimation over conventional FI UCA method....

  15. Wideband impedance measurements and modeling of DC motors for EMI predictions

    NARCIS (Netherlands)

    Diouf, Fatou; Leferink, Frank; Duval, Fabrice; Bensetti, Mohamed

    2015-01-01

    In electromagnetic interference prediction, dc motors are usually modeled as a source and a series impedance. Previous researches only include the impedance of the armature, while neglecting the effect of the motor's rotation. This paper aims at measuring and modeling the wideband impedance of a dc

  16. Mitigation of wideband interference on UWB-IR transmission using multi-carrier templates

    NARCIS (Netherlands)

    Lakshmanan, M.K.; Nikookar, H.

    2009-01-01

    Ultra wideband (UWB) wireless systems are highly susceptible to interference from other services. To reduce the effect of interference from co-existing sources such as the WLAN standard IEEE 802.11a on UWB Communication, the construction of a modified template waveform using multi-carrier sinusoids

  17. Provision of 9.6-kbps wideband data rate capability in the DSN

    Science.gov (United States)

    Brunder, G. J.

    1982-01-01

    The new 9.6-kbps wideband data rate capability in the DSN is reviewed. A functional description of the completed implementation is presented, together with a plan to upgrade the central communications terminal for additional 9.6 s operational flexibility.

  18. Wide-Band Optical Fibre System for Investigation of MEMS and NEMS Deflection

    Directory of Open Access Journals (Sweden)

    Orłowska Karolina

    2014-08-01

    Full Text Available In this work the construction of experimental setup for MEMS/NEMS deflection measurements is presented. The system is based on intensity fibre optic detector for linear displacement sensing. Furthermore the electronic devices: current source for driving the light source and photodetector with wide-band preamplifier are presented.

  19. Individual Differences in Cue-Induced Motivation and Striatal Systems in Rats Susceptible to Diet-Induced Obesity

    OpenAIRE

    Robinson, Mike JF; Burghardt, Paul R.; Patterson, Christa M.; Nobile, Cameron W; Akil, Huda; Watson, Stanley J.; Berridge, Kent C.; Ferrario, Carrie R

    2015-01-01

    Pavlovian cues associated with junk-foods (caloric, highly sweet, and/or fatty foods), like the smell of brownies, can elicit craving to eat and increase the amount of food consumed. People who are more susceptible to these motivational effects of food cues may have a higher risk for becoming obese. Further, overconsumption of junk-foods leading to the development of obesity may itself heighten attraction to food cues. Here, we used a model of individual susceptibility to junk-foods diet-indu...

  20. New Wideband Beam-forming Method Used in Underwater Communication System%New Wideband Beam-forming Method Used in Underwater Communication System

    Institute of Scientific and Technical Information of China (English)

    苏为; 黄晓燕; 程恩; 袁飞; 孙海信

    2011-01-01

    A novel wideband beam-forming structure with constant beam width based on complex coefficients (FIR) digital filters used in underwater acoustic communication is proposed. First, the received signals are compensated with integer sampling period by using delay line. Then their complex envelopes are calculated by using frequency shift method. Finally, the envelopes are weighted by using complex coefficients FIR digital filters whose coefficients are optimized. Simulation re- sults show that, in the communication band, the maximum difference between the designed beam and desired beam is less than 0.3 dB when the ratio of communication band to carrier frequency is 0. 85.

  1. CW Interference Effects on High Data Rate Transmission Through the ACTS Wideband Channel

    Science.gov (United States)

    Kerczewski, Robert J.; Ngo, Duc H.; Tran, Quang K.; Tran, Diepchi T.; Yu, John; Kachmar, Brian A.; Svoboda, James S.

    1996-01-01

    Satellite communications channels are susceptible to various sources of interference. Wideband channels have a proportionally greater probability of receiving interference than narrowband channels. NASA's Advanced Communications Technology Satellite (ACTS) includes a 900 MHz bandwidth hardlimiting transponder which has provided an opportunity for the study of interference effects of wideband channels. A series of interference tests using two independent ACTS ground terminals measured the effects of continuous-wave (CW) uplink interference on the bit-error rate of a 220 Mbps digitally modulated carrier. These results indicate the susceptibility of high data rate transmissions to CW interference and are compared to results obtained with a laboratory hardware-based system simulation and a computer simulation.

  2. In-situ identification of marine organisms using high frequency, wideband ultrasound

    DEFF Research Database (Denmark)

    Pham, An Hoai

    at all frequencies in the low MHz range. The part of a fish that contributes most is not necessarily the swimbladder as the results indicate that in the low MHz frequency range bone structures, and skin surfaces are more important. The second case study was to develop a method to generate simulated...... that higher frequencies and broader bandwidths than used until now will give more information useful for fish species identification. The objective of this Ph.D. study has been to develop a method to investigate the possibility of in-situ identification of fish with high-frequency, wideband ultrasound....... The approach was to build a 1 MHz wideband single-element transducer system to obtain range profiles of fish, and to do fish species identification by comparing measured range profiles with libraries of reference range profiles as it is done in some radar systems used to identify aircraft. To do this...

  3. Wideband Tuning of Impedance Matching for actual RF Networks using AQPSO

    Directory of Open Access Journals (Sweden)

    Yin Xin

    2013-11-01

    Full Text Available An adaptive wideband impedance matching technique using a passive PI-network is presented in the paper on the basis of adaptive quantum particle swarm optimization algorithms (AQPSO, which  avoiding the drawbacks of the standard particle swarm optimization (PSO algorithm. The Wideband Tuning technique is for actual RF chips. So on-chip models for RF capacitors and inductors are considered. And the effects of the parasitic component loss in the PI-network are analyzed. Then the circuit is simplified according to the sensitivities of the elements. Therefore, the computational complexity is dramatically reduced. Finally, the AQPSO algorithm is adopted to maximize the power transmission efficiency. Simulation results show that the proposed tuning technique can achieve good accuracy of impedance matching and load power. The reflection coefficient and VSWR obtained are also satisfactory. Moreover, the proposed method can be useful for software defined radio systems using a single antenna for multiple mobile and wireless bands.

  4. Wavelet network based predistortion method for wideband RF power amplifiers exhibiting memory effects

    Institute of Scientific and Technical Information of China (English)

    JIN Zhe; SONG Zhi-huan; HE Jia-ming

    2007-01-01

    RF power amplifiers (PAs) are usually considered as memoryless devices in most existing predistortion techniques.Nevertheless, in wideband communication systems, PA memory effects can no longer be ignored and memoryless predistortion cannot linearize PAs effectively. After analyzing PA memory effects, a novel predistortion method based on wavelet networks (WNs) is proposed to linearize wideband RF power amplifiers. A complex wavelet network with tapped delay lines is applied to construct the predistorter and then a complex backpropagation algorithm is developed to train the predistorter parameters. The simulation results show that compared with the previously published feed-forward neural network predistortion method, the proposed method provides faster convergence rate and better performance in reducing out-of-band spectral regrowth.

  5. Inkjet Printing of Paper-Based Wideband and High Gain Antennas

    KAUST Repository

    Cook, Benjamin

    2011-12-07

    This thesis represents a major contribution to wideband and high gain inkjet-printed antennas on paper. This work includes the complete characterization of the inkjet printing process for passive microwave devices on paper substrate as well as several ultra-wideband and high gain antenna designs. The characterization work includes the electrical characterization of the permittivity and loss tangent for paper substrate through 10 GHz, ink conductivity data for variable sintering conditions, and minimum feature sizes obtainable by today’s current inkjet processes for metallic nanoparticles. For the first time ever, inkjet-printed antennas are demonstrated that operate over the entire UWB band and demonstrate gains up to 8dB. This work also presents the first fractal-based inkjet-printed antennas with enhanced bandwidth and reduced production costs, and a novel slow wave log periodic dipole array which shows minimizations of 20% in width over conventional log periodic antennas.

  6. Multiband and wideband monopole antenna for GSM900 and other wireless applications

    KAUST Repository

    Abutarboush, Hattan

    2012-01-01

    In this letter, the design of a compact monopole antenna for multiband and wideband operations is proposed. The antenna has three distinct frequency bands, centered at 0.94, 2.7, and 4.75 GHz. The antenna has a compact size of only 30×40×1.57 mm$ 3 including the ground plane. The multiband and wideband operations are achieved by using an E-shaped slot on the ground plane. The design procedure is also discussed. The frequency bands can be independently controlled by using the parameters of the E-slot. The impedance bandwidth, current distributions, radiation patterns, gain, and efficiency of the antenna are studied by computer simulation and measurements. © 2011 IEEE.

  7. A wideband textile antenna with a ring-slotted AMC plane

    Science.gov (United States)

    Hussin, Ezzaty Faridah Nor Mohd; Soh, Ping Jack; Jamlos, Mohd Faizal; Lago, Herwansyah; Al-Hadi, Azremi Abdullah; Rahiman, Mohd Hafiz Fazalul

    2017-01-01

    A wideband microstrip-based textile planar antenna with artificial magnetic conductor (AMC) plane is presented. The antenna is initially designed using the combination of two rectangular microstrip antennas operating at 1.5 and 2.5 GHz before being further optimized for wideband operation using various broadbanding techniques. This optimized radiator is then placed over an array of unit elements forming an AMC plane. Each unit element is formed using a square patch slotted using a circular ring and is designed to resonate at 2 GHz. To validate the contribution of the AMC plane in reducing backward radiation toward the human user, the performance of the proposed antenna is compared to a similar antenna without the AMC plane. This investigation indicated that the proposed antenna is capable of reducing backlobe while simultaneously increasing gain to 3.38 dB and improving bandwidth up to 52%.

  8. Micro-Doppler Ambiguity Resolution for Wideband Terahertz Radar Using Intra-Pulse Interference.

    Science.gov (United States)

    Yang, Qi; Qin, Yuliang; Deng, Bin; Wang, Hongqiang; You, Peng

    2017-04-29

    Micro-Doppler, induced by micro-motion of targets, is an important characteristic of target recognition once extracted via parameter estimation methods. However, micro-Doppler is usually too significant to result in ambiguity in the terahertz band because of its relatively high carrier frequency. Thus, a micro-Doppler ambiguity resolution method for wideband terahertz radar using intra-pulse interference is proposed in this paper. The micro-Doppler can be reduced several dozen times its true value to avoid ambiguity through intra-pulse interference processing. The effectiveness of this method is proved by experiments based on a 0.22 THz wideband radar system, and its high estimation precision and excellent noise immunity are verified by Monte Carlo simulation.

  9. A Wideband Slotted Kicker Design for SPS Transverse Intra-Bunch Feedback

    CERN Document Server

    Cesaratto, John M; DeSantis, S; Drago, A; Fox, J D; Gallo, A; Hofle, W; Marcellini, F; Rivetta, C H; Zobov, M

    2013-01-01

    Control and mitigation of transverse beam instabilities caused by electron cloud and TMCI will be essential for the SPS to meet the beam intensity demands for the HL-LHC upgrade. A wideband intra-bunch feedback method is in development, based on a 4 GS/s data acquisition and processing, and with a back end frequency structure extending to 1 GHz. A slotted type kicker, similar to those used for stochastic cooling, has been considered as the terminal element of the feedback chain. It offers the most promising deflecting structure characteristics to meet the system requirements in terms of bandwidth, shunt impedance, and beam coupling impedance. Different types of slotted structures have been explored and simulated, including a ridged waveguide and coaxial type waveguide. In this paper we present our findings and the conceptual design of a vertical SPS wideband kicker consistent with the stay clear, vacuum, frequency band coverage, and peak shunt impedance requirements.

  10. Micro-Doppler Ambiguity Resolution for Wideband Terahertz Radar Using Intra-Pulse Interference

    Directory of Open Access Journals (Sweden)

    Qi Yang

    2017-04-01

    Full Text Available Micro-Doppler, induced by micro-motion of targets, is an important characteristic of target recognition once extracted via parameter estimation methods. However, micro-Doppler is usually too significant to result in ambiguity in the terahertz band because of its relatively high carrier frequency. Thus, a micro-Doppler ambiguity resolution method for wideband terahertz radar using intra-pulse interference is proposed in this paper. The micro-Doppler can be reduced several dozen times its true value to avoid ambiguity through intra-pulse interference processing. The effectiveness of this method is proved by experiments based on a 0.22 THz wideband radar system, and its high estimation precision and excellent noise immunity are verified by Monte Carlo simulation.

  11. Exposure to industrial wideband noise increases connective tissue in the rat liver

    Directory of Open Access Journals (Sweden)

    Maria João R Oliveira

    2012-01-01

    Full Text Available Rats were daily exposed (eight hours/day for a period of four weeks to the same high-intensity wideband noise that was recorded before in a large textile plant. Histologic observation of liver sections of the rats was used to perform quantitative comparison of hepatic connective tissue (dyed by Masson trichromic staining between the noise-exposed and control animals. For that, we have photographed at random centrolobular areas of stained rat liver sections. We found that noise exposure resulted in significant enhancement in the area of collagen-rich connective tissue present in the centrolobular domain of the rat liver. Our data strengthen previous evidence showing that fibrotic transformation is a systemic effect of chronic exposure of rodents and humans to industrial wideband noise.

  12. Wideband Excitation of Microbubbles to Maximize the Sonoporation Efficiency and Contrast in Ultrasound Imaging

    CERN Document Server

    Harput, Sevan; Cowell, David M J; Freear, Steven

    2016-01-01

    The importance of the excitation bandwidth is well known in diagnostic ultrasound imaging. However, the effect of excitation bandwidth in therapeutic applications of microbubbles has been mostly overlooked. A majority of contrast agent production techniques generate polydisperse microbubble populations, so a wide range of resonance frequencies exist. Therefore, wideband excitation is necessary to fully utilize microbubble resonance behavior and maximize the reradiated energy from a microbubble population, both for imaging and therapy. Oscillations of sixty SonoVue microbubbles in proximity of a rigid boundary were captured on a high speed camera at 3 Mfps, excited with a peak negative pressure of 50 kPa at 1 MHz. Measurements were analyzed according to their peak radiated pressure, radial oscillations, root mean squared pressure, and shear stress generated by microbubbles. Results showed that long duration and wideband excitation at low intensity levels was preferable for sonoporation, where microbubbles can ...

  13. DOA estimation of wideband signals based on slice-sparse representation

    Science.gov (United States)

    Gan, Lu; Wang, Xiaoqing

    2013-12-01

    In this article, the direction-of-arrival (DOA) estimation problem of wideband signal sources is studied. We pass the incident signals through a bank of narrowband filters to split the array outputs into several narrowband components. Then, a novel slice-sparse representation model of the joint narrowband array covariance data is proposed in the frequency domain to enforce joint sparsity in the concatenated covariance matrix of all frequencies. Based on the greed matching pursuit algorithm, a multiple measurement slices orthogonal matching pursuit algorithm is proposed to exploit the joint frequency processing in the case of wideband scenarios. The DOA estimation is achieved by joint processing of the array covariance data at different frequency bins. The estimated performance is compared with the representative DOA estimation methods. Simulation experiments are conducted to validate the effectiveness of the proposed method.

  14. DOA estimation of coherent wideband signals based on extended TOPS algorithm

    Science.gov (United States)

    Guo, Rui; Li, Weixing; Zhang, Yue; Chen, Zengping

    2015-12-01

    In this paper, we present a new direction of arrival (DOA) estimation algorithm for coherent wideband signals. This algorithm is based on the test of orthogonality of projected subspaces (TOPS) method which will fail to work in real environments where signals are highly correlated or coherent due to multipath propagation. In order to overcome the disadvantage, we combine spatial smoothing techniques with TOPS method so that the rank of covariance matrix is equal to the number of signal sources even signals received are coherent. Unlike other coherent wideband methods, such as the coherent signal subspace method (CSSM) and WAVES, the new method does not require any initial DOA estimation, thus avoiding errors brought by incorrect initial values. Simulations on computer and experiments in the anechoic chamber based on an 8-elements digital array radar test-bed operating at L & S band are carried out. Simulation and experimental results validate the effectiveness of proposed algorithm.

  15. Zodiacal light dynamics experiment: A wideband imaging Fabry-Perot interferometer

    Science.gov (United States)

    Torr, D. G.; Young, E.; Torr, M. R.; Nagy, A. F.

    1978-01-01

    The Solar Probe will provide an ideal platform from which to study dynamics of dust particles near the sun by measuring the detailed character of the Fraunhofer structure of the zodiacal light. The suggested instrument is a wideband imaging Fabry-Perot interferometer with state of the art technology in both the optics and the detector. The instrument would function as a high-resolution imaging device providing wavelength resolution of 0.03 A over about a 20 A range. The wideband imaging capability would provide sky maps of the zodiacal light on a despun spacecraft without mechanical scanning. The Solar Probe mission would allow the velocity distribution of the dust to be mapped along most of the trajectory of the spacecraft.

  16. Approach for wideband direction-of-arrival estimation in the presence of array model errors

    Institute of Scientific and Technical Information of China (English)

    Chen Deli; Zhang Cong; Tao Huamin; Lu Huanzhang

    2009-01-01

    The presence of array imperfection and mutual coupling in sensor arrays poses several challenges for development of effective algorithms for the direction-of-arrival (DOA) estimation problem in array processing. A correlation domain wideband DOA estimation algorithm without array calibration is proposed, to deal with these array model errors, using the arbitrary antenna array of omnidirectional elements. By using the matrix operators that have the memory and oblivion characteristics, this algorithm can separate the incident signals effectively. Compared with other typical wideband DOA estimation algorithms based on the subspace theory, this algorithm can get robust DOA estimation with regard to position error, gain-phase error, and mutual coupling, by utilizing a relaxation technique based on signal separation. The signal separation category and the robustness of this algorithm to the array model errors are analyzed and proved. The validity and robustness of this algorithm, in the presence of array model errors, are confirmed by theoretical analysis and simulation results.

  17. Wideband absorption in fibonacci quasi-periodic graphene-based hyperbolic metamaterials

    Science.gov (United States)

    Ning, Renxia; Liu, Shaobin; Zhang, Haifeng; Kong, Xiangkun; Bian, Borui; Bao, Jie

    2014-12-01

    A heterostructure containing a Fibonacci quasi-periodic layer and a resonant metal back reflector is proposed, which can realize wideband absorption. The Fibonacci layer is composed of graphene-based hyperbolic metamaterials and isotropic media to obtain wideband absorption. To enhance absorption, an impedance-matching layer is put on top of the Fibonacci layer. It is shown to absorb roughly 90% of all available electromagnetic waves in an 11 terahertz absorption bandwidth for a transverse magnetic mode at normal angle incidence. The absorption bandwidth is affected by the reflection band gap. Compared with some previous designs, our proposed structure has a larger absorption bandwidth and higher absorption in the mid-infrared range. The results should be valuable in the design of infrared stealth and broadband optoelectronic devices.

  18. 67 cm long bismuth-based erbium doped fiber amplifier with wideband operation

    Science.gov (United States)

    Cheng, X. S.; Hamida, B. A.; Naji, A. W.; Ahmad, H.; Harun, S. W.

    2011-11-01

    In this paper, we demonstrate a wideband Bismuth-based erbium doped fiber amplifier (Bi-EDFA) using two pieces of bismuth-based erbium-doped fiber (Bi-EDF) with a total length of 67 cm as gain media in a double pass parallel configuration. Both Bi-EDFs have an erbium ion concentration of 6300 ppm. Compared to conventional silica-based erbium-doped fiber amplifier (Si-EDFA) with the same amount of erbium ions, the Bi-EDFA provides a higher attainable gain as well as a greater amplification bandwidth, which ranging from 1525 to 1620 nm. The proposed Bi-EDFA achieved a wideband gain of around 18 dB within the wavelength region from 1530 to 1565 nm. The noise figures are maintained below 10 dB within a wide wavelength region from 1535 nm to 1620 nm.

  19. Experimental and Theoretical Investigation of Directional Wideband Electromagnetic Pulse Photoemission Generator

    Science.gov (United States)

    Petrov, P. V.; Afonin, V. I.; Zamuraev, D. O.; Zavolokov, E. V.; Kupyrin, N. V.; Lazarev, Yu. N.; Romanov, Yu. O.; Syrtsova, Yu. G.; Sorokin, I. A.; Tischenko, A. S.; Brukhnevich, G. I.; Voronkova, N. P.; Pekarskaya, L. Z.; Belolipetskiy, V. S.

    The effect of electromagnetic wave generation by the electric current pulse propagating at the superluminal velocity along a conducting surface might be promising to create a high-power wideband microwave generator. The system comprising a plane vacuum photodiode with a transparent anode and using laser radiation to initialize electron emission is a variant to realize this scheme of electromagnetic pulse generation. This chapter presents results of experimental researches in characteristics of such radiating element with the cesium-antimonide cathode of Ø50 mm. The performed researches have shown that the generated wideband pulse (f_0 ≈ 3.3 {{GHz}},Δ f/f_0 ˜ 1) propagates in the direction corresponding to specular reflection of the incident laser radiation. Under the voltage of about 50 kV the electric field strength of 44 kV/m at the distance of 1.3 m has been recorded that corresponds to the generator power ˜10 MW.

  20. FREQUENCY ESTIMATION OF SINUSIODE FROM WIDEBAND USING SUB-NYQUIST SAMPLING

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A novel frequency estimation algorithm for wideband signal with sub-Nyquist sampling is pro-posed in this paper. With the aid of information provided by the auxiliary delayed sampling channel and thealiased frequency estimation for wideband signal with sub-Nyquist sampling, the frequency aliasing due tosub-Nyquist sampling can be solved. This method can reduce the complexity of the overall hardware at thecost of an auxiliary sampling channel. Furthermore, in order to alleviate the computation burden for its practi-cability, a more simplified algorithm is put forward and its validity is proved by our numerical simulation re-sults. The Cramer-Rao Lower Bound (CRLB) of the frequency estimation is also derived at the end of this pa-per.

  1. Compact Wideband and Low-Profile Antenna Mountable on Large Metallic Surfaces

    DEFF Research Database (Denmark)

    Zhang, Shuai; Pedersen, Gert F.

    2017-01-01

    resonance at the lowest frequency. A trapezoid-shaped capacitive-feed (C-fed) strip is utilized and also printed on the Teflon block to globally optimize the wideband impedance matching. The proposed antenna covers a relative bandwidth of 109% for VSWR...This paper proposes a compact wideband and low-profile antenna mountable on large metallic surfaces. Six rows of coupled microstrip resonators with different lengths are printed on a Teflon block. The lengths of the microstrip resonators in different rows are gradually reduced along the end......-fire direction. The first four rows of resonators provide four resonances at different frequencies for bandwidth enhancement. The last two rows of resonators are used as two directors to suppress sidelobe levels at high frequencies. A trapezoidal launcher is applied to serve as a reflector and provide one...

  2. Wideband laser locking to an atomic reference with modulation transfer spectroscopy.

    Science.gov (United States)

    Negnevitsky, V; Turner, L D

    2013-02-11

    We demonstrate that conventional modulated spectroscopy apparatus, used for laser frequency stabilization in many atomic physics laboratories, can be enhanced to provide a wideband lock delivering deep suppression of frequency noise across the acoustic range. Using an acousto-optic modulator driven with an agile oscillator, we show that wideband frequency modulation of the pump laser in modulation transfer spectroscopy produces the unique single lock-point spectrum previously demonstrated with electro-optic phase modulation. We achieve a laser lock with 100 kHz feedback bandwidth, limited by our laser control electronics. This bandwidth is sufficient to reduce frequency noise by 30 dB across the acoustic range and narrows the imputed linewidth by a factor of five.

  3. Generalized Analysis Method for a Class of Novel Wideband Loaded-Stub Phase Shifters

    Directory of Open Access Journals (Sweden)

    Sensong An

    2015-12-01

    Full Text Available In this paper, an analysis method of wideband loaded-stub phase shifters and a fast designing procedure is presented. These kinds of phase shifters use a transmission line loaded with one or two open stubs and a reference line to achieve up to 135° phase shift. Analysis results shows that lower than -10dB return loss and precise phase shift can be achieved over a 100% bandwidth employing the ideal open stubs. To approach the ideal impedance value of the open stubs, an arrow-shaped stub and several means to control its impedance is proposed. As verification of the analysis method, a 90° two-stub loaded phase shifter is easily designed and fabricated. Measured results show the design achieves better than ±4° phase ripple, less than 0.5dB insertion loss, and better than 10dB return loss over an 85% wideband.

  4. Photopyroelectric Monitoring of Olive's Ripening Conditions and Olive Oil Quality Using Pulsed Wideband IR Thermal Source

    Science.gov (United States)

    Abu-Taha, M. I.; Sarahneh, Y.; Saleh, A. M.

    The present study is based on band absorption of radiation from pulsed wideband infrared (IR) thermal source (PWBS) in conjunction with polyvinylidene fluoride film (PVDF). It is the first time to be employed to monitor the ripening state of olive fruit. Olive's characteristics vary at different stages of ripening, and hence, cultivation of olives at the right time is important in ensuring the best oil quality and maximizes the harvest yield. The photopyroelectric (PPE) signal resulting from absorption of wideband infrared (IR) radiation by fresh olive juice indicates the ripening stage of olives, i.e., allows an estimate of the suitable harvest time. The technique was found to be very useful in discriminating between olive oil samples according to geographical region, shelf life, some storage conditions, and deliberate adulteration. Our results for monitoring oil accumulation in olives during the ripening season agree well with the complicated analytical studies carried out by other researchers.

  5. Ultra-wideband wireless receiver front-end for high-speed indoor applications

    Directory of Open Access Journals (Sweden)

    Zhe-Yang Huang

    2014-12-01

    Full Text Available Low-noise, ultra-wideband (UWB wireless receiver front-end circuits were presented in this study. A two-stage common-source low-noise amplifier with wideband input impedance matching network, an active-balun and a double-balanced down-conversion mixer were adopted in the UWB wireless receiver front-end. The proposed wireless receiver front-end circuits were implemented in 0.18 μm radio-frequency-CMOS process. The maximum down-conversion power gain of the front-end is 25.8 dB; minimum single-sideband noise figure of the front-end is 4.9 dB over complete UWB band ranging from 3.1 to 10.6 GHz. Power consumption including buffers is 39.2 mW.

  6. Design of an 8-40 GHz Antenna for the Wideband Instrument for Snow Measurements (WISM)

    Science.gov (United States)

    Durham, Timothy E.; Vanhille, Kenneth J.; Trent, Christopher; Lambert, Kevin M.; Miranda, Felix A.

    2015-01-01

    Measurement of land surface snow remains a significant challenge in the remote sensing arena. Developing the tools needed to remotely measure Snow Water Equivalent (SWE) is an important priority. The Wideband Instrument for Snow Measurements (WISM) is being developed to address this need. WISM is an airborne instrument comprised of a dual-frequency (X- and Ku-bands) Synthetic Aperture Radar (SAR) and dual-frequency (K- and Ka-bands) radiometer. A unique feature of this instrument is that all measurement bands share a common antenna aperture consisting of an array feed reflector that covers the entire bandwidth. This paper covers the design and fabrication of the wideband array feed which is based on tightly coupled dipole arrays. Implementation using a relatively new multi-layer microfabrication process results in a small, 6x6 element, dual-linear polarized array with beamformer that operates from 8 to 40 gigahertz.

  7. 35 Gb/s Ultra-wideband Technology for Advanced Communications

    DEFF Research Database (Denmark)

    Puerta Ramírez, Rafael; Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

    as ordinary noise. Furthermore, this technology allows unlicensed operation, provided standards and regulations are fulfilled. On the other hand, in current fast evolving scenarios, secure communications at the physical layer will soon become a requirement by the end users. Existing security techniques...... be applied, evolving from classic spectral inefficient pulsebased systems to more advanced and flexible modulation schemes. Ultra-wideband technology is suitable for low-power high-speed wireless communication systems over short distances, and is an appealing alternative for next generation networks ranging...... from high-speed wireless personal area networks, to the internet of things applications. Its popularity stems from the fact that they can be used as an overlay to existing systems, without interference, operating in parallel to existing wireless systems, which perceive ultra-wideband emissions...

  8. Note: Development of a wideband amplifier for cryogenic scanning tunneling microscopy

    Science.gov (United States)

    Zhang, Chao; Jeon, Hoyeon; Oh, Myungchul; Lee, Minjun; Kim, Sungmin; Yi, Sunwouk; Lee, Hanho; Zoh, Inhae; Yoo, Yongchan; Kuk, Young

    2017-06-01

    A wideband cryogenic amplifier has been developed for low temperature scanning tunneling microscopy. The amplifier consisting of a wideband complementary metal oxide semiconductor field effect transistors operational amplifier together with a feedback resistor of 100 kΩ and a capacitor is mounted within a 4 K Dewar. This amplifier has a wide bandwidth and is successfully applied to scanning tunneling microscopy applications at low temperatures down to ˜7 K. The quality of the designed amplifier is validated by high resolution imaging. More importantly, the amplifier has also proved to be capable of performing scanning tunneling spectroscopy measurements, showing the detection of the Shockley surface state of the Au(111) surface and the superconducting gap of Nb(110).

  9. Analysis and Design of Tapered Slot Antenna for Ultra-Wideband Applications

    Institute of Scientific and Technical Information of China (English)

    YAO Yuan; CHEN Wenhua; HUANG Bin; FENG Zhenghe; ZHANG Zhijun

    2009-01-01

    The tapered slot antenna,such as Vivaldi,has been widely used due to its ultra-wideband,high gain,simple feed structure,and easy fabrication.However,there is no rigorous analytical theory for this type of antenna.This paper analyzed the metal parts of a tapered slot antenna in a conical coordinate system with the medium analyzed in rectangular coordinates.This mixed mode gave an approximate analytical form for the tapered slot antenna with the field distribution and radiation characteristics.A planar tapered slot antenna was proposed according to the results of the analysis methods.Measured and simulated results demonstrate the antenna performance.The antenna shows good impedance matching over a wide bandwidth of 9 GHz,from 2 GHz to 11 GHz,and good radiation patterns.It is suitable for ultra-wideband applications.

  10. Design of a Compact Wideband Antenna Array for Microwave Imaging Applications

    Directory of Open Access Journals (Sweden)

    J. Puskely

    2013-12-01

    Full Text Available In the paper, wideband antenna arrays aimed at microwave imaging applications and SAR applications operating at Ka band were designed. The antenna array feeding network is realized by a low-loss SIW technology. Moreover, we have replaced the large feed network comprised of various T and Y junctions by a simple broadband network of compact size to more reduce losses in the substrate integrated waveguide and also save space on the PCB. The designed power 8-way divider is complemented by a wideband substrate integrated waveguide to a grounded coplanar waveguide transition and directly connected to the antenna elements. The measured results of antenna array are consistent with our simulation. Obtained results of the developed array demonstrated improvement compared to previously developed binary feed networks with microstrip or SIW splitters.

  11. Design and study of a compact planar ultra-wideband antenna

    Institute of Scientific and Technical Information of China (English)

    CHENG Yong; LU Wenjun; CHENG Chonghu; CAO Wei

    2007-01-01

    In this paper,a novel,small,and compact planar antenna for ultra-wideband(UWB)applications is proposed.The antenna is an extension of microstrip slot antenna technology.To achieve ultra-wideband characteristics,a tapered microstrip fork-shaped stub has been employed.A symmetric polygon wide slot has been placed on the antenna ground.The design was investigated numerically to obtain proper dimensions for the antenna and a prototype was constructed.The return loss,pattern and gain of the prototype antenna have been measured.The transient pulse signal fidelity has also been investigated by finite-difference time-domain (FDTD)method.Experimental results show that the proposed antenna design has promising characteristics for UWB applications.

  12. STOCHASTIC OPTIMAL CONTROL OF STRONGLY NONLINEAR SYSTEMS UNDER WIDE-BAND RANDOM EXCITATION WITH ACTUATOR SATURATION

    Institute of Scientific and Technical Information of China (English)

    Changshui Feng; Weiqiu Zhu

    2008-01-01

    A bounded optimal control strategy for strongly non-linear systems under non-white wide-band random excitation with actuator saturation is proposed. First, the stochastic averaging method is introduced for controlled strongly non-linear systems under wide-band random excitation using generalized harmonic functions. Then, the dynamical programming equation for the saturated control problem is formulated from the partially averaged Ito equation based on the dynamical programming principle. The optimal control consisting of the unbounded optimal control and the bounded bang-bang control is determined by solving the dynamical programming equation. Finally, the response of the optimally controlled system is predicted by solving the reduced Fokker-Planck-Kolmogorov (FPK) equation associated with the completed averaged Ito equation. An example is given to illustrate the proposed control strategy. Numerical results show that the proposed control strategy has high control effectiveness and efficiency and the chattering is reduced significantly comparing with the bang-bang control strategy.

  13. A system architecture for an advanced Canadian wideband mobile satellite system

    Science.gov (United States)

    Takats, P.; Keelty, M.; Moody, H.

    In this paper, the system architecture for an advanced Canadian ka-band geostationary mobile satellite system is described, utilizing hopping spot beams to support a 256 kbps wideband service for both N-ISDN and packet-switched interconnectivity to small briefcase-size portable and mobile terminals. An assessment is given of the technical feasibility of the satellite payload and terminal design in the post year 2000 timeframe. The satellite payload includes regeneration and on-board switching to permit single hop interconnectivity between mobile terminals. The mobile terminal requires antenna tracking and platform stabilization to ensure acquisition of the satellite signal. The potential user applications targeted for this wideband service includes: home-office, multimedia, desk-top (PC) videoconferencing, digital audio broadcasting, single and multi-user personal communications.

  14. 10th and 11th conference on Ultra-Wideband Short-Pulse Electromagnetics

    CERN Document Server

    Mokole, Eric; UWB SP 10; UWB SP 11

    2014-01-01

    This book presents contributions of deep technical content and high scientific quality in the areas of electromagnetic theory, scattering, UWB antennas, UWB systems, ground penetrating radar (GPR), UWB communications, pulsed-power generation, time-domain computational electromagnetics, UWB compatibility, target detection and discrimination, propagation through dispersive media, and wavelet and multi-resolution techniques. Ultra-wideband (UWB), short-pulse (SP) electromagnetics are now being used for an increasingly wide variety of applications, including collision avoidance radar, concealed object detection, and communications. Notable progress in UWB and SP technologies has been achieved by investigations of their theoretical bases and improvements in solid-state manufacturing, computers, and digitizers. UWB radar systems are also being used for mine clearing, oil pipeline inspections, archeology, geology, and electronic effects testing. Like previous books in this series, Ultra-Wideband Short-Pulse Electrom...

  15. 7th conference on ultra-wideband, short-pulse electromagnetics

    CERN Document Server

    Schenk, Uwe; Nitsch, Daniel; Sabath, Frank; Ultra-Wideband, Short-Pulse Electromagnetics 7; UWBSP7

    2007-01-01

    Ultra-wideband (UWB), short-pulse (SP) electromagnetics are now being used for an increasingly wide variety of applications, including collision avoidance radar, concealed object detection, and communications. Notable progress in UWB and SP technologies has been achieved by investigations of their theoretical bases and improvements in solid-state manufacturing, computers, and digitizers. UWB radar systems are also being used for mine clearing, oil pipeline inspections, archeology, geology, and electronic effects testing. Ultra-Wideband Short-Pulse Electromagnetics 7 presents selected papers of deep technical content and high scientific quality from the UWB-SP7 Conference, including wide-ranging contributions on electromagnetic theory, scattering, UWB antennas, UWB systems, ground penetrating radar (GPR), UWB communications, pulsed-power generation, time-domain computational electromagnetics, UWB compatibility, target detection and discrimination, propagation through dispersive media, and wavelet and multi-res...

  16. Spatial Dynamic Wideband Modeling of the MIMO Satellite-to-Earth Channel

    Directory of Open Access Journals (Sweden)

    Andreas Lehner

    2014-01-01

    response (CIR time series depending on the movement profile of a land mobile terminal is presented in this paper. Based on high precise wideband measurements in L-band the model reproduces the correlated shadowing and multipath conditions in rich detail. The model includes time and space variant echo signals appearing and disappearing in dependence on the receive antenna position and movement, and the actual azimuths and elevations to the various signal sources. Attenuation and path delays relative to the hypothetical line of sight (LOS ensure usability for ranging purposes. Parameters for car and pedestrian applications in urban and suburban environments are provided. The channel characteristics are determined independently of the transmitted signal. Therefore the usability, for example, for GPS and GALILEO, as well as wideband communication services from hovering platforms, is given.

  17. Target Recognition Using Late-Time Returns from Ultra-Wideband, Short-Pulse Radar

    Science.gov (United States)

    2004-06-01

    WIDEBAND, SHORT-PULSE RADAR DISSERTATION Kenneth J. Pascoe, B.S.E.E., M.S. Major, USAF Approved: Dr. Michael J. Havrilla Dissertation Advisor Date Dr...Acknowledgments Thanks to all the people who helped to make this research happen. Thanks to my committee: Dr. Michael Havrilla , the late Major Bill Wood...Singularity Expansion Method 16. SECURITY CLASSIFICATION OF: 19a. NAME OF RESPONSIBLE PERSON Michael J. Havrilla , Ph.D. (ENG) a. REPORT U b

  18. Wideband Analog Transmission System Based on the External Intensity Electro-Optic Modulator

    Directory of Open Access Journals (Sweden)

    Jiri Svarny

    2016-01-01

    Full Text Available The work deals with design and integration of an analog electro-optic transmission system suitable for some specialized tasks of diagnostics and measurements. The system is based on principle of external intensity modulation of fiber guided laser radiation. Besides wideband and almost lossless transmission the system tolerates extreme length of the transmitting medium and ensures ultimate galvanic barrier between the input and output.

  19. Miniature and Wide-Band ILA Antenna with Non-Foster Matching

    OpenAIRE

    Haskou, Abdullah; Lemur, Dominique; Collardey, Sylvain; Sharaiha, Ala

    2016-01-01

    International audience; In this paper, we present a miniature, wide-band, Inverted L Antenna (ILA) with non-Foster matching. The antenna size is 9.5 × 19.5 mm 2 and it is integrated on a Printed Circuit Board (PCB) of 100 × 60 mm 2. The antenna covers the whole frequency band of (0.76 − 2.17) GHz and the circuit is stable throughout this band.

  20. High-speed ultra-wideband wireless signals over fiber systems: photonic generation and DSP detection

    DEFF Research Database (Denmark)

    Yu, Xianbin; Gibbon, Timothy Braidwood; Tafur Monroy, Idelfonso

    2009-01-01

    We firstly review the efforts in the literature on ultra-wideband (UWB)-over-fiber systems. Secondly, we present experimental results on photonic generation of high-speed UWB signals by both direct modulation and external optical injecting an uncooled semiconductor laser. Furthermore, we introduc...... the use of digital signal processing (DSP) technology to receive the generated UWB signal at 781.25 Mbit/s. Error-free transmission is achieved....

  1. Evaluation of pre-filtering techniques for delay-spread compression in Wideband MISO systems

    OpenAIRE

    Comas Massague, Armand

    2017-01-01

    This thesis describes in quite depth the channel behaviour in wireless communications, pointing some of the complexities that communication systems must face. The document is then focused in Delay Spread Compression (DSC) as one of the solutions to significant problems in Wideband communications. With this objective, Time Reversal (TR) in its simplest mode has been studied and implemented in Matlab for a Multiple-Input Single-Output (MISO) system. Then, a possible upgrade has been done regard...

  2. Breath air measurement using wide-band frequency tuning IR laser photo-acoustic spectroscopy

    Science.gov (United States)

    Kistenev, Yury V.; Borisov, Alexey V.; Kuzmin, Dmitry A.; Bulanova, Anna A.; Boyko, Andrey A.; Kostyukova, Nadezhda Y.; Karapuzikov, Alexey A.

    2016-03-01

    The results of measuring of biomarkers in breath air of patients with broncho-pulmonary diseases using wide-band frequency tuning IR laser photo-acoustic spectroscopy and the methods of data mining are presented. We will discuss experimental equipment and various methods of intellectual analysis of the experimental spectra in context of above task. The work was carried out with partial financial support of the FCPIR contract No 14.578.21.0082 (ID RFMEFI57814X0082).

  3. Absolute calibration of a wideband antenna and spectrometer for sky noise spectral index measurements

    CERN Document Server

    Rogers, Alan E E

    2012-01-01

    A new method of absolute calibration of sky noise temperature using a three-position switched spectrometer, measurements of antenna and low noise amplifier impedance with a vector network analyzer, and ancillary measurements of the amplifier noise waves is described. The details of the method and its application to accurate wideband measurements of the spectral index of the sky noise are described and compared with other methods.

  4. Miniaturized Wideband Aperture Coupled Microstrip Patch Antenna by Using Inverted U-Slot

    OpenAIRE

    2014-01-01

    This paper presents a linear polarized aperture coupled inverted U-slot patch antenna with small steps at the edges. The proposed design exhibits wideband behavior, acceptable return loss, VSWR, gain, small size, and less complexity. The theoretical analysis is based on the finite element method (FEM). This design has wide bandwidth, good return loss, VSWR, and radiation characteristics by implanting the inverted U-shaped stepped slots on a single aperture coupled patch. The proposed antenna ...

  5. Mid-Latitude Mobile Wideband HF- NVIS Channel Analysis: Part 1

    Science.gov (United States)

    2017-09-14

    communications (SATCOM) for beyond line-of- sight (LOS) links. However, standard HF systems operating over a 3-kHz bandwidth do not provide sufficient...wideband mid-latitude HF channel soundings and three-dimensional (3-D) ray-tracing simulations to develop a statistical model of a particular nearly...46 5 THE HF-NVIS CHANNEL SOUNDING SYSTEM ...................................................................... 47 5.1 TRANSMIT AND RECEIVE HF

  6. A wide-band dielectric characterization system for liquid materials of interest in biology

    OpenAIRE

    Bramanti, Mauro

    1995-01-01

    In many fields of applied research the interest exhists for wide-band dielectric ,characterization of liquid materials, for example, aqueous solutions of biological materials. For this purpose a particular procedure is here proposed, based on the use of a Vectorial Network Analyzer and a suitably designed cell which contains the material under test. Fundamental features of this method are: dielectric characterization directly in the frequency domain without the use of a Fourier inverse trasfo...

  7. Development of a Wideband Compact Orthomode Transducer for the 180-270 GHz Band

    Science.gov (United States)

    Leal-Sevillano, Carlos A.; Reck, Theodore J.; Chattopadhyay, Goutam; Ruiz-Cruz, Jorge A.; Montejo-Garai, Jose R.; Rebollar, Jesus M.

    2014-09-01

    In this paper, we report the development of a wideband compact orthomode transducer (OMT) for the 180-270 GHz band. The OMT design is based on the classical high performance Bøifot waveguide junction and implemented in split-block using high precision CNC milling. The obtained results validate the high performance operation in a 40% fractional bandwidth and constitute a remarkable achievement at this high frequency band.

  8. Design and Simulation of Sub Nanosecond Pulse Generator for Uitra-Wideband Communication

    Institute of Scientific and Technical Information of China (English)

    XU Ping-ping; OUYANG Yong-yan; FAN Xiang-ning

    2003-01-01

    A new sub-nanosecond pulse generator scheme is proposed in the opinion of frequency field in this paper.The filtering techniques used in the UWB (ultra-wideband) generator make the circuit simple and suitable for integration. The theoretical analysis and simulation results show that monocycle form generated in the scheme have a good balance between positive and negative shape and small traipse by circuit parameter control and has improved the quality of UWB pulse form.

  9. Tomographic imaging with ultra-wideband noise radar using time-domain data

    Science.gov (United States)

    Shin, Hee Jung; Narayanan, Ram M.; Rangaswamy, Muralidhar

    2013-05-01

    This paper investigates the feasibility of using a noise waveform in an ultra-wideband (UWB) radar system for two-dimensional tomographic imaging of a stationary object with a multistatic tomographic geometry. Multiple UWB transmitters and receivers are positioned along each side of the imaging area. We perform several numerical simulations in time-domain, and the successful imaging of the target is achieved by visual inspection of the formed images.

  10. Software-Defined Ultra-wideband Radio Communications: A New RF Technology for Emergency Response Applications

    Energy Technology Data Exchange (ETDEWEB)

    Nekoogar, F; Dowla, F

    2009-10-19

    Reliable wireless communication links for local-area (short-range) and regional (long-range) reach capabilities are crucial for emergency response to disasters. Lack of a dependable communication system can result in disruptions in the situational awareness between the local responders in the field and the emergency command and control centers. To date, all wireless communications systems such as cell phones and walkie-talkies use narrowband radio frequency (RF) signaling for data communication. However, the hostile radio propagation environment caused by collapsed structures and rubble in various disaster sites results in significant degradation and attenuation of narrowband RF signals, which ends up in frequent communication breakdowns. To address the challenges of reliable radio communication in disaster fields, we propose an approach to use ultra-wideband (UWB) or wideband RF waveforms for implementation on Software Defined Radio (SDR) platforms. Ultra-wideband communications has been proven by many research groups to be effective in addressing many of the limitations faced by conventional narrowband radio technologies. In addition, LLNL's radio and wireless team have shown significant success in field deployment of various UWB communications system for harsh environments based on LLNL's patented UWB modulation and equalization techniques. Furthermore, using software defined radio platform for UWB communications offers a great deal of flexibility in operational parameters and helps the radio system to dynamically adapt itself to its environment for optimal performance.

  11. Robust Nearfield Wideband Beamforming Design Based on Adaptive-Weighted Convex Optimization

    Directory of Open Access Journals (Sweden)

    Guo Ye-Cai

    2017-01-01

    Full Text Available Nearfield wideband beamformers for microphone arrays have wide applications in multichannel speech enhancement. The nearfield wideband beamformer design based on convex optimization is one of the typical representatives of robust approaches. However, in this approach, the coefficient of convex optimization is a constant, which has not used all the freedom provided by the weighting coefficient efficiently. Therefore, it is still necessary to further improve the performance. To solve this problem, we developed a robust nearfield wideband beamformer design approach based on adaptive-weighted convex optimization. The proposed approach defines an adaptive-weighted function by the adaptive array signal processing theory and adjusts its value flexibly, which has improved the beamforming performance. During each process of the adaptive updating of the weighting function, the convex optimization problem can be formulated as a SOCP (Second-Order Cone Program problem, which could be solved efficiently using the well-established interior-point methods. This method is suitable for the case where the sound source is in the nearfield range, can work well in the presence of microphone mismatches, and is applicable to arbitrary array geometries. Several design examples are presented to verify the effectiveness of the proposed approach and the correctness of the theoretical analysis.

  12. Simple voltage-controlled current source for wideband electrical bioimpedance spectroscopy: circuit dependences and limitations

    Science.gov (United States)

    Seoane, F.; Macías, R.; Bragós, R.; Lindecrantz, K.

    2011-11-01

    In this work, the single Op-Amp with load-in-the-loop topology as a current source is revisited. This circuit topology was already used as a voltage-controlled current source (VCCS) in the 1960s but was left unused when the requirements for higher frequency arose among the applications of electrical bioimpedance (EBI). The aim of the authors is not only limited to show that with the currently available electronic devices it is perfectly viable to use this simple VCCS topology as a working current source for wideband spectroscopy applications of EBI, but also to identify the limitations and the role of each of the circuit components in the most important parameter of a current for wideband applications: the output impedance. The study includes the eventual presence of a stray capacitance and also an original enhancement, driving with current the VCCS. Based on the theoretical analysis and experimental measurements, an accurate model of the output impedance is provided, explaining the role of the main constitutive elements of the circuit in the source's output impedance. Using the topologies presented in this work and the proposed model, any electronic designer can easily implement a simple and efficient current source for wideband EBI spectroscopy applications, e.g. in this study, values above 150 kΩ at 1 MHz have been obtained, which to the knowledge of the authors are the largest values experimentally measured and reported for a current source in EBI at this frequency.

  13. Maximum Likelihood DOA Estimation of Multiple Wideband Sources in the Presence of Nonuniform Sensor Noise

    Directory of Open Access Journals (Sweden)

    K. Yao

    2007-12-01

    Full Text Available We investigate the maximum likelihood (ML direction-of-arrival (DOA estimation of multiple wideband sources in the presence of unknown nonuniform sensor noise. New closed-form expression for the direction estimation Cramér-Rao-Bound (CRB has been derived. The performance of the conventional wideband uniform ML estimator under nonuniform noise has been studied. In order to mitigate the performance degradation caused by the nonuniformity of the noise, a new deterministic wideband nonuniform ML DOA estimator is derived and two associated processing algorithms are proposed. The first algorithm is based on an iterative procedure which stepwise concentrates the log-likelihood function with respect to the DOAs and the noise nuisance parameters, while the second is a noniterative algorithm that maximizes the derived approximately concentrated log-likelihood function. The performance of the proposed algorithms is tested through extensive computer simulations. Simulation results show the stepwise-concentrated ML algorithm (SC-ML requires only a few iterations to converge and both the SC-ML and the approximately-concentrated ML algorithm (AC-ML attain a solution close to the derived CRB at high signal-to-noise ratio.

  14. Wideband characterization of the complex wave number and characteristic impedance of sound absorbers.

    Science.gov (United States)

    Salissou, Yacoubou; Panneton, Raymond

    2010-11-01

    Several methods for measuring the complex wave number and the characteristic impedance of sound absorbers have been proposed in the literature. These methods can be classified into single frequency and wideband methods. In this paper, the main existing methods are revisited and discussed. An alternative method which is not well known or discussed in the literature while exhibiting great potential is also discussed. This method is essentially an improvement of the wideband method described by Iwase et al., rewritten so that the setup is more ISO 10534-2 standard-compliant. Glass wool, melamine foam and acoustical/thermal insulator wool are used to compare the main existing wideband non-iterative methods with this alternative method. It is found that, in the middle and high frequency ranges the alternative method yields results that are comparable in accuracy to the classical two-cavity method and the four-microphone transfer-matrix method. However, in the low frequency range, the alternative method appears to be more accurate than the other methods, especially when measuring the complex wave number.

  15. Performance requirements for analog-to-digital converters in wideband reconfigurable radios

    Science.gov (United States)

    Naughton, David; Baldwin, Gerard; Farrell, Ronan

    2005-06-01

    With the current trend towards software defined radio, several candidate architectures for the analog receiver front-end have been presented. A common proposal for software defined reconfigurable radio is to develop a wideband ADC and utilise this for capturing a large segment of the spectrum. This would enable the subsequent signal processing operations of channel selection and data extraction to be carried out by a digital processor. This would allow the radio to be reconfigured by simply changing the software. In analysis of these systems, powerful neighbouring signals, or blockers, are considered but it has been conveniently assumed that suitable dynamic range will be available at the ADC. This is an acceptable assumption in narrowband systems where automatic gain control and analogue channel select filters can be used, but is not appropriate for a wideband system. In this paper we present an analysis based on bit-error-rates (BER) which shows the effect of blockers in a wideband architecture on the performance of the communication link and on the dynamic range requirements of the ADC.

  16. DrugFacts: Heroin

    Science.gov (United States)

    ... heroin. Other common names for heroin include dope , horse , junk , and smack . How do people use heroin? ... expectations and behaviors, and effectively manage triggers and stress. These behavioral treatment approaches have proven effective, especially ...

  17. Drug Facts

    Medline Plus

    Full Text Available ... Cocaine (Coke, Crack) Facts Heroin (Smack, Junk) Facts Marijuana (Weed, Pot) Facts MDMA (Ecstasy, Molly) Facts Meth (Crank, ... Information About Drugs Alcohol Bath Salts Cocaine Heroin Marijuana MDMA Meth Pain Medicines Spice (K2) Tobacco/Nicotine ...

  18. La ruina de las capitales: A propósito de la incidencia del arte, los objetos ornamentales y el mobiliario urbano, en el espacio público, en el paisaje y en la configuración del territorio

    National Research Council Canada - National Science Library

    Delgado Pérez, German J

    2008-01-01

    .... A large part of national territory has been affected by a multitude of objects, artifacts, mechanisms, sculptures and junk, almost always unnecessary, whose presence is justified by the generic term urban furniture...

  19. Congenital cataract

    Science.gov (United States)

    ... EA, eds. Duane's Ophthalmology . 16th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013:chap 74. Junk AK, Morris ... EA, eds. Duane's Ophthalmology . 16th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013:chap 41. Read More Cataract - ...

  20. Stopping Spam

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Purportedly in an effort to fight fraud and the proliferation of "junk" messages, beginning January the government is requiring mobile phone sub- scribers to register their real names and other personal information, but the move has provoked sharp controversy.