Guidelines for School and Community Cooperation: Implementation on a Gang Prevention Program.

Science.gov (United States)

Thompson, Ronnie; Karr-Kidwell, PJ

Youth gangs are not a new phenomena in the United States; however, in the past decade the number of gang members has increased dramatically. Gang prevention-intervention programs are a necessary part of every school's curriculum. Students join gangs for a variety of reasons ranging from boredom to intent on criminal behavior. One characteristic…

Report on Gang Violence in Maryland

Science.gov (United States)

1994-07-01

crime; others, mainly parents, think of gangs as groups of neighborhood kids seeking companionship to brag about their day’s exploits and express...Ghetto Busters JBM (junior Black Mafia) Jersey Road Boys Kool Aid Kids PRP (Puerto Rican Posse) Skinheads 32 Ounce Posse West Side Boys Yellow Jackets...Graffiti BIG Devils Art Gang DAG East Side Crew ESC East Side Hit Squad ECHS Everlasting Writers ELW Fuck You Crew FYC Furious Fighting Crew FFC Go A Head

Word Embeddings to Enhance Twitter Gang Member Profile Identification

OpenAIRE

Wijeratne, Sanjaya; Balasuriya, Lakshika; Doran, Derek; Sheth, Amit

2016-01-01

Gang affiliates have joined the masses who use social media to share thoughts and actions publicly. Interestingly, they use this public medium to express recent illegal actions, to intimidate others, and to share outrageous images and statements. Agencies able to unearth these profiles may thus be able to anticipate, stop, or hasten the investigation of gang-related crimes. This paper investigates the use of word embeddings to help identify gang members on Twitter. Building on our previous wo...

Is America on the Road to Victory in the Global War on Terrorism

National Research Council Canada - National Science Library

Cunningham, Donald S

2006-01-01

...?nation's leaders define victory for this war, that they re-address their view of the capacity and the identity of the enemy and therefore the length of time required to attain victory, and that they...

The Problem with Templates: Learning from Organic Gang-Related Violence Reduction

Directory of Open Access Journals (Sweden)

Dennis Rodgers

2015-10-01

Full Text Available This article considers what demobilisation, disarmament, and reintegration (DDR programmes might learn from research on gangs and the problems associated with government-instituted ‘wars on gangs’ putatively aimed at reducing or fighting gang-related violence. It begins by considering interventions associated with the global war on gangs, and compares their underlying premises and practices with those of DDR programmes while highlighting how both are plagued with problems associated with drawing on de-contextualized templates. Drawing on long-term ethnographic research carried out in Nicaragua and South Africa, the article then goes on to explore why individuals leave gangs, focusing in particular on the more organic processes that deplete gangs of their members, as well as the consequences that the different possible occupational trajectories of ex-gang members can have for patterns of violence. These offer a number of potential lessons for DDR programmes, particularly with regard to reducing violence in a realistic and sustainable manner.

Can the Jamaican Security Forces Successfully Reduce the Violent Impact of Gangs?

Science.gov (United States)

2012-12-14

El Paso , TX: Scholarly Publishers, 2002), 35. 20 Walter Miller is a Professor of Anthropology at Harvard and MIT. From an academic perspective...percenter outlaw motor cycle gangs,” and “neighborhood gangs.” The definitions of these gangs are limited and fall short of describing OCGs. Even if the...Quoted in Lamm-Weiss. Contemporary Gangs: An Organizational Analysis. El Paso , TX: Scholarly Publishers, 2002. Sives, Amanda. “The Historical Roots of

Awareness of Deaf Sign Language and Gang Signs.

Science.gov (United States)

Smith, Cynthia; Morgan, Robert L.

There have been increasing incidents of innocent people who use American Sign Language (ASL) or another form of sign language being victimized by gang violence due to misinterpretation of ASL hand formations. ASL is familiar to learners with a variety of disabilities, particularly those in the deaf community. The problem is that gang members have…

Gang Youth, Substance Use Patterns, and Drug Normalization

Science.gov (United States)

Sanders, Bill

2012-01-01

Gang membership is an indicator of chronic illicit substance use and such patterns of use may have a normalized character. Using epidemiological and qualitative data collected between 2006 and 2007, this manuscript examines the drug normalization thesis among a small sample (n=60) of gang youth aged 16-25 years from Los Angeles. Overall, while…

The Effects of Army and Air Force Institutional Theories of Victory on Operation Desert Storm

Science.gov (United States)

2015-06-01

an institutional theory of victory.22 The categorization of rules, norms, and culture is somewhat artificial, but it remains useful for examining...rationality that constitutes an institutional theory of victory using the framework provided by Martel above. Chapter 3 seeks to create an argument...practical action,” but for the purposes of military institutions, this thesis refers to this concept as a theory of victory.125 The institutional

Monitoring ARC services with GangliARC

International Nuclear Information System (INIS)

Cameron, D; Karpenko, D

2012-01-01

Monitoring of Grid services is essential to provide a smooth experience for users and provide fast and easy to understand diagnostics for administrators running the services. GangliARC makes use of the widely-used Ganglia monitoring tool to present web-based graphical metrics of the ARC computing element. These include statistics of running and finished jobs, data transfer metrics, as well as showing the availability of the computing element and hardware information such as free disk space left in the ARC cache. Ganglia presents metrics as graphs of the value of the metric over time and shows an easily-digestable summary of how the system is performing, and enables quick and easy diagnosis of common problems. This paper describes how GangliARC works and shows numerous examples of how the generated data can quickly be used by an administrator to investigate problems. It also presents possibilities of combining GangliARC with other commonly-used monitoring tools such as Nagios to easily integrate ARC monitoring into the regular monitoring infrastructure of any site or computing centre.

Gangs, clubs, and alcohol: The effect of organizational membership on adolescent drinking behavior.

Science.gov (United States)

Suh, Chan S; Brashears, Matthew E; Genkin, Michael

2016-07-01

How does adolescent organizational membership in general, and simultaneous membership in distinct types of organizations in particular, impact drinking behavior? While past studies have focused either on the learning effect of involvement with gangs or on the constraining influence of conventional organizations on adolescent problem behavior, we explore the possibility that conventional school clubs can serve as socializing opportunities for existing gang members to engage in drinking behavior with non-gang club members. Using the Add Health data, we show that gang members drink more often, and engage in more binge drinking, than non-members. More importantly, individuals who are members of both gangs and school clubs drink alcohol at greater levels than those who are solely involved in gangs. In addition, non-gang adolescents who are co-members with gang members in the same school club are more likely to drink alcohol than non-members. This result has important implications for understanding the role of organizations in adolescent behavior and suggests that the study of delinquent behaviors would benefit from devoting more attention to individuals who bridge distinct types of organizations. Copyright © 2016 Elsevier Inc. All rights reserved.

Working With Chinese Triad Youth Gangs: Correct Diagnosis and Strategic Intervention.

Science.gov (United States)

Lo, T Wing; Tam, H L

2018-02-01

Across the world, youth workers have been active in helping vulnerable youth groups. In Hong Kong, government-funded youth services are conducted by professional social workers to help vulnerable youths. This article adopted a case study approach to investigate a youth group who committed a murder. Nine murderers and two social workers were interviewed. It aims to uncover the structure and activities of the group and analyse the gang intervention prior to the murder to find out what had gone wrong and identify the lessons that social workers can learn from the murder. Four misconceptions in gang intervention have been identified. First, because of the Triad (Chinese-organised crime) affiliation, this is not just a group of deviant youths but a youth gang. Second, because it is a gang, the social workers should not group them but should instead degroup them to avoid contamination. Third, diagnosis is different from labelling. With the right diagnosis, services can be tailor-made to delabel them. Fourth, when the youths are diagnosed as a gang, outreach work instead of centre work should be provided-social workers should reach out to the gangland to uncover the youths' gang participation and crime involvement.

Delinquency Among Members of Hong Kong Youth Street Gangs: The Role of the Organizational Structures of Gangs and Triad Affiliations.

Science.gov (United States)

Chui, Wing Hong; Khiatani, Paul Vinod

2018-07-01

This study explores the importance of organizational structures and formal affiliations with the Hong Kong triads to delinquency among youth street gang members in Hong Kong. More specifically, this study examines the relative importance of the number of organizational structures and triad affiliation to patterns of delinquency in a sample of active members of youth street gangs ( N = 201). With the aid of outreach social workers, a convenience sampling method was used to recruit a gender-balanced sample of at-risk youths. Logistic regression analysis of the survey data that was gathered indicated that formal affiliation to Hong Kong triads and the presence of organizational structures significantly increased the odds of delinquency (independently of each other). Suggestions for future research on gang membership and delinquency, with particular reference to the Asian context, are provided.

Hurtigt i gang

DEFF Research Database (Denmark)

Krogh Graversen, Brian; Damgaard, Bodil; Rosdahl, Anders

hurtigere i job. Det gjaldt for alle grupper af ledige, men effekten var særlig stor for akademikere. Tilsyneladende har mange stærke ledige hurtigt selv fundet et job, for at undgå at deltage i aktiviteterne under den intensive indsats. Svagere ledige synes derimod at være blevet hjulpet i gang af...

Specters of War in Pyongyang: The Victorious Fatherland Liberation War Museum in North Korea

OpenAIRE

Suzy Kim

2015-01-01

While North Korea accused South Korea of starting a “civil war” (naeran) during the Korean War, it has now moved away from such depictions to paint the war as an American war of imperialist aggression against Korea that was victoriously thwarted under the leadership of Kim Il Sung. In this regard, it may be more than a coincidence that the Victorious Fatherland Liberation War Museum in Pyongyang was built in the early 1970s, just as the Vietnam War drew to a close with a Vietnamese victory. T...

Gang Membership and Drug Involvement: Untangling the Complex Relationship

Science.gov (United States)

Bjerregaard, Beth

2010-01-01

Previous research has consistently demonstrated a relationship between gang membership and involvement in illegal substances. In addition, researchers have noted that gang members are frequently more heavily involved in drug sales, which often lead to increases in violent behaviors. Most of this research, however, is either cross-sectional or…

Physics analysis of the gang partial rod drive event

International Nuclear Information System (INIS)

Boman, C.; Frost, R.L.

1992-08-01

During the routine positioning of partial-length control rods in Gang 3 on the afternoon of Monday, July 27, 1992, the partial-length rods continued to drive into the reactor even after the operator released the controlling toggle switch. In response to this occurrence, the Safety Analysis and Engineering Services Group (SAEG) requested that the Applied Physics Group (APG) analyze the gang partial rod drive event. Although similar accident scenarios were considered in analysis for Chapter 15 of the Safety Analysis Report (SAR), APG and SAEG conferred and agreed that this particular type of gang partial-length rod motion event was not included in the SAR. This report details this analysis

Transition I efficiency and victory in volleyball matches

Directory of Open Access Journals (Sweden)

Herbert Ugrinowitsch

2014-03-01

Full Text Available The present study investigated the correlation between Transition Iwith victory in volleyball matches. The 2002 South-American Youth Men's Championship was recorded and the Transition I was analyzed and classified as negative, null or positive. Results of the efficiency in Transition I was calculated using t test for independent samples and compared to the efficiency between teams during each set and matches. Spearman correlation assessed the relationship between efficiency in each set and results of the matches with the final ranking in the championship. The results showed that the winning teams exhibited higher efficiency in Transition I, as well as a positive relationship of higher efficiency in Transition I with all of their results. The higher efficiency in Transition I is related to victory in volleyball matches.

Community-based gang desistance

DEFF Research Database (Denmark)

Højgaard Dichmann, Kirstine; Jensen, Tobias Bo; Mørck, Line Lerche

2018-01-01

of belonging to the communities in Homeboy Industries also facilitates self-reflection and identity transformation. Homeboy Industries is furthermore an important life changing resource because it offers former gang members a legal source of income. This provides them with a new and secure base, a way...

Gangs, Migration and Crime; The changing landscape in Europe and the United States

NARCIS (Netherlands)

Decker, S.; van Gemert, F.H.M.; Pyrooz, D.C.

2009-01-01

The history of gangs is intertwined with migration. In America, a number of classic studies have reported on the possible causal link between immigration, socio-economic position, social disorganization, and gang formation. More recently in Europe, the impact of migration on gangs reflects a complex

An integrated public health and criminal justice approach to gangs: What can research tell us?

Directory of Open Access Journals (Sweden)

Erika Gebo

2016-12-01

Full Text Available There has been a call to better link public health and criminal justice approaches to best address crime problems generally, and youth and gang violence in particular. Importantly, there has yet to be a systematic examination of how criminal justice approaches can be integrated within a public health framework. This paper examines the strengths and challenges with mapping gang research and evidence-informed practices onto a public health approach. Conceptual examination reveals benefits to utilizing an integrated framework, but it also exposes core problems with identification and prediction of gang joining and gang membership. The gang label as a master status is called into question. It is argued that a public health framework can inform public policy approaches as to when the focus should be youth violence versus gangs and gang violence.

Prevalence of Clonorchis sinensis Metacercariae in Fish from Water Systems of Seomjin-gang (River).

Science.gov (United States)

Sohn, Woon-Mok; Na, Byoung-Kuk; Cho, Shin-Hyeong; Park, Mi-Yeoun; Kim, Cheon-Hyeon; Hwang, Min-Ah; No, Kyeong-Woo; Yoon, Ki-Bok; Lim, Hyun-Cheol

2017-06-01

The prevalence of Clonorchis sinensis metacercariae ( Cs Mc) was examined in freshwater fish from the water systems of Seomjin-gang (River), the Republic of Korea. Total 1,604 fish from 7 local sites of Seomjin-gang were examined by artificial digestion methods. The metacercariae of C. sinensis were detected in 102 (39.8%) out of 256 fish (14 species) from the upper reaches of Seomjin-gang, i.e., Osucheon (22.3% in 6 fish species) in Imsil-gun, and Seomjin-gang (63.9% in 9 fish species) in Sunchang-gun, Jeollabuk-do. Their average density was 9.0 per infected fish. They were also found in 132 (48.0%) out of 275 fish (12 spp.) from the middle reaches of Seomjin-gang, i.e., Songdaecheon (58.9% in 4 fish species) in Namwon-si, Jeollabuk-do, and Seomjin-gang (45.2% in 10 fish species) in Gokseong-gun, Jeollanam-do. Their average density was 21.0 per infected fish. Cs Mc were detected in 77 (56.6%) out of 136 fish (11 species) from the lower reaches of Seomjin-gang, i.e., Seomjin-gang (73.3% in 11 fish species) in Gurye-gun, Jeollanam-do, and Namsancheon (8.6% in 1 fish species) in Hadong-gun, Gyeongsangnam-do. Their average density was 64.9 per infected fish. The metacercariae of Metorchis orientalis were also detected in 6 fish species from 4 sites of Seomjin-gang. Conclusively, it has been confirmed that Cs Mc are more or less prevalent in fish from some water systems of Seomjin-gang in Korea.

Adolescents, gangs, and perceptions of safety, parental engagement, and peer pressure.

Science.gov (United States)

Kelly, Sarah E; Anderson, Debra G

2012-10-01

Adolescents are exposed to various forms of gang violence, and such exposure has led them to feel unsafe in their neighborhood and have differing interactions with their parents and peers. This qualitative study explored adolescents', parents', and community center employees' perceptions of adolescents' interaction with their neighborhood, family, and peers. Three themes emerged from the data: Most adolescents reported that the community center provided a safe environment for them; parental engagement influenced adolescents' experiences with gangs; and adolescents were subjected to peer pressure in order to belong. Exposure to gang violence can leave an impression on adolescents and affect their mental health, but neighborhood safety and relationships with parents and peers can influence adolescents' exposure to gang violence. Recommendations regarding the use of health care professionals at community centers are proposed. Copyright 2012, SLACK Incorporated.

Geographical influences of an emerging network of gang rivalries

Science.gov (United States)

Hegemann, Rachel A.; Smith, Laura M.; Barbaro, Alethea B. T.; Bertozzi, Andrea L.; Reid, Shannon E.; Tita, George E.

2011-10-01

We propose an agent-based model to simulate the creation of street gang rivalries. The movement dynamics of agents are coupled to an evolving network of gang rivalries, which is determined by previous interactions among agents in the system. Basic gang data, geographic information, and behavioral dynamics suggested by the criminology literature are integrated into the model. The major highways, rivers, and the locations of gangs’ centers of activity influence the agents’ motion. We use a policing division of the Los Angeles Police Department as a case study to test our model. We apply common metrics from graph theory to analyze our model, comparing networks produced by our simulations and an instance of a Geographical Threshold Graph to the existing network from the criminology literature.

Reconsidering Hispanic Gang Membership and Acculturation in a Multivariate Context

Science.gov (United States)

Miller, Holly Ventura; Barnes, J. C.; Hartley, Richard D.

2011-01-01

Previous qualitative research has suggested that Hispanic gang membership is linked to the process of acculturation. Specifically, studies have indicated that those who are less assimilated into mainstream American or "Anglo" society are at greater risk for joining gangs. Building on these observations, this study examines the relationship between…

Gang membership and marijuana use among African American female adolescents in North Carolina

Directory of Open Access Journals (Sweden)

Wechsberg WM

2015-11-01

Full Text Available Wendee M Wechsberg,1–4 Irene A Doherty,1 Felicia A Browne,1,5 Tracy L Kline,1 Monique G Carry,6 Jerris L Raiford,6 Jeffrey H Herbst6 1Substance Abuse Treatment Evaluations and Interventions Research Program, RTI International, Research Triangle Park, 2Gillings Global School of Public Health, University of North Carolina, Chapel Hill, 3Psychology in the Public Interest, North Carolina State University, Raleigh, 4Psychiatry and Behavioral Sciences, School of Medicine, Duke University, Durham, NC, 5Department of Social and Behavioral Sciences, Harvard School of Public Health, Boston, MA, 6Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention, US Centers for Disease Control and Prevention, Atlanta, GA, USA Abstract: The southeastern US sustains the highest high school dropout rates, and gangs persist in underserved communities. African American female adolescents who drop out of school and are gang members are at substantial risk of exposure to severe violence, physical abuse, and sexual exploitation. In this study of 237 female African American adolescents 16–19 years of age from North Carolina who dropped out or considered dropping out, 11% were current or past gang members. Adolescents who reported gang membership began smoking marijuana at a mean age of 13, whereas those who reported no gang membership began at a mean age of 15 years (P<0.001. The mean ages of first alcohol use were 14 years and 15 years for gang members and non-gang members, respectively (P=0.04. Problem alcohol use was high in both groups: 40% and 65% for non-gang and gang members, respectively (P=0.02. Controlling for frequent marijuana use and problem alcohol use, adolescents who reported gang membership were more likely than non-gang members to experience sexual abuse (odds ratio [OR] =2.60, 95% confidence interval [CI] [1.06, 6.40], experience physical abuse (OR =7.33, 95% CI [2.90, 18.5], report emotional abuse from

Serious Delinquency and Gang Participation: Combining and Specializing in Drug Selling, Theft and Violence.

Science.gov (United States)

Gordon, Rachel A; Rowe, Hillary L; Pardini, Dustin; Loeber, Rolf; White, Helene Raskin; Farrington, David P

2014-06-01

Using Pittsburgh Youth Study data, we examined the extent to which over 600 gang members and non-gang involved young men specialized in drug selling, serious theft, or serious violence or engaged simultaneously in these serious delinquent behaviors, throughout the 1990s. We found that the increase in delinquency associated with gang membership was concentrated in two combinations: serious violence and drug selling; serious violence, drug selling, and serious theft. Several covariates were similarly associated with multi-type serious delinquency and gang membership (age, historical time, Black race, and residential mobility), suggesting that these behaviors may share common developmental, familial, and contextual risks. We encourage future research to further examine the association of gang membership with engagement in particular configurations of serious delinquency.

Serious Delinquency and Gang Participation: Combining and Specializing in Drug Selling, Theft and Violence

Science.gov (United States)

Gordon, Rachel A.; Rowe, Hillary L.; Pardini, Dustin; Loeber, Rolf; White, Helene Raskin; Farrington, David P.

2014-01-01

Using Pittsburgh Youth Study data, we examined the extent to which over 600 gang members and non-gang involved young men specialized in drug selling, serious theft, or serious violence or engaged simultaneously in these serious delinquent behaviors, throughout the 1990s. We found that the increase in delinquency associated with gang membership was concentrated in two combinations: serious violence and drug selling; serious violence, drug selling, and serious theft. Several covariates were similarly associated with multi-type serious delinquency and gang membership (age, historical time, Black race, and residential mobility), suggesting that these behaviors may share common developmental, familial, and contextual risks. We encourage future research to further examine the association of gang membership with engagement in particular configurations of serious delinquency. PMID:24954999

Associations between school violence, military connection, and gang membership in California secondary schools.

Science.gov (United States)

Estrada, Joey Nuñez; Gilreath, Tamika D; Sanchez, Cathia Y; Astor, Ron Avi

2017-01-01

Recent studies have found that military-connected students confront many challenges-such as secondary traumatization-that may stem from a parent's deployment and frequent relocations. It is possible that multiple moves and deployments of family service members are associated with military-connected students' gang membership and involvement with school violence behaviors. In this study, a total of 13,484 students completed the core and military modules of the California Healthy Kids Survey. Logistic regressions examined the odds of a student being a member of a gang given their grade, gender, race/ethnicity, school violence behaviors, military-connectedness, changes in schools, and familial deployments. Results indicated that of the nearly 8% of students sampled who reported being in a gang, those with a parent or sibling currently serving in the military reported a higher prevalence rate of gang membership than students with no military connection. Students who reported being in fights or carrying weapons to school were at least twice more likely to be a gang member than students who reported not having been in fights or carrying weapons. Changing schools 4 or more times in a 5-year period and experiencing at least 1 familial deployment were also associated with an increased likelihood of gang membership. The findings of this study offer incentive to further explicate the gang and school violence experiences of military-connected students. This study supports schools in understanding the characteristics of the military-connected students and families they serve so they can implement appropriate interventions to curb gang and school violence behaviors. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Murder by structure: dominance relations and the social structure of gang homicide.

Science.gov (United States)

Papachristos, Andrew V

2009-07-01

Most sociological theories consider murder an outcome of the differential distribution of individual, neighborhood, or social characteristics. And while such studies explain variation in aggregate homicide rates, they do not explain the social order of murder, that is, who kills whom, when, where, and for what reason. This article argues that gang murder is best understood not by searching for its individual determinants but by examining the social networks of action and reaction that create it. In short, the social structure of gang murder is defined by the manner in which social networks are constructed and by people's placement in them. The author uses a network approach and incident-level homicide records to recreate and analyze the structure of gang murders in Chicago. Findings demonstrate that individual murders between gangs create an institutionalized network of group conflict, net of any individual's participation or motive. Within this network, murders spread through an epidemic-like process of social contagion as gangs evaluate the highly visible actions of others in their local networks and negotiate dominance considerations that arise during violent incidents.

LA's Gang-Busters--Lessons Learned.

Science.gov (United States)

Harper, Suzanne

1989-01-01

Regarded as the nation's gang violence capital, Los Angeles' politicians and law enforcement and school administrators are using knowledge from lost battles to win the war. Solutions include targeting younger children, teaching self-esteem and communication skills, as well as organizing group graffiti cleanups. (SI)

Persuasive History: A Critical Comparison of Television's "Victory at Sea" and "The World at War."

Science.gov (United States)

Mattheisen, Donald J.

1992-01-01

Discusses the television series "Victory at Sea" and "The World at War" and their use in teaching about World War II. Contrasts that war's glorious portrayal in "Victory at Sea" with the more ambiguous presentation of "The World at War." Suggests that students can learn a great deal about war and film itself…

The role of delinquency, proactive aggression, psychopathy and behavioral school engagement in reported youth gang membership.

Science.gov (United States)

Ang, Rebecca P; Huan, Vivien S; Chan, Wei Teng; Cheong, Siew Ann; Leaw, Jia Ning

2015-06-01

Given the robust positive association between gangs and crime, a better understanding of factors related to reported youth gang membership is critical and especially since youth in gangs are a universal concern. The present study investigated the role of delinquency, proactive aggression, psychopathy and behavioral school engagement in reported youth gang membership using a large sample of 1027 Singapore adolescents. Results from logistic regression showed that delinquency, proactive aggression, and behavioral school engagement were statistically significant risk factors for reported youth gang membership, and that psychopathy was not related to reported gang membership. Implications for prevention and intervention work with respect to youth gang membership were discussed. In particular, strengthening students' engagement with school and meaningful school-related activities and developing supportive teacher-student relationships are particularly important in working with young people with respect to prevention work. Additionally, the present study's theoretical and empirical contributions were also discussed. Copyright © 2015 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Teaching with Documents: Victory Gardens in World War II.

Science.gov (United States)

Baars, Patricia, Ed.

1986-01-01

Covers the Victory Garden campaign of the early 1940s begun by the Office of War Information and the Office of Civil Defense. Provides a facsimile of a poster designed to publicize the program in addition to seven teaching activities. (JDH)

Gang membership and substance use: guilt as a gendered causal pathway.

Science.gov (United States)

Coffman, Donna L; Melde, Chris; Esbensen, Finn-Aage

2015-03-01

We examine whether anticipated guilt for substance use is a gendered mechanism underlying the noted enhancement effect of gang membership on illegal drug use. We also demonstrate a method for making stronger causal inferences when assessing mediation in the presence of moderation and time-varying confounding. We estimate a series of inverse propensity weighted models to obtain unbiased estimates of mediation in the presence of confounding of the exposure (i.e., gang membership) and mediator (i.e., anticipated guilt) using three waves of data from a multi-site panel study of a law-related education program for youth ( N =1,113). The onset of gang membership significantly decreased anticipated substance use guilt among both male and female respondents. This reduction was significantly associated with increased frequency of substance use only for female respondents, however, suggesting that gender moderates the mechanism through which gang membership influences substance use. Criminologists are often concerned with identifying causal pathways for antisocial and/or delinquent behavior, but confounders of the exposure, mediator, and outcome often interfere with efforts to assess mediation. Many new approaches have been proposed for strengthening causal inference for mediation effects. After controlling for confounding using inverse propensity weighting, our results suggest that interventions aimed at reducing substance use by current and former female gang members should focus on the normative aspects of these behaviors.

Uranium removal during low discharge in the Ganges-Brahmaputra mixing zone

International Nuclear Information System (INIS)

Carroll, J.; Moore, W.S.

1993-01-01

The Ganges-Brahmaputra river system supplies more dissolved uranium to the ocean than any other system in the world (Sarin et al., 1990; Sackett et al., 1973). However, there have been no investigations to determine whether riverine supplies of uranium are altered by geochemical reactions in the river-ocean mixing zone. In this study, uranium and salinity data were collected in the Ganges-Brahmaputra mixing zone during a period of low river discharge. The uranium distribution with salinity shows that in waters <12 ppt salinity, uranium activities are significantly lower than predicted from conservative mixing of river and seawater. This suggests that uranium is being removed within the mixing zone. The behavior of uranium in the Ganges-Brahmaputra is in sharp contrast to its behavior in the Amazon mixing zone where McKee et al. (1978) found uranium activities significantly higher than predicted from conservative mixing. The contrasting behaviors for uranium in these systems are due to the different locations where mixing between river and seawater occurs. For the Amazon, mixing takes place on the continental shelf whereas for the Ganges-Brahmaputra, mixing occurs within shoreline sedimentary environments. The physiochemical processes controlling uranium removal to sediment deposits in the Amazon are partly known. The authors discuss mechanisms which may be removing uranium to suspended and mangrove sediments in the Ganges-Brahmaputra

Gang membership of California middle school students: behaviors and attitudes as mediators of school violence.

Science.gov (United States)

Estrada, Joey Nuñez; Gilreath, Tamika D; Astor, Ron Avi; Benbenishty, Rami

2013-08-01

Empirical evidence examining how risk and protective behaviors may possibly mediate the association between gang membership and school violence is limited. This study utilizes a statewide representative sample of 152 023 Latino, Black and White seventh graders from California to examine a theoretical model of how school risk (e.g. truancy, school substance use and risky peer approval) and protective (e.g. connectedness, support and safety) behaviors and attitudes mediate the effects of gang membership on school violence behaviors. The dataset was collected in the 2005-2006 and 2006-2007 academic school years using the ongoing large-scale California Healthy Kids Survey conducted by WestEd for the State of California. Approximately 9.5% of the sample considered themselves to be a member of a gang. The findings indicate that school risk behaviors and attitudes mediate the association between gang membership and school violence behaviors. Although the direct negative association between gang membership and school violence perpetration is weak, the positive indirect effect mediated by school risks behaviors and attitudes is strong. This indicates that when gang members engage in school risk behaviors, they are much more likely to be school violence perpetrators. Implications for further research, theory and practice for both gang and school violence researchers are discussed.

BULLYING BEHAVIOUR OF ADOLESCENTS BASED ON GENDER, GANG AND FAMILY

Directory of Open Access Journals (Sweden)

Kadek Ayu Erika

2017-06-01

Full Text Available Introduction: Bullying is a social problem which is part of aggressive violent behaviour done continuously and have negative impact to victims and its subject and happened at school. This study aimed to know the description of knowledge and adolescents behavior about bullying based on their age, gang, and family. Methods: This study used analytic descriptive design with number of sample was 246 adolescents from grade 1, 2, 3 of senior high school which used stratified random sampling. Instruments of this study were knowledge questioner, and modified of The Bullying Prevalence Questionnaire in guttman and likert scale. Data analysis used cross tabulation. Result: Data show that adolescents have a good knowledge (93.9% and less (6.1%. Bullying subjects were 93.9% and victims 94.7%. Forms of verbal bullying indicated the subjects (93.1% and victims (92.3%. Bullying subjects majority occurred in males (94.1% and women become victims (96.3%. Numbers of bullying subjects do not have a gang (94.5%, while those with gang as victims (95.2%. There were five adolescents who live in stepfamilies become subjects and victims of bullying. Conclusion: The majority of adolescents have good knowledge about bullying, bullying form the vast majority were verbal bullying with subjects and victims of bullying who occurs in all classes. The majority of bullying subjects do not have a gang, and as the majority of victims have a gang. Almost all adolescents with different family types become subjects and victims of bullying. Therefore, an intensive educational effort and spiritual needs to be done to change the behavior of adolescents to be adolescents with well character.

Reviving the Ganges Water Machine: potential

Science.gov (United States)

Amarasinghe, Upali Ananda; Muthuwatta, Lal; Surinaidu, Lagudu; Anand, Sumit; Jain, Sharad Kumar

2016-03-01

The Ganges River basin faces severe water challenges related to a mismatch between supply and demand. Although the basin has abundant surface water and groundwater resources, the seasonal monsoon causes a mismatch between supply and demand as well as flooding. Water availability and flood potential is high during the 3-4 months (June-September) of the monsoon season. Yet, the highest demands occur during the 8-9 months (October-May) of the non-monsoon period. Addressing this mismatch, which is likely to increase with increasing demand, requires substantial additional storage for both flood reduction and improvements in water supply. Due to hydrogeological, environmental, and social constraints, expansion of surface storage in the Ganges River basin is problematic. A range of interventions that focus more on the use of subsurface storage (SSS), and on the acceleration of surface-subsurface water exchange, has long been known as the Ganges Water Machine (GWM). The approach of the GWM for providing such SSS is through additional pumping and depleting of the groundwater resources prior to the onset of the monsoon season and recharging the SSS through monsoon surface runoff. An important condition for creating such SSS is the degree of unmet water demand. The paper shows that the potential unmet water demand ranging from 59 to 124 Bm3 year-1 exists under two different irrigation water use scenarios: (i) to increase irrigation in the Rabi (November-March) and hot weather (April-May) seasons in India, and the Aman (July-November) and Boro (December-May) seasons in Bangladesh, to the entire irrigable area, and (ii) to provide irrigation to Rabi and the hot weather season in India and the Aman and Boro seasons in Bangladesh to the entire cropped area. However, the potential for realizing the unmet irrigation demand is high only in 7 sub-basins in the northern and eastern parts, is moderate to low in 11 sub-basins in the middle, and has little or no potential in 4 sub

Gang Involvement among Immigrant and Refugee Youth: A Developmental Ecological Systems Approach

Science.gov (United States)

Goodrum, Nada M.; Chan, Wing Yi; Latzman, Robert D.

2015-01-01

Immigrant and refugee youth are at elevated risk for joining gangs, which, in turn, is associated with a host of maladaptive outcomes. Previous literature on risk and protective factors for immigrant and refugee youth gang involvement has been inconclusive. Applying a developmental ecological systems approach, this study investigated contextual…

Commanders of the Great Victory

Directory of Open Access Journals (Sweden)

Anatoly Dmitriyevich Borshchov

2015-01-01

Full Text Available The honorary title of «commander» as well as the «admiral» is granted to a military or naval figure on the basis of public recognition of his personal contribution to the success of actions. Generals are usually individuals with creative thinking, the ability to foresee the development of military events. Generals usually have such personality traits as a strong will and determination, rich combat experience, credibility and high organizational skills. In an article dedicated to the 70th anniversary of the Soviet victory in the Great War examines the experience of formation and practice of the most talent-ed Soviet military leaders.

Any of them will do: In-group identification, out-group entitativity, and gang membership as predictors of group-based retribution.

Science.gov (United States)

Vasquez, Eduardo A; Wenborne, Lisa; Peers, Madeline; Alleyne, Emma; Ellis, Kirsty

2015-05-01

In non-gang populations, the degree of identification with an in-group and perceptions of out-group entitativity, the perception of an out-group as bonded or unified, are important contributors to group-based aggression or vicarious retribution. The link between these factors and group-based aggression, however, has not been examined in the context of street gangs. The current study assessed the relationship among in-group identification, perceptions of out-group entitativity, and the willingness to retaliate against members of rival groups who did not themselves attack the in-group among juvenile gang and non-gang members in London. Our results showed the predicted membership (gang/non-gang) × in-group identification × entitativity interaction. Decomposition of the three-way interaction by membership revealed a significant identification × entitativity interaction for gang, but not for non-gang members. More specifically, gang members who identify more strongly with their gang and perceived a rival group as high on entitativity were more willing to retaliate against any of them. In addition, entitativity was a significant predictor of group-based aggression after controlling for gender, in-group identification, and gang membership. Our results are consistent with socio-psychological theories of group-based aggression and support the proposal that such theories are applicable for understanding gang-related violence. Aggr. Behav. 41:242-252, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

The Interpersonal Metafunction Analysis of Barack Obama's Victory Speech

Science.gov (United States)

Ye, Ruijuan

2010-01-01

This paper carries on a tentative interpersonal metafunction analysis of Barack Obama's victory speech from the interpersonal metafunction, which aims to help readers understand and evaluate the speech regarding its suitability, thus to provide some guidance for readers to make better speeches. This study has promising implications for speeches as…

The Impact of Location Alteration on School Attendance of Chicano Gang Members.

Science.gov (United States)

Hunsaker, Alan C.

The study examined whether a change in school site affected the school attendance of 13 male Chicano gang members, 13 to 18 years of age, admitted to a community-based delinquency and gang violence prevention project. Since an active Alternative Studies Program, designed for students with special learning problems or for working students, already…

"Dark Victory" (prognosis negative): The beginnings of neurology on screen.

Science.gov (United States)

Wijdicks, Eelco F M

2016-04-12

In "Dark Victory," released in theaters in 1939, the diagnosis and management of a progressive brain tumor was a central part of the screenplay, and this film marked the beginnings of the depiction of neurologic disease in cinema. Bette Davis' cinematic portrayal of a young woman dying from a brain tumor is close to the reality of denial, bargaining, a hope for a cure, and final acceptance. "Dark Victory" includes part of a neurologic examination (funduscopy, testing of strength, testing of stereognosis, and tendon reflexes). The film also alludes to decisions on what to tell the patient (better say nothing) and shows an implausible clinical course (an abrupt peaceful ending). The film is unusual in depicting the presentation of a brain tumor, but the cinematic portrayal of the vicissitudes of living with a brain tumor is often close to reality. © 2016 American Academy of Neurology.

Increased incidence of gang rape in Benin-City, Nigeria: Is this a ...

African Journals Online (AJOL)

Increased incidence of gang rape in Benin-City, Nigeria: Is this a forensic epidemic? ... creates so much negative impact on the legal outcome. There is a need to provide a holistic support to the victims and to review Nigerian laws on sexual offences for the good of all. Keywords: Gang-Rape, Sexual violence, Forensic, Ep ...

The Victory Disease and the US Army After the Cold War

National Research Council Canada - National Science Library

Allen, John

1999-01-01

This study investigates the US Army after the end of the Cold War, specifically how the "Victory Disease" resulting from winning the Cold War caused a complacency in the US Army which eventually led...

Individual and Familial Characteristics of Youths Involved in Street Corner Gangs in Singapore.

Science.gov (United States)

Kee, C.; Sim, K.; Teoh, J.; Tian, C. S.; Ng, K. H.

2003-01-01

Study compares 36 youths involved in street corner gangs in Singapore with 91 age-matched controls on measures of self-esteem, aggression, dysfunctional parenting and parent-adolescent communication. Results revealed that gang youths had lower self-esteem and higher levels of aggression than controls. Findings diverge from anticipated familial…

Ganges Valley Aerosol Experiment: Science and Operations Plan

Energy Technology Data Exchange (ETDEWEB)

Kotamarthi, VR

2010-06-21

The Ganges Valley region is one of the largest and most rapidly developing sections of the Indian subcontinent. The Ganges River, which provides the region with water needed for sustaining life, is fed primarily by snow and rainfall associated with Indian summer monsoons. Impacts of changes in precipitation patterns, temperature, and the flow of the snow-fed rivers can be immense. Recent satellite-based measurements have indicated that the upper Ganges Valley has some of the highest persistently observed aerosol optical depth values. The aerosol layer covers a vast region, extending across the Indo-Gangetic Plain to the Bay of Bengal during the winter and early spring of each year. The persistent winter fog in the region is already a cause of much concern, and several studies have been proposed to understand the economic, scientific, and societal dimensions of this problem. During the INDian Ocean EXperiment (INDOEX) field studies, aerosols from this region were shown to affect cloud formation and monsoon activity over the Indian Ocean. This is one of the few regions showing a trend toward increasing surface dimming and enhanced mid-tropospheric warming. Increasing air pollution over this region could modify the radiative balance through direct, indirect, and semi-indirect effects associated with aerosols. The consequences of aerosols and associated pollution for surface insolation over the Ganges Valley and monsoons, in particular, are not well understood. The proposed field study is designed for use of (1) the ARM Mobile Facility (AMF) to measure relevant radiative, cloud, convection, and aerosol optical characteristics over mainland India during an extended period of 9–12 months and (2) the G-1 aircraft and surface sites to measure relevant aerosol chemical, physical, and optical characteristics in the Ganges Valley during a period of 6–12 weeks. The aerosols in this region have complex sources, including burning of coal, biomass, and biofuels; automobile

Racism, Schooling, and the Streets: A Critical Analysis of Vietnamese American Youth Gang Formation in Southern California

Directory of Open Access Journals (Sweden)

Kevin D. Lam

2012-01-01

Full Text Available This paper is an analysis of the relationship between educational experiences, street life, and gang formation for Vietnamese American youth gang members in Southern California. I use critical narrative methodology to center the life and experiences of a Los Angeles area gang member. His narrative substantiates how racism in schools and on the streets works together to impact and inform gang formation. Schools were sites of inter-ethnic conflict and racialized tension, and streets were spaces for contentious interactions with the police. In addition, I place the Vietnamese American youth gang phenomenon in larger historical and political contexts such as California’s anti-youth legislation, representations of Asian American youth, and U.S. geo-politics and imperialism—factors that have serious material and ideological implications and consequences.

Specters of War in Pyongyang: The Victorious Fatherland Liberation War Museum in North Korea

Directory of Open Access Journals (Sweden)

Suzy Kim

2015-03-01

Full Text Available While North Korea accused South Korea of starting a “civil war” (naeran during the Korean War, it has now moved away from such depictions to paint the war as an American war of imperialist aggression against Korea that was victoriously thwarted under the leadership of Kim Il Sung. In this regard, it may be more than a coincidence that the Victorious Fatherland Liberation War Museum in Pyongyang was built in the early 1970s, just as the Vietnam War drew to a close with a Vietnamese victory. This article examines the memorialization of the Korean War in North Korea at two pivotal historical points—the end of the Vietnam War in the 1970s and the end of the Cold War in the 1990s—with a particular focus on contemporary exhibitions at the war museum in Pyongyang. Rather than offering a simple comparison of divergent narratives about the war, the article seeks to illustrate that North Korea’s conception of history and its account of the war are staunchly modernist, with tragic consequences.

Gangkill: An Exploratory Empirical Assessment of Gang Membership, Homicide Offending, and Prison Misconduct

Science.gov (United States)

Drury, Alan J.; DeLisi, Matt

2011-01-01

Extant research indicates that inmates with street gang history are prone for prison misconduct but that inmates convicted of homicide offenses are less likely to be noncompliant. No research has explored the interaction between street gang history and homicide offending. Based on official infraction data from 1,005 inmates selected from the…

Alcohol and Drug Use among Gang Members: Experiences of Adolescents Who Attend School

Science.gov (United States)

Swahn, Monica H.; Bossarte, Robert M.; West, Bethany; Topalli, Volkan

2010-01-01

Background: Problems related to gangs have been noted in large cities and in many schools across the United States. This study examined the patterns of alcohol, drug use, and related exposures among male and female high school students who were gang members. Methods: Analyses were based on the Youth Violence Survey, conducted in 2004, and…

Gangs, Marginalised Youth and Social Capital

Science.gov (United States)

Deuchar, Ross

2009-01-01

Adolescents are routinely demonised by politicians and the media.Ross Deuchar's compelling research into the views of some of the toughest--youths who are growing up in socially deprived urban areas of Glasgow in Scotland--reveals the true facts. They talked to him about their lives, gang culture and territorialiity and he passes on their words…

Cognitive Ability and the Division of Labor in Urban Ghettos: Evidence From Gang Activity in U.S. Data

OpenAIRE

Richard Alan Seals Jr.

2011-01-01

I examine the link between IQ and an individual¡¯s decision to join a gang. Data from the NLSY97 and Project on Human Development in Chicago Neighborhoods (PHDCN) are used to estimate time-to-first gang participation. Results from a variety of models which account for sibling effects, neighborhood effects, and non-cognitive traits indicate low IQ is a robust predictor of gang participation. However, the PHDCN results reveal gang participation is affected by a person¡¯s relative IQ, with respe...

Man-made climatic changes in the Ganges basin

Science.gov (United States)

Adel, Miah M.

2002-06-01

Climate data pertaining to the Ganges basin in Bangladesh were analysed to find any climatic changes in the wake of the upstream water diversion by the Farakka Barrage. Whereas the diversions have been continuing from at least 30 international rivers upstream of Bangladesh, the diversion from the Ganges is the best known and has a wider coverage than all other diversions. The diversion reduced the Ganges' discharge through the delta by about 60% from a pre-diversion average value of 1932 m3 s-1, decreased water availability in flood plains, ponds, canals, and ditches by about 50%, dropped the groundwater table, and caused changes in surface features. It took about 5 years of diversions beyond the test run year of 1975 for the environment to react to set 1981 as the baseline year. During the post-baseline era: (1) heating degree days and cooling degree days were respectively 1.33 and 1.44 times more than their counterparts during the pre-baseline era; (2) the summertime and wintertime average temperatures were respectively 1 °C more and 0.5 °C less than the corresponding values during the pre-baseline era; (3) the mode 32 °C of summertime maximum temperatures was 1 °C higher and occurred 414 times more, and the mode 25 °C of wintertime temperature was 1 °C less and occurred 17 times less than the corresponding quantities during the pre-baseline era; (4) the average value of maximum relative humidity has increased by more than 2% and that of minimum relative humidity has dropped by the same amount; (5) the mode 95% and 70% of maximum and minimum relative humidity values have occurred 1322 times and 84 times more respectively than their pre-baseline counterparts; and (6) the frequency for 100 mm or more rainfall and the monthly average rainfalls have dropped by about 50% and 30% respectively. The solution to the climatic changes lies in the restoration of the virgin Ganges flow, dredging of the Ganges and its distributaries to remove shoals and siltation, and re

Praxis development in relation to gang conflicts in Copenhagen, Denmark

DEFF Research Database (Denmark)

Mørck, Line Lerche; Hussain, Khaled; Møller-Andersen, Camilla

2013-01-01

The primary question addressed in this article is how to understand and produce praxis development in the complex and contentious field of street communities of young marginalized men, an area highlighted almost on a daily basis in the Danish media under headlines with terms such as ‘foreigner...... othering of young minority men since the late 1990s, to other societal changes escalating ‘gang-conflicts’ to ‘gang-war’. The article examines how these changes produce new dynamics, tensions and dimensions of binary thinking, which in turn creates new dilemmas in the everyday lives of the people involved...

A Pyrrhic victory for the opponents

International Nuclear Information System (INIS)

Haag, J.

2000-01-01

This article reviews the situation of renewable energies in Switzerland after a popular vote turned down promotional measures in the year 2000. The situation is analysed and the opinions of various leaders of professional associations and political groups are discussed. Comparisons are made between ideas said to evolve from short-term narrow-mindedness and those developed by more visionary corporations and governments. The effect of the negative outcome of the popular vote on research and development and economic development are discussed. The author expresses his opinion that measures will still have to be taken, thus making the opponents' success more of a Pyrrhic sort of victory

David�s initial Philistine victories according to Josephus

Directory of Open Access Journals (Sweden)

C. T. Begg

1999-08-01

Full Text Available The Bible twice relates, in Samuel 5:17-25/1 Chronicles 14:8-17, David�s initial pair of victories over the Philistines. This essay focuses on a third version of David�s triumphs, i.e. that of Josephus in his Ant 7.70-77, comprising this in detail with its two Biblical parallels (as represented by MT, Codex Vaticanus and the LucianictAntiochene MSS of the LXX, the Targums, and the Vulgate.

Dataset on Investigating the role of onsite learning in the optimisation of craft gang's productivity in the construction industry.

Science.gov (United States)

Ugulu, Rex Asibuodu; Allen, Stephen

2017-12-01

The data presented in this article is an original data on "Investigating the role of onsite learning in the optimisation of craft gang's productivity in the construction industry". This article describes the constraints influencing craft gang's productivity and the influence of onsite learning on the blockwork craft gang's productivity. It also presented the method of data collection, using a semi-structured interview and an observation method to collect data from construction organisations. We provided statistics on the top most important constraints affecting the craft gang's productivity using 3-D Bar charts. In addition, we computed the correlation coefficients and the regression model on the influence of onsite learning on craft gang's productivity using the man-hour as the dependent variable. The relationship between blockwork inputs and cycle numbers was determined at 5% significance level. Finally, we presented data information on the application of the learning curve theory using the unit straight-line model equations and computed the learning rate of the observed craft gang's blockwork repetitive work.

"Deterrability" among Gang and Nongang Juvenile Offenders: Are Gang Members More (or Less) Deterrable than Other Juvenile Offenders?

Science.gov (United States)

Maxson, Cheryl L.; Matsuda, Kristy N.; Hennigan, Karen

2011-01-01

This study investigates the effect of the threat of legal sanctions on intentions to commit three types of offenses with a representative sample of 744 officially adjudicated youth with varying histories of offenses and gang involvement. In a departure from previous research, the authors find small severity effects for property crimes that are not…

Stemming the Growth: Exploring the Risk Factors in Group Membership in Domestic Street Gangs and Foreign Terrorist Organizations

Science.gov (United States)

2015-09-01

attempt to explain gang membership and offending and delinquent behavior. New CVE program developers may be able to use these same theories to help...outcome in question—in this case, gang membership. Gang research scholars have discovered a multitude of risk factors that are statistically linked...and offending and delinquent behavior, including cultural diffusion, differential association, social disorganization and strain theory. CVE program

The effect of urban street gang densities on small area homicide incidence in a large metropolitan county, 1994-2002.

Science.gov (United States)

Robinson, Paul L; Boscardin, W John; George, Sheba M; Teklehaimanot, Senait; Heslin, Kevin C; Bluthenthal, Ricky N

2009-07-01

The presence of street gangs has been hypothesized as influencing overall levels of violence in urban communities through a process of gun-drug diffusion and cross-type homicide. This effect is said to act independently of other known correlates of violence, i.e., neighborhood poverty. To test this hypothesis, we independently assessed the impact of population exposure to local street gang densities on 8-year homicide rates in small areas of Los Angeles County, California. Homicide data from the Los Angeles County Coroners Office were analyzed with original field survey data on street gang locations, while controlling for the established covariates of community homicide rates. Bivariate and multivariate regression analyses explicated strong relationships between homicide rates, gang density, race/ethnicity, and socioeconomic structure. Street gang densities alone had cumulative effects on small area homicide rates. Local gang densities, along with high school dropout rates, high unemployment rates, racial and ethnic concentration, and higher population densities, together explained 90% of the variation in local 8-year homicide rates. Several other commonly considered covariates were insignificant in the model. Urban environments with higher densities of street gangs exhibited higher overall homicide rates, independent of other community covariates of homicide. The unique nature of street gang killings and their greater potential to influence future local rates of violence suggests that more direct public health interventions are needed alongside traditional criminal justice mechanisms to combat urban violence and homicides.

Review: Joschka Philipps, Ambivalent Rage: Youth Gangs and Urban Protest in Conakry, Guinea (2013)

OpenAIRE

Ineke van Kessel; Afrika-Studiecentrum Leiden

2014-01-01

Review of the Monograph:Joschka Philipps, Ambivalent Rage: Youth Gangs and Urban Protest in Conakry, Guinea, Paris: L’Harmattan, 2013, ISBN 978-2-343-01577-4, 238 pp. Besprechung der Monographie:Joschka Philipps, Ambivalent Rage: Youth Gangs and Urban Protest in Conakry, Guinea, Paris: L’Harmattan, 2013, ISBN 978-2-343-01577-4, 238 Seiten

[Rape by 2 assaillants and gang rape in Montreal].

Science.gov (United States)

Lamontagne, Y; Boyer, R; Lamontagne, C; Giroux, J

1984-11-01

A survey was conducted in 230 cases of rape and rape attempts heard in the Judicial District of Montreal between January 1975 and May 1978. Data were compiled from the 30 assaults including two or more assaillants. Results show that in cases of rape committed by two men the aggressors are older than gang rapists, meet the victim mainly in her flat or in a bar, and rape her in her own home, in a car or a hotel. In these cases, voyeurism seems to be an important factor since, most of the time, rape is committed by only one of the two aggressors. On the other hand, gang rapists are younger, meet the victim in public places, on the street or when she is hitch-hiking and attack her in one of the aggressors' house, in public places or on the street. Exhibitionism seems more present in this group of rapists. For both groups the victims are mainly single, younger than the aggressors and have diverse occupations. Finally, regarding the legal outcome half of the subjects were liberated or acquitted in both groups. Rape committed by two men had never been studied or compared with gang rape up until now. Results of this survey show dynamic and demographic differences between these two groups of sexual delinquents.

Gangs of Chicago: Perceptions of crime and its effect on the recreation behavior of Latino residents in urban communities

Science.gov (United States)

Monika Stodolska; Juan Carlos Acevedo; Kimberly J. Shinew

2009-01-01

Perception of safety is an important factor affecting the leisure behavior of Latinos residing in urban neighborhoods. Yet research on how fear of crime and fear of gangs in particular affect leisure of ethnic and racial minorities is underdeveloped. The objectives of this study are to examine how gangs operate in recreation spaces in Latino neighborhoods, how gangs...

THE PATH AND PROMISE OF FATHERHOOD FOR GANG MEMBERS

Science.gov (United States)

Moloney, Molly; MacKenzie, Kathleen; Hunt, Geoffrey; Joe-Laidler, Karen

2009-01-01

While an increase in research on criminal desistance has occurred in recent years, little research has been applied to the gang field. Using qualitative interview data, this article examines fatherhood as a potential turning point in the lives of 91 gang members in the San Francisco Bay Area. Fatherhood initiated important subjective and affective transformations that led to changes in outlook, priorities and future orientation. However, these subjective changes were not sufficient unless accompanied by two additional features: first, changes in the amount of time spent on the streets and, second, an ability to support oneself or one’s family with legal income. Though fatherhood is no panacea, becoming a father did act as an important turning point toward desistance and motivator for change for some. PMID:20046970

Raising Barriers to 'Outlaw Motorcycle Gang-Related Events' : Underlining the Difference between Pre-Emption and Prevention

NARCIS (Netherlands)

T. van Ruitenburg (Teun)

2017-01-01

textabstractFighting outlaw motorcycle gangs is currently one of the top priorities of many governments around the world. This is due to the notion that outlaw motorcycle gangs do not consist solely of motorcycle enthusiasts. Numerous cases reveal that these clubs, or at least their members, are

Brief Report: Do Delinquency and Community Violence Exposure Explain Internalizing Problems in Early Adolescent Gang Members?

Science.gov (United States)

Madan, Anjana; Mrug, Sylvie; Windle, Michael

2011-01-01

Adolescent gang members are at higher risk for internalizing problems as well as exposure to community violence and delinquency. This study examined whether gang membership in early adolescence is associated with internalizing problems (depression, anxiety, and suicidal behavior) and whether these associations are mediated by delinquency and…

Gender Norms and Age-Disparate Sexual Relationships as Predictors of Intimate Partner Violence, Sexual Violence, and Risky Sex among Adolescent Gang Members.

Science.gov (United States)

Nydegger, Liesl A; DiFranceisco, Wayne; Quinn, Katherine; Dickson-Gomez, Julia

2017-04-01

Unequal gender norms and age-disparate sexual relationships can lead to power imbalances and are also associated with intimate partner violence (IPV), sexual coercion and violence, and sexual risk behaviors. The present study examined these variables from both victim and perpetrator perspectives among adolescent gang members. Age-disparate sexual relationships were defined as sex partners 5 or more years older among female participants and 5 or more years younger among male participants. Participants were recruited from a mid-sized Midwestern city and completed a 60-90-min audio computer-assisted self-interview in a community-based setting. Participants in this study included 107 female gang members (68 % African-American, 19 % Latina; mean age, 17.6) and 169 male gang members (62 % African-American, 28 % Latino; mean age, 17.7). As hypothesized, endorsing unequal gender norms toward women was significantly related to IPV victimization among female participants and perpetration among male participants, and engagement in group sex in the past month among both female and male participants (ps sexual relationships were significantly more likely to have experienced more IPV and report being raped and males gang members who had age-disparate sexual relationships were significantly more likely to perpetrate IPV in the past year and perpetrate rape (ps sexual relationships were also significantly related to being gang raped among female gang members and participating in a gang rape among male gang members, and engaging in group sex among both female and male gang members (ps sexual relationships were more likely to have been pregnant (ps sexual coercion/violence. Early intervention will also be necessary as these adolescent gang members are already engaged in extremely high-risk, coercive, and violent behaviors.

Justas, fiestas y protagonismos: Alegrías y placeres en El Victorial de Gutierre Díaz de Games = Jousting, Festivities and Prominence: Joy and Pleasures in Gutierre Díaz de Games’s El Victorial

Directory of Open Access Journals (Sweden)

María del Pilar Rábade Obradó

2016-06-01

Full Text Available Este trabajo pretende analizar cómo se reflejan dos emociones básicas, la alegría y el placer, en una crónica del siglo XV, concretamente El Victorial de Gutierre Díaz de Games. Como se trata de una biografía caballeresca, en sus páginas se plasma una visión particular de las dos citadas emociones. Así, la crónica ofrece un elenco de aquellas circunstancias en las que se suponía que los caballeros estaban en situación de experimentar el placer y la alegría. Esas circunstancias van desde las fiestas cortesanas hasta las victorias en batallas, sin olvidar el amor y la amistad.The purpose of this article is to analyze how two basic emotions like joy and pleasure were expressed in a fifteenth-century chronicle, namely El Victorial by Gutierre Díaz de Games. Since the chronicle is a chivalric biography, its pages highlight a particular vision of joy and pleasure. Consequently, the chronicle offers a variety of circumstances in which knights were meant to experience pleasure and happiness. These circumstances range from court festivities to victories in battles, as well as those involving love and friendship.

Evaluation and Evolution of the Gang Resistance Education and Training (G.R.E.A.T.) Program

Science.gov (United States)

Esbensen, Finn-Aage; Peterson, Dana; Taylor, Terrance J.; Freng, Adrienne; Osgood, D. Wayne; Carson, Dena C.; Matsuda, Kristy N.

2011-01-01

The Gang Resistance Education and Training (G.R.E.A.T.) program is a gang- and delinquency-prevention program delivered by law enforcement officers within a school setting. Originally designed in 1991 by Phoenix-area law enforcement agencies to address local needs, the program quickly spread across the United States. In this article, we describe…

The Ganges and the GAP: An Assessment of Efforts to Clean a Sacred River

Directory of Open Access Journals (Sweden)

Kenneth R. Tamminga

2012-07-01

Full Text Available For centuries, the Ganges River in India has been the locus of sacred rites for the Hindus. The religious significance of the Ganges is physically manifested in ghats (stepped landings that form the land-water interface. Besides serving as a site for religious bathing and cremation, the ghats are also tied to people’s livelihoods and are an inseparable part of their daily lives. Today, the increasingly urbanized Ganges basin sustains more than 40 percent of India’s population. At the same time, industrialization and the pressures of a growing population along its banks have contributed to alarming levels of pollution in the river. In 1985, the federal government of India launched the Ganga Action Plan (GAP with the primary objective of cleaning the river. However, characterized by centralized planning and control with little public participation, the GAP had limited impact. In 2011, the government launched yet another clean up program—the National Ganga River Basin Project—with support from the World Bank. In this paper, we take a closer look at the programs to highlight the tenuous relationship between the need for ‘efficient’ management of environmental problems and public participation. Can public participation fit into the technocratic model that is often adopted by environmental programs? What approaches to participation kindle authorship and empowerment among those who share a deep relationship with the river and the ghats? Can religious practices be accommodated within scientific frameworks of adaptive management and resilience? We argue that rethinking the relationship between pollution control programs and participation is crucial for any effort to clean the Ganges, restore its waterfront, and catalyze broader regeneration in the Ganges basin.

Gang Membership, School Violence, and the Mediating Effects of Risk and Protective Behaviors in California High Schools

Science.gov (United States)

Estrada, Joey Nuñez, Jr.; Gilreath, Tamika D.; Astor, Ron Avi; Benbenishty, Rami

2014-01-01

There is insufficient empirical evidence exploring associations between gang membership and school violence behaviors. Using a sample of 272,863 high school students, this study employs a structural equation model to examine how school risk and protective behaviors and attitudes mediate effects of gang members' involvement with school violence…

Gangs in Catalonia. The approach from the Catalonia Government Police Troopers

Directory of Open Access Journals (Sweden)

Santiago Herrero Blanco

2014-05-01

Full Text Available In 2002, the presence of gangs was detected in Catalonia. The groups had their origins in bands from the American continent, with whom they maintained communication and dependency relationships. Since then, there has been steady increase both in the number of gangs and youth involved in them, as well as the level of criminal activity linked to these groups. The police corps have followed the evolution of these groups closely, although the social context is radically different and the levels of crime and violence are not comparable to the other side of the Atlantic. This article seeks to explain the Catalonia Government Troopers’ approach to this phenomenon during this time.DOI: http://dx.doi.org/10.5377/rpsp.v1i2.1360

Surviving gangs, violence and racism in cape town

DEFF Research Database (Denmark)

Lindegaard, Marie Rosenkrantz

Surviving Gangs, Violence and Racism in Cape Town offers an ethnographic study of young men in Cape Town and considers how they stay safe in when growing up in post-apartheid South Africa. Breaking away from previous studies looking at structural inequality and differences, this unique book focus...... they move between "black" or "coloured" township areas and the "white" suburbs of Cape Town....

Dual Trajectories of Gang Affiliation and Delinquent Peer Association during Adolescence: An Examination of Long-Term Offending Outcomes

Science.gov (United States)

Krohn, Marvin D.

2018-01-01

Prior research has demonstrated that both adolescent gang affiliation and perceived delinquent peer association are important predictors of individual offending. A crucial question is whether and how youth gang affiliation contributes to a spectrum of criminal acts above and beyond the influence of associating with delinquent peers. Using 14 waves of data from the Rochester Youth Developmental Study, an ongoing longitudinal panel study aimed at understanding the causes and consequences of delinquency and drug use in an urban sample of adolescents, the current study employs a relatively new modeling technique—dual trajectory analysis—to illustrate the dynamic relationship between these two measures among 666 male youth. The results suggest that the two measures, while overlapping, may constitute distinct concepts that operate in different ways. The most convincing evidence of gang effects, above and beyond the influence of perceived peer delinquency, is for violent behavior and by extension police arrest. Our findings contribute to developmental research and provide information that informs future gang control efforts. PMID:26748922

Modular open RF architecture: extending VICTORY to RF systems

Science.gov (United States)

Melber, Adam; Dirner, Jason; Johnson, Michael

2015-05-01

Radio frequency products spanning multiple functions have become increasingly critical to the warfighter. Military use of the electromagnetic spectrum now includes communications, electronic warfare (EW), intelligence, and mission command systems. Due to the urgent needs of counterinsurgency operations, various quick reaction capabilities (QRCs) have been fielded to enhance warfighter capability. Although these QRCs were highly successfully in their respective missions, they were designed independently resulting in significant challenges when integrated on a common platform. This paper discusses how the Modular Open RF Architecture (MORA) addresses these challenges by defining an open architecture for multifunction missions that decomposes monolithic radio systems into high-level components with welldefined functions and interfaces. The functional decomposition maximizes hardware sharing while minimizing added complexity and cost due to modularization. MORA achieves significant size, weight and power (SWaP) savings by allowing hardware such as power amplifiers and antennas to be shared across systems. By separating signal conditioning from the processing that implements the actual radio application, MORA exposes previously inaccessible architecture points, providing system integrators with the flexibility to insert third-party capabilities to address technical challenges and emerging requirements. MORA leverages the Vehicular Integration for Command, Control, Communication, Computers, Intelligence, Surveillance, and Reconnaissance (C4ISR)/EW Interoperability (VICTORY) framework. This paper concludes by discussing how MORA, VICTORY and other standards such as OpenVPX are being leveraged by the U.S. Army Research, Development, and Engineering Command (RDECOM) Communications Electronics Research, Development, and Engineering Center (CERDEC) to define a converged architecture enabling rapid technology insertion, interoperability and reduced SWaP.

Commitment language and homework completion in a behavioral employment program for gang-affiliated youth.

Science.gov (United States)

Smith, Caitlin; Huey, Stanley J; McDaniel, Dawn D

2015-05-01

Research with substance-abusing samples suggests that eliciting commitment language during treatment may improve motivation to change, increase treatment engagement, and promote positive treatment outcomes. However, the relationship between in-session client language and treatment success is not well-understood for youth offender populations. This study evaluated the relationship between commitment language, treatment engagement (i.e., homework completion), and weekly employment outcomes for six gang-affiliated juvenile offenders participating in an employment counseling intervention. Weekly counseling sessions were audio-recorded, transcribed, and coded for commitment language strength. Multilevel models were fit to the data to examine the relationship between commitment language and counseling homework or employment outcomes within participants over time. Commitment language strength predicted subsequent homework completion but not weekly employment. These findings imply that gang-affiliated delinquent youth who express motivation to change during employment counseling will be more likely to comply with counselor-initiated homework. Further research on counselor techniques for promoting commitment language among juvenile gang offenders is needed. © The Author(s) 2013.

Mediating the Maltreatment-Delinquency Relationship: The Role of Triad Gang Membership.

Science.gov (United States)

Chui, Wing Hong; Khiatani, Paul Vinod

2018-02-01

The primary aim of this article is to examine the role of triad affiliation in mediating the relationship between child maltreatment (neglect, punishment, emotional abuse, and sexual abuse) and delinquency among active young gang members in Hong Kong. A sample of 177 gang members aged 12 to 24 was recruited to complete a questionnaire with the assistance of a youth outreach social work team. Neglect was identified as the most common form of maltreatment, followed by emotional abuse, punishment, and sexual abuse. Mediation analyses confirmed that triad affiliation acts as a mediating variable in the child maltreatment-delinquency relationship, except in cases of sexual abuse. Only the relationship between punishment and delinquency was found to be fully mediated by triad affiliation; partial mediation effects were found for neglect and emotional abuse. Recommendations for child protection and youth workers are provided.

Mission Impossible? Social Work Practice with Black Urban Youth Gangs.

Science.gov (United States)

Fox, Jerry R.

1985-01-01

Describes the adaptation of social work practice skills to serve black urban youth gangs. Presents a model for practice which respects youths' right to self-determination and community needs. Model stages discussed include contact, rapport, setting goals, assigning roles, procuring resources, and evaluation. Model applicability is suggested. (NRB)

"American" Abjection: "Chicanos," Gangs, and Mexican/Migrant Transnationality in Chicago

Science.gov (United States)

De Genova, Nicholas

2008-01-01

Crime and street violence often evoke racialized discourses about urban space. In this ethnographic research in Chicago, however, the disdain that many Mexican migrants articulated about street gangs principally concerned issues "internal" to the Mexican/Chicano community, notably a profound ambivalence about U.S.-born Mexicans and a…

Development of seasonal flow outlook model for Ganges-Brahmaputra Basins in Bangladesh

Science.gov (United States)

Hossain, Sazzad; Haque Khan, Raihanul; Gautum, Dilip Kumar; Karmaker, Ripon; Hossain, Amirul

2016-10-01

Bangladesh is crisscrossed by the branches and tributaries of three main river systems, the Ganges, Bramaputra and Meghna (GBM). The temporal variation of water availability of those rivers has an impact on the different water usages such as irrigation, urban water supply, hydropower generation, navigation etc. Thus, seasonal flow outlook can play important role in various aspects of water management. The Flood Forecasting and Warning Center (FFWC) in Bangladesh provides short term and medium term flood forecast, and there is a wide demand from end-users about seasonal flow outlook for agricultural purposes. The objective of this study is to develop a seasonal flow outlook model in Bangladesh based on rainfall forecast. It uses European Centre for Medium-Range Weather Forecasts (ECMWF) seasonal precipitation, temperature forecast to simulate HYDROMAD hydrological model. Present study is limited for Ganges and Brahmaputra River Basins. ARIMA correction is applied to correct the model error. The performance of the model is evaluated using coefficient of determination (R2) and Nash-Sutcliffe Efficiency (NSE). The model result shows good performance with R2 value of 0.78 and NSE of 0.61 for the Brahmaputra River Basin, and R2 value of 0.72 and NSE of 0.59 for the Ganges River Basin for the period of May to July 2015. The result of the study indicates strong potential to make seasonal outlook to be operationalized.

Functions of Aggression and Delinquency: The Moderating Role of Parent Criminality and Friends' Gang Membership.

Science.gov (United States)

Ang, Rebecca P; Huan, Vivien S; Li, Xiang; Chan, Wei Teng

2016-03-02

This study examined the relationships between two functions of aggression (i.e., reactive and proactive) and delinquency, including the moderating effects of parent criminality and friends' gang membership, in a sample of 1,027 Singaporean adolescents from Grade 7 to Grade 9, with age ranging from 12 to 19 years (M = 14.10, SD = 1.15). Findings suggested that both reactive aggression and proactive aggression significantly and positively predicted delinquency (after controlling for proactive aggression and reactive aggression, respectively), with proactive aggression being a stronger predictor. Friends' gang membership was found to moderate the relationship between reactive aggression and delinquency, and proactive aggression and delinquency, with stronger moderator effects for the latter. Those who were aggressive proactively and who had friends in a gang appear to be impacted most negatively with respect to delinquency. Parent criminality did not moderate these relationships. These findings highlight the need to effectively address the issues of child and adolescent aggression. Also, developing positive peer relations early is crucial for delinquency prevention. © The Author(s) 2016.

A Social Movement Theory Typology of Gang Violence

Science.gov (United States)

2010-06-01

Global Crime Empire (Great Britain: Hodder and Stoughton, 2006), 362. 9 Ori Brafman and Rod A. Beckstrom, The Starfish and the Spider (New York: The... educate , assist, or mentor those 16–22 year-old youths most affected by gang violence. One source of fiscal inequality found in Salinas is in local...of Salinas. Although there is little doubt that a modern library can serve as a beacon for youth education , there is little to suggest that this

Detecting Long-term Trend of Water Quality Indices of Dong-gang River, Taiwan Using Quantile Regression

Science.gov (United States)

Yang, D.; Shiau, J.

2013-12-01

ABSTRACT BODY: Abstract Surface water quality is an essential issue in water-supply for human uses and sustaining healthy ecosystem of rivers. However, water quality of rivers is easily influenced by anthropogenic activities such as urban development and wastewater disposal. Long-term monitoring of water quality can assess whether water quality of rivers deteriorates or not. Taiwan is a population-dense area and heavily depends on surface water for domestic, industrial, and agricultural uses. Dong-gang River is one of major resources in southern Taiwan for agricultural requirements. The water-quality data of four monitoring stations of the Dong-gang River for the period of 2000-2012 are selected for trend analysis. The parameters used to characterize water quality of rivers include biochemical oxygen demand (BOD), dissolved oxygen (DO), suspended solids (SS), and ammonia nitrogen (NH3-N). These four water-quality parameters are integrated into an index called river pollution index (RPI) to indicate the pollution level of rivers. Although widely used non-parametric Mann-Kendall test and linear regression exhibit computational efficiency to identify trends of water-quality indices, limitations of such approaches include sensitive to outliers and estimations of conditional mean only. Quantile regression, capable of identifying changes over time of any percentile values, is employed in this study to detect long-term trend of water-quality indices for the Dong-gang River located in southern Taiwan. The results show that Dong-gang River 4 stations from 2000 to 2012 monthly long-term trends in water quality.To analyze s Dong-gang River long-term water quality trends and pollution characteristics. The results showed that the bridge measuring ammonia Long-dong, BOD5 measure in that station on a downward trend, DO, and SS is on the rise, River Pollution Index (RPI) on a downward trend. The results form Chau-Jhou station also ahowed simialar trends .more and more near the

The Socialization Process of Street Children in the Youth Gangs and Groups of Organized Crime in Local Community. Preliminary Report

Directory of Open Access Journals (Sweden)

Małgorzata Michel

2013-12-01

Full Text Available This article includes the research report on the socialization process of children in the street, youth gangs, and organized criminal groups in local communities. The author has analysed the signs and communication codes located on walls in local communities. This is very important to the socialization process of the youth street gangs.

Assessing School-Based Gang Prevention Efforts in Urban Centers: Are These Programs Reaching Those Students Who May Benefit the Most?

Science.gov (United States)

Rodriguez, Hector

2009-01-01

In recent years, schools have become a focal point for general delinquency and gang prevention programs for a variety of reasons. One premise behind this approach is that schools can serve as ideal settings for providing delinquency and intervention services because youths spend so much time there. School-based gang prevention efforts are supposed…

Book review: Don Pinnock, Gang town | van der Spuy | South African ...

African Journals Online (AJOL)

Title: Gang town. Publisher: Tafelberg, Cape Town, 2016. Price: 312. Pages: R196 Availability: Published ISBN: 9780624067894. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for ...

Air Pollution Over the Ganges Basin and Northwest Bay of Bengal in the Early Postmonsoon Season Based on NASA MERRAero Data

Science.gov (United States)

Kishcha, Pavel; Da Silva, Arlindo M.; Starobinets, Boris; Alpert, Pinhas

2014-01-01

The MERRA Aerosol Reanalysis (MERRAero) has been recently developed at NASA's Global Modeling Assimilation Office. This reanalysis is based on a version of the Goddard Earth Observing System-5 (GEOS-5) model radiatively coupled with Goddard Chemistry, Aerosol, Radiation, and Transport aerosols, and it includes assimilation of bias-corrected aerosol optical thickness (AOT) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on both Terra and Aqua satellites. In October over the period 2002-2009, MERRAero showed that AOT was lower over the east of the Ganges basin than over the northwest of the Ganges basin: this was despite the fact that the east of the Ganges basin should have produced higher anthropogenic aerosol emissions because of higher population density, increased industrial output, and transportation. This is evidence that higher aerosol emissions do not always correspond to higher AOT over the areas where the effects of meteorological factors on AOT dominate those of aerosol emissions. MODIS AOT assimilation was essential for correcting modeled AOT mainly over the northwest of the Ganges basin, where AOT increments were maximal. Over the east of the Ganges basin and northwest Bay of Bengal (BoB), AOT increments were low and MODIS AOT assimilation did not contribute significantly to modeled AOT. Our analysis showed that increasing AOT trends over northwest BoB (exceeding those over the east of the Ganges basin) were reproduced by GEOS-5, not because of MODIS AOT assimilation butmainly because of the model capability of reproducing meteorological factors contributing to AOT trends. Moreover, vertically integrated aerosol mass flux was sensitive to wind convergence causing aerosol accumulation over northwest BoB.

City Life and Delinquency-Victimization, Fear of Crime and Gang Membership.

Science.gov (United States)

Savitz, Leonard D.; And Others

Over 500 black and 500 white boys born in 1957 and attending Philadelphia schools were interviewed along with their mothers. The data were analyzed to discover how educational aspirations, social values, quality of life, fear of crime, victimization, family structure, father-son interaction, social attachments, and gang affiliation affected the…

Copyright case a victory for science publishing

Science.gov (United States)

Cole, Stephen

An important victory for the financial health and future of scientific journals was won July 23 when Judge Pierre Leval of the Federal District Court in New York handed down his decision on the copyright infringement suit, American Geophysical Union, et al. v. Texaco Inc. Leval ruled that profit-making companies cannot photocopy copyrighted journal articles without permission and without compensating the copyright holder.The class action suit was brought in 1985 by AGU and six other scientific publishers on behalf of 8500 publishers worldwide who make their titles available for legal copying under licenses granted by the Copyright Clearance Center, Inc. This licensing system was designed in cooperation with major corporations to facilitate compliance with the 1976 Copyright Act. Although more than 200 companies now use the center, some corporations, such as Texaco, have not. The suit was initiated to force compliance with copyright law. The current decision is very important because it establishes legal precedents on the “fair use” issue.

Geomorphology of the Ganges fluvial system in the Himalayan foreland: an update

Directory of Open Access Journals (Sweden)

Rajiv Sinha

2004-12-01

Full Text Available The Ganges is one of the largest fluvial systems in the world rising from the loftiest Himalaya and draining into the Bay of Bengal. Together with the Brahmaputra, it also constitutes the largest delta in the world before finally meeting the sea. The Ganges system passes through a variety of terrain from the rugged mountains through the flat alluvial plains and the sea margin, and also transects variable climatic zones. As a result, the processes, landforms and stratigraphy are strikingly different in different zones of the system. This paper attempts to provide an update on our understanding of this very large and diverse system. A global effort has been made in the last few decades, and the research has focused on a variety of themes. The mountainous catchments have attracted attention in view of the extent of glaciation and extensive erosional processes. The alluvial plains of the Ganges symbolizes the life line of one of the world's largest population. Consequently, a number of studies have been carried out on the morphology, hydrology including flooding history and sediment transport behaviour of the river system. The alluvial stratigraphy of the large valleys and the interfluves in the plains has provided insight about the sedimentation pattern and response to climate change. The deltaic plain is the final destination of this huge sediment dispersal system before it drains into the sea, and it also records the influence of sea level changes apart from the upstream catchment controls over a period of time.

How groups contest depends on group power and the likelihood that power determines victory and defeat

NARCIS (Netherlands)

Kamans, Elanor; Otten, Sabine; Gordijn, Ernestine H.; Spears, Russell

2010-01-01

The aim of the current study was to show that the type of conflict behavior (constructive vs. unconstructive) groups use in conflicts depends on their power position as well as the likelihood that power determines victory and defeat. In an alleged online debate, we created a conflict between two

Barcelona and Madrid: Two different realities in the phenomenon of the Latino gangs

Directory of Open Access Journals (Sweden)

Miguel López Corral

2008-04-01

Full Text Available The Latino gangs that have come into existence in Spain represent a potential risk factor for citizens’ security and coexistence. That is the view of security forces and organisations, and it also seems to be the understanding reached by the administrations of the Autonomous Communities of Catalonia and Madrid, whose actions in the light of this phenomenon are assessed in this work. To this end, the author begins with an analysis of the significance of Latino gangs inSpain, from their origins to their introduction, and carries out a review of their current situation, including their organisation, recruitment, impact and risk for citizen security. Only with suchan analysis can one begin to comprehend the scenario of dangers that will appear in the future, and the police strategy that should be introduced to deal with the phenomenon.

“It’s like we’re just renting over here”: The Pervasive Experiences of Discrimination of Filipino Immigrant Youth Gang Members in Hawai’i

Science.gov (United States)

Kim, Su Yeong; Benner, Aprile D.; Takushi, Rena Mae Nalani; Ongbongan, Kathleen; Dennerlein, Donna; Spencer, Deborah K.

2009-01-01

Researchers, service providers, and policymakers must uncover and better understand the issues facing youths in Asian gangs in order to most effectively intervene with appropriate policies and programs. The present investigation sampled young male Filipino gang members in Hawai’i. Thematic analyses of the focus group data challenge the commonly held view of racial harmony in Hawai’i. It appears that racial and social discrimination from peers and authority figures propel Filipino boys to seek out gang membership as a way to protect themselves from being targets of oppression. PMID:19946383

Adaptation to changing water resources in the Ganges basin, northern India

International Nuclear Information System (INIS)

Moors, Eddy J.; Groot, Annemarie; Biemans, Hester; Terwisscha van Scheltinga, Catharien; Siderius, Christian; Stoffel, Markus; Huggel, Christian; Wiltshire, Andy; Mathison, Camilla; Ridley, Jeff; Jacob, Daniela; Kumar, Pankaj

2011-01-01

An ensemble of regional climate model (RCM) runs from the EU HighNoon project are used to project future air temperatures and precipitation on a 25 km grid for the Ganges basin in northern India, with a view to assessing impact of climate change on water resources and determining what multi-sector adaptation measures and policies might be adopted at different spatial scales. The RCM results suggest an increase in mean annual temperature, averaged over the Ganges basin, in the range 1-4 o C over the period from 2000 to 2050, using the SRES A1B forcing scenario. Projections of precipitation indicate that natural variability dominates the climate change signal and there is considerable uncertainty concerning change in regional annual mean precipitation by 2050. The RCMs do suggest an increase in annual mean precipitation in this region to 2050, but lack significant trend. Glaciers in headwater tributary basins of the Ganges appear to be continuing to decline but it is not clear whether meltwater runoff continues to increase. The predicted changes in precipitation and temperature will probably not lead to significant increase in water availability to 2050, but the timing of runoff from snowmelt will likely occur earlier in spring and summer. Water availability is subject to decadal variability, with much uncertainty in the contribution from climate change. Although global social-economic scenarios show trends to urbanization, locally these trends are less evident and in some districts rural population is increasing. Falling groundwater levels in the Ganges plain may prevent expansion of irrigated areas for food supply. Changes in socio-economic development in combination with projected changes in timing of runoff outside the monsoon period will make difficult choices for water managers. Because of the uncertainty in future water availability trends, decreasing vulnerability by augmenting resilience is the preferred way to adapt to climate change. Adaptive policies are

Humanitarian Protection for Children Fleeing Gang-Based Violence in the Americas

Directory of Open Access Journals (Sweden)

Elizabeth Carlson

2015-04-01

Full Text Available By the end of 2011, the US Customs and Border Protection (CBP began to see a steady rise in the number of Unaccompanied Alien Children (UAC from Central America, particularly from the Northern Triangle countries—El Salvador, Honduras and Guatemala—arriving to the US-Mexico border. The number of children entering the United States from these countries more than doubled during fiscal year (FY 2012 and continued to grow through FY 2014. In FY 2013, CBP apprehended over 35,000 children. That number almost doubled to 66,127 in FY 2014, with Central American children outnumbering their Mexican counterparts for the first time. Research has identified high levels of violence perpetrated by gangs and drug cartels in the Northern Triangle countries and Mexico as a primary reason for this surge. Under the William Wilberforce Trafficking Victims Protection Reauthorization Act (TVPRA passed with bi-partisan support in 2008, children from Central America cannot be immediately deported and must be given a court hearing.In contrast, unless there are indicia of trafficking, Mexican children are returned immediately to their country. Advocates have expressed concern that expedited removal of Mexican children places children with valid humanitarian claims at risk of being returned to harm, including forcible recruitment into drug cartels and trafficking rings. After the spike in arrivals in FY 2014, several members of Congress called for a change in the TVPRA, urging that Central American children be treated like Mexican children and undergo expedited procedures for their removal. Many of their constituents supported such measures. The Obama administration requested additional funds to strengthen border security, speed up deportation procedures and implement measures to address the humanitarian crisis in Central America. Groups and individuals across the country came together to provide shelter, medical and psychological care and legal representation to many

Findings from the Evaluation of OJJDP's Gang Reduction Program. Juvenile Justice Bulletin

Science.gov (United States)

Cahill, Meagan; Hayeslip, David

2010-01-01

This bulletin draws on findings from an independent evaluation, conducted by the Urban Institute, of the Gang Reduction Program's (GRP) Impact in Los Angeles, California; Milwaukee, Wisconsin; North Miami Beach, Florida; and Richmond, Virginia, to examine how effectively these sites implemented the program. Following are some of the authors' key…

The role of the Ganges-Brahmaputra mixing zone in supplying barium and 226Ra to the Bay of Bengal

International Nuclear Information System (INIS)

Carroll, J.; Falkner, K.K.; Brown, E.T.; Moore, W.S.

1993-01-01

The Ganges-Brahmaputra river system is ranked fourth among world rivers as a source of freshwater to the oceans and is believed to supply more sediment to the ocean than any other; 1.5 x 10 12 kg/yr (Milliman and Meade, 1983). Barium and 226 Ra are typically enriched in waters where sediment-laden rivers enter the ocean. As such, the Ganges-Brahmaputra is likely to produce globally significant barium and 226 Ra fluxes to the ocean. Water samples for barium and 226 Ra were collected within four major channels of the Ganges-Brahmaputra mixing zone during a period of low sediment and freshwater discharge. The data suggest that in addition to suspended sediments supplied directly from rivers, river sediments deposited during high discharge in mangroves and on islands are desorbing barium and 226 Ra to seawater. The release of barium and 226 Ra from these sediment deposits is out-of-phase with the direct supply of sediments from the rivers. Estimates of the annual fluxes of barium and 226 Ra from the Ganges-Brahmaputra mixing zone were also derived. The fluxes of barium and 226 Ra are 5.3 x 10 8 mol barium/yr and 9.5 x 10 14 dpm radium/yr. The first silicate and phosphate mixing profiles for this system are reported. 29 refs., 6 figs., 3 tabs

The future in the past: Victory, defeat, and grand strategy in the US, UK, France and Germany

NARCIS (Netherlands)

van Hooft, P.A.

2015-01-01

This book argues that victory and defeat in war shape the post-war grand strategies of states, specifically their use of military force and diplomacy. It focuses on the experiences of the belligerent states of the Second World War, and in particular on those of the United States, the United Kingdom,

Assessment of Environmental Flows for the Rivers of Western Ganges Delta with Special Reference to Indian Sundarban

Science.gov (United States)

Bhadra, T.; Hazra, S.; Ghosh, S.; Barman, B. C.

2016-12-01

The Indian Sundarban, situated on the western tide-dominated part of the Ganges delta was formed by the sedimentation of the Ganges and its tributaries. Freshwater is a scarce resource in the Sundarban though it is traversed by rivers. Most of the rivers of Western Ganges Delta, which used to nourish the Sundarban, have become defunct with the passage of time. To ensure sustainable flow and to enhance the flow-dependent ecosystem services in this region, assessment of environmental flows within the system is required. A pilot assessment of environment flows, supported by IUCN has been carried out in some specific river reaches of Western Ganges Delta under the present study. The holistic Building Block Methodology (BBM) has been modified and used for the assessment of environmental flows. In the modified BBM, three distinctive blocks namely Hydro-Morphology, Ecology and Socio-Economy have been selected and indicators like Ganges Dolphin (Platanista gangetica), Sundari tree (Heritiera fomes) and Hilsa fish (Tenualosa ilisha) etc. have been determined to assess the environmental flows. As the discharge data of the selected rivers are restricted in the public domain, the SWAT model has been run to generate the discharge data of the classified rivers. The Hydraulic model, HEC-RAS has been calibrated in the selected River reaches to assess the habitat availability and its changes for indicator species under different flow condition. The study reveals that River Bhagirathi-Hugli requires 150-427 cumec additional water in monsoon and 850-1127 cumec additional water in post-monsoon months for Hilsa migration, whereas 327-486 cumec additional water in pre-monsoon and dry season and 227-386 cumec additional water in post-monsoon months are required for Dolphin movement. Flow requirement of river Ichhamati has also been estimated under the present study. The total required flow for the Sundarban ecosystem to reduce the salinity level from 30ppt to 14ppt during the dry and pre

Countering Gang Violence: What Small Town Communities Can Learn from the US Military

Science.gov (United States)

2011-05-03

city is also home to two of the most notorious Hispanic gangs operating in the US. The Nuestra Familia and the Mexican Mafia have approximately 11...within Salinas until all communities are capable of self-policing. Critical to this mission will be Salinas‟ ability to actually „connect‟ with the

Advantages of Group Therapy for Adolescent Participants in the Same Gang Rape

Science.gov (United States)

Etgar, Talia; Prager, Keren Ganot

2009-01-01

This paper deals with the issue of including in the same therapeutic group in a prison setting two (or more) young people who participated in the same gang rape. We provide a background for group therapy with adolescent sex offenders and point out the characteristics of group rape. In addition, we describe the uniqueness of working in a prison as…

Predicting sexual coercion in early adulthood: The transaction among maltreatment, gang affiliation, and adolescent socialization of coercive relationship norms.

Science.gov (United States)

Ha, Thao; Kim, Hanjoe; Christopher, Caroline; Caruthers, Allison; Dishion, Thomas J

2016-08-01

This study tested a transactional hypothesis predicting early adult sexual coercion from family maltreatment, early adolescent gang affiliation, and socialization of adolescent friendships that support coercive relationship norms. The longitudinal study of a community sample of 998 11-year-olds was intensively assessed in early and middle adolescence and followed to 23-24 years of age. At age 16-17 youth were videotaped with a friend, and their interactions were coded for coercive relationship talk. Structural equation modeling revealed that maltreatment predicted gang affiliation during early adolescence. Both maltreatment and gang affiliation strongly predicted adolescent sexual promiscuity and coercive relationship norms with friends at age 16-17 years. Adolescent sexual promiscuity, however, did not predict sexual coercion in early adulthood. In contrast, higher levels of observed coercive relationship talk with a friend predicted sexual coercion in early adulthood for both males and females. These findings suggest that peers have a socialization function in the development of norms prognostic of sexual coercion, and the need to consider peers in the promotion of healthy relationships.

Clicking in shallow rivers: short-range echolocation of Irrawaddy and Ganges River dolphins in a shallow, acoustically complex habitat.

Directory of Open Access Journals (Sweden)

Frants H Jensen

Full Text Available Toothed whales (Cetacea, odontoceti use biosonar to navigate their environment and to find and catch prey. All studied toothed whale species have evolved highly directional, high-amplitude ultrasonic clicks suited for long-range echolocation of prey in open water. Little is known about the biosonar signals of toothed whale species inhabiting freshwater habitats such as endangered river dolphins. To address the evolutionary pressures shaping the echolocation signal parameters of non-marine toothed whales, we investigated the biosonar source parameters of Ganges river dolphins (Platanista gangetica gangetica and Irrawaddy dolphins (Orcaella brevirostris within the river systems of the Sundarban mangrove forest. Both Ganges and Irrawaddy dolphins produced echolocation clicks with a high repetition rate and low source level compared to marine species. Irrawaddy dolphins, inhabiting coastal and riverine habitats, produced a mean source level of 195 dB (max 203 dB re 1 µPapp whereas Ganges river dolphins, living exclusively upriver, produced a mean source level of 184 dB (max 191 re 1 µPapp. These source levels are 1-2 orders of magnitude lower than those of similar sized marine delphinids and may reflect an adaptation to a shallow, acoustically complex freshwater habitat with high reverberation and acoustic clutter. The centroid frequency of Ganges river dolphin clicks are an octave lower than predicted from scaling, but with an estimated beamwidth comparable to that of porpoises. The unique bony maxillary crests found in the Platanista forehead may help achieve a higher directionality than expected using clicks nearly an octave lower than similar sized odontocetes.

Linker-dependent Junction Formation Probability in Single-Molecule Junctions

Energy Technology Data Exchange (ETDEWEB)

Yoo, Pil Sun; Kim, Taekyeong [HankukUniversity of Foreign Studies, Yongin (Korea, Republic of)

2015-01-15

We compare the junction formation probabilities of single-molecule junctions with different linker molecules by using a scanning tunneling microscope-based break-junction technique. We found that the junction formation probability varies as SH > SMe > NH2 for the benzene backbone molecule with different types of anchoring groups, through quantitative statistical analysis. These results are attributed to different bonding forces according to the linker groups formed with Au atoms in the electrodes, which is consistent with previous works. Our work allows a better understanding of the contact chemistry in the metal.molecule junction for future molecular electronic devices.

Water resources management in the Ganges Basin: a comparison of three strategies for conjunctive use of groundwater and surface water

Science.gov (United States)

Khan, Mahfuzur R.; Voss, Clifford I.; Yu, Winston; Michael, Holly A.

2014-01-01

The most difficult water resources management challenge in the Ganges Basin is the imbalance between water demand and seasonal availability. More than 80 % of the annual flow in the Ganges River occurs during the 4-month monsoon, resulting in widespread flooding. During the rest of the year, irrigation, navigation, and ecosystems suffer because of water scarcity. Storage of monsoonal flow for utilization during the dry season is one approach to mitigating these problems. Three conjunctive use management strategies involving subsurface water storage are evaluated in this study: Ganges Water Machine (GWM), Pumping Along Canals (PAC), and Distributed Pumping and Recharge (DPR). Numerical models are used to determine the efficacy of these strategies. Results for the Indian State of Uttar Pradesh (UP) indicate that these strategies create seasonal subsurface storage from 6 to 37 % of the yearly average monsoonal flow in the Ganges exiting UP over the considered range of conditions. This has clear implications for flood reduction, and each strategy has the potential to provide irrigation water and to reduce soil waterlogging. However, GWM and PAC require significant public investment in infrastructure and management, as well as major shifts in existing water use practices; these also involve spatially-concentrated pumping, which may induce land subsidence. DPR also requires investment and management, but the distributed pumping is less costly and can be more easily implemented via adaptation of existing water use practices in the basin.

Implications of agricultural land use change to ecosystem services in the Ganges delta.

Science.gov (United States)

Islam, G M Tarekul; Islam, A K M Saiful; Shopan, Ahsan Azhar; Rahman, Md Munsur; Lázár, Attila N; Mukhopadhyay, Anirban

2015-09-15

Ecosystems provide the basis for human civilization and natural capital for green economy and sustainable development. Ecosystem services may range from crops, fish, freshwater to those that are harder to see such as erosion regulation, carbon sequestration, and pest control. Land use changes have been identified as the main sources of coastal and marine pollution in Bangladesh. This paper explores the temporal variation of agricultural land use change and its implications with ecosystem services in the Ganges delta. With time agricultural lands have been decreased and wetlands have been increased at a very high rate mainly due to the growing popularity of saltwater shrimp farming. In a span of 28 years, the agricultural lands have been reduced by approximately 50%, while the wetlands have been increased by over 500%. A large portion (nearly 40%) of the study area is covered by the Sundarbans which remained almost constant which can be attributed to the strict regulatory intervention to preserve the Sundarbans. The settlement & others land use type has also been increased to nearly 5%. There is a gradual uptrend of shrimp and fish production in the study area. The findings suggest that there are significant linkages between agricultural land use change and ecosystem services in the Ganges delta in Bangladesh. The continuous decline of agricultural land (due to salinization) and an increase of wetland have been attributed to the conversion of agricultural land into shrimp farming in the study area. Such land use change requires significant capital, therefore, only investors and wealthier land owners can get the higher profit from the land conversion while the poor people is left with the environmental consequences that affect their long-term lives and livelihood. An environmental management plan is proposed for sustainable land use in the Ganges delta in Bangladesh. Copyright © 2014 Elsevier Ltd. All rights reserved.

The movement and implications of the Ganges-Bramhaputra runoff on entering the Bay of Bengal

Digital Repository Service at National Institute of Oceanography (India)

Shetye, S.R.

The Ganges-Brahmaputra rivers discharge annually approximately 10 sup(2) m sup(3) of freshwater into the Bay of Bengal at its northern end. We propose that the spread of this water, accompaniEd. by mixing with the ambient waters, occurs in three...

Exogenous testosterone in women enhances and inhibits competitive decision-making depending on victory-defeat experience and trait dominance.

Science.gov (United States)

Mehta, Pranjal H; van Son, Veerle; Welker, Keith M; Prasad, Smrithi; Sanfey, Alan G; Smidts, Ale; Roelofs, Karin

2015-10-01

The present experiment tested the causal impact of testosterone on human competitive decision-making. According to prevailing theories about testosterone's role in social behavior, testosterone should directly boost competitive decisions. But recent correlational evidence suggests that testosterone's behavioral effects may depend on specific aspects of the context and person relevant to social status (win-lose context and trait dominance). We tested the causal influence of testosterone on competitive decisions by combining hormone administration with measures of trait dominance and a newly developed social competition task in which the victory-defeat context was experimentally manipulated, in a sample of 54 female participants. Consistent with the hypothesis that testosterone has context- and person-dependent effects on competitive behavior, testosterone increased competitive decisions after victory only among high-dominant individuals but testosterone decreased competitive decisions after defeat across all participants. These results suggest that testosterone flexibly modulates competitive decision-making depending on prior social experience and dominance motivation in the service of enhancing social status. Copyright © 2015 Elsevier Ltd. All rights reserved.

The construction of the gang in British Columbia : Mafioso, gangster, or thug? An examination of the uniqueness of the BC gangster phenomenon

OpenAIRE

McConnell, Keiron

2015-01-01

This thesis explores the structure, demographics, and history of gangs in British Columbia (BC), Canada, through a social constructionist lens. The purpose of this research is for the reader to consider the current state of gangs in BC as inherently different from other places in the world, to assist in understanding why there may be misconceptions, and to promote the research and implementation of more appropriate context-specific interventions. Building on previous work conducted as a Vanco...

Benchmarking wide swath altimetry-based river discharge estimation algorithms for the Ganges river system

Science.gov (United States)

Bonnema, Matthew G.; Sikder, Safat; Hossain, Faisal; Durand, Michael; Gleason, Colin J.; Bjerklie, David M.

2016-04-01

The objective of this study is to compare the effectiveness of three algorithms that estimate discharge from remotely sensed observables (river width, water surface height, and water surface slope) in anticipation of the forthcoming NASA/CNES Surface Water and Ocean Topography (SWOT) mission. SWOT promises to provide these measurements simultaneously, and the river discharge algorithms included here are designed to work with these data. Two algorithms were built around Manning's equation, the Metropolis Manning (MetroMan) method, and the Mean Flow and Geomorphology (MFG) method, and one approach uses hydraulic geometry to estimate discharge, the at-many-stations hydraulic geometry (AMHG) method. A well-calibrated and ground-truthed hydrodynamic model of the Ganges river system (HEC-RAS) was used as reference for three rivers from the Ganges River Delta: the main stem of Ganges, the Arial-Khan, and the Mohananda Rivers. The high seasonal variability of these rivers due to the Monsoon presented a unique opportunity to thoroughly assess the discharge algorithms in light of typical monsoon regime rivers. It was found that the MFG method provides the most accurate discharge estimations in most cases, with an average relative root-mean-squared error (RRMSE) across all three reaches of 35.5%. It is followed closely by the Metropolis Manning algorithm, with an average RRMSE of 51.5%. However, the MFG method's reliance on knowledge of prior river discharge limits its application on ungauged rivers. In terms of input data requirement at ungauged regions with no prior records, the Metropolis Manning algorithm provides a more practical alternative over a region that is lacking in historical observations as the algorithm requires less ancillary data. The AMHG algorithm, while requiring the least prior river data, provided the least accurate discharge measurements with an average wet and dry season RRMSE of 79.8% and 119.1%, respectively, across all rivers studied. This poor

Mareros and pandilleros in Honduras: the reintegration of youth gang members

OpenAIRE

Van Damme, Ellen

2016-01-01

The focus of this research is on the reintegration of youth gang members in Honduras. The aim of this qualitative study is to broaden the knowledge of reintegration processes and programs in one specific country in Central America, namely, Honduras. A sample of fourteen interviews with stakeholders in the field of maras and pandillas has been investigated and the results revealed some similarities between the different methods of reintegration. Our data suggest that a comprehensive process, i...

Differential Heating in the Indian Ocean Differentially Modulates Precipitation in the Ganges and Brahmaputra Basins

Directory of Open Access Journals (Sweden)

Md Shahriar Pervez

2016-10-01

Full Text Available Indo-Pacific sea surface temperature dynamics play a prominent role in Asian summer monsoon variability. Two interactive climate modes of the Indo-Pacific—the El Niño/Southern Oscillation (ENSO and the Indian Ocean dipole mode—modulate the amount of precipitation over India, in addition to precipitation over Africa, Indonesia, and Australia. However, this modulation is not spatially uniform. The precipitation in southern India is strongly forced by the Indian Ocean dipole mode and ENSO. In contrast, across northern India, encompassing the Ganges and Brahmaputra basins, the climate mode influence on precipitation is much less. Understanding the forcing of precipitation in these river basins is vital for food security and ecosystem services for over half a billion people. Using 28 years of remote sensing observations, we demonstrate that (i the tropical west-east differential heating in the Indian Ocean influences the Ganges precipitation and (ii the north-south differential heating in the Indian Ocean influences the Brahmaputra precipitation. The El Niño phase induces warming in the warm pool of the Indian Ocean and exerts more influence on Ganges precipitation than Brahmaputra precipitation. The analyses indicate that both the magnitude and position of the sea surface temperature anomalies in the Indian Ocean are important drivers for precipitation dynamics that can be effectively summarized using two new indices, one tuned for each basin. These new indices have the potential to aid forecasting of drought and flooding, to contextualize land cover and land use change, and to assess the regional impacts of climate change.

Differential heating in the Indian Ocean differentially modulates precipitation in the Ganges and Brahmaputra basins

Science.gov (United States)

Pervez, Md Shahriar; Henebry, Geoffrey M.

2016-01-01

Indo-Pacific sea surface temperature dynamics play a prominent role in Asian summer monsoon variability. Two interactive climate modes of the Indo-Pacific—the El Niño/Southern Oscillation (ENSO) and the Indian Ocean dipole mode—modulate the amount of precipitation over India, in addition to precipitation over Africa, Indonesia, and Australia. However, this modulation is not spatially uniform. The precipitation in southern India is strongly forced by the Indian Ocean dipole mode and ENSO. In contrast, across northern India, encompassing the Ganges and Brahmaputra basins, the climate mode influence on precipitation is much less. Understanding the forcing of precipitation in these river basins is vital for food security and ecosystem services for over half a billion people. Using 28 years of remote sensing observations, we demonstrate that (i) the tropical west-east differential heating in the Indian Ocean influences the Ganges precipitation and (ii) the north-south differential heating in the Indian Ocean influences the Brahmaputra precipitation. The El Niño phase induces warming in the warm pool of the Indian Ocean and exerts more influence on Ganges precipitation than Brahmaputra precipitation. The analyses indicate that both the magnitude and position of the sea surface temperature anomalies in the Indian Ocean are important drivers for precipitation dynamics that can be effectively summarized using two new indices, one tuned for each basin. These new indices have the potential to aid forecasting of drought and flooding, to contextualize land cover and land use change, and to assess the regional impacts of climate change.

Gangs and guilt: Towards a new theory of horror film

OpenAIRE

Kord, S. T.

2016-01-01

The most basic and unanimous statement made in scholarship on horror films is that horror films are ‘about’ fear: the primary purpose of horror films is to scare viewers. Based on horror films from the 1970s until the present in which child gangs play a significant part, this essay advances a new theory of horror film, namely that horror films primarily seek to elicit not fear but guilt. The analysis focuses on four topics: themes, camera angles, horror’s cinematic casting of ‘abnormality,’ a...

Assessing regional climate simulations of the last 30 years (1982-2012) over Ganges-Brahmaputra-Meghna River Basin

Science.gov (United States)

Khandu; Awange, Joseph L.; Anyah, Richard; Kuhn, Michael; Fukuda, Yoichi

2017-10-01

The Ganges-Brahmaputra-Meghna (GBM) River Basin presents a spatially diverse hydrological regime due to it's complex topography and escalating demand for freshwater resources. This presents a big challenge in applying the current state-of-the-art regional climate models (RCMs) for climate change impact studies in the GBM River Basin. In this study, several RCM simulations generated by RegCM4.4 and PRECIS are assessed for their seasonal and interannual variations, onset/withdrawal of the Indian monsoon, and long-term trends in precipitation and temperature from 1982 to 2012. The results indicate that in general, RegCM4.4 and PRECIS simulations appear to reasonably reproduce the mean seasonal distribution of precipitation and temperature across the GBM River Basin, although the two RCMs are integrated over a different domain size. On average, the RegCM4.4 simulations overestimate monsoon precipitation by {˜ }26 and {˜ }5% in the Ganges and Brahmaputra-Meghna River Basin, respectively, while PRECIS simulations underestimate (overestimate) the same by {˜ }7% ({˜ }16%). Both RegCM4.4 and PRECIS simulations indicate an intense cold bias (up to 10° C) in the Himalayas, and are generally stronger in the RegCM4.4 simulations. Additionally, they tend to produce high precipitation between April and May in the Ganges (RegCM4.4 simulations) and Brahmaputra-Meghna (PRECIS simulations) River Basins, resulting in early onset of the Indian monsoon in the Ganges River Basin. PRECIS simulations exhibit a delayed monsoon withdrawal in the Brahmaputra-Meghna River Basin. Despite large spatial variations in onset and withdrawal periods across the GBM River Basin, the basin-averaged results agree reasonably well with the observed periods. Although global climate model (GCM) driven simulations are generally poor in representing the interannual variability of precipitation and winter temperature variations, they tend to agree well with observed precipitation anomalies when driven by

Drugs, Gangs, Transnational Organized Crime and Malgoverened Spaces in the Americas

Science.gov (United States)

2015-01-01

including Los Zetas expanded into “ franchises ” in Central America,28 pou- ring new resources into the patchwork of gangs and transport groups in that...html. 39. Randal C. Archibold, “Gangs’ Truce Buys El Salvador a Tenuous Peace,” New York Times, August 27, 2012, http: //www.nytimes.com/2012/08/28...center/press-releases/Pages/tg1733.aspx. 51. Randal C. Archibold, “Gangs’ Truce Buys El Salvador a Tenuous Peace,” New York Times, August 27, 2012, http

SPECT/CT co-registration of nuclear medicine studies and technologists: challenges and victories

International Nuclear Information System (INIS)

Cameron, P.J.

2002-01-01

Full text: A dual modality SPECT/CT gamma camera was installed in the Department of Nuclear Medicine at Fremantle Hospital, WA in 2000. The challenges were satisfying the requirements of the Radiological Advisory Council of WA with respect to room modifications and presence of a radiographer during CT acquisitions and once installation was complete, learning to operate the camera in dual modality mode. The victories are making CT/SPECT acquisitions a simple and routine procedure and the impact of the co-registered studies in both diagnostic and therapeutic applications in our practice. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

Soil Gas Sample Handling: Evaluation of Water Removal and Sample Ganging

Energy Technology Data Exchange (ETDEWEB)

Fritz, Brad G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Abrecht, David G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hayes, James C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mendoza, Donaldo P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-10-31

Soil gas sampling is currently conducted in support of Nuclear Test Ban treaty verification. Soil gas samples are collected and analyzed for isotopes of interest. Some issues that can impact sampling and analysis of these samples are excess moisture and sample processing time. Here we discuss three potential improvements to the current sampling protocol; a desiccant for water removal, use of molecular sieve to remove CO₂ from the sample during collection, and a ganging manifold to allow composite analysis of multiple samples.

Gap Junctions

Science.gov (United States)

Nielsen, Morten Schak; Axelsen, Lene Nygaard; Sorgen, Paul L.; Verma, Vandana; Delmar, Mario; Holstein-Rathlou, Niels-Henrik

2013-01-01

Gap junctions are essential to the function of multicellular animals, which require a high degree of coordination between cells. In vertebrates, gap junctions comprise connexins and currently 21 connexins are known in humans. The functions of gap junctions are highly diverse and include exchange of metabolites and electrical signals between cells, as well as functions, which are apparently unrelated to intercellular communication. Given the diversity of gap junction physiology, regulation of gap junction activity is complex. The structure of the various connexins is known to some extent; and structural rearrangements and intramolecular interactions are important for regulation of channel function. Intercellular coupling is further regulated by the number and activity of channels present in gap junctional plaques. The number of connexins in cell-cell channels is regulated by controlling transcription, translation, trafficking, and degradation; and all of these processes are under strict control. Once in the membrane, channel activity is determined by the conductive properties of the connexin involved, which can be regulated by voltage and chemical gating, as well as a large number of posttranslational modifications. The aim of the present article is to review our current knowledge on the structure, regulation, function, and pharmacology of gap junctions. This will be supported by examples of how different connexins and their regulation act in concert to achieve appropriate physiological control, and how disturbances of connexin function can lead to disease. © 2012 American Physiological Society. Compr Physiol 2:1981-2035, 2012. PMID:23723031

Rehabilitation of Platanista gangetica (Lebeck, 1801) as the valid scientific name of the Ganges dolphin

NARCIS (Netherlands)

Kinze, C.C.

2000-01-01

The Dutch scientist Heinrich Julius Lebeck’s description of the Ganges dolphin is, based on a deduced latest date of publication 24 August 1801, given priority over William Roxburgh’s account of the same species, for which no precise date could be established. Although very similar to the work of

76 FR 61279 - Defense Federal Acquisition Regulation Supplement; Defense Cargo Riding Gang Member (DFARS Case...

Science.gov (United States)

2011-10-04

... that the language of the proposed clause be amended to read as follows to reinforce DoD's role in the... Military Sealift Command), and specific procedural guidance for DoD personnel obtaining the background... 247.5. B. Language Inconsistency Comment: DFARS 252.247-7027(a) defines ``riding gang member'' as it...

Bullies, Gangs, Drugs, and School: Understanding the Overlap and the Role of Ethnicity and Urbanicity

Science.gov (United States)

Bradshaw, Catherine P.; Waasdorp, Tracy Evian; Goldweber, Asha; Johnson, Sarah Lindstrom

2013-01-01

Recent media attention has increased interest in behavioral, mental health, and academic correlates of involvement in bullying. Yet, there has not been much interest in investigating the co-occurrence of other health-risk behaviors, such as gang membership, weapon carrying, and substance use. The potential influence of contextual factors, such as…

Public School Uniforms: Effect on Perceptions of Gang Presence, School Climate, and Student Self-Perceptions.

Science.gov (United States)

Wade, Kathleen Kiley; Stafford, Mary E.

2003-01-01

Examined the relationship between public school uniforms and student self-worth and student and staff perceptions of gang presence and school climate. Surveys of middle school students and teachers indicated that although students' perceptions did not vary across uniform policy, teachers from schools with uniform policies perceived lower levels of…

Flood Risk Assessment and Forecasting for the Ganges-Brahmaputra-Meghna River Basins

Science.gov (United States)

Hopson, T. M.; Priya, S.; Young, W.; Avasthi, A.; Clayton, T. D.; Brakenridge, G. R.; Birkett, C. M.; Riddle, E. E.; Broman, D.; Boehnert, J.; Sampson, K. M.; Kettner, A.; Singh, D.

2017-12-01

During the 2017 South Asia monsoon, torrential rains and catastrophic floods affected more than 45 million people, including 16 million children, across the Ganges-Brahmaputra-Meghna (GBM) basins. The basin is recognized as one of the world's most disaster-prone regions, with severe floods occurring almost annually causing extreme loss of life and property. In light of this vulnerability, the World Bank and collaborators have contributed toward reducing future flood impacts through recent developments to improve operational preparedness for such events, as well as efforts in more general preparedness and resilience building through planning based on detailed risk assessments. With respect to improved event-specific flood preparedness through operational warnings, we discuss a new forecasting system that provides probability-based flood forecasts developed for more than 85 GBM locations. Forecasts are available online, along with near-real-time data maps of rainfall (predicted and actual) and river levels. The new system uses multiple data sets and multiple models to enhance forecasting skill, and provides improved forecasts up to 16 days in advance of the arrival of high waters. These longer lead times provide the opportunity to save both lives and livelihoods. With sufficient advance notice, for example, farmers can harvest a threatened rice crop or move vulnerable livestock to higher ground. Importantly, the forecasts not only predict future water levels but indicate the level of confidence in each forecast. Knowing whether the probability of a danger-level flood is 10 percent or 90 percent helps people to decide what, if any, action to take. With respect to efforts in general preparedness and resilience building, we also present a recent flood risk assessment, and how it provides, for the first time, a numbers-based view of the impacts of different size floods across the Ganges basin. The findings help identify priority areas for tackling flood risks (for

The USSR Victory in World War II and the Emergence of the Independent Republic of Indonesia

Directory of Open Access Journals (Sweden)

Larisa M. Efimova

2015-01-01

Full Text Available Victorious ending of the World War 2 on May, 9, 1945, stroke a crushing blow on the military axis Berlin - Rome - Tokyo. The USSR played a decisive role both on European and Asian fronts. Fulfilling its allied duty the Soviet Union entered the war in the Far East on 9 August, 1945 and defeated the Japanese army in Manchuria. This act became a great contribution to liberation of Asian peoples from the Japanese occupation. On the 17 August 1945 the Republic of Indonesia declared its independence. The recognition on the side of international community as well as diplomatic support became\\e vital for the survival of the newly emerged Republic.The Soviet victory together with the allied nations in the Second World War, the new status of the USSR as a superpower, its constant anticolonial stance stimulated former colonies to appeal to the Soviet Union for backing and support. One of the first was the Republic of Indonesia, to which the USSR rendered all kind of help and encourages. The present article which is a result of the study of newly available documents from several recently opened Soviet archives shows the Soviet backing of Indonesia in the UN, its diplomatic recognition, in strengthening of Indonesian status as a sovereign state on the international arena as a whole.

The role of meteorological conditions and pollution control strategies in reducing air pollution in Beijing during APEC 2014 and Victory Parade 2015

Science.gov (United States)

Liang, Pengfei; Zhu, Tong; Fang, Yanhua; Li, Yingruo; Han, Yiqun; Wu, Yusheng; Hu, Min; Wang, Junxia

2017-11-01

To control severe air pollution in China, comprehensive pollution control strategies have been implemented throughout the country in recent years. To evaluate the effectiveness of these strategies, the influence of meteorological conditions on levels of air pollution needs to be determined. Using the intensive air pollution control strategies implemented during the Asia-Pacific Economic Cooperation Forum in 2014 (APEC 2014) and the 2015 China Victory Day Parade (Victory Parade 2015) as examples, we estimated the role of meteorological conditions and pollution control strategies in reducing air pollution levels in Beijing. Atmospheric particulate matter of aerodynamic diameter ≤ 2.5 µm (PM2.5) samples were collected and gaseous pollutants (SO2, NO, NOx, and O3) were measured online at a site in Peking University (PKU). To determine the influence of meteorological conditions on the levels of air pollution, we first compared the air pollutant concentrations during days with stable meteorological conditions. However, there were few days with stable meteorological conditions during the Victory Parade. As such, we were unable to estimate the level of emission reduction efforts during this period. Finally, a generalized linear regression model (GLM) based only on meteorological parameters was built to predict air pollutant concentrations, which could explain more than 70 % of the variation in air pollutant concentration levels, after incorporating the nonlinear relationships between certain meteorological parameters and the concentrations of air pollutants. Evaluation of the GLM performance revealed that the GLM, even based only on meteorological parameters, could be satisfactory to estimate the contribution of meteorological conditions in reducing air pollution and, hence, the contribution of control strategies in reducing air pollution. Using the GLM, we found that the meteorological conditions and pollution control strategies contributed 30 and 28 % to the reduction

Control rod pattern exchange in a BWR/6 utilizing gang mode withdrawal

International Nuclear Information System (INIS)

Auvil, A.B. Jr.; Aldemir, T.; Hajek, B.K.

1986-01-01

The use of checkerboard pattern of alternating inserted and fully withdrawn control rods and the uneven void distribution in boiling water reactor (BWR) cores can cause large burnup gradients even after a short time of operation. To compensate for these effects, power has to be reshaped periodically (typically every two full-power months) by individually manipulating the control rods. During this manipulation process (called the control rod pattern exchange), the core power is reduced to 60% of nominal power by means of flow reduction to limit power swings to tolerable levels and to ensure that fuel thermal limits are not exceeded. A control rod pattern exchange by individual rod manipulation typically takes 4 to 8 h and represents a large cost burden to the utility in terms of reduced system output. The latest generation of BWRs, the BWR/6, possesses the capability to simultaneously move up to four symmetrically located control rods. The rods corresponding to a given gang may have rotational symmetry, mirror symmetry, or a combination of the two. This paper presents a pattern exchange procedure that exploits the capability of gang mode rod withdrawal to reduce the pattern exchange execution time and radial power distribution asymmetry associated with individual rod manipulation. The working model used in the study is the Perry Nuclear Power Plant Unit 1, located in Perry, Ohio, and owned by the Cleveland Electric Illuminating Company

Four-junction superconducting circuit

Science.gov (United States)

Qiu, Yueyin; Xiong, Wei; He, Xiao-Ling; Li, Tie-Fu; You, J. Q.

2016-01-01

We develop a theory for the quantum circuit consisting of a superconducting loop interrupted by four Josephson junctions and pierced by a magnetic flux (either static or time-dependent). In addition to the similarity with the typical three-junction flux qubit in the double-well regime, we demonstrate the difference of the four-junction circuit from its three-junction analogue, including its advantages over the latter. Moreover, the four-junction circuit in the single-well regime is also investigated. Our theory provides a tool to explore the physical properties of this four-junction superconducting circuit. PMID:27356619

Nuevo puente sobre el río Ganges

Directory of Open Access Journals (Sweden)

S. Sarwal

1960-07-01

Full Text Available Recientemente se ha puesto en servicio un nuevo puente sobre el río Ganges, a unos cinco kilómetros aguas abajo de la estación ferroviaria de Mokameh Ghat, del Estado de Bihar, en la India. La obra consta de 14 tramos principales, de unos 120 m, aproximadamente, de luz cada uno, y 4 tramos, dos en cada extremidad, de 30 m de luz, que constituyen un total de 1.820 m de longitud. El puente tiene dos tableros: el superior, de 7,30 m de anchura, destinado a un paso de carretera, y el inferior, convenientemente separado, para el paso de un ferrocarril. Entre la parte inferior del puente y el nivel de aguas se ha dejado una altura libre de 10,50 m para el paso de la navegación fluvial.

Ganges Valley Aerosol Experiment (GVAX) Final Campaign Report

Energy Technology Data Exchange (ETDEWEB)

Kotamarthi, VR [Argonne National Laboratory

2013-12-01

In general, the Indian Summer Monsoon (ISM) as well as the and the tropical monsoon climate is influenced by a wide range of factors. Under various climate change scenarios, temperatures over land and into the mid troposphere are expected to increase, intensifying the summer pressure gradient differential between land and ocean and thus strengthening the ISM. However, increasing aerosol concentration, air pollution, and deforestation result in changes to surface albedo and insolation, potentially leading to low monsoon rainfall. Clear evidence points to increasing aerosol concentrations over the Indian subcontinent with time, and several hypotheses regarding the effect on monsoons have been offered. The Ganges Valley Aerosol Experiment (GVAX) field study aimed to provide critical data to address these hypotheses and contribute to developing better parameterizations for tropical clouds, convection, and aerosol-cloud interactions. The primary science questions for the mission were as follows:

Chain Gang-The Chemistry of Polymers (edited by Mickey Sarquis)

Science.gov (United States)

Collard, David M.

1999-01-01

Science in Our World, Vol. 5. Mickey Sarquis, series editor. Terrific Science Press: Middletown, OH, 1995. xiv + 149 pp. ISBN 1-883822-13-0. Spiral-bound, $13.95. Our familiarity with plastics makes polymers ideal examples of chemicals for discussion in K-12 science classes. Most importantly, polymers can be used as examples of chemicals that are safe to handle and of obvious use to society. The structures of polymers are easily represented by a number of models. These simple models go a long way in explaining the familiar physical properties of plastics. However, the introduction of polymers in the classroom relies on the availability of teaching material, experiments, and demonstrations that illustrate concepts in the current science curriculum. Chain Gang-The Chemistry of Polymers, one of the Science in Our World series published by the Center for Chemical Education at Miami University-Middletown (Ohio), will serve as a great resource for teachers interested in providing their students with a series of activities that can be related to their everyday experiences with these ubiquitous chemicals. After a brief introduction to some basic concepts, the book presents a series of 23 experiments. The collection of experiments presented here spans illustrations of chemistry, physical properties, analysis, and processing. Each experiment is recommended as either a hands-on activity or demonstration for various grade levels. A guide for the teacher suggests how the experiment can be used to illustrate topics in the science curriculum. The materials required for each activity are listed in detail, with quantities and sources (all materials are available from Flinn Scientific or hardware stores). There are detailed instructions for preparation of each experiment and how to introduce the experiment to students, and step-by-step instructions for activity. Very importantly, safety and disposal issues are clearly presented. Suggestions for cross-curriculum integration are also

Ballistic Graphene Josephson Junctions from the Short to the Long Junction Regimes.

Science.gov (United States)

Borzenets, I V; Amet, F; Ke, C T; Draelos, A W; Wei, M T; Seredinski, A; Watanabe, K; Taniguchi, T; Bomze, Y; Yamamoto, M; Tarucha, S; Finkelstein, G

2016-12-02

We investigate the critical current I_{C} of ballistic Josephson junctions made of encapsulated graphene-boron-nitride heterostructures. We observe a crossover from the short to the long junction regimes as the length of the device increases. In long ballistic junctions, I_{C} is found to scale as ∝exp(-k_{B}T/δE). The extracted energies δE are independent of the carrier density and proportional to the level spacing of the ballistic cavity. As T→0 the critical current of a long (or short) junction saturates at a level determined by the product of δE (or Δ) and the number of the junction's transversal modes.

Equivalent Josephson junctions

International Nuclear Information System (INIS)

Boyadzhiev, T.L.; ); Semerdzhieva, E.G.; Shukrinov, Yu.M.; Fiziko-Tekhnicheskij Inst., Dushanbe

2008-01-01

The magnetic field dependences of critical current are numerically constructed for a long Josephson junction with a shunt- or resistor-type microscopic inhomogeneities and compared to the critical curve of a junction with exponentially varying width. The numerical results show that it is possible to replace the distributed inhomogeneity of a long Josephson junction by an inhomogeneity localized at one of its ends, which has certain technological advantages. It is also shown that the critical curves of junctions with exponentially varying width and inhomogeneities localized at the ends are unaffected by the mixed fluxon-antifluxon distributions of the magnetic flux [ru

Of pandillas, pirucas, and Pablo Escobar in the barrio : Historical change and continuity in Nicaraguan gang violence

NARCIS (Netherlands)

Rodgers, D.; Huhn, S.; Warnecke-Berger, H.

2017-01-01

The putatively unprecedented rise to prominence of Central American youth gangs during the past two decades and a half is widely seen to epitomize the critical transformation that the region’s post-Cold War political economy of violence has undergone, moving from being predominantly related to

Junction and circuit fabrication

International Nuclear Information System (INIS)

Jackel, L.D.

1980-01-01

Great strides have been made in Josephson junction fabrication in the four years since the first IC SQUID meeting. Advances in lithography have allowed the production of devices with planar dimensions as small as a few hundred angstroms. Improved technology has provided ultra-high sensitivity SQUIDS, high-efficiency low-noise mixers, and complex integrated circuits. This review highlights some of the new fabrication procedures. The review consists of three parts. Part 1 is a short summary of the requirements on junctions for various applications. Part 2 reviews intergrated circuit fabrication, including tunnel junction logic circuits made at IBM and Bell Labs, and microbridge radiation sources made at SUNY at Stony Brook. Part 3 describes new junction fabrication techniques, the major emphasis of this review. This part includes a discussion of small oxide-barrier tunnel junctions, semiconductor barrier junctions, and microbridge junctions. Part 3 concludes by considering very fine lithography and limitations to miniaturization. (orig.)

Effect on water resources from upstream water diversion in the Ganges basin.

Science.gov (United States)

Adel, M M

2001-01-01

Bangladesh faces at least 30 upstream water diversion constructions of which Farakka Barrage is the major one. The effects of Farakka Barrage on water resources, socioeconomy, and culture have been investigated downstream in the basins of the Ganges and its distributaries. A diversion of up to 60% of the Ganges water over 25 yr has caused (i) reduction of water in surface water resources, (ii) increased dependence on ground water, (iii) destruction of the breeding and raising grounds for 109 species of Gangetic fishes and other aquatic species and amphibians, (iv) increased malnutrition, (v) deficiency in soil organic matter content, (vi) change in the agricultural practices, (vii) eradication of inland navigable routes, (viii) outbreak of waterborne diseases, (ix) loss of professions, and (x) obstruction to religious observances and pastimes. Further, arsenopyrites buried in the prebarrage water table have come in contact with air and formed water-soluble compounds of arsenic. Inadequate recharging of ground water hinders the natural cleansing of arsenic, and threatens about 75,000,000 lives who are likely to use water contaminated with up to 2 mg/L of arsenic. Furthermore, the depletion of surface water resources has caused environmental heating and cooling effects. Apart from these effects, sudden releases of water by the barrage during the flood season cause devestating floods. In consideration of such a heavy toll for the areas downstream, strict international rules have to be laid down to preserve the riparian ecosystems.

Major identity transformations - movements beyond criminal life and the biker gang environment

DEFF Research Database (Denmark)

Mørck, Line Lerche; Hansen, Peter

2015-01-01

. Empirically the paper illustrates these transitions and transformations with an empirical case of a young man, called Peter, changing his life conduct becoming less of a criminal member of the (biker) gang environment becoming more of a member of academia. The paper explore the action reasons of Peter...... logs, biographical documentaries and life story presentations to reflect identity change, which also becomes reflected part of the moment-movement research. The paper explore the struggles to move beyond marginal positions and how collective processes of recognition and reification might help about...

Nature of distribution of mercury in the sediments of the river Yamuna (tributary of the Ganges), India.

Science.gov (United States)

Subramanian, V; Madhavan, N; Saxena, Rajinder; Lundin, Lars-Christer

2003-06-01

Suspended Particulate Matter (SPM), surface (bed sediments) and short length cores of sediments collected from the largest tributary of the river Ganges, namely the river Yamuna, were analysed for total mercury as well as its fractionation in various size and chemical sites in the sediments following standard procedures. Also, attempts were made to determine the vertical distribution in sediments in relation to the recent timescale of a few decades. Our observations indicate that the SPM in general showed higher levels of total mercury compared to the surface sediments while at places the enhancement could be by a factor of 10, say around 25 microg g(-1) in the downstream region that integrates the industrial midstream and agricultural downstream terrain near its confluence with the Ganges. Surface sediments in the upstream direction near the Himalayan foothills and SPM in the lower reaches showed significant high Index of Geoaccumulation (Igeo) as defined by Müller. Size fractionation studies indicate that the finer fraction preferentially showed higher levels of mercury while in the lower reaches of the river, the total mercury is equitably distributed among all size fractions. The proportion of the residual fraction of mercury in relation to mobile fractions, in general decreases downstream towards its confluence with the Ganges river. In sediment cores, the vertical distribution show systematic peaks of mercury indicating that addition of this toxic metal to the aquatic system is in direct proportion to the increase in various types of human activities such as thermal power plants, land use changes (urbanisation) in the midstream region and intensive fertiliser application in lower reaches of this vast river basin.

Fifteen Years (1993–2007 of Surface Freshwater Storage Variability in the Ganges-Brahmaputra River Basin Using Multi-Satellite Observations

Directory of Open Access Journals (Sweden)

Edward Salameh

2017-03-01

Full Text Available Surface water storage is a key component of the terrestrial hydrological and biogeochemical cycles that also plays a major role in water resources management. In this study, surface water storage (SWS variations are estimated at monthly time-scale over 15 years (1993–2007 using a hypsographic approach based on the combination of topographic information from Advance Spaceborne Thermal Emission and Reflection Radiometer (ASTER and Hydrological Modeling and Analysis Platform (HyMAP-based Global Digital Elevation Models (GDEM and the Global Inundation Extent Multi-Satellite (GIEMS product in the Ganges-Brahmaputra basin. The monthly variations of the surface water storage are in good accordance with precipitation from Global Precipitation Climatology Project (GPCP, river discharges at the outlet of the Ganges and the Brahmaputra, and terrestrial water storage (TWS from the Gravity Recovery And Climate Experiment (GRACE, with correlations higher than 0.85. Surface water storage presents a strong seasonal signal (~496 km3 estimated by GIEMS/ASTER and ~378 km3 by GIEMS/HyMAPs, representing ~51% and ~41% respectively of the total water storage signal and it exhibits a large inter-annual variability with strong negative anomalies during the drought-like conditions of 1994 or strong positive anomalies such as in 1998. This new dataset of SWS is a new, highly valuable source of information for hydrological and climate modeling studies of the Ganges-Brahmaputra river basin.

Clay mineral distribution in the continental shelf sediments from Krishna to Ganges river mouth, east coast of India

Digital Repository Service at National Institute of Oceanography (India)

Rao, V.P.

Ninety six sediment samples (less than 2 mu m fractions) of the eastern continental shelf of India between Ganges in the north and Krishna in the south have been studiEd. by X-ray diffraction. On the basis of nature and abundance of different clay...

Macroscopic quantum tunneling in Josephson tunnel junctions and Coulomb blockade in single small tunnel junctions

International Nuclear Information System (INIS)

Cleland, A.N.

1991-04-01

Experiments investigating the process of macroscopic quantum tunneling in a moderately-damped, resistively shunted, Josephson junction are described, followed by a discussion of experiments performed on very small capacitance normal-metal tunnel junctions. The experiments on the resistively-shunted Josephson junction were designed to investigate a quantum process, that of the tunneling of the Josephson phase variable under a potential barrier, in a system in which dissipation plays a major role in the dynamics of motion. All the parameters of the junction were measured using the classical phenomena of thermal activation and resonant activation. Theoretical predictions are compared with the experimental results, showing good agreement with no adjustable parameters; the tunneling rate in the moderately damped (Q ∼ 1) junction is seen to be reduced by a factor of 300 from that predicted for an undamped junction. The phase is seen to be a good quantum-mechanical variable. The experiments on small capacitance tunnel junctions extend the measurements on the larger-area Josephson junctions from the region in which the phase variable has a fairly well-defined value, i.e. its wavefunction has a narrow width, to the region where its value is almost completely unknown. The charge on the junction becomes well-defined and is predicted to quantize the current through the junction, giving rise to the Coulomb blockade at low bias. I present the first clear observation of the Coulomb blockade in single junctions. The electrical environment of the tunnel junction, however, strongly affects the behavior of the junction: higher resistance leads are observed to greatly sharpen the Coulomb blockade over that seen with lower resistance leads. I present theoretical descriptions of how the environment influences the junctions; comparisons with the experimental results are in reasonable agreement

Josephson junction arrays

International Nuclear Information System (INIS)

Bindslev Hansen, J.; Lindelof, P.E.

1985-01-01

In this review we intend to cover recent work involving arrays of Josephson junctions. The work on such arrays falls naturally into three main areas of interest: 1. Technical applications of Josephson junction arrays for high-frequency devices. 2. Experimental studies of 2-D model systems (Kosterlitz-Thouless phase transition, commensurate-incommensurate transition in frustrated (flux) lattices). 3. Investigations of phenomena associated with non-equilibrium superconductivity in and around Josephson junctions (with high current density). (orig./BUD)

Electronic thermometry in tunable tunnel junction

Science.gov (United States)

Maksymovych, Petro

2016-03-15

A tunable tunnel junction thermometry circuit includes a variable width tunnel junction between a test object and a probe. The junction width is varied and a change in thermovoltage across the junction with respect to the change in distance across the junction is determined. Also, a change in biased current with respect to a change in distance across the junction is determined. A temperature gradient across the junction is determined based on a mathematical relationship between the temperature gradient, the change in thermovoltage with respect to distance and the change in biased current with respect to distance. Thermovoltage may be measured by nullifying a thermoelectric tunneling current with an applied voltage supply level. A piezoelectric actuator may modulate the probe, and thus the junction width, to vary thermovoltage and biased current across the junction. Lock-in amplifiers measure the derivatives of the thermovoltage and biased current modulated by varying junction width.

Dynamics of Josephson junction arrays

International Nuclear Information System (INIS)

Hadley, P.

1989-01-01

The dynamics of Josephson junction arrays is a topic that lies at the intersection of the fields of nonlinear dynamics and Josephson junction technology. The series arrays considered here consist of several rapidly oscillating Josephson junctions where each junction is coupled equally to every other junction. The purpose of this study is to understand phaselocking and other cooperative dynamics of this system. Previously, little was known about high dimensional nonlinear systems of this sort. Numerical simulations are used to study the dynamics of these arrays. Three distinct types of periodic solutions to the array equations were observed as well as period doubled and chaotic solutions. One of the periodic solutions is the symmetric, in-phase solution where all of the junctions oscillate identically. The other two periodic solutions are symmetry-broken solutions where all of the junction do not oscillate identically. The symmetry-broken solutions are highly degenerate. As many as (N - 1) stable solutions can coexist for an array of N junctions. Understanding the stability of these several solutions and the transitions among them is vital to the design of useful devices

Scarcity of Fresh Water Resources in the Ganges Delta of Bangladesh

Science.gov (United States)

Murshed, S. B.; Kaluarachchi, J. J.

2017-12-01

The Ganges Delta in Bangladesh is a classical example of water insecurity in a transboundary river basin where limitations in quantity, quality and timing of available water is producing disastrous conditions. Two opposite extreme water conditions, i.e., fresh water scarcity and floods are common in this region during dry and wet seasons, respectively. The purpose of this study is to manage fresh water requirement of people and environment considering the seasonal availability of surface water (SW) and ground water (GW). SW availability was analyzed by incoming stream flow including the effects of upstream water diversion, rainfall, temperature, evapotranspiration (ET). Flow duration curves (FDC), and rainfall and temperature elasticity are used to assess the change of incoming upstream flow. Groundwater data were collected from 285 piezometers and monitoring wells established by Bangladesh water development board. Variation of groundwater depth shows major withdrawals of GW are mostly concentrated in the north part of the study area. Irrigation is the largest sector of off-stream (irrigation, industrial and domestic) water use which occupies 82% SW and 17% GW of total water consumption. Although domestic water use is entirely depend on GW but arsenic pollution is limiting the GW use. FDC depicts a substantial difference between high flow threshold (20%) and low flow threshold (70%) in the Bangladesh part of Ganges River. A large variation of around 83% is observed for instream water volume between wet and dry seasons. The reduction of upstream fresh water flow increased the extent and intensity of salinity intrusion. Presently GW is also contaminated by saline water. This fresh water scarcity is reducing the livelihood options considerably and indirectly forcing population migration from the delta region. This study provides insight to the changes in hydrology and limitations to freshwater availability enabling better formulation of water resources management in

Tight junctions and human diseases.

Science.gov (United States)

Sawada, Norimasa; Murata, Masaki; Kikuchi, Keisuke; Osanai, Makoto; Tobioka, Hirotoshi; Kojima, Takashi; Chiba, Hideki

2003-09-01

Tight junctions are intercellular junctions adjacent to the apical end of the lateral membrane surface. They have two functions, the barrier (or gate) function and the fence function. The barrier function of tight junctions regulates the passage of ions, water, and various macromolecules, even of cancer cells, through paracellular spaces. The barrier function is thus relevant to edema, jaundice, diarrhea, and blood-borne metastasis. On the other hand, the fence function maintains cell polarity. In other words, tight junctions work as a fence to prevent intermixing of molecules in the apical membrane with those in the lateral membrane. This function is deeply involved in cancer cell biology, in terms of loss of cell polarity. Of the proteins comprising tight junctions, integral membrane proteins occludin, claudins, and JAMs have been recently discovered. Of these molecules, claudins are exclusively responsible for the formation of tight-junction strands and are connected with the actin cytoskeleton mediated by ZO-1. Thus, both functions of tight junctions are dependent on the integrity of the actin cytoskeleton as well as ATP. Mutations in the claudin14 and the claudin16 genes result in hereditary deafness and hereditary hypomagnesemia, respectively. Some pathogenic bacteria and viruses target and affect the tight-junction function, leading to diseases. In this review, the relationship between tight junctions and human diseases is summarized.

A single-gradient junction technique to replace multiple-junction shifts for craniospinal irradiation treatment

International Nuclear Information System (INIS)

Hadley, Austin; Ding, George X.

2014-01-01

Craniospinal irradiation (CSI) requires abutting fields at the cervical spine. Junction shifts are conventionally used to prevent setup error–induced overdosage/underdosage from occurring at the same location. This study compared the dosimetric differences at the cranial-spinal junction between a single-gradient junction technique and conventional multiple-junction shifts and evaluated the effect of setup errors on the dose distributions between both techniques for a treatment course and single fraction. Conventionally, 2 lateral brain fields and a posterior spine field(s) are used for CSI with weekly 1-cm junction shifts. We retrospectively replanned 4 CSI patients using a single-gradient junction between the lateral brain fields and the posterior spine field. The fields were extended to allow a minimum 3-cm field overlap. The dose gradient at the junction was achieved using dose painting and intensity-modulated radiation therapy planning. The effect of positioning setup errors on the dose distributions for both techniques was simulated by applying shifts of ± 3 and 5 mm. The resulting cervical spine doses across the field junction for both techniques were calculated and compared. Dose profiles were obtained for both a single fraction and entire treatment course to include the effects of the conventional weekly junction shifts. Compared with the conventional technique, the gradient-dose technique resulted in higher dose uniformity and conformity to the target volumes, lower organ at risk (OAR) mean and maximum doses, and diminished hot spots from systematic positioning errors over the course of treatment. Single-fraction hot and cold spots were improved for the gradient-dose technique. The single-gradient junction technique provides improved conformity, dose uniformity, diminished hot spots, lower OAR mean and maximum dose, and one plan for the entire treatment course, which reduces the potential human error associated with conventional 4-shifted plans

Risk and protective factors associated with gang-involved youth in Trinidad and Tobago Factores de riesgo y factores protectores asociados con la participación de los adolescentes en pandillas en Trinidad y Tabago

Directory of Open Access Journals (Sweden)

Charles M. Katz

2010-03-01

Full Text Available OBJECTIVES: To examine the prevalence of gang involvement, the risk and protective factors associated with gang involvement, and the association between gang involvement and exposure to multiple risk and protective factors among school-aged youth in Trinidad and Tobago. METHODS: A survey instrument was administered to 2 206 students enrolled in 22 high-risk, urban public schools, from March-June 2006. It measured 30 risk factors and 13 protective factors within four domains: community, school, family, and peer-individual, plus levels of alcohol/drug use and delinquency. RESULTS: About 7.7% of youth reported being a gang associate; 6.8%, a former gang member; and 6.2%, a current gang member. Gang involvement was associated with perceived availability of handguns, residential mobility, having parents who favor antisocial behavior, early initiation of antisocial behavior, intention to use drugs, having antisocial peers, and having peers who use drugs. Those with social skills, belief in moral order, and interactions with prosocial peers were significantly less likely to self-report gang membership. Additionally, the probability of gang involvement increased as the number of risk factors increased. CONCLUSIONS: Gang membership among public school youth is about as prevalent in Trinidad and Tobago as it is in the United States, Canada, and Western Europe, but further research is needed. Although risk factors associated with gang involvement were present in all four domains, peer-individual risk factors were disproportionately likely to be associated with gang status. The most effective gang prevention strategies might be those that focus on multiple risk factors, with an emphasis on peer-individual factors and promoting a "belief in moral order."OBJETIVOS: Examinar la prevalencia de la participación en pandillas, los factores de riesgo y los factores protectores asociados con la participación en pandillas, y la asociación entre la participaci

Point bars as stratigraphic traps for arsenic contamination in groundwater : Case study of the Ganges River, Bihar, India (abstract)

NARCIS (Netherlands)

Donselaar, M.E.; Bhatt, A.G.; Bruining, J.; Bose, N.; Ghosh, A.K.

2013-01-01

Arsenic-contaminated groundwater causes a wide-spread, serious health risk affecting millions of people worldwide. Focus of the research is the floodplain of the Ganges River in the State of Bihar (India) where groundwater is the principal source of drinking water and irrigation, and where the

Macroscopic quantum tunneling in Josephson tunnel junctions and Coulomb blockade in single small tunnel junctions

International Nuclear Information System (INIS)

Cleland, A.N.

1991-01-01

Experiments investigated the process of macroscopic quantum tunneling in a moderately-damped, resistively shunted, Josephson junction are described, followed by a discussion of experiments performed on very-small-capacitance normal-metal tunnel junctions. The experiments on the resistively-shunted Josephson junction were designed to investigate a quantum process, that of the tunneling of the Josephson-phase variable under a potential barrier, in a system in which dissipation plays a major role in the dynamics of motion. All the parameters of the junction were measured using the classical phenomena of thermal activation and resonant activation. Theoretical predictions are compared with the experimental results, showing good agreement with no adjustable parameters. The experiments on small-capacitance tunnel junctions extend the measurements on the large-area Josephson junctions from the region in which the phase variable has a fairly well-defined value, i.e. its wave function has a narrow width, to the region where its value is almost completely unknown. The charge on the junction becomes well-defined and is predicted to quantize the current through the junction, giving rise to the Coulomb blockade at low bias

Increasing gap junctional coupling: a tool for dissecting the role of gap junctions

DEFF Research Database (Denmark)

Axelsen, Lene Nygaard; Haugan, Ketil; Stahlhut, Martin

2007-01-01

Much of our current knowledge about the physiological and pathophysiological role of gap junctions is based on experiments where coupling has been reduced by either chemical agents or genetic modification. This has brought evidence that gap junctions are important in many physiological processes....... In a number of cases, gap junctions have been implicated in the initiation and progress of disease, and experimental uncoupling has been used to investigate the exact role of coupling. The inverse approach, i.e., to increase coupling, has become possible in recent years and represents a new way of testing...... the role of gap junctions. The aim of this review is to summarize the current knowledge obtained with agents that selectively increase gap junctional intercellular coupling. Two approaches will be reviewed: increasing coupling by the use of antiarrhythmic peptide and its synthetic analogs...

Junction detection and pathway selection

Science.gov (United States)

Peck, Alex N.; Lim, Willie Y.; Breul, Harry T.

1992-02-01

The ability to detect junctions and make choices among the possible pathways is important for autonomous navigation. In our script-based navigation approach where a journey is specified as a script of high-level instructions, actions are frequently referenced to junctions, e.g., `turn left at the intersection.' In order for the robot to carry out these kind of instructions, it must be able (1) to detect an intersection (i.e., an intersection of pathways), (2) know that there are several possible pathways it can take, and (3) pick the pathway consistent with the high level instruction. In this paper we describe our implementation of the ability to detect junctions in an indoor environment, such as corners, T-junctions and intersections, using sonar. Our approach uses a combination of partial scan of the local environment and recognition of sonar signatures of certain features of the junctions. In the case where the environment is known, we use additional sensor information (such as compass bearings) to help recognize the specific junction. In general, once a junction is detected and its type known, the number of possible pathways can be deduced and the correct pathway selected. Then the appropriate behavior for negotiating the junction is activated.

Supramolecular tunneling junctions

NARCIS (Netherlands)

Wimbush, K.S.

2012-01-01

In this study a variety of supramolecular tunneling junctions were created. The basis of these junctions was a self-assembled monolayer of heptathioether functionalized ß-cyclodextrin (ßCD) formed on an ultra-flat Au surface, i.e., the bottom electrode. This gave a well-defined hexagonally packed

Canaries in the coal mine: Interpersonal violence, gang violence, and violent extremism through a public health prevention lens.

Science.gov (United States)

Eisenman, David P; Flavahan, Louise

2017-08-01

This paper asks what programmes and policies for preventing violent extremism (also called 'countering violent extremism', or CVE) can learn from the public health violence prevention field. The general answer is that addressing violent extremism within the wider domain of public health violence prevention connects the effort to a relevant field of research, evidence-based policy and programming, and a broader population reach. This answer is reached by examining conceptual alignments between the two fields at both the case-level and the theoretical level. To address extremist violence within the wider reach of violence prevention, having a shared model is seen as a first step. The World Health Organization uses the social-ecological framework for assessing the risk and protective factors for violence and developing effective public-health based programmes. This study illustrates how this model has been used for gang violence prevention and explores overlaps between gang violence prevention and preventing violent extremism. Finally, it provides policy and programme recommendations to align CVE with public health violence prevention.

Phase diagrams of particles with dissimilar patches: X-junctions and Y-junctions

International Nuclear Information System (INIS)

Tavares, J M; Teixeira, P I C

2012-01-01

We use Wertheim’s first-order perturbation theory to investigate the phase behaviour and the structure of coexisting fluid phases for a model of patchy particles with dissimilar patches (two patches of type A and f B patches of type B). A patch of type α = {A,B} can bond to a patch of type β = {A,B} in a volume v αβ , thereby decreasing the internal energy by ε αβ . We analyse the range of model parameters where AB bonds, or Y-junctions, are energetically disfavoured (ε AB AA /2) but entropically favoured (v AB ≫ v αα ), and BB bonds, or X-junctions, are energetically favoured (ε BB > 0). We show that, for low values of ε BB /ε AA , the phase diagram has three different regions: (i) close to the critical temperature a low-density liquid composed of long chains and rich in Y-junctions coexists with a vapour of chains; (ii) at intermediate temperatures there is coexistence between a vapour of short chains and a liquid of very long chains with X- and Y-junctions; (iii) at low temperatures an ideal gas coexists with a high-density liquid with all possible AA and BB bonds formed. It is also shown that in region (i) the liquid binodal is reentrant (its density decreases with decreasing temperature) for the lower values of ε BB /ε AA . The existence of these three regions is a consequence of the competition between the formation of X- and Y-junctions: X-junctions are energetically favoured and thus dominate at low temperatures, whereas Y-junctions are entropically favoured and dominate at higher temperatures. (paper)

A Contemporary Challenge to State Sovereignty: Gangs and Other Illicit Transnational Criminal Organizations in Central America, El Salvador, Mexico, Jamaica, and Brazil

National Research Council Canada - National Science Library

Manwaring, Max G

2007-01-01

... Transnational Criminal Organizations (TCOs). In this new type of war, national security and sovereignty of affected countries is being impinged every day, and gangs illicit commercial motives are, in fact, becoming an ominous political agenda...

Common features of a vortex structure in long exponentially shaped Josephson junctions and Josephson junctions with inhomogeneities

International Nuclear Information System (INIS)

Boyadjiev, T.L.; Semerdjieva, E.G.; Shukrinov, Yu.M.

2007-01-01

We study the vortex structure in three different models of the long Josephson junction: the exponentially shaped Josephson junction and the Josephson junctions with the resistor and the shunt inhomogeneities in the barrier layer. For these three models the critical curves 'critical current-magnetic field' are numerically constructed. We develop the idea of the equivalence of the exponentially shaped Josephson junction and the rectangular junction with the distributed inhomogeneity and demonstrate that at some parameters of the shunt and the resistor inhomogeneities in the ends of the junction the corresponding critical curves are very close to the exponentially shaped one

Seasonal variations in terrestrial gamma radiation along river Ganges and implications to public health risk

International Nuclear Information System (INIS)

Sharma, P.; Meher, P.K.; Mishra, K.P.

2016-01-01

Measurement of exposure to terrestrial gamma radiation dose and determination of associated health hazard at river bank is of major importance due to the increasing tourism, bathing festivals and mythological beliefs. Present study was focused on measurement of absorbed dose rates as function of seasonal variation at designated locations along Ganges river in India. Portable dosimeter (plastic scintillation counter) was used for the measurement of absorbed dose rates. Subsequently, annual effective dose (AED) and excess lifetime cancer risk (ELCR) were calculated by the standard procedure. Results showed absorbed dose rates for Pre-monsoon ranged from 89.7 ± 4.03 to 115.0 ± 7.81 nSv/h with an average of 105.54 nSv/h. Post-monsoon measurements yielded values from 81.0 ± 7.00 to 105.6 ± 5.75 nSv/h with an average value of 90.8 nSv/h. Calculated average AED for Pre-monsoon period was found to be 0.13 mSv/y. Whereas, 0.11 mSv/y was the AED for the post-monsoon period. Furthermore, the calculated average ELCR values for pre-monsoon and post-monsoon were found to be 0.488 × 10 -3 and 0.418 × 10 -3 , respectively. This study reports significant seasonal variations in the terrestrial gamma radiation doses along the long stretch of Ganges river. (author)

Behavior of tight-junction, adherens-junction and cell polarity proteins during HNF-4α-induced epithelial polarization

International Nuclear Information System (INIS)

Satohisa, Seiro; Chiba, Hideki; Osanai, Makoto; Ohno, Shigeo; Kojima, Takashi; Saito, Tsuyoshi; Sawada, Norimasa

2005-01-01

We previously reported that expression of tight-junction molecules occludin, claudin-6 and claudin-7, as well as establishment of epithelial polarity, was triggered in mouse F9 cells expressing hepatocyte nuclear factor (HNF)-4α [H. Chiba, T. Gotoh, T. Kojima, S. Satohisa, K. Kikuchi, M. Osanai, N. Sawada. Hepatocyte nuclear factor (HNF)-4α triggers formation of functional tight junctions and establishment of polarized epithelial morphology in F9 embryonal carcinoma cells, Exp. Cell Res. 286 (2003) 288-297]. Using these cells, we examined in the present study behavior of tight-junction, adherens-junction and cell polarity proteins and elucidated the molecular mechanism behind HNF-4α-initiated junction formation and epithelial polarization. We herein show that not only ZO-1 and ZO-2, but also ZO-3, junctional adhesion molecule (JAM)-B, JAM-C and cell polarity proteins PAR-3, PAR-6 and atypical protein kinase C (aPKC) accumulate at primordial adherens junctions in undifferentiated F9 cells. In contrast, CRB3, Pals1 and PATJ appeared to exhibit distinct subcellular localization in immature cells. Induced expression of HNF-4α led to translocation of these tight-junction and cell polarity proteins to beltlike tight junctions, where occludin, claudin-6 and claudin-7 were assembled, in differentiated cells. Interestingly, PAR-6, aPKC, CRB3 and Pals1, but not PAR-3 or PATJ, were also concentrated on the apical membranes in differentiated cells. These findings indicate that HNF-4α provokes not only expression of tight-junction adhesion molecules, but also modulation of subcellular distribution of junction and cell polarity proteins, resulting in junction formation and epithelial polarization

Flexible 2D layered material junctions

Science.gov (United States)

Balabai, R.; Solomenko, A.

2018-03-01

Within the framework of the methods of the electron density functional and the ab initio pseudopotential, we have obtained the valence electron density spatial distribution, the densities of electron states, the widths of band gaps, the charges on combined regions, and the Coulomb potentials for graphene-based flexible 2D layered junctions, using author program complex. It is determined that the bending of the 2D layered junctions on the angle α leads to changes in the electronic properties of these junctions. In the graphene/graphane junction, there is clear charge redistribution with different signs in the regions of junctions. The presence in the heterojunctions of charge regions with different signs leads to the formation of potential barriers. The greatest potential jump is in the graphene/fluorographene junction. The greatest value of the band gap width is in the graphene/graphane junction.

Model study of the impacts of future climate change on the hydrology of Ganges-Brahmaputra-Meghna (GBM) basin

Science.gov (United States)

Masood, M.; Yeh, P. J.-F.; Hanasaki, N.; Takeuchi, K.

2014-06-01

The intensity, duration, and geographic extent of floods in Bangladesh mostly depend on the combined influences of three river systems, Ganges, Brahmaputra and Meghna (GBM). In addition, climate change is likely to have significant effects on the hydrology and water resources of the GBM basins and might ultimately lead to more serious floods in Bangladesh. However, the assessment of climate change impacts on basin-scale hydrology by using well-constrained hydrologic modelling has rarely been conducted for GBM basins due to the lack of data for model calibration and validation. In this study, a macro-scale hydrologic model H08 has been applied regionally over the basin at a relatively fine grid resolution (10 km) by integrating the fine-resolution (~0.5 km) DEM data for accurate river networks delineation. The model has been calibrated via analyzing model parameter sensitivity and validated based on a long-term observed daily streamflow data. The impact of climate change on not only the runoff, but also the basin-scale hydrology including evapotranspiration, soil moisture and net radiation have been assessed in this study through three time-slice experiments; present-day (1979-2003), near-future (2015-2039) and far-future (2075-2099) periods. Results shows that, by the end of 21st century (a) the entire GBM basin is projected to be warmed by ~3°C (b) the changes of mean precipitation are projected to be +14.0, +10.4, and +15.2%, and the changes of mean runoff to be +14, +15, and +18% in the Brahmaputra, Ganges and Meghna basin respectively (c) evapotranspiration is predicted to increase significantly for the entire GBM basins (Brahmaputra: +14.4%, Ganges: +9.4%, Meghna: +8.8%) due to increased net radiation (Brahmaputra: +6%, Ganges: +5.9%, Meghna: +3.3%) as well as warmer air temperature. Changes of hydrologic variables will be larger in dry season (November-April) than that in wet season (May-October). Amongst three basins, Meghna shows the largest hydrological

Epidemiological criminology: drug use among African American gang members.

Science.gov (United States)

Lanier, Mark M; Pack, Robert P; Akers, Timothy A

2010-01-01

Epidemiological methods and public health theories can be tied to theories of crime and delinquency and used to create evidence-based policy. Interdisciplinary theoretical approaches to existing, and emerging, public health and criminal justice problems hold great promise. Differential association theory postulates that close association with delinquent peers leads to an increase in deviant activities such as illicit drug use. Social cognitive theory postulates that health behavior change is driven by the interaction of (a) cognitive states that support a health outcome, (b) the social and contextual environment, (c) and individual action. Combined, these theories can be applied to drug eradication programs as well as other health and crime issues. Focus groups and interviews were performed to identify rates of illicit substance use among incarcerated African American adolescent male gang members and nongang members. The policy recommendations illustrate the convergence of criminological and epidemiological theory under the new paradigm of epidemiological criminology or ''EpiCrim.''

The Dissolution of Double Holliday Junctions

DEFF Research Database (Denmark)

Bizard, Anna H; Hickson, Ian D

2014-01-01

as "double Holliday junction dissolution." This reaction requires the cooperative action of a so-called "dissolvasome" comprising a Holliday junction branch migration enzyme (Sgs1/BLM RecQ helicase) and a type IA topoisomerase (Top3/TopoIIIα) in complex with its OB (oligonucleotide/oligosaccharide binding......Double Holliday junctions (dHJS) are important intermediates of homologous recombination. The separate junctions can each be cleaved by DNA structure-selective endonucleases known as Holliday junction resolvases. Alternatively, double Holliday junctions can be processed by a reaction known......) fold containing accessory factor (Rmi1). This review details our current knowledge of the dissolution process and the players involved in catalyzing this mechanistically complex means of completing homologous recombination reactions....

Spatial and seasonal responses of precipitation in the Ganges and Brahmaputra river basins to ENSO and Indian Ocean dipole modes: implications for flooding and drought

Science.gov (United States)

Pervez, M. S.; Henebry, G. M.

2014-02-01

We evaluated the spatial and temporal responses of precipitation in the basins as modulated by the El Niño Southern Oscillation (ENSO) and Indian Ocean (IO) dipole modes using observed precipitation records at 43 stations across the Ganges and Brahmaputra basins from 1982 to 2010. Daily observed precipitation records were extracted from Global Surface Summary of the Day dataset and spatial and monthly anomalies were computed. The anomalies were averaged for the years influenced by climate modes combinations. Occurrences of El Niño alone significantly reduced (60% and 88% of baseline in the Ganges and Brahmaputra basins, respectively) precipitation during the monsoon months in the northwestern and central Ganges basin and across the Brahmaputra basin. In contrast, co-occurrence of La Niña and a positive IO dipole mode significantly enhanced (135% and 160% of baseline, respectively) precipitation across both basins. During the co-occurrence of neutral phases in both climate modes (occurring 13 out of 28 yr), precipitation remained below average to average in the agriculturally extensive areas of Haryana, Uttar Pradesh, Bihar, eastern Nepal, and the Rajshahi district in Bangladesh in the Ganges basin and northern Bangladesh, Meghalaya, Assam, and Arunachal Pradesh in the Brahmaputra basin. This pattern implies that a regular water deficit is likely in these areas with implications for the agriculture sector due to its reliance on consistent rainfall for successful production. Major flooding and drought occurred as a consequence of the interactive effects of the ENSO and IO dipole modes, with the sole exception of extreme precipitation and flooding during El Niño events. This observational analysis will facilitate well informed decision making in minimizing natural hazard risks and climate impacts on agriculture, and supports development of strategies ensuring optimized use of water resources in best management practice under changing climate.

Quantum Junction Solar Cells

KAUST Repository

Tang, Jiang

2012-09-12

Colloidal quantum dot solids combine convenient solution-processing with quantum size effect tuning, offering avenues to high-efficiency multijunction cells based on a single materials synthesis and processing platform. The highest-performing colloidal quantum dot rectifying devices reported to date have relied on a junction between a quantum-tuned absorber and a bulk material (e.g., TiO 2); however, quantum tuning of the absorber then requires complete redesign of the bulk acceptor, compromising the benefits of facile quantum tuning. Here we report rectifying junctions constructed entirely using inherently band-aligned quantum-tuned materials. Realizing these quantum junction diodes relied upon the creation of an n-type quantum dot solid having a clean bandgap. We combine stable, chemically compatible, high-performance n-type and p-type materials to create the first quantum junction solar cells. We present a family of photovoltaic devices having widely tuned bandgaps of 0.6-1.6 eV that excel where conventional quantum-to-bulk devices fail to perform. Devices having optimal single-junction bandgaps exhibit certified AM1.5 solar power conversion efficiencies of 5.4%. Control over doping in quantum solids, and the successful integration of these materials to form stable quantum junctions, offers a powerful new degree of freedom to colloidal quantum dot optoelectronics. © 2012 American Chemical Society.

Molecular electronic junction transport

DEFF Research Database (Denmark)

Solomon, Gemma C.; Herrmann, Carmen; Ratner, Mark

2012-01-01

Whenasinglemolecule,oracollectionofmolecules,isplacedbetween two electrodes and voltage is applied, one has a molecular transport junction. We discuss such junctions, their properties, their description, and some of their applications. The discussion is qualitative rather than quantitative, and f...

Gap junctions and motor behavior

DEFF Research Database (Denmark)

Kiehn, Ole; Tresch, Matthew C.

2002-01-01

The production of any motor behavior requires coordinated activity in motor neurons and premotor networks. In vertebrates, this coordination is often assumed to take place through chemical synapses. Here we review recent data suggesting that electrical gap-junction coupling plays an important role...... in coordinating and generating motor outputs in embryonic and early postnatal life. Considering the recent demonstration of a prevalent expression of gap-junction proteins and gap-junction structures in the adult mammalian spinal cord, we suggest that neuronal gap-junction coupling might also contribute...... to the production of motor behavior in adult mammals....

Ferromagnetic Josephson Junctions for Cryogenic Memory

Science.gov (United States)

Niedzielski, Bethany M.; Gingrich, Eric C.; Khasawneh, Mazin A.; Loloee, Reza; Pratt, William P., Jr.; Birge, Norman O.

2015-03-01

Josephson junctions containing ferromagnetic materials are of interest for both scientific and technological purposes. In principle, either the amplitude of the critical current or superconducting phase shift across the junction can be controlled by the relative magnetization directions of the ferromagnetic layers in the junction. Our approach concentrates on phase control utilizing two junctions in a SQUID geometry. We will report on efforts to control the phase of junctions carrying either spin-singlet or spin-triplet supercurrent for cryogenic memory applications. Supported by Northorp Grumman Corporation and by IARPA under SPAWAR Contract N66001-12-C-2017.

Towards a National Gang Strategy: A Meta-Policy Analysis of Leadership, Learning, and Organizational Change within the Law Enforcement Context

Science.gov (United States)

Richards, Maurice V.

2010-01-01

This study examines the process of change within law enforcement, focusing on the leadership, learning, and organizational change required to reduce crime, violence, and social disruption caused by criminal street gangs. The study tests the viability, results, and implications of a new policing model, the trans-jurisdictional task force, through…

Electronic noise of superconducting tunnel junction detectors

International Nuclear Information System (INIS)

Jochum, J.; Kraus, H.; Gutsche, M.; Kemmather, B.; Feilitzsch, F. v.; Moessbauer, R.L.

1994-01-01

The optimal signal to noise ratio for detectors based on superconducting tunnel junctions is calculated and compared for the cases of a detector consisting of one single tunnel junction, as well as of series and of parallel connections of such tunnel junctions. The influence of 1 / f noise and its dependence on the dynamical resistance of tunnel junctions is discussed quantitatively. A single tunnel junction yields the minimum equivalent noise charge. Such a tunnel junction exhibits the best signal to noise ratio if the signal charge is independent of detector size. In case, signal charge increases with detector size, a parallel or a series connection of tunnel junctions would provide the optimum signal to noise ratio. The equivalent noise charge and the respective signal to noise ratio are deduced as functions of tunnel junction parameters such as tunneling time, quasiparticle lifetime, etc. (orig.)

Atomic-scaled characterization of graphene PN junctions

Science.gov (United States)

Zhou, Xiaodong; Wang, Dennis; Dadgar, Ali; Agnihotri, Pratik; Lee, Ji Ung; Reuter, Mark C.; Ross, Frances M.; Pasupathy, Abhay N.

Graphene p-n junctions are essential devices for studying relativistic Klein tunneling and the Veselago lensing effect in graphene. We have successfully fabricated graphene p-n junctions using both lithographically pre-patterned substrates and the stacking of vertical heterostructures. We then use our 4-probe STM system to characterize the junctions. The ability to carry out scanning electron microscopy (SEM) in our STM instrument is essential for us to locate and measure the junction interface. We obtain both the topography and dI/dV spectra at the junction area, from which we track the shift of the graphene chemical potential with position across the junction interface. This allows us to directly measure the spatial width and roughness of the junction and its potential barrier height. We will compare the junction properties of devices fabricated by the aforementioned two methods and discuss their effects on the performance as a Veselago lens.

Stability of large-area molecular junctions

NARCIS (Netherlands)

Akkerman, Hylke B.; Kronemeijer, Auke J.; Harkema, Jan; van Hal, Paul A.; Smits, Edsger C. P.; de Leeuw, Dago M.; Blom, Paul W. M.

The stability of molecular junctions is crucial for any application of molecular electronics. Degradation of molecular junctions when exposed to ambient conditions is regularly observed. In this report the stability of large-area molecular junctions under ambient conditions for more than two years

Superconducting flux qubits with π-junctions

International Nuclear Information System (INIS)

Shcherbakova, Anastasia

2014-01-01

In this thesis, we present a fabrication technology of Al/AlO x /Al Josephson junctions on Nb pads. The described technology gives the possibility of combining a variety of Nb-based superconducting circuits, like pi-junction phase-shifters with sub-micron Al/AlO x /Al junctions. Using this approach, we fabricated hybrid Nb/Al flux qubits with and without the SFS-junctions and studied dispersive magnetic field response of these qubits as well as their spectroscopy characteristics.

Resonance Transport of Graphene Nanoribbon T-Shaped Junctions

International Nuclear Information System (INIS)

Xiao-Lan, Kong; Yong-Jian, Xiong

2010-01-01

We investigate the transport properties of T-shaped junctions composed of armchair graphene nanoribbons of different widths. Three types of junction geometries are considered. The junction conductance strongly depends on the atomic features of the junction geometry. When the shoulders of the junction have zigzag type edges, sharp conductance resonances usually appear in the low energy region around the Dirac point, and a conductance gap emerges. When the shoulders of the junction have armchair type edges, the conductance resonance behavior is weakened significantly, and the metal-metal-metal junction structures show semimetallic behaviors. The contact resistance also changes notably due to the various interface geometries of the junction

Construction of pipelines on marshlands during summer months with the aid of gang assembly platforms

Energy Technology Data Exchange (ETDEWEB)

Kovalev, E P; Girshovich, I I

1979-05-01

Because the massive size of conventional pipeline-construction equipment limits its use in swampy areas to winter months, the USSR's SKB Gazstroimashina developed a new system to allow year-round construction activity. The equipment consists of five mobile platforms arranged in series along the pipeline to spread out the load for a lower specific ground pressure than exerted by conventional equipment. Platforms perform the successive functions of emplacement of the pipe lengths, end preparation, welding, cleanup, and insulation. So far, two sets of gang-assembly platforms have been built and are being field-tested.

Josephson junctions with ferromagnetic interlayer

International Nuclear Information System (INIS)

Wild, Georg Hermann

2012-01-01

We report on the fabrication of superconductor/insulator/ferromagnetic metal/superconductor (Nb/AlO x /Pd 0.82 Ni 0.18 /Nb) Josephson junctions (SIFS JJs) with high critical current densities, large normal resistance times area products, and high quality factors. For these junctions, a transition from 0- to π-coupling is observed for a thickness d F =6 nm of the ferromagnetic Pd 0.82 Ni 0.18 interlayer. The magnetic field dependence of the critical current of the junctions demonstrates good spatial homogeneity of the tunneling barrier and ferromagnetic interlayer. Magnetic characterization shows that the Pd 0.82 Ni 0.18 has an out-of-plane anisotropy and large saturation magnetization indicating negligible dead layers at the interfaces. A careful analysis of Fiske modes up to about 400 GHz provides valuable information on the junction quality factor and the relevant damping mechanisms. Whereas losses due to quasiparticle tunneling dominate at low frequencies, at high frequencies the damping is explained by the finite surface resistance of the junction electrodes. High quality factors of up to 30 around 200 GHz have been achieved. They allow to study the junction dynamics, in particular the switching probability from the zero-voltage into the voltage state with and without microwave irradiation. The experiments with microwave irradiation are well explained within semi-classical models and numerical simulations. In contrast, at mK temperature the switching dynamics without applied microwaves clearly shows secondary quantum effects. Here, we could observe for the first time macroscopic quantum tunneling in Josephson junctions with a ferromagnetic interlayer. This observation excludes fluctuations of the critical current as a consequence of an unstable magnetic domain structure of the ferromagnetic interlayer and affirms the suitability of SIFS Josephson junctions for quantum information processing.

Josephson junctions with ferromagnetic interlayer

Energy Technology Data Exchange (ETDEWEB)

Wild, Georg Hermann

2012-03-04

We report on the fabrication of superconductor/insulator/ferromagnetic metal/superconductor (Nb/AlO{sub x}/Pd{sub 0.82}Ni{sub 0.18}/Nb) Josephson junctions (SIFS JJs) with high critical current densities, large normal resistance times area products, and high quality factors. For these junctions, a transition from 0- to {pi}-coupling is observed for a thickness d{sub F}=6 nm of the ferromagnetic Pd{sub 0.82}Ni{sub 0.18} interlayer. The magnetic field dependence of the critical current of the junctions demonstrates good spatial homogeneity of the tunneling barrier and ferromagnetic interlayer. Magnetic characterization shows that the Pd{sub 0.82}Ni{sub 0.18} has an out-of-plane anisotropy and large saturation magnetization indicating negligible dead layers at the interfaces. A careful analysis of Fiske modes up to about 400 GHz provides valuable information on the junction quality factor and the relevant damping mechanisms. Whereas losses due to quasiparticle tunneling dominate at low frequencies, at high frequencies the damping is explained by the finite surface resistance of the junction electrodes. High quality factors of up to 30 around 200 GHz have been achieved. They allow to study the junction dynamics, in particular the switching probability from the zero-voltage into the voltage state with and without microwave irradiation. The experiments with microwave irradiation are well explained within semi-classical models and numerical simulations. In contrast, at mK temperature the switching dynamics without applied microwaves clearly shows secondary quantum effects. Here, we could observe for the first time macroscopic quantum tunneling in Josephson junctions with a ferromagnetic interlayer. This observation excludes fluctuations of the critical current as a consequence of an unstable magnetic domain structure of the ferromagnetic interlayer and affirms the suitability of SIFS Josephson junctions for quantum information processing.

A survey of perfluorinated compounds in surface water and biota including dolphins from the Ganges River and in other waterbodies in India

Digital Repository Service at National Institute of Oceanography (India)

Yeung, L.W.Y.; Yamashita, N.; Taniyasu, S.; Lam, P.K.S.; Sinha, R; Borole, D.V.; Kannan, K.

and biomagnifications factors of PFCs were estimated in the Ganges River basin food web. The highest concentration of PFOA, 23.1 ng L sup(-1), was found in untreated sewage samples. Overall, concentrations of PFCs of water and biological samples from India are lower...

Electron optics with ballistic graphene junctions

Science.gov (United States)

Chen, Shaowen

Electrons transmitted across a ballistic semiconductor junction undergo refraction, analogous to light rays across an optical boundary. A pn junction theoretically provides the equivalent of a negative index medium, enabling novel electron optics such as negative refraction and perfect (Veselago) lensing. In graphene, the linear dispersion and zero-gap bandstructure admit highly transparent pn junctions by simple electrostatic gating, which cannot be achieved in conventional semiconductors. Robust demonstration of these effects, however, has not been forthcoming. Here we employ transverse magnetic focusing to probe propagation across an electrostatically defined graphene junction. We find perfect agreement with the predicted Snell's law for electrons, including observation of both positive and negative refraction. Resonant transmission across the pn junction provides a direct measurement of the angle dependent transmission coefficient, and we demonstrate good agreement with theory. Comparing experimental data with simulation reveals the crucial role played by the effective junction width, providing guidance for future device design. Efforts toward sharper pn junction and possibility of zero field Veselago lensing will also be discussed. This work is supported by the Semiconductor Research Corporations NRI Center for Institute for Nanoelectronics Discovery and Exploration (INDEX).

Peltier cooling in molecular junctions

Science.gov (United States)

Cui, Longji; Miao, Ruijiao; Wang, Kun; Thompson, Dakotah; Zotti, Linda Angela; Cuevas, Juan Carlos; Meyhofer, Edgar; Reddy, Pramod

2018-02-01

The study of thermoelectricity in molecular junctions is of fundamental interest for the development of various technologies including cooling (refrigeration) and heat-to-electricity conversion1-4. Recent experimental progress in probing the thermopower (Seebeck effect) of molecular junctions5-9 has enabled studies of the relationship between thermoelectricity and molecular structure10,11. However, observations of Peltier cooling in molecular junctions—a critical step for establishing molecular-based refrigeration—have remained inaccessible. Here, we report direct experimental observations of Peltier cooling in molecular junctions. By integrating conducting-probe atomic force microscopy12,13 with custom-fabricated picowatt-resolution calorimetric microdevices, we created an experimental platform that enables the unified characterization of electrical, thermoelectric and energy dissipation characteristics of molecular junctions. Using this platform, we studied gold junctions with prototypical molecules (Au-biphenyl-4,4'-dithiol-Au, Au-terphenyl-4,4''-dithiol-Au and Au-4,4'-bipyridine-Au) and revealed the relationship between heating or cooling and charge transmission characteristics. Our experimental conclusions are supported by self-energy-corrected density functional theory calculations. We expect these advances to stimulate studies of both thermal and thermoelectric transport in molecular junctions where the possibility of extraordinarily efficient energy conversion has been theoretically predicted2-4,14.

Dynamics of pi-junction interferometer circuits

DEFF Research Database (Denmark)

Kornkev, V.K.; Mozhaev, P.B.; Borisenko, I.V.

2002-01-01

The pi-junction superconducting circuit dynamics was studied by means of numerical simulation technique. Parallel arrays consisting of Josephson junctions of both 0- and pi-type were studied as a model of high-T-c grain-boundary Josephson junction. The array dynamics and the critical current depe...

Geodynamical simulation of the RRF triple junction

Science.gov (United States)

Wang, Z.; Wei, D.; Liu, M.; Shi, Y.; Wang, S.

2017-12-01

Triple junction is the point at which three plate boundaries meet. Three plates at the triple junction form a complex geological tectonics, which is a natural laboratory to study the interactions of plates. This work studies a special triple junction, the oceanic transform fault intersects the collinear ridges with different-spreading rates, which is free of influence of ridge-transform faults and nearby hotspots. First, we build 3-D numerical model of this triple junction used to calculate the stead-state velocity and temperature fields resulting from advective and conductive heat transfer. We discuss in detail the influence of the velocity and temperature fields of the triple junction from viscosity, spreading rate of the ridge. The two sides of the oceanic transform fault are different sensitivities to the two factors. And, the influence of the velocity mainly occurs within 200km of the triple junction. Then, we modify the model by adding a ridge-transform fault to above model and directly use the velocity structure of the Macquarie triple junction. The simulation results show that the temperature at both sides of the oceanic transform fault decreases gradually from the triple junction, but the temperature difference between the two sides is a constant about 200°. And, there is little effect of upwelling velocity away from the triple junction 100km. The model results are compared with observational data. The heat flux and thermal topography along the oceanic transform fault of this model are consistent with the observed data of the Macquarie triple junction. The earthquakes are strike slip distributed along the oceanic transform fault. Their depths are also consistent with the zone of maximum shear stress. This work can help us to understand the interactions of plates of triple junctions and help us with the foundation for the future study of triple junctions.

Hydroclimatic sustainability assessment of changing climate on cholera in the Ganges-Brahmaputra basin

Science.gov (United States)

Nasr-Azadani, Fariborz; Khan, Rakibul; Rahimikollu, Javad; Unnikrishnan, Avinash; Akanda, Ali; Alam, Munirul; Huq, Anwar; Jutla, Antarpreet; Colwell, Rita

2017-10-01

The association of cholera and climate has been extensively documented. However, determining the effects of changing climate on the occurrence of disease remains a challenge. Bimodal peaks of cholera in Bengal Delta are hypothesized to be linked to asymmetric flow of the Ganges and Brahmaputra rivers. Spring cholera is related to intrusion of bacteria-laden coastal seawater during low flow seasons, while autumn cholera results from cross-contamination of water resources when high flows in the rivers cause massive inundation. Coarse resolution of General Circulation Model (GCM) output (usually at 100 - 300 km)cannot be used to evaluate variability at the local scale(10-20 km),hence the goal of this study was to develop a framework that could be used to understand impacts of climate change on occurrence of cholera. Instead of a traditional approach of downscaling precipitation, streamflow of the two rivers was directly linked to GCM outputs, achieving reasonable accuracy (R2 = 0.89 for the Ganges and R2 = 0.91 for the Brahmaputra)using machine learning algorithms (Support Vector Regression-Particle Swarm Optimization). Copula methods were used to determine probabilistic risks of cholera under several discharge conditions. Key results, using model outputs from ECHAM5, GFDL, andHadCM3for A1B and A2 scenarios, suggest that the combined low flow of the two rivers may increase in the future, with high flows increasing for first half of this century, decreasing thereafter. Spring and autumn cholera, assuming societal conditions remain constant e.g., at the current rate, may decrease. However significant shifts were noted in the magnitude of river discharge suggesting that cholera dynamics of the delta may well demonstrate an uncertain predictable pattern of occurrence over the next century.

Loss models for long Josephson junctions

DEFF Research Database (Denmark)

Olsen, O. H.; Samuelsen, Mogens Rugholm

1984-01-01

A general model for loss mechanisms in long Josephson junctions is presented. An expression for the zero-field step is found for a junction of overlap type by means of a perturbation method. Comparison between analytic solution and perturbation result shows good agreement.......A general model for loss mechanisms in long Josephson junctions is presented. An expression for the zero-field step is found for a junction of overlap type by means of a perturbation method. Comparison between analytic solution and perturbation result shows good agreement....

Dynamics of the Josephson multi-junction system with junctions characterized by non-sinusoidal current - phase relationship

International Nuclear Information System (INIS)

Abal'osheva, I.; Lewandowski, S.J.

2004-01-01

It is shown that the inclusion of junctions characterized by non-sinusoidal current - phase relationship in the systems composed of multiple Josephson junctions - results in the appearance of additional system phase states. Numerical simulations and stability considerations confirm that those phase states can be realized in practice. Moreover, spontaneous formation of the grain boundary junctions in high-T c superconductors with non-trivial current-phase relations due to the d-wave symmetry of the order parameter is probable. Switching between the phase states of multiple grain boundary junction systems can lead to additional 1/f noise in high-T c superconductors. (author)

Theoretical and experimental investigations on synchronization in many-junction arrays of HTSC Josephson junctions. Final report

International Nuclear Information System (INIS)

Seidel, P.; Heinz, E.; Pfuch, A.; Machalett, F.; Krech, W.; Basler, M.

1996-06-01

Different many-junction arrays of Josephson junctions were studied theoretically to analyse the mechanisms of synchronization, the influence of internal and external parameters and the maximal allowed spread of parameters for the single junctions. Concepts to realize arrays using standard high-T c superconductor technology were created, e.g. the new arrangement of multijunction superconducting loops (MSL). First experimental results show the relevance of this concept. Intrinsic one-dimensional arrays in thin film technology were prepared as mesas out of Bi or Tl 2212 films. to characterize HTSC Josephson junctions methods based on the analysis of microwave-induced steps were developed. (orig.) [de

Single P-N junction tandem photovoltaic device

Science.gov (United States)

Walukiewicz, Wladyslaw [Kensington, CA; Ager, III, Joel W.; Yu, Kin Man [Lafayette, CA

2011-10-18

A single P-N junction solar cell is provided having two depletion regions for charge separation while allowing the electrons and holes to recombine such that the voltages associated with both depletion regions of the solar cell will add together. The single p-n junction solar cell includes an alloy of either InGaN or InAlN formed on one side of the P-N junction with Si formed on the other side in order to produce characteristics of a two junction (2J) tandem solar cell through only a single P-N junction. A single P-N junction solar cell having tandem solar cell characteristics will achieve power conversion efficiencies exceeding 30%.

The anatomical locus of T-junction processing.

Science.gov (United States)

Schirillo, James A

2009-07-01

Inhomogeneous surrounds can produce either asymmetrical or symmetrical increment/decrement induction by orienting T-junctions to selectively group a test patch with surrounding regions [Melfi, T., & Schirillo, J. (2000). T-junctions in inhomogeneous surrounds. Vision Research, 40, 3735-3741]. The current experiments aimed to determine where T-junctions are processed by presenting each eye with a different image so that T-junctions exist only in the fused percept. Only minor differences were found between retinal and cortical versus cortical-only conditions, indicating that T-junctions are processed cortically.

Mixing in T-junctions

NARCIS (Netherlands)

Kok, Jacobus B.W.; van der Wal, S.

1996-01-01

The transport processes that are involved in the mixing of two gases in a T-junction mixer are investigated. The turbulent flow field is calculated for the T-junction with the k- turbulence model by FLOW3D. In the mathematical model the transport of species is described with a mixture fraction

Effect of junction configurations on microdroplet formation in a T-junction microchannel

Science.gov (United States)

Lih, F. L.; Miao, J. M.

2015-03-01

This study investigates the dynamic formation process of water microdroplets in a silicon oil flow in a T-junction microchannel. Segmented water microdroplets are formed at the junction when the water flow is perpendicularly injected into the silicon oil flow in a straight rectangular microchannel. This study further presents the effects of the water flow inlet geometry on hydrodynamic characteristics of water microdroplet formation. A numerical multiphase volume of fluid (VOF) scheme is coupled to solve the unsteady three-dimensional laminar Navier-Stokes equations to depict the droplet formation phenomena at the junction. Predicted results on the length and generated frequency of the microdroplets agree well with experimental results in a T-junction microchannel with straight and flat inlets (the base model) for both fluid flows. Empirical correlations are reported between the volumetric flow ratio and the dimensionless microdroplet length or dimensionless frequency of droplet generation at a fixed capillary number of 4.7 · 10-3. The results of this study indicate a reduction in the droplet length of approximately 21% if the straight inlet for the water flow is modified to a downstream sudden contraction inlet for the water flow.

Poster - Thur Eve - 57: Craniospinal irradiation with jagged-junction IMRT approach without beam edge matching for field junctions.

Science.gov (United States)

Cao, F; Ramaseshan, R; Corns, R; Harrop, S; Nuraney, N; Steiner, P; Aldridge, S; Liu, M; Carolan, H; Agranovich, A; Karva, A

2012-07-01

Craniospinal irradiation were traditionally treated the central nervous system using two or three adjacent field sets. A intensity-modulated radiotherapy (IMRT) plan (Jagged-Junction IMRT) which overcomes problems associated with field junctions and beam edge matching, improves planning and treatment setup efficiencies with homogenous target dose distribution was developed. Jagged-Junction IMRT was retrospectively planned on three patients with prescription of 36 Gy in 20 fractions and compared to conventional treatment plans. Planning target volume (PTV) included the whole brain and spinal canal to the S3 vertebral level. The plan employed three field sets, each with a unique isocentre. One field set with seven fields treated the cranium. Two field sets treated the spine, each set using three fields. Fields from adjacent sets were overlapped and the optimization process smoothly integrated the dose inside the overlapped junction. For the Jagged-Junction IMRT plans vs conventional technique, average homogeneity index equaled 0.08±0.01 vs 0.12±0.02, and conformity number equaled 0.79±0.01 vs 0.47±0.12. The 95% isodose surface covered (99.5±0.3)% of the PTV vs (98.1±2.0)%. Both Jagged-Junction IMRT plans and the conventional plans had good sparing of the organs at risk. Jagged-Junction IMRT planning provided good dose homogeneity and conformity to the target while maintaining a low dose to the organs at risk. Jagged-Junction IMRT optimization smoothly distributed dose in the junction between field sets. Since there was no beam matching, this treatment technique is less likely to produce hot or cold spots at the junction in contrast to conventional techniques. © 2012 American Association of Physicists in Medicine.

Projections of the Ganges-Brahmaputra precipitation: downscaled from GCM predictors

Science.gov (United States)

Pervez, Md Shahriar; Henebry, Geoffrey M.

2014-01-01

Downscaling Global Climate Model (GCM) projections of future climate is critical for impact studies. Downscaling enables use of GCM experiments for regional scale impact studies by generating regionally specific forecasts connecting global scale predictions and regional scale dynamics. We employed the Statistical Downscaling Model (SDSM) to downscale 21st century precipitation for two data-sparse hydrologically challenging river basins in South Asia—the Ganges and the Brahmaputra. We used CGCM3.1 by Canadian Center for Climate Modeling and Analysis version 3.1 predictors in downscaling the precipitation. Downscaling was performed on the basis of established relationships between historical Global Summary of Day observed precipitation records from 43 stations and National Center for Environmental Prediction re-analysis large scale atmospheric predictors. Although the selection of predictors was challenging during the set-up of SDSM, they were found to be indicative of important physical forcings in the basins. The precipitation of both basins was largely influenced by geopotential height: the Ganges precipitation was modulated by the U component of the wind and specific humidity at 500 and 1000 h Pa pressure levels; whereas, the Brahmaputra precipitation was modulated by the V component of the wind at 850 and 1000 h Pa pressure levels. The evaluation of the SDSM performance indicated that model accuracy for reproducing precipitation at the monthly scale was acceptable, but at the daily scale the model inadequately simulated some daily extreme precipitation events. Therefore, while the downscaled precipitation may not be the suitable input to analyze future extreme flooding or drought events, it could be adequate for analysis of future freshwater availability. Analysis of the CGCM3.1 downscaled precipitation projection with respect to observed precipitation reveals that the precipitation regime in each basin may be significantly impacted by climate change

Valley dependent transport in graphene L junction

Science.gov (United States)

Chan, K. S.

2018-05-01

We studied the valley dependent transport in graphene L junctions connecting an armchair lead and a zigzag lead. The junction can be used in valleytronic devices and circuits. Electrons injected from the armchair lead into the junction is not valley polarized, but they can become valley polarized in the zigzag lead. There are Fermi energies, where the current in the zigzag lead is highly valley polarized and the junction is an efficient generator of valley polarized current. The features of the valley polarized current depend sensitively on the widths of the two leads, as well as the number of dimers in the armchair lead, because this number has a sensitive effect on the band structure of the armchair lead. When an external potential is applied to the junction, the energy range with high valley polarization is enlarged enhancing its function as a generator of highly valley polarized current. The scaling behavior found in other graphene devices is also found in L junctions, which means that the results presented here can be extended to junctions with larger dimensions after appropriate scaling of the energy.

Method of manufacturing Josephson junction integrated circuits

International Nuclear Information System (INIS)

Jillie, D.W. Jr.; Smith, L.N.

1985-01-01

Josephson junction integrated circuits of the current injection type and magnetically controlled type utilize a superconductive layer that forms both Josephson junction electrode for the Josephson junction devices on the integrated circuit as well as a ground plane for the integrated circuit. Large area Josephson junctions are utilized for effecting contact to lower superconductive layers and islands are formed in superconductive layers to provide isolation between the groudplane function and the Josephson junction electrode function as well as to effect crossovers. A superconductor-barrier-superconductor trilayer patterned by local anodization is also utilized with additional layers formed thereover. Methods of manufacturing the embodiments of the invention are disclosed

delta-biased Josephson tunnel junctions

DEFF Research Database (Denmark)

Monaco, R.; Mygind, Jesper; Koshelet, V.

2010-01-01

Abstract: The behavior of a long Josephson tunnel junction drastically depends on the distribution of the dc bias current. We investigate the case in which the bias current is fed in the central point of a one-dimensional junction. Such junction configuration has been recently used to detect...... the persistent currents circulating in a superconducting loop. Analytical and numerical results indicate that the presence of fractional vortices leads to remarkable differences from the conventional case of uniformly distributed dc bias current. The theoretical findings are supported by detailed measurements...

Junction depth measurement using carrier illumination

International Nuclear Information System (INIS)

Borden, Peter

2001-01-01

Carrier Illumination [trade mark] (CI) is a new method recently developed to meet the need for a non-destructive, high throughput junction depth measurement on patterned wafers. A laser beam creates a quasi-static excess carrier profile in the semiconductor underlying the activated junction. The excess carrier profile is fairly constant below the junction, and drops rapidly in the junction, creating a steep index of refraction gradient at the junction edge. Interference with light reflected from this index gradient provides a signal that is analyzed to determine the junction depth. The paper summarizes evaluation of performance in full NMOS and PMOS process flows, on both bare and patterned wafers. The aims have been to validate (1) performance in the presence of underlying layers typically found at the source/drain (S/D) process steps and (2) measurement on patterned wafers. Correlation of CI measurements to SIMS and transistor drive current are shown. The data were obtained from NMOS structures using As S/D and LDD implants. Correlations to SRP, SIMS and sheet resistance are shown for PMOS structures using B 11 LDD implants. Gage capability measurements are also presented

NbN tunnel junctions

International Nuclear Information System (INIS)

Villegier, J.C.; Vieux-Rochaz, L.; Goniche, M.; Renard, P.; Vabre, M.

1984-09-01

All-niobium nitride Josephon junctions have been prepared successfully using a new processing called SNOP: Selective Niobium (nitride) Overlap Process. Such a process involves the ''trilayer'' deposition on the whole wafer before selective patterning of the electrodes by optically controlled dry reactive ion etching. Only two photomask levels are need to define an ''overlap'' or a ''cross-type'' junction with a good accuracy. The properties of the niobium nitride films deposited by DC-magnetron sputtering and the surface oxide growth are analysed. The most critical point to obtain high quality and high gap value junctions resides in the early stage of the NbN counterelectrode growth. Some possibilities to overcome such a handicap exist even if the fabrication needs substrate temperatures below 250 0 C

Hysteresis development in superconducting Josephson junctions

International Nuclear Information System (INIS)

Refai, T.F.; Shehata, L.N.

1988-09-01

The resistively and capacitive shunted junction model is used to investigate hysteresis development in superconducting Josephson junctions. Two empirical formulas that relate the hysteresis width and the quasi-particle diffusion length in terms of the junctions electrical parameters, temperature and frequency are obtained. The obtained formulas provide a simple tool to investigate the full potentials of the hysteresis phenomena. (author). 9 refs, 3 figs

Fabrication of Josephson Junction without shadow evaporation

Science.gov (United States)

Wu, Xian; Ku, Hsiangsheng; Long, Junling; Pappas, David

We developed a new method of fabricating Josephson Junction (Al/AlOX/Al) without shadow evaporation. Statistics from room temperature junction resistance and measurement of qubits are presented. Unlike the traditional ``Dolan Bridge'' technique, this method requires two individual lithographies and straight evaporations of Al. Argon RF plasma is used to remove native AlOX after the first evaporation, followed by oxidation and second Al evaporation. Junction resistance measured at room temperature shows linear dependence on Pox (oxidation pressure), √{tox} (oxidation time), and inverse proportional to junction area. We have seen 100% yield of qubits made with this method. This method is promising because it eliminates angle dependence during Junction fabrication, facilitates large scale qubits fabrication.

Quantum synchronization effects in intrinsic Josephson junctions

International Nuclear Information System (INIS)

Machida, M.; Kano, T.; Yamada, S.; Okumura, M.; Imamura, T.; Koyama, T.

2008-01-01

We investigate quantum dynamics of the superconducting phase in intrinsic Josephson junctions of layered high-T c superconductors motivated by a recent experimental observation for the switching rate enhancement in the low temperature quantum regime. We pay attention to only the capacitive coupling between neighboring junctions and perform large-scale simulations for the Schroedinger equation derived from the Hamiltonian considering the capacitive coupling alone. The simulation focuses on an issue whether the switching of a junction induces those of the other junctions or not. The results reveal that the superconducting phase dynamics show synchronous behavior with increasing the quantum character, e.g., decreasing the junction plane area and effectively the temperature. This is qualitatively consistent with the experimental result

Entropy Flow Through Near-Critical Quantum Junctions

Science.gov (United States)

Friedan, Daniel

2017-05-01

This is the continuation of Friedan (J Stat Phys, 2017. doi: 10.1007/s10955-017-1752-8). Elementary formulas are derived for the flow of entropy through a circuit junction in a near-critical quantum circuit close to equilibrium, based on the structure of the energy-momentum tensor at the junction. The entropic admittance of a near-critical junction in a bulk-critical circuit is expressed in terms of commutators of the chiral entropy currents. The entropic admittance at low frequency, divided by the frequency, gives the change of the junction entropy with temperature—the entropic "capacitance". As an example, and as a check on the formalism, the entropic admittance is calculated explicitly for junctions in bulk-critical quantum Ising circuits (free fermions, massless in the bulk), in terms of the reflection matrix of the junction. The half-bit of information capacity per end of critical Ising wire is re-derived by integrating the entropic "capacitance" with respect to temperature, from T=0 to T=∞.

Ballistic Josephson junctions based on CVD graphene

Science.gov (United States)

Li, Tianyi; Gallop, John; Hao, Ling; Romans, Edward

2018-04-01

Josephson junctions with graphene as the weak link between superconductors have been intensely studied in recent years, with respect to both fundamental physics and potential applications. However, most of the previous work was based on mechanically exfoliated graphene, which is not compatible with wafer-scale production. To overcome this limitation, we have used graphene grown by chemical vapour deposition (CVD) as the weak link of Josephson junctions. We demonstrate that very short, wide CVD-graphene-based Josephson junctions with Nb electrodes can work without any undesirable hysteresis in their electrical characteristics from 1.5 K down to a base temperature of 320 mK, and their gate-tuneable critical current shows an ideal Fraunhofer-like interference pattern in a perpendicular magnetic field. Furthermore, for our shortest junctions (50 nm in length), we find that the normal state resistance oscillates with the gate voltage, consistent with the junctions being in the ballistic regime, a feature not previously observed in CVD-graphene-based Josephson junctions.

Overlap junctions for high coherence superconducting qubits

Science.gov (United States)

Wu, X.; Long, J. L.; Ku, H. S.; Lake, R. E.; Bal, M.; Pappas, D. P.

2017-07-01

Fabrication of sub-micron Josephson junctions is demonstrated using standard processing techniques for high-coherence, superconducting qubits. These junctions are made in two separate lithography steps with normal-angle evaporation. Most significantly, this work demonstrates that it is possible to achieve high coherence with junctions formed on aluminum surfaces cleaned in situ by Ar plasma before junction oxidation. This method eliminates the angle-dependent shadow masks typically used for small junctions. Therefore, this is conducive to the implementation of typical methods for improving margins and yield using conventional CMOS processing. The current method uses electron-beam lithography and an additive process to define the top and bottom electrodes. Extension of this work to optical lithography and subtractive processes is discussed.

Surface-Enhanced Raman Scattering in Molecular Junctions.

Science.gov (United States)

Iwane, Madoka; Fujii, Shintaro; Kiguchi, Manabu

2017-08-18

Surface-enhanced Raman scattering (SERS) is a surface-sensitive vibrational spectroscopy that allows Raman spectroscopy on a single molecular scale. Here, we present a review of SERS from molecular junctions, in which a single molecule or molecules are made to have contact from the top to the bottom of metal surfaces. The molecular junctions are nice platforms for SERS as well as transport measurement. Electronic characterization based on the transport measurements of molecular junctions has been extensively studied for the development of miniaturized electronic devices. Simultaneous SERS and transport measurement of the molecular junctions allow both structural (geometrical) and electronic information on the single molecule scale. The improvement of SERS measurement on molecular junctions open the door toward new nanoscience and nanotechnology in molecular electronics.

Primary Tunnel Junction Thermometry

International Nuclear Information System (INIS)

Pekola, Jukka P.; Holmqvist, Tommy; Meschke, Matthias

2008-01-01

We describe the concept and experimental demonstration of primary thermometry based on a four-probe measurement of a single tunnel junction embedded within four arrays of junctions. We show that in this configuration random sample specific and environment-related errors can be avoided. This method relates temperature directly to Boltzmann constant, which will form the basis of the definition of temperature and realization of official temperature scales in the future

Ginzburg–Landau theory of mesoscopic multi-band Josephson junctions

Energy Technology Data Exchange (ETDEWEB)

Romeo, F.; De Luca, R., E-mail: rdeluca@unisa.it

2017-05-15

Highlights: • We generalize, in the realm of the Ginzburg–Landau theory, the de Gennes matching-matrix method for the interface order parameters to describe the superconducting properties of multi-band mesoscopic Josephson junctions. • The results are in agreement with a microscopic treatment of nanobridge junctions. • Thermal stability of the nanobridge junction is discussed in connection with recent experiments on iron-based grain-boundary junctions. - Abstract: A Ginzburg–Landau theory for multi-band mesoscopic Josephson junctions has been developed. The theory, obtained by generalizing the de Gennes matching-matrix method for the interface order parameters, allows the study of the phase dynamics of various types of mesoscopic Josephson junctions. As a relevant application, we studied mesoscopic double-band junctions also in the presence of a superconducting nanobridge interstitial layer. The results are in agreement with a microscopic treatment of the same system. Furthermore, thermal stability of the nanobridge junction is discussed in connection with recent experiments on iron-based grain-boundary junctions.

The influence of junction conformation on RNA cleavage by the hairpin ribozyme in its natural junction form.

Science.gov (United States)

Thomson, J B; Lilley, D M

1999-01-01

In the natural form of the hairpin ribozyme the two loop-carrying duplexes that comprise the majority of essential bases for activity form two adjacent helical arms of a four-way RNA junction. In the present work we have manipulated the sequence around the junction in a way known to perturb the global folding properties. We find that replacement of the junction by a different sequence that has the same conformational properties as the natural sequence gives closely similar reaction rate and Arrhenius activation energy for the substrate cleavage reaction. By comparison, rotation of the natural sequence in order to alter the three-dimensional folding of the ribozyme leads to a tenfold reduction in the kinetics of cleavage. Replacement with the U1 four-way junction that is resistant to rotation into the antiparallel structure required to allow interaction between the loops also gives a tenfold reduction in cleavage rate. The results indicate that the conformation of the junction has a major influence on the catalytic activity of the ribozyme. The results are all consistent with a role for the junction in the provision of a framework by which the loops are presented for interaction in order to create the active form of the ribozyme. PMID:10024170

Design of thin InGaAsN(Sb) n-i-p junctions for use in four-junction concentrating photovoltaic devices

Science.gov (United States)

Wilkins, Matthew M.; Gupta, James; Jaouad, Abdelatif; Bouzazi, Boussairi; Fafard, Simon; Boucherif, Abderraouf; Valdivia, Christopher E.; Arès, Richard; Aimez, Vincent; Schriemer, Henry P.; Hinzer, Karin

2017-04-01

Four-junction solar cells for space and terrestrial applications require a junction with a band gap of ˜1 eV for optimal performance. InGaAsN or InGaAsN(Sb) dilute nitride junctions have been demonstrated for this purpose, but in achieving the 14 mA/cm2 short-circuit current needed to match typical GaInP and GaAs junctions, the open-circuit voltage (VOC) and fill factor of these junctions are compromised. In multijunction devices incorporating materials with short diffusion lengths, we study the use of thin junctions to minimize sensitivity to varying material quality and ensure adequate transmission into lower junctions. An n-i-p device with 0.65-μm absorber thickness has sufficient short-circuit current, however, it relies less heavily on field-aided collection than a device with a 1-μm absorber. Our standard cell fabrication process, which includes a rapid thermal anneal of the contacts, yields a significant improvement in diffusion length and device performance. By optimizing a four-junction cell around a smaller 1-sun short-circuit current of 12.5 mA/cm2, we produced an InGaAsN(Sb) junction with open-circuit voltage of 0.44 V at 1000 suns (1 sun=100 mW/cm2), diode ideality factor of 1.4, and sufficient light transmission to allow >12.5 mA/cm2 in all four subcells.

Harmonic synchronization in resistively coupled Josephson junctions

International Nuclear Information System (INIS)

Blackburn, J.A.; Gronbech-Jensen, N.; Smith, H.J.T.

1994-01-01

The oscillations of two resistively coupled Josephson junctions biased only by a single dc current source are shown to lock harmonically in a 1:2 mode over a significant range of bias current, even when the junctions are identical. The dependence of this locking on both junction and coupling parameters is examined, and it is found that, for this particular two-junction configuration, 1:1 locking can never occur, and also that a minimum coupling coefficient is needed to support harmonic locking. Some issues related to subharmonic locking are also discussed

Supramolecular Systems and Chemical Reactions in Single-Molecule Break Junctions.

Science.gov (United States)

Li, Xiaohui; Hu, Duan; Tan, Zhibing; Bai, Jie; Xiao, Zongyuan; Yang, Yang; Shi, Jia; Hong, Wenjing

2017-04-01

The major challenges of molecular electronics are the understanding and manipulation of the electron transport through the single-molecule junction. With the single-molecule break junction techniques, including scanning tunneling microscope break junction technique and mechanically controllable break junction technique, the charge transport through various single-molecule and supramolecular junctions has been studied during the dynamic fabrication and continuous characterization of molecular junctions. This review starts from the charge transport characterization of supramolecular junctions through a variety of noncovalent interactions, such as hydrogen bond, π-π interaction, and electrostatic force. We further review the recent progress in constructing highly conductive molecular junctions via chemical reactions, the response of molecular junctions to external stimuli, as well as the application of break junction techniques in controlling and monitoring chemical reactions in situ. We suggest that beyond the measurement of single molecular conductance, the single-molecule break junction techniques provide a promising access to study molecular assembly and chemical reactions at the single-molecule scale.

Josephson junctions of multiple superconducting wires

Science.gov (United States)

Deb, Oindrila; Sengupta, K.; Sen, Diptiman

2018-05-01

We study the spectrum of Andreev bound states and Josephson currents across a junction of N superconducting wires which may have s - or p -wave pairing symmetries and develop a scattering matrix based formalism which allows us to address transport across such junctions. For N ≥3 , it is well known that Berry curvature terms contribute to the Josephson currents; we chart out situations where such terms can have relatively large effects. For a system of three s -wave or three p -wave superconductors, we provide analytic expressions for the Andreev bound-state energies and study the Josephson currents in response to a constant voltage applied across one of the wires; we find that the integrated transconductance at zero temperature is quantized to integer multiples of 4 e2/h , where e is the electron charge and h =2 π ℏ is Planck's constant. For a sinusoidal current with frequency ω applied across one of the wires in the junction, we find that Shapiro plateaus appear in the time-averaged voltage across that wire for any rational fractional multiple (in contrast to only integer multiples in junctions of two wires) of 2 e /(ℏ ω ) . We also use our formalism to study junctions of two p -wave and one s -wave wires. We find that the corresponding Andreev bound-state energies depend on the spin of the Bogoliubov quasiparticles; this produces a net magnetic moment in such junctions. The time variation of these magnetic moments may be controlled by an external voltage applied across the junction. We discuss experiments which may test our theory.

Molecular Diffusion through Cyanobacterial Septal Junctions.

Science.gov (United States)

Nieves-Morión, Mercedes; Mullineaux, Conrad W; Flores, Enrique

2017-01-03

Heterocyst-forming cyanobacteria grow as filaments in which intercellular molecular exchange takes place. During the differentiation of N 2 -fixing heterocysts, regulators are transferred between cells. In the diazotrophic filament, vegetative cells that fix CO 2 through oxygenic photosynthesis provide the heterocysts with reduced carbon and heterocysts provide the vegetative cells with fixed nitrogen. Intercellular molecular transfer has been traced with fluorescent markers, including calcein, 5-carboxyfluorescein, and the sucrose analogue esculin, which are observed to move down their concentration gradient. In this work, we used fluorescence recovery after photobleaching (FRAP) assays in the model heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 to measure the temperature dependence of intercellular transfer of fluorescent markers. We find that the transfer rate constants are directly proportional to the absolute temperature. This indicates that the "septal junctions" (formerly known as "microplasmodesmata") linking the cells in the filament allow molecular exchange by simple diffusion, without any activated intermediate state. This constitutes a novel mechanism for molecular transfer across the bacterial cytoplasmic membrane, in addition to previously characterized mechanisms for active transport and facilitated diffusion. Cyanobacterial septal junctions are functionally analogous to the gap junctions of metazoans. Although bacteria are frequently considered just as unicellular organisms, there are bacteria that behave as true multicellular organisms. The heterocyst-forming cyanobacteria grow as filaments in which cells communicate. Intercellular molecular exchange is thought to be mediated by septal junctions. Here, we show that intercellular transfer of fluorescent markers in the cyanobacterial filament has the physical properties of simple diffusion. Thus, cyanobacterial septal junctions are functionally analogous to metazoan gap junctions

Josephson tunnel junctions in niobium films

International Nuclear Information System (INIS)

Wiik, Tapio.

1976-12-01

A method of fabricating stable Josephson tunnel junctions with reproducible characteristics is described. The junctions have a sandwich structure consisting of a vacuum evaporated niobium film, a niobium oxide layer produced by the glow discharge method and a lead film deposited by vacuum evaporation. Difficulties in producing thin-film Josephson junctions are discussed. Experimental results suggest that the lower critical field of the niobium film is the most essential parameter when evaluating the quality of these junctions. The dependence of the lower critical field on the film thickness and on the Ginzburg-Landau parameter of the film is studied analytically. Comparison with the properties of the evaporated films and with the previous calculations for bulk specimens shows that the presented model is applicable for most of the prepared samples. (author)

Josephson junctions with ferromagnetic alloy interlayer

Energy Technology Data Exchange (ETDEWEB)

Himmel, Nico

2015-07-23

Josephson junctions are used as active devices in superconducting electronics and quantum information technology. Outstanding properties are their distinct non-linear electrical characteristics and a usually sinusoidal relation between the current and the superconducting phase difference across the junction. In general the insertion of ferromagnetic material in the barrier of a Josephson junction is associated with a suppression of superconducting correlations. But also new phenomena can arise which may allow new circuit layouts and enhance the performance of applications. This thesis presents a systematic investigation for two concepts to fabricate Josephson junctions with a rather uncommon negative critical current. Such devices exhibit an intrinsic phase slip of π between the electrodes, so they are also known as π junctions. Both studies go well beyond existing experiments and in one system a π junction is shown for the first time. All the thin film junctions are based on superconducting Nb electrodes. In a first approach, barriers made from Si and Fe were investigated with respect to the realisation of π junctions by spin-flip processes. The distribution of Fe in the Si matrix was varied from pure layers to disperse compounds. The systematic fabrication of alloy barriers was facilitated by the development of a novel timing-based combinatorial sputtering technique for planetary deposition systems. An orthogonal gradient approach allowed to create binary layer libraries with independent variations of thickness and composition. Second, Nb vertical stroke AlO{sub x} vertical stroke Nb vertical stroke Ni{sub 60}Cu{sub 40} vertical stroke Nb (SIsFS) double barrier junctions were experimentally studied for the occurrence of proximity effect induced order parameter oscillations. Detailed dependencies of the critical current density on the thickness of s-layer and F-layer were acquired and show a remarkable agreement to existing theoretical predictions. Especially

Josephson junctions with ferromagnetic alloy interlayer

International Nuclear Information System (INIS)

Himmel, Nico

2015-01-01

Josephson junctions are used as active devices in superconducting electronics and quantum information technology. Outstanding properties are their distinct non-linear electrical characteristics and a usually sinusoidal relation between the current and the superconducting phase difference across the junction. In general the insertion of ferromagnetic material in the barrier of a Josephson junction is associated with a suppression of superconducting correlations. But also new phenomena can arise which may allow new circuit layouts and enhance the performance of applications. This thesis presents a systematic investigation for two concepts to fabricate Josephson junctions with a rather uncommon negative critical current. Such devices exhibit an intrinsic phase slip of π between the electrodes, so they are also known as π junctions. Both studies go well beyond existing experiments and in one system a π junction is shown for the first time. All the thin film junctions are based on superconducting Nb electrodes. In a first approach, barriers made from Si and Fe were investigated with respect to the realisation of π junctions by spin-flip processes. The distribution of Fe in the Si matrix was varied from pure layers to disperse compounds. The systematic fabrication of alloy barriers was facilitated by the development of a novel timing-based combinatorial sputtering technique for planetary deposition systems. An orthogonal gradient approach allowed to create binary layer libraries with independent variations of thickness and composition. Second, Nb vertical stroke AlO x vertical stroke Nb vertical stroke Ni 60 Cu 40 vertical stroke Nb (SIsFS) double barrier junctions were experimentally studied for the occurrence of proximity effect induced order parameter oscillations. Detailed dependencies of the critical current density on the thickness of s-layer and F-layer were acquired and show a remarkable agreement to existing theoretical predictions. Especially a variation of

Molecular series-tunneling junctions.

Science.gov (United States)

Liao, Kung-Ching; Hsu, Liang-Yan; Bowers, Carleen M; Rabitz, Herschel; Whitesides, George M

2015-05-13

Charge transport through junctions consisting of insulating molecular units is a quantum phenomenon that cannot be described adequately by classical circuit laws. This paper explores tunneling current densities in self-assembled monolayer (SAM)-based junctions with the structure Ag(TS)/O2C-R1-R2-H//Ga2O3/EGaIn, where Ag(TS) is template-stripped silver and EGaIn is the eutectic alloy of gallium and indium; R1 and R2 refer to two classes of insulating molecular units-(CH2)n and (C6H4)m-that are connected in series and have different tunneling decay constants in the Simmons equation. These junctions can be analyzed as a form of series-tunneling junctions based on the observation that permuting the order of R1 and R2 in the junction does not alter the overall rate of charge transport. By using the Ag/O2C interface, this system decouples the highest occupied molecular orbital (HOMO, which is localized on the carboxylate group) from strong interactions with the R1 and R2 units. The differences in rates of tunneling are thus determined by the electronic structure of the groups R1 and R2; these differences are not influenced by the order of R1 and R2 in the SAM. In an electrical potential model that rationalizes this observation, R1 and R2 contribute independently to the height of the barrier. This model explicitly assumes that contributions to rates of tunneling from the Ag(TS)/O2C and H//Ga2O3 interfaces are constant across the series examined. The current density of these series-tunneling junctions can be described by J(V) = J0(V) exp(-β1d1 - β2d2), where J(V) is the current density (A/cm(2)) at applied voltage V and βi and di are the parameters describing the attenuation of the tunneling current through a rectangular tunneling barrier, with width d and a height related to the attenuation factor β.

The effects of crosscutting before gang-ripping on dimension part yields from no. 1 and 2A common red oak lumber

Science.gov (United States)

Charles, J. Gatchell; Janice K. Wiedenbeck; Elizabeth S. Walker; Elizabeth S. Walker

1996-01-01

Mills should have the option to crosscut red oak lumber prior to gang-ripping to remove crook and worthless material and to take advantage of the quality differences between board ends. At least half of No: 1 and 2A Common red oak boards will have end-to-end yield differences of at least 10 percent. Preprocessing will cause a slight decrease in overall yield but will...

Performance of single-junction and dual-junction InGaP/GaAs solar cells under low concentration ratios

International Nuclear Information System (INIS)

Khan, Aurangzeb; Yamaguchi, Masafumi; Takamoto, Tatsuya

2004-01-01

A study of the performance of single-junction InGaP/GaAs and dual-junction InGaP/GaAs tandem cells under low concentration ratios (up to 15 suns), before and after 1 MeV electron irradiation is presented. Analysis of the tunnel junction parameters under different concentrated light illuminations reveals that the peak current (J P ) and valley current (J V ) densities should be greater than the short-circuit current density (J sc ) for better performance. The tunnel junction behavior against light intensity improved after irradiation. This led to the suggestion that the peak current density (J P ) and valley current density (J V ) of the tunnel junction were enhanced after irradiation or the peak current was shifted to higher concentration. The recovery of the radiation damage under concentrated light illumination conditions suggests that the performance of the InGaP/GaAs tandem solar cell can be enhanced even under low concentration ratios

Current noise in tunnel junctions

Energy Technology Data Exchange (ETDEWEB)

Frey, Moritz; Grabert, Hermann [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Strasse 3, 79104, Freiburg (Germany)

2017-06-15

We study current fluctuations in tunnel junctions driven by a voltage source. The voltage is applied to the tunneling element via an impedance providing an electromagnetic environment of the junction. We use circuit theory to relate the fluctuations of the current flowing in the leads of the junction with the voltage fluctuations generated by the environmental impedance and the fluctuations of the tunneling current. The spectrum of current fluctuations is found to consist of three parts: a term arising from the environmental Johnson-Nyquist noise, a term due to the shot noise of the tunneling current and a third term describing the cross-correlation between these two noise sources. Our phenomenological theory reproduces previous results based on the Hamiltonian model for the dynamical Coulomb blockade and provides a simple understanding of the current fluctuation spectrum in terms of circuit theory and properties of the average current. Specific results are given for a tunnel junction driven through a resonator. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

The Importance of National Ethos in Military Victories

Directory of Open Access Journals (Sweden)

Eyal Lewin

2016-08-01

Full Text Available When nations are violently threatened, the choices that they make in order to cope with the challenge of war reflect different alternative possible reactions. They may choose to fiercely fight their battles; they may prefer to surrender, and sometimes the options lay in-between. One puzzle is, therefore, what makes nations fight, and more importantly—what causes them eventually to win or to lose the war. In search for an answer, this study inquires through secondary sources three historical case studies from World War II: Britain, France and Germany, and reviews how each of these major European powers acted throughout the war. After each historical description, the study examines the part that national ethos played in the manner in which each state handled war in moments of crisis. The national ethos of a people is the creed formed from the shared values and traditions through which the nation views its past, present and future; it is the integrating element that defines a nation’s identity and bonds it into a coherent social group. The study reveals how national ethos is intertwined with another phenomenon of social psychology that turns it into a crucial factor in the management of international campaigns: war enthusiasm. Since national ethos is so crucial for the results of the war that a country might lead in order to survive or prosper, it is imperative for decision makers to bear in mind that it is also subject to a process of shaping and reshaping, as the Soviets have proved in relation to their Russian national ethos during World War II. A word of caution, however, is noteworthy: a wide historical perspective shows that even though the right kind of national ethos is essential for winning a war it is far from being enough. Hence national ethos proves, at the end of the day, to be a necessary condition for military victory but certainly not a sufficient one.

Curved Josephson junction

International Nuclear Information System (INIS)

Dobrowolski, Tomasz

2012-01-01

The constant curvature one and quasi-one dimensional Josephson junction is considered. On the base of Maxwell equations, the sine–Gordon equation that describes an influence of curvature on the kink motion was obtained. It is showed that the method of geometrical reduction of the sine–Gordon model from three to lower dimensional manifold leads to an identical form of the sine–Gordon equation. - Highlights: ► The research on dynamics of the phase in a curved Josephson junction is performed. ► The geometrical reduction is applied to the sine–Gordon model. ► The results of geometrical reduction and the fundamental research are compared.

FROM PLEBISCITE TO REFORM: POLITICAL MOVEMENTS AND FUNDAMENTAL CHANGES TO THE PEACE AGREEMENTS IN COLOMBIA AFTER THE VICTORY OF NO IN THE PLEBISCITO OF 2016

OpenAIRE

VICENTE TORRIJOS RIVERA; WALTER ARÉVALO-RAMÍREZ

2017-01-01

This paper describes and analyzes the course of the recent negotiations between the Colombian Government and the FARC guerrilla: its historical background that led to the first version of the agreement, its plebiscite procedure, the victory of the “No” and the proposals for modification, to the New version of the peace agreement. From a case of study method and different theoretical approaches, the document analyzes the contributions of different social movements to solidify a better peace ag...

Josephson tunnel junctions with ferromagnetic interlayer

International Nuclear Information System (INIS)

Weides, M.P.

2006-01-01

Superconductivity and ferromagnetism are well-known physical properties of solid states that have been widely studied and long thought about as antagonistic phenomena due to difference in spin ordering. It turns out that the combination of both superconductor and ferromagnet leads to a very rich and interesting physics. One particular example, the phase oscillations of the superconducting order parameter inside the ferromagnet, will play a major role for the devices discussed in this work. In this thesis, I present Josephson junctions with a thin Al 2 O 3 tunnel barrier and a ferromagnetic interlayer, i.e. superconductor-insulator-ferromagnet-superconductor (SIFS) stacks. The fabrication of junctions was optimized regarding the insulation of electrodes and the homogeneity of the current transport. The junctions were either in the 0 or π coupled ground state, depending on the thickness of the ferromagnetic layer and on temperature. The influence of ferromagnetic layer thickness on the transport properties and the coupling (0, π) of SIFS tunnel junctions was studied. Furthermore, using a stepped ferromagnetic layer with well-chosen thicknesses, I obtained the so-called 0-π Josephson junction. At a certain temperature this 0-π junction can be made perfectly symmetric. In this case the ground state corresponds to a vortex of supercurrent creating a magnetic flux which is a fraction of the magnetic flux quantum Φ 0 . Such structures allow to study the physics of fractional vortices and to build various electronic circuits based on them. The SIFS junctions presented here have an exponentially vanishing damping at T → 0. The SIFS technology developed within the framework of this work may be used to construct classical and quantum devices such as oscillators, memory cells and qubits. (orig.)

Josephson tunnel junctions with ferromagnetic interlayer

Energy Technology Data Exchange (ETDEWEB)

Weides, M.P.

2006-07-01

Superconductivity and ferromagnetism are well-known physical properties of solid states that have been widely studied and long thought about as antagonistic phenomena due to difference in spin ordering. It turns out that the combination of both superconductor and ferromagnet leads to a very rich and interesting physics. One particular example, the phase oscillations of the superconducting order parameter inside the ferromagnet, will play a major role for the devices discussed in this work. In this thesis, I present Josephson junctions with a thin Al{sub 2}O{sub 3} tunnel barrier and a ferromagnetic interlayer, i.e. superconductor-insulator-ferromagnet-superconductor (SIFS) stacks. The fabrication of junctions was optimized regarding the insulation of electrodes and the homogeneity of the current transport. The junctions were either in the 0 or {pi} coupled ground state, depending on the thickness of the ferromagnetic layer and on temperature. The influence of ferromagnetic layer thickness on the transport properties and the coupling (0, {pi}) of SIFS tunnel junctions was studied. Furthermore, using a stepped ferromagnetic layer with well-chosen thicknesses, I obtained the so-called 0-{pi} Josephson junction. At a certain temperature this 0-{pi} junction can be made perfectly symmetric. In this case the ground state corresponds to a vortex of supercurrent creating a magnetic flux which is a fraction of the magnetic flux quantum {phi}{sub 0}. Such structures allow to study the physics of fractional vortices and to build various electronic circuits based on them. The SIFS junctions presented here have an exponentially vanishing damping at T {yields} 0. The SIFS technology developed within the framework of this work may be used to construct classical and quantum devices such as oscillators, memory cells and qubits. (orig.)

Mechanically Stacked Dual-Junction and Triple-Junction III-V/Si-IBC Cells with Efficiencies Exceeding 31.5% and 35.4%: Preprint

Energy Technology Data Exchange (ETDEWEB)

Schnabel, Manuel [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Tamboli, Adele C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Warren, Emily L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Schulte-Huxel, Henning [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Klein, Talysa [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Van Hest, Marinus F [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Geisz, John F [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Stradins, Paul [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Steiner, Myles A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rienaecker, Michael [Institute for Solar Energy Research Hamelin (ISFH); Merkle, Agnes [Institute for Solar Energy Research Hamelin (ISFH); Kajari-Schroeder, S. [Institute for Solar Energy Research Hamelin (ISFH); Niepelt, Raphael [Institute for Solar Energy Research Hamelin (ISFH); Schmidt, Jan [Institute for Solar Energy Research Hamelin (ISFH); Leibniz Universitat Hannover; Brendel, Rolf [Institute for Solar Energy Research Hamelin (ISFH); Leibniz Universitat Hannover; Peibst, Robby [Institute for Solar Energy Research Hamelin (ISFH); Leibniz Universitat Hannover

2017-10-02

Despite steady advancements in the efficiency of crystalline Silicon (c-Si) photovoltaics (PV) within the last decades, the theoretical efficiency limit of 29.4 percent depicts an insurmountable barrier for silicon-based single-junction solar cells. Combining the Si cell with a second absorber material on top in a dual junction tandem or triple junction solar cell is an attractive option to surpass this limit significantly. We demonstrate a mechanically stacked GaInP/Si dual-junction cell with an in-house measured efficiency of 31.5 percent and a GaInP/GaAs/Si triple-junction cell with a certified efficiency of 35.4 percent.

Biological Aspects of the Critically Endangered Fish, Labeo boga in the Ganges River, Northwestern Bangladesh

International Nuclear Information System (INIS)

Hossain, M.Y.; Jahan, S.; Jewel, M.A.S.

2015-01-01

The present study reports the first complete and inclusive description of some biological parameters including length-frequency distribution (LFD), sex ratio (SR), length-weight relationship (LWR), condition factors (allometric, KA; Fultons, KF; relative, KR and relative weight, WR) and form factor (a3.0) of Labeo boga in the Ganges River, northwestern Bangladesh. Sampling was conducted using traditional fishing gears during April 2011 to March 2012. For each specimen, total length (TL) was measured to the nearest 0.01 cm using digital slide calipers and total body weight (BW) was measured using an electronic balance with 0.01 g accuracy. The LWR was calculated using the expression: W= a Lb, where W is the BW and L is the TL. A total of 211 specimens ranging from 9.78-27.50 cm TL and 10.00 to 276.10 g BW were studied. BW of females was significantly higher than that of males (Mann-Whitney U-test, p>0.001). However the overall sex ratio did not differ significantly from the expected value of 1:1 (X"2 = 0.12, p > 3.00) in males, females and combined gender and there were significant differences in the intercepts but not in the slopes between the sexes of L. boga in the Ganges River. KF of females was significantly higher than that for males (p<0.001). In addition, the Wilcoxon signed rank test showed that the WR did not differ from 100 for males and females in this study indicating good condition of habitat for L. boga. The results of this study would be an effective tool for fishery specialists to initiate early management strategies and regulations for the sustainable management of the remaining stocks of this species within the Padma River and surrounding ecosystems. (author)

Electromagnetic waves in single- and multi-Josephson junctions

International Nuclear Information System (INIS)

Matsumoto, Hideki; Koyama, Tomio; Machida, Masahiko

2008-01-01

The terahertz wave emission from the intrinsic Josephson junctions is one of recent topics in high T c superconductors. We investigate, by numerical simulation, properties of the electromagnetic waves excited by a constant bias current in the single- and multi-Josephson junctions. Nonlinear equations of phase-differences are solved numerically by treating the effects of the outside electromagnetic fields as dynamical boundary conditions. It is shown that the emitted power of the electromagnetic wave can become large near certain retrapping points of the I-V characteristics. An instability of the inside phase oscillation is related to large amplitude of the oscillatory waves. In the single- (or homogeneous mutli-) Josephson junctions, electromagnetic oscillations can occur either in a form of standing waves (shorter junctions) or by formation of vortex-antivortex pairs (longer junctions). How these two effects affects the behavior of electromagnetic waves in the intrinsic Josephson junctions is discussed

Tunable Nitride Josephson Junctions.

Energy Technology Data Exchange (ETDEWEB)

Missert, Nancy A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Henry, Michael David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lewis, Rupert M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Howell, Stephen W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wolfley, Steven L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brunke, Lyle Brent [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wolak, Matthaeus [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-12-01

We have developed an ambient temperature, SiO₂/Si wafer - scale process for Josephson junctions based on Nb electrodes and Ta x N barriers with tunable electronic properties. The films are fabricated by magnetron sputtering. The electronic properties of the Ta_xN barriers are controlled by adjusting the nitrogen flow during sputtering. This technology offers a scalable alternative to the more traditional junctions based on AlO_x barriers for low - power, high - performance computing.

Scattering theory of superconductive tunneling in quantum junctions

International Nuclear Information System (INIS)

Shumeiko, V.S.; Bratus', E.N.

1997-01-01

A consistent theory of superconductive tunneling in single-mode junctions within a scattering formulation of Bogolyubov-de Gennes quantum mechanics is presented. The dc Josephson effect and dc quasiparticle transport in the voltage-biased junctions are considered. Elastic quasiparticle scattering by the junction determines the equilibrium Josephson current. The origin of Andreev bound states in tunnel junctions and their role in equilibrium Josephson transport are discussed. In contrast, quasiparticle tunneling in voltage-biased junctions is determined by inelastic scattering. A general expression for inelastic scattering amplitudes is derived and the quasiparticle current is calculated at all voltages with emphasis on a discussion of the properties of sub gap tunnel current and the nature of subharmonic gap structure

Paradigm for Distributive & Procedural Justice in Equitable Apportionment of Transboundary Ganges Waters Under Changing Climate & Landuse

Science.gov (United States)

Tyagi, H.; Gosain, A. K.; Khosa, R.; Anand, J.

2015-12-01

Rivers have no regard for human demarcated boundaries. Besides, ever increasing demand-supply gap & vested riparian interests, fuel transboundary water conflicts. For resolving such disputes, appropriation doctrines advocating equity & fairness have received endorsement in the Helsinki Rules-1966 & UN Convention-1997. Thus, current study proposes the principle of equitable apportionment for sharing Ganges waters as it balances the interests & deservedness of all stakeholders, namely, India & its 11 states, Bangladesh, Nepal, & China. The study endeavors to derive a reasonable share of each co-basin state by operationalizing the vague concepts of fairness & equity through an objective & quantitative framework encompassing proportionality & egalitarianism for distributive & procedural justice. Equal weightage factors reflecting hydrology, geography & water use potential are chosen for fair share computation, wherein each contender ranks these factors to maximize his entitlement. If cumulative claims exceed the water availability, each claimant puts forth next ranked factor & this process continues till the claims match availability. Due to inter-annual variability in few factors, scenarios for Rabi & Kharif seasons are considered apart from cases for maximum, upper quartile, median, lower quartile & minimum. Possibility of spatial homogeneity & heterogeneity in factors is also recognized. Sometimes lack of technical information hinders transboundary dispute resolution via legal mechanisms. Hence, the study also attempts to bridge this gap between law & technology through GIS-based SWAT hydrologic model by estimating the Ganges water yield, & consequent share of each riparian for range of flows incorporating e-flows as well, under present & future climate & landuse scenarios. 82% of India's territory lies within interstate rivers, & therefore this research is very pertinent as it can facilitate the decision makers in effective interstate water conflict resolution.

Short chain molecular junctions: Charge transport versus dipole moment

International Nuclear Information System (INIS)

Ikram, I. Mohamed; Rabinal, M.K.

2015-01-01

Graphical abstract: - Highlights: • The role of dipole moment of organic molecules on molecular junctions has been studied. • Molecular junctions constituted using propargyl molecules of different dipole moments. • The electronic properties of the molecules were calculated using Gaussian software. • Junctions show varying rectification due to their varying dipole moment and orientation. - Abstract: The investigation of the influence of dipole moment of short chain organic molecules having three carbon atoms varying in end group on silicon surface was carried on. Here, we use three different molecules of propargyl series varying in dipole moment and its orientation to constitute molecular junctions. The charge transport mechanism in metal–molecules–semiconductor (MMS) junction obtained from current–voltage (I–V) characteristics shows the rectification behavior for two junctions whereas the other junction shows a weak rectification. The electronic properties of the molecules were calculated using Gaussian software package. The observed rectification behavior of these junctions is examined and found to be accounted to the orientation of dipole moment and electron cloud density distribution inside the molecules

Some chaotic features of intrinsically coupled Josephson junctions

International Nuclear Information System (INIS)

Kolahchi, M.R.; Shukrinov, Yu.M.; Hamdipour, M.; Botha, A.E.; Suzuki, M.

2013-01-01

Highlights: ► Intrinsically coupled Josephson junctions model a high-T c superconductor. ► Intrinsically coupled Josephson junctions can act as a chaotic nonlinear system. ► Chaos could be due to resonance overlap. ► Avoiding parameters that lead to chaos is important for the design of resonators. -- Abstract: We look for chaos in an intrinsically coupled system of Josephson junctions. This study has direct applications for the high-T c resonators which require coherence amongst the junctions

2011 Workplace and Equal Opportunity Survey of Reserve Component Members: Qualitative Analysis on Extremist Groups, Hate Crimes, and Gangs

Science.gov (United States)

2014-06-15

White  “There are young teenagers that are in the gangs. Some of these teens do crimes such as theft or trespassing.” —ANG, male, senior...have been forced to eat my meals by myself because of my race and sexual orientation.” — USMCR, male, junior enlisted, Asian  “In [LOCATION] there...senior enlisted, Two or More Races Some comments highlighted hate crimes based on sexual orientation as well as race/ethnicity.  “We have people

Gap junctions and connexin-interacting proteins

NARCIS (Netherlands)

Giepmans, Ben N G

2004-01-01

Gap junctions form channels between adjacent cells. The core proteins of these channels are the connexins. Regulation of gap junction communication (GJC) can be modulated by connexin-associating proteins, such as regulatory protein phosphatases and protein kinases, of which c-Src is the

Face-body integration of intense emotional expressions of victory and defeat.

Directory of Open Access Journals (Sweden)

Lili Wang

Full Text Available Human facial expressions can be recognized rapidly and effortlessly. However, for intense emotions from real life, positive and negative facial expressions are difficult to discriminate and the judgment of facial expressions is biased towards simultaneously perceived body expressions. This study employed event-related potentials (ERPs to investigate the neural dynamics involved in the integration of emotional signals from facial and body expressions of victory and defeat. Emotional expressions of professional players were used to create pictures of face-body compounds, with either matched or mismatched emotional expressions in faces and bodies. Behavioral results showed that congruent emotional information of face and body facilitated the recognition of facial expressions. ERP data revealed larger P1 amplitudes for incongruent compared to congruent stimuli. Also, a main effect of body valence on the P1 was observed, with enhanced amplitudes for the stimuli with losing compared to winning bodies. The main effect of body expression was also observed in N170 and N2, with winning bodies producing larger N170/N2 amplitudes. In the later stage, a significant interaction of congruence by body valence was found on the P3 component. Winning bodies elicited lager P3 amplitudes than losing bodies did when face and body conveyed congruent emotional signals. Beyond the knowledge based on prototypical facial and body expressions, the results of this study facilitate us to understand the complexity of emotion evaluation and categorization out of laboratory.

Planar Josephson tunnel junctions in a transverse magnetic field

DEFF Research Database (Denmark)

Monacoa, R.; Aarøe, Morten; Mygind, Jesper

2007-01-01

demagnetization effects imposed by the tunnel barrier and electrodes geometry are important. Measurements of the junction critical current versus magnetic field in planar Nb-based high-quality junctions with different geometry, size, and critical current density show that it is advantageous to use a transverse......Traditionally, since the discovery of the Josephson effect in 1962, the magnetic diffraction pattern of planar Josephson tunnel junctions has been recorded with the field applied in the plane of the junction. Here we discuss the static junction properties in a transverse magnetic field where...

A Week Is a Long Time in Politics: The Health Implications of Jeremy Corbyn's UK Labour Party Leadership Victory.

Science.gov (United States)

Scott-Samuel, Alex; Bambra, Clare

2016-01-01

For more than 30 years, socialism within the UK Labour Party - which was in government from 1997 to 2010 and is currently the main UK parliamentary opposition - has been in decline. Despite its origins as a party of and for the working class, Labour has become at best a social democratic party with strong neoliberal leanings. However, in the recent leadership election that followed Labour's general election defeat in May 2015, the socialist Jeremy Corbyn confounded all expectations by winning Labour's leadership with a substantial majority. We describe the political context of Corbyn's controversial victory and discuss its potential short- and medium-term impact on England's troubled National Health Service and on the public health. © The Author(s) 2015.

Particle detection with superconducting tunnel junctions

International Nuclear Information System (INIS)

Jany, P.

1990-08-01

At the Institute of Experimental Nuclear Physics of the University of Karlsruhe (TH) and at the Institute for Nuclear Physics of the Kernforschungszentrum Karlsruhe we started to produce superconducting tunnel junctions and to investigate them for their suitability as particle detectors. The required facilities for the production of tunnel junctions and the experimental equipments to carry out experiments with them were erected. Experiments are presented in which radiations of different kinds of particles could successfully be measured with the tunnel junctions produced. At first we succeeded in detectioning light pulses of a laser. In experiments with alpha-particles of an energy of 4,6 MeV the alpha-particles were detected with an energy resolution of 1,1%, and it was shown in specific experiments that the phonons originating from the deposition of energy by an alpha-particle in the substrate can be detected with superconducting tunnel junctions at the surface. On that occasion it turned out that the signals could be separated with respect to their point of origin (tunnel junction, contact leads, substrate). Finally X-rays with an energy of 6 keV were detected with an energy resolution of 8% in a test arrangement that makes use of the so-called trapping effect to read out a larger absorber volume. (orig.) [de

Effect of solar-cell junction geometry on open-circuit voltage

Science.gov (United States)

Weizer, V. G.; Godlewski, M. P.

1985-01-01

Simple analytical models have been found that adequately describe the voltage behavior of both the stripe junction and dot junction grating cells as a function of junction area. While the voltage in the former case is found to be insensitive to junction area reduction, significant voltage increases are shown to be possible for the dot junction cell. With regard to cells in which the junction area has been increased in a quest for better performance, it was found that (1) texturation does not affect the average saturation current density J0, indicating that the texturation process is equivalent to a simple extension of junction area by a factor of square root of 3 and (2) the vertical junction cell geometry produces a sizable decrease in J0 that, unfortunately, is more than offset by the effects of attendant areal increases.

Advance of Mechanically Controllable Break Junction for Molecular Electronics.

Science.gov (United States)

Wang, Lu; Wang, Ling; Zhang, Lei; Xiang, Dong

2017-06-01

Molecular electronics stands for the ultimate size of functional elements, keeping up with an unstoppable trend over the past few decades. As a vital component of molecular electronics, single molecular junctions have attracted significant attention from research groups all over the world. Due to its pronounced superiority, the mechanically controllable break junctions (MCBJ) technique has been widely applied to characterize the dynamic performance of single molecular junctions. This review presents a system analysis for single-molecule junctions and offers an overview of four test-beds for single-molecule junctions, thus offering more insight into the mechanisms of electron transport. We mainly focus on the development of state-of-the-art mechanically controlled break junctions. The three-terminal gated MCBJ approaches are introduced to manipulate the electron transport of molecules, and MCBJs are combined with characterization techniques. Additionally, applications of MCBJs and remarkable properties of single molecules are addressed. Finally, the challenges and perspective for the mechanically controllable break junctions technique are provided.

Microwave phase locking of Josephson-junction fluxon oscillators

DEFF Research Database (Denmark)

Salerno, M.; Samuelsen, Mogens Rugholm; Filatrella, G.

1990-01-01

Application of the classic McLaughlin-Scott soliton perturbation theory to a Josephson-junction fluxon subjected to a microwave field that interacts with the fluxon only at the junction boundaries reduces the problem of phase locking of the fluxon oscillation to the study of a two-dimensional fun......Application of the classic McLaughlin-Scott soliton perturbation theory to a Josephson-junction fluxon subjected to a microwave field that interacts with the fluxon only at the junction boundaries reduces the problem of phase locking of the fluxon oscillation to the study of a two...

The critical current of point symmetric Josephson tunnel junctions

International Nuclear Information System (INIS)

Monaco, Roberto

2016-01-01

Highlights: • We disclose some geometrical properties of the critical current field dependence that apply to a large class of Josephson junctions characterized by a point symmetric shape. • The developed theory is valid for any orientation of the applied magnetic field, therefore it allows the determine the consequences of field misalignment in the experimental setups. • We also address that the threshold curves of Josephson tunnel junctions with complex shapes can be expressed as a linear combination of the threshold curves of junctions with simpler point symmetric shapes. - Abstract: The physics of Josephson tunnel junctions drastically depends on their geometrical configurations. The shape of the junction determines the specific form of the magnetic-field dependence of its Josephson current. Here we address the magnetic diffraction patterns of specially shaped planar Josephson tunnel junctions in the presence of an in-plane magnetic field of arbitrary orientations. We focus on a wide ensemble of junctions whose shape is invariant under point reflection. We analyze the implications of this type of isometry and derive the threshold curves of junctions whose shape is the union or the relative complement of two point symmetric plane figures.

Solar cell junction temperature measurement of PV module

KAUST Repository

Huang, B.J.

2011-02-01

The present study develops a simple non-destructive method to measure the solar cell junction temperature of PV module. The PV module was put in the environmental chamber with precise temperature control to keep the solar PV module as well as the cell junction in thermal equilibrium with the chamber. The open-circuit voltage of PV module Voc is then measured using a short pulse of solar irradiation provided by a solar simulator. Repeating the measurements at different environment temperature (40-80°C) and solar irradiation S (200-1000W/m2), the correlation between the open-circuit voltage Voc, the junction temperature Tj, and solar irradiation S is derived.The fundamental correlation of the PV module is utilized for on-site monitoring of solar cell junction temperature using the measured Voc and S at a short time instant with open circuit. The junction temperature Tj is then determined using the measured S and Voc through the fundamental correlation. The outdoor test results show that the junction temperature measured using the present method, Tjo, is more accurate. The maximum error using the average surface temperature Tave as the junction temperature is 4.8 °C underestimation; while the maximum error using the present method is 1.3 °C underestimation. © 2010 Elsevier Ltd.

Soliton excitations in Josephson tunnel junctions

DEFF Research Database (Denmark)

Lomdahl, P. S.; Sørensen, O. H.; Christiansen, Peter Leth

1982-01-01

A detailed numerical study of a sine-Gordon model of the Josephson tunnel junction is compared with experimental measurements on junctions with different L / λJ ratios. The soliton picture is found to apply well on both relatively long (L / λJ=6) and intermediate (L / λJ=2) junctions. We find good...... agreement for the current-voltage characteristics, power output, and for the shape and height of the zero-field steps (ZFS). Two distinct modes of soliton oscillations are observed: (i) a bunched or congealed mode giving rise to the fundamental frequency f1 on all ZFS's and (ii) a "symmetric" mode which...... on the Nth ZFS yields the frequency Nf1 Coexistence of two adjacent frequencies is found on the third ZFS of the longer junction (L / λJ=6) in a narrow range of bias current as also found in the experiments. Small asymmetries in the experimental environment, a weak magnetic field, e.g., is introduced via...

Constructing carbon nanotube junctions by Ar ion beam irradiation

International Nuclear Information System (INIS)

Ishaq, Ahmad; Ni Zhichun; Yan Long; Gong Jinlong; Zhu Dezhang

2010-01-01

Carbon nanotubes (CNTs) irradiated by Ar ion beams at elevated temperature were studied. The irradiation-induced defects in CNTs are greatly reduced by elevated temperature. Moreover, the two types of CNT junctions, the crossing junction and the parallel junction, were formed. And the CNT networks may be fabricated by the two types of CNT junctions. The formation process and the corresponding mechanism of CNT networks are discussed.

Field modulation of the critical current in magnetic Josephson junctions

International Nuclear Information System (INIS)

Blamire, M G; Smiet, C B; Banerjee, N; Robinson, J W A

2013-01-01

The dependence of the critical current of a simple Josephson junction on the applied magnetic field is well known and, for a rectangular junction, gives rise to the classic ‘Fraunhofer’ modulation with periodic zeros at the fields that introduce a flux quantum into the junction region. Much recent work has been performed on Josephson junctions that contain magnetic layers. The magnetization of such layers introduces additional flux into the junction and, for large junction areas or strong magnetic materials, can significantly distort the modulation of the critical current and strongly suppress the maximum critical current. The growing interest in junctions that induce odd-frequency triplet pairing in a ferromagnet, and the need to make quantitative comparisons with theory, mean that a full understanding of the role of magnetic barriers in controlling the critical current is necessary. This paper analyses the effect of magnetism and various magnetic configurations on Josephson critical currents; the overall treatment applies to junctions of general shape, but the specific cases of square and rectangular junctions are considered. (paper)

Shunted-Josephson-junction model. II. The nonautonomous case

DEFF Research Database (Denmark)

Belykh, V. N.; Pedersen, Niels Falsig; Sørensen, O. H.

1977-01-01

The shunted-Josephson-junction model with a monochromatic ac current drive is discussed employing the qualitative methods of the theory of nonlinear oscillations. As in the preceding paper dealing with the autonomous junction, the model includes a phase-dependent conductance and a shunt capacitance....... The mathematical discussion makes use of the phase-space representation of the solutions to the differential equation. The behavior of the trajectories in phase space is described for different characteristic regions in parameter space and the associated features of the junction IV curve to be expected are pointed...... out. The main objective is to provide a qualitative understanding of the junction behavior, to clarify which kinds of properties may be derived from the shunted-junction model, and to specify the relative arrangement of the important domains in the parameter-space decomposition....

Observation of supercurrent in graphene-based Josephson junction

Energy Technology Data Exchange (ETDEWEB)

Wang, Libin; Li, Sen; Kang, Ning [Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871 (China); Xu, Chuan; Ren, Wencai [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

2015-07-01

Josephson junctions with a normal metal region sandwiched between two superconductors (S) are known as superconductor- normal-superconductor (SNS) structures. It has attracted significant attention especially when changing the normal metal with graphene, which allow for high tunability with the gate voltage and to study the proximity effect of the massless Dirac fermions. Here we report our work on graphene-based Josephson junction with a new two dimensional superconductor crystal, which grown directly on graphene, as superconducting electrodes. At low temperature, we observer proximity effect induced supercurrent flowing through the junction. The temperature and the magnetic field dependences of the critical current characteristics of the junction are also studied. The critical current exhibits a Fraunhofer-type diffraction pattern against magnetic field. Our experiments provided a new route of fabrication of graphene-based Josephson junction.

Josephson junction arrays and superconducting wire networks

International Nuclear Information System (INIS)

Lobb, C.J.

1992-01-01

Techniques used to fabricate integrated circuits make it possible to construct superconducting networks containing as many as 10 6 wires or Josephson junctions. Such networks undergo phase transitions from resistive high-temperature states to ordered low-resistance low-temperature states. The nature of the phase transition depends strongly on controllable parameters such as the strength of the superconductivity in each wire or junction and the external magnetic field. This paper will review the physics of these phase transitions, starting with the simplest zero-magnetic field case. This leads to a Kosterlitz-Thouless transition when the junctions or wires are weak, and a simple mean-field fransition when the junctions or wires are strong. Rich behavior, resulting from frustration, occurs in the presence of a magnetic field. (orig.)

Phenomenological approach to bistable behavior of Josephson junctions

International Nuclear Information System (INIS)

Nishi, K.; Nara, S.; Hamanaka, K.

1985-01-01

The interaction of unbiased Josephson junction with external electromagnetic field in the presence of externally applied uniform magnetic field is theoretically examined by means of phenomenological treatment. It is proposed that an irradiated junction with suitably chosen parameters shows a bistable behavior of voltage across the junction as a function of the radiation intensity

Multiplication in Silicon p-n Junctions

DEFF Research Database (Denmark)

Moll, John L.

1965-01-01

Multiplication values were measured in the collector junctions of silicon p-n-p and n-p-n transistors before and after bombardment by 1016 neutrons/cm2. Within experimental error there was no change either in junction fields, as deduced from capacitance measurements, or in multiplication values i...

Anchored PKA as a gatekeeper for gap junctions.

Science.gov (United States)

Pidoux, Guillaume; Taskén, Kjetil

2015-01-01

Anchored protein kinase A (PKA) bound to A Kinase Anchoring Protein (AKAP) mediates effects of localized increases in cAMP in defined subcellular microdomains and retains the specificity in cAMP-PKA signaling to distinct extracellular stimuli. Gap junctions are pores between adjacent cells constituted by connexin proteins that provide means of communication and transfer of small molecules. While the PKA signaling is known to promote human trophoblast cell fusion, the gap junction communication through connexin 43 (Cx43) is a prerequisite for this process. We recently demonstrated that trophoblast fusion is regulated by ezrin, a known AKAP, which binds to Cx43 and delivers PKA in the vicinity gap junctions. We found that disruption of the ezrin-Cx43 interaction abolished PKA-dependent phosphorylation of Cx43 as well as gap junction communication and subsequently cell fusion. We propose that the PKA-ezrin-Cx43 macromolecular complex regulating gap junction communication constitutes a general mechanism to control opening of Cx43 gap junctions by phosphorylation in response to cAMP signaling in various cell types.

Heat Transport in Graphene Ferromagnet-Insulator-Superconductor Junctions

Institute of Scientific and Technical Information of China (English)

LI Xiao-Wei

2011-01-01

We study heat transport in a graphene ferromagnet-insulator-superconducting junction. It is found that the thermal conductance of the graphene ferromagnet-insulator-superconductor (FIS) junction is an oscillatory function of the barrier strength x in the thin-barrier limit. The gate potential U0 decreases the amplitude of thermal conductance oscillation. Both the amplitude and phase of the thermal conductance oscillation varies with the exchange energy Eh. The thermal conductance of a graphene FIS junction displays the usual exponential dependence on temperature, reflecting the s-wave symmetry of superconducting graphene.%@@ We study heat transport in a graphene ferromagnet-insulator-superconducting junction.It is found that the thermal conductance of the graphene ferromagnet-insulator-superconductor(FIS)junction is an oscillatory function of the barrier strength X in the thin-barrier limit.The gate potential Uo decreases the amplitude of thermal conductance oscillation.Both the amplitude and phase of the thermal conductance oscillation varies with the exchange energy Eh.The thermal conductance of a graphene FIS junction displays the usual exponential dependence on temperature, reflecting the s-wave symmetry of superconducting graphene.

Terahertz Responses of Intrinsic Josephson Junctions in High TC Superconductors

International Nuclear Information System (INIS)

Wang, H. B.; Wu, P. H.; Yamashita, T.

2001-01-01

High frequency responses of intrinsic Josephson junctions up to 2.5THz, including the observation of Shapiro steps under various conditions, are reported and discussed in this Letter. The sample was an array of intrinsic Josephson junctions singled out from inside a high T C superconducting Bi 2 Sr 2 CaCu 2 O 8+x single crystal, with a bow-tie antenna integrated to it. The number of junctions in the array was controllable, the junctions were homogeneous, the distribution of applied irradiation among the junctions was even, and the junctions could synchronously respond to high frequency irradiation

Long Josephson Junction Stack Coupled to a Cavity

DEFF Research Database (Denmark)

Madsen, Søren Peder; Pedersen, Niels Falsig; Groenbech-Jensen, N.

2007-01-01

A stack of inductively coupled long Josephson junctions are modeled as a system of coupled sine-Gordon equations. One boundary of the stack is coupled electrically to a resonant cavity. With one fluxon in each Josephson junction, the inter-junction fluxon forces are repulsive. We look at a possible...... transition, induced by the cavity, to a bunched state....

Structural Origins of Conductance Fluctuations in Gold–Thiolate Molecular Transport Junctions

KAUST Repository

French, William R.

2013-03-21

We report detailed atomistic simulations combined with high-fidelity conductance calculations to probe the structural origins of conductance fluctuations in thermally evolving Au-benzene-1,4-dithiolate-Au junctions. We compare the behavior of structurally ideal junctions (where the electrodes are modeled as flat surfaces) to structurally realistic, experimentally representative junctions resulting from break-junction simulations. The enhanced mobility of metal atoms in structurally realistic junctions results in significant changes to the magnitude and origin of the conductance fluctuations. Fluctuations are larger by a factor of 2-3 in realistic junctions compared to ideal junctions. Moreover, in junctions with highly deformed electrodes, the conductance fluctuations arise primarily from changes in the Au geometry, in contrast to results for junctions with nondeformed electrodes, where the conductance fluctuations are dominated by changes in the molecule geometry. These results provide important guidance to experimentalists developing strategies to control molecular conductance, and also to theoreticians invoking simplified structural models of junctions to predict their behavior. © 2013 American Chemical Society.

Structural Origins of Conductance Fluctuations in Gold–Thiolate Molecular Transport Junctions

KAUST Repository

French, William R.; Iacovella, Christopher R.; Rungger, Ivan; Souza, Amaury Melo; Sanvito, Stefano; Cummings, Peter T.

2013-01-01

We report detailed atomistic simulations combined with high-fidelity conductance calculations to probe the structural origins of conductance fluctuations in thermally evolving Au-benzene-1,4-dithiolate-Au junctions. We compare the behavior of structurally ideal junctions (where the electrodes are modeled as flat surfaces) to structurally realistic, experimentally representative junctions resulting from break-junction simulations. The enhanced mobility of metal atoms in structurally realistic junctions results in significant changes to the magnitude and origin of the conductance fluctuations. Fluctuations are larger by a factor of 2-3 in realistic junctions compared to ideal junctions. Moreover, in junctions with highly deformed electrodes, the conductance fluctuations arise primarily from changes in the Au geometry, in contrast to results for junctions with nondeformed electrodes, where the conductance fluctuations are dominated by changes in the molecule geometry. These results provide important guidance to experimentalists developing strategies to control molecular conductance, and also to theoreticians invoking simplified structural models of junctions to predict their behavior. © 2013 American Chemical Society.

Silicon fiber with p-n junction

International Nuclear Information System (INIS)

Homa, D.; Cito, A.; Pickrell, G.; Hill, C.; Scott, B.

2014-01-01

In this study, we fabricated a p-n junction in a fiber with a phosphorous doped silicon core and fused silica cladding. The fibers were fabricated via a hybrid process of the core-suction and melt-draw techniques and maintained overall diameters ranging from 200 to 900 μm and core diameters of 20–800 μm. The p-n junction was formed by doping the fiber with boron and confirmed via the current-voltage characteristic. The demonstration of a p-n junction in a melt-drawn silicon core fiber paves the way for the seamless integration of optical and electronic devices in fibers.

Quasiparticle current in superconductor-semiconductor-superconductor junctions

International Nuclear Information System (INIS)

Tartakovskij, A.V.; Fistul', M.V.

1988-01-01

It is shown that the quasiparticle current in a superconductor-semiconductor-superconductor junction may significantly increase as a result of resonant passage of the quasiparticle along particular trajectories from periodically situated localized centers. A prediction of the theory is that with increasing junction resistance there should be a change from an excessive current to a insufficient current on the current-voltage characteristics (at high voltages). The effect of transparency of the boundaries on resonance tunneling in such junctions is also investigated

Transport properties of molecular junctions

CERN Document Server

Zimbovskaya, Natalya A

2013-01-01

A comprehensive overview of the physical mechanisms that control electron transport and the characteristics of metal-molecule-metal (MMM) junctions is presented. As far as possible, methods and formalisms presented elsewhere to analyze electron transport through molecules are avoided. This title introduces basic concepts—a description of the electron transport through molecular junctions—and briefly describes relevant experimental methods. Theoretical methods commonly used to analyze the electron transport through molecules are presented. Various effects that manifest in the electron transport through MMMs, as well as the basics of density-functional theory and its applications to electronic structure calculations in molecules are presented. Nanoelectronic applications of molecular junctions and similar systems are discussed as well. Molecular electronics is a diverse and rapidly growing field. Transport Properties of Molecular Junctions presents an up-to-date survey of the field suitable for researchers ...

Spatial inhomogeneous barrier heights at graphene/semiconductor Schottky junctions

Science.gov (United States)

Tomer, Dushyant

Graphene, a semimetal with linear energy dispersion, forms Schottky junction when interfaced with a semiconductor. This dissertation presents temperature dependent current-voltage and scanning tunneling microscopy/spectroscopy (STM/S) measurements performed on graphene Schottky junctions formed with both three and two dimensional semiconductors. To fabricate Schottky junctions, we transfer chemical vapor deposited monolayer graphene onto Si- and C-face SiC, Si, GaAs and MoS2 semiconducting substrates using polymer assisted chemical method. We observe three main type of intrinsic spatial inhomogeneities, graphene ripples, ridges and semiconductor steps in STM imaging that can exist at graphene/semiconductor junctions. Tunneling spectroscopy measurements reveal fluctuations in graphene Dirac point position, which is directly related to the Schottky barrier height. We find a direct correlation of Dirac point variation with the topographic undulations of graphene ripples at the graphene/SiC junction. However, no such correlation is established at graphene/Si and Graphene/GaAs junctions and Dirac point variations are attributed to surface states and trapped charges at the interface. In addition to graphene ripples and ridges, we also observe atomic scale moire patterns at graphene/MoS2 junction due to van der Waals interaction at the interface. Periodic topographic modulations due to moire pattern do not lead to local variation in graphene Dirac point, indicating that moire pattern does not contribute to fluctuations in electronic properties of the heterojunction. We perform temperature dependent current-voltage measurements to investigate the impact of topographic inhomogeneities on electrical properties of the Schottky junctions. We observe temperature dependence in junction parameters, such as Schottky barrier height and ideality factor, for all types of Schottky junctions in forward bias measurements. Standard thermionic emission theory which assumes a perfect

Systematic study of shallow junction formation on germanium substrates

DEFF Research Database (Denmark)

Hellings, Geert; Rosseel, Erik; Clarysse, Trudo

2011-01-01

Published results on Ge junctions are benchmarked systematically using RS–XJ plots. The electrical activation level required to meet the ITRS targets is calculated. Additionally, new results are presented on shallow furnace-annealed B junctions and shallow laser-annealed As junctions. Co-implanting...

Junction Potentials Bias Measurements of Ion Exchange Membrane Permselectivity.

Science.gov (United States)

Kingsbury, Ryan S; Flotron, Sophie; Zhu, Shan; Call, Douglas F; Coronell, Orlando

2018-04-17

Ion exchange membranes (IEMs) are versatile materials relevant to a variety of water and waste treatment, energy production, and industrial separation processes. The defining characteristic of IEMs is their ability to selectively allow positive or negative ions to permeate, which is referred to as permselectivity. Measured values of permselectivity that equal unity (corresponding to a perfectly selective membrane) or exceed unity (theoretically impossible) have been reported for cation exchange membranes (CEMs). Such nonphysical results call into question our ability to correctly measure this crucial membrane property. Because weighing errors, temperature, and measurement uncertainty have been shown to not explain these anomalous permselectivity results, we hypothesized that a possible explanation are junction potentials that occur at the tips of reference electrodes. In this work, we tested this hypothesis by comparing permselectivity values obtained from bare Ag/AgCl wire electrodes (which have no junction) to values obtained from single-junction reference electrodes containing two different electrolytes. We show that permselectivity values obtained using reference electrodes with junctions were greater than unity for CEMs. In contrast, electrodes without junctions always produced permselectivities lower than unity. Electrodes with junctions also resulted in artificially low permselectivity values for AEMs compared to electrodes without junctions. Thus, we conclude that junctions in reference electrodes introduce two biases into results in the IEM literature: (i) permselectivity values larger than unity for CEMs and (ii) lower permselectivity values for AEMs compared to those for CEMs. These biases can be avoided by using electrodes without a junction.

On simulation of local fluxes in molecular junctions

Science.gov (United States)

Cabra, Gabriel; Jensen, Anders; Galperin, Michael

2018-05-01

We present a pedagogical review of the current density simulation in molecular junction models indicating its advantages and deficiencies in analysis of local junction transport characteristics. In particular, we argue that current density is a universal tool which provides more information than traditionally simulated bond currents, especially when discussing inelastic processes. However, current density simulations are sensitive to the choice of basis and electronic structure method. We note that while discussing the local current conservation in junctions, one has to account for the source term caused by the open character of the system and intra-molecular interactions. Our considerations are illustrated with numerical simulations of a benzenedithiol molecular junction.

Shunted-Josephson-junction model. I. The autonomous case

DEFF Research Database (Denmark)

Belykh, V. N.; Pedersen, Niels Falsig; Sørensen, O. H.

1977-01-01

The shunted-Josephson-junction model: the parallel combination of a capacitance, a phase-dependent conductance, and an ideal junction element biased by a constant current, is discussed for arbitrary values of the junction parameters. The main objective is to provide a qualitative understanding...... current-voltage curves are presented. The case with a time-dependent monochromatic bias current is treated in a similar fashion in the companion paper....

Joint diseases: from connexins to gap junctions.

Science.gov (United States)

Donahue, Henry J; Qu, Roy W; Genetos, Damian C

2017-12-19

Connexons form the basis of hemichannels and gap junctions. They are composed of six tetraspan proteins called connexins. Connexons can function as individual hemichannels, releasing cytosolic factors (such as ATP) into the pericellular environment. Alternatively, two hemichannel connexons from neighbouring cells can come together to form gap junctions, membrane-spanning channels that facilitate cell-cell communication by enabling signalling molecules of approximately 1 kDa to pass from one cell to an adjacent cell. Connexins are expressed in joint tissues including bone, cartilage, skeletal muscle and the synovium. Indicative of their importance as gap junction components, connexins are also known as gap junction proteins, but individual connexin proteins are gaining recognition for their channel-independent roles, which include scaffolding and signalling functions. Considerable evidence indicates that connexons contribute to the function of bone and muscle, but less is known about the function of connexons in other joint tissues. However, the implication that connexins and gap junctional channels might be involved in joint disease, including age-related bone loss, osteoarthritis and rheumatoid arthritis, emphasizes the need for further research into these areas and highlights the therapeutic potential of connexins.

Electrochemically assisted mechanically controllable break junction studies on the stacking configurations of oligo(phenylene ethynylene)s molecular junctions

International Nuclear Information System (INIS)

Zheng, Jue-Ting; Yan, Run-Wen; Tian, Jing-Hua; Liu, Jun-Yang; Pei, Lin-Qi; Wu, De-Yin; Dai, Ke; Yang, Yang; Jin, Shan

2016-01-01

Highlights: • I-V characteristics of a series of oligo(phenylene ethynylene)s molecular junctions were measured. • Conductance values were found to be dependent on molecular length and substituent group. • The measured low conductance values were explained by theoretical calculations. • EC-MCBJ is feasible to fabricate and characterize molecular junctions. - Abstract: We demonstrate an electrochemically assisted mechanically controllable break junction (EC-MCBJ) approach for current-voltage characteristic (I-V curve) measurements of metal/molecule/metal junctions. A series of oligo(phenylene ethynylene)s compounds (OPEs), including those involving electron withdrawing substituent group and different backbone lengths, had been successfully designed, synthesized, and placed onto the fabricated nanogap to form molecular junctions. The observed evolution in the measured conductances of OPEs indicates that there is a dependence of conductance on molecular length and substituent group. Compared with those extracted from conductance histogram construction, the conductances of OPEs measured from I-V curves are considerably lower. Based on the transmission spectra of OPEs that calculated by density functional theory (DFT) combined with non-equilibrium Green’s function (NEGF) method, this difference was attributed to our distinct experimental operation, which may give rise to a stacking configuration of two OPE molecules.

ALTERNATIVE MATERIALS FOR RAMP-EDGE SNS JUNCTIONS

International Nuclear Information System (INIS)

Jia, Q.; Fan, Y.; Gim, Y.

1999-01-01

We report on the processing optimization and fabrication of ramp-edge high-temperature superconducting junctions by using alternative materials for both superconductor electrodes and normal-metal barrier. By using Ag-doped YBa 2 Cu 3 O 7-x (Ag:YBCO) as electrodes and a cation-modified compound of (Pr y Gd 0.6-y )Ca 0.4 Ba 1.6 La 0.4 Cu 3 O 7 (y = 0.4, 0.5, and 0.6) as a normal-metal barrier, high-temperature superconducting Josephson junctions have been fabricated in a ramp-edge superconductor/normal-metal/superconductor (SNS) configuration. By using Ag:YBCO as electrodes, we have found that the processing controllability /reproducibility and the stability of the SNS junctions are improved substantially. The junctions fabricated with these alternative materials show well-defined RSJ-like current vs voltage characteristics at liquid nitrogen temperature

Electron-beam damaged high-temperature superconductor Josephson junctions

International Nuclear Information System (INIS)

Pauza, A.J.; Booij, W.E.; Herrmann, K.; Moore, D.F.; Blamire, M.G.; Rudman, D.A.; Vale, L.R.

1997-01-01

Results are presented on the fabrication and characterization of high critical temperature Josephson junctions in thin films of YBa 2 Cu 3 O 7-δ produced by the process of focused electron-beam irradiation using 350 keV electrons. The junctions so produced have uniform spatial current densities, can be described in terms of the resistive shunted junction model, and their current densities can be tailored for a given operating temperature. The physical properties of the damaged barrier can be described as a superconducting material of either reduced or zero critical temperature (T c ), which has a length of ∼15nm. The T c reduction is caused primarily by oxygen Frenkel defects in the Cu - O planes. The large beam currents used in the fabrication of the junctions mean that the extent of the barrier is limited by the incident electron-beam diameter, rather than by scattering within the film. The properties of the barrier can be calculated using a superconductor/normal/superconductor (SNS) junction model with no boundary resistance. From the SNS model, we can predict the scaling of the critical current resistance (I c R n ) product and gain insight into the factors controlling the junction properties, T c , and reproducibility. From the measured I c R n scaling data, we can predict the I c R n product of a junction at a given operating temperature with a given current density. I c R n products of ∼2mV can be achieved at 4.2 K. The reproducibility of several junctions in a number of samples can be characterized by the ratio of the maximum-to-minimum critical currents on the same substrate of less than 1.4. Stability over several months has been demonstrated at room and refrigerator temperatures (297 and 281 K) for junctions that have been initially over damaged and then annealed at temperatures ∼380K. (Abstract Truncated)

Shot noise in YBCO bicrystal Josephson junctions

DEFF Research Database (Denmark)

Constantinian, K.Y.; Ovsyannikov, G.A.; Borisenko, I.V.

2003-01-01

We measured spectral noise density in YBCO symmetric bicrystal Josephson junctions on sapphire substrates at bias voltages up to 100 mV and T 4.2 K. Normal state resistance of the Josephson junctions, R-N = 20-90 Omega and ICRN up to 2.2 mV have been observed in the experimental samples. Noise...... may explain the experimentally measured linewidth broadening of Josephson oscillations at mm and submm wave frequencies in high-Tc superconducting junctions. Experimental results are discussed in terms of bound states existing at surfaces of d-wave superconducting electrodes....

Intraepithelial lymphocytes express junctional molecules in murine small intestine

International Nuclear Information System (INIS)

Inagaki-Ohara, Kyoko; Sawaguchi, Akira; Suganuma, Tatsuo; Matsuzaki, Goro; Nawa, Yukifumi

2005-01-01

Intestinal intraepithelial lymphocytes (IEL) that reside at basolateral site regulate the proliferation and differentiation of epithelial cells (EC) for providing a first line of host defense in intestine. However, it remains unknown how IEL interact and communicate with EC. Here, we show that IEL express junctional molecules like EC. We identified mRNA expression of the junctional molecules in IEL such as zonula occludens (ZO)-1, occludin and junctional adhesion molecule (JAM) (tight junction), β-catenin and E-cadherin (adherens junction), and connexin26 (gap junction). IEL constitutively expressed occludin and E-cadherin at protein level, while other T cells in the thymus, spleen, liver, mesenteric lymph node, and Peyer's patches did not. γδ IEL showed higher level of these expressions than αβ IEL. The expression of occludin was augmented by anti-CD3 Ab stimulation. These results suggest the possibility of a novel role of IEL concerning epithelial barrier and communication between IEL and EC

Affordance-based individuation of junctions in Open Street Map

Directory of Open Access Journals (Sweden)

Simon Scheider

2012-06-01

Full Text Available We propose an algorithm that can be used to identify automatically the subset of street segments of a road network map that corresponds to a junction. The main idea is to use turn-compliant locomotion affordances, i.e., restricted patterns of supported movement, in order to specify junctions independently of their data representation, and in order to motivate tractable individuation and classification strategies. We argue that common approaches based solely on geometry or topology of the street segment graph are useful but insufficient proxies. They miss certain turn restrictions essential to junctions. From a computational viewpoint, the main challenge of affordance-based individuation of junctions lies in its complex recursive definition. In this paper, we show how Open Street Map data can be interpreted into locomotion affordances, and how the recursive junction definition can be translated into a deterministic algorithm. We evaluate this algorithm by applying it to small map excerpts in order to delineate the contained junctions.

STIM proteins and the endoplasmic reticulum-plasma membrane junctions.

Science.gov (United States)

Carrasco, Silvia; Meyer, Tobias

2011-01-01

Eukaryotic organelles can interact with each other through stable junctions where the two membranes are kept in close apposition. The junction that connects the endoplasmic reticulum to the plasma membrane (ER-PM junction) is unique in providing a direct communication link between the ER and the PM. In a recently discovered signaling process, STIM (stromal-interacting molecule) proteins sense a drop in ER Ca(2+) levels and directly activate Orai PM Ca(2+) channels across the junction space. In an inverse process, a voltage-gated PM Ca(2+) channel can directly open ER ryanodine-receptor Ca(2+) channels in striated-muscle cells. Although ER-PM junctions were first described 50 years ago, their broad importance in Ca(2+) signaling, as well as in the regulation of cholesterol and phosphatidylinositol lipid transfer, has only recently been realized. Here, we discuss research from different fields to provide a broad perspective on the structures and unique roles of ER-PM junctions in controlling signaling and metabolic processes.

Predictability of current and future multi-river discharges: Ganges, Brahmaputra, Yangtze, Blue Nile, and Murray-Darling rivers

Science.gov (United States)

Jian, Jun

2007-12-01

Determining river discharge is of critical importance to many societies as they struggle with fresh water supply and risk of flooding. In Bangladesh, floods occur almost every year but with sufficient irregularity to have adverse social and economical consequences. Important goals are to predict the discharge to be used for the optimization of agricultural practices, disaster mitigation and water resource management. The aim of this study is to determine the predictability of river discharge in a number of major rivers on time scale varying from weeks to a century. We investigated predictability considering relationship between SST and discharge. Next, we consider IPCC model projections of river discharge while the models are statistically adjusted against observed discharges. In this study, we consider five rivers, the Ganges, the Brahmaputra, the Yangtze, the Blue Nile, and the Murray-Darling Rivers. On seasonal time scales, statistically significant correlations are found between mean monthly equatorial Pacific sea surface temperature (SST) and the summer Ganges discharge with lead times of 2-3 months due to oscillations of the El Nino-Southern Oscillation (ENSO) phenomena. In addition, there are strong correlations in the southwest and northeast Pacific. These, too, appear to be tied to the ENSO cycle. The Brahmaputra discharge, on the other hand, shows somewhat weaker relationships with tropical SST. Strong lagged correlations relationships are found with SST in the Bay of Bengal but these are the result of very warm SSTs and exceptional Brahmaputra discharge during the summer of 1998. When this year is removed from the time series, relationships weaken everywhere except in the northwestern Pacific for the June discharge and in areas of the central Pacific straddling the equator for the July discharge. The relationships are relative strong, but they are persistent from month to month and suggest that two different and sequential factors influence Brahmaputra

FROM PLEBISCITE TO REFORM: POLITICAL MOVEMENTS AND FUNDAMENTAL CHANGES TO THE PEACE AGREEMENTS IN COLOMBIA AFTER THE VICTORY OF NO IN THE PLEBISCITO OF 2016

Directory of Open Access Journals (Sweden)

VICENTE TORRIJOS RIVERA

2017-09-01

Full Text Available This paper describes and analyzes the course of the recent negotiations between the Colombian Government and the FARC guerrilla: its historical background that led to the first version of the agreement, its plebiscite procedure, the victory of the “No” and the proposals for modification, to the New version of the peace agreement. From a case of study method and different theoretical approaches, the document analyzes the contributions of different social movements to solidify a better peace agreement and the persistent challenges in its implementation.

Morphological variation of the kidney secondary to junctional parenchyma on ultrasound

International Nuclear Information System (INIS)

Lee, Ji Yoon; Park, Byeong Ho; Nam, Kyeong Jin; Choi, Jong Cheol; Koo, Bong Sig; Kim, Jou Yeoun; Ahn, Seung Eon; Lee, Yung Il

1996-01-01

To evaluate the prevalance of morphological variation of the kidney secondary to junctional parenchyma, as well as to analyze the ultrasonographic features of junctional parenchyma. Two hundred and eighty two kidneys of 141 patient without clinical or radiologic evidence of renal disease were prospectively analysed using ultrasound. In all patients, ultrasonograms were obtained in sagittal, coronal and transaxial planes. The kidney was considered to have morphological variation if the ultrasonogram demonstrated junctional parenchymal defect of line ; those showing such variation were classified as one of three types : continuous, discontinuous, or junctional parenchymal line or defect without junctional parenchyma. The prevalance and ultrasonographic features of the kidneys were evaluated. Morphological variation was noted in 71 cases(25%). the continuous type accounted for 54% of these, the discontinuous type for 38%, and junctional parenchymal defect or line without junctional parenchyma for 8%. In all cases, junctional parenchyma was located approximately at the junction of the upper and middle third of the kidney, and had the same echogenecity as the renal cortex. An understanding of the morphological variation of the kidney resulting from junctional renal parenchyma would be helpful in differentiating pseudotumor from true renal neoplasm

Visualizing supercurrents in 0-{pi} ferromagnetic Josephson tunnel junctions

Energy Technology Data Exchange (ETDEWEB)

Goldobin, Edward; Guerlich, Christian; Gaber, Tobias; Koelle, Dieter; Kleiner, Reinhold [Physikalisches Institut and Center for Collective Quantum Phenomena, Universitaet Tuebingen (Germany); Weides, Martin; Kohlstedt, Hermann [Institute of Solid State Physics, Reserch Center Juelich (Germany)

2009-07-01

So-called 0 and {pi} Josephson junctions can be treated as having positive and negative critical currents. This implies that the same phase shift applied to a Josephson junction causes counterflow of supercurrents in 0 and in {pi} junctions connected in parallel provided they are short in comparison with Josephson penetration depth {lambda}{sub J}. We have fabricated several 0, {pi}, 0-{pi}, 0-{pi}-0 and 20 x (0-{pi}-) planar superconductor-insulator-ferromagnet-superconductor Josephson junctions and studied the spatial supercurrent density distribution j{sub s}(x,y) across the junction area using low temperature scanning electron microscopy. At zero magnetic field we clearly see counterflow of the supercurrents in 0 and {pi} regions. The picture also changes consistently in the applied magnetic field.

Fabrication of magnetic tunnel junctions with epitaxial and textured ferromagnetic layers

Science.gov (United States)

Chang, Y. Austin; Yang, Jianhua Joshua

2008-11-11

This invention relates to magnetic tunnel junctions and methods for making the magnetic tunnel junctions. The magnetic tunnel junctions include a tunnel barrier oxide layer sandwiched between two ferromagnetic layers both of which are epitaxial or textured with respect to the underlying substrate upon which the magnetic tunnel junctions are grown. The magnetic tunnel junctions provide improved magnetic properties, sharper interfaces and few defects.

Spin, Vibrations and Radiation in Superconducting Junctions

NARCIS (Netherlands)

Padurariu, C.

2013-01-01

This thesis presents the theoretical study of superconducting transport in several devices based on superconducting junctions. The important feature of these devices is that the transport properties of the junction are modified by the interaction with another physical system integrated in the

The atmospheric branch of the hydrological cycle over the Indus, Ganges, and Brahmaputra river basins

Science.gov (United States)

Sorí, Rogert; Nieto, Raquel; Drumond, Anita; Vicente-Serrano, Sergio M.; Gimeno, Luis

2017-12-01

The atmospheric branch of the hydrological cycle over the Indus, Ganges, and Brahmaputra river basins (IRB, GRB, and BRB respectively) in the South Asian region was investigated. The 3-dimensional model FLEXPART v9.0 was utilized. An important advantage of this model is that it permits the computation of the freshwater budget on air parcel trajectories both backward and forward in time from 0.1 to 1000 hPa in the atmospheric vertical column. The analysis was conducted for the westerly precipitation regime (WPR) (November-April) and the monsoonal precipitation regime (MPR) (May-October) in the period from 1981 to 2015. The main terrestrial and oceanic climatological moisture sources for the IRB, GRB, and BRB and their contribution to precipitation over the basins were identified. For the three basins, the most important moisture sources for precipitation are (i) in the continental regions, the land masses to the west of the basins (in this case called western Asia), the Indian region (IR), and the basin itself, and (ii) from the ocean, the utmost sources being the Indian Ocean (IO) and the Bay of Bengal (BB), and it is remarkable that despite the amount of moisture reaching the Indus and Ganges basins from land sources, the moisture supply from the IO seems to be first associated with the rapid increase or decrease in precipitation over the sources in the MPR. The technique of the composites was used to analyse how the moisture uptake values spatially vary from the sources (the budget of evaporation minus precipitation (E - P) was computed in a backward experiment from the basins) but during the pre-onset and pre-demise dates of the monsoonal rainfall over each basin; this confirmed that over the last days of the monsoon at the basins, the moisture uptake areas decrease in the IO. The Indian region, the Indian Ocean, the Bay of Bengal, and the basins themselves are the main sources of moisture responsible for negative (positive) anomalies of moisture contribution to

Regulation of Tight Junctions in Upper Airway Epithelium

Directory of Open Access Journals (Sweden)

Takashi Kojima

2013-01-01

Full Text Available The mucosal barrier of the upper respiratory tract including the nasal cavity, which is the first site of exposure to inhaled antigens, plays an important role in host defense in terms of innate immunity and is regulated in large part by tight junctions of epithelial cells. Tight junction molecules are expressed in both M cells and dendritic cells as well as epithelial cells of upper airway. Various antigens are sampled, transported, and released to lymphocytes through the cells in nasal mucosa while they maintain the integrity of the barrier. Expression of tight junction molecules and the barrier function in normal human nasal epithelial cells (HNECs are affected by various stimuli including growth factor, TLR ligand, and cytokine. In addition, epithelial-derived thymic stromal lymphopoietin (TSLP, which is a master switch for allergic inflammatory diseases including allergic rhinitis, enhances the barrier function together with an increase of tight junction molecules in HNECs. Furthermore, respiratory syncytial virus infection in HNECs in vitro induces expression of tight junction molecules and the barrier function together with proinflammatory cytokine release. This paper summarizes the recent progress in our understanding of the regulation of tight junctions in the upper airway epithelium under normal, allergic, and RSV-infected conditions.

Victory Gin Lane. Starvation and Beverages in Orwell’s Nineteen Eighty-Four

Directory of Open Access Journals (Sweden)

Paolo Caponi

2015-05-01

Full Text Available Gin is an ubiquitous presence in the domestic and urban scenery of Nineteen Eighty-Four (1949. For a population mercilessly hungered, it represents a handy and cheap commodity item providing a fluid opportunity for social aggregation. Victory Gin, served “in handless chine mugs” (53, is part of the workers’ staple diet at the Ministry of Truth, and is sold “at ten cents the large nip” from the small bar (actually, “a mere hole in the wall”, 51 in the canteen; served with cloves, it is the “speciality” (79 of that disreputable place which is the Chestnut Tree Café, where Winston Smith once spotted three fallen-out-of-favor members of the Inner Party – Jones, Aaronson and Rutherford – drink it silently after their release from Oceania prison camps (79. As is typical of the fate of spirits in literature, gin also serves as self-medication and can fuel a kind of inner escapism. It is to make the world “look more cheerful” that Winston gulps it down “like a dose of medicine”, and only after the “shock” of swallowing it can he squeeze himself into his alcove and begin his diary (7; gin clears out Winston’s stomach (53, and is the ultima ratio against that prescient “dull ache” in his belly (105; 106 that originates after bumping into “the girl with dark hair” (later: Julia one evening outside Mr. Charrington’s shop.

Spin-dependent quasiparticle tunneling in junction superconductor-isolator-ferromagnetic

International Nuclear Information System (INIS)

Shlapak, Yu.V.; Shaternik, V.E.; Rudenko, E.M.

2001-01-01

The influence of Andreev reflection of quasiparticles in transparent tunnel junctions of superconductor-isolator-ferromagnetic on electric-current transport is studied within the framework of the Blonder-Tinkham-Klapwijk (BTK) model. It's obtained that current and signal-to-noise ratio can be increased for the memory cell by using in it the double-barrier tunnel junction ferromagnetic-isolator-superconductor-isolator-ferromagnetic instead off the usual tunnel junction ferromagnetic-isolator-ferromagnetic. The evolution of non-linear (tunnel-type) current-voltage characteristics with increasing of the junction transparency is described. (orig.)

Ileocolic junction resection in dogs and cats: 18 cases.

Science.gov (United States)

Fernandez, Yordan; Seth, Mayank; Murgia, Daniela; Puig, Jordi

2017-12-01

There is limited veterinary literature about dogs or cats with ileocolic junction resection and its long-term follow-up. To evaluate the long-term outcome in a cohort of dogs and cats that underwent resection of the ileocolic junction without extensive (≥50%) small or large bowel resection. Medical records of dogs and cats that had the ileocolic junction resected were reviewed. Follow-up information was obtained either by telephone interview or e-mail correspondence with the referring veterinary surgeons. Nine dogs and nine cats were included. The most common cause of ileocolic junction resection was intussusception in dogs (5/9) and neoplasia in cats (6/9). Two dogs with ileocolic junction lymphoma died postoperatively. Only 2 of 15 animals, for which long-term follow-up information was available, had soft stools. However, three dogs with suspected chronic enteropathy required long-term treatment with hypoallergenic diets alone or in combination with medical treatment to avoid the development of diarrhoea. Four of 6 cats with ileocolic junction neoplasia were euthanised as a consequence of progressive disease. Dogs and cats undergoing ileocolic junction resection and surviving the perioperative period may have a good long-term outcome with mild or absent clinical signs but long-term medical management may be required.

Antireflection coating design for series interconnected multi-junction solar cells

International Nuclear Information System (INIS)

Aiken, Daniel J.

1999-01-01

AR coating design for multi-junction solar cells can be more challenging than in the single junction case. Reasons for this are discussed. Analytical expressions used to optimize AR coatings for single junction solar cells are extended for use in monolithic, series interconnected multi-junction solar cell AR coating design. The result is an analytical expression which relates the solar cell performance (through J(sub SC)) directly to the AR coating design through the device reflectance. It is also illustrated how AR coating design can be used to provide an additional degree of freedom for current matching multi-junction devices

Holographic s-wave and p-wave Josephson junction with backreaction

Energy Technology Data Exchange (ETDEWEB)

Wang, Yong-Qiang; Liu, Shuai [Institute of Theoretical Physics, Lanzhou University,Lanzhou 730000, People’s Republic of (China)

2016-11-22

In this paper, we study the holographic models of s-wave and p-wave Josephoson junction away from probe limit in (3+1)-dimensional spacetime, respectively. With the backreaction of the matter, we obtained the anisotropic black hole solution with the condensation of matter fields. We observe that the critical temperature of Josephoson junction decreases with increasing backreaction. In addition to this, the tunneling current and condenstion of Josephoson junction become smaller as backreaction grows larger, but the relationship between current and phase difference still holds for sine function. Moreover, condenstion of Josephoson junction deceases with increasing width of junction exponentially.

Functional anatomy of the human ureterovesical junction

NARCIS (Netherlands)

Roshani, H.; Dabhoiwala, N. F.; Verbeek, F. J.; Lamers, W. H.

1996-01-01

BACKGROUND: The valve function of the ureterovesical-junction (UVJ) is responsible for protection of the low pressure upper urinary tract from the refluxing of urine from the bladder. Controversy about the microanatomy of the human ureterovesical-junction persists. METHODS: Ten (3 male and 7 female)

Double-well potential in annular Josephson junction

International Nuclear Information System (INIS)

Shaju, P.D.; Kuriakose, V.C.

2004-01-01

A double-well potential suitable for quantum-coherent vortex tunnelling can be created in an annular Josephson junction by inserting a microshort in the junction and by applying an in-plane dc magnetic field. Analysis shows that the intensity of the magnetic field determines the depth of the potential well and the strength of the microshort controls the potential barrier height while a dc bias across the junction tilts the potential well. At milli-Kelvin temperatures, the system is expected to behave as a quantum two-level system and may be useful in designing vortex qubits

Parametric frequency conversion in long Josephson junctions

International Nuclear Information System (INIS)

Irie, F.; Ashihara, S.; Yoshida, K.

1976-01-01

Current steps at voltages corresponding to the parametric coupling between an applied r.f. field and junction resonant modes have been observed in long Josephson tunnel junctions in the flux-flow state. The observed periodic variations of the step height due to the applied magnetic field are explained quantitatively by a perturbational analysis using Josephson phase equations. The present study demonstrates that the moving vortex array can serve as a coherent pump wave for signal waves propagating in the barrier region, which indicates, as a result, the possibility of traveling-wave parametric devices with long Josephson tunnel junctions. (author)

Fractional Solitons in Excitonic Josephson Junctions

Science.gov (United States)

Su, Jung-Jung; Hsu, Ya-Fen

The Josephson effect is especially appealing because it reveals macroscopically the quantum order and phase. Here we study this effect in an excitonic Josephson junction: a conjunct of two exciton condensates with a relative phase ϕ0 applied. Such a junction is proposed to take place in the quantum Hall bilayer (QHB) that makes it subtler than in superconductor because of the counterflow of excitonic supercurrent and the interlayer tunneling in QHB. We treat the system theoretically by first mapping it into a pseudospin ferromagnet then describing it by the Landau-Lifshitz-Gilbert equation. In the presence of interlayer tunneling, the excitonic Josephson junction can possess a family of fractional sine-Gordon solitons that resemble the static fractional Josephson vortices in the extended superconducting Josephson junctions. Interestingly, each fractional soliton carries a topological charge Q which is not necessarily a half/full integer but can vary continuously. The resultant current-phase relation (CPR) shows that solitons with Q =ϕ0 / 2 π are the lowest energy states for small ϕ0. When ϕ0 > π , solitons with Q =ϕ0 / 2 π - 1 take place - the polarity of CPR is then switched.

Inequalities in Human Well-Being in the Urban Ganges Brahmaputra Meghna Delta

Directory of Open Access Journals (Sweden)

Sylvia Szabo

2016-06-01

Full Text Available The recently endorsed Sustainable Development Goals (SDGs agenda unanimously agrees on the need to focus on inclusive development, the importance of eradicating extreme poverty and managing often complex human well-being impacts of rapid urban growth. Sustainable and inclusive urbanisation will accelerate progress towards the SDGs and contribute to eradicating extreme poverty. In tropical delta regions, such as the Ganges Brahmaputra Meghna delta region, urban growth and resulting intra-urban inequalities are accelerated by the impact of environmental and climate change. In this context, the present study uses the 2010 Household Income and Expenditure Survey to analyse the extent of wealth-based inequalities in human well-being in the urban delta region and the determinants of selected welfare measures. The results suggest that the extent of intra-urban inequalities is greatest in educational attainment and access to postnatal healthcare and relatively low in the occurrence of gastric disease. The paper concludes by providing policy recommendations to reduce increasing wealth inequalities in urban areas, thus contributing to sustainable development of the region.

Gravitation at the Josephson Junction

Directory of Open Access Journals (Sweden)

Victor Atanasov

2018-01-01

Full Text Available A geometric potential from the kinetic term of a constrained to a curved hyperplane of space-time quantum superconducting condensate is derived. An energy conservation relation involving the geometric field at every material point in the superconductor is demonstrated. At a Josephson junction the energy conservation relation implies the possibility of transforming electric energy into geometric field energy, that is, curvature of space-time. Experimental procedures to verify that the Josephson junction can act as a voltage-to-curvature converter are discussed.

The cranial-spinal junction in medulloblastoma: does it matter?

International Nuclear Information System (INIS)

Narayana, Ashwatha; Jeswani, Sam; Paulino, Arnold C.

1999-01-01

Purpose: Late effects of treatment in children and young adults with medulloblastoma can be influenced by the technique employed in radiating the craniospinal axis. The purpose of this study is to determine whether the placement of the cranial-spinal junction has an impact on dose to the cervical spinal cord and surrounding organs. Methods and Materials: Five patients underwent computed tomography (CT) simulation in the prone position for craniospinal irradiation. A dose of 36 Gy was prescribed to the entire neuraxis. The doses to the cervical spinal cord and surrounding organs were calculated using a cranial-spinal junction at the C1-C2 vertebral interspace (high junction) or at the lowest point in the neck, with exclusion of the shoulders in the lateral cranial fields (low junction).The volume of critical organs at risk, as well as dose to these structures using the cranial and spinal field(s) were outlined and calculated using the CMS FOCUS 3-dimensional treatment planning system. Results: The average dose to the cervical spinal cord was 11.9% higher than the prescribed dose with the low junction, and 6.7% higher with the high junction. However, doses to the thyroid gland, mandible, pharynx, and larynx were increased by an average of 29.6%, 75.8%, 70.6%, and 227.7%, respectively, by the use of the high junction compared to the low junction. Conclusion: A higher dose to the cervical spinal cord can be minimized by using a high junction. However, this would be at the cost of substantially increased doses to surrounding organs such as the thyroid gland, mandible, pharynx, and larynx. This can be critical in children and young adults, where hypothyroidism, mandibular hypoplasia, and development of second malignancies may be a late sequela of radiation therapy

Chirality effect in disordered graphene ribbon junctions

International Nuclear Information System (INIS)

Long Wen

2012-01-01

We investigate the influence of edge chirality on the electronic transport in clean or disordered graphene ribbon junctions. By using the tight-binding model and the Landauer-Büttiker formalism, the junction conductance is obtained. In the clean sample, the zero-magnetic-field junction conductance is strongly chirality-dependent in both unipolar and bipolar ribbons, whereas the high-magnetic-field conductance is either chirality-independent in the unipolar or chirality-dependent in the bipolar ribbon. Furthermore, we study the disordered sample in the presence of magnetic field and find that the junction conductance is always chirality-insensitive for both unipolar and bipolar ribbons with adequate disorders. In addition, the disorder-induced conductance plateaus can exist in all chiral bipolar ribbons provided the disorder strength is moderate. These results suggest that we can neglect the effect of edge chirality in fabricating electronic devices based on the magnetotransport in a disordered graphene ribbon. (paper)

Junction depth dependence of breakdown in silicon detector diodes

International Nuclear Information System (INIS)

Beck, G.A.; Carter, A.A.; Carter, J.R.; Greenwood, N.M.; Lucas, A.D.; Munday, D.J.; Pritchard, T.W.; Robinson, D.; Wilburn, C.D.; Wyllie, K.

1996-01-01

The high voltage capability of detector diodes fabricated in the planar process is limited by the high field generated at the edge of the junction.We have fabricated diodes with increased junction depth with respect to our standard process and find a significantly higher breakdown voltage,in reasonable agreement with previous studies of junction breakdown. (orig.)

The fallopian tube-peritoneal junction: a potential site of carcinogenesis.

Science.gov (United States)

Seidman, Jeffrey D; Yemelyanova, Anna; Zaino, Richard J; Kurman, Robert J

2011-01-01

Junctions between different types of epithelia are hot spots for carcinogenesis, but the junction of the peritoneal mesothelium with the fallopian tubal epithelium, the tubal-peritoneal junction, has not been characterized earlier. A total of 613 junctional foci in 228 fallopian tube specimens from 182 patients who underwent surgery for a variety of indications, including 27 risk-reducing salpingo-oophorectomy specimens, were studied. Edema, congestion, and dilated lymphatic channels were commonly present. Transitional metaplasia was found at the junction in 20% of patients and mesothelial hyperplasia in 17%. Inflammation at the junction was seen predominantly in patients with salpingitis, torsion, or tubal pregnancy. Ovarian-type stroma was found at the junction in 5% of patients, and was found elsewhere in the tubal lamina propria in an additional 27% of patients. Findings in risk-reducing salpingo-oophorectomy specimens in women with BRCA mutations, a personal history of breast cancer, and/or a family history of breast/ovarian cancer were similar to those in controls. Transitional metaplasia specifically localizes to this junction, and is the probable source of Walthard cell nests. The recently highlighted significance of fimbrial tubal epithelium in the origin of serous ovarian carcinomas and a study suggesting that mucinous and Brenner tumors may arise from transitional-type epithelium in this location suggest that the tubal-peritoneal junction may play a role in the development of these tumors. This is the first comprehensive description of a hitherto unrecognized transitional zone in the adnexa.

Regulation of Endothelial Adherens Junctions by Tyrosine Phosphorylation

Science.gov (United States)

Adam, Alejandro Pablo

2015-01-01

Endothelial cells form a semipermeable, regulated barrier that limits the passage of fluid, small molecules, and leukocytes between the bloodstream and the surrounding tissues. The adherens junction, a major mechanism of intercellular adhesion, is comprised of transmembrane cadherins forming homotypic interactions between adjacent cells and associated cytoplasmic catenins linking the cadherins to the cytoskeleton. Inflammatory conditions promote the disassembly of the adherens junction and a loss of intercellular adhesion, creating openings or gaps in the endothelium through which small molecules diffuse and leukocytes transmigrate. Tyrosine kinase signaling has emerged as a central regulator of the inflammatory response, partly through direct phosphorylation and dephosphorylation of the adherens junction components. This review discusses the findings that support and those that argue against a direct effect of cadherin and catenin phosphorylation in the disassembly of the adherens junction. Recent findings indicate a complex interaction between kinases, phosphatases, and the adherens junction components that allow a fine regulation of the endothelial permeability to small molecules, leukocyte migration, and barrier resealing. PMID:26556953

Two-dimensional non-volatile programmable p-n junctions

Science.gov (United States)

Li, Dong; Chen, Mingyuan; Sun, Zhengzong; Yu, Peng; Liu, Zheng; Ajayan, Pulickel M.; Zhang, Zengxing

2017-09-01

Semiconductor p-n junctions are the elementary building blocks of most electronic and optoelectronic devices. The need for their miniaturization has fuelled the rapid growth of interest in two-dimensional (2D) materials. However, the performance of a p-n junction considerably degrades as its thickness approaches a few nanometres and traditional technologies, such as doping and implantation, become invalid at the nanoscale. Here we report stable non-volatile programmable p-n junctions fabricated from the vertically stacked all-2D semiconductor/insulator/metal layers (WSe2/hexagonal boron nitride/graphene) in a semifloating gate field-effect transistor configuration. The junction exhibits a good rectifying behaviour with a rectification ratio of 104 and photovoltaic properties with a power conversion efficiency up to 4.1% under a 6.8 nW light. Based on the non-volatile programmable properties controlled by gate voltages, the 2D p-n junctions have been exploited for various electronic and optoelectronic applications, such as memories, photovoltaics, logic rectifiers and logic optoelectronic circuits.

Thermionic refrigeration at CNT-CNT junctions

Science.gov (United States)

Li, C.; Pipe, K. P.

2016-10-01

Monte Carlo (MC) simulation is used to study carrier energy relaxation following thermionic emission at the junction of two van der Waals bonded single-walled carbon nanotubes (SWCNTs). An energy-dependent transmission probability gives rise to energy filtering at the junction, which is predicted to increase the average electron transport energy by as much as 0.115 eV, leading to an effective Seebeck coefficient of 386 μV/K. MC results predict a long energy relaxation length (˜8 μm) for hot electrons crossing the junction into the barrier SWCNT. For SWCNTs of optimal length, an analytical transport model is used to show that thermionic cooling can outweigh parasitic heat conduction due to high SWCNT thermal conductivity, leading to a significant cooling capacity (2.4 × 106 W/cm2).

Response of high Tc superconducting Josephson junction to nuclear radiation

International Nuclear Information System (INIS)

Ding Honglin; Zhang Wanchang; Zhang Xiufeng

1992-10-01

The development of nuclear radiation detectors and research on high T c superconducting nuclear radiation detectors are introduced. The emphases are the principle of using thin-film and thick-film Josephson junctions (bridge junction) based on high T c YBCO superconductors to detect nuclear radiation, the fabrication of thin film and thick-film Josephson junction, and response of junction to low energy gamma-rays of 59.5 keV emitted from 241 Am and beta-rays of 546 keV. The results show that a detector for measuring nuclear radiation spectrum made of high T c superconducting thin-film or thick-film, especially, thick-film Josephson junction, certainly can be developed

‘Gap Junctions and Cancer: Communicating for 50 Years’

Science.gov (United States)

Aasen, Trond; Mesnil, Marc; Naus, Christian C.; Lampe, Paul D.; Laird, Dale W.

2017-01-01

Fifty years ago, tumour cells were found to lack electrical coupling, leading to the hypothesis that loss of direct intercellular communication is commonly associated with cancer onset and progression. Subsequent studies linked this phenomenon to gap junctions composed of connexin proteins. While many studies support the notion that connexins are tumour suppressors, recent evidence suggests that, in some tumour types, they may facilitate specific stages of tumour progression through both junctional and non-junctional signalling pathways. This Timeline article highlights the milestones connecting gap junctions to cancer, and underscores important unanswered questions, controversies and therapeutic opportunities in the field. PMID:27782134

The Victory of Anti-Hitler States in the Second World War. The Lend-lease Factor

Directory of Open Access Journals (Sweden)

N P Parkhitko

2015-12-01

Full Text Available The article is focused on the economic aspect of military cooperation between the USSR and the western Allies (first of all, with the USA and Great Britain during the period of the WW II. The statistic data of the military equipment, sent to the USSR by the Allies through Lend-Lease is compared to the statistics of the Soviet domestic military production during the Great Patriotic War. Also the material and human losses of the USSR and the Allies are compared. As the result of the comparison the crucial military, political and economical input of the USSR in the Victory of Anti-Hitler states in the Second World War is advocated. The goal is also to eliminate the pseudo-historic attempts of denigrating the role of the Soviet Union in the Second World War and even its struggle in the period of the Great Patriotic War. Such attempts are being intensified in the last decades especially in the western countries and their message, in the opinion of the author, is to downplay the role of our country on the international arena as it tends to be in the political conjuncture of the early XXI century.

Dynamics of fractional vortices in long Josephson junctions

International Nuclear Information System (INIS)

Gaber, Tobias

2007-01-01

In this thesis static and dynamic properties of fractional vortices in long Josephson junctions are investigated. Fractional vortices are circulating supercurrents similar to the well-known Josephson fluxons. Yet, they show the distinguishing property of carrying only a fraction of the magnetic flux quantum. Fractional vortices are interesting non-linear objects. They spontaneously appear and are pinned at the phase discontinuity points of so called 0-κ junctions but can be bend or flipped by external forces like bias currents or magnetic fields. 0-κ junctions and fractional vortices are generalizations of the well-known 0-π junctions and semifluxons, where not only phase jumps of pi but arbitrary values denoted by kappa are considered. By using so-called artificial 0-κ junctions that are based on standard Nb-AlO x -Nb technology the classical dynamics of fractional vortices has been investigated experimentally for the very first time. Here, half-integer zero field steps could be observed. These voltage steps on the junction's current-voltage characteristics correspond to the periodic flipping/hopping of fractional vortices. In addition, the oscillatory eigenmodes of fractional vortices were investigated. In contrast to fluxons fractional vortices have an oscillatory eigenmode with a frequency within the plasma gap. Using resonance spectroscopy the dependence of the eigenmode frequency on the flux carried by the vortex and an applied bias current was determined. (orig.)

Functional Molecular Junctions Derived from Double Self-Assembled Monolayers.

Science.gov (United States)

Seo, Sohyeon; Hwang, Eunhee; Cho, Yunhee; Lee, Junghyun; Lee, Hyoyoung

2017-09-25

Information processing using molecular junctions is becoming more important as devices are miniaturized to the nanoscale. Herein, we report functional molecular junctions derived from double self-assembled monolayers (SAMs) intercalated between soft graphene electrodes. Newly assembled molecular junctions are fabricated by placing a molecular SAM/(top) electrode on another molecular SAM/(bottom) electrode by using a contact-assembly technique. Double SAMs can provide tunneling conjugation across the van der Waals gap between the terminals of each monolayer and exhibit new electrical functions. Robust contact-assembled molecular junctions can act as platforms for the development of equivalent contact molecular junctions between top and bottom electrodes, which can be applied independently to different kinds of molecules to enhance either the structural complexity or the assembly properties of molecules. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gap junctions-guards of excitability

DEFF Research Database (Denmark)

Stroemlund, Line Waring; Jensen, Christa Funch; Qvortrup, Klaus

2015-01-01

Cardiomyocytes are connected by mechanical and electrical junctions located at the intercalated discs (IDs). Although these structures have long been known, it is becoming increasingly clear that their components interact. This review describes the involvement of the ID in electrical disturbances...... of the heart and focuses on the role of the gap junctional protein connexin 43 (Cx43). Current evidence shows that Cx43 plays a crucial role in organizing microtubules at the intercalated disc and thereby regulating the trafficking of the cardiac sodium channel NaV1.5 to the membrane....

Association of visceral adiposity with oesophageal and junctional adenocarcinomas.

LENUS (Irish Health Repository)

Beddy, P

2012-02-01

BACKGROUND: Obesity is associated with an increased incidence of oesophageal and oesophagogastric junction adenocarcinoma, in particular Siewert types I and II. This study compared abdominal fat composition in patients with oesophageal\\/junctional adenocarcinoma with that in patients with oesophageal squamous cell carcinoma and gastric adenocarcinoma, and in controls. METHOD: In total, 194 patients (110 with oesophageal\\/junctional adenocarcinoma, 38 with gastric adenocarcinoma and 46 with oesophageal squamous cell carcinoma) and 90 matched control subjects were recruited. The abdominal fat area was assessed using computed tomography (CT), and the total fat area (TFA), visceral fat area (VFA) and subcutaneous fat area (SFA) were calculated. RESULTS: Patients with oesophageal\\/junctional adenocarcinoma had significantly higher TFA and VFA values compared with controls (both P < 0.001), patients with gastric adenocarcinoma (P = 0.013 and P = 0.006 respectively) and patients with oesophageal squamous cell carcinoma (both P < 0.001). For junctional tumours, the highest TFA and VFA values were seen in patients with Siewert type I tumours (respectively P = 0.041 and P = 0.033 versus type III; P = 0.332 and P = 0.152 versus type II). CONCLUSION: Patients with oesophageal\\/junctional adenocarcinoma, in particular oesophageal and Siewert type I junctional tumours, have greater CT-defined visceral adiposity than patients with gastric adenocarcinoma or oesophageal squamous cell carcinoma, or controls.

Magnetic interaction between spatially extended superconducting tunnel junctions

DEFF Research Database (Denmark)

Grønbech-Jensen, Niels; Samuelsen, Mogens Rugholm

2002-01-01

A general description of magnetic interactions between superconducting tunnel junctions is given. The description covers a wide range of possible experimental systems, and we explicitly explore two experimentally relevant limits of coupled junctions. One is the limit of junctions with tunneling...... been considered through arrays of superconducting weak links based on semiconductor quantum wells with superconducting electrodes. We use the model to make direct interpretations of the published experiments and thereby propose that long-range magnetic interactions are responsible for the reported...

Cavity syncronisation of underdamped Josephson junction arrays

DEFF Research Database (Denmark)

Barbara, P.; Filatrella, G.; Lobb, C.

2003-01-01

the junctions in the array and an electromagnetic cavity. Here we show that a model of a one-dimensional array of Josephson junctions coupled to a resonator can produce many features of the coherent be havior above threshold, including coherent radiation of power and the shape of the array current...

impairs gap junction function causing congenital cataract

Indian Academy of Sciences (India)

Navya

2017-03-24

Mar 24, 2017 ... experiment showed a lower dye diffusion distance of Cx46 V44M cells, ... Studies of connexins show that channel gating and permeability .... have found that connexin assembled into gap junction plaques is not soluble in 1% ..... high glucose reduces gap junction activity in microvascular endothelial cells.

Spatially resolved detection of mutually locked Josephson junctions in arrays

International Nuclear Information System (INIS)

Keck, M.; Doderer, T.; Huebener, R.P.; Traeuble, T.; Dolata, R.; Weimann, T.; Niemeyer, J.

1997-01-01

Mutual locking due to the internal coupling in two-dimensional arrays of Josephson junctions was investigated. The appearance of Shapiro steps in the current versus voltage curve of a coupled on-chip detector junction is used to indicate coherent oscillations in the array. A highly coherent state is observed for some range of the array bias current. By scanning the array with a low-power electron beam, mutually locked junctions remain locked while the unlocked junctions generate a beam-induced additional voltage drop at the array. This imaging technique allows the detection of the nonlocked or weakly locked Josephson junctions in a (partially) locked array state. copyright 1997 American Institute of Physics

Two coupled Josephson junctions: dc voltage controlled by biharmonic current

International Nuclear Information System (INIS)

Machura, L; Spiechowicz, J; Kostur, M; Łuczka, J

2012-01-01

We study transport properties of two Josephson junctions coupled by an external shunt resistance. One of the junctions (say, the first) is driven by an unbiased ac current consisting of two harmonics. The device can rectify the ac current yielding a dc voltage across the first junction. For some values of coupling strength, controlled by an external shunt resistance, a dc voltage across the second junction can be generated. By variation of system parameters such as the relative phase or frequency of two harmonics, one can conveniently manipulate both voltages with high efficiency, e.g. changing the dc voltages across the first and second junctions from positive to negative values and vice versa. (paper)

Probing electrical transport in individual carbon nanotubes and junctions

International Nuclear Information System (INIS)

Kim, Tae-Hwan; Wendelken, John F; Li Anping; Du Gaohui; Li Wenzhi

2008-01-01

The electrical transport properties of individual carbon nanotubes (CNTs) and multi-terminal junctions of CNTs are investigated with a quadraprobe scanning tunneling microscope. The CNTs used in this study are made of stacked herringbone-type conical graphite sheets with a cone angle of ∼20 deg. to the tube axis, and the CNT junctions have no catalytic particles in the junction areas. The CNTs have a significantly higher resistivity than conventional CNTs with concentric walls. The straight CNTs display linear current-voltage (I-V) characteristics, indicating diffusive transport rather than ballistic transport. The structural deformation in CNTs with bends substantially increases the resistivity in comparison with that for the straight segments on the same CNTs, and the I-V curve departs slightly from linearity in curved segments. The junction area of the CNT junctions behaves like an ohmic-type scattering center with linear I-V characteristics. In addition, a gating effect has not been observed, in contrast to the case for conventional multi-walled CNT junctions. These unusual transport properties can be attributed to the enhanced inter-layer interaction in the herringbone-type CNTs.

impairs gap junction function causing congenital cataract

Indian Academy of Sciences (India)

LIJUAN CHEN

2017-12-20

Dec 20, 2017 ... showed a lower dye diffusion distance of Cx46 V44M cells, which indicates that the gap junction intercellular ... permeability could be affected by alterations of charged residues of .... bled into gap junction plaques is not soluble in 1% Triton ..... regulation of connexin 43 expression by high glucose reduces.

Fast temporal fluctuations in single-molecule junctions.

Science.gov (United States)

Ochs, Roif; Secker, Daniel; Elbing, Mark; Mayor, Marcel; Weber, Heiko B

2006-01-01

The noise within the electrical current through single-molecule junctions is studied cryogenic temperature. The organic sample molecules were contacted with the mechanically controlled break-junction technique. The noise spectra refer to a where only few Lorentzian fluctuators occur in the conductance. The frequency dependence shows qualitative variations from sample to sample.

Axial p-n-junctions in nanowires.

Science.gov (United States)

Fernandes, C; Shik, A; Byrne, K; Lynall, D; Blumin, M; Saveliev, I; Ruda, H E

2015-02-27

The charge distribution and potential profile of p-n-junctions in thin semiconductor nanowires (NWs) were analyzed. The characteristics of screening in one-dimensional systems result in a specific profile with large electric field at the boundary between the n- and p- regions, and long tails with a logarithmic drop in the potential and charge density. As a result of these tails, the junction properties depend sensitively on the geometry of external contacts and its capacity has an anomalously large value and frequency dispersion. In the presence of an external voltage, electrons and holes in the NWs can not be described by constant quasi-Fermi levels, due to small values of the average electric field, mobility, and lifetime of carriers. Thus, instead of the classical Sah-Noice-Shockley theory, the junction current-voltage characteristic was described by an alternative theory suitable for fast generation-recombination and slow diffusion-drift processes. For the non-uniform electric field in the junction, this theory predicts the forward branch of the characteristic to have a non-ideality factor η several times larger than the values 1 < η < 2 from classical theory. Such values of η have been experimentally observed by a number of researchers, as well as in the present work.

Macroscopic Refrigeration Using Superconducting Tunnel Junctions

Science.gov (United States)

Lowell, Peter; O'Neil, Galen; Underwood, Jason; Zhang, Xiaohang; Ullom, Joel

2014-03-01

Sub-kelvin temperatures are often a prerequisite for modern scientific experiments, such as quantum information processing, astrophysical missions looking for dark energy signatures and tabletop time resolved x-ray spectroscopy. Existing methods of reaching these temperatures, such as dilution refrigerators, are bulky and costly. In order to increase the accessibility of sub-Kelvin temperatures, we have developed a new method of refrigeration using normal-metal/insulator/superconductor (NIS) tunnel junctions. NIS junctions cool the electrons in the normal metal since the hottest electrons selectively tunnel from the normal metal into the superconductor. By extending the normal metal onto a thermally isolated membrane, the cold electrons can cool the phonons through the electron-phonon coupling. When these junctions are combined with a pumped 3He system, they provide a potentially inexpensive method of reaching these temperatures. Using only three devices, each with a junction area of approximately 3,500 μm2, we have cooled a 2 cm3 Cu plate from 290 mK to 256 mK. We will present these experimental results along with recent modeling predictions that strongly suggest that further refinements will allow cooling from 300 mK to 120 mK. This work is supported by the NASA APRA program.

No junctional communication between epithelial cells in hydra

DEFF Research Database (Denmark)

de Laat, S W; Tertoolen, L G; Grimmelikhuijzen, C J

1980-01-01

junctions between epithelial cells of hydra. However, until now, there has been no report published on whether these junctions enable the epithelial cells to exchange molecules of small molecular weight, as has been described in other organisms. Therefore we decided to investigate the communicative...... properties of the junctional membranes by electrophysiological methods and by intracellular-dye iontophoresis. We report here that no electrotonic coupling is detectable between epithelial cells of Hydra attenuata in: (1) intact animals, (2) head-regenerating animals, (3) cell re-aggregates, and (4) hydra...

Spectrum of resonant plasma oscillations in long Josephson junctions

International Nuclear Information System (INIS)

Holst, T.

1996-01-01

An analysis is presented for the amplitude of the plasma oscillations in the zero-voltage state of a long and narrow Josephson tunnel junction. The calculation is valid for arbitrary normalized junction length and arbitrary bias current. The spectrum of the plasma resonance is found numerically as solutions to an analytical equation. The low-frequency part of the spectrum contains a single resonance, which is known to exist also in the limit of a short and narrow junction. Above a certain cutoff frequency, a series of high-frequency standing wave plasma resonances is excited, a special feature of long Josephson junctions. copyright 1996 The American Physical Society

Niobium nitride Josephson tunnel junctions with magnesium oxide barriers

International Nuclear Information System (INIS)

Shoji, A.; Aoyagi, M.; Kosaka, S.; Shinoki, F.; Hayakawa, H.

1985-01-01

Niobium nitride-niobium nitride Josephson tunnel junctions have been fabricated using amorphous magnesium oxide (a-MgO) films as barriers. These junctions have excellent tunneling characteristics. For example, a large gap voltage (V/sub g/ = 5.1 mV), a large product of the maximum critical current and the normal tunneling resistance (I/sub c/R/sub n/ = 3.25 mV), and a small subgap leakage current (V/sub m/ = 45 mV, measured at 3 mV) have been obtained for a NbN/a-MgO/NbN junction. The critical current of this junction remains finite up to 14.5 K

Squeezed States in Josephson Junctions.

Science.gov (United States)

Hu, X.; Nori, F.

1996-03-01

We have studied quantum fluctuation properties of Josephson junctions in the limit of large Josephson coupling energy and small charging energy, when the eigenstates of the system can be treated as being nearly localized. We have considered(X. Hu and F. Nori, preprints.) a Josephson junction in a variety of situations, e.g., coupled to one or several of the following elements: a capacitor, an inductor (in a superconducting ring), and an applied current source. By solving an effective Shrödinger equation, we have obtained squeezed vacuum (coherent) states as the ground states of a ``free-oscillating'' (linearly-driven) Josephson junction, and calculated the uncertainties of its canonical momentum, charge, and coordinate, phase. We have also shown that the excited states of the various systems we consider are similar to the number states of a simple harmonic oscillator but with different fluctuation properties. Furthermore, we have obtained the time-evolution operators for these systems. These operators can make it easier to calculate the time-dependence of the expectation values and fluctuations of various quantities starting from an arbitrary initial state.

Molecular anatomy of interendothelial junctions in human blood-brain barrier microvessels.

Directory of Open Access Journals (Sweden)

Andrzej W Vorbrodt

2004-07-01

Full Text Available Immunogold cytochemical procedure was used to study the localization at the ultrastructural level of interendothelial junction-associated protein molecules in the human brain blood microvessels, representing the anatomic site of the blood-brain barrier (BBB. Ultrathin sections of Lowicryl K4M-embedded biopsy specimens of human cerebral cortex obtained during surgical procedures were exposed to specific antibodies, followed by colloidal gold-labeled secondary antibodies. All tight junction-specific integral membrane (transmembrane proteins--occludin, junctional adhesion molecule (JAM-1, and claudin-5--as well as peripheral zonula occludens protein (ZO-1 were highly expressed. Immunoreactivity of the adherens junction-specific transmembrane protein VE-cadherin was of almost similar intensity. Immunolabeling of the adherens junction-associated peripheral proteins--alpha-catenin, beta-catenin, and p120 catenin--although positive, was evidently less intense. The expression of gamma-catenin (plakoglobin was considered questionable because solitary immunosignals (gold particles appeared in only a few microvascular profiles. Double labeling of some sections made possible to observe strict colocalization of the junctional molecules, such as occludin and ZO-1 or JAM-1 and VE-cadherin, in the interendothelial junctions. We found that in human brain microvessels, the interendothelial junctional complexes contain molecular components specific for both tight and adherens junctions. It is assumed that the data obtained can help us find the immunodetectable junctional molecules that can serve as sensitive markers of normal or abnormal function of the BBB.

Phase-dependent noise in Josephson junctions

Science.gov (United States)

Sheldon, Forrest; Peotta, Sebastiano; Di Ventra, Massimiliano

2018-03-01

In addition to the usual superconducting current, Josephson junctions (JJs) support a phase-dependent conductance related to the retardation effect of tunneling quasi-particles. This introduces a dissipative current with a memory-resistive (memristive) character that should also affect the current noise. By means of the microscopic theory of tunnel junctions we compute the complete current autocorrelation function of a Josephson tunnel junction and show that this memristive component gives rise to both a previously noted phase-dependent thermal noise, and an undescribed non-stationary, phase-dependent dynamic noise. As experiments are approaching ranges in which these effects may be observed, we examine the form and magnitude of these processes. Their phase dependence can be realized experimentally as a hysteresis effect and may be used to probe defects present in JJ based qubits and in other superconducting electronics applications.

Electrical analog of a Josephson junction

International Nuclear Information System (INIS)

Goldman, A.M.

1979-01-01

It is noted that a mathematical description of the phase-coupling of two oscillators synchronized by a phase-lock-loop under the influence of thermal white noise is analogous to that of the phase coupling of two superconductors in a Josephson junction also under the influence of noise. This analogy may be useful in studying threshold instabilities of the Josephson junction in regimes not restricted to the case of large damping. This is of interest because the behavior of the mean voltage near the threshold current can be characterized by critical exponents which resemble those exhibited by an order parameter of a continuous phase transition. As it is possible to couple a collection of oscillators together in a chain, the oscillator analogy may also be useful in exploring the dynamics and statistical mechanics of coupled junctions

Several alternative approaches to the manufacturing of HTS Josephson junctions

OpenAIRE

Villegier , J.; Boucher , H.; Ghis , A.; Levis , M.; Méchin , Laurence; Moriceau , H.; Pourtier , F.; Vabre , M.; Nicoletti , S.; Correra , L.

1994-01-01

In this work we describe comparatively the fabrication and the characterization of various types of HTS Josephson junctions manufactured using different processes : grain boundary junctions have been studied both by the way of junctions on bicrystal substrates and of bi-epitaxial junctions. Ramp-edge types have been elaborated and characterized using mainly N-YBaCuO thin film as a barrier while the trilayer approach has been investigated through a-axis structures. YBaCuO or GdBaCuO supercondu...

The role of Rap1 in cell-cell junction formation

NARCIS (Netherlands)

Kooistra, M.R.H.

2008-01-01

Both epithelial and endothelial cells form cell-cell junctions at the cell-cell contacts to maintain tissue integrity. Proper regulation of cell-cell junctions is required for the organisation of the tissue and to prevent leakage of blood vessels. In endothelial cells, the cell-cell junctions are

Relative impact of short-term emissions controls on gas and particle-phase oxidative potential during the 2015 China Victory Day Parade in Beijing, China

Science.gov (United States)

Huang, Wei; Fang, Dongqing; Shang, Jing; Li, Zhengqiang; Zhang, Yang; Huo, Peng; Liu, Zhaoying; Schauer, James J.; Zhang, Yuanxun

2018-06-01

A field observation focusing on reactive oxygen species (ROS) was conducted before, during, and after the 2015 China Victory Day Parade to understand the influence of short-term emissions controls on atmospheric oxidative activity. The hourly average concentrations of PM2.5, SO2, NO, NO2, CO, O3, as well as gas and particle-phase ROS, were measured using a series of online instruments. PM2.5 concentrations during control days were significantly lower than non-control days, which directly lead to the "Parade Blue", yet reductions of most gaseous pollutants except SO2 were not so obvious as PM. Similarly, the control measures also led to a great loss of particle-phase ROS throughout the control period, while the reduction of ROS in gas phase was not obvious until the more stringent measures implemented since September 1. Furthermore, only weak positive correlations were observed among ROS and some other measured species, indicating ROS concentrations were affected by a number of comprehensive factors that single marker could not capture. Meanwhile, meteorological condition and regional transportation were also shown to be the minor factors affecting atmospheric oxidizing capacity. The results of this observation mainly revealed the control measures were conducive to reducing particle-related ROS. However, the reduction of gas-phase ROS activity was less effective given the menu of controls employed for the 2015 China Victory Day Parade. Therefore, short-term emissions controls only aimed to PM reduction and visibility improvement will produce the blue sky but will not equivalently reduce the gas-phase ROS. Supplemental control measures will be needed to further reduce gas-phase ROS concentrations.

What happens in Josephson junctions at high critical current densities

Science.gov (United States)

Massarotti, D.; Stornaiuolo, D.; Lucignano, P.; Caruso, R.; Galletti, L.; Montemurro, D.; Jouault, B.; Campagnano, G.; Arani, H. F.; Longobardi, L.; Parlato, L.; Pepe, G. P.; Rotoli, G.; Tagliacozzo, A.; Lombardi, F.; Tafuri, F.

2017-07-01

The impressive advances in material science and nanotechnology are more and more promoting the use of exotic barriers and/or superconductors, thus paving the way to new families of Josephson junctions. Semiconducting, ferromagnetic, topological insulator and graphene barriers are leading to unconventional and anomalous aspects of the Josephson coupling, which might be useful to respond to some issues on key problems of solid state physics. However, the complexity of the layout and of the competing physical processes occurring in the junctions is posing novel questions on the interpretation of their phenomenology. We classify some significant behaviors of hybrid and unconventional junctions in terms of their first imprinting, i.e., current-voltage curves, and propose a phenomenological approach to describe some features of junctions characterized by relatively high critical current densities Jc. Accurate arguments on the distribution of switching currents will provide quantitative criteria to understand physical processes occurring in high-Jc junctions. These notions are universal and apply to all kinds of junctions.

An ion-beam-assisted process for high-Tc Josephson junctions

International Nuclear Information System (INIS)

Huang, M.Q.; Chen, L.; Zhao, Z.X.; Yang, T.; Nie, J.C.; Wu, P.J.; Xiong, X.M.

1997-01-01

We have developed a non-ion-etching ion-beam-assisted-deposition (IBAD) process for fabricating high critical-temperature (T c ) grain boundary Josephson junctions through a photoresist liftoff mask. The YBa 2 Cu 3 O 7 (YBCO) junctions fabricated through this process exhibited the resistively-shunted-junction (RSJ)-like I - V characteristics. The well-defined Shapiro steps have been seen on the I - V curves under microwave radiation. The magnetic modulation of critical current of a 4 μm width YBCO junction tallied with the prior simulated Fraunhofer diffraction pattern of a Josephson junction with a spatially homogeneous critical current density. The maximum peak-to-peak modulation voltage across the dc superconducting quantum interference device (SQUID) fabricated by using these junctions reached up to 32 μV at 77 K. The magnetic modulation of the SQUID exhibited periodic behavior with the observed modulation period of 5.0x10 -4 G. copyright 1997 American Institute of Physics

Au nanowire junction breakup through surface atom diffusion

Science.gov (United States)

Vigonski, Simon; Jansson, Ville; Vlassov, Sergei; Polyakov, Boris; Baibuz, Ekaterina; Oras, Sven; Aabloo, Alvo; Djurabekova, Flyura; Zadin, Vahur

2018-01-01

Metallic nanowires are known to break into shorter fragments due to the Rayleigh instability mechanism. This process is strongly accelerated at elevated temperatures and can completely hinder the functioning of nanowire-based devices like e.g. transparent conductive and flexible coatings. At the same time, arranged gold nanodots have important applications in electrochemical sensors. In this paper we perform a series of annealing experiments of gold and silver nanowires and nanowire junctions at fixed temperatures 473, 673, 873 and 973 K (200 °C, 400 °C, 600 °C and 700 °C) during a time period of 10 min. We show that nanowires are especially prone to fragmentation around junctions and crossing points even at comparatively low temperatures. The fragmentation process is highly temperature dependent and the junction region breaks up at a lower temperature than a single nanowire. We develop a gold parametrization for kinetic Monte Carlo simulations and demonstrate the surface diffusion origin of the nanowire junction fragmentation. We show that nanowire fragmentation starts at the junctions with high reliability and propose that aligning nanowires in a regular grid could be used as a technique for fabricating arrays of nanodots.

Flicker (1/f) noise in tunnel junction DC SQUIDS

International Nuclear Information System (INIS)

Koch, R.H.; Clarke, J.; Goubau, W.M.; Martinis, J.M.; Pegrum, C.M.; Van Harlingen, D.J.

1983-01-01

We have measured the spectral density of the 1/f voltage noise in current-biased resistively shunted Josephson tunnel junctions and dc SQUIDs. A theory in which fluctuations in the temperature give rise to fluctuations in the critical current and hence in the voltage predicts the magnitude of the noise quite accurately for junctions with areas of about 2 x 10 4 μm 2 , but significantly overestimates the noise for junctions with areas of about 6 μm 2 . DC SQUIDs fabricated from these two types of junctions exhibit substantially more 1/f voltage noise than would be predicted from a model in which the noise arises from critical current fluctuations in the junctions. This result was confirmed by an experiment involving two different bias current and flux modulation schemes, which demonstrated that the predominant 1/f voltage noise arises not from critical current fluctuations, but from some unknown source that can be regarded as an apparent 1/f flux noise. Measurements on five different configurations of dc SQUIDs fabricated with thin-film tunnel junctions and with widely varying areas, inductances, and junction capacitances show that the spectral density of the 1/f equivalent flux noise is roughtly constant, within a factor of three of (10 -10 /f)phi 2 0 Hz -1 . It is emphasized that 1/f flux noise may not be the predominant source of 1/f noise in SQUIDS fabricated with other technologies

Many-junction photovoltaic device performance under non-uniform high-concentration illumination

Science.gov (United States)

Valdivia, Christopher E.; Wilkins, Matthew M.; Chahal, Sanmeet S.; Proulx, Francine; Provost, Philippe-Olivier; Masson, Denis P.; Fafard, Simon; Hinzer, Karin

2017-09-01

A parameterized 3D distributed circuit model was developed to calculate the performance of III-V solar cells and photonic power converters (PPC) with a variable number of epitaxial vertically-stacked pn junctions. PPC devices are designed with many pn junctions to realize higher voltages and to operate under non-uniform illumination profiles from a laser or LED. Performance impacts of non-uniform illumination were greatly reduced with increasing number of junctions, with simulations comparing PPC devices with 3 to 20 junctions. Experimental results using Azastra Opto's 12- and 20-junction PPC illuminated by an 845 nm diode laser show high performance even with a small gap between the PPC and optical fiber output, until the local tunnel junction limit is reached.

Josephson junctions array resonators

Energy Technology Data Exchange (ETDEWEB)

Gargiulo, Oscar; Muppalla, Phani; Mirzaei, Iman; Kirchmair, Gerhard [Institute for Quantum Optics and Quantum Information, Innsbruck (Austria)

2016-07-01

We present an experimental analysis of the self- and cross-Kerr effect of extended plasma resonances in Josephson junction chains. The chain consists of 1600 individual junctions and we can measure quality factors in excess of 10000. The Kerr effect manifests itself as a frequency shift that depends linearly on the number of photons in a resonant mode. By changing the input power we are able to measure this frequency shift on a single mode (self-kerr). By changing the input power on another mode while measuring the same one, we are able to evaluate the cross-kerr effect. We can measure the cross-Kerr effect by probing the resonance frequency of one mode while exciting another mode of the array with a microwave drive.

Doping enhanced barrier lowering in graphene-silicon junctions

Science.gov (United States)

Zhang, Xintong; Zhang, Lining; Chan, Mansun

2016-06-01

Rectifying properties of graphene-semiconductor junctions depend on the Schottky barrier height. We report an enhanced barrier lowering in graphene-Si junction and its essential doping dependence in this paper. The electric field due to ionized charge in n-type Si induces the same type doping in graphene and contributes another Schottky barrier lowering factor on top of the image-force-induced lowering (IFIL). We confirm this graphene-doping-induced lowering (GDIL) based on well reproductions of the measured reverse current of our fabricated graphene-Si junctions by the thermionic emission theory. Excellent matching between the theoretical predictions and the junction data of the doping-concentration dependent barrier lowering serves as another evidence of the GDIL. While both GDIL and IFIL are enhanced with the Si doping, GDIL exceeds IFIL with a threshold doping depending on the as-prepared graphene itself.

Magnetic properties of slablike Josephson-junction arrays

International Nuclear Information System (INIS)

Chen, D.; Sanchez, A.; Hernando, A.

1994-01-01

Magnetic properties of infinitely long and wide slablike Josephson-junction arrays (JJA's) consisting of 2N+1 rows of grains are calculated for the dc Josephson effect with gauge-invariant phase differences. When N is large, the intergranular magnetization curve, M J (H), of the JJA's in low fields approaches that of uniform Josephson junctions with lengths equal to the thicknesses of the JJA's, but in a larger field interval, its amplitude is dually modulated with periods determined by the junction and void areas. M J (H) curves for small N are more complicated. The concept of Josephson vortices and the application of the results to high-T c superconductors are discussed

Internal resonances in periodically modulated long Josephson junctions

DEFF Research Database (Denmark)

Larsen, Britt Hvolbæk; Mygind, Jesper; Ustinov, Alexey V.

1995-01-01

Current-voltage (I-V) characteristics of long Josephson junctions with a periodic lattice of localized inhomogeneities are studied. The interaction between the moving fluxons and the inhomogeneities causes resonant steps in the IV-curve. Some of these steps are due to a synchronization to resonant...... Fiske modes in the sub-junctions formed between the inhomogeneities. The voltage positions of the resonant steps oscillate as function of the applied magnetic field with a period corresponding to the inclusion of one magnetic flux quantum, Φ0=h/2e, per sub-junction. A qualitative explanation that takes...

Capacitance measurement of Josephson tunnel junctions with microwave-induced dc quasiparticle tunneling currents

International Nuclear Information System (INIS)

Hamasaki, K.; Yoshida, K.; Irie, F.; Enpuku, K.

1982-01-01

The microwave response of the dc quasiparticle tunneling current in Josephson tunnel junctions, where the Josephson current is suppressed by an external magnetic field, has been studied quantitatively in order to clarify its characteristics as a probe for the measurement of the junction capacitance. Extensive experiments for both small and long junctions are carried out for distinguishing between microwave behaviors of lumped and distributed constant junctions. It is shown that the observed voltage dependence of the dc quasiparticle tunneling current modified by an applied rf field is in good agreement with a theoretical result which takes into account the influence of the microwave circuit connected to the junction. The comparison between theory and experiment gives the magnitude of the internal rf field in the junction. Together with the applied rf field, this internal rf field leads to the junction rf impedance which is dominated by the junction capacitance in our experimental condition. In the case of lumped junctions, this experimental rf impedance is in reasonable agreement with the theoretical one with the junction capacitance estimated from the Fiske step of the distributed junction fabricated on the same substrate; the obtained ratio of the experimental impedance to the theoretical one is approximately 0.6--1.7. In the case of distributed junctions, however, experimental values of their characteristic impedances are approximately 0.2--0.3 of theoretical values calculated by assuming the one-dimensional junction model and taking account of the standing-wave effect in the junction

Manufacturing P-N junctions in germanium bodies

International Nuclear Information System (INIS)

Hall, R.N.

1980-01-01

A method of producing p-n junctions in Ge so as to facilitate their use as radiation detectors involves forming a body of high purity p-type germanium, diffusing lithium deep into the body, in the absence of electrolytic processes, to form a junction between n-type and p-type germanium greater than 1 mm depth. (UK)

A first look at the influence of anthropogenic climate change on the future delivery of fluvial sediment to the Ganges-Brahmaputra-Meghna delta.

Science.gov (United States)

Darby, Stephen E; Dunn, Frances E; Nicholls, Robert J; Rahman, Munsur; Riddy, Liam

2015-09-01

We employ a climate-driven hydrological water balance and sediment transport model (HydroTrend) to simulate future climate-driven sediment loads flowing into the Ganges-Brahmaputra-Meghna (GBM) mega-delta. The model was parameterised using high-quality topographic data and forced with daily temperature and precipitation data obtained from downscaled Regional Climate Model (RCM) simulations for the period 1971-2100. Three perturbed RCM model runs were selected to quantify the potential range of future climate conditions associated with the SRES A1B scenario. Fluvial sediment delivery rates to the GBM delta associated with these climate data sets are projected to increase under the influence of anthropogenic climate change, albeit with the magnitude of the increase varying across the two catchments. Of the two study basins, the Brahmaputra's fluvial sediment load is predicted to be more sensitive to future climate change. Specifically, by the middle part of the 21(st) century, our model results suggest that sediment loads increase (relative to the 1981-2000 baseline period) over a range of between 16% and 18% (depending on climate model run) for the Ganges, but by between 25% and 28% for the Brahmaputra. The simulated increase in sediment flux emanating from the two catchments further increases towards the end of the 21(st) century, reaching between 34% and 37% for the Ganges and between 52% and 60% for the Brahmaputra by the 2090s. The variability in these changes across the three climate change simulations is small compared to the changes, suggesting they represent a significant increase. The new data obtained in this study offer the first estimate of whether and how anthropogenic climate change may affect the delivery of fluvial sediment to the GBM delta, informing assessments of the future sustainability and resilience of one of the world's most vulnerable mega-deltas. Specifically, such significant increases in future sediment loads could increase the resilience

Self-positioned thin Pb-alloy base electrode Josephson junction

International Nuclear Information System (INIS)

Kuroda, K.; Sato, K.

1986-01-01

A self-positioned thin (SPOT) Pb-alloy base electrode Josephson junction is developed. In this junction, a 50-nm thick Pb-alloy base electrode is restricted within the junction region on an Nb underlayer using a self-alignment technique. The grain size reduction and the base electrode area restriction greatly improve thermal cycling stability, where the thermal cycling tests of 4000 proposed junctions (5 x 5 μm 2 ) showed no failures after 4000 cycles. In addition, the elimination of insulator layer stress on the Pb-alloy base electrode rectifies the problem of size effect on current density. The Nb underlayers also serve to isolate the Pb-alloy base electrodes from the resistors

High-efficiency thermal switch based on topological Josephson junctions

Science.gov (United States)

Sothmann, Björn; Giazotto, Francesco; Hankiewicz, Ewelina M.

2017-02-01

We propose theoretically a thermal switch operating by the magnetic-flux controlled diffraction of phase-coherent heat currents in a thermally biased Josephson junction based on a two-dimensional topological insulator. For short junctions, the system shows a sharp switching behavior while for long junctions the switching is smooth. Physically, the switching arises from the Doppler shift of the superconducting condensate due to screening currents induced by a magnetic flux. We suggest a possible experimental realization that exhibits a relative temperature change of 40% between the on and off state for realistic parameters. This is a factor of two larger than in recently realized thermal modulators based on conventional superconducting tunnel junctions.

Phonon spectroscopy with superconducting tunnel junctions

International Nuclear Information System (INIS)

Grimshaw, J.M.

1984-02-01

Superconducting tunnel junctions can be used as generators and detectors of monochromatic phonons of frequency larger than 80 GHz, as was first devised by Eisenmenger and Dayem (1967) and Kinder (1972a, 1973). In this report, we intend to give a general outline of this type of spectroscopy and to present the results obtained so far. The basic physics underlying phonon generation and detection are described in chapter I, a wider approach being given in the references therein. In chapter II, the different types of junctions are considered with respect to their use. Chapter III deals with the evaporation technique for the superconducting junctions. The last part of this report is devoted to the results that we have obtained on γ-irradiated LiF, pure Si and Phosphorous implanted Si. In these chapters, the limitations of the spectrometer are brought out and suggestions for further work are given [fr

El consumo de drogas como una práctica cultural dentro de las pandillas O uso de drogas como prática cultural dentro de gangues Drugs use as a cultural practice within gangs

Directory of Open Access Journals (Sweden)

Francisco Rafael Guzmán-Facundo

2011-06-01

Full Text Available Actualmente el fenómeno social del narcotráfico y la violencia relacionada a la drogas ha minimizado las implicaciones del consumo de drogas en pandillas. Este artículo se basa en entrevistas semi-estructuradas a profundidad de un estudio realizado con jóvenes de pandillas del área Metropolitana de Nuevo León, México, con el objetivo de reflexionar y analizar el consumo de drogas como práctica cultural dentro de las pandillas. En la búsqueda del significado, lo primero que se muestra es el inicio de los miembros de pandillas en el consumo de drogas, y se describe la forma en que las drogas le son presentadas por la familia y/o los amigos miembros de la pandilla. Posteriormente se describe el significado del uso de drogas en la vida cotidiana de las pandillas y se observa en qué medida su uso es aceptable y normalizado.O fenômeno social do narcotráfico e da violência, relacionada às drogas, tende, atualmente, a minimizar os envolvimentos do consumo de drogas em gangues. Esse artigo se baseia em entrevistas, aprofundadas, de estudo realizado com jovens de gangues, na área Metropolitana de Nuevo León, México, com o objetivo de refletir e analisar o consumo de drogas como prática cultural, dentro das gangues. Na busca do significado, a primeira coisa mostrada é o início dos membros de gangues no uso de drogas, e se descreve a forma em que as drogas são apresentadas pela família e pelos amigos, membros das gangues. Em seguida, descreve-se o significado do uso de drogas na vida cotidiana e mostra até que ponto sua utilização é aceitável e normal.Today, the social phenomenon of drugs trafficking and violence related to drugs has tended to minimize the implications of drugs consumption in gangs. This article is based on in-depth interviews in young gangs in the metropolitan area of Nuevo León, Mexico, with a view to reflecting on and analyzing the drug as a cultural practice within gangs. In the search for meaning, the first

Breaking into the epithelial apical-junctional complex--news from pathogen hackers.

Science.gov (United States)

Vogelmann, Roger; Amieva, Manuel R; Falkow, Stanley; Nelson, W James

2004-02-01

The epithelial apical-junctional complex is a key regulator of cellular functions. In addition, it is an important target for microbial pathogens that manipulate the cell to survive, proliferate and sometimes persist within a host. Out of a myriad of potential molecular targets, some bacterial and viral pathogens have selected a subset of protein targets at the apical-junctional complex of epithelial cells. Studying how microbes use these targets also teaches us about the inherent physiological properties of host molecules in the context of normal junctional structure and function. Thus, we have learned that three recently uncovered components of the apical-junctional complex of the Ig superfamily--junctional adhesion molecule, Nectin and the coxsackievirus and adenovirus receptor--are important regulators of junction structure and function and represent critical targets of microbial virulence gene products.

Dilute Nitrides For 4-And 6- Junction Space Solar Cells

Science.gov (United States)

Essig, S.; Stammler, E.; Ronsch, S.; Oliva, E.; Schachtner, M.; Siefer, G.; Bett, A. W.; Dimroth, F.

2011-10-01

According to simulations the efficiency of conventional, lattice-matched GaInP/GaInAs/Ge triple-junction space solar cells can be strongly increased by the incorporation of additional junctions. In this way the existing excess current of the Germanium bottom cell can be reduced and the voltage of the stack can be increased. In particular, the use of 1.0 eV materials like GaInNAs opens the door for solar cells with significantly improved conversion efficiency. We have investigated the material properties of GaInNAs grown by metal organic vapour phase epitaxy (MOVPE) and its impact on the quantum efficiency of solar cells. Furthermore we have developed a GaInNAs subcell with a bandgap energy of 1.0 eV and integrated it into a GaInP/GaInAs/GaInNAs/Ge 4-junction and a AlGaInP/GaInP/AlGaInAs/GaInAs/GaInNAs/Ge 6- junction space solar cell. The material quality of the dilute nitride junction limits the current density of these devices to 9.3 mA/cm2 (AM0). This is not sufficient for a 4-junction cell but may lead to current matched 6- junction devices in the future.

Josephson junctions in high-T/sub c/ superconductors

Science.gov (United States)

Falco, C.M.; Lee, T.W.

1981-01-14

The invention includes a high T/sub c/ Josephson sperconducting junction as well as the method and apparatus which provides the junction by application of a closely controlled and monitored electrical discharge to a microbridge region connecting two portions of a superconducting film.

Modeling Bloch oscillations in ultra-small Josephson junctions

Science.gov (United States)

Vora, Heli; Kautz, Richard; Nam, Sae Woo; Aumentado, Jose

In a seminal paper, Likharev et al. developed a theory for ultra-small Josephson junctions with Josephson coupling energy (Ej) less than the charging energy (Ec) and showed that such junctions demonstrate Bloch oscillations which could be used to make a fundamental current standard that is a dual of the Josephson volt standard. Here, based on the model of Geigenmüller and Schön, we numerically calculate the current-voltage relationship of such an ultra-small junction which includes various error processes present in a nanoscale Josephson junction such as random quasiparticle tunneling events and Zener tunneling between bands. This model allows us to explore the parameter space to see the effect of each process on the width and height of the Bloch step and serves as a guide to determine whether it is possible to build a quantum current standard of a metrological precision using Bloch oscillations.

Majorana splitting from critical currents in Josephson junctions

Science.gov (United States)

Cayao, Jorge; San-Jose, Pablo; Black-Schaffer, Annica M.; Aguado, Ramón; Prada, Elsa

2017-11-01

A semiconducting nanowire with strong Rashba spin-orbit coupling and coupled to a superconductor can be tuned by an external Zeeman field into a topological phase with Majorana zero modes. Here we theoretically investigate how this exotic topological superconductor phase manifests in Josephson junctions based on such proximitized nanowires. In particular, we focus on critical currents in the short junction limit (LN≪ξ , where LN is the junction length and ξ is the superconducting coherence length) and show that they contain important information about nontrivial topology and Majoranas. This includes signatures of the gap inversion at the topological transition and a unique oscillatory pattern that originates from Majorana interference. Interestingly, this pattern can be modified by tuning the transmission across the junction, thus providing complementary evidence of Majoranas and their energy splittings beyond standard tunnel spectroscopy experiments, while offering further tunability by virtue of the Josephson effect.

Spatial gradients in freshwater fish diversity, abundance and current pattern in the Himalayan region of Upper Ganges Basin, India

Directory of Open Access Journals (Sweden)

AJEY KUMAR PATHAK

2014-10-01

Full Text Available Pathak AK, Sarkar UK, Singh SP. 2014. Spatial gradients in freshwater fish diversity, abundance and current pattern in the Himalayan region of Upper Ganges Basin, India. Biodiversitas 15: 186-194.The present study describes the analysis and mapping of the different measurements of freshwater fish biodiversity of the Upper Ganges basin in the Himalayan region using spatial interpolation methods of Geographical Information System. The diversity, richness and abundance of fishes for each sampling location were determined and Kriging interpolation was applied on each fisheries measurement to predict and produce semivariogram. The semivariogarms produced were cross validated and reclassified. The reclassified maps for richness, abundance and diversity of fishes, occurrence of cold water threatened fish and abundance of important genera like Tor, Schziothorax and species were produced. The result of the Kriging produced good results and overall error in the estimation process was found significant. The cross validation of semovariograms also provided a better result with the observed data sets. Moreover, weighted overlay analysis of the reclassified raster maps of richness and abundance of fishes produced the classified raster map at different evaluation scale (0-10 qualitatively describing the gradient of species richness and abundance compositely. Similarly, the classified raster map at same evaluation scale qualitatively describing the gradient of species abundance and diversity compositely was produced and published. Further, basin wise analysis between Alaknanda/Pindar and Ganga1 sub basins showed 0.745 disparities at 0.745 distances in 2 dimensional spaces. The richness, diversity and abundance of threatened fishes among the different sampling locations were not significant (p = 0.9.

AlGaAs/InGaAlP tunnel junctions for multijunction solar cells

Energy Technology Data Exchange (ETDEWEB)

SHARPS,P.R.; LI,N.Y.; HILLS,J.S.; HOU,H.; CHANG,PING-CHIH; BACA,ALBERT G.

2000-05-16

Optimization of GaInP{sub 2}/GaAs dual and GaInP{sub 2}/GaAs/Ge triple junction cells, and development of future generation monolithic multi-junction cells will involve the development of suitable high bandgap tunnel junctions. There are three criteria that a tunnel junction must meet. First, the resistance of the junction must be kept low enough so that the series resistance of the overall device is not increased. For AMO, 1 sun operation, the tunnel junction resistance should be below 5 x 10{sup {minus}2} {Omega}-cm. Secondly, the peak current density for the tunnel junction must also be larger than the J{sub sc} of the cell so that the tunnel junction I-V curve does not have a deleterious effect on the I-V curve of the multi-junction device. Finally, the tunnel junction must be optically transparent, i.e., there must be a minimum of optical absorption of photons that will be collected by the underlying subcells. The paper reports the investigation of four high bandgap tunnel junctions grown by metal-organic chemical vapor deposition.

Critical current fluctuation in a microwave-driven Josephson junction

International Nuclear Information System (INIS)

Dong Ning; Sun Guozhu; Wang Yiwen; Cao Junyu; Yu Yang; Chen Jian; Kang Lin; Xu Weiwei; Han Siyuan; Wu Peiheng

2007-01-01

Josephson junction devices are good candidates for quantum computation. A large energy splitting was observed in the spectroscopy of a superconducting Josephson junction. The presence of the critical current fluctuation near the energy splitting indicated coupling between the junction and a two-level system. Furthermore, we find that this fluctuation is microwave dependent. It only appears at certain microwave frequency. This relation suggested that the decoherence of qubits is influenced by the necessary computing operations

Junction Propagation in Organometal Halide Perovskite-Polymer Composite Thin Films.

Science.gov (United States)

Shan, Xin; Li, Junqiang; Chen, Mingming; Geske, Thomas; Bade, Sri Ganesh R; Yu, Zhibin

2017-06-01

With the emergence of organometal halide perovskite semiconductors, it has been discovered that a p-i-n junction can be formed in situ due to the migration of ionic species in the perovskite when a bias is applied. In this work, we investigated the junction formation dynamics in methylammonium lead tribromide (MAPbBr 3 )/polymer composite thin films. It was concluded that the p- and n- doped regions propagated into the intrinsic region with an increasing bias, leading to a reduced intrinsic perovskite layer thickness and the formation of an effective light-emitting junction regardless of perovskite layer thicknesses (300 nm to 30 μm). The junction propagation also played a major role in deteriorating the LED operation lifetime. Stable perovskite LEDs can be achieved by restricting the junction propagation after its formation.

Magnetic field behavior of current steps in long Josephson junctions

International Nuclear Information System (INIS)

Costabile, G.; Cucolo, A.M.; Pace, S.; Parmentier, R.D.; Savo, B.; Vaglio, R.

1980-01-01

The zero-field steps, or dc current singularities, in the current-voltage characteristics of long Josephson tunnel junctions, first reported by Chen et al., continue to attract research interest both because their study can provide fundamental information on the dynamics of fluxons in such junctions and because they are accompanied by the emission of microwave radiation from the junction, which may be exploitable in practical oscillator applications. The purpose of this paper is to report some experimental observations of the magnetic field behavior of the steps in junctions fabricated in our Laboratory and to offer a qualitative explanation for this behavior. Measurements have been made both for very long (L >> lambdasub(J)) and for slightly long (L approx. >= lambdasub(J)) junctions with a view toward comparing our results with those of other workers. (orig./WRI)

Environmental Audit of the Grand Junction Projects Office

Energy Technology Data Exchange (ETDEWEB)

1991-08-01

The Grand Junction Projects Office (GJPO) is located in Mesa County, Colorado, immediately south and west of the Grand Junction city limits. The US Atomic Energy Commission (AEC) established the Colorado Raw Materials Office at the present-day Grand Junction Projects Office in 1947, to aid in the development of a viable domestic uranium industry. Activities at the site included sampling uranium concentrate; pilot-plant milling research, including testing and processing of uranium ores; and operation of a uranium mill pilot plant from 1954 to 1958. The last shipment of uranium concentrate was sent from GJPO in January, 1975. Since that time the site has been utilized to support various DOE programs, such as the former National Uranium Resource Evaluation (NURE) Program, the Uranium Mill Tailings Remedial Action Project (UMTRAP), the Surplus Facilities Management Program (SFMP), and the Technical Measurements Center (TMC). All known contamination at GJPO is believed to be the result of the past uranium milling, analyses, and storage activities. Hazards associated with the wastes impounded at GJPO include surface and ground-water contamination and potential radon and gamma-radiation exposure. This report documents the results of the Baseline Environmental Audit conducted at Grand Junction Projects Office (GJPO) located in Grand Junction, Colorado. The Grand Junction Baseline Environmental Audit was conducted from May 28 to June 12, 1991, by the Office of Environmental Audit (EH-24). This Audit evaluated environmental programs and activities at GJPO, as well as GJPO activities at the State-Owned Temporary Repository. 4 figs., 12 tabs.

Environmental Audit of the Grand Junction Projects Office

International Nuclear Information System (INIS)

1991-08-01

The Grand Junction Projects Office (GJPO) is located in Mesa County, Colorado, immediately south and west of the Grand Junction city limits. The US Atomic Energy Commission (AEC) established the Colorado Raw Materials Office at the present-day Grand Junction Projects Office in 1947, to aid in the development of a viable domestic uranium industry. Activities at the site included sampling uranium concentrate; pilot-plant milling research, including testing and processing of uranium ores; and operation of a uranium mill pilot plant from 1954 to 1958. The last shipment of uranium concentrate was sent from GJPO in January, 1975. Since that time the site has been utilized to support various DOE programs, such as the former National Uranium Resource Evaluation (NURE) Program, the Uranium Mill Tailings Remedial Action Project (UMTRAP), the Surplus Facilities Management Program (SFMP), and the Technical Measurements Center (TMC). All known contamination at GJPO is believed to be the result of the past uranium milling, analyses, and storage activities. Hazards associated with the wastes impounded at GJPO include surface and ground-water contamination and potential radon and gamma-radiation exposure. This report documents the results of the Baseline Environmental Audit conducted at Grand Junction Projects Office (GJPO) located in Grand Junction, Colorado. The Grand Junction Baseline Environmental Audit was conducted from May 28 to June 12, 1991, by the Office of Environmental Audit (EH-24). This Audit evaluated environmental programs and activities at GJPO, as well as GJPO activities at the State-Owned Temporary Repository. 4 figs., 12 tabs

Absolute migration and the evolution of the Rodriguez triple junction ...

African Journals Online (AJOL)

The Rodriguez Triple Junction (RTJ) is a junction connecting three mid-ocean ridges in the Indian Ocean: the Southwest Indian Ridge (SWIR), the Central Indian Ridge (CIR) and the Southeast Indian Ridge (SEIR). The evolution of the RTJ has been studied extensively for the past 10 Ma and the triple junction is believed to ...

Supercurrent and multiple Andreev reflections in micrometer-long ballistic graphene Josephson junctions.

Science.gov (United States)

Zhu, Mengjian; Ben Shalom, Moshe; Mishchsenko, Artem; Fal'ko, Vladimir; Novoselov, Kostya; Geim, Andre

2018-02-08

Ballistic Josephson junctions are predicted to support a number of exotic physics processess, providing an ideal system to inject the supercurrent in the quantum Hall regime. Herein, we demonstrate electrical transport measurements on ballistic superconductor-graphene-superconductor junctions by contacting graphene to niobium with a junction length up to 1.5 μm. Hexagonal boron nitride encapsulation and one-dimensional edge contacts guarantee high-quality graphene Josephson junctions with a mean free path of several micrometers and record-low contact resistance. Transports in normal states including the observation of Fabry-Pérot oscillations and Sharvin resistance conclusively witness the ballistic propagation in the junctions. The critical current density J C is over one order of magnitude larger than that of the previously reported junctions. Away from the charge neutrality point, the I C R N product (I C is the critical current and R N the normal state resistance of junction) is nearly a constant, independent of carrier density n, which agrees well with the theory for ballistic Josephson junctions. Multiple Andreev reflections up to the third order are observed for the first time by measuring the differential resistance in the micrometer-long ballistic graphene Josephson junctions.

Shapiro and parametric resonances in coupled Josephson junctions

International Nuclear Information System (INIS)

Gaafar, Ma A; Shukrinov, Yu M; Foda, A

2012-01-01

The effect of microwave irradiation on the phase dynamics of intrinsic Josephson junctions in high temperature superconductors is investigated. We compare the current-voltage characteristics for a stack of coupled Josephson junctions under external irradiation calculated in the framework of CCJJ and CCJJ+DC models.

Towards molecular electronics with large-area molecular junctions

NARCIS (Netherlands)

Akkerman, HB; Blom, PWM; de Leeuw, DM; de Boer, B

2006-01-01

Electronic transport through single molecules has been studied extensively by academic(1-8) and industrial(9,10) research groups. Discrete tunnel junctions, or molecular diodes, have been reported using scanning probes(11,12), break junctions(13,14), metallic crossbars(6) and nanopores(8,15). For

Chlorpromazine reduces the intercellular communication via gap junctions in mammalian cells

International Nuclear Information System (INIS)

Orellana, Juan A.; Palacios-Prado, Nicolas; Saez, Juan C.

2006-01-01

In the work presented herein, we evaluated the effect of chlorpromazine (CPZ) on gap junctions expressed by two mammalian cell types; Gn-11 cells (cell line derived from mouse LHRH neurons) and rat cortical astrocytes maintained in culture. We also attempted to elucidate possible mechanisms of action of CPZ effects on gap junctions. CPZ, in concentrations comparable with doses used to treat human diseases, was found to reduce the intercellular communication via gap junctions as evaluated with measurements of dye coupling (Lucifer yellow). In both cell types, maximal inhibition of functional gap junctions was reached within about 1 h of treatment with CPZ, an recovery was almost complete at about 5 h after CPZ wash out. In both cell types, CPZ treatment increased the phosphorylation state of connexin43 (Cx43), a gap junction protein subunit. Moreover, CPZ reduced the reactivity of Cx43 (immunofluorescence) at cell interfaces and concomitantly increased its reactivity in intracellular vesicles, suggesting an increased retrieval from and/or reduced insertion into the plasma membrane. CPZ also caused cellular retraction reducing cell-cell contacts in a reversible manner. The reduction in contact area might destabilize existing gap junctions and abrogate formation of new ones. Moreover, the CPZ-induced reduction in gap junctional communication may depend on the connexins (Cxs) forming the junctions. If Cx43 were the only connexin expressed, MAPK-dependent phosphorylation of this connexin would induce closure of gap junction channels

Exotic hadron and string junction model

International Nuclear Information System (INIS)

Imachi, Masahiro

1978-01-01

Hadron structure is investigated adopting string junction model as a realization of confinement. Besides exotic hadrons (M 4 , B 5 etc.), unconventional hadrons appear. A mass formula for these hadrons is proposed. New selection rule is introduced which requires the covalence of constituent line at hadron vertex. New duality appears due to the freedom of junction, especially in anti BB→anti BB reaction. A possible assignment of exotic and unconventional hadrons to recently observed narrow meson states is presented. (auth.)

Perfluoroalkyl substances (PFAS) in river and ground/drinking water of the Ganges River basin: Emissions and implications for human exposure

International Nuclear Information System (INIS)

Sharma, Brij Mohan; Bharat, Girija K.; Tayal, Shresth; Larssen, Thorjørn; Bečanová, Jitka; Karásková, Pavlína; Whitehead, Paul G.; Futter, Martyn N.; Butterfield, Dan; Nizzetto, Luca

2016-01-01

Many perfluoroalkyl substances (PFAS) are ubiquitous environmental contaminants. They have been widely used in production processes and daily-use products or may result from degradation of precursor compounds in products or the environment. India, with its developing industrialization and population moving from traditional to contemporary lifestyles, represents an interesting case study to investigate PFAS emission and exposure along steep environmental and socioeconomic gradients. This study assesses PFAS concentrations in river and groundwater (used in this region as drinking water) from several locations along the Ganges River and estimates direct emissions, specifically for PFOS and PFOA. 15 PFAS were frequently detected in the river with the highest concentrations observed for PFHxA (0.4–4.7 ng L"−"1) and PFBS (< MQL – 10.2 ng L"−"1) among PFCAs and PFSAs, respectively. Prevalence of short-chain PFAS indicates that the effects of PFOA and PFOS substitution are visible in environmental samples from India. The spatial pattern of C_5–C_7 PFCAs co-varied with that of PFOS suggesting similar emission drivers. PFDA and PFNA had much lower concentrations and covaried with PFOA especially in two hotspots downstream of Kanpur and Patna. PFOS and PFOA emissions to the river varied dramatically along the transect (0.20–190 and 0.03–150 g d"−"1, respectively). PFOS emission pattern could be explained by the number of urban residents in the subcatchment (rather than total population). Per-capita emissions were lower than in many developed countries. In groundwater, PFBA (< MQL – 9.2 ng L"−"1) and PFBS (< MQL – 4.9 ng L"−"1) had the highest concentrations among PFCAs and PFSAs, respectively. Concentrations and trends in groundwater were generally similar to those observed in surface water suggesting the aquifer was contaminated by wastewater receiving river water. Daily PFAS exposure intakes through drinking water were below safety

Land-use change may exacerbate climate change impacts on water resources in the Ganges basin

Science.gov (United States)

Tsarouchi, Gina; Buytaert, Wouter

2018-02-01

Quantifying how land-use change and climate change affect water resources is a challenge in hydrological science. This work aims to quantify how future projections of land-use and climate change might affect the hydrological response of the Upper Ganges river basin in northern India, which experiences monsoon flooding almost every year. Three different sets of modelling experiments were run using the Joint UK Land Environment Simulator (JULES) land surface model (LSM) and covering the period 2000-2035: in the first set, only climate change is taken into account, and JULES was driven by the CMIP5 (Coupled Model Intercomparison Project Phase 5) outputs of 21 models, under two representative concentration pathways (RCP4.5 and RCP8.5), whilst land use was held fixed at the year 2010. In the second set, only land-use change is taken into account, and JULES was driven by a time series of 15 future land-use pathways, based on Landsat satellite imagery and the Markov chain simulation, whilst the meteorological boundary conditions were held fixed at years 2000-2005. In the third set, both climate change and land-use change were taken into consideration, as the CMIP5 model outputs were used in conjunction with the 15 future land-use pathways to force JULES. Variations in hydrological variables (stream flow, evapotranspiration and soil moisture) are calculated during the simulation period. Significant changes in the near-future (years 2030-2035) hydrologic fluxes arise under future land-cover and climate change scenarios pointing towards a severe increase in high extremes of flow: the multi-model mean of the 95th percentile of streamflow (Q5) is projected to increase by 63 % under the combined land-use and climate change high emissions scenario (RCP8.5). The changes in all examined hydrological components are greater in the combined land-use and climate change experiment. Results are further presented in a water resources context, aiming to address potential implications of

ACCIDENT PREDICTION MODELS FOR UNSIGNALISED URBAN JUNCTIONS IN GHANA

OpenAIRE

Mohammed SALIFU, MSc., PhD, MIHT, MGhIE

2004-01-01

The main objective of this study was to provide an improved method for safety appraisal in Ghana through the development and application of suitable accident prediction models for unsignalised urban junctions. A case study was designed comprising 91 junctions selected from the two most cosmopolitan cities in Ghana. A wide range of traffic and road data together with the corresponding accident data for each junction for the three-year period 1996-1998 was utilized in the model development p...

Accommodating Grief on Twitter: An Analysis of Expressions of Grief Among Gang Involved Youth on Twitter Using Qualitative Analysis and Natural Language Processing

Science.gov (United States)

Patton, Desmond Upton; MacBeth, Jamie; Schoenebeck, Sarita; Shear, Katherine; McKeown, Kathleen

2018-01-01

There is a dearth of research investigating youths’ experience of grief and mourning after the death of close friends or family. Even less research has explored the question of how youth use social media sites to engage in the grieving process. This study employs qualitative analysis and natural language processing to examine tweets that follow 2 deaths. First, we conducted a close textual read on a sample of tweets by Gakirah Barnes, a gang-involved teenaged girl in Chicago, and members of her Twitter network, over a 19-day period in 2014 during which 2 significant deaths occurred: that of Raason “Lil B” Shaw and Gakirah’s own death. We leverage the grief literature to understand the way Gakirah and her peers express thoughts, feelings, and behaviors at the time of these deaths. We also present and explain the rich and complex style of online communication among gang-involved youth, one that has been overlooked in prior research. Next, we overview the natural language processing output for expressions of loss and grief in our data set based on qualitative findings and present an error analysis on its output for grief. We conclude with a call for interdisciplinary research that analyzes online and offline behaviors to help understand physical and emotional violence and other problematic behaviors prevalent among marginalized communities. PMID:29636619

Phase Sensitive Measurements of Ferromagnetic Josephson Junctions for Cryogenic Memory Applications

Science.gov (United States)

Niedzielski, Bethany Maria

A Josephson junction is made up of two superconducting layers separated by a barrier. The original Josephson junctions, studied in the early 1960's, contained an insulating barrier. Soon thereafter, junctions with normal-metal barriers were also studied. Ferromagnetic materials were not even theoretically considered as a barrier layer until around 1980, due to the competing order between ferromagnetic and superconducting systems. However, many exciting physical phenomena arise in hybrid superconductor/ferromagnetic devices, including devices where the ground state phase difference between the two superconductors is shifted by pi. Since their experimental debut in 2001, so-called pi junctions have been demonstrated by many groups, including my own, in systems with a single ferromagnetic layer. In this type of system, the phase of the junction can be set to either 0 or pi depending on the thickness of the ferromagnetic layer. Of interest, however, is the ability to control the phase of a single junction between the 0 and pi states. This was theoretically shown to be possible in a system containing two ferromagnetic layers (spin-valve junctions). If the materials and their thicknesses are properly chosen to manipulate the electron pair correlation function, then the phase state of a spin-valve Josephson junction should be capable of switching between the 0 and ? phase states when the magnetization directions of the two ferromagnetic layers are oriented in the antiparallel and parallel configurations, respectively. Such a phase-controllable junction would have immediate applications in cryogenic memory, which is a necessary component to an ultra-low power superconducting computer. A fully superconducting computer is estimated to be orders of magnitude more energy-efficient than current semiconductor-based supercomputers. The goal of this work was to experimentally verify this prediction for a phase-controllable ferromagnetic Josephson junction. To address this

Droplet Traffic Control at a simple T junction

Science.gov (United States)

Panizza, Pascal; Engl, Wilfried; Colin, Annie; Ajdari, Armand

2006-03-01

A basic yet essential element of every traffic flow control is the effect of a junction where the flow is separated into several streams. How do pedestrians, vehicles or blood cells divide when they reach a junction? How does the outcome depend on their density? Similar fundamental questions hold for much simpler systems: in this paper, we have studied the behaviour of periodic trains of water droplets flowing in oil through a channel as they reach a simple, locally symmetric, T junction. Depending on their dilution, we observe that the droplets are either alternately partitioned between both outlets or sorted exclusively into the shortest one. We show that this surprising behaviour results from the hydrodynamic feed-back of drops in the two outlets on the selection process occurring at the junction. Our results offer a first guide for the design and modelling of droplet traffic in complex branched networks, a necessary step towards parallelized droplet-based ``lab-on-chip'' devices.

The string-junction picture of multiquark states: an update

Energy Technology Data Exchange (ETDEWEB)

Rossi, G.C. [Dipartimento di Fisica, Università di Roma Tor Vergata, INFN, Sezione di Roma 2, Via della Ricerca Scientifica, 00133 Roma (Italy); Centro Fermi, Museo Storico della Fisica,Piazza del Viminale 1, 00184 Roma (Italy); Veneziano, G. [Collège de France,11 place M. Berthelot, 75005 Paris (France); Theory Division, CERN,CH-1211 Geneva 23 (Switzerland); Dipartimento di Fisica, Università di Roma La Sapienza,Piazzale A. Moro 5, 00185 Roma (Italy)

2016-06-07

We recall and update, both theoretically and phenomenologically, our (nearly) forty-years-old proposal of a string-junction as a necessary complement to the conventional classification of hadrons based just on their quark-antiquark constituents. In that proposal single (though in general metastable) hadronic states are associated with “irreducible' gauge-invariant operators consisting of Wilson lines (visualized as strings of color flux tubes) that may either end on a quark or an antiquark, or annihilate in triplets at a junction J or an anti-junction J̄. For the junction-free sector (ordinary q q̄ mesons and glueballs) the picture is supported by large-N (number of colors) considerations as well as by a lattice strong-coupling expansion. Both imply the famous OZI rule suppressing quark-antiquark annihilation diagrams. For hadrons with J and/or J̄ constituents the same expansions support our proposal, including its generalization of the OZI rule to the suppression of J−J̄ annihilation diagrams. Such a rule implies that hadrons with junctions are “mesophobic' and thus unusually narrow if they are below threshold for decaying into as many baryons as their total number of junctions (two for a tetraquark, three for a pentaquark). Experimental support for our claim, based on the observation that narrow multiquark states typically lie below (well above) the relevant baryonic (mesonic) thresholds, will be presented.

Mixing Hot and Cold Water Streams at a T-Junction

Science.gov (United States)

Sharp, David; Zhang, Mingqian; Xu, Zhenghe; Ryan, Jim; Wanke, Sieghard; Afacan, Artin

2008-01-01

A simple mixing of a hot- and cold-water stream at a T-junction was investigated. The main objective was to use mass and energy balance equations to predict mass low rates and the temperature of the mixed stream after the T-junction, and then compare these with the measured values. Furthermore, the thermocouple location after the T-junction and…

Vortex dynamics in Josephson ladders with II-junctions

DEFF Research Database (Denmark)

Kornev, Victor K.; Klenov, N. V.; Oboznov, V.A.

2004-01-01

Both experimental and numerical studies of a self-frustrated triangular array of pi-junctions are reported. The array of SFS Josephson junctions shows a transition to the pi-state and self-frustration with a decrease in temperature. This manifests itself in a half-period shift of the bias critica...

Optically induced bistable states in metal/tunnel-oxide/semiconductor /MTOS/ junctions

Science.gov (United States)

Lai, S. K.; Dressendorfer, P. V.; Ma, T. P.; Barker, R. C.

1981-01-01

A new switching phenomenon in metal-oxide semiconductor tunnel junction has been discovered. With a sufficiently large negative bias applied to the electrode, incident visible light of intensity greater than about 1 microW/sq cm causes the reverse-biased junction to switch from a low-current to a high-current state. It is believed that hot-electron-induced impact ionization provides the positive feedback necessary for switching, and causes the junction to remain in its high-current state after the optical excitation is removed. The junction may be switched back to the low-current state electrically. The basic junction characteristics have been measured, and a simple model for the switching phenomenon has been developed.

NbN-AlN-NbN Josephson junctions on different substrates

Energy Technology Data Exchange (ETDEWEB)

Merker, Michael; Bohn, Christian; Voellinger, Marvin; Ilin, Konstantin; Siegel, Michael [KIT, Karlsruhe (Germany)

2016-07-01

Josephson junction technology is important for the realization of high quality cryogenic devices such as SQUIDs, RSFQ or SIS-mixers. The material system based on NbN/AlN/NbN tri-layer has gained a lot of interest, because it offers higher gap voltages and critical current densities compared to the well-established Nb/Al-AlOx/Nb technology. However, the realization of high quality Josephson junctions is more challenging. We developed a technology of Josephson junctions on a variety of substrates such as Silicon, Sapphire and Magnesium oxide and compared the quality parameters of these junctions at 4.2 K. The gap voltages achieved a range from 4 mV (for the junctions on Si) to 5.8 mV (in case of MgO substrates) which is considerably higher than those obtained from Nb based Josephson junctions. Another key parameter is the ratio of the subgap resistance to the normal state resistance. This so-called subgap ratio corresponds to the losses in a Josephson junction which have to be minimized. So far, subgap ratios of 26 have been achieved. Further careful optimization of the deposition conditions is required to maximize this ratio, The details of the optimization of technology and of characterization of NbN/AlN/NbN junctions will be presented and discussed.

Superconducting tunnel-junction refrigerator

International Nuclear Information System (INIS)

Melton, R.G.; Paterson, J.L.; Kaplan, S.B.

1980-01-01

The dc current through an S 1 -S 2 tunnel junction, with Δ 2 greater than Δ 1 , when biased with eV 1 +Δ 2 , will lower the energy in S 1 . This energy reduction will be shared by the phonons and electrons. This device is shown to be analogous to a thermoelectric refrigerator with an effective Peltier coefficient π* approx. Δ 1 /e. Tunneling calculations yield the cooling power P/sub c/, the electrical power P/sub e/ supplied by the bias supply, and the cooling efficiency eta=P/sub c//P/sub e/. The maximum cooling power is obtained for eV= +- (Δ 2 -Δ 1 ) and t 1 =T 1 /T/sub c/1 approx. 0.9. Estimates are made of the temperature difference T 2 -T 1 achievable in Al-Pb and Sn-Pb junctions with an Al 2 O 3 tunneling barrier. The performance of this device is shown to yield a maximum cooling efficiency eta approx. = Δ 1 /(Δ 2 -Δ 1 ) which can be compared with that available in an ideal Carnot refrigerator of eta=T 1 /(T 2 -T 1 ). The development of a useful tunnel-junction refrigerator requires a tunneling barrier with an effective thermal conductance per unit area several orders of magnitude less than that provided by the A1 2 O 3 barrier in the Al-Pb and Sn-Pb systems

Marker of cemento-periodontal ligament junction associated with periodontal regeneration.

Science.gov (United States)

Hara, Ryohko; Wato, Masahiro; Tanaka, Akio

2005-06-01

The purpose of this study was to identify factors promoting formation of the cemento-periodontal ligament junction. Regeneration of the cemento-periodontal ligament junction is an important factor in recovery of the connective tissue attachment to the cementum and it is important to identify all specific substances that promote its formation. To clarify the substances involved in cemento-periodontal ligament junction formation, we produced a monoclonal antibody (mAb) to human cemento-periodontal ligament junction (designated as the anti-TAP mAb) and examined its immunostaining properties and reactive antigen. Hybridomas producing monoclonal antibody against human cemento-periodontal ligament junction antigens were established by fusing P3U1 mouse myeloma cells with spleen cells from BALB/c mice immunized with homogenized human cemento-periodontal ligament junction. The mAb, the anti-TAP mAb for cemento-periodontal ligament junction, was then isolated. The immunoglobulin class and light chain of the mAb were examined using an isotyping kit. Before immunostaining, antigen determination using an enzymatic method or heating was conducted. Human teeth, hard tissue-forming lesions, and animal tissues were immunostained by the anti-TAP mAb. The anti-TAP mAb was positive in human cemento-periodontal ligament junction and predentin but negative in all other human and animal tissues examined. In the cemento-osseous lesions, the anti-TAP mAb was positive in the peripheral area of the cementum and cementum-like hard tissues and not in the bone and bone-like tissues. The anti-TAP mAb showed IgM (kappa) and recognized phosphoprotein. The anti-TAP mAb is potentially useful for developing new agents promoting cementogenesis and periodontal regeneration.

A numerical model of p-n junctions bordering on surfaces

Energy Technology Data Exchange (ETDEWEB)

Altermatt, P.P.; Aberle, A.G.; Jianhua Zhao; Aihua Wang; Heiser, G. [University of New South Wales, Sydney (Australia). Centre for Photovolatic Engineering

2002-10-01

Many solar cell structures contain regions where the emitter p-n junction borders on the surface. If the surface is not well passivated, a large amount of recombination occurs in such regions. This type of recombination is influenced by the electrostatics of both the p-n junction and the surface, and hence it is different from the commonly described recombination phenomena occurring in the p-n junction within the bulk. We developed a two-dimensional model for the recombination mechanisms occurring in emitter p-n junctions bordering on surfaces. The model is validated by reproducing the experimental I-V curves of specially designed silicon solar cells. It is shown under which circumstances a poor surface passivation, near where the p-n junction borders on the surface, reduces the fill factor and the open-circuit voltage. The model can be applied to many other types of solar cells. (author)

Preparation of CN /Carbon Nanotube Intramolecular Junctions by ...

African Journals Online (AJOL)

NICO

intramolecular junctions composed of CNx with a bamboo-like structure and empty hollow carbon nanotubes were observed, ... and excellent thermal and mechanical properties.1,2 In recent .... tion of hexane, and the other segment with a curved compart- ... by an arrow lies at the interface of the junction between 'b' and.

Systematic optimization of quantum junction colloidal quantum dot solar cells

KAUST Repository

Liu, Huan

2012-01-01

The recently reported quantum junction architecture represents a promising approach to building a rectifying photovoltaic device that employs colloidal quantum dot layers on each side of the p-n junction. Here, we report an optimized quantum junction solar cell that leverages an improved aluminum zinc oxide electrode for a stable contact to the n-side of the quantum junction and silver doping of the p-layer that greatly enhances the photocurrent by expanding the depletion region in the n-side of the device. These improvements result in greater stability and a power conversion efficiency of 6.1 under AM1.5 simulated solar illumination. © 2012 American Institute of Physics.

Proliferation of sharp kinks on cosmic (super)string loops with junctions

International Nuclear Information System (INIS)

Binetruy, P.; Bohe, A.; Hertog, T.; Steer, D. A.

2010-01-01

Motivated by their effect on the gravitational wave signal emitted by cosmic strings, we study the dynamics of kinks on strings of different tensions meeting at junctions. The propagation of a kink through a Y junction leads to the formation of three 'daughter' kinks. Assuming a uniform distribution of the incoming wave vectors at the junction, we find there is a significant region of configuration space in which the sharpness of at least one of the daughter kinks is enhanced relative to the sharpness of the initial kink. For closed loops with junctions we show this leads to an exponential growth in time of very sharp kinks. Using numerical simulations of realistic, evolving cosmic string loops with junctions to calculate the distribution of kink amplitudes as a function of time, we show that loops of this kind typically develop several orders of magnitude of very sharp kinks before the two junctions collide. This collision, or other effects such as gravitational backreaction, may end the proliferation.

Field-In-Field Technique With Intrafractionally Modulated Junction Shifts for Craniospinal Irradiation

International Nuclear Information System (INIS)

Yom, Sue S.; Frija, Erik K. C.; Mahajan, Anita; Chang, Eric; Klein, Kelli C.; Shiu, Almon; Ohrt, Jared; Woo, Shiao

2007-01-01

Purpose: To plan craniospinal irradiation with 'field-in-field' (FIF) homogenization in combination with daily, intrafractional modulation of the field junctions, to minimize the possibility of spinal cord overdose. Methods and Materials: Lateral cranial fields and posterior spinal fields were planned using a forward-planned, step-and-shoot FIF technique. Field junctions were automatically modulated and custom-weighted for maximal homogeneity within each treatment fraction. Dose-volume histogram analyses and film dosimetry were used to assess results. Results: Plan inhomogeneity improved with FIF. Planning with daily modulated junction shifts provided consistent dose delivery during each fraction of treatment across the junctions. Modulation minimized the impact of a 5-mm setup error at the junction. Film dosimetry confirmed that no point in the junction exceeded the anticipated dose. Conclusions: Field-in-field planning and modulated junction shifts improve the homogeneity and consistency of daily dose delivery, simplify treatment, and reduce the impact of setup errors

Direct analysis of Holliday junction resolving enzyme in a DNA origami nanostructure.

Science.gov (United States)

Suzuki, Yuki; Endo, Masayuki; Cañas, Cristina; Ayora, Silvia; Alonso, Juan C; Sugiyama, Hiroshi; Takeyasu, Kunio

2014-06-01

Holliday junction (HJ) resolution is a fundamental step for completion of homologous recombination. HJ resolving enzymes (resolvases) distort the junction structure upon binding and prior cleavage, raising the possibility that the reactivity of the enzyme can be affected by a particular geometry and topology at the junction. Here, we employed a DNA origami nano-scaffold in which each arm of a HJ was tethered through the base-pair hybridization, allowing us to make the junction core either flexible or inflexible by adjusting the length of the DNA arms. Both flexible and inflexible junctions bound to Bacillus subtilis RecU HJ resolvase, while only the flexible junction was efficiently resolved into two duplexes by this enzyme. This result indicates the importance of the structural malleability of the junction core for the reaction to proceed. Moreover, cleavage preferences of RecU-mediated reaction were addressed by analyzing morphology of the reaction products. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

GaAs nanowire array solar cells with axial p-i-n junctions.

Science.gov (United States)

Yao, Maoqing; Huang, Ningfeng; Cong, Sen; Chi, Chun-Yung; Seyedi, M Ashkan; Lin, Yen-Ting; Cao, Yu; Povinelli, Michelle L; Dapkus, P Daniel; Zhou, Chongwu

2014-06-11

Because of unique structural, optical, and electrical properties, solar cells based on semiconductor nanowires are a rapidly evolving scientific enterprise. Various approaches employing III-V nanowires have emerged, among which GaAs, especially, is under intense research and development. Most reported GaAs nanowire solar cells form p-n junctions in the radial direction; however, nanowires using axial junction may enable the attainment of high open circuit voltage (Voc) and integration into multijunction solar cells. Here, we report GaAs nanowire solar cells with axial p-i-n junctions that achieve 7.58% efficiency. Simulations show that axial junctions are more tolerant to doping variation than radial junctions and lead to higher Voc under certain conditions. We further study the effect of wire diameter and junction depth using electrical characterization and cathodoluminescence. The results show that large diameter and shallow junctions are essential for a high extraction efficiency. Our approach opens up great opportunity for future low-cost, high-efficiency photovoltaics.

Contour junctions defined by dynamic image deformations enhance perceptual transparency.

Science.gov (United States)

Kawabe, Takahiro; Nishida, Shin'ya

2017-11-01

The majority of work on the perception of transparency has focused on static images with luminance-defined contour junctions, but recent work has shown that dynamic image sequences with dynamic image deformations also provide information about transparency. The present study demonstrates that when part of a static image is dynamically deformed, contour junctions at which deforming and nondeforming contours are connected facilitate the deformation-based perception of a transparent layer. We found that the impression of a transparent layer was stronger when a dynamically deforming area was adjacent to static nondeforming areas than when presented alone. When contour junctions were not formed at the dynamic-static boundaries, however, the impression of a transparent layer was not facilitated by the presence of static surrounding areas. The effect of the deformation-defined junctions was attenuated when the spatial pattern of luminance contrast at the junctions was inconsistent with the perceived transparency related to luminance contrast, while the effect did not change when the spatial luminance pattern was consistent with it. In addition, the results showed that contour completions across the junctions were required for the perception of a transparent layer. These results indicate that deformation-defined junctions that involve contour completion between deforming and nondeforming regions enhance the perception of a transparent layer, and that the deformation-based perceptual transparency can be promoted by the simultaneous presence of appropriately configured luminance and contrast-other features that can also by themselves produce the sensation of perceiving transparency.

Proposed differential-frequency-readout system by hysteretic Josephson junctions

International Nuclear Information System (INIS)

Wang, L.Z.; Duncan, R.V.

1992-01-01

The Josephson relation V=nhν/2e has been verified experimentally to 3 parts in 10 19 [A. K. Jain, J. E. Lukens, and J.-S. Tsai, Phys. Rev. Lett. 58, 1165 (1987)]. Motivated by this result, we propose a differential-frequency-readout system by two sets of hysteretic Josephson junctions rf biased at millimeter wavelengths. Because of the Josephson relation, the proposed differential-frequency-readout system is not limited by photon fluctuation, which limits most photon-detection schemes. In the context of the Stewart-McCumber model [W. C. Stewart, Appl. Phys. Lett. 12, 277 (1968); D. E. McCumber, J. Appl. Phys. 39, 3113 (1968)] of Josephson junctions, we show theoretically that the differential frequency of the two milliwave biases can be read out by the proposed system to unprecedented accuracy. The stability of the readout scheme is also discussed. The measurement uncertainty of the readout system resulting from the intrinsic thermal noise in the hysteretic junctions is shown to be insignificant. The study of two single junctions can be extended to two sets of Josephson junctions connected in series (series array) in this measurement scheme provided that junctions are separated by at least 10 μm [D. W. Jillie, J. E. Lukens, and Y. H. Kao, Phys. Rev. Lett. 38, 915 (1977)]. The sensitivity for the differential frequency detection may be increased by biasing both series arrays to a higher constant-voltage step

Human zonulin, a potential modulator of intestinal tight junctions.

Science.gov (United States)

Wang, W; Uzzau, S; Goldblum, S E; Fasano, A

2000-12-01

Intercellular tight junctions are dynamic structures involved in vectorial transport of water and electrolytes across the intestinal epithelium. Zonula occludens toxin derived from Vibrio cholerae interacts with a specific intestinal epithelial surface receptor, with subsequent activation of a complex intracellular cascade of events that regulate tight junction permeability. We postulated that this toxin may mimic the effect of a functionally and immunologically related endogenous modulator of intestinal tight junctions. Affinity-purified anti-zonula occludens toxin antibodies and the Ussing chamber assay were used to screen for one or more mammalian zonula occludens toxin analogues in both fetal and adult human intestine. A novel protein, zonulin, was identified that induces tight junction disassembly in non-human primate intestinal epithelia mounted in Ussing chambers. Comparison of amino acids in the active zonula occludens toxin fragment and zonulin permitted the identification of the putative receptor binding domain within the N-terminal region of the two proteins. Zonulin likely plays a pivotal role in tight junction regulation during developmental, physiological, and pathological processes, including tissue morphogenesis, movement of fluid, macromolecules and leukocytes between the intestinal lumen and the interstitium, and inflammatory/autoimmune disorders.

Large eddy simulation of a wing-body junction flow

Science.gov (United States)

Ryu, Sungmin; Emory, Michael; Campos, Alejandro; Duraisamy, Karthik; Iaccarino, Gianluca

2014-11-01

We present numerical simulations of the wing-body junction flow experimentally investigated by Devenport & Simpson (1990). Wall-junction flows are common in engineering applications but relevant flow physics close to the corner region is not well understood. Moreover, performance of turbulence models for the body-junction case is not well characterized. Motivated by the insufficient investigations, we have numerically investigated the case with Reynolds-averaged Naiver-Stokes equation (RANS) and Large Eddy Simulation (LES) approaches. The Vreman model applied for the LES and SST k- ω model for the RANS simulation are validated focusing on the ability to predict turbulence statistics near the junction region. Moreover, a sensitivity study of the form of the Vreman model will also be presented. This work is funded under NASA Cooperative Agreement NNX11AI41A (Technical Monitor Dr. Stephen Woodruff)

Mechanical break junctions: enormous information in a nanoscale package.

Science.gov (United States)

Natelson, Douglas

2012-04-24

Mechanical break junctions, particularly those in which a metal tip is repeatedly moved in and out of contact with a metal film, have provided many insights into electronic conduction at the atomic and molecular scale, most often by averaging over many possible junction configurations. This averaging throws away a great deal of information, and Makk et al. in this issue of ACS Nano demonstrate that, with both simulated and real experimental data, more sophisticated two-dimensional analysis methods can reveal information otherwise obscured in simple histograms. As additional measured quantities come into play in break junction experiments, including thermopower, noise, and optical response, these more sophisticated analytic approaches are likely to become even more powerful. While break junctions are not directly practical for useful electronic devices, they are incredibly valuable tools for unraveling the electronic transport physics relevant for ultrascaled nanoelectronics.

BPS dynamics of the triple (p,q) string junction

International Nuclear Information System (INIS)

Rey, S.-J.; Yee, J.-T.

1998-01-01

We study the dynamics of the triple junction of (p,q) strings in type IIB string theory. We probe the tension and mass density of (p,q) strings by studying harmonic fluctuations of the triple junction. We show that they agree perfectly with the BPS formula provided a suitable geometric interpretation of the junction is given. We provide a precise statement of the BPS limit and force-balance property. At weak coupling and sufficiently dense limit, we argue that a (p,q) string embedded in the string network is a 'wiggly string', whose low-energy dynamics can be described via a renormalization group evolved, smooth effective non-relativistic string. We also suggest the possibility that, upon type IIB strings being promoted to the M-theory membrane, there can exist 'evanescent' bound-states at the triple junction in the continuum. (orig.)

Symmetry breaking in SNS junctions: edge transport and field asymmetries

Science.gov (United States)

Suominen, Henri; Nichele, Fabrizio; Kjaergaard, Morten; Rasmussen, Asbjorn; Danon, Jeroen; Flensberg, Karsten; Levitov, Leonid; Shabani, Javad; Palmstrom, Chris; Marcus, Charles

We study magnetic diffraction patterns in a tunable superconductor-semiconductor-superconductor junction. By utilizing epitaxial growth of aluminum on InAs/InGaAs we obtain transparent junctions which display a conventional Fraunhofer pattern of the critical current as a function of applied perpendicular magnetic field, B⊥. By studying the angular dependence of the critical current with applied magnetic fields in the plane of the junction we find a striking anisotropy. We attribute this effect to dephasing of Andreev states in the bulk of the junction, leading to SQUID like behavior when the magnetic field is applied parallel to current flow. Furthermore, in the presence of both in-plane and perpendicular fields, asymmetries in +/-B⊥ are observed. We suggest possible origins and discuss the role of spin-orbit and Zeeman physics together with a background disorder potential breaking spatial symmetries of the junction. Research supported by Microsoft Project Q, the Danish National Research Foundation and the NSF through the National Nanotechnology Infrastructure Network.

Charge splitters and charge transport junctions based on guanine quadruplexes

Science.gov (United States)

Sha, Ruojie; Xiang, Limin; Liu, Chaoren; Balaeff, Alexander; Zhang, Yuqi; Zhang, Peng; Li, Yueqi; Beratan, David N.; Tao, Nongjian; Seeman, Nadrian C.

2018-04-01

Self-assembling circuit elements, such as current splitters or combiners at the molecular scale, require the design of building blocks with three or more terminals. A promising material for such building blocks is DNA, wherein multiple strands can self-assemble into multi-ended junctions, and nucleobase stacks can transport charge over long distances. However, nucleobase stacking is often disrupted at junction points, hindering electric charge transport between the two terminals of the junction. Here, we show that a guanine-quadruplex (G4) motif can be used as a connector element for a multi-ended DNA junction. By attaching specific terminal groups to the motif, we demonstrate that charges can enter the structure from one terminal at one end of a three-way G4 motif, and can exit from one of two terminals at the other end with minimal carrier transport attenuation. Moreover, we study four-way G4 junction structures by performing theoretical calculations to assist in the design and optimization of these connectors.

E-cadherin junction formation involves an active kinetic nucleation process

Science.gov (United States)

Biswas, Kabir H.; Hartman, Kevin L.; Yu, Cheng-han; Harrison, Oliver J.; Song, Hang; Smith, Adam W.; Huang, William Y. C.; Lin, Wan-Chen; Guo, Zhenhuan; Padmanabhan, Anup; Troyanovsky, Sergey M.; Dustin, Michael L.; Shapiro, Lawrence; Honig, Barry; Zaidel-Bar, Ronen; Groves, Jay T.

2015-01-01

Epithelial (E)-cadherin-mediated cell−cell junctions play important roles in the development and maintenance of tissue structure in multicellular organisms. E-cadherin adhesion is thus a key element of the cellular microenvironment that provides both mechanical and biochemical signaling inputs. Here, we report in vitro reconstitution of junction-like structures between native E-cadherin in living cells and the extracellular domain of E-cadherin (E-cad-ECD) in a supported membrane. Junction formation in this hybrid live cell-supported membrane configuration requires both active processes within the living cell and a supported membrane with low E-cad-ECD mobility. The hybrid junctions recruit α-catenin and exhibit remodeled cortical actin. Observations suggest that the initial stages of junction formation in this hybrid system depend on the trans but not the cis interactions between E-cadherin molecules, and proceed via a nucleation process in which protrusion and retraction of filopodia play a key role. PMID:26290581

Tunnel magnetoresistance in double spin filter junctions

International Nuclear Information System (INIS)

Saffarzadeh, Alireza

2003-01-01

We consider a new type of magnetic tunnel junction, which consists of two ferromagnetic tunnel barriers acting as spin filters (SFs), separated by a nonmagnetic metal (NM) layer. Using the transfer matrix method and the free-electron approximation, the dependence of the tunnel magnetoresistance (TMR) on the thickness of the central NM layer, bias voltage and temperature in the double SF junction are studied theoretically. It is shown that the TMR and electron-spin polarization in this structure can reach very large values under suitable conditions. The highest value of the TMR can reach 99%. By an appropriate choice of the thickness of the central NM layer, the degree of spin polarization in this structure will be higher than that of the single SF junctions. These results may be useful in designing future spin-polarized tunnelling devices

Breaking gold nano-junctions simulation and analysis

DEFF Research Database (Denmark)

Lauritzen, Kasper Primdal

, to predict the structure of a gold junction just as it breaks. This method is based on artificial neural networks and can be used on experimental data, even when it is trained purely on simulated data. The method is extended to other types of experimental traces, where it is trained without the use......Simulating the movements of individual atoms allows us to look at and investigate the physical processes that happen in an experiment. In this thesis I use simulations to support and improve experimental studies of breaking gold nano-junctions. By using molecular dynamics to study gold nanowires, I...... can investigate their breaking forces under varying conditions, like stretching rate or temperature. This resolves a confusion in the literature, where the breaking forces of two different breaking structures happen to coincide. The correlations between the rupture and reformation of a gold junction...

Membrane junctions in Xenopus eggs: their distribution suggests a role in calcium regulation.

Science.gov (United States)

Gardiner, D M; Grey, R D

1983-04-01

We have observed the presence of membrane junctions formed between the plasma membrane and cortical endoplasmic reticulum of mature, unactivated eggs of xenopus laevis. The parallel, paired membranes of the junction are separated by a 10-mn gap within which electron-dense material is present. This material occurs in patches with an average center-to-center distance of approximately 30 nm. These junctions are rare in immature (but fully grown) oocytes (approximately 2 percent of the plasma membrane is associated with junctions) and increase dramatically during progesterone-induced maturation. Junctions in the mature, unactivated egg are two to three times more abundant in the animal hemisphere (25-30 percent of the plasma membrane associated with junction) as compared with the vegetal hemisphere (10-15 percent). Junction density decreases rapidly to values characteristic of immature oocytes in response to egg activation. The plasma membrane-ER junctions of xenopus eggs are strikingly similar in structure to membrane junctions in muscle cells thought to be essential in the triggering of intracellular calcium release from the sarcoplasmic reticulum. In addition, the junctions' distinctive, animal-vegetal polarity of distribution, their dramatic appearance during maturation, and their disapperance during activation are correlated with previously documented patterns of calcium-mediated events in anuran eggs. We discuss several lines of evidence supporting the hypothesis that these junctions in xenopus eggs are sites that transduce extracellular events into intracellular calcium release during fertilization and activation of development.

Stretching of BDT-gold molecular junctions: Thiol or thiolate termination?

KAUST Repository

Souza, Amaury De Melo; Rungger, Ivan; Pontes, Renato Borges; Rocha, Alexandre Reily; Da Silva, Antô nio José Roque; Schwingenschlö gl, Udo; Sanvito, S.

2014-01-01

It is often assumed that the hydrogen atoms in the thiol groups of a benzene-1,4-dithiol dissociate when Au-benzene-1,4-dithiol-Au junctions are formed. We demonstrate, by stability and transport property calculations, that this assumption cannot be made. We show that the dissociative adsorption of methanethiol and benzene-1,4-dithiol molecules on a flat Au(111) surface is energetically unfavorable and that the activation barrier for this reaction is as high as 1 eV. For the molecule in the junction, our results show, for all electrode geometries studied, that the thiol junctions are energetically more stable than their thiolate counterparts. Due to the fact that density functional theory (DFT) within the local density approximation (LDA) underestimates the energy difference between the lowest unoccupied molecular orbital and the highest occupied molecular orbital by several electron-volts, and that it does not capture the renormalization of the energy levels due to the image charge effect, the conductance of the Au-benzene-1,4-dithiol-Au junctions is overestimated. After taking into account corrections due to image charge effects by means of constrained-DFT calculations and electrostatic classical models, we apply a scissor operator to correct the DFT energy level positions, and calculate the transport properties of the thiol and thiolate molecular junctions as a function of the electrode separation. For the thiol junctions, we show that the conductance decreases as the electrode separation increases, whereas the opposite trend is found for the thiolate junctions. Both behaviors have been observed in experiments, therefore pointing to the possible coexistence of both thiol and thiolate junctions. Moreover, the corrected conductance values, for both thiol and thiolate, are up to two orders of magnitude smaller than those calculated with DFT-LDA. This brings the theoretical results in quantitatively good agreement with experimental data.

Steady-state properties of Josephson junctions with direct conductivity

International Nuclear Information System (INIS)

Zubkov, A.A.; Kupriyanov, M.Y.; Semenov, V.K.

1981-01-01

A new criterion for determining the kinetic inductance of Josephson junctions is introduced. The effects of temperature T, the critical temperatures of the superconducting electrodes T/sub c/1 and T/sub c/2, and the weak-link length on the kinetic inductance of ''dirty'' junctions with direct conductivity are analyzed within the framework of the Usadel equations. Numerical calculations show that both a large characteristic voltage and a nearly harmonic dependence of the current on the phase difference of the superconducting-electrode wave functions cannot be obtained by varying the junction parameters

Spin-transfer torque in spin filter tunnel junctions

KAUST Repository

Ortiz Pauyac, Christian

2014-12-08

Spin-transfer torque in a class of magnetic tunnel junctions with noncollinear magnetizations, referred to as spin filter tunnel junctions, is studied within the tight-binding model using the nonequilibrium Green\\'s function technique within Keldysh formalism. These junctions consist of one ferromagnet (FM) adjacent to a magnetic insulator (MI) or two FM separated by a MI. We find that the presence of the magnetic insulator dramatically enhances the magnitude of the spin-torque components compared to conventional magnetic tunnel junctions. The fieldlike torque is driven by the spin-dependent reflection at the MI/FM interface, which results in a small reduction of its amplitude when an insulating spacer (S) is inserted to decouple MI and FM layers. Meanwhile, the dampinglike torque is dominated by the tunneling electrons that experience the lowest barrier height. We propose a device of the form FM/(S)/MI/(S)/FM that takes advantage of these characteristics and allows for tuning the spin-torque magnitudes over a wide range just by rotation of the magnetization of the insulating layer.

Spin-transfer torque in spin filter tunnel junctions

KAUST Repository

Ortiz Pauyac, Christian; Kalitsov, Alan; Manchon, Aurelien; Chshiev, Mairbek

2014-01-01

Spin-transfer torque in a class of magnetic tunnel junctions with noncollinear magnetizations, referred to as spin filter tunnel junctions, is studied within the tight-binding model using the nonequilibrium Green's function technique within Keldysh formalism. These junctions consist of one ferromagnet (FM) adjacent to a magnetic insulator (MI) or two FM separated by a MI. We find that the presence of the magnetic insulator dramatically enhances the magnitude of the spin-torque components compared to conventional magnetic tunnel junctions. The fieldlike torque is driven by the spin-dependent reflection at the MI/FM interface, which results in a small reduction of its amplitude when an insulating spacer (S) is inserted to decouple MI and FM layers. Meanwhile, the dampinglike torque is dominated by the tunneling electrons that experience the lowest barrier height. We propose a device of the form FM/(S)/MI/(S)/FM that takes advantage of these characteristics and allows for tuning the spin-torque magnitudes over a wide range just by rotation of the magnetization of the insulating layer.

Neutron induced permanent damage in Josephson junctions

International Nuclear Information System (INIS)

Mueller, G.P.; Rosen, M.

1982-01-01

14 MeV neutron induced permanent changes in the critical current density of Josephson junctions due to displacement damage in the junction barrier are estimated using a worst case model and the binary collision simulation code MARLOWE. No likelihood of single event hard upsets is found in this model. It is estimated that a fluence of 10 18 -10 19 neutrons/cm 2 are required to change the critical current density by 5%

Spinal Gap Junction Channels in Neuropathic Pain

OpenAIRE

Jeon, Young Hoon; Youn, Dong Ho

2015-01-01

Damage to peripheral nerves or the spinal cord is often accompanied by neuropathic pain, which is a complex, chronic pain state. Increasing evidence indicates that alterations in the expression and activity of gap junction channels in the spinal cord are involved in the development of neuropathic pain. Thus, this review briefly summarizes evidence that regulation of the expression, coupling, and activity of spinal gap junction channels modulates pain signals in neuropathic pain states induced...

Junction temperature estimation for an advanced active power cycling test

DEFF Research Database (Denmark)

Choi, Uimin; Blaabjerg, Frede; Jørgensen, S.

2015-01-01

estimation method using on-state VCE for an advanced active power cycling test is proposed. The concept of the advanced power cycling test is explained first. Afterwards the junction temperature estimation method using on-state VCE and current is presented. Further, the method to improve the accuracy...... of the maximum junction temperature estimation is also proposed. Finally, the validity and effectiveness of the proposed method is confirmed by experimental results.......On-state collector-emitter voltage (VCE) is a good indicator to determine the wear-out condition of power device modules. Further, it is a one of the Temperature Sensitive Electrical Parameters (TSEPs) and thus can be used for junction temperature estimation. In this paper, the junction temperature...

Photovoltaic Cells Improvised With Used Bipolar Junction Transistors

International Nuclear Information System (INIS)

Akintayo, J. A

2002-01-01

The understanding of the underlying principle that the solar cell consists of a p-n junction is exploited to adapt the basic NPN or PNP Bipolar Junction Transistors (BJT) to serve as solar cells. In this mode the in improvised solar cell have employed just the emitter and the base sections with an intact emitter/base junction as the active PN area. The improvised devices tested screened and sorted are wired up in strings, blocks and modules. The photovoltaic modules realised tested as close replica of solar cells with output voltage following insolation level. Further work need be done on the modules to make them generate usable levels of output voltage and current

Tuning spin transport across two-dimensional organometallic junctions

Science.gov (United States)

Liu, Shuanglong; Wang, Yun-Peng; Li, Xiangguo; Fry, James N.; Cheng, Hai-Ping

2018-01-01

We study via first-principles modeling and simulation two-dimensional spintronic junctions made of metal-organic frameworks consisting of two Mn-phthalocyanine ferromagnetic metal leads and semiconducting Ni-phthalocyanine channels of various lengths. These systems exhibit a large tunneling magnetoresistance ratio; the transmission functions of such junctions can be tuned using gate voltage by three orders of magnitude. We find that the origin of this drastic change lies in the orbital alignment and hybridization between the leads and the center electronic states. With physical insight into the observed on-off phenomenon, we predict a gate-controlled spin current switch based on two-dimensional crystallines and offer general guidelines for designing spin junctions using 2D materials.

NbCN Josephson junctions with AlN barriers

International Nuclear Information System (INIS)

Thomasson, S.L.; Murduck, J.M.; Chan, H.

1991-01-01

This paper reports on niobium carbonitride (NbCN) Josephson circuits which operate over a wider temperature range than either niobium or niobium nitride circuits. Higher operating temperature places NbCN technology more comfortably within the range of closed cycle refrigerators, a key factor in aerospace applications. We have fabricated tunnel junctions from NbCN films with transition temperatures up to 18 Kelvin. High quality NbCN tunnel junction fabrication generally requires low stress films with roughness less than the barrier thickness (∼20 Angstrom). We have developed scanning tunneling microscopy as a tool for measuring and optimizing film smoothness. Junctions formed in situ with AIN tunneling barriers show reproducible I-V characteristics

Measurement of noise in YBCO bi-crystal junctions

International Nuclear Information System (INIS)

Kuznik, J.; Hao, L.; Macfarlane, J.C.; Pegrum, C.M.; Fischer, G.M.; Mygind, J.; Pedersen, N.F.; Beck, A.; Gross, R.

1993-01-01

This paper describes collaborative work between three institutions as part of an ESPRIT programme to fabricate and characterise grain-boundary junctions. Bi-crystal junctions were fabricated at Tuebingen on SrTiO 3 substrates with a 24 misorientation angle and a-b tilt. 200nm of c-axis YBCO was sputter-deposited using a hollow-cathode magnetron, and the films patterned with optical lithography and Ar ion beam etching (3). For test purposes junctions with a range of sizes were made, with widths between 4 and 20μm. These have been characterised for noise properties at 0.3 - 1kHz and 60kHz at Strathclyde, and at 70GHz at Lyngby. (orig.)

Resistance switch employing a simple metal nanogap junction

International Nuclear Information System (INIS)

Naitoh, Yasuhisa; Horikawa, Masayo; Abe, Hidekazu; Shimizu, Tetsuo

2006-01-01

In recent years, several researchers have reported the occurrence of reversible resistance switching effects in simple metal nanogap junctions. A large negative resistance is observed in the I-V characteristics of such a junction when high-bias voltages are applied. This phenomenon is characteristic behaviour on the nanometre scale; it only occurs for gap widths slightly under 13 nm. Furthermore, such a junction exhibits a non-volatile resistance hysteresis when the bias voltage is reduced very rapidly from a high level to around 0 V, and when the bias voltage is reduced slowly. This non-volatile resistance change occurs as a result of changes in the gap width between the metal electrodes, brought about by the applied bias voltage

Quantum Junction Solar Cells

KAUST Repository

Tang, Jiang; Liu, Huan; Zhitomirsky, David; Hoogland, Sjoerd; Wang, Xihua; Furukawa, Melissa; Levina, Larissa; Sargent, Edward H.

2012-01-01

-performing colloidal quantum dot rectifying devices reported to date have relied on a junction between a quantum-tuned absorber and a bulk material (e.g., TiO 2); however, quantum tuning of the absorber then requires complete redesign of the bulk acceptor, compromising

Investigation on Single-Molecule Junctions Based on Current–Voltage Characteristics

Directory of Open Access Journals (Sweden)

Yuji Isshiki

2018-02-01

Full Text Available The relationship between the current through an electronic device and the voltage across its terminals is a current–voltage characteristic (I–V that determine basic device performance. Currently, I–V measurement on a single-molecule scale can be performed using break junction technique, where a single molecule junction can be prepared by trapping a single molecule into a nanogap between metal electrodes. The single-molecule I–Vs provide not only the device performance, but also reflect information on energy dispersion of the electronic state and the electron-molecular vibration coupling in the junction. This mini review focuses on recent representative studies on I–Vs of the single molecule junctions that cover investigation on the single-molecule diode property, the molecular vibration, and the electronic structure as a form of transmission probability, and electronic density of states, including the spin state of the single-molecule junctions. In addition, thermoelectronic measurements based on I–Vs and identification of the charged carriers (i.e., electrons or holes are presented. The analysis in the single-molecule I–Vs provides fundamental and essential information for a better understanding of the single-molecule science, and puts the single molecule junction to more practical use in molecular devices.

Simulations of signal amplification and oscillations using a SNS junction

International Nuclear Information System (INIS)

Luiz, A.M.; Soares, V.; Nicolsky, R.

1998-01-01

A superconducting - normal metal - superconducting junction (SNS junction) may exhibit a low voltage negative differential resistance (LVNDR) effect over part of its current voltage characteristic (CVC). As the LVNDR effect is stable against a bias voltage at this CVC range, it should be possible to combine a SNS junction with conventional electronic circuits to obtain electronic devices such as mixers, amplifiers and oscillators. Making use of this remarkable effect, we show that an amplifier may be feasible by assembling a simple voltage divider made up of a SNS junction in series with a resistor. The amplifier circuit includes an adjustable DC voltage supply (the bias voltage) and an AC signal source with a given voltage. The SNS junction is connected in series with a resistor R. Choosing values of the load resistance R approximately equal to the module of the negative differential resistance (dV/dI), at the bias voltage, we may obtain large gains in this amplifier device. In order to get an oscillator, the SNS junction should be connected to a RLC tank circuit with a bias voltage adjusted in the range of the LVNDR region of its CVC. A power output of the order of one microwatt may be easily obtained. (orig.)

Superconductor-Insulator transition in a single Josephson junction

International Nuclear Information System (INIS)

Sonin, E.B.; PenttilA, J.S.; Parts, O.; Hakonen, P.J.; Paalanen, M.A.

1999-01-01

For ultra small Josephson junctions, when quantum effects become important, dissipative phase transition (DPT) has been predicted. The physical origin of this transition is the suppression of macroscopic quantum tunneling of the phase by tile interaction with dissipative quantum-mechanical environment. Macroscopic quantum tunneling destroys superconductivity of a junction, whereas suppression of tunneling restores superconductivity. Hence, this transition is often called a superconductor-insulator transition (SIT). SIT was predicted for various systems, but its detection in a single Josephson junction is of principal importance since it is the simplest system where this transition is expected, without any risk of being masked by other physical processes, as is possible in more complicated systems like regular or' random Josephson junction arrays. In this Letter we present results of our measurements on R = dV/dI vs. I curves, for a variety of single small isolated Josephson junctions, shunted and un shunted, with different values of capacitance C and normal state tunneling resistance RT. We have detected a crossover. between two types of RI-curves with an essentially different behavior at small currents. On the basis of this crossover, we are able to map out the whole phase diagram for a Josephson junction. The position of the observed phase boundary did not agree with that expected from the original theory. However, the theory revised to take into account a finite accuracy of our voltage measurements (viz., the minimum voltage which we are able to detect), explains well the observed phase diagram. Our important conclusion is that the concept of dissipative phase transition (DPT) and superconductor-insulator transition (SIT) are not completely identical as assumed before. Both are accompanied by the sign change of the thermo resistance, which is traditionally considered as a signature of SIT. Thus any DPT is SIT, but not vice versa. We argue that the real signature

MoRe-based and NbN-based tunnel junctions and their characteristics

International Nuclear Information System (INIS)

Shaternik, V.E.; Noskov, V.L.; Chubatyy, V.V.; Larkin, S.Yu.; Sizontov, V.M.; Miroshnikov, A.M.; Karmazin, A.A.

2007-01-01

Full text: Perspective [1] Josephson Mo-Re alloy-oxide-Pb, Mo-Re alloy-normal metal-oxide-Pb and Mo-Re alloy-normal metal-oxide- normal metal-Mo-Re alloy junctions have been fabricated and investigated. Thin (∼50-100 nm) MoRe superconducting films are deposited on Al 2 O 3 substrates by using a dc magnetron sputtering of MoRe target. Normal metal (Sn, Al) thin films are deposited on the MoRe films surfaces by thermal evaporation of metals in vacuum and oxidized to fabricate junctions oxide barriers. Quasiparticle I-V curves of the fabricated junctions were measured in wide range of voltages. To investigate a transparency spread for the fabricated junctions barriers the computer simulation of the measured quasiparticle I-V curves have been done in framework of the model of multiple Andreev reflections in double-barrier junction interfaces. It's demonstrated the investigated junctions can be described as highly asymmetric double-barrier Josephson junctions with great difference between the two barrier transparencies [2,3]. The result of the comparison of experimental quasiparticle I-V curves and calculated ones is proposed and discussed. Results of computer simulation of quasiparticles I-V curves of NbN-based junctions are presented and discussed. Also I-V curves of the fabricated junctions have been measured under microwave irradiation with 60 GHz frequency , clear Shapiro steps in the measured I-V curves were observed and discussed. (authors)

Reliability of twin-dependent triple junction distributions measured from a section plane

International Nuclear Information System (INIS)

Hardy, Graden B.; Field, David P.

2016-01-01

Numerous studies indicate polycrystalline triple junctions are independent microstructural features with distinct properties from their constituent grain boundaries. Despite the influence of triple junctions on material properties, it is impractical to characterize triple junctions on a large scale using current three-dimensional methods. This work demonstrates the ability to characterize twin-dependent triple junction distributions from a section plane by adopting a grain boundary plane stereology. The technique is validated through simulated distributions and simulated electron back-scatter diffraction (EBSD) data. Measures of validation and convergence are adopted to demonstrate the quantitative reliability of the technique as well as the convergence behavior of twin-dependent triple junction distributions. This technique expands the characterization power of EBSD and prepares the way for characterizing general triple junction distributions from a section plane. - Graphical abstract: The distribution of planes forming a triple junction with a given twin boundary is shown partially in the stereographic projections below from a given projection. The plot on the left shows the ideal/measured distribution and the plot on the right shows the distribution obtained from the stereological method presented here.

Nonlinearity in superconductivity and Josephson junctions

International Nuclear Information System (INIS)

Lazarides, N.

1995-01-01

Within the framework of the Bardeen, Cooper and Schrieffers (BCS) theory, the influence of anisotropy on superconducting states are investigated. Crystal anisotropy exists in un-conventional low temperature superconductors as e.g. U 1-x Th x Be 13 and in high temperature superconductors. Starting from a phenomenological pairing interaction of the electrons or holes, the BCS approach is used to derive a set of coupled nonlinear algebraic equations for the momentum dependent gap parameter. The emphasis is put on bifurcation phenomena between s-, d-wave and mixed s- and d-wave symmetry and the influence on measurable quantities as the electron specific heat, spin susceptibility and Josephson tunnelling. Pitch-fork and perturbed pitch-fork bifurcations have been found separating s- and d-wave superconducting states from mixed s- and d-wave states. The additional superconducting states give rise to jumps in the electron specific heat below the transition temperature. These jumps are rounded in the case of perturbed pitch-fork bifurcations. An experiment to measure the sign of the interlayer interaction using dc SQUIDS is suggested. The Ambegaokar-Baratoff formalism has been used for calculating the quasiparticle current and the two phase coherent tunnelling currents in a Josephson junction made of anisotropic superconductors. It is shown that anisotropy can lead to a reduction in the product of the normal resistance and the critical current. For low voltages across the junction the usual resistively shunted Josephson model can be used. Finally, bunching in long circular Josephson junctions and suppression of chaos in point junctions have been investigated. (au) 113 refs

Breaking into the epithelial apical–junctional complex — news from pathogen hackers

Science.gov (United States)

Vogelmann, Roger; Amieva, Manuel R; Falkow, Stanley; Nelson, W James

2012-01-01

The epithelial apical–junctional complex is a key regulator of cellular functions. In addition, it is an important target for microbial pathogens that manipulate the cell to survive, proliferate and sometimes persist within a host. Out of a myriad of potential molecular targets, some bacterial and viral pathogens have selected a subset of protein targets at the apical–junctional complex of epithelial cells. Studying how microbes use these targets also teaches us about the inherent physiological properties of host molecules in the context of normal junctional structure and function. Thus, we have learned that three recently uncovered components of the apical–junctional complex of the Ig superfamily — junctional adhesion molecule, Nectin and the coxsackievirus and adenovirus receptor — are important regulators of junction structure and function and represent critical targets of microbial virulence gene products. PMID:15037310

Charge transport in junctions between d-wave superconductors

International Nuclear Information System (INIS)

Barash, Y.S.; Galaktionov, A.V.; Zaikin, A.D.

1995-01-01

We develop a microscopic analysis of superconducting and dissipative currents in junctions between superconductors with d-wave symmetry of the order parameter. We study the proximity effect in such superconductors and show that for certain crystal orientations the superconducting order parameter can be essentially suppressed in the vicinity of a nontransparent specularly reflecting boundary. This effect strongly influences the value and the angular dependence of the dc Josephson current j S . At T∼T c it leads to a crossover between j S ∝T c -T and j S ∝(T c -T) 2 respectively for homogeneous and nonhomogeneous distribution of the order parameter in the vicinity of a tunnel junction. We show that at low temperatures the current-phase relation j S (cphi) for superconductor--normal-metal--superconductor junctions and short weak links between d-wave superconductors is essentially nonharmonic and contains a discontinuity at cphi=0. This leads to further interesting features of such systems which can be used for pairing symmetry tests in high-temperature superconductors (HTSC). We also investigated the low-temperature I-V curves of normal-metal--superconductor and superconductor-superconductor tunnel junctions and demonstrated that depending on the junction type and crystal orientation these curves show zero-bias anomalies I∝V 2 , I∝V 2 ln(1/V), and I∝V 3 caused by the gapless behavior of the order parameter in d-wave superconductors. Many of our results agree well with recent experimental findings for HTSC compounds

Towards quantum signatures in a swept-bias Josephson junction

Energy Technology Data Exchange (ETDEWEB)

Losert, Harald; Vogel, Karl; Schleich, Wolfgang P. [Institut fuer Quantenphysik and Center for Integrated Quantum Science and Technology (IQST), Universitaet Ulm, D-89069 Ulm (Germany)

2016-07-01

Josephson junctions are one of the best examples for the observation of macroscopic quantum tunneling. The phase difference in a current-biased Josephson junction behaves like the position of a particle in a tilted washboard potential. The escape of this phase-particle corresponds to the voltage switching of the associated junction. Quantum mechanically, the escape from the washboard potential can be explained as tunneling from the ground state, or an excited state. However, it has been shown, that in the case of periodic driving the experimental data for quantum mechanical key features, e.g. Rabi oscillations or energy level quantization, can be reproduced by a completely classical description. Motivated by this discussion, we investigate a swept-bias Josephson junction in the case of a large critical current. In particular, we contrast the switching current distributions resulting from a quantum mechanical and classical description of the time evolution.

Hyperglycaemia and diabetes impair gap junctional communication among astrocytes.

Science.gov (United States)

Gandhi, Gautam K; Ball, Kelly K; Cruz, Nancy F; Dienel, Gerald A

2010-03-15

Sensory and cognitive impairments have been documented in diabetic humans and animals, but the pathophysiology of diabetes in the central nervous system is poorly understood. Because a high glucose level disrupts gap junctional communication in various cell types and astrocytes are extensively coupled by gap junctions to form large syncytia, the influence of experimental diabetes on gap junction channel-mediated dye transfer was assessed in astrocytes in tissue culture and in brain slices from diabetic rats. Astrocytes grown in 15-25 mmol/l glucose had a slow-onset, poorly reversible decrement in gap junctional communication compared with those grown in 5.5 mmol/l glucose. Astrocytes in brain slices from adult STZ (streptozotocin)-treated rats at 20-24 weeks after the onset of diabetes also exhibited reduced dye transfer. In cultured astrocytes grown in high glucose, increased oxidative stress preceded the decrement in dye transfer by several days, and gap junctional impairment was prevented, but not rescued, after its manifestation by compounds that can block or reduce oxidative stress. In sharp contrast with these findings, chaperone molecules known to facilitate protein folding could prevent and rescue gap junctional impairment, even in the presence of elevated glucose level and oxidative stress. Immunostaining of Cx (connexin) 43 and 30, but not Cx26, was altered by growth in high glucose. Disruption of astrocytic trafficking of metabolites and signalling molecules may alter interactions among astrocytes, neurons and endothelial cells and contribute to changes in brain function in diabetes. Involvement of the microvasculature may contribute to diabetic complications in the brain, the cardiovascular system and other organs.

Construction of tunable peptide nucleic acid junctions.

Science.gov (United States)

Duan, Tanghui; He, Liu; Tokura, Yu; Liu, Xin; Wu, Yuzhou; Shi, Zhengshuang

2018-03-15

We report here the construction of 3-way and 4-way peptide nucleic acid (PNA) junctions as basic structural units for PNA nanostructuring. The incorporation of amino acid residues into PNA chains makes PNA nanostructures with more structural complexity and architectural flexibility possible, as exemplified by building 3-way PNA junctions with tunable nanopores. Given that PNA nanostructures have good thermal and enzymatic stabilities, they are expected to have broad potential applications in biosensing, drug delivery and bioengineering.

Craniovertebral junction stenosis in Lenz-Majewski syndrome

Energy Technology Data Exchange (ETDEWEB)

Mizuguchi, Koichi; Ishigro, Akira [National Center for Child Health and Development, Department of General Pediatrics and Interdisciplinary Medicine, Setagaya-ku, Tokyo (Japan); Miyazaki, Osamu [National Center for Child Health and Development, Department of Radiology, Tokyo (Japan); Nishimura, Gen [Tokyo Metropolitan Children' s Medical Center, Department of Pediatric Imaging, Tokyo (Japan)

2015-09-15

We report a girl with Lenz-Majewski syndrome associated with craniovertebral junction stenosis that led to communicating hydrocephalus and cervical myelopathy. The life-threatening complication was related to progressive craniovertebral hyperostosis that rapidly exacerbated during early childhood. Despite initial success of surgical intervention at 2 years of age, she developed apneic spells and died suddenly at age 5 years. Close monitoring for craniovertebral junction stenosis is essential to reduce morbidity and mortality in children with Lenz-Majewski syndrome. (orig.)

Controlling formation of single-molecule junctions by electrochemical reduction of diazonium terminal groups.

Science.gov (United States)

Hines, Thomas; Díez-Pérez, Ismael; Nakamura, Hisao; Shimazaki, Tomomi; Asai, Yoshihiro; Tao, Nongjian

2013-03-06

We report controlling the formation of single-molecule junctions by means of electrochemically reducing two axialdiazonium terminal groups on a molecule, thereby producing direct Au-C covalent bonds in situ between the molecule and gold electrodes. We report a yield enhancement in molecular junction formation as the electrochemical potential of both junction electrodes approach the reduction potential of the diazonium terminal groups. Step length analysis shows that the molecular junction is significantly more stable, and can be pulled over a longer distance than a comparable junction created with amine anchoring bonds. The stability of the junction is explained by the calculated lower binding energy associated with the direct Au-C bond compared with the Au-N bond.

Negative tunnel magnetoresistance and spin transport in ferromagnetic graphene junctions

International Nuclear Information System (INIS)

Zou Jianfei; Jin Guojun; Ma Yuqiang

2009-01-01

We study the tunnel magnetoresistance (TMR) and spin transport in ferromagnetic graphene junctions composed of ferromagnetic graphene (FG) and normal graphene (NG) layers. It is found that the TMR in the FG/NG/FG junction oscillates from positive to negative values with respect to the chemical potential adjusted by the gate voltage in the barrier region when the Fermi level is low enough. Particularly, the conventionally defined TMR in the FG/FG/FG junction oscillates periodically from a positive to negative value with increasing the barrier height at any Fermi level. The spin polarization of the current through the FG/FG/FG junction also has an oscillating behavior with increasing barrier height, whose oscillating amplitude can be modulated by the exchange splitting in the ferromagnetic graphene.

Negative tunnel magnetoresistance and spin transport in ferromagnetic graphene junctions.

Science.gov (United States)

Zou, Jianfei; Jin, Guojun; Ma, Yu-Qiang

2009-03-25

We study the tunnel magnetoresistance (TMR) and spin transport in ferromagnetic graphene junctions composed of ferromagnetic graphene (FG) and normal graphene (NG) layers. It is found that the TMR in the FG/NG/FG junction oscillates from positive to negative values with respect to the chemical potential adjusted by the gate voltage in the barrier region when the Fermi level is low enough. Particularly, the conventionally defined TMR in the FG/FG/FG junction oscillates periodically from a positive to negative value with increasing the barrier height at any Fermi level. The spin polarization of the current through the FG/FG/FG junction also has an oscillating behavior with increasing barrier height, whose oscillating amplitude can be modulated by the exchange splitting in the ferromagnetic graphene.

Gap junction protein connexin-43 interacts directly with microtubules

NARCIS (Netherlands)

Giepmans, B N; Verlaan, I; Hengeveld, T; Janssen, H; Calafat, J; Falk, M M; Moolenaar, W H

2001-01-01

Gap junctions are specialized cell-cell junctions that mediate intercellular communication. They are composed of connexin proteins, which form transmembrane channels for small molecules [1, 2]. The C-terminal tail of connexin-43 (Cx43), the most widely expressed connexin member, has been implicated

Voltage-dependent conductance states of a single-molecule junction

DEFF Research Database (Denmark)

Wang, Y F; Néel, N; Kröger, J

2012-01-01

Ag–Sn-phthalocyanine–Ag junctions are shown to exhibit three conductance states. While the junctions are conductive at low bias, their impedance drastically increases above a critical bias. Two-level fluctuations occur at intermediate bias. These characteristics may be used to protect a nanoscale...

Salvadoran gangs and extortion. Challenges and priorities related to the extortion phenomenon

Directory of Open Access Journals (Sweden)

Karla Andrade

2015-08-01

Full Text Available During the last few years extortion has garnered a somber relevance for society as a whole, aside from the preponderance it already possessed from law enforcement agents and criminal investigators. The generation of income both in cash and in kind destined for criminal structures, particularly amongst gangs/maras, as well as its implications concerning danger levels and future potential, have made the agencies responsible of public security take a closer look at this crime and ensure there is a full comprehensive assessment made regarding the extortion phenomenon. The above, involved looking into this crime’s different forms of execution, existing enabling factors and the different criminal scenarios it fits into; reviewing how police and prosecutors address these offenses, all operative, investigative and legal implications, as well as the results achieved in the fight against it. Nonetheless, extortionremains a challenge, not only for the institutions involved (Police and the Prosecutor’s Office, but also for the key stakeholders and all those responsible of making strategic decisions for the country.Revista Policía y Seguridad Pública 5(1 2015: 103-148

Construction and maintenance of the Ganges-Brahmaputra-Meghna delta: linking process, morphology, and stratigraphy.

Science.gov (United States)

Wilson, Carol A; Goodbred, Steven L

2015-01-01

We present a review of the processes, morphology, and stratigraphy of the Ganges-Brahmaputra-Meghna delta (GBMD), including insights gained from detailed elevation data. The review shows that the GBMD is best characterized as a composite system, with different regions having morphologic and stratigraphic attributes of an upland fluvial fan delta; a lowland, backwater-reach delta; a downdrift tidal delta plain; and an offshore subaqueous-delta clinoform. These distinct areas of upland and lowland fluvial reaches and tidal dominance vary in time and space, and we distinguish late-Holocene phases of delta construction, maintenance, and decline similar to delta-lobe cycling in other systems. The overall stability of the GBMD landform, relative to many deltas, reflects the efficient, widespread dispersal of sediment by the large monsoon discharge and high-energy tides that affect this region. However, we do identify portions of the delta that are in decline and losing elevation relative to sea level owing to insufficient sediment delivery. These areas, some of which are well inland of the coast, represent those most at risk to the continued effect of sea-level rise.

Superconducting proximity effect in mesoscopic superconductor/normal-metal junctions

CERN Document Server

Takayanagi, H; Toyoda, E

1999-01-01

The superconducting proximity effect is discussed in mesoscopic superconductor/normal-metal junctions. The newly-developed theory shows long-range phase-coherent effect which explaines early experimental results of giant magnetoresistance oscillations in an Andreev interferometer. The theory also shows that the proximity correction to the conductance (PCC) has a reentrant behavior as a function of energy. The reentrant behavior is systematically studied in a gated superconductor-semiconductor junction. A negative PCC is observed in the case of a weak coupling between the normal metal and the external reservoir. Phase coherent ac effect is also observed when rf is irradiated to the junction.

Building memristive and radiation hardness TiO{sub 2}-based junctions

Energy Technology Data Exchange (ETDEWEB)

Ghenzi, N., E-mail: n.ghenzi@gmail.com [Gerencia de Investigación y Aplicaciones, Comisión Nacional de Energía Atómica (Argentina); Rubi, D. [Gerencia de Investigación y Aplicaciones, Comisión Nacional de Energía Atómica (Argentina); ECyT, UNSAM, Martín de Irigoyen 3100, 1650 San Martín, Bs As (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Mangano, E.; Gimenez, G. [Instituto Nacional de Tecnología Industrial (INTI) (Argentina); Lell, J. [Gerencia de Investigación y Aplicaciones, Comisión Nacional de Energía Atómica (Argentina); Zelcer, A. [Gerencia Química, Comisión Nacional de Energía Atómica (Argentina); ECyT, UNSAM, Martín de Irigoyen 3100, 1650 San Martín, Bs As (Argentina); Stoliar, P. [ECyT, UNSAM, Martín de Irigoyen 3100, 1650 San Martín, Bs As (Argentina); IMN, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes (France); and others

2014-01-01

We study micro-scale TiO{sub 2} junctions that are suitable to be used as resistive random-access memory nonvolatile devices with radiation hardness memristive properties. The fabrication and structural and electrical characterization of the junctions are presented. We obtained a retentivity of 10{sup 5} s, an endurance of 10{sup 4} cycles and reliable switching with short electrical pulses (time-width below 10 ns). Additionally, the devices were exposed to 25 MeV oxygen ions. Then, we performed electrical measurements comparing pristine and irradiated devices in order to check the feasibility of using these junctions as memory elements with memristive and radiation hardness properties. - Highlights: • We fabricated radiation hardness memristive metal insulator metal junctions. • We characterized the structural properties of the devices. • We showed the feasibility of the junctions as a non-volatile memory.

Microwave oscillator using arrays of long Josephson junctions

International Nuclear Information System (INIS)

Pagano, S.; Monaco, R.; Costabile, G.

1989-01-01

The authors report on measurements performed on integrated superconducting devices based on arrays of long Josephson tunnel junctions operating in the resonant fluxon oscillation regime (i.e. biased on the Zero Field Steps). The electromagnetic coupling among the junction causes a mutual phase-locking of the fluxon oscillations with a corresponding increase of the emitted power and a decrease of the signal linewidth. This phase-locked state can be controlled by means of an external dc bias current and magnetic field. The effect of the generated microwave signal has been observed on a small Josephson tunnel junction coupled to the array via a microstrip transmission line. The feasibility of the reported devices as local oscillators in an integrated microwave Josephson receiver is discussed

Filtering microfluidic bubble trains at a symmetric junction.

Science.gov (United States)

Parthiban, Pravien; Khan, Saif A

2012-02-07

We report how a nominally symmetric microfluidic junction can be used to sort all bubbles of an incoming train exclusively into one of its arms. The existence of this "filter" regime is unexpected, given that the junction is symmetric. We analyze this behavior by quantifying how bubbles modulate the hydrodynamic resistance in microchannels and show how speeding up a bubble train whilst preserving its spatial periodicity can lead to filtering at a nominally symmetric junction. We further show how such an asymmetric traffic of bubble trains can be triggered in symmetric geometries by identifying conditions wherein the resistance to flow decreases with an increase in the number of bubbles in the microchannel and derive an exact criterion to predict the same.

Creation of stable molecular junctions with a custom-designed scanning tunneling microscope.

Science.gov (United States)

Lee, Woochul; Reddy, Pramod

2011-12-02

The scanning tunneling microscope break junction (STMBJ) technique is a powerful approach for creating single-molecule junctions and studying electrical transport in them. However, junctions created using the STMBJ technique are usually mechanically stable for relatively short times (scanning tunneling microscope that enables the creation of metal-single molecule-metal junctions that are mechanically stable for more than 1 minute at room temperature. This stability is achieved by a design that minimizes thermal drift as well as the effect of environmental perturbations. The utility of this instrument is demonstrated by performing transition voltage spectroscopy-at the single-molecule level-on Au-hexanedithiol-Au, Au-octanedithiol-Au and Au-decanedithiol-Au junctions.

75 FR 76294 - Radio Broadcasting Services: Pacific Junction, IA

Science.gov (United States)

2010-12-08

... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 73 [DA 10-2236; MB Docket No. 10-108] Radio Broadcasting Services: Pacific Junction, IA AGENCY: Federal Communications Commission. ACTION: Final rule. SUMMARY: The staff deletes FM Channel 299C2 at Pacific Junction, Iowa, because the record in this...

P-N semiconductor junctions used as X-ray detectors

International Nuclear Information System (INIS)

Pela, C.A.; Bruco, J.L.; Navas, E.A.; Paula, E. de; Guilardi Neto, T.

1987-01-01

The current response of some comercial P-N semiconductor junctions in function of X-ray incidency, in 40 to 140 KVp band used in diagnosis was characterized. Some junctions were also exposed to radiation of 80 to 250 KVp used in therapy. (C.G.C.) [pt

Effect of quasi-particle injection on retrapping current of Josephson junction

OpenAIRE

Utsunomiya, K.; Yagi, Ryuta

2006-01-01

We report that the energy dissipation of Josephson junction can be controlled by quasi-particle injection. We fabricated two Josephson junctions on the narrow aluminum wire and controlled the energy dissipation of one junction by quasi-particle injection from the other. We observed the retrapping current increased as the quasi-particles were injected. We also studied the heating effect of our measurement.

Multicentre dosimetric comparison of photon-junctioning techniques in head and neck radiotherapy

International Nuclear Information System (INIS)

Kron, T.

2003-01-01

Because many head and neck radiotherapy treatment techniques rely on a junction between X-ray fields, it was the aim of the present study to investigate the use of different junctioning techniques and the affect on the dose across the junction. Techniques in use at nine radiotherapy centres in Australia were investigated using thermoluminescence dosimetry (TLD). The techniques could broadly be divided into two groups: (i) use of the light field to match the fields after moving the patient; and (ii) use of asymmetric collimation to create a single isocentre located in the junction. The mean dose at the junction and its reproducibility was studied in five consecutive treatments in each centre using 25 TLD chips placed throughout the junction in an anthropomorphic phantom. There was a tendency for the mono-isocentric technique to deliver a lower, more accurate mean dose at the junction (Group I: 1.22 Gy (n = 8) vs Group II: 0.96 Gy (n = 5) for 1 Gy planned, some centres contributed to both technique) with greater reproducibility (Group I: 9.6%, Group II: 5.1 % of the mean dose). We conclude that a mono-isocentric treatment technique has the potential to deliver a more accurate and reproducible dose distribution at the field junction of photon beams in head and neck treatment. Copyright (2003) Blackwell Science Pty Ltd

The string-junction picture of multiquark states: an update

CERN Document Server

Rossi, Giancarlo

2016-06-07

We recall and update, both theoretically and phenomenologically, our (nearly) forty-years-old proposal of a string-junction as a necessary complement to the conventional classification of hadrons based just on their quark-antiquark constituents. In that proposal single (though in general metastable) hadronic states are associated with "irreducible" gauge-invariant operators consisting of Wilson lines (visualized as strings of color flux tubes) that may either end on a quark or an antiquark, or annihilate in triplets at a junction $J$ or an anti-junction $\\bar{J}$. For the junction-free sector (ordinary $q\\, \\bar{q}$ mesons and glueballs) the picture is supported by large-$N$ (number of colors) considerations as well as by a lattice strong-coupling expansion. Both imply the famous OZI rule suppressing quark-antiquark annihilation diagrams. For hadrons with $J$ and/or $\\bar{J}$ constituents the same expansions support our proposal, including its generalization of the OZI rule to the suppression of $J-\\bar{J}$ a...

The physical analysis on electrical junction of junctionless FET

Directory of Open Access Journals (Sweden)

Lun-Chun Chen

2017-02-01

Full Text Available We propose the concept of the electrical junction in a junctionless (JL field-effect-transistor (FET to illustrate the transfer characteristics of the JL FET. In this work, nanowire (NW junctionless poly-Si thin-film transistors are used to demonstrate this conception of the electrical junction. Though the dopant and the dosage of the source, of the drain, and of the channel are exactly the same in the JL FET, the transfer characteristics of the JL FET is similar to these of the conventional inversion-mode FET rather than these of a resistor, which is because of the electrical junction at the boundary of the gate and the drain in the JL FET. The electrical junction helps us to understand the JL FET, and also to explain the superior transfer characteristic of the JL FET with the gated raised S/D (Gout structure which reveals low drain-induced-barrier-lowering (DIBL and low breakdown voltage of ion impact ionization.

Molecular electronics: some views on transport junctions and beyond.

Science.gov (United States)

Joachim, Christian; Ratner, Mark A

2005-06-21

The field of molecular electronics comprises a fundamental set of issues concerning the electronic response of molecules as parts of a mesoscopic structure and a technology-facing area of science. We will overview some important aspects of these subfields. The most advanced ideas in the field involve the use of molecules as individual logic or memory units and are broadly based on using the quantum state space of the molecule. Current work in molecular electronics usually addresses molecular junction transport, where the molecule acts as a barrier for incoming electrons: This is the fundamental Landauer idea of "conduction as scattering" generalized to molecular junction structures. Another point of view in terms of superexchange as a guiding mechanism for coherent electron transfer through the molecular bridge is discussed. Molecules generally exhibit relatively strong vibronic coupling. The last section of this overview focuses on vibronic effects, including inelastic electron tunneling spectroscopy, hysteresis in junction charge transport, and negative differential resistance in molecular transport junctions.

Microscopic tunneling theory of long Josephson junctions

DEFF Research Database (Denmark)

Grønbech-Jensen, N.; Hattel, Søren A.; Samuelsen, Mogens Rugholm

1992-01-01

We present a numerical scheme for solving a nonlinear partial integro-differential equation with nonlocal time dependence. The equation describes the dynamics in a long Josephson junction modeled by use of the microscopic theory for tunneling between superconductors. We demonstrate that the detai......We present a numerical scheme for solving a nonlinear partial integro-differential equation with nonlocal time dependence. The equation describes the dynamics in a long Josephson junction modeled by use of the microscopic theory for tunneling between superconductors. We demonstrate...

Mechanically controllable break junctions for molecular electronics.

Science.gov (United States)

Xiang, Dong; Jeong, Hyunhak; Lee, Takhee; Mayer, Dirk

2013-09-20

A mechanically controllable break junction (MCBJ) represents a fundamental technique for the investigation of molecular electronic junctions, especially for the study of the electronic properties of single molecules. With unique advantages, the MCBJ technique has provided substantial insight into charge transport processes in molecules. In this review, the techniques for sample fabrication, operation and the various applications of MCBJs are introduced and the history, challenges and future of MCBJs are discussed. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bar dynamics and channel junctions in scale-experiments of estuaries

Science.gov (United States)

Leuven, J.; Braat, L.; van Dijk, W. M.; Haas, T. D.; Kleinhans, M. G.

2017-12-01

The evolution of channels and bars in estuaries has high socio-economic relevance, with strong implications for navigation, dredging and ecology. However, the spatial and temporal evolution of channels and bars in estuaries is poorly understood. Here, we study feedbacks of bar morphodynamics on widening and narrowing of estuaries. Therefore, we conducted an experiment in a 20 m long and 3 m wide tilting flume (the 'Metronome'), in which we monitored the evolution of a self-formed estuary that developed from an intial straight channel into an irregular planform with multiple channels, braided bars and a meandering ebb channel. At locations where the estuary width is confined, major channel junctions occur, while the zones between the junctions are characterised by high braiding indices, periodically migrating channels and a relatively large estuary width. The junction locations were forced by the in- and outflow locations on the sides of the ebb-tidal delta and at the location where the channel pattern transitions from multiple channels into a single channel. In the middle of the estuary, self-confinement occurred by sedimentation on the sides of the estuary, which caused another major junction. The channel orientation at the junctions steers the morphodynamics of channels and bars immediately landward and seaward, because the orientation of inflow from the ebb-tidal delta and landward river perpetually varies. In natural systems major junction locations are mostly forced by inherited geology or human engineering. However, this study concludes that even without external forcing, the estuary planform will not converge to an ideal shape but will self-confine at major junctions and widens in the adjacent zones, resulting in an irregular planform shape.

T-junction cross-flow mixing with thermally driven density stratification

Energy Technology Data Exchange (ETDEWEB)

Kickhofel, John, E-mail: jkickhofel@gmail.com [Laboratory of Nuclear Energy Systems, ETH Zurich, Sonneggstrasse 3, 8057 Zurich (Switzerland); Prasser, Horst-Michael, E-mail: prasser@lke.mavt.ethz.ch [Laboratory of Nuclear Energy Systems, ETH Zurich, Sonneggstrasse 3, 8057 Zurich (Switzerland); Selvam, P. Karthick, E-mail: karthick.selvam@ike.uni-stuttgart.de [Institute of Nuclear Technology and Energy Systems (IKE), University of Stuttgart, Pfaffenwaldring 31, 70569 Stuttgart (Germany); Laurien, Eckart, E-mail: eckart.laurien@ike.uni-stuttgart.de [Institute of Nuclear Technology and Energy Systems (IKE), University of Stuttgart, Pfaffenwaldring 31, 70569 Stuttgart (Germany); Kulenovic, Rudi, E-mail: rudi.kulenovic@ike.uni-stuttgart.de [Institute of Nuclear Technology and Energy Systems (IKE), University of Stuttgart, Pfaffenwaldring 31, 70569 Stuttgart (Germany)

2016-12-01

Highlights: • Mesh sensor for realistic nuclear thermal hydraulic scenarios is demonstrated. • Flow temperature behavior across a wide range of Richardson numbers measured. • Upstream stratified flow in the T-junction results in a thermal shock scenario. • Large, stable near-wall thermal gradients exist in spite of turbulent flows. - Abstract: As a means of further elucidating turbulence- and stratification-driven thermal fatigue in the vicinity of T-junctions in nuclear power plants, a series of experiments have been conducted at the high temperature high pressure fluid–structure interaction T-junction facility of the University of Stuttgart with novel fluid measurement instrumentation. T-junction mixing with large fluid temperature gradients results in complex flow behavior, the result of density driven effects. Deionized water mixing at temperature differences of up to 232 K at 7 MPa pressure have been investigated in a T-junction with main pipe diameter 71.8 mm and branch line diameter 38.9 mm. The experiments have been performed with fixed flow rates of 0.4 kg/s in the main pipe and 0.1 kg/s in the branch line. A novel electrode-mesh sensor compatible with the DN80 PN100 pipeline upstream and downstream of the T-junction has been utilized as a temperature sensor providing a high density information in the pipe cross-section in both space and time. Additionally, in-flow and in-wall thermocouples quantify the damping of thermal fluctuations by the wall material. The results indicate that large inflow temperature differences lead to strong turbulence damping, and ultimately stable stratification extending both downstream and upstream of the T-junction resulting in large local thermal gradients.

Realization of φ Josephson junctions with a ferromagnetic interlayer

International Nuclear Information System (INIS)

Sickinger, Hanna Sabine

2014-01-01

In this thesis, φ Josephson junctions based on 0-π junctions with a ferromagnetic interlayer are studied. Josephson junctions (JJs) with a ferromagnetic interlayer can have a phase drop of 0 or π in the ground state, depending on the thickness of the ferromagnet (0 JJs or π JJs). Also, 0-π JJs can be realized, where one segment of the junction (if taken separately) is in the 0 state, while the other segment is in the π state. One can use these π Josephson junctions as a device in superconducting circuits, where it provides a constant phase shift, i.e., it acts as a π phase battery. A generalization of a π JJ is a φ JJ, which has the phase ±φ in the ground state. The value of φ can be chosen by design and tuned in the interval 0<φ<π. The φ JJs used in this experiment were fabricated as 0-π JJs with asymmetric current densities in the 0 and π facets. This system can be described by an effective current-phase relation which is tunable by an externally applied magnetic field. The first experimental evidence of such a φ JJ is presented in this thesis. In particular it is demonstrated that (a) a φ JJ has two ground states +φ and -φ, (b) the unknown state can be detected (read out) by measuring the critical current I c (I c+ or I c- ), and (c) a particular state can be prepared by applying a magnetic field or a special bias sweep sequence. These properties of a φ JJ can be utilized, for example, as a memory cell (classical bit). Furthermore, a φ Josephson junction can be used as a deterministic ratchet. This is due to the tunable asymmetry of the potential that can be changed by the external magnetic field. Rectification curves are observed for the overdamped and the underdamped case. Moreover, experimental data of the retrapping process of the phase of a φ Josephson junction depending on the temperature is presented.

Andreev reflexion studies on planar hybrid SNS-junctions based on 122-thin films

Energy Technology Data Exchange (ETDEWEB)

Doering, Sebastian; Schmidt, Stefan; Schmidl, Frank; Tympel, Volker; Seidel, Paul [Friedrich-Schiller-Universitaet Jena, Institut fuer Festkoerperphysik, Helmholtzweg 5, Jena (Germany); Haindl, Silvia; Kurth, Fritz; Iida, Kazumasa; Holzapfel, Bernhard [IFW Dresden, Institut fuer Metallische Werkstoffe, 01069 Dresden (Germany)

2012-07-01

To investigate the properties of iron-based superconductors, we prepared hybrid junctions in thin film technique. Therefore two geometries were prepared, a planar SNS-junction and an edge junction. The base electrode was made of Ba(Fe{sub 0.9}Co{sub 0.1}){sub 2}As{sub 2} thin films, a sputtered gold layer acts as normal barrier for the planar junction and for the counter electrode we used the conventional superconductor lead. We measured the electrical properties of each electrode, as well as the junctions itself. To obtain information about the order parameter symmetry, we show the differential conductance and compare with different variations of an extended BTK-model. We show differences and commonalities between the results of both junction geometries.

The Control of Junction Flows

National Research Council Canada - National Science Library

Smith, Charles

1997-01-01

An experimental study of the effects of spatially-limited (i.e. localized) surface suction on unsteady laminar and turbulent junction flows was performed using hydrogen bubble flow visualization and Particle Image Velocimetry (PIV...

Spin-flip effects on the supercurrent through mesoscopic superconducting junctions

International Nuclear Information System (INIS)

Pan Hui; Lin Tsunghan

2005-01-01

We investigate the spin-flip effects on the Andreev bound states and the supercurrent in a superconductor/quantum-dot/superconductor system, theoretically. The spin-flip scattering in the quantum dot can reverse the supercurrent flowing through the system, which results in a π-junction transition. By controlling the energy level of the quantum dot, the π-junction transition can be caused to occur again. The two mechanisms of the π-junction transitions are interpreted within the picture of Andreev bound states

Electron Transport through Porphyrin Molecular Junctions

Science.gov (United States)

Zhou, Qi

The goal of this work is to study the properties that would affect the electron transport through a porphyrin molecular junction. This work contributes to the field of electron transport in molecular junctions in the following 3 aspects. First of all, by carrying out experiments comparing the conductance of the iron (III) porphyrin (protected) and the free base porphyrin (protected), it is confirmed that the molecular energy level broadening and shifting occurs for porphyrin molecules when coupled with the metal electrodes, and this level broadening and shifting plays an important role in the electron transport through molecular junctions. Secondly, by carrying out an in-situ deprotection of the acetyl-protected free base porphyrin molecules, it is found out that the presence of acetyl groups reduces the conductance. Thirdly, by incorporating the Matrix-assisted laser desorption/ionization (MALDI) spectrum and the in-situ deprotection prior to formation of molecular junctions, it allows a more precise understanding of the molecules involved in the formation of molecular junctions, and therefore allows an accurate analysis of the conductance histogram. The molecules are prepared by self-assembly and the junctions are formed using a Scanning Tunneling Microscopy (STM) molecular break junction technique. The porphyrin molecules are characterized by MALDI in solution before self-assembly to a gold/mica substrate. The self-assembled monolayers (SAMs) of porphyrins on gold are characterized by Ultraviolet-visible (UV-Vis) reflection spectroscopy to confirm that the molecules are attached to the substrate. The SAMs are then characterized by Angle-Resolved X-ray photoelectron spectroscopy (ARXPS) to determine the thickness and the average molecular orientation of the molecular layer. The electron transport is measured by conductance-displacement (G-S) experiments under a given bias (-0.4V). The conductance value of a single molecule is identified by a statistical analysis

Gap junctions and epileptic seizures--two sides of the same coin?

Directory of Open Access Journals (Sweden)

Vladislav Volman

Full Text Available Electrical synapses (gap junctions play a pivotal role in the synchronization of neuronal ensembles which also makes them likely agonists of pathological brain activity. Although large body of experimental data and theoretical considerations indicate that coupling neurons by electrical synapses promotes synchronous activity (and thus is potentially epileptogenic, some recent evidence questions the hypothesis of gap junctions being among purely epileptogenic factors. In particular, an expression of inter-neuronal gap junctions is often found to be higher after the experimentally induced seizures than before. Here we used a computational modeling approach to address the role of neuronal gap junctions in shaping the stability of a network to perturbations that are often associated with the onset of epileptic seizures. We show that under some circumstances, the addition of gap junctions can increase the dynamical stability of a network and thus suppress the collective electrical activity associated with seizures. This implies that the experimentally observed post-seizure additions of gap junctions could serve to prevent further escalations, suggesting furthermore that they are a consequence of an adaptive response of the neuronal network to the pathological activity. However, if the seizures are strong and persistent, our model predicts the existence of a critical tipping point after which additional gap junctions no longer suppress but strongly facilitate the escalation of epileptic seizures. Our results thus reveal a complex role of electrical coupling in relation to epileptiform events. Which dynamic scenario (seizure suppression or seizure escalation is ultimately adopted by the network depends critically on the strength and duration of seizures, in turn emphasizing the importance of temporal and causal aspects when linking gap junctions with epilepsy.

Ligament augmentation for prevention of proximal junctional kyphosis and proximal junctional failure in adult spinal deformity.

Science.gov (United States)

Safaee, Michael M; Deviren, Vedat; Dalle Ore, Cecilia; Scheer, Justin K; Lau, Darryl; Osorio, Joseph A; Nicholls, Fred; Ames, Christopher P

2018-05-01

OBJECTIVE Proximal junctional kyphosis (PJK) is a well-recognized, yet incompletely defined, complication of adult spinal deformity surgery. There is no standardized definition for PJK, but most studies describe PJK as an increase in the proximal junctional angle (PJA) of greater than 10°-20°. Ligament augmentation is a novel strategy for PJK reduction that provides strength to the upper instrumented vertebra (UIV) and adjacent segments while also reducing junctional stress at those levels. METHODS In this study, ligament augmentation was used in a consecutive series of adult spinal deformity patients at a single institution. Patient demographics, including age; sex; indication for surgery; revision surgery; surgical approach; and use of 3-column osteotomies, vertebroplasty, or hook fixation at the UIV, were collected. The PJA was measured preoperatively and at last follow-up using 36-inch radiographs. Data on change in PJA and need for revision surgery were collected. Univariate and multivariate analyses were performed to identify factors associated with change in PJA and proximal junctional failure (PJF), defined as PJK requiring surgical correction. RESULTS A total of 200 consecutive patients were included: 100 patients before implementation of ligament augmentation and 100 patients after implementation of this technique. The mean age of the ligament augmentation cohort was 66 years, and 67% of patients were women. Over half of these cases (51%) were revision surgeries, with 38% involving a combined anterior or lateral and posterior approach. The mean change in PJA was 6° in the ligament augmentation group compared with 14° in the control group (p historical cohort, ligament augmentation is associated with a significant decrease in PJK and PJF. These data support the implementation of ligament augmentation in surgery for adult spinal deformity, particularly in patients with a high risk of developing PJK and PJF.

Nonlocal Cooper pair splitting in a pSn-junction

NARCIS (Netherlands)

Veldhorst, M.; Brinkman, Alexander

2010-01-01

Perfect Cooper pair splitting is proposed, based on crossed Andreev reflection (CAR) in a p-type semiconductor-superconductor-n-type semiconductor (pSn) junction. The ideal splitting is caused by the energy filtering that is enforced by the band structure of the electrodes. The pSn junction is

Gas-liquid flow splitting in T-junction with inclined lateral arm

Science.gov (United States)

Yang, Le-le; Liu, Shuo; Li, Hua; Zhang, Jian; Wu, Ying-xiang; Xu, Jing-yu

2018-02-01

This paper studies the gas-liquid flow splitting in T-junction with inclined lateral arm. The separation mechanism of the T-junction is related to the pressure distribution in the T-junction. It is shown that the separation efficiency strongly depends on the inclination angle, when the angle ranges from 0° to 30°, while not so strongly for angles in the range from 30° to 90° Increasing the number of connecting tubes is helpful for the gas-liquid separation, and under the present test conditions, with four connecting tubes, a good separation performance can be achieved. Accordingly, a multi-tube Y-junction separator with four connecting tubes is designed for the experimental investigation. A good agreement between the simulated and measured data shows that there is an optimal split ratio to achieve the best performance for the multi-tube Y-junction separator.

Thermopower in double planar tunnel junctions with ferromagnetic barriers and nonmagnetic electrodes

Energy Technology Data Exchange (ETDEWEB)

Wilczyński, M., E-mail: wilczyns@if.pw.edu.pl

2017-01-01

The Seebeck effect is investigated in double planar tunnel junctions consisting of nonmagnetic electrodes and the central layer separated by ferromagnetic barriers. Calculations are performed in the linear response theory using the free-electron model. The thermopower is analyzed as a function of the thickness of the central layer, temperature of the junctions and the relative orientation of magnetic moments of the barriers. It has been found that the thermopower can be significantly enhanced in the junction with special central layer thickness due to electron tunneling by resonant states. The thickness of the central layer for which the thermopower is enhanced depends not only on the temperature of the junction but also on the orientation of magnetic moments in the barriers. - Highlights: • Thermopower in the double planar junctions with magnetic barriers is analyzed. • Thermopower can be enhanced due to the resonant tunneling. • Thermopower depends on the magnetic configuration of the junction.

Single-molecule detection of dihydroazulene photo-thermal reaction using break junction technique

Science.gov (United States)

Huang, Cancan; Jevric, Martyn; Borges, Anders; Olsen, Stine T.; Hamill, Joseph M.; Zheng, Jue-Ting; Yang, Yang; Rudnev, Alexander; Baghernejad, Masoud; Broekmann, Peter; Petersen, Anne Ugleholdt; Wandlowski, Thomas; Mikkelsen, Kurt V.; Solomon, Gemma C.; Brøndsted Nielsen, Mogens; Hong, Wenjing

2017-05-01

Charge transport by tunnelling is one of the most ubiquitous elementary processes in nature. Small structural changes in a molecular junction can lead to significant difference in the single-molecule electronic properties, offering a tremendous opportunity to examine a reaction on the single-molecule scale by monitoring the conductance changes. Here, we explore the potential of the single-molecule break junction technique in the detection of photo-thermal reaction processes of a photochromic dihydroazulene/vinylheptafulvene system. Statistical analysis of the break junction experiments provides a quantitative approach for probing the reaction kinetics and reversibility, including the occurrence of isomerization during the reaction. The product ratios observed when switching the system in the junction does not follow those observed in solution studies (both experiment and theory), suggesting that the junction environment was perturbing the process significantly. This study opens the possibility of using nano-structured environments like molecular junctions to tailor product ratios in chemical reactions.

Between Sunda subduction and Himalayan collision: fertility, people and earthquakes on the Ganges-Brahmaputra Delta

Science.gov (United States)

Seeber, L.; Steckler, M. S.; Akhter, S. H.; Goodbred, S. L., Jr.; Gale, J.; McHugh, C. M.; Ferguson, E. K.; Mondal, D. R.; Paola, C.; Reitz, M. D.; Wilson, C.

2014-12-01

A foreland (Ganges) and a suture (Brahmaputra) river, which both drain the Himalaya, have coalesced to form Ganges-Brahmaputra Delta (GBD), the world's largest. The GBD progrades along the continental margin, coupled with an advancing subduction to collision transition, deforming the delta as it grows. A better understanding of this time-transgressive system is urgent now that humans are increasing their forcing of the system and exposure to environmental hazards. Among these, earthquake risk is rapidly growing as people move from rural settings into expanding cities, creating unprecedented exposure. The megathrust 1950 M8.7 earthquake in Assam occurred during the monsoon and released 10x the annual sediment load, causing progradation at the coast and a pulse of river widening that propagated downstream. The 1762 M8.8(?) along the Arakan coast extended into the shelf of the delta where coastal tsunami deposits have been identified recently. These events bracket a segment with no credible historic megathrust earthquakes, but could affect far more people. Geodetic and geologic data along this 300 km boundary facing the GBD show oblique contraction. The subaerial accretionary prism (Burma Ranges) is up to 250 km wide with a blind thrust front that reaches ½ way across the delta. The GPS convergence rate of 14 mm/y is consistent with large displacements and long interseismic times, which can account for lack of historic ruptures, but also the potential for catastrophic events. Active folds and shallow thrust earthquakes point to an additional threat from upper-plate seismicity. Much of the current seismicity is in the lower-plate and reaches as far west as Dhaka; it may pose an immediate threat. The folds, and the uplift and subsidence patterns also influence the courses of the rivers. North of the delta, the Shillong plateau is a huge basement cored anticline bounded by the north-dipping Dauki thrust fault. 7 mm/y of N-S shortening and 5 km of structural relief here

A semiconductor nanowire Josephson junction microwave laser

Science.gov (United States)

Cassidy, Maja; Uilhoorn, Willemijn; Kroll, James; de Jong, Damaz; van Woerkom, David; Nygard, Jesper; Krogstrup, Peter; Kouwenhoven, Leo

We present measurements of microwave lasing from a single Al/InAs/Al nanowire Josephson junction strongly coupled to a high quality factor superconducting cavity. Application of a DC bias voltage to the Josephson junction results in photon emission into the cavity when the bias voltage is equal to a multiple of the cavity frequency. At large voltage biases, the strong non-linearity of the circuit allows for efficient down conversion of high frequency microwave photons down to multiple photons at the fundamental frequency of the cavity. In this regime, the emission linewidth narrows significantly below the bare cavity linewidth to 50%. The junction-cavity coupling and laser emission can be tuned rapidly via an external gate, making it suitable to be integrated into a scalable qubit architecture as a versatile source of coherent microwave radiation. This work has been supported by the Netherlands Organisation for Scientific Research (NWO/OCW), Foundation for Fundamental Research on Matter (FOM), European Research Council (ERC), and Microsoft Corporation Station Q.

Magnetometry with Low-Resistance Proximity Josephson Junction

Science.gov (United States)

Jabdaraghi, R. N.; Peltonen, J. T.; Golubev, D. S.; Pekola, J. P.

2018-06-01

We characterize a niobium-based superconducting quantum interference proximity transistor (Nb-SQUIPT) and its key constituent formed by a Nb-Cu-Nb SNS weak link. The Nb-SQUIPT and SNS devices are fabricated simultaneously in two separate lithography and deposition steps, relying on Ar ion cleaning of the Nb contact surfaces. The quality of the Nb-Cu interface is characterized by measuring the temperature-dependent equilibrium critical supercurrent of the SNS junction. In the Nb-SQUIPT device, we observe a maximum flux-to-current transfer function value of about 55 nA/Φ_0 in the sub-gap regime of bias voltages. This results in suppression of power dissipation down to a few fW. Low-bias operation of the device with a relatively low probe junction resistance decreases the dissipation by up to two orders of magnitude compared to a conventional device based on an Al-Cu-Al SNS junction and an Al tunnel probe (Al-SQUIPT).

A case report of craniovertebral junction intradural extramedullary neurenteric cyst

Directory of Open Access Journals (Sweden)

Rajeshwari S Vhora

2014-01-01

Full Text Available A neurenteric cyst of the craniocervical (CV junction, as a cause of bulbomedullary compression, is very rare. An abnormal communication between the endoderm and neuroectoderm during the third week of embryogenesis may be responsible for its formation. It is a rare spinal condition. The most frequent location is at the lower cervical and higher thoracic spine. Neurenteric cysts of the craniocervical junction are even rarer. We report the case of a CV junction intradural neurenteric cyst. Magnetic Resonance Imaging (MRI of our patient demonstrated an intradural extramedullary process of the craniocervical junction. A surgical posterior approach allowed gross total resection of the lesion. The histopathology of the surgical specimen showed that the cyst wall was made up of fibrocollagen walls lined with a partially ciliated columnar epithelium.

Instabilities in thin tunnel junctions

International Nuclear Information System (INIS)

Konkin, M.K.; Adler, J.G.

1978-01-01

Tunnel junctions prepared for inelastic electron tunneling spectroscopy are often plagued by instabilities in the 0-500-meV range. This paper relates the bias at which the instability occurs to the barrier thickness

Single-electron tunnel junction array

International Nuclear Information System (INIS)

Likharev, K.K.; Bakhvalov, N.S.; Kazacha, G.S.; Serdyukova, S.I.

1989-01-01

The authors have carried out an analysis of statics and dynamics of uniform one-dimensional arrays of ultrasmall tunnel junctions. The correlated single-electron tunneling in the junctions of the array results in its behavior qualitatively similar to that of the Josephson transmission line. In particular, external electric fields applied to the array edges can inject single-electron-charged solitons into the array interior. Shape of such soliton and character of its interactions with other solitons and the array edges are very similar to those of the Josephson vortices (sine-Gordon solitons) in the Josephson transmission line. Under certain conditions, a coherent motion of the soliton train along the array is possible, resulting in generation of narrowband SET oscillations with frequency f/sub s/ = /e where is the dc current flowing along the array

Bandes de « microbes » et insécurité à Abidjan/Gangs of “microbes” and insecurity in Abidjan

Directory of Open Access Journals (Sweden)

Mathieu A. Akadje

2018-03-01

Full Text Available The phenomenon of “microbes” gangs tends to spread throughout the territory of Abidjan district, but especially to increase the number of victims. The objective of this study is to determine the criminal acts perpetrated by the “microbes” and show how this phenomenon is experienced in populations. The methodology is based on desk and field research with the population. The qualitative analysis allowed to highlight crime and insecurity within the population. The results highlighted the fact that the multiple aggressions of “microbes”, both violent and recurrent, led to numerous injuries and even death of the victims. Also, they contributed to the establishment of a feeling of insecurity among the population of Abidjan. Le phénomène des gangs de « microbes » a tendance à s’étendre sur l’ensemble du territoire du district d’Abidjan, mais surtout à accroître le nombre des victimes. L’objectif de cette étude est de déterminer les actes criminels perpétrés par les « microbes » et de montrer comment ce phénomène est vécu au sein des populations. La méthodologie est basée sur une recherche documentaire et de terrain auprès des populations. L’analyse qualitative a permis de mettre en évidence la criminalité et le sentiment d’insécurité au sein de la population. Les résultats ont mis en exergue le fait que les multiples agressions des « microbes », à la fois violentes et récurrentes, ont conduit à de nombreux blessés voire décès des victimes. Aussi, ont-ils concouru à l’instauration d’un sentiment d’insécurité au sein des populations abidjanaises.

Three-dimensional models of conventional and vertical junction laser-photovoltaic energy converters

Science.gov (United States)

Heinbockel, John H.; Walker, Gilbert H.

1988-01-01

Three-dimensional models of both conventional planar junction and vertical junction photovoltaic energy converters have been constructed. The models are a set of linear partial differential equations and take into account many photoconverter design parameters. The model is applied to Si photoconverters; however, the model may be used with other semiconductors. When used with a Nd laser, the conversion efficiency of the Si vertical junction photoconverter is 47 percent, whereas the efficiency for the conventional planar Si photoconverter is only 17 percent. A parametric study of the Si vertical junction photoconverter is then done in order to describe the optimum converter for use with the 1.06-micron Nd laser. The efficiency of this optimized vertical junction converter is 44 percent at 1 kW/sq cm.

Creation of stable molecular junctions with a custom-designed scanning tunneling microscope

International Nuclear Information System (INIS)

Lee, Woochul; Reddy, Pramod

2011-01-01

The scanning tunneling microscope break junction (STMBJ) technique is a powerful approach for creating single-molecule junctions and studying electrical transport in them. However, junctions created using the STMBJ technique are usually mechanically stable for relatively short times (<1 s), impeding detailed studies of their charge transport characteristics. Here, we report a custom-designed scanning tunneling microscope that enables the creation of metal–single molecule–metal junctions that are mechanically stable for more than 1 minute at room temperature. This stability is achieved by a design that minimizes thermal drift as well as the effect of environmental perturbations. The utility of this instrument is demonstrated by performing transition voltage spectroscopy—at the single-molecule level—on Au–hexanedithiol–Au, Au–octanedithiol–Au and Au–decanedithiol–Au junctions.

Superconductive junctions for x-ray spectroscopy

International Nuclear Information System (INIS)

Grand, J.B. le; Bruijn, M.P.; Frericks, M.; Korte, P.A.J. de; Houwman, E.P.; Flokstra, J.

1992-01-01

Biasing of SIS-junctions for the purpose of high energy resolution x-ray detection is complicated by the presence of a DC Josephson current and AC Josephson current resonances, so that a large magnetic field is normally used for the suppression of these Josephson features. A transimpedance amplifier is proposed for biasing and signal amplification at low magnetic field. X-ray spectroscopy detectors for astronomy require a high detection efficiency in the 0.5-10 keV energy band and a reasonable (∼1 cm 2 ) detector area. Calculations on absorber-junctions combinations which might meet these requirements are presented. (author) 9 refs.; 10 figs

Systematic optimization of quantum junction colloidal quantum dot solar cells

KAUST Repository

Liu, Huan; Zhitomirsky, David; Hoogland, Sjoerd; Tang, Jiang; Kramer, Illan J.; Ning, Zhijun; Sargent, Edward H.

2012-01-01

The recently reported quantum junction architecture represents a promising approach to building a rectifying photovoltaic device that employs colloidal quantum dot layers on each side of the p-n junction. Here, we report an optimized quantum

Optical photon detection in Al superconducting tunnel junctions

International Nuclear Information System (INIS)

Brammertz, G.; Peacock, A.; Verhoeve, P.; Martin, D.; Venn, R.

2004-01-01

We report on the successful fabrication of low leakage aluminium superconducting tunnel junctions with very homogeneous and transparent insulating barriers. The junctions were tested in an adiabatic demagnetisation refrigerator with a base temperature of 35 mK. The normal resistance of the junctions is equal to ∼7 μΩ cm 2 with leakage currents in the bias voltage domain as low as 100 fA/μm 2 . Optical single photon counting experiments show a very high responsivity with charge amplification factors in excess of 100. The total resolving power λ/Δλ (including electronic noise) for 500 nm photons is equal to 13 compared to a theoretical tunnel limited value of 34. The current devices are found to be limited spectroscopically by spatial inhomogeneities in the detectors response

Temporal correlations and structural memory effects in break junction measurements

DEFF Research Database (Denmark)

Magyarkuti, A.; Lauritzen, Kasper Primdal; Balogh, Zoltan Imre

2017-01-01

that correlations between the opening and subsequent closing traces may indicate structural memory effects in atomic-sized metallic and molecular junctions. Applying these methods on measured and simulated gold metallic contacts as a test system, we show that the surface diffusion induced flattening of the broken......-molecule junctions, we demonstrate pronounced contact memory effects and recovery of the molecule for junctions breaking before atomic chains are formed. However, if chains are pulled the random relaxation of the chain and molecule after rupture prevents opening-closing correlations....

Intercellular coupling mediated by potassium accumulation in peg-and-socket junctions

DEFF Research Database (Denmark)

Vigmond, Edward J.; Bardakjian, Berj L.; Thuneberg, Lars

2000-01-01

Physiology, peg-and-socket junctions, smooth muscle, boundary element method, coupling, morphology......Physiology, peg-and-socket junctions, smooth muscle, boundary element method, coupling, morphology...

Josephson junction analog and quasiparticle-pair current

DEFF Research Database (Denmark)

Bak, Christen Kjeldahl; Pedersen, Niels Falsig

1973-01-01

A close analogy exists between a Josephson junction and a phase-locked loop. A new type of electrical analog based on this principle is presented. It is shown that the inclusion in this analog of a low-pass filter gives rise to a current of the same form as the Josephson quasiparticle-pair current....... A simple picture of the quasiparticle-pair current, which gives the right dependences, is obtained by assuming a junction cutoff frequency to be at the energy gap. ©1973 American Institute of Physics...

Fabrication and characterization of graphene/molecule/graphene vertical junctions with aryl alkane monolayers

Science.gov (United States)

Jeong, Inho; Song, Hyunwook

2017-11-01

In this study, we fabricated and characterized graphene/molecule/graphene (GMG) vertical junctions with aryl alkane monolayers. The constituent molecules were chemically self-assembled via electrophilic diazonium reactions into a monolayer on the graphene bottom electrode, while the other end physically contacted the graphene top electrode. A full understanding of the transport properties of molecular junctions is a key step in the realization of molecular-scale electronic devices and requires detailed microscopic characterization of the junction's active region. Using a multiprobe approach combining a variety of transport techniques, we elucidated the transport mechanisms and electronic structure of the GMG junctions, including temperature- and length-variable transport measurements, and transition voltage spectroscopy. These results provide criteria to establish a valid molecular junction and to determine the most probable transport characteristics of the GMG junctions.

High-speed carrier-depletion silicon Mach-Zehnder optical modulators with lateral PN junctions

Directory of Open Access Journals (Sweden)

Graham Trevor Reed

2014-12-01

Full Text Available This paper presents new experimental data from a lateral PN junction silicon Mach-Zehnder optical modulator. Efficiencies in the 1.4V.cm to 1.9V.cm range are demonstrated for drive voltages between 0V and 6V. High speed operation up to 52Gbit/s is also presented. The performance of the device which has its PN junction positioned in the centre of the waveguide is then compared to previously reported data from a lateral PN junction device with the junction self-aligned to the edge of the waveguide rib. An improvement in modulation efficiency is demonstrated when the junction is positioned in the centre of the waveguide. Finally we propose schemes for achieving high modulation efficiency whilst retaining self-aligned formation of the PN junction.

Dielectric effect on electric fields in the vicinity of the metal–vacuum–dielectric junction

International Nuclear Information System (INIS)

Chung, M.S.; Mayer, A.; Miskovsky, N.M.; Weiss, B.L.; Cutler, P.H.

2013-01-01

The dielectric effect was theoretically investigated in order to describe the electric field in the vicinity of a junction of a metal, dielectric, and vacuum. The assumption of two-dimensional symmetry of the junction leads to a simple analytic form and to a systematic numerical calculation for the field. The electric field obtained for the triple junction was found to be enhanced or reduced according to a certain criterion determined by the contact angles and dielectric constant. Further numerical calculations of the dielectric effect show that an electric field can experience a larger enhancement or reduction for a quadruple junction than that achieved for the triple junction. It was also found that even though it changes slowly in comparison with the shape effect, the dielectric effect was noticeably large over the entire range of the shape change. - Highlights: ► This work explains how a very strong electric field can be produced due to the dielectric in the vicinity of metal–dielectric contact. ► This work deals with configurations which enhance electric fields using the dielectric effect. The configuration is a type of junction at which metal, vacuum and dielectric meet. ► This work suggests the criterion to determine whether field enhancement occurs or not in the triple junction of metal, vacuum and dielectric. ► This work suggests that a quadruple junction is more effective in enhancing the electric field than a triple junction. The quadruple junction is formed by an additional vacuum portion to the triple junction. ► This work suggests that a triple junction can be a breakthrough candidate for a cold electron source

Single-Molecule Photocurrent at a Metal-Molecule-Semiconductor Junction.

Science.gov (United States)

Vezzoli, Andrea; Brooke, Richard J; Higgins, Simon J; Schwarzacher, Walther; Nichols, Richard J

2017-11-08

We demonstrate here a new concept for a metal-molecule-semiconductor nanodevice employing Au and GaAs contacts that acts as a photodiode. Current-voltage traces for such junctions are recorded using a STM, and the "blinking" or "I(t)" method is used to record electrical behavior at the single-molecule level in the dark and under illumination, with both low and highly doped GaAs samples and with two different types of molecular bridge: nonconjugated pentanedithiol and the more conjugated 1,4-phenylene(dimethanethiol). Junctions with highly doped GaAs show poor rectification in the dark and a low photocurrent, while junctions with low doped GaAs show particularly high rectification ratios in the dark (>10 3 for a 1.5 V bias potential) and a high photocurrent in reverse bias. In low doped GaAs, the greater thickness of the depletion layer not only reduces the reverse bias leakage current, but also increases the volume that contributes to the photocurrent, an effect amplified by the point contact geometry of the junction. Furthermore, since photogenerated holes tunnel to the metal electrode assisted by the HOMO of the molecular bridge, the choice of the latter has a strong influence on both the steady state and transient metal-molecule-semiconductor photodiode response. The control of junction current via photogenerated charge carriers adds new functionality to single-molecule nanodevices.