... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Prevention of gear conflicts. 622.46... Management Measures § 622.46 Prevention of gear conflicts. (a) No person may knowingly place in the Gulf EEZ... zones for shrimp trawling and the use of fixed gear to prevent gear conflicts. Necessary prohibitions or...
... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Prevention of gear conflicts. 654.25... Measures § 654.25 Prevention of gear conflicts. (a) No person may knowingly place in the management area... necessary and appropriate to prevent gear conflicts. Necessary prohibitions or restrictions will be...
The Conflict Prevention and Resolution Center is EPA's primary resource for services and expertise in the areas of consensus-building, collaborative problem solving, alternative dispute resolution, and environmental collaboration and conflict resolution.
This is a study of interstate armed conflict prevention. The concept of conflict, armed conflict and conflict prevention is defined and explained in order to be able to investigate if there is any single institution saddled with the responsibility of preventing interstate armed conflict and also to verify if adequate efforts are been put in this area which is of importance to mankind. The relationship between conflict prevention, conflict management and conflict resolution is also discussed s...
Coy, J. J.; Townsend, D. P.; Zaretsky, E. V.
Gearing technology in its modern form has a history of only 100 years. However, the earliest form of gearing can probably be traced back to fourth century B.C. Greece. Current gear practice and recent advances in the technology are drawn together. The history of gearing is reviewed briefly in the Introduction. Subsequent sections describe types of gearing and their geometry, processing, and manufacture. Both conventional and more recent methods of determining gear stress and deflections are considered. The subjects of life prediction and lubrication are additions to the literature. New and more complete methods of power loss predictions as well as an optimum design of spur gear meshes are described. Conventional and new types of power transmission systems are presented.
de Wilde, J.H.
Conflict prevention has been the nomenclature of a non-military type of security policy, but that is changing. During the Cold War, the OSCE was a forum for conflict prevention at an interstate level. After the Cold War, OSCE conflict prevention turned to domestic affairs, comparable to NGO
Jean de PERSON
Full Text Available Building a trust atmosphere and mobilization in a team or an organizationremains the dream of every manager. This article analyses the internalmechanism of a conflict through life positions diagram in which direction anddominance diagrams appear. The first diagonal, the dominance one, revealsan animal behavior, the latter including both positive aspirations (++ quarter,and also deceptions (-- quarter.Passing over crisis situations requires from managers to outrun, through theirstyle and actions the dominance diagonal and pass to a game with reciprocalgaining (++ quarter, based on trust, that color relations between people andrelease their energy.
Full Text Available The aim of this article is to identify measures that can prevent violent conflict through the maintenance of traditional cultural values that guide conflict avoidance. Moreover, the article focuses on the concepts of conflict prevention and conflict avoidance as applied by the San community of Platfontein. The causes of the inter-communal tensions between the San community members are also examined. A selected conflict situation, that of superstition and witchcraft, is assessed as factors increasing interpersonal conflict in the Platfontein community. This investigation is made to determine if the San preventive measures have an impact in the community, so as to prevent ongoing conflicts from escalating further.
The paper presents the issues of ethnicity, governance, and prevention of conflicts in terms of their political management through the proper exercise of power. Conflict cannot be prevented. It can only be managed. The crucial determining factor is ethnic, gender and class relations in power. The paper traces notion of power ...
Jelaska, Damir T
Understanding how gears are formed and how they interact or 'mesh' with each other is essential when designing equipment that uses gears or gear trains. The way in which gear teeth are formed and how they mesh is determined by their geometry and kinematics, which is the topic of this book. Gears and Gear Drives provides the reader with comprehensive coverage of gears and gear drives. Spur, helical, bevel, worm and planetary gears are all covered, with consideration given to their classification, geometry, kinematics, accuracy control, load capacity and manufacturing. Cylindric
Rodt, Annemarie Peen
The European Union continuously struggles with how to prevent or respond to violent conflicts on its borders. This pressing problem illustrates a European security continuum, which interconnects internal and external security issues and transcends traditional bureaucratic and geographic boundaries...... – severely challenging the Union’s current capabilities as an international security provider. The urgency of improving conflict preventive and crisis management measures is particularly pertinent in Africa, where the numbers affected by conflicts across the continent are staggering. This contribution sets...... out to answer whether – and if so how – EU responses to African conflicts have made a meaningful contribution to preventing (further) conflict. The Union’s efforts in Libya, South Sudan, Democratic Republic of Congo and Central African Republic are critically examined in a comparative case study...
Whitehill, Jennifer M; Webster, Daniel W; Vernick, Jon S
Mediation of potentially violent conflicts is a key component of CeaseFire, an effective gun violence-prevention programme. To describe conflicts mediated by outreach workers (OW) in Baltimore's CeaseFire replication, examine neighbourhood variation, and measure associations between conflict risk factors and successful nonviolent resolution. A cross-sectional study was conducted using records for 158 conflicts mediated between 2007 and 2009. Involvement of youth, gangs, retaliation, weapons and other risk factors were described. Principal component analysis (PCA) was used for data-reduction purposes before the relationship between conflict risk components and mediation success was assessed with multivariate logistic regression. Most conflicts involved 2-3 individuals. Youth, persons with a history of violence, gang members and weapons were commonly present. OWs reported immediate, nonviolent resolution for 65% of mediated conflicts; an additional 23% were at least temporarily resolved without violence. PCA identified four dimensions of conflict risk: the risk-level of individuals involved; whether the incident was related to retaliation; the number of people involved; and shooting likelihood. However, these factors were not related to the OW's ability to resolve the conflict. Neighbourhoods with programme-associated reductions in homicides mediated more gang-related conflicts; neighbourhoods without programme-related homicide reductions encountered more retaliatory conflicts and more weapons.
A. Yu. Kodzhaspirov
Full Text Available Our research aimed at investigating the influence of personality characteristics of parents on specifics of their relationships with children. We considered different ways of family conflicts correction. The study involved 200 families (about 600 people, with one or two children, aged 11 to 14 years. The subject of the study were family conflicts and their impact on child’s behavior. Our hypotheses based on the following assumptions: 1 personal characteristics of parents determine the style of family relationships and characteristics of educational influences, 2 inadequate educational impact of parents causes family conflict, so prevention and education for parents on family relationships will reduce the negative impact of conflict on the personal development of children. Relevance of the study concerns the need to increase attention to modern family by professional psychologists for psychological prevention of family conflict and for parental education.
...; Preventing Personal Conflicts of Interest for Contractor Employees Performing Acquisition Functions AGENCY... approve a new information collection requirement regarding Preventing Personal Conflicts of Interest for... Conflicts of Interest for Contractor Employees Performing Acquisition Functions by any of the following...
Full Text Available Amid unprecedented growth in access to information communication technologies (ICTs, particularly in the developing world, how can international actors, governments, and civil society organizations leverage ICTs and the data they generate to more effectively prevent violence and conflict? New research shows that there is huge potential for innovative technologies to inform conflict prevention efforts, particularly when technology is used to help information flow horizontally between citizens and when it is integrated into existing civil society initiatives.1 However, new technologies are not a panacea for preventing and reducing violence and conflict. In fact, failure to consider the possible knock-on effects of applying a specific technology can lead to fatal outcomes in violent settings. In addition, employing new technologies for conflict prevention can produce very different results depending on the context in which they are applied and whether or not those using the technology take that context into account. This is particularly true in light of the dramatic changes underway in the landscapes of violence and conflict on a global level. As such, instead of focusing on supply-driven technical fixes, those undertaking prevention initiatives should let the context inform what kind of technology is needed and what kind of approach will work best.
FLETCHER, Bobbie; EMADI-COFFIN, Barbara; HETHERINGTON, Janet
This paper examines issues of conflict in schools by using a systems approach based on the Hackman and Morris (1975) Input-Process-Output Model of group performance and Granovetter’s multiple level perspective on macro, meso and micro group levels (1973). This analysis informs the understanding of a school as a community in order to further develop the diversity management programme for the @MINDSET Erasmus+ project. The @MINDSET Conflict Prevention Programme is based on the extensive work of...
Jacobsen, Katja Lindskov; Engell, Troels Gauslå
Contemporary conflict prevention depends on information gathering and knowledge production about developments within the borders of a state, whose internal affairs have been deemed precarious by external actors. The international community, especially the United Nations (UN), calls this early...... conflict prevention as an interventionary practice. Through an analysis of the international community's preventive diplomacy vis-à-vis Burundi (2015–2016) we highlight three unintended power effects: privileging the UN's knowledge production created resistance to international involvement from...... warning and early action. However, for governments whose affairs are considered in need of monitoring, preventive endeavours—and the knowledge production they entail—can be seen as ‘early aggression’. In this article, we argue that seeing knowledge production as having power effects reveals contemporary...
Jensen, Lars H. Ehrensvärd
The fifth brief in the series about special operations highlights the possible strategic role of special operations in connection with Denmark's revitalized vision of integration of the state's instruments to create security through preventive stabilization efforts. The brief offers suggestion...... on tangible operationalization of this vision and provides knowledge on how special operations can be an attractive instrument in comprehensive conflict prevention, including how the special characteristics of special operations make them suitable for supporting the non-military instruments....
Full Text Available The author states that the conflicts in the Mediterranean are put down to interrelated factors –frontier disputes, ethnic-cultural rivalries, low-intensity violence– that make them appear to be “intractable conflicts”, specific to the area, and to which it cannot be automatically applied the model of conflict prevention and management that marked East-West relations during the Cold War. But the author’s analysis goes farther: Biad argues that the initiatives of conflict prevention and management have not done well because of the inadequate definition of objectives (Euro-Arab Dialogue, CSCM,Mediterranean Forum, as well as for the discrimination against some of the southern members and the lack of clearly identified principles and rules for a security dialogue (WEU, NATO, and the OSCE. The Barcelona Process appears to offer a much broader framework as it does underline the need for common action in the prevention of conflicts based on the principles of transparency and sufficiency. Nevertheless, after an analysis of both which focuses on the military dimension of security, the author reminds us that the Barcelona Declaration does not include institutional mechanisms for the application of these principles.
Miller, Robin Lin; Reed, Sarah J; Francisco, Vincent T; Ellen, Jonathan M
Over the prior decade, structural change efforts have become an important component of community-based HIV prevention initiatives. However, these efforts may not succeed when structural change initiatives encounter political resistance or invoke conflicting values, which may be likely when changes are intended to benefit a stigmatized population. The current study sought to examine the impact of target population stigma on the ability of 13 community coalitions to achieve structural change objectives. Results indicated that coalitions working on behalf of highly stigmatized populations had to abandon objectives more often than did coalitions working for less stigmatized populations because of external opposition to coalition objectives and resultant internal conflict over goals. Those coalitions that were most successful in meeting external challenges used opposition and conflict as transformative occasions by targeting conflicts directly and attempting to neutralize oppositional groups or turn them into strategic allies; less successful coalitions working on behalf of stigmatized groups struggled to determine an appropriate response to opposition. The role of conflict transformation as a success strategy for working on behalf of stigmatized groups is discussed.
Full Text Available The media neither start wars, nor can they end them. Communicating media can however have an increasingly positive influence on processes of social communication and societal change. The influence of the media is always multi-causal and long-lasting. In terms of crisis prevention and the treatment of conflicts, media influence requires institutional backing in the form of a controversial public presence, the opportunity for variety and pluralism, media rights as a condition of the rule of law and journalistic ethics codices as a regulating factor for responsible activities on an individual level. When dealing with projects to do with media work on crisis prevention and the treatment of conflicts, the following problems and dilemmas must be recognized: (1 the relationship between violence and cultural autonomy, (2 the relationship between inside and outside, (3 the relationship between social learning and technological intervention, (4 the relationship between NGOs and the state and government and (5 the relationship between getting involved and staying clear. As part of what was known as development communication, the discussions in the 1970s and 1980s provide a good starting point for new tasks. The old approach of social work through media should be revitalized and thought through anew along the lines of the prevention of violence by media. New forms of media should be placed alongside radio and video as suitable for the prevention of violence. In order to be successful, but also so as to bring to the forefront a necessary new political moral stance in development cooperation, it is recommended that a new social network with interested NGOs be founded and have these committed to the following four formal project principles: (1 An orientation towards the needs of the target group has overriding priority. (2 Intensive cooperation and coordination on a local basis with all other projects (especially from other countries and "competing" sponsors
Handschuh, Robert F. (Inventor); Roberts, Gary D. (Inventor)
A hybrid gear consisting of metallic outer rim with gear teeth and metallic hub in combination with a composite lay up between the shaft interface (hub) and gear tooth rim is described. The composite lay-up lightens the gear member while having similar torque carrying capability and it attenuates the impact loading driven noise/vibration that is typical in gear systems. The gear has the same operational capability with respect to shaft speed, torque, and temperature as an all-metallic gear as used in aerospace gear design.
Maddalon, Jeffrey M.; Butler, Ricky W.; Munoz, Cesar A.; Dowek, Gilles
In air traffic management systems, a conflict prevention system examines the traffic and provides ranges of guidance maneuvers that avoid conflicts. This guidance takes the form of ranges of track angles, vertical speeds, or ground speeds. These ranges may be assembled into prevention bands: maneuvers that should not be taken. Unlike conflict resolution systems, which presume that the aircraft already has a conflict, conflict prevention systems show conflicts for all maneuvers. Without conflict prevention information, a pilot might perform a maneuver that causes a near-term conflict. Because near-term conflicts can lead to safety concerns, strong verification of correct operation is required. This paper presents a mathematical framework to analyze the correctness of algorithms that produce conflict prevention information. This paper examines multiple mathematical approaches: iterative, vector algebraic, and trigonometric. The correctness theories are structured first to analyze conflict prevention information for all aircraft. Next, these theories are augmented to consider aircraft which will create a conflict within a given lookahead time. Certain key functions for a candidate algorithm, which satisfy this mathematical basis are presented; however, the proof that a full algorithm using these functions completely satisfies the definition of safety is not provided.
Jul 22, 2011 ... Andrés Serbin: In Latin America, it's key to recognize that conflict is important: we need to change our society and conflict plays a role in this transformation. ... To this end, we have to first of all address the structural causes of why conflicts emerge in the region; second, develop adequate policies regarding ...
Walraven, van K.; Walraven, van K.
This volume is the result of an international symposium on early warning and conflict prevention, held in The Hague in 1996. Two chapters deal with Africa. They investigate the role regional organizations - whether intergovernmental, State or non-State - can play in the prevention of conflicts in
Full Text Available The conflict interaction in the adolescent environment, mainly in the context of intercultural interaction, is considered in the article on the basis of theoretical analysis. The relationship between conflict in adolescence and the overcoming of adolescent crisis is described, as well as the conflict was correlated with other age characteristics. A special emphasis is placed on intergroup conflicts. An additional specificity of conflicts in school classes with mixed cultural composition is discussed. An analysis of the specifics of the conflict interaction in connection with the measurement of cultures by G. Hofstede was carried out (individualism-collectivism, power distance, masculinity-femininity and avoidance of uncertainty. The conclusion about the greater urgency of potential contradictions is being made if there are teenagers belonging to widely differing cultures in the school class. The role of laughter culture as manifestations of antipodes in game form for the prevention and correction of conflicts in a adolescent multicultural environment is shown.
Camerino, Donatella; Sandri, Marco; Sartori, Samantha; Conway, Paul Maurice; Campanini, Paolo; Costa, Giovanni
Shiftwork may be a demanding situation because it raises problems for reconciling work and nonwork activities; as such, this conflict may be mitigated by designing and implementing effective preventative actions at the workplace. There is a paucity of research directly examining the impact of work schedules and preventative measures at work on work-family conflict. Hence, the authors posed the following questions in their study: What is the impact of different work schedules on work-family conflict? Is a preventative culture associated with less work-family conflict? Is work-family conflict associated with specific health and well-being indicators and if so, how does work-family conflict affect well-being as compared with other potential determinants? A subset of 750 nurses ( approximately 10% of total workforce) were randomly selected from a larger sample. Nurses completed the Italian version of the NEXT questionnaire plus newly developed items to create an index on occupational safety and health prevention at work. Data were explored using two data mining techniques, Random Forests and Bayesian Networks, and modeled using hierarchical linear regression models. In all, 664 (88.5% of sample) nurses answered the questionnaire. The authors found that different work schedules had a differential impact on work-family conflict. In addition, effective risk communication between workers and people in charge of safety and health, and participation in preventative activities, quantitative workload, performing tasks not belonging to the nursing profession, and the number of weekends/month spent at work were all strongly associated with work-family conflict. The variable "time schedules" also acted as an effect modifier in the relationship between effective communication and participation in preventative activities and work-family conflict. In addition, quantitative demands played a role as a mediator (30% of total effect) in the relationship between effective communication
A. Yu. Kodzhaspirov
Our research aimed at investigating the influence of personality characteristics of parents on specifics of their relationships with children. We considered different ways of family conflicts correction. The study involved 200 families (about 600 people), with one or two children, aged 11 to 14 years. The subject of the study were family conflicts and their impact on child’s behavior. Our hypotheses based on the following assumptions: 1) personal characteristics of parents determine the style...
Annemarie, Peen Rodt; Tvilling, Johannes; Zartsdahl, Peter Horne
Deliverable 5.1 is a report on EU conflict prevention and peacebuilding in the Horn of Africa and the Western Balkans. It appraises the EU’s Common Security and Defence Policy missions individually within and comparatively across both regions.......Deliverable 5.1 is a report on EU conflict prevention and peacebuilding in the Horn of Africa and the Western Balkans. It appraises the EU’s Common Security and Defence Policy missions individually within and comparatively across both regions....
Davis, J. R
... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Gear Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....
Levin, Tomer T; Parker, Patricia A
While ethical conflicts in the provision of healthcare are common, the current third-party mediator model is limited by a lack of expert ethical mediators, who are often not on site when conflict escalates. In order to improve clinical outcomes in situations such as conflicts at the end of life, we suggest that clinicians-physicians, nurses and social workers-be trained to prevent and de-escalate emerging conflicts. This can be achieved using a mediation model framed by a communication-training approach. A case example is presented and the model is discussed. The implication of this preventative/early intervention model for improving clinical outcomes, in particular end-of life conflict, is considered. Copyright 2015 The Journal of Clinical Ethics. All rights reserved.
Learning from experiences from other parts of the world, it was recommended to incorporate game theory technique in water resources conflicts and cooperation in the African river basins for equitable and fair utilization and management of shared water. Journal of Civil Engineering Research and Practice Vol.1(1) 2004: 51- ...
The increase in the human population has led to dramatic consequences in Sahelian countries, including food shortages, farmland expansion, and conflicts over land and natural resources. Currently, more farmers and herders in south-central Nigertry to use the same land, making it very difficult for herders to find suitable grassland for grazing during the rainy season. Fulbe and Tuareg herders graze livestock on the barren plateau to avoid damaging crops, and the farmers plant millet on land w...
Minossi, José Guilherme
Generally, medico-legal conflicts which occur in surgical and medical practice are a source of worry for both the medical profession and the society as a whole, because on one hand, they could cause high emotional stress for doctors, and on the other hand, patients could be rejected. Once consolidated, defensive medicine increases treatment costs and the doctor-patient relationship could transform into a tragedy. There are many causes for this, including non-treatment factors, such as an unsupported and disorganized health system, lack of participation from society and the doctor in improving this system, the training machine which launches a large number of young unprepared doctors to practice in this noble profession, along with a lack of continuing training, as there are few public or private institutions providing preparation, or further medical training. The related treatment factors are generally, a deficient doctor-patient relationship, poor work condition, power abuse by the doctor, a lack of clear agreement, and poor medical record keeping. These conflicts cannot be solved by simple creating legislation, or by denying the existence of medical error, which occurs at higher frequency than the actual conflicts. It is very important to improve the doctor-patient relationship because an effective fraternal relationship reduces the chance of a judicial demand. The doctor still needs to fully understand his/her conduct obligations and mainly to avoid power abuse. Doctors must also professionally link themselves with politicians who fight for the individual's rights against the system. Society must also understand that health is not just an issue exclusive for doctors, and people must fight to improve living conditions. Society must seriously show its frustration with the increasing disparity between scientific possibilities and actual wellbeing. The training machine needs immediate profound changes to produce professionals with the highest qualifications equipped
Full Text Available The article considers significant characteristics of the phenomenon of corruption resistance of employees of internal affairs agencies as civil servants. The outlined problem of preventing corruption manifestations and conflicts of interests in operational and service activities is characterized by the fact that it exceeds the limits of legal regulation. The possible solution in this case might be the selection of relevant psychological and pedagogical measures of preventing the conflict of interests and the formation of corruption resistance in the personnel of the internal affairs bodies. The article describes the value basis of law enforcement service and personal meanings in the profession.
Gupta, Arun; Holla, Radha; Suri, Shoba
"Conflict of interest", now being commonly cited, is a set of circumstances that creates a risk that professional judgement or actions regarding a primary interest will be unduly influenced by a secondary interest. Conflict of interest situations can be institutional or personal, and can stem from financial or other interests including post-employment opportunities or during public -private partnerships. Conflicts of interest in the creation of public policy, especially health or nutrition related policies such as the vaccine policy, tobacco control, and research related to health, can have negative impact on the lives of millions of people. While the UN Convention Against Corruption, to which India is a signatory, identifies conflict of interest as often being a precursor to corruption, there is no serious action being taken in this direction by the Indian government, in spite of the fact there are instances of serious nature coming to light that affect our peoples lives. If conflict of interest situations are allowed to continue especially in health policy it could be detrimental to millions of people; therefore, it would be in public interest that India enacts a law to prevent conflict of interest in the making of public policies, comprehensive enough to include financial and institutional conflicts of interest.
Salih, Alaaddin M; Ahmed, Jasim M; Mohamed, Jamal F; Alfaki, Musaab M
Given the persistent recurrence of armed conflict, influential actors owe it to the affected communities to take action. The legitimacy of health professionals to mitigate the effects of conflict relates to their ability to save lives and address the physical and mental consequences of armed conflict during which thousands of lives may be lost. Medical professionals have unique and potentially far-reaching skills. These become crucial during wartime and disasters in terms of providing medical services and humanitarian aid. However, they are insufficiently used in one area: involvement in politics as a tool to foster peace. Despite this, Sudanese individuals from medical backgrounds have participated actively in conflict resolution and peace-building processes. In fact, their political actions throughout the last six decades have aimed to prevent conflict at four different levels, which are described by Yusuf et al. in their article on the political involvement of health professionals in prevention. Their stand against President Nimeiri's Sharia laws was primordial prevention of religious conflict at the national level. Their leading role in the second Sudanese Intifada uprising was a key factor in saving the country from civil war, and another example of primary prevention. Sudanese physicians were also involved in secondary prevention by being influentially involved in almost all national peace agreements. Avoiding disputes at the tertiary level represents the weakest link in their repeated efforts. This paper outlines the different roles Sudanese medical personnel have taken in peacemaking. It also critically evaluates them in order to consider new methods of political involvement that suit future challenges.
Hettler, Shannon; Johnston, Linda M.
The authors review the types of experiential peace education programs available to teens in the US and provide a classification guide for educators, parents, other concerned adults and teens who may be interested in developing conflict, peace and/or violence prevention knowledge, skills and attitudes. The authors identify experiential programs in…
Montenegro, Hector Jose
The purpose of this study was to identify and describe the strategies Texas superintendents use to both prevent and resolve conflicts between the school board-superintendent leadership team and to examine the effects of gender, age, ethnicity, level of education, experience in education, tenure as a superintendent, leadership style, and type and…
Atwood, Katharine A.; Kennedy, Stephen B.; Shamblen, Steve; Tegli, Jemee; Garber, Salome; Fahnbulleh, Pearl W.; Korvah, Prince M.; Kolubah, Moses; Mulbah-Kamara, Comfort; Fulton, Shannon
This paper presents findings of a feasibility study to adapt and evaluate the impact of an evidence-based HIV prevention intervention on sexual risk behaviors of in-school 6th grade youth in post-conflict Liberia (n = 812). The study used an attention-matched, group randomized controlled trial. Four matched pairs of elementary/middle schools in…
Mock Nancy B
Full Text Available Abstract In sub-Saharan Africa, HIV/AIDS and violent conflict interact to shape population health and development in dramatic ways. HIV/AIDS can create conditions conducive to conflict. Conflict can affect the epidemiology of HIV/AIDS. Conflict is generally understood to accelerate HIV transmission, but this view is simplistic and disregards complex interrelationships between factors that can inhibit and accelerate the spread of HIV in conflict and post conflict settings, respectively. This paper provides a framework for understanding these factors and discusses their implications for policy formulation and program planning in conflict-affected settings.
Mock, Nancy B; Duale, Sambe; Brown, Lisanne F; Mathys, Ellen; O'maonaigh, Heather C; Abul-Husn, Nina Kl; Elliott, Sterling
In sub-Saharan Africa, HIV/AIDS and violent conflict interact to shape population health and development in dramatic ways. HIV/AIDS can create conditions conducive to conflict. Conflict can affect the epidemiology of HIV/AIDS. Conflict is generally understood to accelerate HIV transmission, but this view is simplistic and disregards complex interrelationships between factors that can inhibit and accelerate the spread of HIV in conflict and post conflict settings, respectively. This paper provides a framework for understanding these factors and discusses their implications for policy formulation and program planning in conflict-affected settings.
Whitehill, Jennifer M; Webster, Daniel W; Frattaroli, Shannon; Parker, Elizabeth M
Cities are increasingly adopting CeaseFire, an evidence-based public health program that uses specialized outreach workers, called violence interrupters (VIs), to mediate potentially violent conflicts before they lead to a shooting. Prior research has linked conflict mediation with program-related reductions in homicides, but the specific conflict mediation practices used by effective programs to prevent imminent gun violence have not been identified. We conducted case studies of CeaseFire programs in two inner cities using qualitative data from focus groups with 24 VIs and interviews with eight program managers. Study sites were purposively sampled to represent programs with more than 1 year of implementation and evidence of program effectiveness. Staff with more than 6 months of job experience were recruited for participation. Successful mediation efforts were built on trust and respect between VIs and the community, especially high-risk individuals. In conflict mediation, immediate priorities included separating the potential shooter from the intended victim and from peers who may encourage violence, followed by persuading the parties to resolve the conflict peacefully. Tactics for brokering peace included arranging the return of stolen property and emphasizing negative consequences of violence such as jail, death, or increased police attention. Utilizing these approaches, VIs are capable of preventing gun violence and interrupting cycles of retaliation.
Barton, Allen W; Beach, Steven R H; Kogan, Steven M; Stanley, Scott M; Fincham, Frank D; Hurt, Tera R; Brody, Gene H
The present study investigates the trajectory of children's exposure to interparental conflict during adolescence, its effects on adolescents' psychological adjustment, as well as the ability of a family-centered prevention program to alter this trajectory. A total of 331 African American couples with an adolescent or preadolescent child participated in a randomized control trial of the Promoting Strong African American Families program, a newly developed program targeting couple and cocaregiving processes. Using a multi-informant, latent growth curve approach, child exposure to interparental conflict during adolescence was found to be stable over a period of 2 years among families in the control group, but significantly declined among families in the treatment condition. Rates of change were significantly different between intervention and control groups based on parents' report of youth exposure to interparental conflict, but not for child's report. Structural equation models found trajectory parameters of interparental conflict predicted changes in adolescent depressive symptoms, with increasing rates of changes in conflict associated with increases in adolescent internalizing symptoms over the 2-year duration of the study. Finally, a significant indirect effect was identified linking treatment, changes in parents' reports of child exposure to interparental conflict, and adolescent depressive symptoms. The implications for research and intervention are discussed. (c) 2015 APA, all rights reserved).
Sustainable prevention of resource conflicts. Conflict risks for access and use of raw materials (report 1); Rohstoffkonflikte nachhaltig vermeiden. Konfliktrisiken bei Zugang und Nutzung von Rohstoffen (Teilbericht 1)
Taenzler, Dennis; Westerkamp, Meike [Adelphi Research, Berlin (Germany); Supersberger, Nikolaus; Ritthoff, Michael; Bleischwitz, Raimund [Wuppertal Institut fuer Klima, Umwelt, Energie GmbH, Wuppertal (Germany)
Inequalities of resources ownership and the consequences of the exploitation of non-renewable resources have always caused violent conflicts of varying intensity. The resulting interdependence between conflicts on the one hand and resources on the other hand - discussed here under the term of conflict-resources nexus - is complex and requires a detailed theoretical and conceptional assessment. The risks of conflict vary as a function of the constellations of actors and the existing political, economic and social boundary conditions. These risks are often globally linked and reflect the flow of resources between consumer countries, transit countries, and producer countries. Conflicts in producer countries may endanger the supply of raw materials to consumer countries. Whether the raw material is an energetic resource like natural gas, petroleum, or coal, or a non-energetic resource like coltane or copper: There are many who demand that Germany should adapt to stronger competition and shorter supply and should also be aware of the possibility of conflicts about raw materials. This part-report of the project 'Sustainable Prevention of Resource Conflicts' presents important theoretical and conceptional considerations on the risk of conflict in the raw materials sector. On this basis, further reports will present case studies, scenarios, and preventive strategies. (orig./RHM)
Camerino, Donatella; Sandri, Marco; Sartori, Samantha
of the NEXT questionnaire plus newly developed items to create an index on occupational safety and health prevention at work. Data were explored using two data mining techniques, Random Forests and Bayesian Networks, and modeled using hierarchical linear regression models. In all, 664 (88.5% of sample) nurses...... answered the questionnaire. The authors found that different work schedules had a differential impact on work-family conflict. In addition, effective risk communication between workers and people in charge of safety and health, and participation in preventative activities, quantitative workload, performing......Shiftwork may be a demanding situation because it raises problems for reconciling work and nonwork activities; as such, this conflict may be mitigated by designing and implementing effective preventative actions at the workplace. There is a paucity of research directly examining the impact of work...
Lisa M. Chauveron
Full Text Available While the demand for youth violence prevention programs increases, the ability of the traditional school day schedule to accommodate violence prevention program time requirements has diminished. School reforms, such as No Child Left Behind, have pressed schools to focus more tightly on academics, often to the exclusion of subjects such as physical education and the arts. Viable violence prevention programs must offer components that supplement classroom curriculum as well as reduce violence and strike a balance between brevity and effectiveness. The Leadership Program’s (TLP universal Violence Prevention Project (VPP meets this call with a conflict resolution model for students in urban schools. The curriculum is based on a conceptual framework derived from prevention science and positive youth development delivered through the vehicle of the arts. Utilizing an engaging hybrid prevention program, this high quality 12 session model melds fidelity and adaptation to yield effective evaluation outcomes.
Giannakakis Ioannis A
Full Text Available Abstract Background Guidelines published in major medical journals are very influential in determining clinical practice. It would be essential to evaluate whether conflicts of interests are disclosed in these publications. We evaluated the reporting of conflicts of interest and the factors that may affect such disclosure in a sample of 191 guidelines on therapeutic and/or preventive measures published in 6 major clinical journals (Annals of Internal Medicine, BMJ, JAMA, Lancet, New England Journal of Medicine, Pediatrics in 1979, 1984, 1989, 1994 and 1999. Results Only 7 guidelines (3.7% mentioned conflicts of interest and all were published in 1999 (17.5% (7/40 of guidelines published in 1999 alone. Reporting of conflicts of interest differed significantly by journal (p=0.026, availability of disclosure policy by the journal (p=0.043, source of funding (p Conclusions Despite some recent improvement, reporting of conflicts of interest in clinical guidelines published in influential journals is largely neglected.
Litvin, Faydor L.; Nava, Alessandro; Fan, Qi; Fuentes, Alfonso
Shapes different from the traditional ones have been proposed for face worm gears and for conical and cylindrical worms that mesh with them. The proposed shapes are based on the concept of generating a face worm gear surface by use of a tilted head cutter instead of by the traditional use of a hob. (As used here, head cutter is also meant to signify, alternatively, a head grinding tool.) The gear-surface-generation equipment would be similar to that used for generation of spiral bevel and hypoid gears. In comparison with the corresponding traditional hob, a tilted head cutter according to the proposal would be larger, could be fabricated with greater precision, and would enable the generation of gear surfaces with greater precision and greater productivity. A face worm gear would be generated (see figure) by use of a tilted head cutter, the blades or grinding surfaces of which would have straight-line profiles. The tilt of the head cutter would prevent interference with teeth adjacent to the groove being cut or ground. A worm to mesh with the face worm gear would be generated by use of a tilted head cutter mounted on the cradle of a generating machine. The blades or grinding surfaces of the head cutter would have a parabolic profile and would deviate from the straight-line profiles of the head cutter for the face worm gear. The shortest distance between the worm and the cradle would follow a parabolic function during the cycle of meshing in the generating process to provide a parabolic function of transmission errors to the gear drive. The small mismatch between the profiles of the face-worm-gear and worm head cutters would make it possible to localize the bearing contact in the worm gear drive. The parabolic function of transmission errors could absorb discontinuous linear functions of transmission errors caused by errors of alignment; this could afford a significant benefit, in that such errors are main sources of noise and vibration in gear drives. The main
Chervenak, Frank A; McCullough, Laurence B
Leaders of academic health centers (AHCs) hold positions that by their very nature have a high potential for ethical conflict. The authors offer an ethical framework for identifying, preventing, and managing conflicts in the leadership of AHCs. This framework is based on and implements both the ethical concept of AHCs as fiduciary organizations and also the legitimate interests of various stakeholders. The authors describe practical steps that can be tools for the preventive-ethics leadership of AHCs that enable leaders to avoid strategic ambiguity and strategic procrastination and replace these with transparency. The ethical framework is illustrated by applying it to an organizational case study. The major contribution of the ethical framework is that it transforms decision making from simply negotiating power struggles to explicitly identifying and making ethical decisions based on the legitimate interests and fiduciary responsibilities of all stakeholders.
Wennmann, Achim; Krause, Keith
This thesis develops a better understanding of the relationship between conflict financing and the recurrence of intra-state armed conflict. It contributes to research on armed conflict by analysing conflict recurrence from the perpective of conflict financing and developing a comprehensive approach to conflict financing and an estimation tool for the cost of armed conflict. In addition, it elaborates a framework for the relationship between conflict financing and conflict dynamics which is a...
Kozlowski, Lynn T.; Kiviniemi, Marc T.; Ram, Pavani Kalluri
Preventing transmission of H1N1 and other infectious diseases can require individuals to change behaviors, but recommendations to change behavior can run counter to other powerful influences. For example, instructions to not shake hands or avoid certain public gatherings can run counter to substantial social pressures to shake hands or be in attendance. These behavioral conflicts are illustrated with an experience of the relative ineffectiveness of voluntary recommendations, which highlights ...
Lafever, A. E. (Inventor)
Epicyclic gear transmissions which transmit output at a gear ratio dependent only upon the input's direction are considered. A transmission housing envelops two epicyclic gear assemblies, and has shafts extending from it. One shaft is attached to a sun gear within the first epicyclic gear assembly. Planet gears are held symmetrically about the sun gear by a planet gear carrier and are in mesh with both the sun gear and a ring gear. Two unidirectional clutches restrict rotation of the first planet gear carrier and ring gear to one direction. A connecting shaft drives a second sun gear at the same speed and direction as the first planet gear carrier while a connecting portion drives a second planet gear carrier at the same speed and direction as the first ring gear. The transmission's output is then transmitted by the second ring gear to the second shaft. Input is transmitted at a higher gear ratio and lower speed for all inputs in the first direction than in the opposite direction.
Davis, J. R
... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Introduction to Gear Technology Chapter 1 Basic Understanding of Gears . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1...
Harris, A O; Jubwe, S; Kennedy, S B; Taylor, C H; Martin, R B; Bee, E M; Perry, O S; Massaquoi, M T; Woods, D V; Barbu, E M
Youths in sub-Saharan Africa (SSA) account for a large burden of the global HIV/STI crises. As such, strategies directed at promoting behavioral modifications would be critical to reducing the prevalence of risky sexual behaviors among high risk adolescents in post-conflict environments. This study describes a condom promotion strategy to prevent HIV/STIs among highly vulnerable urban youth in a post-conflict, resource-constrained environment via the provision of both male and female condoms to nontraditional venues like music and photo shops, ice cream parlors, money exchange centers and beauty salons. Community members in the designated catchment areas volunteered their services and the use of their small businesses to support this endeavor. In this paper, we describe the condom promotion strategy and its implications within the context of a community-based participatory social marketing program to prevent risky sexual behaviors among highly vulnerable urban youth in a post-conflict country. We postulate that this approach may likely increase condom use among urban youth in Monrovia, the capital city of Liberia.
Peltonen, Kirsi; Punamäki, Raija-Leena
Increasing research is available on the preconditions for child mental health and optimal development in traumatic conditions, whereas less is known how to translate the findings into effective interventions to help traumatized children. This literature review analyses the effectiveness of psychosocial preventive interventions and treatments and their theoretical bases among children traumatized in the context of armed conflicts (war, military violence, terrorism and refugee). The first aim is to evaluate the effectiveness of preventive interventions in preventing emotional distress and impairment and promoting optimal emotional-cognitive and social development. The second task is to analyze the nature of the underlying mechanisms for the success of preventive interventions, and the theoretical premises of the choice of intervention techniques, procedures and tools. We found 16 relevant published studies, but an examination of them revealed that only four of them had experimental designs strong enough that they could be included in the meta-analysis. While the subjective reports of the researchers suggested that systematic preventive interventions were effective in decreasing PTSD and depressive symptoms among children traumatized due to armed conflict, the more objective results of the meta-analysis and the weaknesses in designs uncovered during the meta-analysis undermine such a conclusion. Additionally, a majority of the reported preventive interventions focused only on children's biased cognitive processes and negative emotions, while only a few aimed at influencing multiple domains of child development and improving developmental functioning on emotional, social and psychophysiological levels. It is concluded that substantial additional work needs to be done in developing effective preventive interventions and treatments for children traumatized by exposure to war and violence. (c) 2009 Wiley-Liss, Inc.
Watson, H J
Modern Gear Production focuses on the processes and methods in gear making. The book first gives information on the history of gear making and types of gears. Topics such as the classification of gears based on the disposition of their shafts; shafts lying in the same plane with axes intersecting; and shafts lying in parallel planes but with axes inclined to one another are then discussed. The text describes gear groups, tooth forms, and gear materials. Heat treatment of steels, casehardening, nitriding, induction hardening, sulfinuzing, and flame hardening are explained. The book takes a look
This thesis examines community engagement as a form of conflict prevention in order to obtain the social license to operate (SLO) in Alberta's oil and gas industry. It does this by answering the question: what are the key elements of the Social License to Operate and how can these elements be applied to community engagement/consultation in a way that prevents conflicts in Alberta's oil and gas industry? The underlying assumption of this thesis is that building good relationships and working collaboratively functions as a form of conflict prevention and that this in turn leads to the SLO. This thesis outlines the key features of both successful community engagement and of the SLO, to provide a guideline for what is needed to obtain the SLO. Data was collected from semi-structured interviews and through a literature review. The data analysis concluded that there are direct parallels between the key elements of effective community engagement and the key elements of the SLO as identified in the interviews. These parallels are: knowing the community, addressing community needs, corporate social responsibility, relationship building, follow through and evidence for what has been done, executive buy-in, excellent communication, and open dialogue, all within a process which is principled (there is trust, understanding, transparency and respect), inclusive, dynamic, flexible, ongoing, and long-term. Moreover, the key elements of effective community engagement and of the SLO identified in the interviews also overlapped with those found in the literature review, with only one exception. The literature review explicitly named early involvement as a key element of both effective community engagement and the SLO, whereas the interview participants only explicitly indicated it as a key factor of community engagement and implied it to be a key element of the SLO.
Ngo-Metzger, Quyen; Moyer, Virginia; Grossman, David; Ebell, Mark; Woo, Meghan; Miller, Therese; Brummer, Tana; Chowdhury, Joya; Kato, Elisabeth; Siu, Albert; Phillips, William; Davidson, Karina; Phipps, Maureen; Bibbins-Domingo, Kirsten
The U.S. Preventive Services Task Force (USPSTF) provides independent, objective, and scientifically rigorous recommendations for clinical preventive services. A primary concern is to avoid even the appearance of members having special interests that might influence their ability to judge evidence and formulate unbiased recommendations. The conflicts of interest policy for the USPSTF is described, as is the formal process by which best practices were incorporated to update the policy. The USPSTF performed a literature review, conducted key informant interviews, and reviewed conflicts of interest policies of ten similar organizations. Important findings included transparency and public accessibility; full disclosure of financial relationships; disclosure of non-financial relationships (that create the potential for bias and compromise a member's objective judgment); disclosure of family members' conflicts of interests; and establishment of appropriate reporting periods. Controversies in best practices include the threshold of financial disclosures, ease of access to conflicts of interest policies and declarations, vague definition of non-financial biases, and request for family members' conflicts of interests (particularly those that are non-financial in nature). The USPSTF conflicts of interest policy includes disclosures for immediate family members, a clear non-financial conflicts of interest definition, long look-back period and application of the policy to prospective members. Conflicts of interest is solicited from all members every 4 months, formally reviewed, adjudicated, and made publicly available. The USPSTF conflicts of interest policy is publicly available as part of the USPSTF Procedure Manual. A continuous improvement process can be applied to conflicts of interest policies to enhance public trust in members of panels, such as the USPSTF, that produce clinical guidelines and recommendations. Copyright © 2018 American Journal of Preventive Medicine
Dooner, David B
Building on the first edition published in 1995 this new edition of Kinematic Geometry of Gearing has been extensively revised and updated with new and original material. This includes the methodology for general tooth forms, radius of torsure', cylinder of osculation, and cylindroid of torsure; the author has also completely reworked the '3 laws of gearing', the first law re-written to better parallel the existing 'Law of Gearing" as pioneered by Leonard Euler, expanded from Euler's original law to encompass non-circular gears and hypoid gears, the 2nd law of gearing describing a unique relat
Durant, R H; Barkin, S; Krowchuk, D P
To evaluate a Social Cognitive Theory-based violence prevention curriculum among sixth-grade students. The evaluation was conducted using a quasi-experimental pretest-posttest control group design. Students were pretested 2 weeks before the intervention started and were posttested 2 weeks after it ended. The study was conducted in four middle schools serving children and adolescents living in or around public housing in a southeastern city. The participants included all sixth-grade students who were predominantly African-American (88.7%), 41% lived in public housing, and 80% lived in homes with an employed head of household. The intervention schools had 292 students, and the control schools 412 students. The Peaceful Conflict Resolution and Violence Prevention Curriculum is a 13-module skills-building curriculum based on Social Cognitive Theory. It taught identification of situations that could result in violence; avoidance, confrontation, problem-solving, and communication skills; conflict resolution skills; the conflict cycle; the dynamics of a fight; and how to express anger without fighting. The primary outcome variable was a five-item scale assessing the frequency of fighting and weapon carrying behaviors (alpha =.72) and a scale measuring intentions to use violence in 11 hypothetical situations (alpha = .81). Levels of exposure to violence and victimization (alpha = .82) and depression (alpha = .86) were also assessed. The data were analyzed with general linear modeling with repeated measures. At pretest, the intervention and control groups did not differ in gender, age, depression, exposure to violence, or any other demographic variable. A group x time interaction effect (p = .029) was found in the use of violence scale. From pretest to posttest there was a decrease in the use of violence by students in the intervention group and an increase in the use of violence in the control group. Most of the changes were accounted for by changes in the frequencies of
Davis, J. R
... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Proper Gear Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Basic Applied Stresses...
Weinberg, Brian (Inventor); Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor)
A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.
Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.
The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input gear and a larger internal tooth output gear. This unique geometry and offset axis permits the compound gear to mesh with the smaller diameter input gear and the larger diameter output gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction gear set consisting of fewer gears and bearings than a conventional planetary gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input gear to 7.50 PD (internal tooth) intermediate gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate gear to a 10.00 PD output gear (0.750 reduction mesh). Note that it is not required that the intermediate gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output gear, power is transmitted through a hollow drive shaft, which, in turn, drives a sprag during which time the main clutch is disengaged.
Etornam Kosi Anku
Full Text Available The source of conflict between Supermarkets and Wet-markets arise from the use of market power and economies of scale by one group against the other. This study explores the tensions that exist between modern retailers and their traditional counterparts as a result of the influx of supermarkets in Ghana. The main objective of the study is to compare attributes related to the control of access to consumers by the Supermarket and the Wet-market. In this study, the dot-survey approach of Rapid Market Assessment Technique was used to elicit information from 438 respondents at the Madina market (wet-market and Melcom (supermarket over a period of two weeks and Wilcoxon-Mann-Whitney (WMW comparison test and descriptive statistics were employed for the analysis. The results revealed that consumers patronise the supermarkets for convenience and the wet-market for freshness of product. Their purchasing decisions were affected by their level of education and product selections of the retailer. The highly educated preferred to shop at the Supermarket instead of the Wet-market; however, over 50% of respondents preferred the wet-market for fresh food products and the supermarket for non-food items. Each retailer receives its fair share of purchases from its loyal customers, therefore the revolution arising from the supermarket influx in Ghana has not yet resulted into conflict between supermarkets and their traditional counterparts, though it is inevitable if nothing is done to prevent it from happening. To avoid the conflict, it is recommended that policies should be instituted to (i improve the market infrastructures and shopping environment in the Wet-markets, (ii give tax concession to modern retailers who source products from local farmers and small-scale processors, (iii enable traditional retailers position themselves on the fringe and co-exist with modern retailers and (iv enforce public standards with regards to food safety laws in the traditional
Kirill M. Barskiy
Full Text Available Abstract: Shanghai Cooperation Oprganization is a multi-functional interstate regional organizaton. One of the main priorities in the activities of the SCO is a cooperation in providing regional security and stability in the areas of counteraction against terrorism, separatism, extremism, drug tarfficking, other types of trans-border organized crime and against use of information-communication technologies in destructive purposes. There are all grounds to suppose that in forthcoming years the SCO, especially considering broadening the circle of its permanent state-members, will do some steps in direction of practical application of its latent potential in prevention and settlement of conflicts. Development of the SCO own peacekeeping instruments fully corresponds to the character and scales of security threats and tendencies of their evolution on the modern stage. Such a mechanism in arsenal of the SCO could play deterring role regarding latent local conflicts in its zone of responsibility. Obvious «plus» of involving the SCO in the peacekeeping sphere lays in the fact that its key members China and Russia - both are permamnent members of the UN Security Ciuncil, large powers, possessing serious financial capabilities, military and military-technological resources and rich experience of participation in peacekeeping operations. This is exactly Russia and China who would be able to share main responsibility of organization and financing the SCO peacekeeping operations. Emphasis on promoting settlement of conflicts, peacekeeping and strenhthening of confidence in the military sphere could become one of key vectors of converting the SCO into the regional security community and even become a foundation for the new system of security of Eurasia in the future.
The conflict interaction in the adolescent environment, mainly in the context of intercultural interaction, is considered in the article on the basis of theoretical analysis. The relationship between conflict in adolescence and the overcoming of adolescent crisis is described, as well as the conflict was correlated with other age characteristics. A special emphasis is placed on intergroup conflicts. An additional specificity of conflicts in school classes with mixed cultural composition is di...
The prevention of armed conflicts is stated as the priority policy of various international organizations, among which the EU and the OSCE. Based on the semi-structured interviews with high bureaucrats and civilian experts, who areengaged in conflict prevention policies within the two international organizations, the article compares the development and implementation of EU and OSCE strategies to prevent armed conflicts. With the support of the secondmethod, the analysis of primary and second...
Moe, Jeffrey W. (Inventor); Whitmire, Julia (Inventor); Kwan, Hwa-Wan (Inventor); Abeysinghe, Amal (Inventor)
A landing gear noise attenuator mitigates noise generated by airframe deployable landing gear. The noise attenuator can have a first position when the landing gear is in its deployed or down position, and a second position when the landing gear is in its up or stowed position. The noise attenuator may be an inflatable fairing that does not compromise limited space constraints associated with landing gear retraction and stowage. A truck fairing mounted under a truck beam can have a compliant edge to allow for non-destructive impingement of a deflected fire during certain conditions.
It has become very commonplace to note the shift from interstate to intra-state conflict in the world-civil and ethnic wars whose resolution seems to resist the best efforts of the international community...
... of Personal Conflicts of Interest for Contractor Employees (FAR PCI COMMENT) AGENCY: Department of... the question of whether additional guidance is necessary to address personal conflicts of interest by... to address personal conflicts of interest by contractor employees performing acquisition functions...
Young, Jami F.; Gallop, Robert; Mufson, Laura
This article reports on mother-child conflict as an outcome and moderator of Interpersonal Psychotherapy-Adolescent Skills Training (IPT-AST), a preventive intervention for depression. Forty-one adolescents (average age = 13.37, SD = 1.19) with elevated depression symptoms were randomized to receive IPT-AST or school counseling (SC). Adolescents…
V. A. Lobyzenkova
Full Text Available Currently, it is difficult to imagine the existence of people, organizations, societies without conflicts. By themselves, these differences and contradictions can be a positive factor in the development of relations between people and those groups and organizations to which they are united. However, becoming sharp, they can interfere with the successful collaboration and lead to conflict. As many volume categories, the concept of conflict has many definitions and interpretations. One of them defines conflict as a lack of agreement between two or more parties that may be specific individuals or groups. Others invest in the conflict procedure, activity be suitable, considering the conflict active actions of each party sharing of their goals. A colored strong emotional feelings. Summarizing the different points of view, the authors referred to have conflict as a way to interact in the presence of contradictions and incompatible views, positions and interests, as a confrontation between interconnected, but following their purpose two or more parties. Exploring the theoretical side of the conflict, the article notes that it is a meaningful way to determine the object and subject of the conflict. In this regard reveals the content of the object, the subject of the conflict, the issues concerning the process of conflict management in the sphere of municipal service. Based on the analysis of law enforcement practice considers ways to manage and resolve conflicts, noted their negative influence in the power structures, which reduces credibility and confidence in the institution of public service as a whole by society. To improve the efficiency of state and municipal employees, the authors covered technology and ways of conflict management, methods of their overcoming and solutions.
de Franco, Chiara; Meyer, Christoph O.; Brante, John
embraced the case for conflict prevention in policy documents as well as in the Lisbon Treaty itself, making it a hallmark of its approach to international security and conflict in contrast to conventional foreign policy. Yet, it has fallen significantly short in translating these aspirations...... Representatives to avoid the bottleneck problem; • to lend more financial and intelligence support to regional and local early warning systems/NGOs, particularly those which integrate warning and response under one roof. Our paper also addresses the growing importance of the news media and nongovernmental......-represented in the media or issues the news media tend to overlook....
Cummings, E Mark; Schatz, Julie N
The social problem posed by family conflict to the physical and psychological health and well-being of children, parents, and underlying family relationships is a cause for concern. Inter-parental and parent-child conflict are linked with children's behavioral, emotional, social, academic, and health problems, with children's risk particularly elevated in distressed marriages. Supported by the promise of brief psycho-educational programs (e.g., Halford et al. in Journal of Family Psychology 22:497-505, 2008; Sanders in Journal of Family Psychology 22:506-517, 2008), the present paper presents the development and evaluation of a prevention program for community families with children, concerned with family-wide conflict and relationships, and building on Emotional Security Theory (Davies and Cummings in Psychological Bulletin 116:387-411, 1994). This program uniquely focuses on translating research and theory in this area into brief, engaging programs for community families to improve conflict and emotional security for the sake of the children. Evaluation is based on multi-domain and multi-method assessments of family-wide and child outcomes in the context of a randomized control design. A series of studies are briefly described in the programmatic development of a prevention program for conflict and emotional security for community families, culminating in a program for family-wide conflict and emotional security for families with adolescents. With regard to this ongoing program, evidence is presented at the post-test for improvements in family-wide functioning, consideration of the relative benefits for different groups within the community, and preliminary support for the theoretical bases for program outcomes.
Taenzler, Dennis; Westerkamp, Meike [Adelphi Research, Berlin (Germany); Supersberger, Nikolaus; Ritthoff, Michael; Bleischwitz, Raimund [Wuppertal Institut (Germany)
Raw material conflict occurs in various forms: in the form of supply bottlenecks and crises, violent disputes, or even war; as well as due to the effects of environmental destruction, whereby the sources of people's livelihood are lost. Raw material conflict is a reality in many instances, but in others is merely postulated. On the one hand, the nature, strategic importance and price of raw materials influence potential conflict constellations. On the other hand, much depends on the management and governance of raw material resources and production, material flows, value creation chains and sources of financing, across a variety of levels. Existing research into raw material conflict in the field of oil, gas and valuable minerals reveals the multi-layered complexity of the issue as well as the necessity and possibilities of avoiding such conflict in a sustainable manner over the long term. This research landscape was the starting point for the study by adelphi and the Wuppertal Institute titled ''Sustainable Prevention of Resource Conflicts: Identifying and reducing international conflict risk relating to access to and use of raw materials''. The project has added to existing research and delivered new perspectives in relation to lithium and rare earths - resources which are of special relevance for future energy supply and planning - with a view to developing renewable energy sources and meeting ambitious climate protection goals. This report summarises the results of the research project and sets out recommendations. The project was sponsored by the German Federal Environmental Agency, and was conducted in the period between July 2008 and September 2010. The results are published in a total of eight reports which are briefly summarised here. (orig.)
CHAMPS Peer Leadership, Inc., Scottsdale, AZ.
Conflict and violence on the part of adolescents and pre-adolescents has been a growing problem. Young people will respond to an "anti-gang message" if that message is delivered from their peer group. This manual describes a peer approach to impact young people about productive ways to handle conflict. Older students are trained to operate puppets…
14,21 is0 bsmewe assmen thai shape 1:1 doci. Pkv have sir~gular potims . It is known from linmear algebra that the SYstem Of e4UatkW* (6.3 10) has waqi...rotation O") and vectors of gear eccentricity Ae, = O0’) 0, (i = 1, 2) are zero. To model the meshing of gears with eccentricity, we translate the...Rahman. P.. 1951. "Two Mathematical Models of Spiral Bevel Gears Applied to Lubrication and Fatigue L-ife." Proceedings of the International Sonposiurn
... Measures § 697.23 Restricted gear areas. (a) Resolution of lobster gear conflicts with fisheries managed.... 70°16.1′ W. to 181 39°59.3′ N. 70°14.0′ W. Offshore Boundary Point to Latitude Longitude 69 40°07.9...°59.7′ N. 70°13.05′ W. 181 39°59.3′ N. 70°14.0′ W. to 119 40°02.75′ N. 70°16.1′ W. (c) Restricted Gear...
Rasmussen, Peter Omand; Andersen, Torben Ole; Jørgensen, Frank T.
This paper presents a new permanent-magnet gear based on the cycloid gearing principle. which normally is characterized by an extreme torque density and a very high gearing ratio. An initial design of the proposed magnetic gear was designed, analyzed, and optimized with an analytical model regard...... regarding torque density. The results were promising as compared to other high-performance magnetic-gear designs. A test model was constructed to verify the analytical model.......This paper presents a new permanent-magnet gear based on the cycloid gearing principle. which normally is characterized by an extreme torque density and a very high gearing ratio. An initial design of the proposed magnetic gear was designed, analyzed, and optimized with an analytical model...
Magnetic geared actuators (MGA) are designed to perform highly reliable, robust and precise motion on satellite platforms or aerospace vehicles. The design allows MGA to be used for various tasks in space applications. In contrast to conventional geared drives, the contact and lubrication free force transmitting elements lead to a considerable lifetime and range extension of drive systems. This paper describes the fundamentals of magnetic wobbling gears (MWG) and the deduced inherent characteristics, and compares conventional and magnetic gearing.
FINAL 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Climate Change , Instability and a Full Spectrum Approach to...Department of the Navy. 14. ABSTRACT Climate change is an emerging threat to the national security of the United States. It has the potential to...armed forces already engaged in conflicts around the globe. If climate change is the catalyst of crises to come, Africa Command (AFRICOM) must employ
if it encounters a child “ bride ” being kept by an older man? What if the “ bride ” has escaped and says she had been abducted? 2) What should the...areas of deployment, with specific protection for women and children, including through the continued use of Child Protection and Women Protection...armed conflict, including through the deployment of Child Protection Advisors and Women Protection Advisors, and address the needs of victims of
Liliya Igorevna Romadan
Full Text Available The article addresses the cooperation between the United Nations and regional organizations, in particular the African Union in the sphere of security and settlement of conflicts. Over the last decade the role of the AU and sub regional organizations has dramatically increased. Through its agencies of ensuring peace and security the African Union is making significant contribution to strengthening stability and promotion of democracy and human rights in Africa. In the beginning of the article authors make a review of the level of security on the African continent and stress the sharpest conflict zones. According to researches one of the most turbulent regions on continent in terms of security is the North-East Africa. Continuing quarter-century war in Somalia, conflict relations between Somalia and Ethiopia, the border crises between Ethiopia and Eritrea, which in the late 20th century turned into the war between the two countries, finally, the number of armed clashes in Sudan attracted the special attention to the region of the entire world community. Authors pay the main attention to the cooperation between the United Nations and the African Union in the sphere of settling regional conflicts and holding peacekeeping operations. In the article the main mechanisms and methods that are used by the United Nations and the African Union to hold peacekeeping operations are analyzed in details. The situation in Somalia and efforts of the United Nations and the African Union that are making towards stabilization in this country are also studied. Authors reveal the basic elements and make a review of the mixed multicomponent peacekeeping operation of the United Nations and the African Union in Sudan. In the conclusion authors stress the measures that could strengthen the strategic cooperation between the United Nations and the African union. According to the authors the most important task is to solve problems of financing joint peacekeeping operations
Lisa M. Chauveron
While the demand for youth violence prevention programs increases, the ability of the traditional school day schedule to accommodate violence prevention program time requirements has diminished. School reforms, such as No Child Left Behind, have pressed schools to focus more tightly on academics, often to the exclusion of subjects such as physical education and the arts. Viable violence prevention programs must offer components that supplement classroom curriculum as well as reduce violence...
Pedersen, Niels Leergaard; Jørgensen, Martin Felix
The estimation of gear stiffness is important for determining the load distribution between the gear teeth when two sets of teeth are in contact. Two factors have a major influence on the stiffness; firstly the boundary condition through the gear rim size included in the stiffness calculation...... and secondly the size of the contact. In the FE calculation the true gear tooth root profile is applied. The meshing stiffnesses of gears are highly non-linear, it is however found that the stiffness of an individual tooth can be expressed in a linear form assuming that the contact width is constant. © 2014...... Elsevier Ltd. All rights reserved....
This is the first book to offer a complete presentation of bevel gears. An expert team of authors highlights the areas of application for these machine elements and presents the geometrical features of bevel gears as well as the various gear cutting processes based on gear cutting theory. The aspect of three-dimensional gearing is assessed in detail in terms of flank design, load capacity and noise behavior. A representation of production processes with the required technologies provides a knowledge base on which sound decisions can be based. The authors offer a thorough introduction to the complex world of bevel gears and present the rapid advances of these machine elements in a detailed, comprehensible manner. This book addresses design engineers in mechanical engineering and vehicle manufacturing, as well as producers of bevel gears and students in mechanical engineering.
Luttges D, Carolina; Leyton M, Carolina; Leal F, Ingrid; Troncoso E, Paulina; Molina G, Temístocles
Teenage pregnancy is a psychosocial and multifactorial problem described as a lack of exercise of rights in sexual and reproductive health. There are important aspects in the doctor-patient relationship and confidentiality that directly affect the continuity and quality of care. There are controversies in the laws relating to the provision of contraception and confidentiality, and those that protect the sexual indemnity, especially in adolescents under 14 years. To describe the implications of the legal framework for professional midwives in the care of adolescents younger than 14 years in sexual and reproductive health. In-depth interviews were conducted to 13 female and 2 male midwives working at Primary Health Care Centers in the Metropolitan Region. The attention of adolescents younger than 14 years in sexual and reproductive health involves medical-legal issues for health professionals. All professionals recognize that mandatory reporting sexual activity is a complex situation. All professionals notify pregnancies. In relation to the delivery of contraception, clinical care is problematic since professionals should take shelter from a legal standpoint. The medical-legal context of pregnant women under 14 years of age care generates a context of uncertainty and fear for professionals and becomes a source of conflict and insecurity in the exercise of the profession.
Lim, Teik Chin; Singh, Rajendra
A review of the available literature on gear housing vibration and noise radiation is presented. Analytical and experimental methodologies used for bearing dynamics, housing vibration and noise, mounts and suspensions, and the overall gear and housing system are discussed. Typical design guidelines, as outlined by various investigators, are also included. Results of this review indicate that although many attempts were made to characterize the dynamics of gearbox system components, no comprehensive set of design criteria currently exist. Moreover, the literature contains conflicting reports concerning relevant design guidelines.
Chaiko, Lev I.
In proposed worm-gear transmission, oil pumped at high pressure through meshes between teeth of gear and worm coil. Pressure in oil separates meshing surfaces slightly, and oil reduces friction between surfaces. Conceived for use in drive train between gas-turbine engine and rotor of helicopter. Useful in other applications in which weight critical. Test apparatus simulates and measures some loading conditions of proposed worm gear with hydrostatic engagement.
Jørgensen, Frank Thorleif
the calculation models. The first gear type is the very basic magnetic spur gear, which reminds most of all of the traditional mechanical spur gear, the difference is basically that magnetic teeth is replacing mechanical teeth. A magnetic version of the spur gear with a gearing of 1:4 will be able to reach...
Kampen, L.T.B. van
SWOV carried out a literature review on the subject of car front end design for pedestrian injury prevention. The review is aimed at effectiveness and cost of such a design and at the problem of conflicting requirements. Such requirements are existing safety standards and common design rules on the
... Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants shall be maintained in a safe and suitable condition for service. Reverse lever latch shall be so...
Full Text Available Successful heat treating and carburizing of gear wheels for wind turbine gear boxes requires that plastic deformation in the wheel is minimized. Numerical modeling using the DEFORM software was aimed at exploring the effects of the base, on which the gear wheel rests during heating, on the heating process. Homogeneous heating was assumed. It was found that the base heats up more quickly than the workpiece. It is the consequence of the base's shape and volume. As a result, the base expands and slides against the wheel, predominantly at the first heating stage. Later on, it prevents the gear wheel from expanding, causing plastic deformation in the wheel. The findings were used for designing new heating schedules to minimize these undesirable interactions and to reduce the plastic deformation to a negligible magnitude. In addition, this paper presents an example of a practical use of numerical modeling in the DEFORM software.
Full Text Available Successful heat treating and carburizing of gear wheels for wind turbine gear boxes requires that plastic deformation in the wheel is minimized. Numerical modeling using the DEFORM software was aimed at exploring the effects of the base, on which the gear wheel rests during heating, on the heating process. Homogeneous heating was assumed. It was found that the base heats up more quickly than the workpiece. It is the consequence of the base's shape and volume. As a result, the base expands and slides against the wheel, predominantly at the first heating stage. Later on, it prevents the gear wheel from expanding, causing plastic deformation in the wheel. The findings were used for designing new heating schedules to minimize these undesirable interactions and to reduce the plastic deformation to a negligible magnitude. In addition, this paper presents an example of a practical use of numerical modeling in the DEFORM software.
de Figueiredo, John M
This article examines how symbols and sentiments are exchanged to produce a synthesis of two cultures in the context of prolonged bicultural conflict and interaction, thereby minimizing or preventing sociocultural disintegration and the resulting demoralization. This process will be shown to be anchored on the discovery of certain thematic areas (cultural receptors) in which social roles or cultural mandates are missing, unclear, ambiguous or congruent. The setting of this research is the history of Goa, a former Portuguese state on the western coast of India, where the exchange between the Portuguese and Indian cultures lasted longer than four centuries (1510-1961). Both published and unpublished sources were studied. From 1510, the year of the beginning of the Portuguese rule, until 1540, the local traditions and leadership patterns were respected. This was followed by a period of religious intolerance during which attempts were made to encourage Hindus to convert to Christianity and to wipe out the bicultural interaction. Finally a new era of tolerance and cultural integration started around 1773 and continued until 1961. The bicultural interaction persisted and a hybrid culture developed around cultural receptors. The history of Portuguese Goa is a natural experiment that allows us to examine the role played by cultural receptors in the adaptation to acculturative stress.
Taenzler, Dennis; Westerkamp, Meike [Adelphi Research, Berlin (Germany); Supersberger, Nikolaus; Ritthoff, Michael; Bleischwitz, Raimund [Wuppertal Institut (Germany)
Conflicting constellations and the resulting risk of conflict over raw materials are highly complex. This report investigates approaches of various groups of actors and various fields of politics to minimize this risk, with the intention of identifying and analyzing relevant and innovative approaches and to outline their potential and shortcomings in solving risky constellations. The approaches presented here were selected for their relevance and actuality. This includes, on the one hand, approaches that investigate violent conflicts in the producer countries. On the other hand, approaches are considered that attempt to influence the risk of conflict by governmental or private environmental, climate and resources policies. (orig./RHM)
Muhammad Uzair Azizan
, forest, forest offences, penalties, monitoring, enforcement, overlapping of power Citation: Azizan, M.U., Bing, T.S., Raid, M.M., Mohammad, M.T.S, Hussin, K., Rahman, M.M.G.A., and Nadzri, M.I. (2017. Conflicting Role of Land Office and Forestry Department: A Comparative Discussion Regarding to Forest Offences Prevention in Malaysia. Jurnal Ilmu Lingkungan, 15(1, 11-19, doi:10.14710/jil.15.1.11-19
Rackov Milan; Kuzmanović Siniša; Knežević Ivan; Čavić Maja; Penčić Marko
In the area of universal gear reducers, standard does not prescribe relations between load capacity, gear ratios and axis heights. Therefore, larger load capacity of some gear reducers manufacturers has advantage for lower gear ratio and, vice versa, smaller load capacity of the gearbox achieves higher values of gear ratio. However, there are some manufacturers who produce gear reducers with smaller or larger load capacity for higher or lower gear ratio, within the same axis height. This pape...
Cummings, E. Mark; Schatz, Julie N.
The social problem posed by family conflict to the physical and psychological health and well-being of children, parents, and underlying family relationships is a cause for concern. Inter-parental and parent-child conflict are linked with children's behavioral, emotional, social, academic, and health problems, with children's risk particularly…
Anderson, W. J.
Results of selected NASA research programs on rolling-element and fluid-film bearings, gears, and elastohydrodynamic lubrication are reported. Advances in rolling-element bearing material technology, which have resulted in a significant improvement in fatigue life, and which make possible new applications for rolling bearings, are discussed. Research on whirl-resistant, fluid-film bearings, suitable for very high-speed applications, is discussed. An improved method for predicting gear pitting life is reported. An improved formula for calculating the thickness of elastohydrodynamic films (the existence of which help to define the operating regime of concentrated contact mechanisms such as bearings, gears, and cams) is described.
field staff.20 Episodes of kid - napped or murdered aid workers send a chilling message that they are no longer immune from the very violence they seek...Affairs ( DHA ) Nongovernmental Organizations (NGOs) The delivery of emergency relief is dominated by about 15 to 20 major international NGOs or federations...Weapons Convention DHA Department of Humanitarian Affairs (UN) DPKO Department of Peacekeeping Operations (UN) ECOMOG ECOWAS Monitoring Group
Full Text Available A gear is a machine element designed to transmit force and motion from one mechanical unit to another. The design and function of gears are usually closely associated, since gears are designed for a specific function. Various types of gears have...
... limited to, nets, net strengtheners, ropes, lines, or chafing gear, on the top of the regulated portion of... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Gear restrictions. 648.123 Section 648.123... § 648.123 Gear restrictions. (a) Trawl vessel gear restrictions—(1) Minimum mesh size. No owner or...
After the formal approval by CERN Council in December (January, page 1) of the LHC protonproton collider for CERN's 27- kilometre LEP tunnel, preparations for the new machine change gear. Lyndon Evans becomes LHC Project Leader, and CERN's internal structure will soon be reorganized to take account of the project becoming a definite commitment. On the experimental side, the full Technical Proposals for the big general purpose ATLAS and CMS detectors were aired at a major meeting of the LHC Committee at CERN in January. These Technical Proposals are impressive documents each of some several hundred pages. (Summaries of the detector designs will appear in forthcoming issues of the CERN Courier.) The ALICE heavy ion experiment is not far behind, and plans for other LHC experiments are being developed. Playing an important role in this groundwork has been the Detector Research and Development Committee (DRDC), founded in 1990 to foster detector development for the LHC experimental programme and structured along the lines of a traditional CERN Experiments Committee. Established under the Director Generalship of Carlo Rubbia and initially steered by Research Director Walter Hoogland, the DRDC has done sterling work in blazing a trail for LHC experiments. Acknowledging that the challenge of LHC experimentation needs technological breakthroughs as well as specific detector subsystems, DRDC proposals have covered a wide front, covering readout electronics and computing as well as detector technology. Its first Chairman was Enzo larocci, succeeded in 1993 by Michal Turala. DRDC's role was to evaluate proposals, and make recommendations to CERN's Research Board for approval and resource allocation, not an easy task when the LHC project itself had yet to be formally approved. Over the years, a comprehensive portfolio of detector development has been built up, much of which has either led to specific LHC detector subsystems for traditional detector tasks
Radzevich, Stephen P
The first book of its kind, Theory of Gearing: Kinematics, Geometry, and Synthesis systematically develops a scientific theory of gearing that makes it possible to synthesize novel gears with the desired performance. Written by a leading gearing expert who holds more than 200 patents, it presents a modern methodology for gear design. The proposed theory is based on a key postulate: all the design parameters for an optimal gear pair for a particular application can be derived from (a) a given configuration of the rotation vectors of the driving and driven shafts and (b) the power transmitted by
Jørgensen, Frank Thorleif
This thesis deals with design and development of permanent magnetic gears. The goal of this thesis is to develop knowledge and calculation software for magnetic gears. They use strong NdFeB permanent magnets and a new magnetic gear technology, which will be a serious alternative to classical mechanical gears. The new magnetic gear will have a high torque density1 relationship –high efficiency and are maintenance free. In this project was manufactured two test gears which is tested and verifie...
There are countries in Asia, Europe, the Middle East and even a few such countries in Africa that are using non-renewable resources to drive development and have not experienced conflict. South Africa, Namibia, Botswana, and Zambia are such typical cases in Africa. Instead, the presence of significant minerals in Botswana is associated with economic development and democracy as well as peace. ...
In order to develop more efficient types of gears, further investigation into the theories of engagement is necessary. Up until now most of the research work on the theories of engagement has been carried out separately on different groups, and based on individual types of profiles. This book aims at developing some universal theories, which can not only be used for all types of gears, but can also be utilized in other fields such as sculptured surfaces. The book has four characteristics: the investigations are concentrated on mismatched tooth surfaces; all the problems are dealt with from a
Bukanin, V. A.; Ivanov, A. N.; Zenkov, A. E.; Vologdin, V. V.; Vologdin, V. V., Jr.
Problems and solution of gear induction hardening are described. Main attention is paid to the parameters of heating and cooling systems. ELTA 7.0 program has been used to obtain the required electrical parameters of inductor, power sources, resonant circuits, as well as to choose the quenching media. Comparison of experimental and calculated results of investigation is provided. In order to compare advantages and disadvantages of single- and dual-frequency heating processes, many variants of these technologies were simulated. The predicted structure and hardness of steel gears are obtained by use of the ELTA data base taken into account the Continuous Cooling Transformation diagrams.
Johnston, Janet R.
Reviews available research studies of high-conflict divorce and its effects on children. Factors believed to contribute to high-conflict divorce are explored, and a model of their interrelationships is proposed. Dispute resolution, intervention, and prevention programs are discussed, and implications for social policy are outlined. (SLD)
Mavriplis, Dimitri; Huston, Ronald L.
The use of computer graphics to simulate gear tooth manufacturing procedures is discussed. An analytical basis for the simulation is established for spur gears. The simulation itself, however, is developed not only for spur gears, but for straight bevel gears as well. The applications of the developed procedure extend from the development of finite element models of heretofore intractable geometrical forms, to exploring the fabrication of nonstandard tooth forms.
Ramarao, S.V.S.; Mathai, P.G.; George, V.C.; Kunjipalu, K.K.; Varghese, M.D.; Kuttappan, A.C.
Sharks are mainly harvested with long lines which is less expensive compared to other methods of fishing. Though this is a common gear operated along the coast, the gear in every region has its own peculiarities in construction and rigging. This communication furnishes detailed description of the gear operated in different centres. Suggestions are also offered to improve the gear and methods for enhancing production.
Hu, Chongqing; Smith, Wade A.; Randall, Robert B.; Peng, Zhongxiao
Gear tooth wear is an inevitable phenomenon and has a significant influence on gear dynamic features. Although vibration analysis has been widely used to diagnose localised gear tooth faults, its techniques for gear wear monitoring have not been well-established. This paper aims at developing a vibration indicator to evaluate the effects of wear on gear performance. For this purpose, a gear state vector is extracted from time synchronous averaged gear signals to describe the gear state. This gear state vector consists of the sideband ratios obtained from a number of tooth meshing harmonics and their sidebands. Then, two averaged logarithmic ratios, ALR and mALR, are defined with fixed and moving references, respectively, to provide complementary information for gear wear monitoring. Since a fixed reference is utilised in the definition of ALR, it reflects the cumulated wear effects on the gear state. An increase in the ALR value indicates that the gear state deviates further from its reference condition. With the use of a moving reference, the indicator mALR shows changes in the gear state within short time intervals, making it suitable for wear process monitoring. The efficiency of these vibration indicators is demonstrated using experimental results from two sets of tests, in which the gears experienced different wear processes. In addition to gear wear monitoring, the proposed indicators can be used as general parameters to detect the occurrence of other faults, such as a tooth crack or shaft misalignment, because these faults would also change the gear vibrations.
..., lines, or chafing gear, on the top of the regulated portion of a trawl net; except that, one splitting... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Gear restrictions. 648.104 Section 648.104... Flounder Fisheries § 648.104 Gear restrictions. (a) General. (1) Otter trawlers whose owners are issued a...
From international perspective, parallel importation, especially with respect to drugs, has to do with the exhaustion principle in Article 6 of the TRIPS Agreement and the general exception in Article XX of the GATT 1994. Issues concerning the TRIPS Agreement have been constant topics of discussion. However, parallel importation in relation to the general rules of the GATT 1994 as well as to its exceptions provided in Article XX was not seriously discussed. In the view of the paper, there is a conflict between the provisions in these two agreements. The paper explains such conflict and tries to propose a method of interpretation to resolve the conflict between GATT Article XX and TRIPS Article 6 concerning parallel importation for the purpose of reducing the possible undesirable market segmentation in pharmaceutical sector. The method suggested in the paper is a proper application of good faith principle in the Vienna Convention to interpret GATT Article XX, so that there could be some flexibility for those prohibitions of parallel importation which have positive effect on international trade.
Full Text Available This paper discusses the effects of TiN coating on gear contact fatigue performance through contact fatigue experiment and gear rig test. The results reveal that the deposition on gears with hard coating TiN could provide the subsurface protection and improve the contact fatigue life, and the contact fatigue strength of nitrided+TiN coated 32Cr2MoV is 1557 MPa at survival probability of 99%, 284 MPa higher than that of nitrided 32Cr2MoV. Although TiN coating on the the edge of the meshing zone wore out, there is no obvious pitting at the site and the rest of meshed zone of TiN coated gear keeps well without pittings and wear grooves, which is opposite to nitrided gears with pittings and peeling off. TiN coating is dense and smooth with lower surface roughness, and it wraps up the gear tooth so that the gear surface no longer contacts with lubricant and prevents the cracks initiation, prolonging the contact fatigue life of gears.
Goanta, A. M.; Dumitrache, P.
The current situation in the design of gearings is different from software to software and in some cases requires specialized settings with or without additional costs. There are two ways of generating evolving tooting: one is based on the designer’s solid knowledge of geometry and gearing and the other is based on a series of automation subprograms for 3D modelling of gears. The first method is a general one, applicable to all design software that is based on generating a curve evolving specific to a tooth flank, continued with the construction of the symmetrical flank, the pattern multiplication of circular type around the center of the gear and finally generation of the three-dimensional characteristic of each individual tooth. The second method is much faster and requires only general knowledge about the gear but sufficiently advanced to allow permanent dialogue with the subprogram for generating cone gears. Absolute novelty items are brought about by the new NX design applications that lead to getting gears with curved teeth. In conclusion the paper shows how different variants of bevel gears are generated using various subprograms or performance settings, installed over the SIEMENS NX. An essential component of the paper is highlighting generation capacity of gears and gearing intended for predefined types of gear cutting machines such as those for Gleason and Oerlikon teeth.
Derkyi, M.A.A.; Ros-Tonen, M.A.F.; Kyereh, B.; Dietz, A.J.
Conflicts undermine forest-based livelihoods for the rural poor. Conflict management is key to preventing such conflicts. This article analyzes actor perceptions of forest- and tree-related conflicts and conflict management in Ghana's high forest zone. It also assesses a phased methodology that
Derkyi, M.A.A.; Ros-Tonen, M.A.F.; Kyereh, B.; Dietz, T.
Conflicts undermine forest-based livelihoods for the rural poor. Conflict management is key to preventing such conflicts. This article analyzes actor perceptions of forest- and tree-related conflicts and conflict management in Ghana's high forest zone. It also assesses a phased methodology that
Mcdougal, A. R.; Norman, R. M. (Inventor)
A gear head wrench particularly suited for use in applying torque to bolts without transferring torsional stress to bolt-receiving structures is introduced. The wrench is characterized by a coupling including a socket, for connecting a bolt head with a torque multiplying gear train, provided within a housing having an annulus concentrically related to the socket and adapted to be coupled with a spacer interposed between the bolt head and the juxtaposed surface of the bolt-receiving structure for applying a balancing counter-torque to the spacer as torque is applied to the bolt head whereby the bolt-receiving structure is substantially isolated from torsional stress. As a result of the foregoing, the operator of the wrench is substantially isolated from any forces which may be imposed.
McMahon, James M; Chimenti, Ruth; Trabold, Nicole; Fedor, Theresa; Mittal, Mona; Tortu, Stephanie
Heterosexual transmission of HIV often occurs in the context of intimate sexual partnerships. There is mounting evidence that couple-based HIV prevention interventions may be more effective than individual-based interventions for promoting risk reduction within such relationships. Yet, concerns have been raised about the safety of couple-based prevention approaches, especially with regard to the risk of intimate partner violence against women. Although several international studies have examined the potential for adverse consequences associated with couple-based interventions, with inconsistent results, there is little data from U.S. studies to shed light on this issue. The current study analyzed data from a randomized trial conducted in New York City with 330 heterosexual couples to examine whether participation in couple-based or relationship-focused HIV counseling and testing (HIV-CT) interventions resulted in an increased likelihood of post-intervention breakups, relationship conflicts, or emotional, physical, or sexual abuse, compared with standard individual HIV-CT. Multinomial logistic regression was used to model the odds of experiencing change in partner violence from baseline to follow-up by treatment condition. A high prevalence of partner-perpetrated violence was reported by both male and female partners across treatment conditions, but there was no conclusive evidence of an increase in relationship dissolution or partner violence subsequent to participation in either the couple-based HIV-CT intervention or relationship-focused HIV-CT intervention compared with controls. Qualitative data collected from the same participants support this interpretation. HIV prevention interventions involving persons in primary sexual partnerships should be sensitive to relationship dynamics and the potential for conflict, and take precautions to protect the safety of both male and female participants. © The Author(s) 2015.
In this study, the case properties and diffusion kinetics of GS18NiMoCr36 (GS18), GS22NiMoCr56 (GS22) and GS32NiCrMo6.4 (GS32) gear steels borided in Ekabor-II powder were investigated by conducting a series of experiments at temperatures of 1123, 1173 and 1223 K for 2, 4 and 6 h. The boride layer was ...
Ghazali, Wafiuddin Bin Md; Daing Idris, Daing Mohamad Nafiz Bin; Sofian, Azizul Helmi Bin; Basrawi, Mohamad Firdaus bin; Khalil Ibrahim, Thamir
Polymer is widely used in many mechanical components such as gear. With the world going to a more green and sustainable environment, polymers which are bio based are being recognized as a replacement for conventional polymers based on fossil fuel. The use of biopolymer in mechanical components especially gear have not been fully explored yet. This research focuses on biopolymer for spur gear and whether the conventional method to investigate wear characteristic is applicable. The spur gears are produced by injection moulding and tested on several speeds using a custom test equipment. The wear formation such as tooth fracture, tooth deformation, debris and weight loss was observed on the biopolymer spur gear. It was noted that the biopolymer gear wear mechanism was similar with other type of polymer spur gears. It also undergoes stages of wear which are; running in, linear and rapid. It can be said that the wear mechanism of biopolymer spur gear is comparable to fossil fuel based polymer spur gear, thus it can be considered to replace polymer gears in suitable applications.
Aistov, I. P.; Shtripling, L. O.; Svishchev, A. V.
The paper presents gear pump constituent parts operation and installation actual errors impacton the gearing overlapping coefficient value. The gearing overlapping coefficient values are shown to be less than 1 at which pump gear teeth contact opening takes place for the experimental gear pump taking into account the unit parts manufacturing and installation actual errors. In this case pump gearing dynamic loads and gears teeth contact voltages increase assessment was conducted.
Chervenak, Frank A; McCullough, Laurence B
The relationship between chairs and divisions chiefs with faculty colleagues in departments of obstetrics and gynecology has important but heretofore unexplored ethical dimensions. Based on the ethical concept of fiduciary responsibility and contractual obligations, this paper provides ethically justified practical guidance for academic physician leaders in the identification, management, and prevention of conflicts in their relationships with faculty colleagues. The framework is developed in contrast with the fiduciary-contractual dimensions of the physician-patient relationship and is articulated in terms of the ethical principles of beneficence, respect for autonomy, and justice. The distinctive nature of the academic physician leader-colleague relationship is that beneficence-based obligations and justice-based obligations to colleagues can often justifiably override autonomy-based obligations to colleagues, about which it is crucial for academic leaders to be transparent in making and implementing leadership decisions.
Iorio, A.F.; Crespi, J.C.
After ten year service in Atucha Nuclear Station a gear belonging to a pressurized heavy water reactor refuelling machine, failed. The gear box was used to transmit motion to the inlet-outlet heavy-water valve of that machine. Visual examination of the gear device revealed an absence of lubricant and several gear teeth were broken off at the root. The gear motion was transmitted from a speed-reducing device with controlled adjustable times in order to produce a right fitness of the valve closure. The main cause of gear failure was due to misalignment produced during assembly or in-service operation. It is suggested to control periodically the level of oil lubricant. (orig./IHOE) [de
Hodek, J; Zemko, M; Shykula, P
International audience; This paper presents a finite element model of a gear induction hardening process. The gear was surface-heated by an induction coil and quickly cooled by spraying water. The finite element model was developed as a three-dimensional model. The electromagnetic field, temperature field, stress distribution and microstructure distribution were examined. Temperature and microstructural characteristics were measured and used. The gear material data was obtained in part by mea...
In this study, a gear shifting mechanism was designed and applied to make the shifting process faster and less destructible for the driver. The new device must be reliable, has a small dimensions, low construction and maintenance cost. This paper aims to improve gear shifting process using devices as: a manual four speed gear box, four pneumatic double acting cylinders, four pneumatic two position five ways directional control valves, Programmable Logic Controller (PLC) LOGO unit, an electric...
... 29 Labor 7 2010-07-01 2010-07-01 false Gear requiring welding. 1919.19 Section 1919.19 Labor... (CONTINUED) GEAR CERTIFICATION Certification of Vessels' Cargo Gear § 1919.19 Gear requiring welding. Chains or other gear which have been lengthened, altered or repaired by welding shall be properly heat...
Intervention studies This dissertation describes three trials in which the effectiveness of three preventive interventions for youth were tested in the Netherlands. The interventions aim to improve the social and emotional development of children in elementary school (PATHS), reduce alcohol use and
Zhang, Enguang; Chen, Min; Deng, Baoqing
The parametric equation of the theoretical contour curve of cycloid gear was established in this paper. Using the NX10.0 software, parametric design of cycloidal gear profile curve was carried out, and the radius of curvature with the contour curve of cycloid gear was analyzed. The consistency between the simulation results and the theoretical design results was verified by assembly analysis, and the parametric drive of the cycloidal gear was verified simultaneously.
Dean, J; Forsberg, R C; Mendlovitz, S
At the end of history's bloodiest century and the outset of a new millennium, we have an opportunity to fulfil one of humanity's oldest dreams: making the world largely free of war. Global changes make this goal achievable. Nuclear weapons have shown the folly of war. For the first time, there is no war and no immediate prospect of war among the main military powers. For the first time, many proven measures to prevent armed conflict, distilled in the crucible of this century's wars, are available. If systematically applied, these measures can sharply decrease the frequency and violence of war, genocide, and other forms of deadly conflict. To seize the opportunity, nations should adopt a comprehensive programme to reduce conventional armaments and armed conflict. This programme will complement and strengthen efforts to eliminate nuclear arms. To assure its ongoing worldwide implementation, the conventional reduction programme should be placed in a treaty framework. We propose a four-phased process, with three treaties, each lasting five to ten years, to lay the groundwork for the fourth treaty, which will establish a permanent international security system. The main objectives of the treaties are to achieve: 1. A verified commitment to provide full transparency on conventional armed forces and military spending, not to increase forces during negotiations on arms reductions, and to increase the resources allocated to multilateral conflict prevention and peacekeeping. 2. Substantial worldwide cuts in national armed forces and military spending and further strengthening of United Nations and regional peacekeeping and peace-enforcement capabilities. 3. A trial of a watershed commitment by participating nations, including the major powers, not to deploy their armed forces beyond national borders except in a multilateral action under UN or regional auspices. 4. A permanent transfer to the UN and regional security organizations of the authority and capability for armed
Update on Law-Related Education, 1991
Presents a lesson plan for teaching students basic conflict resolution techniques. Calls upon students to identify issues that can lead to interpersonal confrontation, use active listening techniques, and analyze and select alternatives to conflict. Includes handouts, discussion topics, and an explanation of methods of conflict resolution. (SG)
A comprehensive review of HIV/STI prevention and sexual and reproductive health services among sex Workers in Conflict-Affected Settings: call for an evidence- and rights-based approach in the humanitarian response.
Ferguson, Alyssa; Shannon, Kate; Butler, Jennifer; Goldenberg, Shira M
While the conditions in emergency humanitarian and conflict-affected settings often result in significant sex work economies, there is limited information on the social and structural conditions of sex work in these settings, and the impacts on HIV/STI prevention and access to sexual and reproductive health (SRH) services for sex workers. Our objective was to comprehensively review existing evidence on HIV/STI prevention and access to SRH services for sex workers in conflict-affected settings globally. We conducted a comprehensive review of all peer review (both epidemiological and qualitative) and grey literature published in the last 15 years (2000-2015), focusing on 1) HIV/STI vulnerability or prevention, and/or 2) access to SRH services for sex workers in conflict-affected settings. Five databases were searched, using combinations of sex work, conflict/mobility, HIV/STI, and SRH service terms. Relevant peer-reviewed and grey literature were also hand-searched, and key papers were cross-referenced for additional material. Five hundred fifty one records were screened and 416 records reviewed. Of 33 records describing HIV/STI prevention and/or access to SRH services among sex workers in conflict-affected settings, 24 were from sub-Saharan Africa; 18 studies described the results of primary research (13 quantitative, 3 qualitative, 2 mixed-methods) and 15 were non-primary research (e.g., commentaries, policy reports, programmatic manuals). Available evidence indicated that within conflict-affected settings, SWs' capacity to engage in HIV/STI prevention and access SRH services is severely undermined by social and structural determinants including widespread violence and human rights violations, the collapse of livelihoods and traditional social structures, high levels of displacement, and difficulties accessing already scant health services due to stigma, discrimination and criminalization. This review identified significant gaps in HIV/STI and SRH research, policy
Kobayashi, M.; Yamamoto, S.; Numajiri, S.; Nakajima, K. [Mitsubishi Motors Corp., Tokyo (Japan)
To reduce vibration and noise of gears compared with ordinary steel gears for four cycle diesel engine of small commercial vehicles, austempered ductile iron (ADI) gears have been developed, which have excellent mechanical properties and vibration damping properties equivalent to steel gears. ADI is a material with tensile strength of 1,000 MPa, which is made by austempering the ductile iron to change matrix texture into tough bainite. For a new process method of ADI gears, austempering is conducted after gear cutting, and shaving is conducted, finally. Gear materials before austempering can be smoothly machined without deteriorating their machinability, to produce highly accurate gears. Fifteen percent of noise can be reduced for ADI gears during idling of engine, where 0.7 dB can be reduced in the noise level. The ADI gears provide superior pitting resistance to ordinary steel gears. They have nearly equivalent dedendum bending fatigue strength to ordinary soft nitrided steel gears. 6 refs., 12 figs., 2 tabs.
Mo, Shuai; Zhang, Yidu; Wu, Qiong; Wang, Feiming; Matsumura, Shigeki; Houjoh, Haruo
Load sharing behavior is very important for power-split gearing system, star gearing reducer as a new type and special transmission system can be used in many industry fields. However, there is few literature regarding the key multiple-split load sharing issue in main gearbox used in new type geared turbofan engine. Further mechanism analysis are made on load sharing behavior among star gears of star gearing reducer for geared turbofan engine. Comprehensive meshing error analysis are conducted on eccentricity error, gear thickness error, base pitch error, assembly error, and bearing error of star gearing reducer respectively. Floating meshing error resulting from meshing clearance variation caused by the simultaneous floating of sun gear and annular gear are taken into account. A refined mathematical model for load sharing coefficient calculation is established in consideration of different meshing stiffness and supporting stiffness for components. The regular curves of load sharing coefficient under the influence of interactions, single action and single variation of various component errors are obtained. The accurate sensitivity of load sharing coefficient toward different errors is mastered. The load sharing coefficient of star gearing reducer is 1.033 and the maximum meshing force in gear tooth is about 3010 N. This paper provides scientific theory evidences for optimal parameter design and proper tolerance distribution in advanced development and manufacturing process, so as to achieve optimal effects in economy and technology.
Ma, Hui; Pang, Xu; Zeng, Jin; Wang, Qibin; Wen, Bangchun
This paper investigates the dynamic behaviors of a perforated gear system considering effects of the gear crack propagation paths and this study focuses on the effects of a crack propagating through the rim on the time-varying mesh stiffness (TVMS) and vibration responses. Considering the effects of the extended tooth contact, a finite element (FE) model of a gear pair is established based on ANSYS software. TVMS of the perforated gear with crack propagating through tooth and rim are calculated by using the FE model. Furthermore, a lumped mass model is adopted to investigate the vibration responses of the perforated gear system. The results show that there exist three periods related to slots of the gear body in a rotating period of the perforated gear. Gear cracks propagating through tooth and rim both reduce the gear body stiffness and lead to reduction of TVMS besides the crack tooth contact moment, and the TVMS weakening for the former is less than that for the latter. Moreover, the results also show that the gear crack propagating through the rim (CPR) has a greater effect on vibration responses than the gear crack propagating through the tooth (CPT) under the same crack level. Vibration level increases with the increasing crack depth, especially for the gear with CPR.
Intervention studies This dissertation describes three trials in which the effectiveness of three preventive interventions for youth were tested in the Netherlands. The interventions aim to improve the social and emotional development of children in elementary school (PATHS), reduce alcohol use and mental health problems in students in secondary education (Preventure), and empower adolescent second generation migrants (POWER). The results revealed no effectiveness of the PATHS intervention, w...
... and extent of gear already placed in the sea and must not place themselves or their fishing gear so as..., fishing gear, net scraps, bale straps, plastic bags, oil drums, petroleum containers, oil, toxic chemicals...
... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Gear restrictions. 654.22 Section 654.22..., DEPARTMENT OF COMMERCE STONE CRAB FISHERY OF THE GULF OF MEXICO Management Measures § 654.22 Gear... be located on the top horizontal section of the trap. If the throat is longer in one dimension, the...
Parkes, Colin Murray; Attig, Thomas; Bendiksen, Robert; Cabrera, Fernando; Corr, Charles; Cox, Gerry; Faust, Susanna; Fulton, Robert; Jupp, Peter; Kallenberg, Kjell; Lamers, Elizabeth; Lamers, William; Long, Scott; McKissock, Diane; McKissock, Mal; Morgan, Mary Ann; Papadatou, Danai; Stevenson, Robert; Stoddard, Sandol; Weiss, Robert; Wrenn, Marcy
Specialists in death, dying, and bereavement and their consequences for individuals, families, and communities have experience and research findings that are relevant to an understanding of the reactions of individuals faced by deadly violence. At such times, powerful emotions and ingrained patterns of thought and behavior can given rise to disproportionate responses that may feed into cycles of violence. An extended table shows how professionals helping individuals and families faced with violent death share common aims with those aiming to help larger social units faced with armed attacks. It follows that these professionals should work together to improve death education, to prepare people for possible deadly violence and, where possible, to suggest alternatives, to create secure places and relationships in which communication becomes possible, bad news can be broken and understood, feelings examined, differences reconciled, and people can redirect anger into the prevention of escalation rather than its perpetuation. All of these activities hold out hope that cycles of deadly violence can be broken as well as mitigating the consequences when they are not. The undoubted success of the worldwide palliative care movement resulted from the recognition of serious deficiencies in existing services, the provision of an inclusive, holistic, program that extends across medical, social psychological, and spiritual realms of discourse, providing care for patients and their families, irrespective of wealth, race, religion, and political persuasion, by dedicated leaders and teams backed by education and information services and organized across geographical boundaries. It is argued here that the time is ripe for a similar commitment to bring to an end the scandal of armed conflict by a similarly multidisciplinary, multicultural effort to relieve the suffering that both causes and results from armed conflict. This must remain independent of race, religion, political
Zakrajsek, James J.; Handschuh, Robert F.; Lewicki, David G.; Decker, Harry J.
This paper summarized the results of a study in which three different vibration diagnostic methods were used to detect gear tooth fracture in a high contact ratio face gear mesh. The NASA spiral bevel gear fatigue test rig was used to produce unseeded fault, natural failures of four face gear specimens. During the fatigue tests, which were run to determine load capacity and primary failure mechanisms for face gears, vibration signals were monitored and recorded for gear diagnostic purposes. Gear tooth bending fatigue and surface pitting were the primary failure modes found in the tests. The damage ranged from partial tooth fracture on a single tooth in one test to heavy wear, severe pitting, and complete tooth fracture of several teeth on another test. Three gear fault detection techniques, FM4, NA4*, and NB4, were applied to the experimental data. These methods use the signal average in both the time and frequency domain. Method NA4* was able to conclusively detect the gear tooth fractures in three out of the four fatigue tests, along with gear tooth surface pitting and heavy wear. For multiple tooth fractures, all of the methods gave a clear indication of the damage. It was also found that due to the high contact ratio of the face gear mesh, single tooth fractures did not significantly affect the vibration signal, making this type of failure difficult to detect.
Shen, Haidong; Li, Zhiqiang; Qi, Lele; Qiao, Liang
Gear pump is the most widely used volume type hydraulic pump, and it is the main power source of the hydraulic system. Its performance is influenced by many factors, such as working environment, maintenance, fluid pressure and so on. It is different from the gear transmission system, the internal flow field of gear pump has a greater impact on the gear life, therefore it needs to consider the internal hydraulic system when predicting the gear fatigue life. In this paper, a certain aircraft gear pump as the research object, aim at the typical failure forms, gear contact fatigue, of gear pump, proposing the prediction method based on the virtual simulation. The method use CFD (Computational fluid dynamics) software to analyze pressure distribution of internal flow field of the gear pump, and constructed the unidirectional flow-solid coupling model of gear to acquire the contact stress of tooth surface on Ansys workbench software. Finally, employing nominal stress method and Miner cumulative damage theory to calculated the gear contact fatigue life based on modified material P-S-N curve. Engineering practice show that the method is feasible and efficient.
Man, Zhihong; Wang, Wenyi; Khoo, Suiyang; Yin, Juliang
In this paper, the synchronous signal average of gear mesh vibration signals is modelled with the multiple modulated sinusoidal representations. The signal model parameters are optimised against the measured signal averages by using the batch learning of the least squares technique. With the optimal signal model, all components of a gear mesh vibration signal, including the amplitude modulations, the phase modulations and the impulse vibration component induced by gear tooth cracking, are identified and analysed with insight of the gear tooth crack development and propagation. In particular, the energy distribution of the impulse vibration signal, extracted from the optimal signal model, provides sufficient information for monitoring and diagnosing the evolution of the tooth cracking process, leading to the prognosis of gear tooth cracking. The new methodologies for gear mesh signal modelling and the diagnosis of the gear tooth fault development and propagation are validated with a set of rig test data, which has shown excellent performance.
A type of gear is proposed based on the interaction of individual multipoles. The underlying principle relies on previously unknown continuous degenerate ground states for pairs of interacting multipoles which are free to rotate around specific axes. These special rotation axes, in turn, form a one-parameter family of possible configurations. This allows for the construction of magnetic bevel gears with any desired inclination angle between the in- and output axes. Further, the design of gear systems with more than two multipoles is possible and facilitates tailored applications. Ultimately, an analogy between multipoles and mechanical gears is revealed. In contrast to the mechanical case, the multipole "teeth" mesh smoothly. As an illustrative application, the example of a quadrupole-dipole interaction is then used to construct a 1 ∶2 gear ratio.
Alexandre Luís Gasparin
Full Text Available The focus of this paper is to establish a characterisation method for seven polyamide (PA grades to determine the major material to manufacture an automotive worm gear. The composite properties were measured according to the worm gear loadings: tensile strength, Young's modulus, abrasion and impact resistance. They were also correlated to the PA moisture absorption and its glass fibre (GF reinforcement. The data from mechanical tests were applied in the finite element analysis (FEA using the von Mises stress criterion. Before the rig tests of the PA worm gears, the injection process was evaluated, through the capillary rheometry. A higher difficulty to process PA 6/6 30% GF was found, due to its lower apparent viscosity. In the end, the influence of moisture absorption was as decisive to the gear's material selection as the GF to the pinion. Thus, the PAs with the best performance were: PA 6 with 30% GF (gear and with PA 60% GF (pinion.
Fuller, Jason C.; Chassin, David P.; Pratt, Robert G.; Hauer, Matthew; Tuffner, Francis K.
Disclosed herein are representative embodiments of methods, apparatus, and systems for distributing a resource (such as electricity) using a resource allocation system. One of the disclosed embodiments is a method for operating a transactive thermostatic controller configured to submit bids to a market-based resource allocation system. According to the exemplary method, a first bid curve is determined, the first bid curve indicating a first set of bid prices for corresponding temperatures and being associated with a cooling mode of operation for a heating and cooling system. A second bid curve is also determined, the second bid curve indicating a second set of bid prices for corresponding temperatures and being associated with a heating mode of operation for a heating and cooling system. In this embodiment, the first bid curve, the second bid curve, or both the first bid curve and the second bid curve are modified to prevent overlap of any portion of the first bid curve and the second bid curve.
de Figueiredo, John M
The objective of this article is to show that bicultural hybridization for the prevention of demoralization is anchored on the discovery of certain thematic areas (cultural receptors) in which social roles or cultural mandates are missing, unclear, ambiguous or congruent. The specific setting is the history of Goa, a former Portuguese territory on the western coast of India. Both published and unpublished sources of information were studied. Education, occupation and income, the three dimensions of social class, were less dominant than other aspects of the Hindu caste system, such as birth into a group viewed as a caste, observance of marriage circles, regulations of kinship and inheritance, and identification with a location. These other aspects were preserved as much as possible. The result was the conversion of the caste system into a system more akin to social class. Other examples of cultural receptors were found. A key step in the adaptation to acculturative stress is the discovery of cultural receptors in both cultures and the development of meaningful interconnections among those receptors. Psychotherapy attempts the restoration of morale. To be effective, therapists should consider the hierarchical organization of symbols and sentiments in the patient's culture.
Full Text Available Background: Oxbow lakes are abundant in indigenous fishes, but they are subject to unsustainable fishing practices, potential overexploitation, and indiscriminate use of fine-meshed fishing gear. To quantify the catch per unit effort (CPUE and impact of fishing gears on fish abundance, a survey was carried out in an oxbow lake in eastern India. Methods: The gear-wise CPUE for fish caught in per unit hour of operation was calculated by dividing the total sampling gear catch in biomass, which is the observed value of fish caught by a particular gear, by the total sampling effort hours. A value of P 71%. Cone-framed cast net hauled the maximum catch in biomass (31.51%, and gill nets contributed the maximum number of fish (64.92%. The lower CPUE values of line and hook, gill net, cone-framed cast net and long lines identified them as the most harmful among all gears. Conclusion: Indiscriminate use of gear, particularly line and hook, gill nets, cone-framed cast nets, and long lines, demands regulations and preventions concerning such gear to obtain higher fish abundance.
handschuh, Robert F.; Krantz, Timothy L.
A series of bench-top experiments was conducted to determine the effects of metallic debris being dragged through meshing gear teeth. A test rig that is typically used to conduct contact fatigue experiments was used for these tests. Several sizes of drill material, shim stock and pieces of gear teeth were introduced and then driven through the meshing region. The level of torque required to drive the "chip" through the gear mesh was measured. From the data gathered, chip size sufficient to jam the mechanism can be determined.
K. Rajasuthan*, G. Balaji, M. Palpandi
In our project bicycle is driven with a series of spur gears which will increase the speed of bicycle and also the bicycles becomes more efficient than a conventional sprocket driven bicycle. Spur gears are used in series to transmit power from the pedal to the rear wheel of the bicycle. This bicycle enables us to put less effort for pedaling. For a very low input effort, we can get maximum output. Distance covered by this gear driven bicycle for few minutes of pedaling will also be 3-4 times...
van Doorn, G. Sander; Schlichting, CD; Mousseau, TA
Intralocus sexual conflict arises when there are sex-specific optima for a trait that is expressed in both sexes and when the constraint of a shared gene pool prevents males and females from reaching their optima independently. This situation may result in a negative intersexual correlation for
Aleksandar R. Grkić
Full Text Available Gear boxes, i. e. the realization of their functions, especially gear shift, have a big impact on vehicle operation quality through their effects on the performance of vehicles and their comfort. This paper shows a method of modeling the transition process during gear shifting in planetary gear trains. The simulation model is developed with in order to provide virtual research of planetary gear trains, which would positively decrease the number of real prototypes, thus considerably saving time and contributing to the quality improvement of the final product (planetary gear train and vehicles in general. Introduction Modeling of gear shift processes has been carried out on the planetary gear type Ravigneaux used in planetary gear trains of motor vehicles. The model was developed modularly, so that more simulation models can be added to the whole. At the same time each subsystem is a model for itself and can be used independently from the main model. Simplified engine model Bearing in mind that, for the simulation of the planetary gear which is the subject of this paper, the necessary input parameters are in the form of engine torque Mm, angular velocity and motor ωm moment of inertia of rotating engine components reduced to the input shaft gear, a simplified model of an internal combustion engine has been formed. Model of external load External load resistance is in the form of the torque Mt occurring on the drive wheel of the vehicle. On the other hand, this load is defined by the moment of inertia of rotating elements from the planetary gear to the drive wheel, reduced to the output shaft. Model of friction transmission simulation Transmission power control in planetary gears is achieved through friction components. The output size of this subsystem is the moment of carrying the friction assembly. Simulation model of the planetary gear train The model simulation of the planetary gear type Ravigneaux was formed in accordance with the kinematic
Rasmussen, Peter Omand; Andersen, Torben Ole; Jørgensen, Frank Thorleif
This paper presents calculation and measurement results of a highperformance permanent-magnetic gear. The analyzed permanent-magnetic gear has a gear ratio of 5.5 and is able to deliver 27 N.m. The analysis has shown that special attention needs to be paid to the system where the gear is to be in...
Full Text Available An automatic gear sorting system based on monocular vision is proposed in this paper. A CCD camera fixed on the top of the sorting system is used to obtain the images of the gears on the conveyor belt. The gears׳ features including number of holes, number of teeth and color are extracted, which is used to categorize the gears. Photoelectric sensors are used to locate the gears׳ position and produce the trigger signals for pneumatic cylinders. The automatic gear sorting is achieved by using pneumatic actuators to push different gears into their corresponding storage boxes. The experimental results verify the validity and reliability of the proposed method and system.
National Oceanic and Atmospheric Administration, Department of Commerce — The Southeast Fisheries Science Center Mississippi Laboratories is responsible for new gear development and testing to reduce bycatch and incidental interactions of...
Hood, Adrian; LaBerge, Kelsen; Lewicki, David; Pines, Darryll
Seeded fault experiments were conducted on the planetary stage of an OH-58C helicopter transmission. Two vibration based methods are discussed that isolate the dynamics of the sun gear from that of the planet gears, bearings, input spiral bevel stage, and other components in and around the gearbox. Three damaged sun gears: two spalled and one cracked, serve as the focus of this current work. A non-sequential vibration separation algorithm was developed and the resulting signals analyzed. The second method uses only the time synchronously averaged data but takes advantage of the signal/source mapping required for vibration separation. Both algorithms were successful in identifying the spall damage. Sun gear damage was confirmed by the presence of sun mesh groups. The sun tooth crack condition was inconclusive.
Kunz, Robert F. (Inventor); Medvitz, Richard B. (Inventor); Hill, Matthew John (Inventor)
A gear and drive system utilizing the gear include teeth. Each of the teeth has a first side and a second side opposite the first side that extends from a body of the gear. For each tooth of the gear, a first extended portion is attached to the first side of the tooth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates. The gear may be utilized in drive systems that may have high rotational speeds, such as speeds where the tip velocities are greater than or equal to about 68 m/s. Some embodiments of the gear may also utilize teeth that also have second extended portions attached to the second sides of the teeth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates.
Marston, R M
Instrumentation and Test Gear Circuits Manual provides diagrams, graphs, tables, and discussions of several types of practical circuits. The practical circuits covered in this book include attenuators, bridges, scope trace doublers, timebases, and digital frequency meters. Chapter 1 discusses the basic instrumentation and test gear principles. Chapter 2 deals with the design of passive attenuators, and Chapter 3 with passive and active filter circuits. The subsequent chapters tackle 'bridge' circuits, analogue and digital metering techniques and circuitry, signal and waveform generation, and p
Rehren, Jennifer; Wolff, Matthias; Jiddawi, Narriman
East African coastal communities highly depend on marine resources for not just income but also protein supply. The multi-species, multi-gear nature of East African fisheries makes this type of fishery particularly difficult to manage, as there is a trade-off between maximizing total catch from all gears and species and minimizing overfishing of target species and the disintegration of the ecosystem. The use and spatio-temporal overlap of multiple gears in Chwaka Bay (Zanzibar) has led to severe conflicts between fishermen. There is a general concern of overfishing in the bay because of the widespread use of small mesh sizes and destructive gears such as dragnets and spear guns. We constructed an Ecopath food web model to describe the current trophic flow structure and fishing pattern of the bay. Based on this model, we explored the impact of different gears on the ecosystem and the fishing community in order to give advice for gear based management in the bay. Results indicate that Chwaka bay is a productive, shallow water system, with biomass concentrations around the first and second trophic level. The system is greatly bottom-up driven and dominated by primary producers and invertebrates. The trophic and network indicators as well as the community energetics characterize Chwaka Bay as relatively mature. Traps and dragnets have the strongest impact on the ecosystem and on the catches obtained by other gears. Both gears potentially destabilize the ecosystem by reducing the biomass of top-down controlling key species (including important herbivores of macroalgae). The dragnet fishery is the least profitable, but provides most jobs for the fishing community. Thus, a complete ban of dragnets in the bay would require the provision of alternative livelihoods. Due to the low resource biomass of fish in the bay and the indication of a loss of structural control of certain fish groups, Chwaka Bay does not seem to provide scope for further expansion of the fishery
This case study illustrates alternative approaches to conflict resolution. Although the case is fictitious, it describes a situation that is common in the workplace, i.e., the attempt of a coworker to undermine the respect, power, and authority of another staff member. The purpose of this case is to not only identify several approaches to conflict resolution but also to illustrate why some approaches can be more effective than others. Clearly, conflict that is ignored and unresolved does not usually go away. It festers and eventually becomes an even more serious problem.
Schreiner, T. [Siemens AG, Power Generation, KWU, Muelheim (Germany); Heinrich, W. [Siemens AG, Power Generation, KWU, Berlin (Germany); Achtzehn, J. [Siemens AG, Power Generation, ICVW, Erlangen (Germany); Hensley, H. [Siemens Power Generation (Germany)
In the power plant industry, gears are used for increasingly higher turbine capacities. Efficiency enhancements, particularly for the combined gas and steam turbine process, lead to an increase in stresses, even for high-performance gears. Consequently, the requirements for non-destructive material testing are on the increase as well. At Siemens KWU, high-performance gears are used so far only for gas turbines with lower rating (65 MW) to adapt the gas turbine speed (5413 rpm) to the generator speed (3000 rpm/ 50 Hz or 3600 rpm/60 Hz). The gear train consists of a forged and case-hardened wheel shaft and pinion shaft made of material 17 CrNiMo 6, where the wheel shaft can be either a solid or a hollow shaft. Dimensions are typically 2.3 m length and 1 m diameter. As a rule, pinion shafts are solid. The gear design, calling for an additional torsion shaft turning inside the hollow wheel shaft, can absorb more torsional load surges and is more tolerant of deviations during gear train alignment. This design requires two additional forgings (torsion shaft and hub) and an additional bearing 2 refs.
More importantly, due to the various crises that plagued the world ranging from civil wars to border clashes etc., the importance or roles of Supra-national organisations in conflict resolution through mediatory diplomacy or otherwise cannot be over-emphasised. This is especially geared towards making the World a Haven of ...
The traditional methods of African conflict resolution have long existed and are deeply rooted in the customs and traditions of the peoples of Africa. These methods are geared towards maintaining harmonious and peaceful coexistence in the community. Colonialism introduced the modern justice system, which dominated ...
Gears are the most commonly used components in mechanical transmission systems. Their failures may cause transmission system breakdown and result in economic loss. Identification of different gear crack levels is important to prevent any unexpected gear failure because gear cracks lead to gear tooth breakage. Signal processing based methods mainly require expertize to explain gear fault signatures which is usually not easy to be achieved by ordinary users. In order to automatically identify different gear crack levels, intelligent gear crack identification methods should be developed. The previous case studies experimentally proved that K-nearest neighbors based methods exhibit high prediction accuracies for identification of 3 different gear crack levels under different motor speeds and loads. In this short communication, to further enhance prediction accuracies of existing K-nearest neighbors based methods and extend identification of 3 different gear crack levels to identification of 5 different gear crack levels, redundant statistical features are constructed by using Daubechies 44 (db44) binary wavelet packet transform at different wavelet decomposition levels, prior to the use of a K-nearest neighbors method. The dimensionality of redundant statistical features is 620, which provides richer gear fault signatures. Since many of these statistical features are redundant and highly correlated with each other, dimensionality reduction of redundant statistical features is conducted to obtain new significant statistical features. At last, the K-nearest neighbors method is used to identify 5 different gear crack levels under different motor speeds and loads. A case study including 3 experiments is investigated to demonstrate that the developed method provides higher prediction accuracies than the existing K-nearest neighbors based methods for recognizing different gear crack levels under different motor speeds and loads. Based on the new significant statistical
... Error processing SSI file About Heart Disease & Stroke Prevention Heart disease and stroke are an epidemic in ... secondhand smoke. Barriers to Effective Heart Disease & Stroke Prevention Many people with key risk factors for heart ...
term Nakba literally means catastrophe and usually refers to the Arab-Israeli war of 1948, when the state of Israel was declared and more than 700,000 Palestinians became stateless. Among Palestinians in Denmark, though, the concept of Nakba is used in two additional ways. Namely to embrace...... to a specific place of origin and that movement of conflicts or peace can be described as relations between homeland and diaspora. Based on 16 months of fieldwork among Palestinians in Denmark this paper challenges this assumption and offers a different conceptualization of conflicts on the move. The Arabic......Within the field of ‘transnational conflicts’ a wide range of studies have explored how diasporas may contribute to or diminish conflicts within their homeland by sending remittances or weapons or by partaking in NGOs. A common assumption in this literature is that conflicts are linked...
Clegg, Stewart; Mikkelsen, Elisabeth Naima; Sewell, Graham
This article examines four contemporary treatments of the problem of organizational conflict: social psychological, anthropological, neo-Darwinian, and neo-Machiavellian. Social psychological treatments of organizational conflict focus on the dyadic relationship between individual disputants....... In contrast, anthropological treatments take a more socially and historically embedded approach to organizational conflict, focusing on how organizational actors establish negotiated orders of understanding. In a break with the social psychological and anthropological approaches, neo-Darwinians explain...... the characteristics of organizational conflict by appealing to the concept of natural selection: all forms of organizational behavior, including conflictual relations, stem from the effects of heritable traits associated with a universal human nature. Finally, this article proposes a neo-Machiavellian view...
... say, "You can't watch TV until your homework is finished"; but when she's away, Dad may ... difference Taking each other's feelings seriously Generating alternative solutions together Negotiating Remember, the way you handle conflict ...
Krantz, Timothy L.; Handschuh, Robert F.
The space shuttle orbiter's body flap actuator gearing was assessed as a case study of the stresses for very heavily loaded external-internal gear pairs (meshing pinion and ring gear). For many applications, using the high point of single tooth contact (HPSTC) to locate the position of the tooth force is adequate for assessing the maximum tooth root stress condition. But for aerospace gearing such an approach may be inadequate for assessing the stress condition while also simultaneously minimizing mass. In this work specialized contact analyses and finite element methods were used to study gear tooth stresses of body flap actuator gears. The analytical solutions considered the elastic deformations as an inherent part of the solutions. The ratio for the maximum tooth stresses using the HPSTC approach solutions relative to the contact analysis and finite element solutions were 1.40 for the ring gear and 1.28 for the pinion gear.
Poder, Poul; Bramsen, Isabel
Isabel Bramsen & Poul Poder 2018. Emotional Dynamics in Conflict and Conflict Transformation. Berghof Handbook for Conflict Transformation, Online Edition. Berlin: Berghof Foundation.
Full Text Available The article presents research on the problem of two gear contact in the car gearbox. Contact stiffness is evaluated for the whole period of mesh. Also, contact stresses are evaluated in the contact place. The presented method can be used for calculating spur gear.Article in Lithuanian
Full Text Available Gear train volume optimization presents a complex problem tied to practical application in gear train manufacturing. This paper is oriented on the analysis of the problem of gear train volume minimization from a shaft axes positioning aspect. An original mathematical model has been developed where the objective function gives a minimum volume with changed shaft (spur gear axes positions, while at the same time complying with all physical constraints. An original optimization software has also been developed using RCGA (Real Coded Genetic Algorithm optimization methods. The general mathematical model was applied to three real conceptions of gear train as well as a comparative analysis of initial and optimal values. The results show a decrease of volume being directly linked to a decrease of not only space but material used to make the housing, costs, documentation formulation rate, etc.
Pharmaceutical representatives use detailing, gift giving, and the donation of free samples as a means to gain access to and influence over physicians. In biomedical ethics, there has been an ongoing debate as to whether these practices constitute an unethical conflict of interest (COI) on the part of the physician. Underlying this debate are the following antecedent questions: (1) what counts as a conflict of interest, (2) when are such conflicts unethical, and (3) how should the ethical physician respond to conflicts? This article distinguishes between two perspectives that have been developed on these issues: a reliable performance model (PM) and a trustworthiness model (TM). PM advocates argue that a conflict of interest can only be established by demonstrating that a particular influence is undermining the reliability of the physician's judgment, and this requires empirical evidence of negative patient outcomes. TM advocates, on the other hand, argue that because of the fiduciary nature of the patient-physician relationship, physicians have an obligation to develop and be worthy of patient trust. A COI, on this view, is a condition that undermines the warrant for patients to judge a physician as trustworthy. Although there is much that is right in the PM, it is argued that the TM does a better job of responsibly addressing the unique vulnerabilities of the patient. The TM is then applied to the practices of detailing, gift giving, and sample donation. It is concluded that these practices constitute an unethical conflict of interest.
Lim, Teik C.; Singh, RAJ.; Zakrajsek, James J.
Dynamic finite element analysis of a real gear housing is presented. The analysis was conducted for the housing without the rotating components (gears, shafts, and bearings). Both rigid and flexible mounting conditions for the gear housing are considered in this analysis. The flexible support simulates the realistic mounting condition on a rotorcraft, and the rigid one is analyzed for comparison purposes. The effect of gear housing stiffeners is also evaluated. The results indicate that the first six natural modes of the flexibly mounted gear housing in the 0 to 200 Hz range correspond to the translational and rotational rigid body vibration modes of the housing. Above this range, the housing plate elastic modes begin to occur. In the case of the rigid mount, only the housing plate elastic modes are observed which are verified by modal analysis experiments. Parametric studies show that the housing plate stiffeners and rigid mounts tend to increase most of the natural frequencies, the lower ones being affected the most.
Full Text Available Power transmissions that incorporate gears dissipate a significant amount of energy and noise. Thus, any improvement in their performance contributes to reducing energy consumption and noise pollution. In recent years, the opportunities offered by conventional technologies to increase gear performance have been fully exploited. Therefore, surface depositions on gear teeth have become increasingly important technologies in achieving objectives such as: improving energy performance, providing greater protection against superficial defects, increasing load capacity and reducing acoustic emissions generated during operation. However, gear coating technologies have begun to be developed, but the investigations are still insufficient. In this study, we carried out wear resistance investigations performed on fluoropolymer coatings for different working speeds, loads and lubrication conditions. The results point out that the deterioration rate of the coating increases with the increase of the working speed and the applied load. In addition, a slight lubrication, applied at the start of testing, leads to a noticeable improvement in wear behaviour. This study represents one step further in understanding the wear process of fluoropolymer coated gears
Full Text Available Gears are widely used in gearbox to transmit power from one shaft to another. Gear crack is one of the most frequent gear fault modes found in industry. Identification of different gear crack levels is beneficial in preventing any unexpected machine breakdown and reducing economic loss because gear crack leads to gear tooth breakage. In this paper, an intelligent fault diagnosis method for identification of different gear crack levels under different working conditions is proposed. First, superhigh-dimensional statistical features are extracted from continuous wavelet transform at different scales. The number of the statistical features extracted by using the proposed method is 920 so that the extracted statistical features are superhigh dimensional. To reduce the dimensionality of the extracted statistical features and generate new significant low-dimensional statistical features, a simple and effective method called principal component analysis is used. To further improve identification accuracies of different gear crack levels under different working conditions, support vector machine is employed. Three experiments are investigated to show the superiority of the proposed method. Comparisons with other existing gear crack level identification methods are conducted. The results show that the proposed method has the highest identification accuracies among all existing methods.
in public policy conflicts? And how do they incorporate principles such as fairness, inclusive representation and autonomy? - How do public administrators balance between the demands of public authorities and the needs of multiple stakeholders involved in collaborative governance processes? Based...... practices of spatial planning and urban policy in order to answer questions such as: - What dilemmas, challenges and conflicts do public administrators experience in new forms of competing rationalities of governance processes and how do they cope with it? - How do they mediate between different interests...
The Arabic term al-Nakba literally means the catastrophe and is used in Palestinian national discourse to designate the outcome of the Arab-Israeli war of 1948, when the state of Israel was declared and more than 700,000 Palestinians became stateless. Among Palestinians in Denmark, though, the co...... off what is at hand within a specific milieu at a given time, such as contemporary conflicts, artefacts and people. It is this plasticity that enables the conflict to be recreated anew and to become meaningful in new settings and at different times....
Barazzetti, L.; Previtali, M.; Roncoroni, F.
The Samsung Gear 360 is a consumer grade spherical camera able to capture photos and videos. The aim of this work is to test the metric accuracy and the level of detail achievable with the Samsung Gear 360 coupled with digital modelling techniques based on photogrammetry/computer vision algorithms. Results demonstrate that the direct use of the projection generated inside the mobile phone or with Gear 360 Action Direction (the desktop software for post-processing) have a relatively low metric accuracy. As results were in contrast with the accuracy achieved by using the original fisheye images (front and rear facing images) in photogrammetric reconstructions, an alternative solution to generate the equirectangular projections was developed. A calibration aimed at understanding the intrinsic parameters of the two lenses camera, as well as their relative orientation, allowed one to generate new equirectangular projections from which a significant improvement of geometric accuracy has been achieved.
Ahmed, Rounaq; Srinivasa Pai, P.; Sriram, N. S.; Bhat, Vasudeva
Vibration Analysis has been extensively used in recent past for gear fault diagnosis. The vibration signals extracted is usually contaminated with noise and may lead to wrong interpretation of results. The denoising of extracted vibration signals helps the fault diagnosis by giving meaningful results. Wavelet Transform (WT) increases signal to noise ratio (SNR), reduces root mean square error (RMSE) and is effective to denoise the gear vibration signals. The extracted signals have to be denoised by selecting a proper denoising scheme in order to prevent the loss of signal information along with noise. An approach has been made in this work to show the effectiveness of Principal Component Analysis (PCA) to denoise gear vibration signal. In this regard three selected wavelet based denoising schemes namely PCA, Empirical Mode Decomposition (EMD), Neighcoeff Coefficient (NC), has been compared with Adaptive Threshold (AT) an extensively used wavelet based denoising scheme for gear vibration signal. The vibration signals acquired from a customized gear test rig were denoised by above mentioned four denoising schemes. The fault identification capability as well as SNR, Kurtosis and RMSE for the four denoising schemes have been compared. Features extracted from the denoised signals have been used to train and test artificial neural network (ANN) models. The performances of the four denoising schemes have been evaluated based on the performance of the ANN models. The best denoising scheme has been identified, based on the classification accuracy results. PCA is effective in all the regards as a best denoising scheme.
H. F. Moskalyk
Full Text Available Actuality of work. Student age has the most favourable conditions for psychological, biological and social development; however, there are reasons why such natural advantages over other social groups can be completely or partially levelled. One of them is the presence of conflicts in the life of a student, a special group, among which there are women. The causes of the emergence of gender conflicts in individual social groups and the strategies for their solution have not been sufficiently explored and require further study and, therefore, are relevant. Purpose of the article is to investigate the causes of gender conflicts among students as a separate social group and to develop measures to address them and prevent them. Methodology. The research conducted in the work is based on the analysis and generalization of the causes of the emergence of gender conflicts among students, the identification of the main sources of information that form the consciousness of children and adolescents, and also influence their attitude to gender equality. Originality. The nature of gender conflicts has been quite effectively studied for a long time. However, the scope of research is limited to the most numerous social groups, such as the family, labour collective, political and public organizations, etc. Being a dynamic and socio-demographic formation, the students perform an important function in society – it takes a direct part in the transformation of all spheres of the life activity of the society. Based on the study of the objective conditions of the social environment with certain models of socialization that form the consciousness of students from early childhood, a three-component system of influence was first proposed, which is aimed at overcoming gender inequality and preventing gender conflicts among students. At the same time, the interaction of the components of the system will allow to minimize the gender inequality index in our country
Proctor, Margaret P.; Oswald, Fred B.; Krants, Timothy L.
Scuffing-like damage has been found on the tooth surfaces of gears 5 and 6 of the NASA space shuttle rudder/speed brake power drive unit (PDU) number 2 after the occurrence of a transient back-driving event in flight. Tests were conducted using a pair of unused spare flight gears in a bench test at operating conditions up to 2866 rpm and 1144 in.-lb at the input ring gear and 14,000 rpm and 234 in.-lb at the output pinion gear, corresponding to a power level of 52 hp. This test condition exceeds the maximum estimated conditions expected in a backdriving event thought to produce the scuffing damage. Some wear marks were produced, but they were much less severe than the scuffing damaged produced during shuttle flight. Failure to produce scuff damage like that found on the shuttle may be due to geometrical variations between the scuffed gears and the gears tested herein, more severe operating conditions during the flight that produced the scuff than estimated, the order of the test procedures, the use of new hydraulic oil, differences between the dynamic response of the flight gearbox and the bench-test gearbox, or a combination of these. This report documents the test gears, apparatus, and procedures, summarizes the test results, and includes a discussion of the findings, conclusions, and recommendations.
Research on mediation has shown that mediation can be an effective conflict management tool to contain intrastate conflicts, prevent escalation of low intensity conflicts, and foster de-escalation. But can ripe moments for conflict prevention effectively be anticipated? This article argues that the short-term conflict history provides a good predictor of the probability of mediation onset in low-intensity conflicts. It builds on an expected utility theory of mediation and states that conflict...
Oliveira, Jillian M; Chen, Yi; Hunter, Ian W
Actuation of a robotic endoscope with increased torque output is presented. This paper will specifically focus on the motor module section of a robotic endoscope, which comprises of a pair of motors and gear reduction assemblies. The results for the endoscope and biopsy tool stiffness, as well as the stall force and force versus speed characteristics of the motor module assembly are shown. The scope stiffness was found to be 0.006 N/degree and additional stiffness of the biopsy tools were found to be in the range of 0.09 to 0.13 N/degree. Calculations for worm gearing and efficiency are discussed.
Naik, U.G.; Neelakantan, B.
An account is given of the different types of gears and craft used to catch the pelagic and demersal fish in the inshore and estuary waters of Karwar, India. The main types of craft used during the fishing season September-May are: rampani boats, yendi boats, out-rigger boats, plank-built and dug-out canoes; important gears include: rampani, yendi, shore-seines, gill nets, boat seines, drift nets and hook and lines. Mechanized fishing, introduced during the sixties and seventies, included tra...
Kanatnikov, N.; Harlamov, G.; Kanatnikova, P.; Pashmentova, A.
The paper reviews the issue of optimization of technological process of tooth gears production of the power consumption criteria. The authors dwell on the indices used for cutting process estimation by the consumed energy criteria and their applicability in the analysis of the toothed wheel production process. The inventors proposed a method for optimization of power consumptions based on the spatial modeling of cutting pattern. The article is aimed at solving the problem of effective source management in order to achieve economical and ecological effect during the mechanical processing of toothed gears. The research was supported by Russian Science Foundation (project No. 17-79-10316).
Delsen, L.W.M.; Bauer, F.; Groß, H.; Sieglen, G.
The chapter deals with the presupposed conflict of interests between employers and employees resulting from a decoupling of operating hours and working times. It starts from the notion that both long operating hours and flexibility are relative concepts. As there is some discretion, the ultimate
Clegg, Stewart; Mikkelsen, Elisabeth Naima; Sewell, Graham
the characteristics of organizational conflict by appealing to the concept of natural selection: all forms of organizational behavior, including conflictual relations, stem from the effects of heritable traits associated with a universal human nature. Finally, this article proposes a neo-Machiavellian view...
Richey, Lisa Ann; Budabin, Alexandra Cosima
From serving as United Nations ambassadors to appearing as spokespersons for major NGO campaigns, global celebrities have become increasingly important in international development assistance. Acting as “aid celebrities,” they are indelibly linked with humanitarian work and public engagement.2 In......, conflict, and development in Africa....
... Contact Aging & Health A to Z Find a Geriatrics Healthcare Professional Medications & Older Adults Making Your Wishes ... Prevention Hearing Loss Heart Attack High Blood Pressure Nutrition Osteoporosis Shingles Skin Cancer Related News Quitting Smoking, ...
Rasmussen, Peter Omand; Andersen, Torben Ole; Jørgensen, Frank Thorleif
This paper presents calculation and measurement results of a highperformance permanent-magnetic gear. The analyzed permanent-magnetic gear has a gear ratio of 5.5 and is able to deliver 27 N.m. The analysis has shown that special attention needs to be paid to the system where the gear...... is to be installed because of a low natural torsion spring constant. The analyzed gear was also constructed in practice in order to validate the analysis and predict the efficiency. The measured torque from the magnetic gear was only 16 N-m reduced by the large end-effects. A systematic analysis of the 1055...... in the bearings and jess end-effects caused by relative ly short stack, an impressive efficiency estimated at 96% can be obtained. Comparison with c1assical mechanical gears has shown that the magnetic gear has a bette r efficiency and a comparable torque per volume density. Finally, it is concluded...
Dempsey, Paula J.; Antolick, Lance J.; Branning, Jeremy S.; Thomas, Josiah
Tests were performed on two spiral bevel gear sets in the NASA Glenn Spiral Bevel Gear Fatigue Test Rig to simulate the fielded failures of spiral bevel gears installed in a helicopter. Gear sets were tested until damage initiated and progressed on two or more gear or pinion teeth. During testing, gear health monitoring data was collected with two different health monitoring systems. Operational parameters were measured with a third data acquisition system. Tooth damage progression was documented with photographs taken at inspection intervals throughout the test. A software tool was developed for fusing the operational data and the vibration based gear condition indicator (CI) data collected from the two health monitoring systems. Results of this study illustrate the benefits of combining the data from all three systems to indicate progression of damage for spiral bevel gears. The tool also enabled evaluation of the effectiveness of each CI with respect to operational conditions and fault mode.
National Aeronautics and Space Administration — A major component of airframe noise for commercial transport aircraft is the deployed landing gear. The noise from the gear originates due to complex, unsteady bluff...
Cai, Yu-yu; Wang, Wei
Based on the gear meshing theory, after the process of construction is discussed, the mathematical model about profile curve equation, conjugate equation and action line equation is built. It provides some theoretical proofs for research of performance and manufacture of cosine-gear. In this article, the profile curve equation of cosine gear is introduced, and the conjugate equation is deduced. The solid model of cosine-gear is built by example with Pro/E software, and the meshing process of a pair of cosine-gears is simulated. From the result of simulating, it can detect the interference and the dynamic characteristics of a pair of cosine gears quickly, and during the meshing process, there is no meshing interference. Moreover, the cosine gear is line contact. It is significant to improve the efficiency of design and manufacturing of cosine gear.
Tufan Gürkan YILMAZ
Full Text Available In this study, mathematical modelling of asymmetric involute spur gears was situated in by Litvin approach. In this context, firstly, mathematical expressions of rack cutter which manufacture asymmetric involute spur gear, then mathematical expression of asymmetric involute spur gear were obtained by using differential geometry, coordinate transformation and gear theory. Mathematical expressions were modelled in MATLAB and output files including points of involute spur gear’s teeth were designed automatically thanks to macros.
Van Der Woude, L. H V; Bosmans, I.; Bervoets, B.; Veeger, H. E J
Handrim wheelchair propulsion is a straining form of ambulation. In contrast, arm crank exercise in laboratory settings has shown a higher degree of gross mechanical efficiency and increased levels of peak power output. Moreover, arm crank exercise can be conducted at different gear ratios and in
van der Woude, L H; Bosmans, I; Bervoets, B; Veeger, DirkJan (H. E. J.)
Handrim wheelchair propulsion is a straining form of ambulation. In contrast, arm crank exercise in laboratory settings has shown a higher degree of gross mechanical efficiency and increased levels of peak power output. Moreover, arm crank exercise can be conducted at different gear ratios and in
Blagojevic Ivan A.
Full Text Available Many studies have proved that elements of driver’s behavior related to gear selection have considerable influence on the fuel consumption. Optimal gear shifting is a complex task, especially for inexperienced drivers. This paper presents an implemented idea for gear shifting optimization with the aim of fuel consumption minimization with more efficient engine working regimes. Optimized gear shifting enables the best possible relation between vehicle motion regimes and engine working regimes. New theoretical-experimental approach has been developed using On-Board Diagnostic technology which so far has not been used for this purpose. The matrix of driving modes according to which tests were performed is obtained and special data acquisition system and analysis process have been developed. Functional relations between experimental test modes and adequate engine working parameters have been obtained and all necessary operations have been conducted to enable their use as inputs for the designed algorithm. The created Model has been tested in real exploitation conditions on passenger car with Otto fuel injection engine and On-Board Diagnostic connection without any changes on it. The conducted tests have shown that the presented Model has significantly positive effects on fuel consumption which is an important ecological aspect. Further development and testing of the Model allows implementation in wide range of motor vehicles with various types of internal combustion engines.
Merino Martinez, R.; Snellen, M.; Simons, D.G.
Airframe noise is becoming increasingly important during approach, even reaching higher noise levels than the engines in some cases. More people are a_ected due to low ight altitudes and _xed tra_c routing associated with typical approaches. For most air- craft types, the landing gear system is a
... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Gear limitations. 679.24 Section 679.24 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION... type. (v) The areas must not be within a designated Steller sea lion protection area at any time of the...
Dyundik, O. S.; Zgonnik, I. P.
The analysis of technical and technological solutions to reduce the influence of dynamic intermating process to vibroactivity of a gear drive is carried out. The problem of a complete elimination has no solution due to a discrete way of power flow transformation by a gear drive. It is shown that a reduction of mesh stiffness is a controlled parameter in vibroactivity decrease. We have proposed to reduce the stiffness by means of a gear rim radial cut that provides small initial and stepwise variable stiffness of gearing. The technical solutions resulting in a smooth, dependent on a power flow running of stiffness by means of built-in control chain and usage of elastomeric materials are given. As a result, it is noted that the reduction of mesh stiffness at the same time leads to the increase in static deformation δ, and the dynamic load under intermating decreases. Elastomeric parameters’ variation t can provide the achievement of calculated mesh stiffness, depending on a variable power flow.
Stoyanov, Svetlin; Dobrev, Vasko; Dobreva, Antoaneta
The paper presents the application aspects of computer technologies concerning the process of creating theoretical contact models of planetary gear trains using Abaqus/Explicit. The necessary assumptions, constrains and specific features of these gear drives are discussed in details. The models created are appropriate and useful tools for computer simulation research of the dynamic behaviour of planetary gear trains.
... Automatic brakes; speed reduction gear. [Statutory Provisions] Each locomotive and haulage car used in an... permit automatic brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic brakes; speed reduction gear. 75.1404...
... strengtheners, ropes, lines, or chafing gear, on the top of a trawl net, except that one splitting strap and one... top) possessed or used by vessels fishing with scallop dredge gear shall not be smaller than 10-inch... restrictions. No chafing gear or cookies shall be used on the top of a scallop dredge. (ii) Link restrictions...
Radzevich, Stephen P
Presents the DG/K-based method of surface generation, a novel and practical mathematical method for designing gear cutting tools with optimal parameters. This book proposes a scientific classification for the various kinds of the gear machining meshes, discussing optimal designs of gear cutting tools.
Full Text Available With the continuous development of national economy, big gear was widely applied in metallurgy and mine domains. So, big gear plays an important role in above domains. In practical production, big gear abrasion and breach take place often. It affects normal production and causes unnecessary economic loss. A kind of intelligent test method was put forward on worn big gear mainly aimed at the big gear restriction conditions of high production cost, long production cycle and high- intensity artificial repair welding work. The measure equations transformations were made on involute straight gear. Original polar coordinate equations were transformed into rectangular coordinate equations. Big gear abrasion measure principle was introduced. Detection principle diagram was given. Detection route realization method was introduced. OADM12 laser sensor was selected. Detection on big gear abrasion area was realized by detection mechanism. Tested data of unworn gear and worn gear were led in designed calculation program written by Visual Basic language. Big gear abrasion quantity can be obtained. It provides a feasible method for intelligent test and intelligent repair welding on worn big gear.
McCarthy, Philip; Feltham, Graham; Ekmekci, Alis
Dynamic similarity during scaled model testing is difficult to maintain. Forced boundary layer transition via a surface protuberance is a common method used to address this issue, however few guidelines exist for the effective tripping of complex geometries, such as aircraft landing gears. To address this shortcoming, preliminary wind tunnel tests were performed at Re = 500,000. Surface transition visualisation and pressure measurements show that zigzag type trips of a given size and location are effective at promoting transition, thus preventing the formation of laminar separation bubbles and increasing the effective Reynolds number from the critical regime to the supercritical regime. Extension of these experiments to include three additional tripping methods (wires, roughness strips, CADCUT dots) in a range of sizes, at Reynolds number of 200,000 and below, have been performed in a recirculating water channel. Analysis of surface pressure measurements and time resolved PIV for each trip device, size and location has established a set of recommendations for successful use of tripping for future, low Reynolds number landing gear testing.
The Arabic term al-Nakba literally means the catastrophe and is used in Palestinian national discourse to designate the outcome of the Arab-Israeli war of 1948, when the state of Israel was declared and more than 700,000 Palestinians became stateless. Among Palestinians in Denmark, though......, the concept of Nakba is used in two additional ways. Namely, to embrace their everyday life in Denmark, and to single out specific contemporary political events, like the publishing of the cartoons of the Prophet Muhammad in 2005, local clashes with the Danish police and the Israeli invasions of Lebanon...... off what is at hand within a specific milieu at a given time, such as contemporary conflicts, artefacts and people. It is this plasticity that enables the conflict to be recreated anew and to become meaningful in new settings and at different times....
Halken, S; Høst, A
, breastfeeding should be encouraged for 4-6 months. In high-risk infants a documented extensively hydrolysed formula is recommended if exclusive breastfeeding is not possible for the first 4 months of life. There is no evidence for preventive dietary intervention neither during pregnancy nor lactation...... populations. These theories remain to be documented in proper, controlled and prospective studies. Breastfeeding and the late introduction of solid foods (>4 months) is associated with a reduced risk of food allergy, atopic dermatitis, and recurrent wheezing and asthma in early childhood. In all infants....... Preventive dietary restrictions after the age of 4-6 months are not scientifically documented....
Traditionally, the healthcare industry has been no stranger to some conflicts of interest. However, as healthcare responds to demands to contain costs and adapts business models that resemble those of the corporate world, new conflicts of interest arise. Nurse executives operating in healthcare systems today must have an understanding of conflicts of interest in order to promptly identify actual as well as potential conflicts. It is imperative that strategies are set in place to prevent or handle conflicts of interest as they occur in order to build trusting relationships with patients, suppliers, and communities.
Mikkelsen, Elisabeth Naima; Clegg, Stewart
from a more reflexive approach and advance our understanding of conflict. In this essay, we emphasize how philosophical and political assumptions about conflict frame knowledge production within the field and we encourage future theory development to build on different notions of conflict to become......Diverse and often unacknowledged assumptions underlie organizational conflict research. In this essay, we identify distinct ways of conceptualizing conflict in the theoretical domain of organizational conflict with the aim of setting a new critical agenda for reflexivity in conflict research....... In doing so, we first apply a genealogical approach to study conceptions of conflict, and we find that three distinct and essentially contested conceptions frame studies of conflict at work. Second, we employ two empirical examples of conflict to illustrate how organizational conflict research can benefit...
Ma, Hui; Song, Rongze; Pang, Xu; Wen, Bangchun
Considering the misalignment of gear root circle and base circle and accurate transition curve, an improved mesh stiffness model for healthy gear is proposed, and it is validated by comparison with the finite element method. On the basis of the improved method, a mesh stiffness model for a cracked gear pair is built. Then a finite element model of a cracked gear coupled rotor system in a one-stage reduction gear box is established. The effects of crack depth, width, initial position, and crac...
Taenzler, Dennis; Westerkamp, Meike [Adelphi Research, Berlin (Germany); Supersberger, Nikolaus; Ritthoff, Michael; Bleischwitz, Raimund [Wuppertal Institut (Germany)
The demand for both energetic and non-energetic raw materials has been increasing continuously during the past few decades. Especially during the last few years, the threat of structural shortages of supply or availability came into focus. The discussion is highly controversial, especially in the case of petroleum. This sub-report presents an analysis of the supply situation of energetic and non-energetic raw materials, i.e. petroleum, coal and nuclear fuels on the one hand as well as iron and steel, chromium, nickel, cobalt, aluminium, magnesium, copper, platinum and platinum metals, industrial minerals, boron salts, phosphate, zirconium and zirconium oxide on the other hand. It is important to discuss also regional availability patterns in order to arrive at a regional picture of potential supply risks and resulting conflicts over raw materials as this is the best way to assess the danger of impending conflicts. (orig.)
Wu, Canhui; Wang, Yanzhong
Face-gear drives become the main direction of research for aeronautical drives because of their special advantages. Face-gear machining problems have became to baffle the embedded research for face-gear. The basal coordinate systems of face-gear hobbing were setted up according to the face-gear hobbing theory. The hobbing surface equation of facegear was established by using the equation of pinion tooth surface and matrix for coordinate transform based on the gear geometry and applied theory, then the hobbing tooth surface constrain conditions for dedendum undercutting were analyzed, at the same time, the hobbing nodal points were used to construct the three-dimensional basal worm model of face-gear hob by recurring to the three-dimensional software. Furthermore, the special hob for face-gear machining was designed and manufactured. The exact assembly and machining simulation were finished by using the program development software VC++6.0 and the UG customization function in the light of the face-gear hobbing theory. It validates the hob correctness and gets the gear hobbing program. According to the result of machining simulation, facegear numerical control(NC) hob machining was realized in the four-axis NC machine tool. It improves the cutting efficiency and establishs the base for face-gear grinding.
Shangguan, Wen-Bin; Liu, Xue-Lai; Yin, Yuming; Rakheja, Subhash
A nonlinear torsional model for a driveline system with 4 degrees of freedom is proposed for studying gear rattle if a car is at idle. The time-varying meshing stiffness of geared teeth, gear backlash, and the damping from oil film are included in the model. The dynamic responses of the driveline system, such as clutch angular displacement, meshing force and relative displacement between geared teeth, are calculated using the presented model. The influences of stiffness and damping of a clutch on gear rattle of geared teeth in a generic transmission are investigated. Based on the calculation and analysis results, a design guideline to select clutch's stiffness and damping is developed to reduce gear rattle for a car at idle. Taking a generic driveline system of a passenger car as an example, the developed method is experimentally validated by comparing the baseline clutch and revised clutch, in terms of the measured noise inside engine compartment and cab and vibrations at transmission housing.
Sachidananda H. K.
Full Text Available The main cause of power loss or dissipation of heat in case of meshed gears is due to friction existing between gear tooth mesh and is a major concern in low rotational speed gears, whereas in case of high operating speed the power loss taking place due to compression of air-lubricant mixture (churning losses and windage losses due to aerodynamic trial of air lubricant mixture which controls the total efficiency needs to be considered. Therefore, in order to improve mechanical efficiency it is necessary for gear designer during gear tooth optimization to consider these energy losses. In this research paper the power loss analysis for a tooth-sum of 100 altered by ±4% operating between a specified center distance is considered. The results show that negative altered tooth-sum gearing performs better as compared to standard and positive altered tooth-sum gearing.
Tonny SB Hoedodo
Full Text Available Pela Gandong which is believed by Ambonese for its propitiational value is in fact failed to prevent horizontal conflict that victimized a big number of life and financial damages. However, Wayame villagem is found to survive from those conflicts, and the community of this village, comprising of Islam and Christian religious group, succeeds to maintain harmonious relation. The research aims at, first, describing the perception of Wayamae village community to Pela Gandong in the post-conflict period; second, analyzing the cultural competence of pela Gandong in conflict resolution in the era of technology. This research employed qualitative method, involving in-field data gathering based on official report, digging out information from the resource persons who were directly witnessing the conflict when it occured and other references obtained through Forum Group Discussion (FGD. An analysis was performed to seek answer concerning on how the community of Wayame village viewed Pela Gandong in post-conflict period, how it is – as a local wisdom – maintained in the middle of changing and how Pela Gandong was revitalized. Research showed that Pela Gandong was maintained by involving all elements such as customary community and the government. Pela Gandong grew as the icon of Ambonese society in settling conflicts by raising awareness that they are Eastern people, collectivistic in nature, and place kinship into priority.
Cook, Joseph S., Jr.
This invention comprises a torque drive mechanism utilizing axially translatable, mutually engageable transmission members having mating crown gears, driven and driving members with a three-element drive train being biased together by resilient means or by a fluid actuator system, the apparatus being operable to transmit a precisely controlled degree of torque to a driven member. The apparatus is applicable for use in hand tools and as a replacement for impact torque drivers, torque wrenches, motorized screw drivers, or the like, wherein the applied torque must be precisely controlled or limited. The bevel torque drive includes a drive gear which is axially displaceable and rotatable within cylindrical driver housing, a rotatable intermediate gear, and an output gear. Key rotationally secures displaceable gear with respect to input shaft but permits axial movement therebetween. A thrust bearing is preferably connected to the lower end of shaft for support to reduce play and friction between shaft and a transmission joint disc during rotation of the gear train. Coaxially mounted coiled spring is footed against displaceable gear for biasing the displaceable gear toward and into engagement with the intermediate gear for driving intermediate gear and output gear. Torque control is achieved by the use of straight or spiral beveled gears which are of configurations adapted to withdraw from mutual engagement upon the torque exceeding a predetermined limit. The novel, advantageous features of the invention include the configuration of the mating, crown gear sets and the axially translatable, slidable drive gear. The mechanism is capable of transmitting a high degree of torque within a narrow, compact transmission housing. The compact size and narrow, elongated configuration of the housing is particularly applicable for use in hand tools and in multiple torque driver mechanisms in which it is necessary to drive multiple fasteners which are located in close proximity. Prior
Anne S. Meeussen
Full Text Available The classification of materials into insulators and conductors has been shaken up by the discovery of topological insulators that conduct robustly at the edge but not in the bulk. In mechanics, designating a material as insulating or conducting amounts to asking if it is rigid or floppy. Although mechanical structures that display topological floppy modes have been proposed, they are all vulnerable to global collapse. Here, we design and build mechanical metamaterials that are stable and yet capable of harboring protected edge and bulk modes, analogous to those in electronic topological insulators and Weyl semimetals. To do so, we exploit gear assemblies that, unlike point masses connected by springs, incorporate both translational and rotational degrees of freedom. Global structural stability is achieved by eliminating geometrical frustration of collective gear rotations extending through the assembly. The topological robustness of the mechanical modes makes them appealing across scales from engineered macrostructures to networks of toothed microrotors of potential use in micromachines.
Lockard, David P.; Khorrami, Mehdi, R.; Li, Fei
A hybrid approach is used to investigate the noise generated by a simplified landing gear without small scale parts such as hydraulic lines and fasteners. The Ffowcs Williams and Hawkings equation is used to predict the noise at far-field observer locations from flow data provided by an unsteady computational fluid dynamics calculation. A simulation with 13 million grid points has been completed, and comparisons are made between calculations with different turbulence models. Results indicate that the turbulence model has a profound effect on the levels and character of the unsteadiness. Flow data on solid surfaces and a set of permeable surfaces surrounding the gear have been collected. Noise predictions using the porous surfaces appear to be contaminated by errors caused by large wake fluctuations passing through the surfaces. However, comparisons between predictions using the solid surfaces with the near-field CFD solution are in good agreement giving confidence in the far-field results.
(Shortened version of abstract in article itself) This article describes an algorithm for producing, for any desired resolution and any desired numbers of wheel and pinion teeth, polygonal approximations to the shapes of a pair of cycloidal gears that mesh correctly. An Octave implementation of the algorithm, mostly written in 2014, is included. The Octave implementation contains a (crude, but evidently adequate, at least for reasonable numbers of wheel and pinion teeth) solution of the probl...
MATÍAS DUTRA CETUSIC
Full Text Available The author analyzes the prevailing regulation on the use of force, from the perspective of Article 51 of the UN Charter related to the general prohibition of Article 2.4 UN Charter, with special emphasis on the existing doctrinal conflict due to the interpretive duality of the above-mentioned Article 51 C, offering an approach to the problem. In that regard, the theories that justify unilateral anticipatory modalities in the fightagainst organized terrorism are confronted, in order to eventually findsupport in the customary law of the inherent right to self-defense.
Zakrajsek, James J.; Lewicki, David G.
Results of using vibration-based methods to detect gear tooth fatigue cracks are presented. An experimental test rig was used to fail a number of spur gear specimens through bending fatigue. The gear tooth fatigue crack in each test was initiated through a small notch in the fillet area of a tooth on the gear. The primary purpose of these tests was to verify analytical predictions of fatigue crack propagation direction and rate as a function of gear rim thickness. The vibration signal from a total of three tests was monitored and recorded for gear fault detection research. The damage consisted of complete rim fracture on the two thin rim gears and single tooth fracture on the standard full rim test gear. Vibration-based fault detection methods were applied to the vibration signal both on-line and after the tests were completed. The objectives of this effort were to identify methods capable of detecting the fatigue crack and to determine how far in advance of total failure positive detection was given. Results show that the fault detection methods failed to respond to the fatigue crack prior to complete rim fracture in the thin rim gear tests. In the standard full rim gear test all of the methods responded to the fatigue crack in advance of tooth fracture; however, only three of the methods responded to the fatigue crack in the early stages of crack propagation.
S. V. Myamlin
Full Text Available Purpose. To determine the dynamic qualities of the mainline freight locomotives characterizing the safe motion in tangent and curved track sections at all operational speeds, one needs a whole set of studies, which includes a selection of the design scheme, development of the corresponding mathematical model of the locomotive spatial fluctuations, construction of the computer calculation program, conducting of the theoretical and then experimental studies of the new designs. In this case, one should compare the results with existing designs. One of the necessary conditions for the qualitative improvement of the traction rolling stock is to define the parameters of its running gears. Among the issues related to this problem, an important place is occupied by the task of determining the locomotive dynamic properties on the stage of projection, taking into account the selected technical solutions in the running gear design. Methodology. The mathematical modeling studies are carried out by the numerical integration method of the dynamic loading for the mainline locomotive using the software package «Dynamics of Rail Vehicles » («DYNRAIL». Findings. As a result of research for the improvement of locomotive running gear design it can be seen that the creation of the modern locomotive requires from engineers and scientists the realization of scientific and technical solutions. The solutions enhancing design speed with simultaneous improvement of the traction, braking and dynamic qualities to provide a simple and reliable design, especially the running gear, reducing the costs for maintenance and repair, low initial cost and operating costs for the whole service life, high traction force when starting, which is as close as possible to the ultimate force of adhesion, the ability to work in multiple traction mode and sufficient design speed. Practical Value. The generalization of theoretical, scientific and methodological, experimental studies aimed
Guo, Yi; Eritenel, Tugan; Ericson, Tristan M.; Parker, Robert G.
This work developed a computational process to predict noise radiation from gearboxes. It developed a system-level vibro-acoustic model of an actual gearbox, including gears, bearings, shafts, and housing structure, and compared the results to experiments. The meshing action of gear teeth causes vibrations to propagate through shafts and bearings to the housing radiating noise. The vibration excitation from the gear mesh and the system response were predicted using finite element and lumped-parameter models. From these results, the radiated noise was calculated using a boundary element model of the housing. Experimental vibration and noise measurements from the gearbox confirmed the computational predictions. The developed tool was used to investigate the influence of standard rolling element and modified journal bearings on gearbox radiated noise.
Pedersen, Niels Leergaard
Bending stress plays a significant role in gear design wherein its magnitude is controlled by the nominal bending stress and the stress concentration due to the geometrical shape. The bending stress is indirectly related to shape changes made to the cutting tool. This work shows that the bending...... are not very sensitive to small design changes. This observation suggests the use of two new standard cutting tools. © 2010 Elsevier Ltd. All rights reserved....... stress can be reduced significantly by using asymmetric gear teeth and by shape optimizing the gear through changes made to the tool geometry. However, to obtain the largest possible stress reduction a custom tool must be designed depending on the number of teeth, but the stress reductions found...
The main purpose of this paper is to determine the impact of both International Humanitarian Law and anti-piracy International Law on Constitutional Law. International Law is endowed with a rich set of norms on the protection of private individuals in armed conflicts and copes with the diachronic crime of maritime piracy, which may be considered as a private war in the high seas. Constitutional Law has been traditionally geared at two generations of fundamental rights. The paper will aim at a...
Recently scholars around the globe have given attention to conflict prevention, management and resolution. A considerable body of literature has been added to our academic libraries mostly by scholars from the Western societies. Conflicts in the developing areas by contrast are only minimally researched. For quite some ...
Pedro Javier Gamez-Montero
Full Text Available The trochoidal-gear technology has been growing in groundbreaking fields. Forthcoming applications are demanding to this technology a step forward in the conceiving stage of positive displacement machines. The compendium of the qualities and the inherent characteristics of trochoidal-gear technology, especially towards the gerotor pump, together with scale/size factor and magnetic-driven transmission has led to the idea of a magnet-sleeve-sealed variable flow mini trochoidal-gear pump. From its original concept, to the last phase of the design development, the proof of concept, this new product will intend to overcome problems such as noise, vibration, maintenance, materials, and dimensions. The paper aims to show the technological path followed from the concept, design, and model, to the manufacture of the first prototype, where the theoretical and numerical approaches are not always directly reflected in the prototype performance results. Early in the design process, from a standard-commercial sintered metal mini trochoidal-gear unit, fundamental characteristics and dimensional limitations have been evaluated becoming the strategic parameters that led to its configuration. The main technical challenge to confront is being sealed with non-exterior driveshaft, ensuring that the whole interior is filled and wetted with working fluid and helping the hydrodynamic film formation, the pumping effect, and the heat dissipation. Subsequently, the mini pump architecture, embodiment, methodology, materials, and manufacture are presented. The trend of applications of polymer composite materials and their benefits wanted to be examined with this new mini pump prototype, and a pure polyoxymethylene mini trochoidal-gear set has been designed and manufactured. Finally, both the sintered and the polymer trochoidal-gear units have been experimentally tested in an in-house full-instrumented mini test bench. Although the main goal of the presented work is the
Ago, N.D.; Tafida, A.A.
The importance of fishing gear in fishing cannot be over-emphasized; as without it fish cannot be obtained. The method used to catch fish affects the condition in which the product is landed. This means that a bad-catching method would produced bad fish to the consumer. To achieve the goal of self-sufficiency in fish production in Nigeria, there is need to address the lingering problems of fishing gear and craft technology, especially in terms of availability of materials and their cost. The ...
Koulin, G.; Reavie, T.; Frazer, R. C.; Shaw, B. A.
Typically the quality of a gear pair is assessed based on simplified geometric tolerances which do not always correlate with functional performance. In order to identify and quantify functional performance based parameters, further development of the gear measurement approach is required. Methodology for interpolation of the full active helical gear flank surface, from sparse line measurements, is presented. The method seeks to identify the minimum number of line measurements required to sufficiently characterise an active gear flank. In the form ground gear example presented, a single helix and three profile line measurements was considered to be acceptable. The resulting surfaces can be used to simulate the meshing engagement of a gear pair and therefore provide insight into functional performance based parameters. Therefore the assessment of the quality can be based on the predicted performance in the context of an application.
Jørgensen, Frank Thorleif; Andersen, Torben Ole; Rasmussen, Peter Omand
This paper presents calculation and measurement results of a high-performance permanent-magnetic gear. The analyzed permanent-magnetic gear has a gear ratio of 5.5 and is able to deliver 27 N/spl middot/m. The analysis has shown that special attention needs to be paid to the system where the gear...... is to be installed because of a low natural torsion spring constant. The analyzed gear was also constructed in practice in order to validate the analysis and predict the efficiency. The measured torque from the magnetic gear was only 16 N/spl middot/m reduced by the large end-effects. A systematic analysis...
Full Text Available Hydraulic gear pumps are used in many machines and devices. In hydraulic systems of machines gear pumps are main component ofsupply unit or perform auxiliary function. Gear pumps opposite to vane pumps are less complicated. They consists of such components as:housing, gear wheels, bearings, shaft, seal for rotation motion which are not very sensitive for damage and that is why they are using veryoften. However, gear pumps are break down from time to time. Usually damage of pump cause shutting down of machines and devices.One of the way for identifying potential failures and foreseeing their effects is a quality method. On the basis of these methods apreventing action might be undertaken before failure appear. In this paper potential failures and damages of a gear pump were presented bythe usage of matrix FMEA analysis.
Grzegorz WOJNAR; Bogusław ŁAZARZ; Henryk MADEJ
This paper presents results of laboratory tests that were aimed at detecting early stages of various faults in toothed wheels by measurement and analysis of transverse vibration speed of the transmission gear shafts. In experimental investigation, cracking of the root tooth and chipping of the tooth were detected. The laser vibrometer Ometron VH300+ was used for non-contact measurement of shaft transversal vibration speed. Gear vibrations were recorded in selected points of gear housing and g...
The project of CHP2000 type progressive gear has been presented in the article. The offered solution from its construction point of view differs from the existing solutions due to the application of Belleville springs packets supporting the braking roller cam and achieving a flexible range of the gear loading. The standard concept of the gear loading within a mathematical and a geometrical model has been presented in the article. The proposed solution can be used in the friction lifts with th...
Full Text Available Wolf and dog depredation on livestock in the province of Rieti, central Italy, in 2007-2008, was studied. The study area was characterized by a high degree of human disturbance, widespread presence of free ranging dogs and a recent wolf recolonization. Because of the ineffectiveness of compensation programmes, it was not possible to use the official statistics to investigate the extent of the conflict, but sample interviews and surveys of farmers were used. Also, the farming protection tecniques adopted for different livestock species were analysed; the most utilized husbandry method was stabling for cattle and pigs, annual fenced grazing for horses and sheeps, and annual open grazing only for goats. Although sheep farms were the most attacked because of their availability (33.6% of the whole farms, goat farms were the most selected by predators because of their accessibility (40% of farms kept goats in annual open grazing. Management implications to mitigate livestock depredation were discussed.
Scientific progress results from conflicts about the existence of new phenomena. Two theorems are formulated: Whatever is predicted by a sufficiently famous theorist will be discovered independently of whether it exists or not. Thus the criterion for existence of a phenomenon is not its discovery but rather its reproducibility! Whatever is "discovered" by a sufficiently famous experimentalist will be explained independently of its existence. Thus the criterion for understanding a phenomenon is not an explanation but rather the unanimous acceptance of one single explanation. It is argued that the optimal intention of scientists is to be critical but not rigid and at the same time open but not credulous. Since the intentions "open" and "critical" are in opposition, the historical path of science often oscillates between the two extremes "credulous" and "rigid". This is demonstrated by historical examples and applied to the special case of water.
Without healthy conflict management skills, conflict can often escalate or intensify over time. This fact sheet gives tips on utilizing key negotiation skills to help individuals effectively address and cope with conflict and potentially build stronger relationships with others.
Pondy, Louis R.
The viewpoints and findings of the seven empirical studies of organizational conflict contained in this issue are compared and contrasted. A distinction is made between conflict within a stable organization structure and conflict aimed at changing the organization structure. (Author)
... Design and Construction Landing Gear § 23.729 Landing gear extension and retraction system. (a) General. For airplanes with retractable landing gear, the following apply: (1) Each landing gear retracting... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing gear extension and retraction...
Full Text Available This paper presents results of laboratory tests that were aimed at detecting early stages of various faults in toothed wheels by measurement and analysis of transverse vibration speed of the transmission gear shafts. In experimental investigation, cracking of the root tooth and chipping of the tooth were detected. The laser vibrometer Ometron VH300+ was used for non-contact measurement of shaft transversal vibration speed. Gear vibrations were recorded in selected points of gear housing and gear shafts at different speeds and gear loads. Results were analyzed and compared but in this paper is presented only selected examples. This paper shows that on the basis of the transverse vibration speed of transmission gear shafts, it is possible to detect defects at an earlier stage than on the basis of the housing vibration accelerations. In the case of measuring gear shaft vibration velocity, the way of the signal generated by the defect of a gear wheel (or bearing is shortened as well as the influence of composed transmittance of the bearing-gear housing system is eliminated. WV time-frequency analysis and complex continuous wavelet transformations were used for detection. The authors introduced a measure of local tooth damage, which was proportional to the size of damage. The results of research presented in this paperconfirmed that the defect's measure is very sensitive to the development of teeth faults.
G -5 0 Li fe (M c yc le s) P/M Gears Ausform Finished P/M Gears Wrought Steel Gears PC Surface Durability Tests at 304 ksi • Bending fatigue...and scoring resistance tests described in later sections. Mate gears, design shown in Figure 28, were made of wrought AISI -8620 steel using a...at 304 ksi contact stress, and one each at 320 ksi and 335 ksi. The seven tests at 304 ksi all resulted in pitting failures, with life to failure
Worm gears are special gears that resemble screws, and can be used to drive other gears. Worm gears, enable two non-touching shafts in a machine to mesh (join) together. This publication, unique in that it combines both theoretical and practical design aspects, including the latest results of research and development, provides detailed treatment of the theory and production of worm drives, as well as the overarching subject of production geometry of helicoidal surfaces.Included are mathematical models for a number of practical applications; a description of dressing equipment r
A practical workplace guide to handling conflict effectively. Managing employees and encouraging them to work together toward a common goal is an essential skill that all leaders should possess. Conflict Resolution at Work For Dummies provides the tools and advice you need to restore peace, train your colleagues to get along better with others, prevent conflicts from ever starting, and maintain better productivity while boosting morale.: One of the only trade publications that takes the manager's perspective on how to address conflicts, resolve disputes, and restore peace and productivity to t
A. V. Krivosheya
Full Text Available The article deals with the method of finishing the cylindrical gears with diamond worm gear in mechanical engineering on a wide-universal milling machine. For processing, a special device has been developed, which provides for elastic coupling in a tool-detail pair. Diamond tools with different grain parameters, which are used in processing, have been developed and manufactured. As a criterion for evaluating the treatment of gears, roughness parameters were used, which were measured before and after treatment. The measurements were made, both along the profile and along the tooth line of the treated gear. During the work, dynamometers, profilometer, barbell gauge, normalizer were used. For the statistical evaluation of the data obtained, distribution curves were constructed. As a result of research on tooth gearing of gear teeth surfaces, rational parameters of granularity of diamond hone, processing modes, as well as the processing scheme are established.
The concept of conflict, being an outcome of behaviours, is an integral part of human life. Wherever there is a difference of opinion there are chances of conflict. Managing conflict effectively demands multifarious professional abilities and acumen. To resolve and manage conflict, the organisations must understand the causes, theories, approaches and strategies of conflict management. Conflict and stress are interlinked as they are dependent on each other. It is a psychological phenomenon th...
Book Title: Searching for Peace in Africa: An Overview of Conflict Prevention and Management Activities (1999). Book Authors: Monique Mekenkamp, Paul van Tongeren and Hans van de Veen (eds). Utrecht: European Platform for Conflict Prevention and Transformation. 528 pp.
Full Text Available The article describes new method and device for continuously variable speed change management via compound epicyclic gearing with composite planet gears and closed circuit hydrosystem, when the speed control element is either outer ring gear (annulus or the carrier or sun gear. In each case, the control element connected to closed circuit hydrosystem and can be in motion or immovable depending on the bandwidth of hydrosystem’s regulating throttle. We had held theoretical research and received graphic dependences between velocities of driving, control and driven elements by means of computer programing.
Full Text Available Characteristic conceptual solutions of connection of electric motor and gear unit, in the frame of universal motor gear reducer with helical gears, are analyzed in this paper. The aim of this analysis is to highlight the importance and benefits of particular solutions. It is known that today almost all major manufacturers of universal motor gear reducer use special (reducer motors. Smaller manufacturers commonly use standard (IEC motors, although large manufacturers, sometimes, also use IEC motors, especially when the customer request. The both of electric motors have certain advantages which manufacturers of motor reducer, with suitable construction solutions, want to use in order to achieve some benefits in the market.
Azizi, Emanuel; Roberts, Thomas J
A fundamental feature of pennate muscles is that muscle fibers are oriented at an angle to the line of action and rotate as they shorten, becoming more oblique throughout a contraction. This change in fiber orientation (pennation angle) can amplify the shortening velocity of a fiber and increase output velocity of the muscle. The velocity advantage resulting from dynamic changes in pennation angle can be characterized as a gear ratio (muscle velocity/fiber velocity). A recent study has shown that a pennate muscle's gear ratio varies automatically depending on the load such that a muscle operates with a high gear during rapid contractions and low gear during forceful contractions. We examined whether this variable gearing behavior can be replicated in a pennate array of artificial muscles. We used McKibben type pneumatic actuators, which shorten in tension when filled with compressed gas. Similar to muscle fibers, the actuators expand radially during shortening, a feature thought to be a critical part of the variable gearing mechanism in pennate muscles. We arranged McKibben actuators in an array oriented to mimic a pennate muscle, and quantified the system's gear ratio during contraction against a range of loads. Video was used to measure the gear ratio during each contraction. We find that similar to pennate muscles, the gear ratio decreases significantly with increasing load and that variable gearing results from load-dependent variation in the amount of actuator rotation. These results support the idea that variable gearing in pennate muscles is mediated by difference is fiber rotation and the direction of muscle bulging. The behavior of our artificial muscle array also highlights the potential benefits of bio-inspired architectures in artificial muscle arrays, including the ability to vary force and speed automatically in response to variable loading conditions.
Azizi, Emanuel; Roberts, Thomas J.
A fundamental feature of pennate muscles is that muscle fibers are oriented at an angle to the line of action and rotate as they shorten, becoming more oblique throughout a contraction. This change in fiber orientation (pennation angle) can amplify the shortening velocity of a fiber and increase output velocity of the muscle. The velocity advantage resulting from dynamic changes in pennation angle can be characterized as a gear ratio (muscle velocity/fiber velocity). A recent study has shown that a pennate muscle’s gear ratio varies automatically depending on the load such that a muscle operates with a high gear during rapid contractions and low gear during forceful contractions. We examined whether this variable gearing behavior can be replicated in a pennate array of artificial muscles. We used McKibben type pneumatic actuators, which shorten in tension when filled with compressed gas. Similar to muscle fibers, the actuators expand radially during shortening, a feature thought to be a critical part of the variable gearing mechanism in pennate muscles. We arranged McKibben actuators in an array oriented to mimic a pennate muscle, and quantified the system’s gear ratio during contraction against a range of loads. Video was used to measure the gear ratio during each contraction. We find that similar to pennate muscles, the gear ratio decreases significantly with increasing load and that variable gearing results from load-dependent variation in the amount of actuator rotation. These results support the idea that variable gearing in pennate muscles is mediated by difference is fiber rotation and the direction of muscle bulging. The behavior of our artificial muscle array also highlights the potential benefits of bio-inspired architectures in artificial muscle arrays, including the ability to vary force and speed automatically in response to variable loading conditions. PMID:23462288
Azizi, Emanuel; Roberts, Thomas J
A fundamental feature of pennate muscles is that muscle fibers are oriented at an angle to the line of action and rotate as they shorten, becoming more oblique throughout a contraction. This change in fiber orientation (pennation angle) can amplify the shortening velocity of a fiber and increase output velocity of the muscle. The velocity advantage resulting from dynamic changes in pennation angle can be characterized as a gear ratio (muscle velocity/fiber velocity). A recent study has shown that a pennate muscle's gear ratio varies automatically depending on the load such that a muscle operates with a high gear during rapid contractions and low gear during forceful contractions. We examined whether this variable gearing behavior can be replicated in a pennate array of artificial muscles. We used McKibben type pneumatic actuators, which shorten in tension when filled with compressed gas. Similar to muscle fibers, the actuators expand radially during shortening, a feature thought to be a critical part of the variable gearing mechanism in pennate muscles. We arranged McKibben actuators in an array oriented to mimic a pennate muscle, and quantified the system's gear ratio during contraction against a range of loads. Video was used to measure the gear ratio during each contraction. We find that similar to pennate muscles, the gear ratio decreases significantly with increasing load and that variable gearing results from load-dependent variation in the amount of actuator rotation. These results support the idea that variable gearing in pennate muscles is mediated by difference is fiber rotation and the direction of muscle bulging. The behavior of our artificial muscle array also highlights the potential benefits of bio-inspired architectures in artificial muscle arrays, including the ability to vary force and speed automatically in response to variable loading conditions. (paper)
... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Conflicts of interest. 302.17... GENERAL TERMS AND CONDITIONS FOR INVESTMENT ASSISTANCE § 302.17 Conflicts of interest. (a) General. It is EDA's and the Department's policy to maintain the highest standards of conduct to prevent conflicts of...
Yana A. Sadovnikova
Full Text Available The article is devoted to the use of jokes as one of the verbal means of deintensification of confrontation. The examples from modern English works of art illustrating the use of jokes at different stages of the conflict are presented. As a rule, a joke can be used in open and post-conflict phases, the latent phase of the conflict is not expressed. The use of jokes on the open stage of the conflict can create a kind of tipping point to change the course of the conflict, and thereby help to resolve it. On the post-conflict stage, a joke helps to build relationships that can be important preventing renewed conflict. The article draws attention to the combination of other means of deintensification confrontation with a joke to achieve the best result in the conflict settlement process. The verbal means can be referred to the apology and change of subject, non-verbal gestures and kisses, para-verbal — soothing tone. All of these funds, if used in conjunction with a joke, contribute to a successful resolution of the conflict. They can also enhance the effect of the joke, which is especially important in the case of non-verbal means. The author notes that the effectiveness of the joke depends on both sides — how well one of the interviewees apply the tool and how the second would take it. In the case of a failed joke, the conflict is likely to increase.
Silvia Christina Madrid Finck
Full Text Available This article reports on the partnership between the Group of Studies and Research in School Physical Education and Teacher Training (Gepefe/UEPG/CNPq affiliated with the Graduate Program in Education (UEPG/PR, and the Nucleus of Studies and Teacher Training in Peace and Coexistence Education (NEP/UEPG. This partnership has contributed to the creation of the research line ‘Physical Education, Sport and Education for Peace: conceptual, methodological and teacher training dimensions’ in Gepefe. The goal of this article is to present more specific ideas for a convergence between the educational perspectives in sport and school physical education, mediated by the issue of teacher training. When considering aspects present in the discussion on the education for peace (coexistence, conflict, violence and peace, we find specifics to consider actions in teacher training. This process emerges as Brazil is experiencing a special moment in sports, with international events planned for the coming years, thereby expanding the need for thematic reflections regarding violence and coexistence in sports. This leads to reflections on the fundamental role of sports education in forming values of coexistence and debating teacher training in physical education for that reality.
A Composite Skid Landing Gear Design investigation has been conducted. Limit Drop Test as per Federal Aviation Regulations (FAR) Part 27.725 and Crash test as per MIL STD 1290A (AV) were simulated using ABAQUS to evaluate performance of multiple composite fiber-matrix systems. Load factor developed during multiple landing scenarios and energy dissipated during crash were computed. Strength and stiffness based constraints were imposed. Tsai-Wu and LaRC04 physics based failure criteria were used for limit loads. Hashin's damage initiation criteria with Davila-Camanho's energy based damage evolution damage evolution law were used for crash. Initial results indicate that all single-composite skid landing gear may no be feasible due to strength concerns in the cross member bends. Hybridization of multiple composites with elasto-plastic aluminum 7075 showed proof of strength under limit loads. Laminate tailoring for load factor optimization under limit loads was done by parameterization of a single variable fiber orientation angle for multiple laminate families. Tsai-Wu failure criterion was used to impose strength contraints. A quasi-isotropic N = 4 (pi/4) 48 ply IM7/8552 laminate was shown to be the optimal solution with a load failure will be initiated as matrix cracking under compression and fiber kinking under in-plane shear and longitudinal compression. All failures under limit loads being reported in the metal-composite hybrid joint region, the joint was simulated by adhesive bonding and filament winding, separately. Simply adhesive bonding the metal and composite regions does not meet strength requirements. A filament wound metal-composite joint shows proof of strength. Filament wound bolted metal-composite joint shows proof of strength. Filament wound composite bolted to metal cross member radii is the final joining methodology. Finally, crash analysis was conducted as per requirements from MIL STD 1290A (AV). Crash at 42 ft/sec with 1 design gross weight (DGW
Prenzel, Paula V., E-mail: firstname.lastname@example.org; Vanclay, Frank, E-mail: email@example.com
The potential for conflict is omnipresent in all projects, and even in all human interactions, and conflict itself leads to many second-order social impacts. This article examines the contribution of the methodological approach used in social impact assessment (SIA) to conflict management. We view conflict as a process that has its own dynamic, and is to be expected in all situations. By using game theory (prisoner's dilemma), we describe and conceptualize this process and highlight the importance of communication in managing conflict. We demonstrate the potential use of SIA in preventing, managing and resolving conflict. Emphasis is placed on the participatory character of SIA and the role of public media. In contrast to existing literature, our focus is not restricted to the typical fields of study of SIA (e.g. environmental conflicts), but understands conflict itself as a field of application. In this sense, conflict-sensitive SIA can be understood both as an extension to the SIA tool kit and a broadening of the scope of SIA application. -- Highlights: • Conflict is omnipresent and creates both positive and negative social impacts. • Conflict itself represents a possible field of application for SIA. • Conflict escalation is a process that can be modeled in a game-theoretic framework. • There needs to be concerted effort to prevent escalation to avoid harmful outcomes. • Conflict-sensitive SIA can support conflict management and sustainable resolution.
Prenzel, Paula V.; Vanclay, Frank
The potential for conflict is omnipresent in all projects, and even in all human interactions, and conflict itself leads to many second-order social impacts. This article examines the contribution of the methodological approach used in social impact assessment (SIA) to conflict management. We view conflict as a process that has its own dynamic, and is to be expected in all situations. By using game theory (prisoner's dilemma), we describe and conceptualize this process and highlight the importance of communication in managing conflict. We demonstrate the potential use of SIA in preventing, managing and resolving conflict. Emphasis is placed on the participatory character of SIA and the role of public media. In contrast to existing literature, our focus is not restricted to the typical fields of study of SIA (e.g. environmental conflicts), but understands conflict itself as a field of application. In this sense, conflict-sensitive SIA can be understood both as an extension to the SIA tool kit and a broadening of the scope of SIA application. -- Highlights: • Conflict is omnipresent and creates both positive and negative social impacts. • Conflict itself represents a possible field of application for SIA. • Conflict escalation is a process that can be modeled in a game-theoretic framework. • There needs to be concerted effort to prevent escalation to avoid harmful outcomes. • Conflict-sensitive SIA can support conflict management and sustainable resolution
Magalhaes, L. [Departamento de Engenharia Mecanica, Instituto Superior de Engenharia, Instituto Politecnico do Porto (Portugal); Seabra, J. [Porto Univ. (Portugal). Dept. Engenharia Mecanica e Gestao Industrial
This paper enhances actual knowledge of the properties of austempered ductile iron (ADI) as a gear material. Results from scuffing tests performed with ADI gears on a FZG test rig are presented and discussed. Contact condition analysis is done using elast-hydrodynamic theory along with several experimental techniques, as surface electronic scanning microscopy, metallurgical spectroscopy and lubricant ferrographic analysis. (orig.)
... on the lake throughout the study period. All the boats were manually operated by paddling. The prohibition of gura and bamboo traps as fishing gears is recommended because they catch the largest number of small fishes which often are not returned back to the lake. Keywords: Study, fishing gears, Oyan Lake, Nigeria ...
Full Text Available In order to research the vibroimpact characteristics of a planetary gear transmission system under high speed and lightly loaded conditions, a new modeling method is proposed. In the modeling process, linear spring was used to simulate gear mesh elasticity under heavy load cases, and Hertz contact theory was used to calculate the contact force of gear pair under light load cases. Then, effects of the working conditions on the system vibroimpact characteristics are analyzed. The results show that, with input speed growing, the mesh force produced obvious fluctuations on the resonance frequencies of the sun gear and carrier torsion vibration, ring gear’s transverse vibration under the heavy load. Under light load condition, the collision vibration occurs in the gear pair; the changing trend of the contact force shows strongly nonlinear characteristics. The time of mesh-apart in gears pair decreases gradually as the load is increased; until it reaches collision vibration threshold value, the gear pair is no longer mesh-apart. With increasing of the input speed, the time of mesh-apart is decreased gradually; the fluctuation amplitude of contact force shows a linearly increasing trend. The study provides useful theoretical guideline for planetary gear transmission low-noise design.
... 46 Shipping 4 2010-10-01 2010-10-01 false Instructions for changing steering gear. 108.641 Section 108.641 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING... steering gear. Instructions stating, in order, the different steps to be taken for changing to emergency...
Mikulowski, Grzegorz M.; Holnicki-Szulc, Jan
The objective of this paper is to present an integrated feedback control concept for adaptive landing gears (ALG) and its experimental validation. Aeroplanes are subjected to high dynamic loads as a result of the impact during each landing. Classical landing gears, which are in common use, are designed in accordance with official regulations in a way that ensures the optimal energy dissipation for the critical (maximum) sink speed. The regulations were formulated in order to ensure the functional capability of the landing gears during an emergency landing. However, the landing gears, whose characteristics are optimized for these critical conditions, do not perform well under normal impact conditions. For that situation it is reasonable to introduce a system that would adapt the characteristics of the landing gears according to the sink speed of landing. The considered system assumes adaptation of the damping force generated by the landing gear, which would perform optimally in an emergency situation and would adapt itself for regular landings as well. This research covers the formulation and design of the control algorithms for an adaptive landing gear based on MR fluid, implementation of the algorithms on an FPGA platform and experimental verification on a lab-scale landing gear device. The main challenge of the research was to develop a control methodology that could operate effectively within 50 ms, which is assumed to be the total duration of the phenomenon. The control algorithm proposed in this research was able to control the energy dissipation process on the experimental stand.
Haasnoot, Tim; Kraan, M.L.; Bush, S.R.
This paper focuses on the transition in the Dutch cutter fleet-targeting flatfish, from the conventional beam trawl to the pulse trawl fishing gear. In doing so,we explore the process of gear transition, presenting the challenges that fishers and policy-makers face.The pulse trawl technique
... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Vessel and gear restrictions. 300.130... gear restrictions. (a) Factory vessels. Factory vessels are prohibited from operating in treaty waters... top of the trap that, when removed, will leave an opening no smaller than the throat or entrance of...
In this paper the contact stress in rolling-sliding contact of involute spur gear and the effect of coefficient of friction was analyzed. To achieve this, first, three dimensional involute spur gear pairs were developed in Solid works 2012 Premium and the 3D model was exported to ANSYS workbench 14.5. Next, the analysis was ...
VARIABLE MESH STIFFNESS OF SPUR GEAR TEETH USING. FINITE ELEMENT METHOD. Yonatan Afework and Tamrat Tesfaye. Depaliment of Mechanical Engineering. Addis Ababa University. ABSTRACT. The ohiective of this paper is to determine the variahle mesh s/rJlness of spur gear teeth using the finite element ...
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Steering gear: Foreign tankers... (CONTINUED) PORTS AND WATERWAYS SAFETY NAVIGATION SAFETY REGULATIONS § 164.39 Steering gear: Foreign tankers... building contract, the keel of which is laid or which is at a similar stage of construction on or after...
Shashank Pandey*1, Nikhilesh N. Singh2 & Dr. Prabhat Kumar Sinha3
In this research the differential gears analyzed for vibration effect on whole system to optimize the life of the gears under different frequency in the platform of Ansys-14.0 with help of solid work modelling. In this analysis the gear housing also affected by vibration in casing that surrounds the gear box. The function of gear is to protect and provide a platform for gear transmission. It also provides supports for moving parts and protection from outside environmental condition. The diffe...
To assess the effects of a program for the prevention of political violence on empathy, expression of feelings of anger, and the capacity to define peace-violence. This study used a quasi-experimental design with pretest-posttest repeated measures and a control group. The sample comprised 276 adolescents aged between 15 and 17 years (191 in the experimental group, 85 in the control group; 127 boys and 149 girls). A battery of three assessment instruments was administered before and after the intervention. The aim of the program was to increase sensitivity to the victims of political violence, promote respect for human rights, and prevent violence. The intervention consisted of 10 sessions over 3 months. MANOVA analyses revealed that the program increased participants' capacity of empathy (perspective-taking), anger control in annoying situations, and capacity to define peace-violence. This study has practical educational implications and provides an intervention tool that enhances the development of personality during adolescence and may have a preventive effect on violent behavior. Copyright © 2011 SESPAS. Published by Elsevier España. All rights reserved.
Dau, Brynie Kaplan; Gilardi, Kirsten V K; Gulland, Frances M; Higgins, Ali; Holcomb, Jay B; Leger, Judy St; Ziccardi, Michael H
We reviewed medical records from select wildlife rehabilitation facilities in California to determine the prevalence of injury in California Brown Pelicans (Pelecanus occidentalis), gulls (Larus spp.), and pinniped species (Zalophus californianus, Mirounga angustirostris, and Phoca vitulina) due to fishing gear entanglement and ingestion from 2001 to 2006. Of 9,668 Brown Pelican, gull, and pinniped cases described during the 6-yr study period (2001-06), 1,090 (11.3%) were fishing gear-related. Pelican injuries caused by fishing gear were most common in the Monterey Bay region, where 59.6% of the pelicans rescued in this area and admitted to a rehabilitation center were injured by fishing gear over the 6-yr period. The highest prevalence of fishing gear-related injury in gulls was documented in the Los Angeles/Orange County region (16.1%), whereas the highest prevalences in pinnipeds were seen in the San Diego region (3.7%). Despite these higher prevalences of gull and pinniped fishing gear-related injuries in these specific regions, there was no statistical significance in these trends. Juvenile gulls and pinnipeds were more commonly injured by fishing gear than adults (gulls: P = 0.03, odds ratio = 1.29; pinnipeds: P = 0.01, odds ratio = 2.07). Male pinnipeds were twice as likely to be injured by fishing gear as females (P rehabilitated and released (percentage of cases successfully rehabilitated to the point of release out of the total number of fishing gear-related injury cases) was high in all three species groups (pelicans: 63%; gulls: 54%; pinnipeds: 70%). Fishing gear-related injuries in Brown Pelicans and gulls were highest in the fall, but there was only a significant difference between seasons for fishing gear-related injuries in pelicans. Fishing gear-related injuries in pinnipeds most commonly occurred in summer; however, a statistical difference was not detected between seasons for pinnipeds. Derelict fishing gear-lost, abandoned or discarded sport and
Katica (Stevanović Hedrih
Full Text Available A theoretical model of multistep gear transmission dynamics is presented. This model is based on the assumption that the connection between the teeth of the gears is with properties within the range from ideal clasic to viscoelastic so that a new model of connection between the teeth was expressed by means of derivative of fractional order. For this model a two-step gear transmision with three degrees of freedom of motion has been used. The obtained solutions are in the analytic form of the expansion according to time. As boundary cases this model gives results for the case of ideally elastic connection of the gear teeth and for the case of viscoelastic connection of the gear teeth, as well. Eigen fractional modes are obtained and a vizualization is done.
Khabou, M. T.; Bouchaala, N.; Chaari, F.; Fakhfakh, T.; Haddar, M.
In this paper the dynamic behavior of a single stage spur gear reducer in transient regime is studied. Dynamic response of the single stage spur gear reducer is investigated at different rotating velocities. First, gear excitation is induced by the motor torque and load variation in addition to the fluctuation of meshing stiffness due to the variation of input rotational speed. Then, the dynamic response is computed using the Newmark method. After that, a parameter study is made on spur gear powered in the first place by an electric motor and in the second place by four strokes four cylinders diesel engine. Dynamic responses come to confirm a significant influence of the transient regime on the dynamic behavior of a gear set, particularly in the case of engine acyclism condition.
Wang, Yu; Wu, Zhiheng; Duan, Xianyun; Tong, Jigang; Li, Ping; Chen, min; Lin, Qinglin
In order to solve such problems as low efficiency, low quality and instability of gear surface defect detection, we designed a detection system based on machine vision, sensor coupling. By multisensory coupling, and then CCD camera image collection of gear products, using VS2010 to cooperate with Halcon library for a series of analysis and processing of images. At last, the results are fed back to the control end, and the rejected device is removed to the collecting box. The system has successfully identified defective gear. The test results show that this system can identify and eliminate the defects gear quickly and efficiently. It has reached the requirement of gear product defect detection line automation and has a certain application value.
Wu, Qing; Cole, Colin; Luo, Shihui; Spiryagin, Maksym
Longer and heavier trains mean larger in-train forces and more complicated force patterns. Practical experience indicates that the development of fatigue failure of coupling systems in long heavy trains may differ from conventional understanding. The friction-type draft gears are the most widely used draft gears. The ever developing heavy haul transport environment requires further or new understanding of friction draft gear behaviour and its implications for train dynamics as well as fatigue damage of rolling stock. However, modelling of friction draft gears is a highly nonlinear question. Especially the poor predictability, repeatability and the discontinuity of friction make this task more challenging. This article reviews current techniques in dynamics modelling of friction draft gears to provide a starting point that can be used to improve existing or develop new models to achieve more accurate force amplitude and pattern predictions.
Full Text Available The article reveals the essence of pedagogical and conflict situations between teacher and student. Considered ways of solving and preventing pedagogical and conflict situations in school. Principal reasons of conflict situations are selected, situations of activity, conduct and relations. The receptions of influence of teacher of physical culture are separated on personality of schoolchildren. It is well-proven that the profession of teacher of physical culture supposes possibility of conflict situations.
Litvin, F. L.; Chen, N. X.
This study will demonstrate the importance of application of computer numerically controlled (CNC) machines in generation of gear tooth surfaces with new topology. This topology decreases gear vibration and will extend the gear capacity and service life. A preliminary investigation by a tooth contact analysis (TCA) program has shown that gear tooth surfaces in line contact (for instance, involute helical gears with parallel axes, worm gear drives with cylindrical worms, etc.) are very sensitive to angular errors of misalignment that cause edge contact and an unfavorable shape of transmission errors and vibration. The new topology of gear tooth surfaces is based on the localization of bearing contact, and the synthesis of a predesigned parabolic function of transmission errors that is able to absorb a piecewise linear function of transmission errors caused by gear misalignment. The report will describe the following topics: description of kinematics of CNC machines with six degrees of freedom that can be applied for generation of gear tooth surfaces with new topology. A new method for grinding of gear tooth surfaces by a cone surface or surface of revolution based on application of CNC machines is described. This method provides an optimal approximation of the ground surface to the given one. This method is especially beneficial when undeveloped ruled surfaces are to be ground. Execution of motions of the CNC machine is also described. The solution to this problem can be applied as well for the transfer of machine tool settings from a conventional generator to the CNC machine. The developed theory required the derivation of a modified equation of meshing based on application of the concept of space curves, space curves represented on surfaces, geodesic curvature, surface torsion, etc. Condensed information on these topics of differential geometry is provided as well.
Anthony P. Johnson
The premise of this paper is the study in the field of conflict andconflict resolution and that conflict and conflict resolution are usefulareas of focus in order to better understand human behavior. Additionally,I will present data that will highlight the notion that conflict is not in itselfa bad thing and that conflict has the capability to be utilized as a vehiclefor understanding the many contradictions that are necessarily present inour efforts to be social beings.
Seybert, A. F.; Wu, T. W.; Wu, X. F.; Oswald, Fred B.
The modal and acoustical analysis of the NASA gear-noise rig is described. Experimental modal analysis techniques were used to determine the modes of vibration of the transmission housing. The resulting modal data were then used in a boundary element method (BEM) analysis to calculate the sound pressure and sound intensity on the surface of the housing as well as the radiation efficiency of each mode. The radiation efficiencies of the transmission housing modes are compared with theoretical results for finite, baffled plates. A method that uses the measured mode shapes and the BEM to predict the effect of simple structural changes on the sound radiation efficiency of the modes of vibration is also described.
The gravest danger facing mankind is that the superpowers have built a complex technological apparatus of nuclear weaponry without thinking through its purpose or control. In a time of crisis nuclear command systems in both the United States and the USSR are likely to pass rapidly from political to highly fragmented military control, making political direction of a nuclear war virtually impossible. The organization and management of nuclear command systems in both peace and war are analyzed, and potential wartime interactions of the Soviet and American control structures are described. Wartime information gathering is identified as the key problem of command and control because the havoc created in communications and data processing by a nuclear war would result in strong decentralizing tendencies with pathological strategy implications. By focusing on how military organizations actually carry out nuclear strategy, the uncertainty and chaos of nuclear war is shown. While there are no absolute guarantees of security in this perilous age, a full understanding of the opportunities and problems of managing nuclear forces may be the best way to prevent disaster
Jørgensen, Frank Thorleif; Andersen, Torben Ole; Rasmussen, Peter Omand
This paper presents calculation and measurement results of a high-performance permanent-magnetic gear. The analyzed permanent-magnetic gear has a gear ratio of 5.5 and is able to deliver 27 N/spl middot/m. The analysis has shown that special attention needs to be paid to the system where the gear...... is to be installed because of a low natural torsion spring constant. The analyzed gear was also constructed in practice in order to validate the analysis and predict the efficiency. The measured torque from the magnetic gear was only 16 N/spl middot/m reduced by the large end-effects. A systematic analysis...... of the loss components in the magnetic gear is also performed in order to figure out why the efficiency for the actual construction was only 81%. A large magnetic loss component originated in the bearings, where an unplanned extra bearing was necessary due to mechanical problems. Without the losses...
Laberge, Kelsen E.; Berkebile, Stephen P.; Handschuh, Robert F.; Roberts, Gary D.
Hybrid composite gear technology is being investigated to increase power density in rotorcraft drive systems. These gears differ from conventional steel gears in that the structural web material is replaced with a lightweight carbon fiber composite. Past studies have focused on performance of this technology under normal operating conditions, however, for this technology to be viable it must also withstand adverse conditions. The study presented here evaluates the performance of hybrid gears under loss-of-lubrication conditions in NASA Glenn Research Centers Contact Fatigue Test Facility. Two experiments are presented using small-scale 3.5 inch (8.9 cm) pitch diameter hybrid gears and compared to a baseline steel gear pair. Results of these tests show that there are limitations to the use of a hexagonal interlock pattern between the steel and composite. There is also evidence that the presence of polymer in the gear during an oil out event has a potential to increase time to failure. Further studies are planned to expand on these initial findings.
Cho, H. Y.; Nam, G. J.; Oh, B. K. [Chungbuk National Univ., Cheongju (Korea, Republic of)
A computer aided design system for spur, helical, bevel and worm gears by using AutoCAD system and its AutoLISP computer language was newly developed in this study. Two methods are available for a designer to draw a gear. The first method needs the gear design parameters such as pressure, module, number of tooth, shaft angle, velocity, materials, etc. When the gear design parameters are inputted, a gear is drawn in AutoCAD system and maximum allowable power and shaft diameter are calculated additionally. The second method calculates all dimensions and gear design parameters to draw a gear when the information such as transmission, reduction ratio, rpm, materials and pressure are inputted. The system includes four programs. Each program is composed of a data input module, a database module, a strength calculation module, a drawing module, a text module and a drawing edit module. In conclusion, the CAD system would be widely used in companies to find the geometric data and manufacturing course.
Lewicki, David G.; Handschuh, Robert F.; Spievak, Lisa E.; Wawrzynek, Paul A.; Ingraffea, Anthony R.
Robust gear designs consider not only crack initiation, but crack propagation trajectories for a fail-safe design. In actual gear operation, the magnitude as well as the position of the force changes as the gear rotates through the mesh. A study to determine the effect of moving gear tooth load on crack propagation predictions was performed. Two-dimensional analysis of an involute spur gear and three-dimensional analysis of a spiral-bevel pinion gear using the finite element method and boundary element method were studied and compared to experiments. A modified theory for predicting gear crack propagation paths based on the criteria of Erdogan and Sih was investigated. Crack simulation based on calculated stress intensity factors and mixed mode crack angle prediction techniques using a simple static analysis in which the tooth load was located at the highest point of single tooth contact was validated. For three-dimensional analysis, however, the analysis was valid only as long as the crack did not approach the contact region on the tooth.
Sørensen, Karsten Engsig
The contribution discuss how the harmonisation in the EU has been directed at either preventing or solving conflicts between shareholders.......The contribution discuss how the harmonisation in the EU has been directed at either preventing or solving conflicts between shareholders....
Antolick, Lance J.; Branning, Jeremy S.; Wade, Daniel R.; Dempsey, Paula J.
The U.S. Army is currently expanding its fleet of Health Usage Monitoring Systems (HUMS) equipped aircraft at significant rates, to now include over 1,000 rotorcraft. Two different on-board HUMS, the Honeywell Modern Signal Processing Unit (MSPU) and the Goodrich Integrated Vehicle Health Management System (IVHMS), are collecting vibration health data on aircraft that include the Apache, Blackhawk, Chinook, and Kiowa Warrior. The objective of this paper is to recommend the most effective gear condition indicators for fleet use based on both a theoretical foundation and field data. Gear diagnostics with better performance will be recommended based on both a theoretical foundation and results of in-fleet use. In order to evaluate the gear condition indicator performance on rotorcraft fleets, results of more than five years of health monitoring for gear faults in the entire HUMS equipped Army helicopter fleet will be presented. More than ten examples of gear faults indicated by the gear CI have been compiled and each reviewed for accuracy. False alarms indications will also be discussed. Performance data from test rigs and seeded fault tests will also be presented. The results of the fleet analysis will be discussed, and a performance metric assigned to each of the competing algorithms. Gear fault diagnostic algorithms that are compliant with ADS-79A will be recommended for future use and development. The performance of gear algorithms used in the commercial units and the effectiveness of the gear CI as a fault identifier will be assessed using the criteria outlined in the standards in ADS-79A-HDBK, an Army handbook that outlines the conversion from Reliability Centered Maintenance to the On-Condition status of Condition Based Maintenance.
Maier, Eugen; Raney, Michael Raymond
A multi-stage internal gear/turbine fuel pump for a vehicle includes a housing having an inlet and an outlet and a motor disposed in the housing. The multi-stage internal gear/turbine fuel pump also includes a shaft extending axially and disposed in the housing. The multi-stage internal gear/turbine fuel pump further includes a plurality of pumping modules disposed axially along the shaft. One of the pumping modules is a turbine pumping module and another of the pumping modules is a gerotor pumping module for rotation by the motor to pump fuel from the inlet to the outlet.
Handschuh, Robert F.
An overview of rotary wing evolution and innovations over the last 20 years was presented. This overview is provided from a drive system perspective. Examples of technology innovations that have changed and advanced drive systems of rotary wing vehicles will be provided. These innovations include full 6-axis CNC gear manufacture, face gear development to aerospace standards, health and usage monitoring, and gear geometry and bearing improvements. Also, an overview of current state-of-the-art activities being conducted at NASA Glenn is presented with a short look to fixed and rotary wing aircraft and systems needed for the future.
Handschuh, Robert F.; Krantz, Timothy L.
A series of bench top experiments was conducted to determine the effects of metallic debris being dragged through meshing gear teeth. A test rig that is typically used to conduct contact fatigue experiments was used for these tests. Several sizes of drill material, shim stock, and pieces of gear teeth were introduced and then driven through the meshing region. The level of torque required to drive the "chip" through the gear mesh was measured. From the data gathered, chip size sufficient to jam the mechanism can be determined.
Full Text Available The project of CHP2000 type progressive gear has been presented in the article. The offered solution from its construction point of view differs from the existing solutions due to the application of Belleville springs packets supporting the braking roller cam and achieving a flexible range of the gear loading. The standard concept of the gear loading within a mathematical and a geometrical model has been presented in the article. The proposed solution can be used in the friction lifts with the loading capacity from 8500 up to 20000 N.
Simon, Valerie A.; Furman, Wyndol
This study examined associations between interparental conflict and adolescents' romantic relationship conflict. High school seniors (N = 183) who lived with married parents completed questionnaires about their parents' marriage and their own romantic relationships. A subset of 88 adolescents was also observed interacting with their romantic…
Organisational conflict manifests in various forms and has differing causative factors. Social factors like inadequate motivation, political interference in labour issues and undue pressure exerted on the organisational structure by employers of labour often cause conflicts in organisations. No wonder Odoh (2006) detailed the.
... 49 Transportation 4 2010-10-01 2010-10-01 false Draw gear between steam locomotive and tender. 230... Steam Locomotives and Tenders Draw Gear and Draft Systems § 230.90 Draw gear between steam locomotive and tender. (a) Maintenance and testing. The draw gear between the steam locomotive and tender...
... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Open access fishery gear identification... COAST STATES West Coast Groundfish-Open Access Fisheries § 660.319 Open access fishery gear identification and marking. (a) Gear identification. (1) Open access fixed gear (longline, trap or pot, set net...
Intervenciones preventivas de la violencia interna en el trabajo: políticas de buenas prácticas y gestión de conflictos Internal violence at work preventive interventions: good practice policies and conflict management
Antonia Bernat Jiménez
that which happens between coworkers, including middle management and high command. It includes physical violence and sexual and psychological harassment, as well as other psychological violent conducts different from that. It must be considered as a psychosocial risk which involves important danger for people's health and safety as well as organizational repercussions through direct and indirect costs. Considering internal violence from the "work risk" point of view means that it should be approached using the preventive action principles while it also allows the adoption of active strategies directed to prevent the phenomenon. Main national and international organizations propose to implement policies to prevent violence in the workplace. This article deals with the convenience of the development and implementation in organizations of an internal violence prevention policy, which involves all the organization, orientated to achieve healthy workplace environments focused on organizational and psychosocial factors. This article approaches the essential premises of internal violence prevention policies, dealing as well with the basic moments of the preventive strategy: - psychosocial risks evaluation - good practice policy - procedures for management of conflicts and psychological harassment at work - organizational communication strategies and formative actions To accomplish actual effectiveness, the internal violence prevention policies must be incorporated to the organization's Prevention Management System, which will at the same time, be integrated in all the rest of the management systems of the company.
Drescher, Christian; Gebser, Martin; Kaufmann, Benjamin; Schaub, Torsten
Modern solvers for Boolean Satisfiability (SAT) and Answer Set Programming (ASP) are based on sophisticated Boolean constraint solving techniques. In both areas, conflict-driven learning and related techniques constitute key features whose application is enabled by conflict analysis. Although various conflict analysis schemes have been proposed, implemented, and studied both theoretically and practically in the SAT area, the heuristic aspects involved in conflict analysis have not yet receive...
Rajeshkumar, S.; Manoharan, R.
In this study, the parametric design and contact analysis of composite spur gears are investigated numerically. Composite gear provides an adequate strength to weight ratio, more hardness, durability and low maintenance cost. It is emerging better alternatives for replacing metallic gears. The finite element model of spur gear is developed with the assistance of the Ansys software. In this study each design factor such has stress distributions, strain and deformation are considered to compare composite gear with steel and polymer gears. An APDL gear model has been developed for the design evaluation and comparison study.
Full Text Available The paper deals with the alternative of determination of state of the belt gear. To realize themeasurements a newly developed device was designed for measurement and diagnostics of the belt gears. The main task is to detect the V-belt slip expressed by the coefficient of elastic creep and of specific slip with a measuring device. The measurements regarding can be performed if input revolutions of the electric motor and torque of the belt gear are constant whereas the tensioning force of the belt gear changes. It is also possible to perform the measurement if the input revolutions of the electric motor and the tensioning forces are constant and the torque changes.
Cetinel, Hakan [Celal Bayar Univ., Mechanical Engineering Dept. (Turkey); Yilmaz, Burak
In this study, trochoidal type (gerotor) hydraulic pump gears were produced by powder metallurgy (P/M) technique. Several gears with different mechanical properties have been obtained by changing process variables. The tooth contact stresses were calculated analytically under particular operation conditions of the hydraulic pump. The 3D models have been obtained from real gears by using Capability Maturity Model (CMM, 3D scanning) operation and SOLIDWORKS software. Stress analyses were conducted on these 3D models by using ANSYS WORKBENCH software. It was found that the density increases by the increase of sintering duration and mechanical properties were positively affected by the increase of density. Maximum deformation takes place in the region of the outer gear where failure generally occurs with the minimum cross-section area.
National Aeronautics and Space Administration — This Phase II SBIR project deals with the design, development, and testing of a "Plasma Fairing" to reduce noise on the Gulfstream G550 landing gear. The plasma...
Wang, P. Y.; Chang, S. L.; Lee, B. Y.; Nguyen, D. H.; Cao, C. W.
Gears are the most important transmission component in machines. The rapid development of the machines in industry requires a shorter time of the analysis process. In traditional, the gears are analyzed by setting up the complete mathematical model firstly, considering the profile of cutter and coordinate systems relationship between the machine and the cutter. It is a really complex and time-consuming process. Recently, the CAD/CAE software is well developed and useful in the mechanical design. In this paper, the Autodesk Inventor® software is introduced to model the spherical gears firstly, and then the models can also be transferred into ANSYS Workbench for the finite element analysis. The proposed process in this paper is helpful to the engineers to speed up the analyzing process of gears in the design stage.
Liu, Huaiju; Zhu, Caichao; Sun, Zhangdong; Zhang, Yuanyuan; Song, Chaosheng
The frictional power loss issue of gear pairs becomes an important concern in both industry and academia due to the requirement of the energy saving and the improvement of power density of gear drives. A thermal starved elastohydrodynamic lubrication model is developed to study the tribological performance of a spur gear pair under starved lubrication conditions. The contact pressure, the film thickness, the temperature rise, the frictional power loss, as well as the coefficient of friction are evaluated by considering the variation of the curvature radius, the sliding/rolling motion, and the load distribution of gear tooth within the meshing period. Effects of lubrication starvation condition, load and speed on the coefficient of friction are studied.
helical gear in mechanical power transmissions. This is because of its advantages in standardization, machining, high efficiency and adaptability to load and center distance. For mechanical power transmission, involving high speed a maximum, ...
... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Operating Limitations and Information Operating... established landing gear extended speed V LE may not exceed the speed at which it is safe to fly with the...
... Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30 percent of its cross-sectional area, cracked, broken, or missing. All pins shall be secured in place with...
Full Text Available Gears transmission can be important sources of vibration in the mechanical system structures and can have a significant share in the overall vibration level. The current trend of significant increase in powers and speeds transmitted by modern mechanical systems, along with the size reduction, may cause a worsening of the behaviour of transmissions with gears in terms of vibration, especially when the optimization criteria were not respected in the design, execution and installation phase. This paper presents a study of vibrations that occur in a double harmonic gear transmission (DHGT, based on experimental research. The experimental researches revealed that in a double harmonic gear transmission the vibrations are initiated and develop in the multipara harmonics engagement of the teeth and in the kinematic couplings materialized between the wave generator and the flexible toothed wheel. These vibrations are later transmitted by means of the shafts and bearings to the transmission housing, respectively, through the walls of it, propagating in the air.
National Aeronautics and Space Administration — Sentient will develop an enhanced prediction of gear tooth surface fatigue life with rigorous analysis of the tribological phenomena that contribute to pitting...
Quirine Eijkman; M. Parlevliet
Hoofdstuk 13 in Handboek Conflict. Titel: Mensenrechten in conflict. Inhoudsopgave: 13.1 Mensenrechten 13.2 Mensenrechtenschendingen als gevolg en oorzaak van conflict 13.3 Mensenrechten in conflictoplossing 13.4 Dilemmas in de praktijk 13.5 Conclusie
The article presents several activities designed to sharpen students' listening and observation skills and help them practice finding and evaluating alternatives to classroom conflicts and conflicts they may encounter elsewhere. Activities include solution skits, role playing, reading and writing conflict stories, and making comic strips. (SM)
Full Text Available Asymmetrical involute gears have a different value of the operating pressure angle for right and left side of the gear. These teeth are suitable for one direction of rotation. Such teeth enable to change the length of the generating line. They enable to improve the value of reduced radii of curvature. Asymmetrical teeth allow reducing the values of Hertz's pressures, especially on the root of the teeth. Hertz pressures are directly related to the asymmetry.
A flightworthy active control landing gear system for a supersonic aircraft was designed to minimize aircraft loads during takeoff, impact, rollout, and taxi. The design consists of hydromechanical modifications to the existing gear and the development of a fail-safe electronic controller. analytical RESULTS INDICATE that for an aircraft sink rate of 0.914 m/sec (3 ft/sec) the system achieves a peak load reduction of 36% during landing impact.
The product range of the rail vehicle industry comprises the construction of railroad material for long-distance and short-distance transport. This includes, for example, locomotives and cars, subway, light railway and tramway cars as well as rail vehicle equipment. The development of the industry is determined by the demand for transport services and government actions for the extension of railways and procurement of suitable vehicle types. In contrast to road vehicles, differential gears are only used in a negligible percentage of rail vehicles. Primarily in the short-distance rail transport sector, the demand for differential gears is growing due to increased drive power, smaller wheel diameters, lower vehicle mass with higher load capacity, the introduction of low-floor technology as well as the requirement of employing ever more quiet vehicles. In hydrostatic self-locking differential gears, oil is supplied to the gears within the differential gearbox. They only rotate relative to each other when the differential gear performs a compensation movement. In this case, oil is transported in the tooth space to the meshing of the gears, where it is displaced due to the meshing and must drain through tight gaps. The pressure generated by this process acts against the compensation movement of the gear, and the drive torque is transmitted to the wheel that has the higher friction. The achievable locking torque is linearly dependent on the differential speed of the drive wheel. This locking effect is achieved without wear-prone components and works automatically without active external intervention. The design space required corresponds to that of conventional differential gears, as the locking effect is integrated in the existing design. (orig.)
Kjærgaard, Peter C.
Darwin-industrien i højt gear. Næste år bliver et 'Darwin-år' - både tilhængere og kritikere gør sig klar. Udgivelsesdato: 12. december......Darwin-industrien i højt gear. Næste år bliver et 'Darwin-år' - både tilhængere og kritikere gør sig klar. Udgivelsesdato: 12. december...
Camelia Elena MUNTEANU
Full Text Available Vertical takeoff, vertical landing (VTVL is a subject of international interest at the moment thanks to the successful recovery of the Blue Origin vehicle. Aggressive weight targets with a short development time in the aerospace and space industry clearly need an integration of advanced computer aided structural optimization methods. Topological optimization is used from the concept phase of a design process development in order to obtain a fundamental design approach. The aim of the article is to determine the principal directions for distribution of the material for a VTVL landing gear within the specified volume in order to obtain the initial design approach. To achieve the maximum performance within the studied component, the result is then refined from a manufacturability point of view. The use of such methods notably reduces the development iterations between the design and stress departments. Thus, the overall time is reduced which translates into a lower overall cost and shorter time development from the concept to the final product.
Delgado, Irebert R.; Dempsey, Paula J.; Antolick, Lance J.; Wade, Daniel R.
This paper details analyses of condition indicator performance for the helicopter nose gearbox within the U.S. Army's Condition-Based Maintenance Program. Ten nose gearbox data sets underwent two specific analyses. A mean condition indicator level analysis was performed where condition indicator performance was based on a 'batting average' measured before and after part replacement. Two specific condition indicators, Diagnostic Algorithm 1 and Sideband Index, were found to perform well for the data sets studied. A condition indicator versus gear wear analysis was also performed, where gear wear photographs and descriptions from Army tear-down analyses were categorized based on ANSI/AGMA 1010-E95 standards. Seven nose gearbox data sets were analyzed and correlated with condition indicators Diagnostic Algorithm 1 and Sideband Index. Both were found to be most responsive to gear wear cases of micropitting and spalling. Input pinion nose gear box condition indicators were found to be more responsive to part replacement during overhaul than their corresponding output gear nose gear box condition indicators.
Recently, Lufkin Industries, Power Transmission Div., full-load tested a high-speed gear designed to couple a 50 Hz electric power generator to a GE LM6000 gas turbine for a power generation project in Australia. The gear is rated 52.2 MW to match the output of the LM6000 gas turbine believed to be one of the largest gear testing operations for this type and size of gear. Each gear drive manufactured by Lufkin is full-speed tested to verify its performance. Tests performed on high-speed units duplicate field conditions, as closely as possible, in order to verify critical speed analysis results and new bearing designs, if used. Lufkin also tests design techniques used in the development of new products. The finite element analysis performed to predict housing deflection in the thrust bearing area of a new extruder driveline was verified by testing of a prototype unit housing. Recently, housing structure stiffness and natural frequencies were predicted and verified on the test stand for some 50 MW vertically offset gear units. A complete data acquisition system is used to gather data from bearing, inlet and drain temperature monitoring points. The temperature monitoring system will accommodate type T,K,J, and E thermocouples and platinum and nickel RTDs.
Qi, Yushi; Du, Zhiming; Sun, Hongsheng; Chen, Lihua; Wang, Changshun
Asymmetric gear has complex structure, so using plastic forming technology to process the gear has problems of large forming load, short die life, bad tooth filling, and so on. To solve these problems, this paper presents a radial warm extrusion process of asymmetric gear to reduce the forming load and improve the filling in the toothed corner portion. Using the new mold and No. 45 steel to conducting forming experiments under the optimal forming parameters: billet temperature is 800°C, mold temperature is 250°C, the forming speed is 30mm/s, and the friction coefficient is 0.15, we can obtain the complete asymmetric gear with better surface and tooth filling. Asymmetric gears’ microstructure analysis and mechanical testing showed that the small grain evenly distributed in the region near the addendum circle with high strength; the area near the central portion of the gear had a coarse grain size, uneven distribution and low strength. Significant metal flow lines at the corner part of the gear indicated that a large number of late-forming metal flowed into the tooth cavity filling the corner portion.
Full Text Available Considering the misalignment of gear root circle and base circle and accurate transition curve, an improved mesh stiffness model for healthy gear is proposed, and it is validated by comparison with the finite element method. On the basis of the improved method, a mesh stiffness model for a cracked gear pair is built. Then a finite element model of a cracked gear coupled rotor system in a one-stage reduction gear box is established. The effects of crack depth, width, initial position, and crack propagation direction on gear mesh stiffness, fault features in time domain and frequency domain, and statistical indicators are investigated. Moreover, fault features are also validated by experiment. The results show that the improved mesh stiffness model is more accurate than the traditional mesh stiffness model. When the tooth root crack appears, distinct impulses are found in time domain vibration responses, and sidebands appear in frequency domain. Amplitudes of all the statistical indicators ascend gradually with the growth of crack depth and width, decrease with the increasing crack initial position angle, and firstly increase and then decrease with the growth of propagation direction angle.
Huanzhi Feng; Wei Liang; Laibin Zhang; Juwei Shi
Gear box is one of the most important transmission components in mechanical systems. Fault diagnosis and state monitoring techniques for gear box have been studied for years. But in practical, gear box usually works under varying work conditions which has not been considered in most studies. In this paper, a novel state monitoring method is proposed for monitor gear box work with varying conditions. The vibration signal is de-nosied by morphological filtering. Then gear-mesh frequency band is...
Deta Rachmat Andika
Full Text Available Seiring perkembangan zaman, teknologi roda gigi dituntut untuk mampu mentransmisikan daya yang besar dengan efisiensi yang besar pula. Pada jenis intersecting shaft gear, tipe roda gigi payung spiral (spiral bevel gear merupakan perkembangan dari roda gigi payung bergigi lurus (straight bevel gear. Kelebihan dari spiral bevel gear antara lain adalah kemampuan transmisi daya dan efisiensi yang lebih besar pada geometri yang sama serta tidak terlalu berisik. Akan tetapi spiral bevel gear juga mempunyai kelemahan jika dibandingkan dengan straight bevel gear. Selain proses manufaktur yang lebih rumit, profil lengkung gigi spiral ini membuat distribusi tegangan yang terjadi menjadi lebih rumit untuk dimodelkan dengan persamaan matematika. Salah satu pendekatan yang dapat dilakukan adalah dengan menggunakan metode elemen hingga. Penelitian diawali dengan membuat model dari straight bevel gear dan juga spiral bevel gear yang sudut spiralnya divariasikan 20, 35, dan 45 derajat. Model dibuat dengan dimensi yang sama baik diameter maupun jumlah gigi gear. Langkah selanjutnya yaitu perhitungan analitis pada straight bevel gear dimana hasilnya akan dibandingkan dengan hasil simulasi statis. Setelah eror yang terjadi dibawah 15% maka dilakukan simulasi dinamis pada semua model yang telah dibuat yaitu straight bevel dan juga spira bevel gear. Hasil yang didapatkan dari penelitian ini adalah secara keseluruhan spiral bevel gear lebih kuat daripada straight bevel gear pada dimensi dan beban yang sama jika dilihat dari lebih kecilnya tegangan bending dan tegangan kontak maksimum yang terjadi. Tegangan terbesar terjadi pada jenis straight bevel gear baik pada tegangan bending maupun tegangan kontak sedangkan spiral bevel gear dengan variasi sudut Seiring spiral 35 mempunyai nilai tegangan terkecil. Prosntase selisih tegangan bending maksimum yang terjadi antara straight bevel gear dan spiral bevel gear dengan variasi sudut spiral 35 derajat sebesar 44
... 46 Shipping 2 2010-10-01 2010-10-01 false Steering-gear control systems. 58.25-70 Section 58.25-70... MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-70 Steering-gear control systems. (a) Each power-driven steering-gear system must be provided with at least one steering-gear control system. (b) The main steering...
Hu Kaixian; Hipel, Keith W.; Fang, Liping
A multi-stage conflict model is developed to analyze international hazardous waste disposal disputes. More specifically, the ongoing toxic waste conflicts are divided into two stages consisting of the dumping prevention and dispute resolution stages. The modeling and analyses, based on the methodology of graph model for conflict resolution (GMCR), are used in both stages in order to grasp the structure and implications of a given conflict from a strategic viewpoint. Furthermore, a specific case study is investigated for the Ivory Coast hazardous waste conflict. In addition to the stability analysis, sensitivity and attitude analyses are conducted to capture various strategic features of this type of complicated dispute.
van Doorn, M.D.
Conflict is an inevitable feature of social relationships. When people interact, disagreements may arise. Especially in close relationships, people sometimes disagree. Although conflict might jeopardize relationships, conflict is not necessarily detrimental. The way conflicts are handled is
Almost, Joan; Doran, Diane M; McGillis Hall, Linda; Spence Laschinger, Heather K
To test a theoretical model linking selected antecedent variables to intra-group conflict among nurses, and subsequently conflict management style, job stress and job satisfaction. A contributing factor to the nursing shortage is job dissatisfaction as a result of conflict among nurses. To develop strategies to reduce conflict, research is needed to understand the causes and outcomes of conflict in nursing work environments. A predictive, non-experimental design was used in a random sample of 277 acute care nurses. Structural equation modelling was used to analyse the hypothesised model. Nurses' core self-evaluations, complexity of care and relationships with managers and nursing colleagues influenced their perceived level of conflict. Conflict management style partially mediated the relationship between conflict and job satisfaction. Job stress had a direct effect on job satisfaction and core self-evaluation had a direct effect on job stress. Conflict and its associated outcomes is a complex process, affected by dispositional, contextual and interpersonal factors. How nurses manage conflict may not prevent the negative effects of conflict, however, learning to manage conflict using collaboration and accommodation may help nurses experience greater job satisfaction. Strategies to manage and reduce conflict include building interactional justice practices and positive interpersonal relationships. © 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd.
Larsen, Sanne Vammen; Hansen, Anne Merrild; Nielsen, Helle
of such conflicts, and the role social impacts play. The paper analyses in depth four cases of renewable energy projects, utilizing a conceptualization of conflict constituted by three elements: Attitude, behavior and contradictions. Through analysis of EIA reports and hearing responses as well as interviews......, the paper digs deeper to nuance what constitutes the conflicts and what role social impacts play.......The transition to renewable energy is currently in many places challenged by conflicts over specific projects. For example siting of onshore wind turbines often causes conflicts with local communities, sometimes leading to abandonment of the project or plan. This paper presents an analysis...
In this volume, Ting-Toomey and Oetzel accomplish two objectives: to explain the culture-based situational conflict model, including the relationship among conflict, ethnicity, and culture; and, second, integrate theory and practice in the discussion of interpersonal conflict in culture, ethnic, and gender contexts. While the book is theoretically directed, it is also a down-to-earth practical book that contains ample examples, conflict dialogues, and critical incidents. Managing Intercultural Conflict Effectively helps to illustrate the complexity of intercultural conflict interactions and readers will gain a broad yet integrative perspective in assessing intercultural conflict situations. The book is a multidisciplinary text that draws from the research work of a variety of disciplines such as cross-cultural psychology, social psychology, sociology, marital and family studies, international management, and communication.
Agger, Annika; Poulsen, Birgitte
forms of institutional design of citizen participation processes, less attention has been paid to the role of public administrators, and their role in facilitating processes of citizen participation. Public administrators have to work with diverse groups of citizens with diverging, and often conflicting......, interests. However, many public administrators have not been adequately exposed to the rationales of conflicts and the skills in resolving conflicts. The aim of this paper is to analyse the different types of conflicts that public administrators experience in formal processes of citizen involvement. Whereas...... the literature of deliberative democracy claims that consensus is most often the result of rational deliberative processes, the claim of this paper is that conflicts is more likely a natural and integrated part of such deliberative acts. Conflicts are, thus, seen as inevitable. Also conflicts may function...
Waite, Roberta; McKinney, Nicole S
Professional nurses are taking on leadership roles of diverse healthcare teams. Development of conflict competence is essential, yet requires self-awareness and deliberate effort. Heightened awareness of one's preferred conflict style and cognizance of the implications of overuse and/or underuse of these styles is important. DESIGN/METHODOLOGICAL APPROACH: A pre-post survey design (N = 14) used paired sample T-test. Paired sample correlations and an overview of the paired sample test are reported. Students gained self-awareness about their preferred conflict style, recognized that each conflict style has its utility depending on any given situation, and demonstrated a difference in their most frequently used style. Limited data conveys conflict behavior styles among pre-licensure nursing; however, students can influence their own environments (either causing or fueling situations) by their personal conflict-handling styles. Early development of these skills can raise awareness and cultivate ease in the management of conflict within varied settings.
... Vessels, based on Area, Gear, and Vessel Type. (See Â§ 679.24(e) for complete seabird avoidance program requirements; see 679.24(e)(1) for applicable fisheries) 20 Table 20 to Part 679 Wildlife and Fisheries FISHERY... Gear Requirements for Vessels, based on Area, Gear, and Vessel Type. (See § 679.24(e) for complete...
G. P. Mojarov
Full Text Available A conflict situation in computer systems CS is the phenomenon arising when the processes have multi-access to the shared resources and none of the involved processes can proceed because of their waiting for the certain resources locked by the other processes which, in turn, are in a similar position. The conflict situation is also called a deadlock that has quite clear impact on the CS state.To find the reduced to practice algorithms to resolve the impasses is of significant applied importance for ensuring information security of computing process and thereupon the presented article is aimed at solving a relevant problem.The gravity of situation depends on the types of processes in a deadlock, types of used resources, number of processes, and a lot of other factors.A disadvantage of the method for preventing the impasses used in many modern operating systems and based on the preliminary planning resources required for the process is obvious - waiting time can be overlong. The preventing method with the process interruption and deallocation of its resources is very specific and a little effective, when there is a set of the polytypic resources requested dynamically. The drawback of another method, to prevent a deadlock by ordering resources, consists in restriction of possible sequences of resource requests.A different way of "struggle" against deadlocks is a prevention of impasses. In the future a prediction of appearing impasses is supposed. There are known methods [1,4,5] to define and prevent conditions under which deadlocks may occur. Thus the preliminary information on what resources a running process can request is used. Before allocating a free resource to the process, a test for a state “safety” condition is provided. The state is "safe" if in the future impasses cannot occur as a result of resource allocation to the process. Otherwise the state is considered to be " hazardous ", and resource allocation is postponed. The obvious
Eigaard, Ole Ritzau; Bastardie, Francois; Breen, Michael
a different approach using the gear itself (design and dimensions) for understanding and estimation of the physical interactions with the seafloor at the individual fishing operation level. With reference to the métier groupings of EU logbooks, we defined 17 distinct towed gear groups in European waters (11...... otter trawl groups, 3 beam trawl groups, 2 demersal seine groups, and 1 dredge group), for which we established seafloor “footprints”. The footprint of a gear was defined as the relative contribution from individual larger gear components, such as the trawl doors, sweeps and ground gear, to the total...... types based on a review of the scientific literature. For each defined gear group a vessel-size (kW or total length) – gear size (total gear width or circumference) relationship was estimated to enable the prediction of gear footprint area and sediment penetration from vessel size. The implications...
Pedersen, Niels Leergaard
by different standards, with the ISO standard probably being the most common one. Gears are manufactured using two principally different tools: rack tools and gear tools. In this work, the bending stress of involute teeth is minimized by shape optimization made directly on the final gear. This optimized shape...... is then used to find the cutting tool (the gear envelope) that can create this optimized gear shape.A simple but sufficiently flexible root parameterization is applied and emphasis is put on the importance of separating the shape parameterization from the finite element analysis of stresses. Large improvements......The strength of a gear is typically defined relative to durability (pitting) and load capacity (tooth-breakage). Tooth-breakage is controlled by the root shape and this gear part can be designed because there is no contact between gear pairs here. The shape of gears is generally defined...
Handschuh, Robert F.; LaBerge, Kelsen E.; DeLuca, Samuel; Pelagalli, Ryan
Hybrid gears have been tested consisting of metallic gear teeth and shafting connected by composite web. Both free vibration and dynamic operation tests were completed at the NASA Glenn Spur Gear Fatigue Test Facility, comparing these hybrid gears to their steel counterparts. The free vibration tests indicated that the natural frequency of the hybrid gear was approximately 800 Hz lower than the steel test gear. The dynamic vibration tests were conducted at five different rotational speeds and three levels of torque in a four square test configuration. The hybrid gears were tested both as fabricated (machined, composite layup, then composite cure) and after regrinding the gear teeth to the required aerospace tolerance. The dynamic vibration tests indicated that the level of vibration for either type of gearing was sensitive to the level of load and rotational speed.
Dijkstra, Hylke; Mahr, Ewa; Petrov, Petar
This report analyses how the EU, UN and OSCE exchange civilian capabilities during crisis missions in Kosovo, Mali and Armenia.......This report analyses how the EU, UN and OSCE exchange civilian capabilities during crisis missions in Kosovo, Mali and Armenia....
... through the chock opening, the leads of preventers to cleats shall be such that the direction of the line... be left slack. (e) Cargo falls. Cargo falls under load shall not be permitted to chafe on any...
Parker, Robert G.; Guo, Yi; Eritenel, Tugan; Ericson, Tristan M.
Vibration and noise caused by gear dynamics at the meshing teeth propagate through power transmission components to the surrounding environment. This study is devoted to developing computational tools to investigate the vibro-acoustic propagation of gear dynamics through a gearbox using different bearings. Detailed finite element/contact mechanics and boundary element models of the gear/bearing/housing system are established to compute the system vibration and noise propagation. Both vibration and acoustic models are validated by experiments including the vibration modal testing and sound field measurements. The effectiveness of each bearing type to disrupt vibration propagation is speed-dependent. Housing plays an important role in noise radiation .It, however, has limited effects on gear dynamics. Bearings are critical components in drivetrains. Accurate modeling of rolling element bearings is essential to assess vibration and noise of drivetrain systems. This study also seeks to fully describe the vibro-acoustic propagation of gear dynamics through a power-transmission system using rolling element and fluid film wave bearings. Fluid film wave bearings, which have higher damping than rolling element bearings, could offer an energy dissipation mechanism that reduces the gearbox noise. The effectiveness of each bearing type to disrupt vibration propagation in explored using multi-body computational models. These models include gears, shafts, rolling element and fluid film wave bearings, and the housing. Radiated noise is mapped from the gearbox surface to surrounding environment. The effectiveness of rolling element and fluid film wave bearings in breaking the vibro-acoustic propagation path from the gear to the housing is investigated.
Full Text Available The article portrays the results of experimental studies conducted in the field of static strength test of main landing gear of lightweight aircraft as well as in the area of establishing the pneumatic tyre characteristics of main landing gear. The studies were carried out in compliance with methodologies of performing studies for the purposes of solutions implemented in aviation structures. It was stated that static strength tests of landing gear should not be done with the use of shock absorbers, due to the fact that this element, distinguished by high viscoelastic properties, by being statically loaded, is subject to displacements that do not occur during normal operation of the aircraft. Excessive displacements of shock absorber result in the load distribution in other landing gear elements being incompatible with project assumptions, which in turn leads to this strength test being interrupted, bearing in mind significantly lower loads than anticipated. It was also concluded that in order to determine pneumatic tyre characteristics it is not necessary to carry out tests on the whole landing gear strut, because the results obtained in the compression test of the wheel itself with pneumatic tyre are identical as the results acquired during tests conducted in accordance with methodology. Test preparation process with the use of the wheel itself and its realization is less time-consuming, less expensive and does not entail the necessity to build complex test stands.
Benilha, S.; Belarifi, F.
The calculation of the gear teeth resistance, shows the using of a certain number of coefficients determined experimentally and which are accepted by the various international standards. However, this kind of calculation determines the gears by excess material and does not support the tribological parameters of operation. We propose in this work the support of these parameters, to determine the limit operation conditions of the spur gears, using the equivalent geometry. This is represented by two cylinders, which geometrically models of the contact between two teeth of a gear and whose lubrication is generally in mixed lubrication mode. The concept of Mc cool is used to determine the distribution of the load and the friction force, which are distributed in liquid (elastohydrodynamic) and solid domains and interact with each other. The phenomenon of interaction between the two domains is used, to predict the tribological limit conditions of operation. The proposed model is based on the resolution of elastohydrodynamic equations for the determination of load and friction as well as the deduction of mixed friction by tracing the Stribeck curve. This is calculated by the model of the decomposition of the patterns profile of rough surfaces in contacts. The results of non-dimensional calculations allow us to deduce the boundary conditions and can be adapted for any type of gear pair defined according to pre-established operating conditions.
Handschuh, Robert F.; Polly, Joseph; Morales, Wilfredo
An experimental program to determine the loss-of-lubrication (LOL) characteristics of spur gears in an aerospace simulation test facility has been completed. Tests were conducted using two different emergency lubricant types: (1) an oil mist system (two different misted lubricants) and (2) a grease injection system (two different grease types). Tests were conducted using a NASA Glenn test facility normally used for conducting contact fatigue. Tests were run at rotational speeds up to 10000 rpm using two different gear designs and two different gear materials. For the tests conducted using an air-oil misting system, a minimum lubricant injection rate was determined to permit the gear mesh to operate without failure for at least 1 hr. The tests allowed an elevated steady state temperature to be established. A basic 2-D heat transfer simulation has been developed to investigate temperatures of a simulated gear as a function of frictional behavior. The friction (heat generation source) between the meshing surfaces is related to the position in the meshing cycle, the load applied, and the amount of lubricant in the contact. Experimental conditions will be compared to those from the 2-D simulation.
Full Text Available In this study, an advanced method for the manufacture of spiral bevel and hypoid gears on CNC hypoid generators is proposed. The optmal head-cutter geometry and machine tool settings are determined to introduce the optimal tooth surface modifications into the teeth of spiral bevel and hypoid gears. The aim of these tooth surface modifications is to simultaneously reduce the tooth contact pressure and the transmission errors, to maximize the EHD load carrying capacity of the oil film, and to minimize power losses in the oil film. The proposed advanced method for the manufacture of spiral bevel and hypoid gears is based on machine tool setting variation on the cradle-type generator conducted by optimal polynomial functions and on the use of a CNC hypoid generator. An algorithm is developed for the execution of motions on the CNC hypoid generator using the optimal relations on the cradle-type machine. Effectiveness of the method was demonstrated by using spiral bevel and hypoid gear examples. Significant improvements in the operating characteristics of the gear pairs are achieved.
Byrne, G.D.; Hindmarsh, A.C.; Jackson, K.R.; Brown, H.G.
This is a sequel to the paper ''A comparison of two ODE codes: GEAR and EPISODE,'' and is concerned with the testing of two superficially similar ODE packages, GEAR and EPISODE. Fourteen basic test problems, some with several cases, are the basis for the testing. These problems represent several types--nonlinear systems with real and complex eigenvalues, linear systems with varied diagonal dominance, linear scalar problems, stiff and nonstiff problems, chemical kinetics with and without diurnal effect, and systems arising from the use of the numerical method of lines. Some problems are included in order to examine the options and error returns. The test results are presented in two forms: raw output and a comparative display of operation counts and of timings for the best method in the GEAR package and the best method in the EPISODE package. This approach allows a comparison of the consequences of the fixed-step interpolate strategy (GEAR) for changing step size against the truly variable step size strategy (EPISODE). It is concluded that EPISODE is generally faster than GEAR for problems involving wave fronts or transients on the interior of the interval of integration. For linear or simply decaying problems, these roles are usually reversed. 19 figures, 116 tables.
Abadjiev, Valentin; Kawasaki, Haruhisa
The computer design has improved forming different type software for scientific researches in the field of gearing theory as well as performing an adequate scientific support of the gear drives manufacture. Here are attached computer programs that are based on mathematical models as a result of scientific researches. The modern gear transmissions require the construction of new mathematical approaches to their geometric, technological and strength analysis. The process of optimization, synthesis and design is based on adequate iteration procedures to find out an optimal solution by varying definite parameters. The study is dedicated to accepted methodology in the creation of soft- ware for the synthesis of a class high reduction hyperboloid gears - Spiroid and Helicon ones (Spiroid and Helicon are trademarks registered by the Illinois Tool Works, Chicago, Ill). The developed basic computer products belong to software, based on original mathematical models. They are based on the two mathematical models for the synthesis: "upon a pitch contact point" and "upon a mesh region". Computer programs are worked out on the basis of the described mathematical models, and the relations between them are shown. The application of the shown approaches to the synthesis of commented gear drives is illustrated.
Interaction between individuals, whether it would be with colleagues, business partners or supervisors, is inevitable in every organisation. Collaborative work and aim for common goals encourages idea, experience and insight exchange. From time to time differences in opinions might arise, which result in value- related or intellectual clash, also known as a conflict. Therefore, it is paramount to know how to manage conflicts. In order to successfully overcome the conflicts, organisations shou...
Describes development of conflict-resolution framework to address committee conflict. Describes several conflict-resolution strategies. Matches appropriate strategies with different types of committee conflict. For example, compromise is listed at the appropriate strategy to resolve interpersonal conflict. (Contains 24 references.) (PKP)
Guan, Yuan H.; Shepard, W. Steve, Jr.; Lim, Teik C.; Li, Mingfeng
An internal active vibration control system is developed and verified experimentally to suppress gearbox housing vibrations due to gear transmission error excitation. The approach is based on an active shaft transverse vibration control concept. The system contains a piezoelectric stack actuator for applying control forces to the shaft via a rolling element bearing. A modified filtered-x LMS control algorithm with frequency estimation is developed to generate the appropriate control signals. The experimental results show 5-20 dB reduction in the housing vibration at the first two gear mesh harmonics over a wide gear rotation speed range. However, under certain narrow conditions, vibration amplifications at other locations are observed in the experiments, which might be attributed to the system un-modeled dynamics. In spite of this limitation, the approach developed is fairly promising. Studies are being performed to improve the overall performance of the prototype active control system.
Cooley, C. G.; Parker, R. G.; Vijayakar, S. M.
A finite element formulation for the dynamic response of gear pairs is proposed. Following an established approach in lumped parameter gear dynamic models, the static solution is used as the excitation in a frequency domain solution of the finite element vibration model. The nonlinear finite element/contact mechanics formulation provides accurate calculation of the static solution and average mesh stiffness that are used in the dynamic simulation. The frequency domain finite element calculation of dynamic response compares well with numerically integrated (time domain) finite element dynamic results and previously published experimental results. Simulation time with the proposed formulation is two orders of magnitude lower than numerically integrated dynamic results. This formulation admits system level dynamic gearbox response, which may include multiple gear meshes, flexible shafts, rolling element bearings, housing structures, and other deformable components.
Full Text Available The Samsung Gear 360 is a consumer grade spherical camera able to capture photos and videos. The aim of this work is to test the metric accuracy and the level of detail achievable with the Samsung Gear 360 coupled with digital modelling techniques based on photogrammetry/computer vision algorithms. Results demonstrate that the direct use of the projection generated inside the mobile phone or with Gear 360 Action Direction (the desktop software for post-processing have a relatively low metric accuracy. As results were in contrast with the accuracy achieved by using the original fisheye images (front and rear facing images in photogrammetric reconstructions, an alternative solution to generate the equirectangular projections was developed. A calibration aimed at understanding the intrinsic parameters of the two lenses camera, as well as their relative orientation, allowed one to generate new equirectangular projections from which a significant improvement of geometric accuracy has been achieved.
Full Text Available The article describes the concept of modular stand, where is possible to provide tests of gear pairs with fixed axes from mechanical automotive gearboxes, as well as tests of separate planetary sets from automatic gearboxes. Special attention in the article will be paid to the variant dedicated for testing of planetary gear sets. This variant is particularly interesting because: 1 it is rarely described in the literature, and 2 this topology allows big simplification with respect to testing of standard gearwheels. In the planetary closed-loop stand it is possible to directly link two identical planetary sets. Without any bracing flange or other connecting clutches, shafts or gear sets, just two planetary sets face-to-face will be assembled and connected to the electric motor.
Somprakit, Paisan; Huston, Ronald L.; Oswald, Fred B.
A new, innovative procedure called point load superposition for determining the contact stresses in mating gear teeth is presented. It is believed that this procedure will greatly extend both the range of applicability and the accuracy of gear contact stress analysis. Point load superposition is based upon fundamental solutions from the theory of elasticity. It is an iterative numerical procedure which has distinct advantages over the classical Hertz method, the finite element method, and over existing applications with the boundary element method. Specifically, friction and sliding effects, which are either excluded from or difficult to study with the classical methods, are routinely handled with the new procedure. Presented here are the basic theory and the algorithms. Several examples are given. Results are consistent with those of the classical theories. Applications to spur gears are discussed.
Somprakit, Paisan; Huston, Ronald L.; Oswald, Fred B.
A new, innovative procedure called point load superposition for determining the contact stresses in mating gear teeth. It is believed that this procedure will greatly extend both the range of applicability and the accuracy of gear contact stress analysis. Point load superposition is based upon fundamental solutions from the theory of elasticity. It is an iterative numerical procedure which has distinct advantages over the classical Hertz method, the finite element method, and over existing applications with the boundary element method. Specifically, friction and sliding effects, which are either excluded from or difficult to study with the classical methods, are routinely handled with the new procedure. Presented here are the basic theory and the algorithms. Several examples are given. Results are consistent with those of the classical theories. Applications to spur gears are discussed.
Lewy, Peter; Nielsen, J. Rasmus; Hovgård, Holger
Trawl surveys provide important information for evaluation of relative stock abundance fluctuations over time. Therefore, when survey gears or vessels are changed, it is important to compare the efficiency and selectivity of old and new gears and vessels. A method for estimation of conversion...... factors is developed based on a survey design where paired hauls are taken in the same trawl track line. The method explicitly accounts for changes in fish density caused by trawling disturbance. A generalized linear model for paired hauls catches is analytically derived and the gear conversion...... and disturbance parameters with their precision are obtained using standard software. Simulation studies carried out additionally showed that the estimated conversion factors were practically unbiased. Because of the independence of the spatial fish distribution, the new method is preferable to the traditional...
Full Text Available In this paper; a new method for gear pitting fault detection is presented. The presented method is developed based on a deep sparse autoencoder. The method integrates dictionary learning in sparse coding into a stacked autoencoder network. Sparse coding with dictionary learning is viewed as an adaptive feature extraction method for machinery fault diagnosis. An autoencoder is an unsupervised machine learning technique. A stacked autoencoder network with multiple hidden layers is considered to be a deep learning network. The presented method uses a stacked autoencoder network to perform the dictionary learning in sparse coding and extract features from raw vibration data automatically. These features are then used to perform gear pitting fault detection. The presented method is validated with vibration data collected from gear tests with pitting faults in a gearbox test rig and compared with an existing deep learning-based approach.
Ruhlin, C. L.; Doggett, R. V., Jr.; Gregory, R. A.
The paper describes an experimental and analytical study of the transonic flutter characteristics of an empennage flutter model having an all-movable horizontal tail with a geared elevator. Two configurations were flutter tested: one with a geared elevator and one with a locked elevator with the model cantilever-mounted on a sting in the wind tunnel. The geared-elevator configuration fluttered experimentally at about 20% higher dynamic pressures than the locked-elevator configuration. The experimental flutter boundary was nearly flat at transonic speeds for both configurations. It was found that an analysis which treated the elevator as a discrete surface predicted flutter dynamic pressure levels better than analyses which treated the stabilizer and elevator as a warped surface. Warped-surface methods, however, predicted more closely the experimental flutter frequencies and Mach number trends.
A series of night hauls were made both along a transect from the Danish coast to the Dogger Bank and at a fixed position in the southern North Sea. The aim was to evaluate the suitability of two midwater trawls (IKMT and MIK) for catching large herring larvae (20-40 mm), with special attention...... given to the influence of gear speed on catching effectiveness. An additional objective was to investigate larval distributional patterns of potential importance to sampling strategy. Gear speed had a pronounced influence on the efficiency of the IKMT. Catches per unit volume filtered decreased to one...... third when speed was increased by one knot. The efficiency of the MIK did not change in the speed range investigated, and this gear was in every case more efficient than the IKMT. Larvae were found to be patchily distributed at the scale of sampling, and the degree of patchiness did not increase when...
Xie, Liyang; Wu, Ningxiang; Qian, Wenxue
Time-dependent multi-configuration is a typical feature for mechanical systems such as gear trains and chain drives. As a series system, a gear train is distinct from a traditional series system, such as a chain, in load transmission path, system-component relationship, system functioning manner, as well as time-dependent system configuration. Firstly, the present paper defines time-domain series system to which the traditional series system reliability model is not adequate. Then, system specific reliability modeling technique is proposed for gear sets, including component (tooth) and subsystem (tooth-pair) load history description, material priori/posterior strength expression, time-dependent and system specific load-strength interference analysis, as well as statistically dependent failure events treatment. Consequently, several system reliability models are developed for gear sets with different tooth numbers in the scenario of tooth root material ultimate tensile strength failure. The application of the models is discussed in the last part, and the differences between the system specific reliability model and the traditional series system reliability model are illustrated by virtue of several numerical examples. - Highlights: • A new type of series system, i.e. time-domain multi-configuration series system is defined, that is of great significance to reliability modeling. • Multi-level statistical analysis based reliability modeling method is presented for gear transmission system. • Several system specific reliability models are established for gear set reliability estimation. • The differences between the traditional series system reliability model and the new model are illustrated.
Xue, Song; Howard, Ian
This paper aims to investigate the effectiveness of using the torsional vibration signal as a diagnostic tool for planetary gearbox faults detection. The traditional approach for condition monitoring of the planetary gear uses a stationary transducer mounted on the ring gear casing to measure all the vibration data when the planet gears pass by with the rotation of the carrier arm. However, the time variant vibration transfer paths between the stationary transducer and the rotating planet gear modulate the resultant vibration spectra and make it complex. Torsional vibration signals are theoretically free from this modulation effect and therefore, it is expected to be much easier and more effective to diagnose planetary gear faults using the fault diagnostic information extracted from the torsional vibration. In this paper, a 20 degree of freedom planetary gear lumped-parameter model was developed to obtain the gear dynamic response. In the model, the gear mesh stiffness variations are the main internal vibration generation mechanism and the finite element models were developed for calculation of the sun-planet and ring-planet gear mesh stiffnesses. Gear faults on different components were created in the finite element models to calculate the resultant gear mesh stiffnesses, which were incorporated into the planetary gear model later on to obtain the faulted vibration signal. Some advanced signal processing techniques were utilized to analyses the fault diagnostic results from the torsional vibration. It was found that the planetary gear torsional vibration not only successfully detected the gear fault, but also had the potential to indicate the location of the gear fault. As a result, the planetary gear torsional vibration can be considered an effective alternative approach for planetary gear condition monitoring.
Alla Yuryevna Borzova
Full Text Available The article considers features of Brazilian participation in peacekeeping missions under the auspices of the United Nations related to the commitment to preventive diplomacy in resolving the conflict, the combination of diplomacy and peace-building efforts and rehabilitation of the economies of countries-participants of the conflict. Brazil put forward the initiative “Supporters of mediation”, that adds the concept of the United Nations “Responsibility to Protect” (R2P with the concept “Responsibility while protecting” (RwhileP. Brazil advocates for human rights. It marked Brazil's position on the rejection of humanitarian intervention, since the use of force leads to increased violence and instability, which manifested itself in the situation in the Middle East, and mass migration. For the country is characterized the analysis of the sources of conflict, adherence to international law, and understanding of the relationship between security and sustainable development, which is reflected in Brazil's foreign policy strategy, national security strategy.
Suciu, F.; Dascalescu, A.; Ungureanu, M.
The asymmetric cylindrical gears, with involutes teeth profiles having different base circle diameters, are nonstandard gears, used with the aim to obtain better function parameters for the active profile. We will expect that the manufacturing of these gears became possible only after the design and realization of some specific tools. The paper present how the computer aided design and applications developed in MATLAB, for obtain the geometrical parameters, in the same time for calculation some functional parameters like stress and displacements, transmission error, efficiency of the gears and the 2D models, generated with AUTOLISP applications, are used for computer aided manufacturing of asymmetric gears with standard tools. So the specific tools considered one of the disadvantages of these gears are not necessary and implicitly the expected supplementary costs are reduced. The calculus algorithm established for the asymmetric gear design application use the „direct design“ of the spur gears. This method offers the possibility of determining first the parameters of the gears, followed by the determination of the asymmetric gear rack’s parameters, based on those of the gears. Using original design method and computer applications have been determined the geometrical parameters, the 2D and 3D models of the asymmetric gears and on the base of these models have been manufacturing on CNC machine tool asymmetric gears.
A. M. Dankov
Full Text Available The known attempts to create a continuously-adjustable gear train with solid gears have led to development of some so-called adaptive gears. The most structurally simple version of continuously- adjustable gear train is a two-wheel planetary gear. It is an obvious fact that an active regulation of gear ratio for the gear should be based on the presence of con- trolled elements (parameters and a mechanism for their control. In respect of the mentioned gear one of the controlled elements that is a compound central toothed gear has such controlled parameter as a nominal pitch diameter. In this case it can rotate or remain motionless. Other controlled element which is a planetary carrier has its own radius as a controlled parameter and makes a rotary motion with a great speed of a leading element. The purpose of the control mechanism is to ensure radial displacement of central toothed gear and planet gear sectors in the working gear. The paper describes the mechanism modifications and considers two variants for transfer of control action from its source to an object to be controlled. The transfer is ensured by mechanical gears (two variants and hydraulics.
Bae, M. H.; Bae, T. Y.; Kim, D. J.
The power train of mixer gearbox for concrete mixer truck includes differential planetary gears to get large reduction ratio for operating mixer a drum and simple structure. The planetary gears are very important part of a mixer gearbox where strength problems namely gear bending stress, gear compressive stress and scoring failure are the main concern. In the present study, calculating specifications of the differential planetary gears and analyzing the gear bending and compressive stresses as well as scoring factor of the differential planetary gears gearbox for an optimal design of the mixer gearbox in respect to cost and reliability are investigated. The analyses of actual gear bending and compressive stresses of the differential planetary gears using Lewes & Hertz equation and verifications of the calculated specifications of the differential planetary gears evaluate the results with the data of allowable bending and compressive stress from the Stress-No. of cycles curves of gears. In addition, we also analyze actual gear scoring factor as well as evaluate the possibility of scoring failure of the differential planetary gear.
Ohio Commission on Dispute Resolution and Conflict Management, Columbus.
Noting that the conflicts arising daily for young children provide an opportunity for adults to model and teach skills for handling conflict peacefully, this guide provides tips for preventing unnecessary conflict, offers "first aid" for conflict moments, and provides resources for addressing common situations that can cause conflict.…
Most analyses of conflict assume that conflicting groups act in a unitary fashion. This assumption is often violated: to reduce their risk of replacement, group leaders prevent both group members and soldiers from acting collectively, making it difficult for leaders to make credible commitments to them. Lifting the assumption that groups are unitary shifts the analysis of a wide range of c...
The results also show that the management strategies mostly adopted in conflict resolution within the study area is “Negotiation and Re-negotiation” which is rated highest with 53%. Furthermore, the most important technique employed in conflict prevention is “Definition of roles and responsibilities” with percentage rating of ...
Frandsen, Tommy; Mathe, Laszlo; Berg, Nick Ilsø
This paper presents the physical construction and test results of two new demonstrators of a Motor Integrated Permanent Magnet Gear (MIPMG), which is a second version of an already tested demonstrator. The demonstrators will be used as traction units for a Battery Electrical Vehicle (BEV) and the......This paper presents the physical construction and test results of two new demonstrators of a Motor Integrated Permanent Magnet Gear (MIPMG), which is a second version of an already tested demonstrator. The demonstrators will be used as traction units for a Battery Electrical Vehicle (BEV...
Frandsen, Tommy; Mathe, Laszlo; Berg, Nick Ilsø
This paper presents the physical construction and test results of two new demonstrators of a Motor Integrated Permanent Magnet Gear (MIPMG), which is a second version of an already tested demonstrator. The demonstrators will be used as traction units for a Battery Electrical Vehicle (BEV) and the......This paper presents the physical construction and test results of two new demonstrators of a Motor Integrated Permanent Magnet Gear (MIPMG), which is a second version of an already tested demonstrator. The demonstrators will be used as traction units for a Battery Electrical Vehicle (BEV...
Radicella Andrea Chiaramonte
Full Text Available After having described gear wheels with teeth having the two sides constituted by different involutes and their importance in engineering applications, we stress the need for an efficient procedure for the automatic mesh generation of innovative gear teeth. First, we describe the procedure for the subdivision of the tooth profile in the various possible cases, then we show the method for creating the subdivision mesh, defined by two series of curves called meridians and parallels. Finally, we describe how the above procedure for automatic mesh generation is able to solve specific cases that may arise when dealing with teeth having the two sides constituted by different involutes.
Full Text Available The paper concerns analysis of gears hardening process. In order to obtain required temperature distribution several variations of single and combined frequencies for selected gear-wheel configurations were considered. The paper includes the calculation models and analysis of geometry and current intensity as well frequency influence on temperature distribution of the tooth surface. All calculations have been carried out by means of the use of Flux3D simulation program, which enables to provide, coupled electromagnetic and temperature fields analysis.
Full Text Available This contribution deals with the issue of electron beam welding of high-accurate gear wheels composed of a spur gearing and fluted shaft joined with a face weld for automotive industry. Both parts made of the high-strength low-alloy steel are welded in the condition after final machining and heat treatment, performed by case hardening, whereas it is required that the run-out in the critical point of weldment after welding, i. e. after the final operation, would be 0.04 mm max..
The article presents the potential problems related to conflict resolution while cooperating in multicultural teams. Special attention is paid to specific character of such teams as well as to the concept of productive conflict and the ways of resolving it. The experiences gained in the Erasmus Intenstive Programme - Effective Working in Multicultural Teams were used.
Full Text Available The article presents the potential problems related to conflict resolution while cooperating in multicultural teams. Special attention is paid to specific character of such teams as well as to the concept of productive conflict and the ways of resolving it. The experiences gained in the Erasmus Intenstive Programme - Effective Working in Multicultural Teams were used.
Papaioannou, Kostadis J.
This paper offers a historical micro-level analysis of the impact of climate shocks on the incidence of civil conflict in colonial Nigeria (1912-1945). Primary historical sources on court cases, prisoners and homicides are used to capture conflict. To measure climate shocks we use the deviation
Friis, Karsten; Ringsmose, Jens
Over the past two decades, a new man-made domain of conflict has materialized. Alongside armed conflict in the domains of land, sea, air, and space, hostilities between different types of political actors are now taking place in cyberspace. This volume addresses the challenges posed by cyberspace...
Albertini, G.; Fiori, F.; Girardin, E.; Giuliani, A.; Pyzalla, A.; Quadrini, E.
Complete text of publication follows. Thermal austenitizing and tempering treatments are being developed in automotive industry to prevent crack initiation and avoid crack propagation, especially in components where stress intensity factors influence the stress field and then the fatigue life of the component itself. This is the case of crown gears, where the teeth root undergoes frequently to cracking when tensile residual stresses are present at the surface, as typical loads are impulsive and very high. The sign reversal of these stresses is the aim of austenitizing and tempering treatments. In this work residual stress measurements carried out at HMI-BENSC are presented, in a UNI55Cr3 steel crown gear submitted to such kind of treatments, performed with a new multi-frequency induction technique whose effectiveness is checked. (author)
According to the participants, the indigenous institutions can play a major role in preventing and resolving intra-ethnic conflicts. * Zigale Tamir Tenaw is assistant professor in the Department of Gender and Development. Studies, College of Social Sciences and Humanities, Haramaya University, Dire. Dawa, Ethiopia.
The essence, fulcrum or goal of International Humanitarian Law is to limit, for humanitarian reasons, the effect of armed conflict. It seeks to do so by means of rules that protect persons who do not or are no longer participating in the hostilities, that restrict the means and methods of conducting hostilities and that prevent the ...
Wagoner, Brady; Brescó, Ignacio
This introduction to the special issue on conflict and memory aims to underscore the importance of memory (whether individual and collective) in relation to intergroup conflicts. We argue that the way in which societies reconstruct and bring the past into the present—especially, the historical past......—is crucial when it comes to the study of intergroup conflict dynamics. In this regard, we also highlight the growing importance of memory studies within the area of social sciences as well as the multiple ways of approaching memory. Drawing from this wide theoretical framework, we introduce the articles...... of this issue, eight articles that tackle the role of memory in different conflicts, whether currently under way, in progress of being resolved, in postwar settings, or in contexts conflicts expected to happen do not arise....
Højholt, Charlotte; Kousholt, Dorte
to turn into conflicts and the conflicts have personal and existential meanings to the participant in social practice (related to their possibilities for conducting everyday life) and they are historical and political (related to societal questions about education). We draw on conceptualizations of social......In this paper, we aim to develop a dialectical approach to analyzing social conflicts concerning children’s school life. Public education can be seen as a common cause different parties at the same time are engaged in and conflicting about. We want to discuss this unity between the distribution...... practice as contradictory and developed through its contradictions (Lave, Dreier, Axel). The theoretical discussion will be illustrated through examples from conflicts between children and between parents - in relation to dealing with focus on the tasks of the school as well as flexibility in relation...
Kevane, Michael; Gray, Leslie
Data on rainfall patterns only weakly corroborate the claim that climate change explains the Darfur conflict that began in 2003 and has claimed more than 200 000 lives and displaced more than two million persons. Rainfall in Darfur did not decline significantly in the years prior to the eruption of major conflict in 2003; rainfall exhibited a flat trend in the thirty years preceding the conflict (1972-2002). The rainfall evidence suggests instead a break around 1971. Rainfall is basically stationary over the pre- and post-1971 sub-periods. The break is larger for the more northerly rainfall stations, and is less noticeable for En Nahud. Rainfall in Darfur did indeed decline, but the decline happened over 30 years before the conflict erupted. Preliminary analysis suggests little merit to the proposition that a structural break several decades earlier is a reasonable predictor of the outbreak of large-scale civil conflict in Africa
Simmonds, Joshua; Constantinides, Prometheas; Perry, J Christopher; Drapeau, Martin; Sheptycki, Amanda R
Psychodynamic psychotherapies suggest that symptomatic relief is provided, in part, with the resolution of psychic conflicts. Clinical researchers have used innovative methods to investigate such phenomenon. This article aims to review the literature on quantitative psychodynamic conflict rating scales. An electronic search of the literature was conducted to retrieve quantitative observer-rated scales used to assess conflict noting each measure's theoretical model, information source, and training and clinical experience required. Scales were also examined for levels of reliability and validity. Five quantitative observer-rated conflict scales were identified. Reliability varied from poor to excellent with each measure demonstrating good validity. However a small number of studies and limited links to current conflict theory suggest further clinical research is needed.
of crop farmers and nomads respectively had less than 20 years of farming experience Also the results showed that problems encountered by the crop farmers were crop destruction (22.89 %) and sexual harassment (20.65 %) while cattle theft (69.57 %) and language barrier (30.43 %) were those of the nomads. Conflicts ...
African Journal on Conflict Resolution ... The United Nations Organisation (UN) is best endowed to conduct preventive diplomacy (PD) by preventing disputes and conflicts arising from interstate and ... The UN has the means to prevent such conflicts and disputes from emerging and escalating into armed confrontation.
Danjoux Meth, Nathalie; Lawless, Bernard; Hawryluck, Laura
The purpose of this study is to understand conflicts in the ICU setting as experienced by clinicians and administrators and explore methods currently used to resolve such conflicts when there may be discordance between clinicians and families, caregivers or administration. Qualitative case study methodology using semi-structured interviews was used. The sample included community and academic health science centres in 16 hospitals from across the province of Ontario, Canada. A total of 42 participants including hospital administrators and ICU clinicians were interviewed. Participants were sampled purposively to ensure representation. The most common source of conflict in the ICU is a result of disagreement about the goals of treatment. Such conflicts arise between the ICU and referring teams (inter-team), among members of the ICU team (intra-team), and between the ICU team and patients' family/substitute decision-maker (SDM). Inter- and intra-team conflicts often contribute to conflicts between the ICU team and families. Various themes were identified as contributing factors that may influence conflict resolution practices as well as the various consequences and challenges of conflict situations. Limitations of current conflict resolution policies were revealed as well as suggested strategies to improve practice. There is considerable variability in dealing with conflicts in the ICU. Greater attention is needed at a systems level to support a culture aimed at prevention and resolution of conflicts to avoid increased sources of anxiety, stress and burnout.
An integrated tooth contact analysis (TCA) computer program for the simulation of meshing and contact of gear drives that calculates transmission errors and shift of hearing contact for misaligned gear drives has been developed...
Townsend, Dennis P.; Patel, P. R.
Spur gear surface endurance tests were conducted to investigate CBN ground AISI 9310 spur gears for use in aircraft applications, to determine their endurance characteristics and to compare the results with the endurance of standard vitreous ground AISI 9310 spur gears. Tests were conducted with VIM-VAR AISI 9310 carburized and hardened gears that were finish ground with either CBN or vitreous grinding methods. Test conditions were an inlet oil temeprature of 320 K (116 F), an outlet oil temperature of 350 K (170 F), a maximum Hertz stress of 1.71 GPa (248 ksi), and a speed of 10,000 rpm. The CBN ground gears exhibited a surface fatigue life that was slightly better than the vitreous ground gears. The subsurface residual stress of the CBN ground gears was approximately the same as that for the standard vitreous ground gears for the CBN grinding method used.
Full Text Available A spiral bevel gear system supported on thrust bearings considering the coupled bending-torsional nonlinear vibration is proposed and an eight degrees of freedom (8DOF lumped parameter dynamic model of the spiral bevel gear system combined with time-varying stiffness, static transmission error, gear backlash, and bearing clearances is investigated. The spiral bevel gear system is analyzed with the equations of motion and the dynamic response is solved using the Runge-Kutta method. The effects of mesh frequency, mesh damping coefficient, load coefficient, and gear backlash are revealed, which describe the true mesh characteristics of the spiral bevel gear system. The bifurcation characteristics as jump discontinuities, periodic windows, and chaos are obtained by studying time histories, phase plane portraits, Poincaré maps, Fourier spectra, and global bifurcation diagrams of the gear system. The results presented in this study provide some useful information for engineers in designing and controlling such gear systems.
Ch. I. Zhdanovich; N. V. Kalinin
A methodology has been developed for selection of gear number and transmission gear ratios in mechanical part of a wheel-type tractor with electro-mechanical transmission containing a propulsion asynchronous electric motor with variablefrequency control. The paper proposes to determine a transmission gear ratio on the basis of the following: provision of wheel torque dependence on tractor speed which is the best one for a traction process and during transfer from one gear to the other; provis...
...— (1) 300% and not more than 375% of the rated full-load current of one steering-gear motor for a direct-current motor; or (2) 175% and not more than 200% of the locked-rotor current of one steering-gear... steering-gear motor, nor a motor for a steering-gear control system, may be protected by an overload...
Blagojević Ivan A.; Vorotović Goran S.; Stamenković Dragan D.; Petrović Nebojša B.; Rakićević Branislav B.
The manner of gear shifting is one of the main factors affecting the fuel efficiency of motor vehicles. Potential savings resulted from optimized gear shifting led to introduction of gear shift indicators in passenger vehicles as an obligation from year 2012. The effects of gear shift indicators usage are still not studied enough. That was the motive for the authors to conduct the experiments to justify their usage, both from the economic and ecological standpoint. The presented results come ...
Raines, Susan S
"Raines masterfully blends the latest empirical research on workplace conflict with practical knowledge, skills, and tools to effectively manage and prevent a wide range of conflict episodes. This is a highly applicable 'top shelf book' that will assist anyone from the aspiring manager to top level management and leadership in the public, private, and nonprofit sectors. It will also be a fast favorite of professors, trainers, and students of business and conflict management."- Brian Polkinghorn, Distinguished Professor, Center for Conflict Resolution, Salisbury University. "With her broad dis
Rasmussen, Peter Omand; Frandsen, Tommy; Jensen, Kasper Køtter
This paper presents test results of a new motor integrated permanent magnet gear and clarifies a path for future optimizations. The prototype, which fabrication also is described, is initially targeting electrical traction for vehicles. Basic measured parameters in form of back-emf, stall torque...
Frandsen, Tommy; Rasmussen, Peter Omand
This paper presents an investigation of the eddycurrent losses caused by 3D effects in a Motor Integrated Permanent Magnet Gear (MIPMG). Two prototypes of a MIPMG have been designed and build to be used as traction units for an electric vehicle. The measured efficiency of the MIPMG is superior...
In this study, we used multivariate and ecological approaches to evaluate gear competition and interactions between artisanal and aquarium fishers using a case study of the Shimoni area, southcoast of Kenya. Aquarium fisher catches were monitored from September 2010 to March 2013; while artisanal fisher catches were ...
Full Text Available The severity of gear noise response depends on the sensitivity of geared rotor system dynamics to the transmission error. As gearbox design trending towards lighter weight and lower noise, the influence of housing compliance on system dynamic characteristics cannot be ignored. In this study, a gear-shaft-bearing-housing coupled impedance model is proposed to account for the effect of housing compliance on the vibration of geared transmission system. This proposed dynamic model offers convenient modeling, efficient computing, and ability to combine computed parameters with experimental ones. The numerical simulations on system dynamic characteristics are performed for both a rigid housing configuration and a flexible one. Natural frequencies, dynamic mesh forces, and dynamic bearing reaction loads are computed, and the housing compliance contribution on system dynamic characteristics is analyzed. Results show that increasing housing compliance will decrease the system natural frequencies and will affect the dynamic bearing reaction loads significantly but have very little influence on the dynamic mesh force. Also, the analysis shows that bearing stiffness has significant influence on the degree of housing contribution on system dynamic characteristics.
Půst, Ladislav; Pešek, Luděk; Radolfová, Alena
Roč. 821, č. 2016 (2016), s. 284-281 ISSN 1660-9336 R&D Projects: GA TA ČR TA04011656 Institutional support: RVO:61388998 Keywords : lanetary gearings set * vibrations * rig wheel excitation * driving aggregate Subject RIV: BI - Acoustics
Table 1 while Table 2 shows the result of the commonest crafts observed during the period of study. Table 1: FISHING GEARS OBSERVED DURING THE STUDY PERIOD. ENGLISH NAME. LOCAL NAMES. Jukun. Hausa. Tiv. Scoop net. Aga. Homa. Kpe u kase. Doubled chamber cane trap Xjini. Ndurutu. Ikya. Woven trap.
There are many methods available for developing profiles of gear and spline teeth. Most of the techniques are inaccurate because they use only an approximation of the involute curve profile. The parametric method developed in this paper provides accurate involute curve creation using formulas and exact geometric ...
Abstract. There are many methods available for developing profiles of gear and spline teeth. Most of the techniques are inaccurate because they use only an approximation of the involute curve profile. The parametric method developed in this paper provides accurate involute curve creation using formulas and exact ...
A. I. Safonov
Full Text Available The paper analyzes factors that determine dynamic loads of mechanical transmission of trolleybus traction driving gear. The paper proposes a methodology for determination of calculative moments of loading transmission elements. Results of the research are analyzed and recommendations on dynamic reduction of trolleybus transmission are given in the paper.
V. P. Morozov
Full Text Available The principle of "early matching" aircraft aerohydrodynamic layouts with air cushion landing gear is suggested. Application of this principle is considered as an example of adaptation to the ball screw base circuit of light transport aircraft. The principle, other than weight, aerodynamic, technological and operational requirements includes additional project activities related to the installation of ball screws.
...) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Gear and Equipment for Rigging and Materials... the hook or the load. (j) Loads (tools, equipment or other materials) shall not be swung or suspended... hatch through which materials or equipment are being raised, lowered, moved, or otherwise shifted...
... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Fixed gear fishery-prohibitions. 660.212 Section 660.212 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES West Coast...
... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Fixed gear sablefish fishery management. 660.372 Section 660.372 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES...
... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Fixed gear fishery-definitions. 660.211 Section 660.211 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES West Coast...
... supply such ratings, the employer shall use the tables for wire rope and wire rope slings found in..., as indicated in table 4B of appendix II to this part, is reached at any point of a link. (iv) Chain..., loose gear such as slings, chains, bridles, blocks and hooks shall be so placed as to avoid damage to...
van Soest, A.J.
A simple model of the bicycle drive system with a non-circular front chain ring is proposed and an algorithm is devised for calculation of the corresponding Gear Ratio As a Function Of Crank Angle (GRAFOCA). It is shown that the true effective radius of the chain ring is always the perpendicular
An experimental data set is used to compare the diagnostic capability of the fast Fourier transform power spectrum to the wavelet envelope power spectrum as respectively computed using Laplace and Morlet wavelet functions. The gear testing apparatus was used for experimental studies to obtain the vibration signal from ...
(8.8%) and Bagrus spp. (2.6%). Catches by 'atidza' and basket traps were predominantly Tilapias and Chrysichthys spp., respectively, while that by gillnets and net traps were more heterogeneous. The highest catch of 20 t during the period was made by basket traps, while that from the other gears ranged from 0.33 to 6 t ...
Iba, Daisuke; Rodriguez Lopez, Ricardo; Kamimoto, Takahiro; Nakamura, Morimasa; Miura, Nanako; Iizuka, Takashi; Masuda, Arata; Moriwaki, Ichiro; Sone, Akira
The long-term objective of our research is to develop sensor systems for detection of gear failure signs. As a very first step, this paper proposes a new method to create sensors directly printed on gears by a printer and conductive ink, and shows the printing system configuration and the procedure of sensor development. The developing printer system is a laser sintering system consisting of a laser and CNC machinery. The laser is able to synthesize micro conductive patterns, and introduced to the CNC machinery as a tool. In order to synthesize sensors on gears, we first design the micro-circuit pattern on a gear through the use of 3D-CAD, and create a program (G-code) for the CNC machinery by CAM. This paper shows initial experiments with the laser sintering process in order to obtain the optimal parameters for the laser setting. This new method proposed here may provide a new manufacturing process for mechanical parts, which have an additional functionality to detect failure, and possible improvements include creating more economical and sustainable systems.
Full Text Available In order to reduce wind energy costs, prognostics and health management (PHM of wind turbine is needed to ensure the reliability and availability of wind turbines. A gearbox is an important component of a wind turbine. Therefore, developing effective gearbox fault detection tools is important to the PHM of wind turbine. In this paper, a new acoustic emission (AE sensor based gear fault detection approach is presented. This approach combines a heterodyne based frequency reduction technique with time synchronous average (TSA and spectrum kurtosis (SK to process AE sensor signals and extract features as condition indictors for gear fault detection. Heterodyne technique commonly used in communication is first employed to preprocess the AE signals before sampling. By heterodyning, the AE signal frequency is down shifted from several hundred kHz to below 50 kHz. This reduced AE signal sampling rate is comparable to that of vibration signals. The presented approach is validated using seeded gear tooth crack fault tests on a notational split torque gearbox. The approach presented in this paper is physics based and the validation results have showed that it could effectively detect the gear faults.
Yuan, Jing; He, Zhengjia; Zi, Yanyang
Fault symptoms of running gearboxes must be detected as early as possible to avoid serious accidents. Diverse advanced methods are developed for this challenging task. However, for multiwavelet transforms, the fixed basis functions independent of the input dynamic response signals will possibly reduce the accuracy of fault diagnosis. Meanwhile, for multiwavelet denoising technique, the universal threshold denoising tends to overkill important but weak features in gear fault diagnosis. To overcome the shortcoming, a novel method incorporating customized (i.e., signal-based) multiwavelet lifting schemes with sliding window denoising is proposed in this paper. On the basis of Hermite spline interpolation, various vector prediction and update operators with the desirable properties of biorthogonality, symmetry, short support and vanishing moments are constructed. The customized lifting-based multiwavelets for feature matching are chosen by the minimum entropy principle. Due to the periodic characteristics of gearbox vibration signals, sliding window denoising favorable to retain valuable information as much as possible is employed to extract and identify the fault features in gearbox signals. The proposed method is applied to simulation experiments, gear fault diagnosis and normal gear detection to testify the efficiency and reliability. The results show that the method involving the selection of appropriate basis functions and the proper feature extraction technique could act as an effective and promising tool for gear fault detection.
... starting must have a built-in start-in-gear protection device. (2) Outboard motors designed for remote... this motor must comply with USCG requirements for start-in-gear protection in 33 CFR Part 183, Subpart... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Start-in-gear protection required...
... 34 Education 3 2010-07-01 2010-07-01 false What priorities may the Secretary establish for a GEAR... FOR UNDERGRADUATE PROGRAMS (GEAR UP) § 694.15 What priorities may the Secretary establish for a GEAR... Community designated by the U.S. Department of Housing and Urban Development or the U.S. Department of...
... 46 Shipping 7 2010-10-01 2010-10-01 false Steering gear, controls, and communication system tests... gear, controls, and communication system tests. The master of a vessel shall have examined and tested the steering gear, signaling whistle, propulsion controls, and communication systems of the vessel...
... 46 Shipping 4 2010-10-01 2010-10-01 false Steering gear, whistle, and means of communication. 131... examine and test the steering gear, the whistle, and the means of communication between the pilothouse and... VESSELS OPERATIONS Tests, Drills, and Inspections § 131.505 Steering gear, whistle, and means of...
... COMMERCIAL FISHING INDUSTRY VESSELS Stability § 28.545 Intact stability when using lifting gear. (a) Each vessel which lifts a weight over the side, or that uses fishing gear that can impose an overturning...=displacement of the vessel with the lifted weight or the force on the fishing gear included, in long tons...
... 46 Shipping 7 2010-10-01 2010-10-01 false Weight handling gear manufactured prior to March 1, 1968. 189.35-90 Section 189.35-90 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... gear manufactured prior to March 1, 1968. (a) Weight handling gear manufactured prior to March 1, 1968...
M. N. Pischov
Full Text Available The paper dwells upon the necessity to increase the operating life of the toothed gearing of skidder transmission by means of strengthening by complex borating. The methodology of comparative testing of tooth gear as well as the stand construction are described. The causes of destruction of tooth gear surface strengthened by different methods have been determined.
Goldstein, Yariv; Dolkart, Oleg; Kaufman, Ehud; Amar, Eyal; Sharfman, Zachary T; Rath, Ehud; Mozes, Gavriel; Maman, Eran
The popularity of bicycle riding for recreation, exercise and transportation has grown enormously in recent years, which has led to an increased incidence of bicycle-related injuries. While these injuries involve mainly the musculoskeletal system, data on shoulder-specific injuries incurred while bike riding are lacking. Classifying these shoulder injuries may provide insight and assistance in the creation and implementation of effective protective gear and measures. To investigate the types and mechanisms of shoulder injuries among cyclists. This study retrospectively examined all cyclists who incurred shoulder injuries while riding and were admitted to the emergency department and shoulder clinic between January 2008 and November 2013. The study included 157 subjects with various bicycle-related shoulder injuries treated with either conservative or surgical measures. Eighty-four percent of injuries were caused by a direct blow to the shoulder, 7% by falling on an outstretched hand, 6% were traction injuries, and 3% were due to hyperabduction. Nine different clinical types of injury were observed; the most common injuries were clavicle fractures (32%), followed by acromioclavicular joint dislocations (22%), rotator cuff tears (22%), and humeral fractures (8%). Fifty-one percent of subjects were managed with conservative care and the remaining patients required surgical interventions. Shoulder injuries incurred while riding a bicycle span the entire spectrum of shoulder injuries and often result in debilitating conditions. Although the use of helmets is increasing, there is currently no effective protective gear or measures to prevent riders from suffering shoulder injuries.
Full Text Available There is a tendency of similar idea that caught the conflict prevention and management efforts nowadays to the articles of the Charter of Medina which was religious-based and containing the theory of civil society. It I mostly on the handling of conflict which tends to take preventive measures and to stop the conflict directly, as well as making a comprehensive synergistic effort to mange conflict. Conflict prevention is a core component of a comprehensive Conflict Management Program. This paper explores the conflict that occurred in Ponianak between a group of people from ethnic Dayak and members of an Islamic organization in 2012 which includes an important lesson for the people of West Kalimantan, both for the government and the community elements especially in dealing with a dispute between different groups of people. An integrative prevention has been proven to be able to answer the question of handling a conflict that has a potential to escalate into a full-scale riot. This work concludes that an integrative conflict handling model may become a viable alternative model to be adopted by the community of West Kalimantan in particular and other societies in general. A synergic integrative conflict handling model that reflects local wisdom of the people of Pontianak is expected to inspire real peace for various communities with a multicultural background. Key words: multicultural, religious-based conflict, ethnicity, religion
O'Neill, F. G.; Summerbell, K.; Ivanović, A.
The contact demersal towed fishing gears make with the seabed can lead to penetration of the substrate, lateral displacement of the sediment and a pressure field transmitted through the sediment. It will also contribute to the overall drag of the fishing gear. Consequently, there can be environmental effects such as habitat alteration and benthic mortality, and impacts to the fuel efficiency of the fishing operation which will affect emissions of nitrogen oxides, sulphur oxides and greenhouse gases such as CO2. Here we present the results of experimental trials that measure the contact drag of a range of elements that represent some of the components of towed demersal gears that are in contact with the seabed. We show that the contact drag of the gear components depends on their weight, geometry, the type of sediment on which they are towed and whether they are rolling or not. As expected, the contact drag of each gear component increases as its weight increases and the drag of fixed elements is greater than that of the rolling ones. The dependence on aspect ratio is more complex and the drag (per unit area) of narrow cylinders is less than that of wider ones when they roll on the finer sediment or are fixed (not permitted to roll) on the coarser sediment. When they roll on the coarse sediment there is no dependence on aspect ratio. Our results also suggest that fixed components may penetrate the seabed to a lesser depth when they are towed at higher speeds but when they roll there is no such relationship.
sacrifices that she has made all these years. I would like to thank my parents and my little sister (Fikret, Nermin, and Nurgul) for their continuing...enthusiastic political speeches. It needs to go trough stages: infancy, adolescence , and adulthood.11 Thus, in Chapter IV, I discuss the value of...imminent conflict. In Sri Lanka, the Liberation Tigers of Tamil Elam—one of the most violent movements in the world, which seeks a Tamil state in northern
Nielsen, Jannie Jessen; Sørensen, John Dalsgaard
of the damage, and can be used for Bayesian updating of a damage model used for risk-based decision making. For this decision problem, the risk of failure should be compared to the cost of preventive maintenance. The hypothesis that the maximum pitch motor torque is an indicator of the damage size is supported...... by results from a measurement campaign where measurements are available both before and after maintenance was performed. The loads dramatically decreased after the maintenance. However, after a few more months of measurements, and by including data from the SCADA system, it became obvious that seasonal...
Full Text Available Couple relations are characterized as relations of an intimate nature dominated by constant interaction or strong interdependence and mutual influence of intense feelings between spouses. In marriages where there is conflict, there are typical examples of interaction, which result in high proportion of negative communicative acts that affect the quality of marital relationships such as: loss of confidence, the emergence of frustration, feelings of anxiety, discomfort, leading to escalation of marital conflicts. Communication as a variable has a large impact on the resolution of marital conflicts. The obtained results of our research indicate that the choice of different strategies of behavior in conflict situations among our respondents primarily depend on: the degree of persistence in the pursuit of its own interests and level of cooperation in addressing the interests of others.
Blunk, Elizabeth M.; Russell, Elizabeth Morgan; Armga, Carol J.
The purpose of this qualitative study was to explore early childhood teachers' interventions during peer conflict. Fifteen ethnically diverse teachers in central Texas were asked to reflect on videotaped peer conflict situations. Using thematic analysis, five strategy themes were identified: prevent aggression, consider timing, stop conflict,…
Ashby, Nicole; Neilsen-Hewett, Cathrine
The importance of conflict and its resolution for children's short- and long-term adjustment has been well established within the research literature. Conflict and conflict resolution differs according to a number of constructs, including age, gender and relationship status. The purpose of this study was to explore conflict origins, resolution…
Powers, Richard B.; Kirkpatrick, Kat
Playing With Conflict is a weekend course for graduate students in Portland State University's Conflict Resolution program and undergraduates in all majors. Students participate in simulations, games, and experiential exercises to learn and practice conflict resolution skills. Graduate students create a guided role-play of a conflict. In addition…
Brack, Greg; Lassiter, Pamela S.; Hill, Michele B.; Moore, Sarah A.
Counselors often engage in conflict mediation in professional practice. A model for understanding the complex and subtle nature of conflict resolution is presented. The ecosystemic complexity theory of conflict is offered to assist practitioners in navigating the fog of conflict. Theoretical assumptions are discussed with implications for clinical…
This article tries to show the impacts of conflict on women, the role of women in conflict and indigenous conflict resolution, and the participation of women in social institutions and ceremonies among the Issa and Gurgura clans of the Somali ethnic group. It explores the system of conflict resolution in these clans, and ...
Muzaffer Ercan Yılmaz
This study provides an analytical discussion for the issue of religious fundamentalism and itsrelevance to conflict, in its broader sense. It is stressed that religious fundamentalism manifests itself in twoways: nonviolent intolerance and violent intolerance. The sources of both types of intolerance and theirconnection to conflict are addressed and discussed in detail. Further research is also suggested on conditionsconnecting religion to nonviolent intolerance so as to cope with the problem...
Full Text Available Footprint 19 focuses on the more recent roles of architecture in the contemporary spaces of conflict. Departing from a spatial understanding of geopolitical, climatological and economical conflicts, the various contributions highlight the large scale and phenomenal transitions in the physical world and in society by extrapolating, through examples, the abundance of relations that can be traced between conflict, territory and architecture. Conflict areas often prove to be fertile grounds for innovation and for the emergence of new spatial forms. The issue reports on the state of perpetual global unrest in architecture through a series of articles and case studies that highlight the consequences of conflicts in the places and spaces that we inhabit. In the introduction, these are discussed as an interlinked global reality rather than as isolated incidents. In doing so, the contemporary spaces of conflict are positioned in the context of emerging global trends, conditions, and discourses in the attempt to address their indicative symptoms while reflecting on their underlying causes.
Kumar, Pawan; Aggarwal, M. L.
Spin hardening inductors are typically used for fine-sized teeth gear geometry. With the proper selection of several design parameters, only the gear teeth can be case surface hardened without affecting the other surface of gear. Preheating may be done to reach an adapted high austenitizing temperature in the root circle to avoid overheating of the tooth tip during final heating. The effect of preheating of gear on control of compressive residual stresses and case hardening has been experimentally discussed in this paper. Present work is about analysing single frequency mode, preheat hardening treatment and compressive residual stresses field for hardening process of spur gear using spin hardening inductors.
Litvin, F. L.; Chen, N. X.; Hsiao, C. L.; Handschuh, Robert F.
Analysis of helical involute gears by tooth contact analysis shows that such gears are very sensitive to angular misalignment that leads to edge contact and the potential for high vibration. A new topology of tooth surfaces of helical gears that enables a favorable bearing contact and a reduced level of vibration is described. Methods for grinding of the helical gears with the new topology are proposed. A TCA (tooth contact analysis) program for simulation of meshing and contact of helical gears with the new topology has been developed. Numerical examples that illustrate the proposed ideas are discussed.
Full Text Available The issue of design and dimensioning of HCR gearing, particularly of the gearings with an internal engagement, it nowadays, especially in the design of hybrid cars drives, highly topical. This kind of gearing has many advantages in operation, but at the same time it is more complicated in stage of its design and load capacity calculation. Authors in this contribution present some results of temperature scuffing research of internal and external HCR gearing. There are given the equations for calculation of warm scuffing resistance of both external and internal HCR gearing derived according to the integral temperature criterion.
Gergel, Sarah E.; Vincent, Amanda C. J.
Locally sustainable resource extraction activities, at times, transform into ecologically detrimental enterprises. Understanding such transitions is a primary challenge for conservation and management of many ecosystems. In marine systems, over-exploitation of small-scale fisheries creates problems such as reduced biodiversity and lower catches. However, long-term documentation of how governance and associated changes in fishing gears may have contributed to such declines is often lacking. Using fisher interviews, we characterized fishing gear dynamics over 60 years (1950–2010) in a coral reef ecosystem in the Philippines subject to changing fishing regulations. In aggregate fishers greatly diversified their use of fishing gears. However, most individual fishers used one or two gears at a time (mean number of fishing gears fishing effort (days per year) was fairly steady over the study period, but cumulative fishing effort by all fishers increased 240%. In particular, we document large increases in total effort by fishers using nets and diving. Other fishing gears experienced less pronounced changes in total effort over time. Fishing intensified through escalating use of non-selective, active, and destructive fishing gears. We also found that policies promoting higher production over sustainability influenced the use of fishing gears, with changes in gear use persisting decades after those same policies were stopped. Our quantitative evidence shows dynamic changes in fishing gear use over time and indicates that gears used in contemporary small-scale fisheries impact oceans more than those used in earlier decades. PMID:29538370
Townsend, D. P.; Zaretsky, E. V.
Surface fatigue tests were conducted on two groups of AISI 9310 spur gears. Both groups were manufactured with standard ground tooth surfaces, with the second group subjected to an additional shot peening process on the gear tooth flanks. The gear pitch diameter was 8.89 cm (3.5 in.). Test conditions were a gear temperature of 350 K (170 F), a maximum Hertz stress of 1.71 billion N/sq m (248,000 psi), and a speed of 10,000 rpm. The shot peened gears exhibited pitting fatigue lives 1.6 times the life of standard gears without shot peening. Residual stress measurements and analysis indicate that the longer fatigue life is the result of the higher compressive stress produced by the shot peening. The life for the shot peened gear was calculated to be 1.5 times that for the plain gear by using the measured residual stress difference for the standard and shot peened gears. The measured residual stress for the shot peened gears was much higher than that for the standard gears.
Townsend, D. P.; Zaretsky, E. V.; Bamberger, E. N.
Tests were conducted at 350 K with three groups of 8.9 cm pitch diameter spur gears made of vacuum-induction melted (VIM), vacuum-arc remelted (VAR), AISI M-50 steel and one group of vacuum-arc remelted (VAR) AISI 9310 steel. The pitting fatigue life of the standard forged and ausforged gears was approximately five times that of the VAR AISI 9310 gears and ten times that of the bending fatigue life of the standard machined VIM-VAR AISI M-50 gears run under identical conditions. There was a slight decrease in the 10-percent life of the ausforged gears from that for the standard forged gears. However, the difference is not statistically significant. The standard machined gears failed primarily by gear tooth fracture while the forged and ausforged VIM-VAR AISI M-50 and the VAR AISI 9310 gears failed primarily by surface pitting fatigue. The ausforged gears had a slightly greater tendency to fail by tooth fracture than the standard forged gears.
Xue, Song; Howard, Ian
This paper presents a new gear dynamic model for flexibly supported gear sets aiming to improve the accuracy of gear fault diagnostic methods. In the model, the operating gear centre distance, which can affect the gear design parameters, like the gear mesh stiffness, has been selected as the iteration criteria because it will significantly deviate from its nominal value for a flexible supported gearset when it is operating. The FEA method was developed for calculation of the gear mesh stiffnesses with varying gear centre distance, which can then be incorporated by iteration into the gear dynamic model. The dynamic simulation results from previous models that neglect the operating gear centre distance change and those from the new model that incorporate the operating gear centre distance change were obtained by numerical integration of the differential equations of motion using the Newmark method. Some common diagnostic tools were utilized to investigate the difference and comparison of the fault diagnostic results between the two models. The results of this paper indicate that the major difference between the two diagnostic results for the cracked tooth exists in the extended duration of the crack event and in changes to the phase modulation of the coherent time synchronous averaged signal even though other notable differences from other diagnostic results can also be observed.
Fang, Suping; Liu, Yongsheng; Wang, Huiyi; Taguchi, Tetsuya; Takeda, Ryuhei
In the precision measurement of involute helical gears, the alignment angle error of a gear axis, which was caused by the assembly error of a gear measuring machine, will affect the measurement accuracy of profile deviation. A model of the involute helical gear is established under the condition that the alignment angle error of the gear axis exists. Based on the measurement theory of profile deviation, without changing the initial measurement method and data process of the gear measuring machine, a compensation method is proposed for the alignment angle error of the gear axis that is included in profile deviation measurement results. Using this method, the alignment angle error of the gear axis can be compensated for precisely. Some experiments that compare the residual alignment angle error of a gear axis after compensation for the initial alignment angle error were performed to verify the accuracy and feasibility of this method. Experimental results show that the residual alignment angle error of a gear axis included in the profile deviation measurement results is decreased by more than 85% after compensation, and this compensation method significantly improves the measurement accuracy of the profile deviation of involute helical gear. (paper)
Qvist Eliasen, Søren; Mortensen, Lars O.; Ulrich, Clara
In the Minidisc project 14 vessels fished under conditions corresponding to free choose of gear. Based on the skippers initial idea of gear adjustment and a subsequent interview 6 months later the experiences of the skippers´ choice of “free” gear, the process for adjusting it and the tools...... for evaluating the efficiency and selectivity are discussed. Only incremental development using elements from previous used gear and other fisheries were found. Gear development took place in an interaction between the skipper and trawl maker, while no research was involved. This indicates that free choice...... of gear (under monitored discard ban) would lead to incremental adjustments. Parts of the fleet would have difficulties in evaluating the gear and subsequently optimise by adjusting. This would leave a need for support for development of evaluation procedures, especially among the small vessels. Radical...
Mohammad Qasim Abdullah
Full Text Available Reduction of noise and vibration in spur gear experimentally by using asymmetric teeth profiles with tip relief was presented. Both of classical (symmetric and asymmetric (with and without tip relief spur gears are used in this work. Gear test rig was constructed to achieve torsional vibration measuring, and two modified cutters are designed and manufactured to achieve tooth profile modifications. First to cut asymmetric gear tooth with pressure angles (14.5o/25 o without tip relief for loaded and unloaded tooth sides respectively, and second to cut asymmetric gear tooth with pressure angles (14.5o/25 o for loaded and unloaded tooth sides respectively with tip relief to achieve best dynamic performance. Dynamic load factor, transmission error and noise level are carried out in this work. Final results showed improvement in dynamic load factor and noise level for asymmetric gear (with and without tip relief compared with classical spur gear .
Townsend, D. P.; Zaretsky, E. V.
Gear endurance tests and rolling-element fatigue tests were conducted to compare the performance of spur gears made from AISI 9310, CBS 600 and modified Vasco X-2 and to compare the pitting fatigue lives of these three materials. Gears manufactured from CBS 600 exhibited lives longer than those manufactured from AISI 9310. However, rolling-element fatigue tests resulted in statistically equivalent lives. Modified Vasco X-2 exhibited statistically equivalent lives to AISI 9310. CBS 600 and modified Vasco X-2 gears exhibited the potential of tooth fracture occurring at a tooth surface fatigue pit. Case carburization of all gear surfaces for the modified Vasco X-2 gears results in fracture at the tips of the gears.
Townsend, D. P.; Zaretsky, E. V.
Tests were conducted with two groups of 8.89-centimeter (3.5-in.) pitch diameter spur gears with standard 20 deg involute profile with tip relief made of CVM Super-Nitralloy (5Ni-2Al) and CVM AISI M-50 at a temperature of 350 K (170 F). Super-Nitralloy gears with tip relief had a life 150 percent that of gears without tip relief. An increased scoring phenomenon was noted with the Super-Nitralloy gears with tip relief. Through-hardened AISI M-50 gears with tip relief failed due to tooth fracture. AISI M-50 gears without tip relief had a life approximately 40 times greater than the AISI M-50 gears with tip relief.
Liang, Xihui; Zuo, Ming J.; Liu, Libin
When there is a single cracked tooth in a planet gear, the cracked tooth is enmeshed for very short time duration in comparison to the total time of a full revolution of the planet gear. The fault symptom generated by the single cracked tooth may be very weak. This study aims to develop a windowing and mapping strategy to interpret the vibration signal of a planetary gear at the tooth level. The fault symptoms generated by a single cracked tooth of the planet gear of interest can be extracted. The health condition of the planet gear can be assessed by comparing the differences among the signals of all teeth of the planet gear. The proposed windowing and mapping strategy is tested with both simulated vibration signals and experimental vibration signals. The tooth signals can be successfully decomposed and a single tooth fault on a planet gear can be effectively detected.
Buchowski, Mary Anne
Faced with the frustration of refereeing when they would rather teach, many educators are looking for alternative ways to deal with conflict in the classroom. This articles discusses the Children's Creative Response to Conflict (CCRC) conflict resolution approach and seeks to dispel some of the prevailing misconceptions about conflict resolution.…
Chang, David C; Cornwell, Edward E; Sutton, Erica R H; Yonas, Michael A; Allen, Fred
In a previous report, enhanced resource commitment at a Level I trauma center was associated with improved outcomes for most major categories of injured patients, except those with gunshot wounds, which disproportionately affected the young (ages 15 to 24 years). We hypothesized that a primary violence-prevention initiative geared toward changing attitudes about interpersonal conflict among at-risk youths can be effective. Between May 2002 and November 2003, 97 youths (mean age 12.6 years) were recruited from one of two Police Athletic League centers in the catchment area of our Level I trauma center. Participant attitudes about interpersonal conflicts were surveyed with six previously validated scales before and after a hospital tour with a video and slide presentation graphically depicting the results of gun violence. Mean differences in scores between pre- and postintervention surveys were assessed. Of the 97 participants, 48 (49.4%) completed the intervention program with both the pre- and postintervention tests, with a mean of 25.8 days between tests. There was a statistically significant reduction in the Beliefs Supporting Aggression scale (mean -0.38 U; 95% CI, -0.23 to -0.54; p < 0.01), and a trend toward reduced Likelihood of Violence (mean -0.17 U; 95% CI, 0.01 to -0.34; p = 0.06). A multidisciplinary violence-prevention outreach program can produce short-term improvement in beliefs supporting aggression among at-risk youth. Longterm impact of this attitude change needs to be examined in future studies.
Conflicts are an integral part of every business-to-business co-operation. Enterprise’s activities in the international markets require from the company to take measures to resolve the conflict so as to prevent the negative impact on relationships and further cooperation. This article adopts the strategic network approach to analyze the conflicts and their impact on relationships in a network operating in a foreign market. Conflicts that occur between the two parties involved in a strategic b...
Cobb, S B
The field of conflict resolution has been focusing on certain implicit postulates related to the nature of three central concepts, namely: communication, conflict, and change. The present paper "undermines" so to speak, these three concepts by demonstrating the positivistic basis the field of conflict resolution features, even though recent contributions challenge such basis. A poststructural perspective on communication, conflict, and change is proposed as an alternative able to generate new tools and techniques for research as well as intervention in conflicts.
Mola Sanna, Bruna; Igual Ayerbe, Blanca
Our sanitary system and our health organizations have to confront the conflicts which have derived from the successive social and sanitary changes which have developed over the most recent decades. These new realities in the health fields oblige the professionals dedicated to them, the administrators of our organizations, the politicians, and society in general, as those who make use of the health services provided, to search for strategies and resources for the prevention, and transformation of those conflicts which can develop due to these situations, having as their final objective to preserve the basic principle of universal health care which is included in our Constitution. For this reason, the authors propose a profile for mediators in the health field, understanding that for mediation to really be useful, and to avoid or reduce improper litigation in our health system, values which belong to the culture of peace should be introduced into the culture of our health organizations. To that end, it is essential to count on not only professional mediators but also on an elenchus of natural mediators and informal mediators.
The aim of this paper was to bring the dialogical and multivoiced dimension of conflict to the fore in the study of how people remember a particular event in the past. Drawing from different case studies, it contains analyses of how subjects identifying with different political actors in the Basq...... with a discussion on the role of history teaching in promoting a more critical, reflexive, and pluralistic way of dealing with memory, and hence with conflict.......The aim of this paper was to bring the dialogical and multivoiced dimension of conflict to the fore in the study of how people remember a particular event in the past. Drawing from different case studies, it contains analyses of how subjects identifying with different political actors in the Basque...... conflict adopted their respective positions, and interpretation of the conflict, and how, in light of same, they reconstruct the failed peace process that took place in 2006 between the terrorist group ETA (Euzkadi ta Azcatasuna, or Basque Country and Freedom in English) and the Spanish government. Results...
Townsend, D. P.; Bamberger, E. N.; Zaretsky, E. V.
Standard forged and ausforged spur gears made of vacuum-induction-melted, consumable-electrode, vacuum-arc-remelted AISI M-50 steel were tested under conditions that produced fatigue pitting. The gears were 8.89 cm (3.5 in.) in pitch diameter and had tip relief. The M-50 standard forged and ausforged test results were compared with each other. They were then compared with results for machined vacuum-arc-remelted AISI 9310 gears tested under identical conditions. Both types of M-50 gears had lives approximately five times that of the 9310 gears. The life at which 10 percent of the M-50 ausforged gears failed was slightly less than that at which the M-50 standard forged gears failed. The ausforged gears had a slightly greater tendency to fail by tooth fracture than did the standard forged gears, most likely because of the better forging and grain flow pattern of standard forged gears.
CDC's Dr. Oliver Morgan discusses how the use of masks and other protective gear impacted whether workers dealing with an outbreak of bird flu in England became sick. The paper is published in the January 2009 issue of CDCâs journal, Emerging Infectious Diseases. Created: 12/29/2008 by Emerging Infectious Diseases. Date Released: 12/29/2008.
Full Text Available The article presents the results of verification of the drive system dynamic model with gear. Tests were carried out on the real object in different operating conditions. For the same assumed conditions were also carried out simulation studies. Comparison of the results obtained from those two series of tests helped determine the suitability of the model and verify the possibility of replacing experimental research by simulations with use of dynamic model.
Full Text Available This paper presents a model for gear pump assembly design realized in Solid Edge V20. The aim is to highlight modelling aspects for solid part components and how to achieve an assembly from several component parts. Can be noted that computer aided design (CAD software can provide multiple options of representing various designed components, assemblies containing up to hundreds of items and part component motion simulation.
CH47/414/100 Evi strom F28 Evistrom 280 Hiller 12E/12ET Hiller FH1100 Hughes 300 Hughes 500/530 CL Hughes AH-64 Kaman SH-2F LHX Robinson R22 Sikorsky S...BMFTI,.. 860.000 DtM DFG 150.000 DM FZG-ACTIVITIES, E.G. TESTS 100.000 DM EVA : GEAR RESEARCH ASSOCIATION OF THE GERMAN INDUSTRY BMFT: FEDERAL MINISTERY
Sagin, A. [Metallurgy Engineering Dept., Technical Univ. of Yildiz, Istanbul (Turkey); Topuz, A. [Chemical and Metallurgical Faculty, Technical Univ. of Yildiz, Istanbul (Turkey)
The investigations presented in this contribution were targeted to replace a gear group made up of SAE 8620 steel in army jeeps with microstructural controlled austempered ductile iron, in order to reduce the manufacturing steps. Furthermore, the vibrations were also expected to decrease, due to the application of austempered ductile iron. The fatigue resistance of unalloyed and Ni alloyed austempered ductile iron have been investigated to see if some improvement as compared to steels with cementite could be achieved. The effect of the austenization heat treatment on the fatigue resistance was studied in metallographic investigations and it turned out that the alloying elements Cu, Ni and Mo have a beneficial effect. For economical reasons, the gears were fabricated of nodular iron containing 3.98% C, 1.89% Si, 0.269% Mn and 0.028% P. Considering the fatigue resistance, a Ni alloyed material with 3.66% C, about 1.81% Si, 0.134% Mn, 0.031% P and 1.51% Ni was chosen. The roundness of the graphites was about 93-100% and 80-85%. The gears were at first produced by austenization at 900 C for 3 hours and then by austempering at 235 C for 2.5 hours. The fatigue tests were performed at the maximum stresses to be expected. (orig.)
Full Text Available The paper presents the results of numerical calculations of stress distributions in the gear micropump body for applications in hydraulic systems, especially in the marine sector. The scope of the study was to determine the most favorable position of bushings and pumping unit in the gear pump body in terms of stress and displacement distribution in the pump housing. Fourteen cases of gear pump bushings and pumping unit locations were analyzed: starting from the symmetrical position relative to the central axis of the pump, up to a position shifted by 2.6 mm towards the suction channel of the pump. The analysis of the obtained calculation results has shown that the most favorable conditions for pump operation are met when the bushings are shifted by 2.2 mm towards the suction channel. In this case the maximal stress was equal to 109 MPa, while the highest displacement was about 15μm. Strength and stiffness criteria in the modernized pump body were satisfied.
Marichal, Graciliano Nicolás; Del Castillo, María Lourdes; López, Jesús; Padrón, Isidro; Artés, Mariano
In this paper, an intelligent scheme for detecting incipient defects in spur gears is presented. In fact, the study has been undertaken to determine these defects in a single propeller system of a small-sized unmanned helicopter. It is important to remark that although the study focused on this particular system, the obtained results could be extended to other systems known as AUVs (Autonomous Unmanned Vehicles), where the usage of polymer gears in the vehicle transmission is frequent. Few studies have been carried out on these kinds of gears. In this paper, an experimental platform has been adapted for the study and several samples have been prepared. Moreover, several vibration signals have been measured and their time-frequency characteristics have been taken as inputs to the diagnostic system. In fact, a diagnostic system based on an artificial intelligence strategy has been devised. Furthermore, techniques based on several paradigms of the Artificial Intelligence (Neural Networks, Fuzzy systems and Genetic Algorithms) have been applied altogether in order to design an efficient fault diagnostic system. A hybrid Genetic Neuro-Fuzzy system has been developed, where it is possible, at the final stage of the learning process, to express the fault diagnostic system as a set of fuzzy rules. Several trials have been carried out and satisfactory results have been achieved.
Graciliano Nicolás Marichal
Full Text Available In this paper, an intelligent scheme for detecting incipient defects in spur gears is presented. In fact, the study has been undertaken to determine these defects in a single propeller system of a small-sized unmanned helicopter. It is important to remark that although the study focused on this particular system, the obtained results could be extended to other systems known as AUVs (Autonomous Unmanned Vehicles, where the usage of polymer gears in the vehicle transmission is frequent. Few studies have been carried out on these kinds of gears. In this paper, an experimental platform has been adapted for the study and several samples have been prepared. Moreover, several vibration signals have been measured and their time-frequency characteristics have been taken as inputs to the diagnostic system. In fact, a diagnostic system based on an artificial intelligence strategy has been devised. Furthermore, techniques based on several paradigms of the Artificial Intelligence (Neural Networks, Fuzzy systems and Genetic Algorithms have been applied altogether in order to design an efficient fault diagnostic system. A hybrid Genetic Neuro-Fuzzy system has been developed, where it is possible, at the final stage of the learning process, to express the fault diagnostic system as a set of fuzzy rules. Several trials have been carried out and satisfactory results have been achieved.
Marichal, Graciliano Nicolás; Del Castillo, María Lourdes; López, Jesús; Padrón, Isidro; Artés, Mariano
In this paper, an intelligent scheme for detecting incipient defects in spur gears is presented. In fact, the study has been undertaken to determine these defects in a single propeller system of a small-sized unmanned helicopter. It is important to remark that although the study focused on this particular system, the obtained results could be extended to other systems known as AUVs (Autonomous Unmanned Vehicles), where the usage of polymer gears in the vehicle transmission is frequent. Few studies have been carried out on these kinds of gears. In this paper, an experimental platform has been adapted for the study and several samples have been prepared. Moreover, several vibration signals have been measured and their time-frequency characteristics have been taken as inputs to the diagnostic system. In fact, a diagnostic system based on an artificial intelligence strategy has been devised. Furthermore, techniques based on several paradigms of the Artificial Intelligence (Neural Networks, Fuzzy systems and Genetic Algorithms) have been applied altogether in order to design an efficient fault diagnostic system. A hybrid Genetic Neuro-Fuzzy system has been developed, where it is possible, at the final stage of the learning process, to express the fault diagnostic system as a set of fuzzy rules. Several trials have been carried out and satisfactory results have been achieved. PMID:27077868
Full Text Available The Geared Turbofan technology is one of the most promising engine configurations to significantly reduce the specific fuel consumption. In this architecture, a power epicyclical gearbox is interposed between the fan and the low pressure spool. Thanks to the gearbox, fan and low pressure spool can turn at different speed, leading to higher engine bypass ratio. Therefore the gearbox efficiency becomes a key parameter for such technology. Further improvement of efficiency can be achieved developing a physical understanding of fluid dynamic losses within the transmission system. These losses are mainly related to viscous effects and they are directly connected to the lubrication method. In this work, the oil injection losses have been studied by means of CFD simulations. A numerical study of a single oil jet impinging on a single high speed gear has been carried out using the VOF method. The aim of this analysis is to evaluate the resistant torque due to the oil jet lubrication, correlating the torque data with the oil-gear interaction phases. URANS calculations have been performed using an adaptive meshing approach, as a way of significantly reducing the simulation costs. A global sensitivity analysis of adopted models has been carried out and a numerical setup has been defined.
Ramírez-Ley, Karla; De Lira-García, Cynthia; Souto-Gallardo, María de las Cruces; Tejeda-López, María Fernanda; Castañeda-González, Lidia Magdalena; Bacardí-Gascón, Montserrat; Jiménez-Cruz, Arturo
Overweight and obesity have dramatically increased in recent years. In 2006, the prevalence of overweight and obesity among 6- to 12-year-old children was 26% in Mexico. Food advertising has shown to be a contributor to childhood obesity. The purpose of this study was to evaluate the frequency and types of food advertisements geared toward children living in Baja California. Two local channels and three national channels, during a period of 7 h on weekday afternoons and 6 h on weekend mornings, were recorded for 7 days. A total of 235 h were recorded and analyzed. A total of 8299 advertisements were registered; 22% were food-related and 50% were geared toward children. The average of food-related advertisements (FRAs) per half an hour was 4, and half of them were geared toward children. During the time that children may be watching television, 50% of all FRAs were potato and corn chips, desserts and cakes, juices, sweetened cereals, candies, cookies, sweetened beverages and fast foods, which comprises a higher percentage of adult-oriented FRA (32 versus 22%). Children are systematically more exposed than adults to advertisements for high-energy-dense foods.
Zhang, Lei; Fu, Zhihong; Yao, Chen; Zang, Gongzheng; Wan, Yue
The flow velocity of the melt in the extruder was simulated by using software Polyflow, and the size of the die channel with the best flow uniformity was obtained. The die profile shape is obtained by reverse design. The length of the shaping section is determined by Ansys transient thermal analysis. According to the simulation results, the design and manufacture of extrusion die of plastic gear and vacuum cooling setting were obtained. The influence of the five process parameters on the precision of the plastic gear were studied by the single factor analysis method, such as the die temperature T, the screw speed R, the die spacing S, the vacuum degree M and the hauling speed V. The optimal combination of process parameters was obtained by using the neural network particle swarm optimization algorithm(T = 197.05 °C, R = 9.04rpm, S = 67mm, M = ‑0.0194MPa). The tooth profile deviation of the extruded plastic gear can reach 9 level of accuracy.
Miklos, I. Zs; Miklos, C. C.; Alic, C. I.; Raţiu, S.
The housing is an important component in the construction of gear reducers, having the role of fixing the relative position of the shafts and toothed wheels. At the same time, the housing takes over, via the bearings, the shaft loads resulting when the toothed wheel is engaging another toothed mechanism (i.e. power transmission through belts or chains), and conveys them to the foundation on which it is anchored. In this regard, in order to ensure the most accurate gearing, a high stiffness of the housing is required. In this paper, we present the computer-aided 3D modelling of the housing (in cast version) of a single stage cylindrical gear reducer, using the Autodesk Inventor Professional software, on the principle of constructive sizing. For the housing resistance calculation, we carried out an analysis using the Autodesk Simulation Mechanical software to apply the finite element method, based on the actual loads, as well as a comparative study of the stress and strain distribution, for several tightening values of the retaining bolts that secure the cover and the foundation housing.
Full Text Available In the continuing shift from engineered solutions towards more holistic methods of managing flood risk, spatial planning has become the primary focus of a conflict between land and water, water and people. In attempting to strike a balance between making space for water and making space for people, compromises are required. Through five case studies in the UK, this paper analyses the effectiveness of Planning Policy Statement 25 (PPS 25 and the processes of negotiation that it promotes. This assessment allows us to draw conclusions on the nature of the compromises this kind of negotiation can achieve and the implications of this for flood risk management. What emerges is that the beneficial impacts of decisions to develop floodplain areas are given a proper hearing and sensible conditions imposed, rather than arguments to prevent such development remaining unchallenged.
The provision of education is affected in many different ways by political and civil unrest and armed conflict. During armed conflict, the lack of adequate financial support for the maintenance of school buildings, supplies and teacher's salaries becomes particularly acute. Other factors include the destruction of school buildings and other infrastructures in time of war, and the targeting of teachers by acts of violence. This paper explores the impact of conflict on the educational opportunities of men and women. Interventions to address the educational needs of children are also discussed. Among these programs are the Oxfam programs in Bhutan, Sri Lanka, Nicaragua, Bosnia, and Eritrea which have provided psychosocial support and human rights education to refugee and displaced women and children through the provision of educational material and by training teachers.
Full Text Available Kashmir has witnessed violent conflict for many years, and India has been one of the main players in this conflict. This study used the method of drawings to assess how this ongoing conflict has shaped the identities of young Muslims in Kashmir. The identities they expressed were compared with those expressed by young Muslims in Delhi. At each location, one group of participants was asked to draw on the theme “Me and my country” while the other group was asked to draw whatever they desired. When allowed to draw what they wished, adolescents in Kashmir drew symbols of regional identity more often and symbols of India less often than adolescents in Delhi. “I dominant” identities were depicted only by the Delhi-based sample. Drawings from Kashmir did not represent high levels of violence or a fractured relationship with the Indian state. Possible reasons have been discussed.
Ma, Zheng; Lin, Chih-Cheng; Tanev, Stoyan
elaborates on the role of culture diversity and geographical dispersion in NPD team conflict. A simulation is conducted where organizations may be regarded as complex systems to affect the team conflict with a variety of influences. The results firstly indicate that there are two dimensions of NPD team......The complexities of new product development (NPD) teams present both opportunities and challenges to organizations. Very few researches have examined the combined effect of culture and geographical dispersion on teams. Especially, the role of distance still remains an open question. This paper...... conflict: stable and unstable dimensions with four elements: task characteristics, group members’ relationship, cultural diversity and geographical dispersion; secondly, there are two phenomena whereby the geographical dispersion influences the NPD team interaction, and the influence between cultural...
Friis, Karsten; Ringsmose, Jens
hostility from theoretical, political, strategic and legal perspectives. In doing so, and in contrast to current literature, cyber-security is analysed through a multidimensional lens, as opposed to being treated solely as a military or criminal issues, for example. The individual chapters map out...... the different scholarly and political positions associated with various key aspects of cyber conflict and seek to answer the following questions: do existing theories provide sufficient answers to the current challenges posed by conflict in cyberspace, and, if not, could alternative approaches be developed......?; how do states and non-state actors make use of cyber-weapons when pursuing strategic and political aims?; and, how does the advent of conflict in cyberspace challenge our established legal framework? By asking important strategic questions on the theoretical, strategic, ethical and legal implications...
van der Linden, Franciscus L. J.
The object of this paper is to present an universal model that describes the gear contact between two gears in a planar environment. The model includes elastic effects between the gear wheels. Using this model it is possible to create arbitrary spur gear con- nections as well as all kinds of epicyclic gearing configurations by supplying the proper external con- straints. The presented model is implementated in the Modelica language and Dymola is used for the simu- lations.
Inalpolat, Murat; Kahraman, Ahmet
In this study, a nonlinear time-varying dynamic model is proposed to predict modulation sidebands of planetary gear sets. This discrete dynamic model includes periodically time-varying gear mesh stiffnesses and the nonlinearities associated with tooth separations. The model uses forms of gear mesh interface excitations that are amplitude and frequency modulated due to a class of gear manufacturing errors to predict dynamic forces at all sun-planet and ring-planet gear meshes. The predicted gear mesh force spectra are shown to exhibit well-defined modulation sidebands at frequencies associated with the rotational speeds of gears relative to the planet carrier. This model is further combined with a previously developed model that accounts for amplitude modulations due to rotation of the carrier to predict acceleration spectra at a fixed position in the planetary transmission housing. Individual contributions of each gear error in the form of amplitude and frequency modulations are illustrated through an example analysis. Comparisons are made to measured spectra to demonstrate the capability of the model in predicting the sidebands of a planetary gear set with gear manufacturing errors and a rotating carrier.
Townsend, Dennis P.; Shimski, John
Spur-gear fatigue tests were conducted with two lubricants using a single lot of consumable-electrode vacuum-melted (CVM) AISI 9310 spur gears. The gears were case carburized and hardened to Rockwell C60. The gear pitch diameter was 8.89 cm. The lot of gears was divided into two groups, each of which was tested with a different lubricant. The test lubricants can be classified as synthetic polyol-ester-based lubricants. One lubricant was 30 percent more viscous that the other. Both lubricants have similar pressure viscosity coefficients. Test conditions included a bulk gear temperature of 350 K, a maximum Hertz stress of 1.71 GPa at the pitch line, and a speed of 10,000 rpm. The surface fatigue life of gears tested with one lubricant was approximately 2.4 times that for gears tested with the other lubricant. The lubricant with the 30 percent higher viscosity gave a calculated elastohydrodynamic (EHD) film thickness that was 20 percent higher than the other lubricant. This increased EHD film thickness is the most probable reason for the improvement in surface fatigue life of gears tested with this lubricant over gears tested with the less viscous lubricant.
Chen, Xinchun; Li, Jia; Lou, Benchao; Shi, Jiang; Yang, Qijun
Current researches have not yet found the effect law of the cutter parameters and machining parameters on the interference in gear slicing, the interference between the cutter and machined gear often happens because the appropriate cutter parameters and machining parameters cannot be set, which reduces the gear machining accuracy. The relative position between the major flank face and edge-sweeping surface, distribution law of the interference area in forming process of edge-sweeping surface, and effect law of relative positions among edge-sweeping surfaces on the interference are studied by graphical analysis. The effect law of the cutter parameters and machining parameters on the interference is found. The effect law shows that the interference in gear slicing can be controlled when the relief angle measured on the top edge and feed of every rotation are chosen respectively larger than 9° and smaller than 0.15 mm/r. An internal helical gear is sliced with the spur slice cutter and the cutter parameters and machining parameters are set based on above the effect law. The machined gear is measured in Gear Measuring Center and the detection result shows that the comprehensive accuracy reaches GB/T Class 7, where some reach GB/T Class 6. The result can meet the gear machining accuracy requirement and shows that the effect law found is valid. The problem of the interference in gear slicing is solved and the gear machining accuracy can be improved.
Chen, Yen Chu; Itagaki, Takayoshi; Takahashi, Hideo; Takahashi, Mikio
Natural materials are focused on the ecological responsibility, all over the world. The rice-hull contains natural silica about 20 wt.%. Therefore, a carbonized rice-hull; Rice-Hull-Silica-Carbon (RHSC) is focused as effective utilization of the discarded rice hull. In this study, test plastic helical gears were made form polyacetal copolymer filled with RHSC powder by injection molding. Test helical gears were operated on endurance test. The bulk temperature and noise of test gears were measured during gears operation. Then, the tooth damage of test gears were investigated by using optical microscope. It is clarified that difference of tooth damage by kind of test gears. Moreover, the transition of gear bulk temperature and noise during operation are investigated. Based on these results, the effect of RHSC powder is discussed. From the discussions, it seems reasonable to conclude : (1) The heat resistance of plastic gear is improved by adding the RHSC powder. (2) The fatigue life of plastic gear is improved by adding suitable amount of the RHSC powder. (3) The sound pressure level of plastic gear is reduced by adding the smaller median grain diameter of RHSC powder.
Hipel, K. W.
The Graph Model for Conflict Resolution (GMCR) is applied to a real-life groundwater contamination dispute to demonstrate how one can realistically model and analyze the controversy in order to obtain an enhanced understanding and strategic insights for permitting one to make informed decisions. This highly divisive conflict is utilized to explain a rich range of inherent capabilities of GMCR, as well as worthwhile avenues for extensions, which make GMCR a truly powerful decision technology for addressing challenging conflict situations. For instance, a flexible preference elicitation method called option prioritization can be employed to obtain the relative preferences of each decision maker (DM) in the dispute over the states or scenarios which can occur, based upon preference statements regarding the options or courses of actions available to the DMs. Solution concepts, reflecting the way a chess player thinks in terms of moves and counter-moves, are defined to mirror the ways humans may behave under conflict, varying from short to long term thinking. After ascertaining the best outcome that a DM can achieve on his or her own in a conflict, coalition analysis algorithms are available to check if a DM can fare even better via cooperating with others. The ability of GMCR to take into account emotions, strength of preference, attitudes, misunderstandings (referred to as hypergames), and uncertain preferences (unknown, fuzzy, grey and probabilistic) greatly broadens its scope of applicability. Techniques for tracing how a conflict can evolve over time from a status quo state to a final specified outcome, as well as how to handle hierarchical structures, such as when a central government interacts with its provinces or states, further enforces the comprehensive nature of GMCR. Within ongoing conflict research mimicking how physical systems are analyzed, methods for inverse engineering of preferences are explained for determining the preferences required by one or
Full Text Available Analytical review of foreign psychological research on the international conflict styles is presented in this article. Intercultural conflict is understood as an interpersonal conflict between representatives of different cultures. The main models describing the intercultural conflict styles are analyzed: the dual concern model, the intercultural conflict styles inventory model, the face negotiation model. The publication provides a brief review of modern studies’ results of behavior predictors in the intercultural conflict; special attention is paid to the analysis of the influence of culture and intercultural communication apprehension on the choice of conflict styles. The importance of assessing the conflict styles effectiveness used in the situation of intercultural interaction is noted. In conclusion, unresolved problems and actual trends in the study of behavior in the intercultural conflict are designated.
Zhang, Ruiliang; Gu, Fengshou; Mansaf, Haram; Wang, Tie; Ball, Andrew D.
Gears are important mechanical components for power transmissions. Tooth wear is one of the most common failure modes, which can present throughout a gear's lifetime. It is significant to accurately monitor gear wear progression in order to take timely predictive maintenances. Motor current signature analysis (MCSA) is an effective and non-intrusive approach which is able to monitor faults from both electrical and mechanical systems. However, little research has been reported in monitoring the gear wear and estimating its severity based on MCSA. This paper presents a novel gear wear monitoring method through a modulation signal bispectrum based motor current signal analysis (MSB-MCSA). For a steady gear transmission, it is inevitable to exist load and speed oscillations due to various errors including wears. These oscillations can induce small modulations in the current signals of the driving motor. MSB is particularly effective in characterising such small modulation signals. Based on these understandings, the monitoring process was implemented based on the current signals from a run-to-failure test of an industrial two stages helical gearbox under a moderate accelerated fatigue process. At the initial operation of the test, MSB analysis results showed that the peak values at the bifrequencies of gear rotations and the power supply can be effective monitoring features for identifying faulty gears and wear severity as they exhibit agreeable changes with gear loads. A monotonically increasing trend established by these features allows a clear indication of the gear wear progression. The dismantle inspection at 477 h of operation, made when one of the monitored features is about 123% higher than its baseline, has found that there are severe scuffing wear marks on a number of tooth surfaces on the driving gear, showing that the gear endures a gradual wear process during its long test operation. Therefore, it is affirmed that the MSB-MSCA approach proposed is reliable
Full Text Available In this paper, a novel longitudinal tooth flank crowning method is proposed by setting the crossed angle between the hob cutter and work gear as a linear function of hob’s traverse feed movement in the gear hobbing process. However, this method makes twisted tooth flanks on the hobbed work gear. Therefore, a variable pressure angle hob cutter is applied to obtain an anti-twist tooth flank of hobbed work gear. A computer simulation example is performed to verify the superiority of the proposed novel hobbing method by comparing topographies of the crowned work gear surfaces hobbed by a standard hob cutter and a variable pressure angle hob cutter.
S. V. Myamlin
Full Text Available Purpose. To determine the dynamic qualities of the main locomotives that characterize safety traffic along straight and curved track sections in the entire range of operational speeds, it is necessary to perform a whole range of studies. One of the necessary conditions for a qualitative improvement of the traction rolling stock of railways is the determination of the parameters of its running gears. Among the issues related to this problem, the important task is to determine the dynamic qualities of locomotives at the design stage, taking into account the selected technical solutions in the design of running gears. At the same time, special attention is paid to the connections of the body with bogie, in particular, using the inclined rods. Methodology. Mathematical modeling is carried out by the method of numerical integration of the equations of the mathematical model of locomotive spatial oscillations to determine the dynamic loading of the mainline locomotive using the software package "Dynamics of Rail Vihicles" ("DYNRAIL". Findings. The research results show that in order to create a simple and reliable design of running gears, which will reduce maintenance and repair costs, will have low initial cost and operating costs for the whole life cycle, high traction force as close as possible to the ultimate force in traction, will make it possible to operate in the multiple traction mode, the designers and scientists should implement scientific and technical solutions. Originality. In accordance with researches authors formed general classification formation of body/bogie connections and the general classification of structures of inclined rod of locomotives. Practical value. Generalization of the results of theoretical, scientific-methodical, experimental studies aimed at further improving the running gears of long-distance locomotives of perspective structures is urgent in improving the rolling stock constructions. The research carried out by
Ferreira, N; Krah, T; Jeong, D C; Kniel, K; Härtig, F; Metz, D; Dietzel, A; Büttgenbach, S
The integration of silicon micro probing systems into conventional gear measuring instruments (GMIs) allows fully automated measurements of external involute micro spur gears of normal modules smaller than 1 mm. This system, based on a silicon microprobe, has been developed and manufactured at the Institute for Microtechnology of the Technische Universität Braunschweig. The microprobe consists of a silicon sensor element and a stylus which is oriented perpendicularly to the sensor. The sensor is fabricated by means of silicon bulk micromachining. Its small dimensions of 6.5 mm × 6.5 mm allow compact mounting in a cartridge to facilitate the integration into a GMI. In this way, tactile measurements of 3D microstructures can be realized. To enable three-dimensional measurements with marginal forces, four Wheatstone bridges are built with diffused piezoresistors on the membrane of the sensor. On the reverse of the membrane, the stylus is glued perpendicularly to the sensor on a boss to transmit the probing forces to the sensor element during measurements. Sphere diameters smaller than 300 µm and shaft lengths of 5 mm as well as measurement forces from 10 µN enable the measurements of 3D microstructures. Such micro probing systems can be integrated into universal coordinate measuring machines and also into GMIs to extend their field of application. Practical measurements were carried out at the Physikalisch-Technische Bundesanstalt by qualifying the microprobes on a calibrated reference sphere to determine their sensitivity and their physical dimensions in volume. Following that, profile and helix measurements were carried out on a gear measurement standard with a module of 1 mm. The comparison of the measurements shows good agreement between the measurement values and the calibrated values. This result is a promising basis for the realization of smaller probe diameters for the tactile measurement of micro gears with smaller modules. (paper)
Csupor, Éva; Kuna, Ágnes; Pintér, Judit Nóra; Kaló, Zsuzsa; Csabai, Márta
Efficient communication, conflict management and cooperation are the key factors of a successful patient care. This study is part of an international comparative research. The aim of this study is to unfold conflicts among healthcare workers. 73 healthcare workers were interviewed using a standardized interview protocol. The in-person interviews used the critical incident method. 30 interviews (15 doctors, 15 nurses) were analysed with the Atlas.ti 7 content analysis software. The sources, types, effects of conflicts and conflict management strategies were investigated. The content analysis unfolded the specificities of conflicts in healthcare based on personal experiences. Organizational hierarchy was a substantial source of conflict, especially among physicians, which originates from implicit rules. As a result of the avoiding conflict management the conflicts remain partly unresolved which has negative individual and group effect. Our conceptual framework helps to develop a proper intervention specific to healthcare. Orv. Hetil., 2017, 158(16), 625-632.
Kesting, Peter; Smolinski, Remigiusz; Speakman, Ian
: the repetitive character of routine, disagreement over the “validity” of the existing routines, disagreement concerning the definition of new targets, and resistance towards change processes. Further the authors point to the inherent tendency to routinize conflict management strategies and the risks...
Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 social interaction, conflict strategy, machine learning REPORT DOCUMENTATION...community. [Hocker and Wilmot, 2013] We fight with our peers over cubicle spaces, with our relatives over what career path to take, with our partners on
However, among the very large diversity of reproductive systems of plants, dioecy gathers all the. *For correspondence. E-mail: firstname.lastname@example.org, email@example.com conditions to give rise to sexual conflict: separate sexes, dif- ferent fitness optima for males and females, and a common genome.
Cecchi, Francesco; Leuveld, Koen; Voors, Maarten
We use data from a street football tournament and a series of lab-in-field experiments in postconflict Sierra Leone to examine the impact of exposure to conflict violence on competitive behavior. We find that football players who experienced more intense exposure to violence are more likely to get a
Inman, Sally; Mc Cormack, Pip; Walker, Sarah
This article discusses some preliminary findings of the English part of a European Commission Fundamental Rights and Citizenship funded project "Children's Voices" (2011-2013) concerned with exploring and understanding children and young people's experiences of interethnic conflict and violence in primary and secondary schools. This is a…
Swart, Henriëtte de; Zwart, J.
Semantic interpretation is not a simple process. When we want to know what a given sentence means, more is needed than just a simple ‘adding up’ of the meanings of the component words. Not only can the words in a sentence interact and conflict with each other, but also with the linguistic and
Kilner, R.M.; Hinde, C.A.
Disputes between parents and their young might seem easy enough to spot in everyday human life, but the notion of a general, evolutionary conflict between offspring and their parents has proved surprisingly slippery (reviewed by Godfray 1995). Nevertheless, today, almost four decades since the
oby 1991; Scott et al. 1998; Adams et al. 2000; Brandvain and Haig 2005), indicating the extent of intralocus conflict in plants. In Arabidopsis thaliana, the imprinted loci are involved in seed provisioning (Scott et al. 1998; Adams et al. 2000), with paternally imprinted genes increasing seed size and maternally imprinted ...
After Vietnam, the term Post Traumatic Stress Disorder (PTSD) entered into our vocabularies. PTSD is centered on the individual both in its definition and approaches to trauma treatment. Yet violent conflict affects not only the individual, but also whole so- cietal structures: communities, families, villages and cities, as well.
Full Text Available This research was basically based on qualitative study. It was the second conflict in Sampang, the rampage which exploded between some people who trying to block the Tajul Muluk’s followers and preventing them from going back to the Pondok Pesantren (Islamic Boarding House of YAPPI in Bangil, Pasuruan. The data in this study was collected using three sorts of data collection techniques: interview, document analysis, and observation. It was done by using the conflict analysis method, from which the writer found out that this second incident appeared in Sampang is manifestation of latent conflict accumulation which is actually personal conflict complicated by some religious issues. The conflict is to be resolved by using both bureaucracy and cultural approaches.
Full Text Available This study aims to identify and analyze the cultural conflicts between the main characters in the novel Not Without my Daughter (NW. The analysis was carried out through the following process. The first procedure related to problems of classification i.e. cross cultural conflicts. The next phase of data analysis related to the colletion data of cross cultural conflicts in NW. The last phase is presentation the result of the analysis that had been conducted in this research. Having analyzed the data, the researcher concludes that cultural conflicts occured in NW because of stereotype, prejudice, and ethnocentrism. Cultural conflicts can be prevented if we increase our awareness of our own attitudes and learn to be sensitive to cross-cultural differences. However, if we develop intercultural sensitivity, it does not mean that we need to lose our cultural identities-but rather that we recognize cultural influences within ourselves and within others.
Dignath, David; Kiesel, Andrea; Eder, Andreas B
Conflict processing is assumed to serve two crucial, yet distinct functions: Regarding task performance, control is adjusted to overcome the conflict. Regarding task choice, control is harnessed to bias decision making away from the source of conflict. Despite recent theoretical progress, until now two lines of research addressed these conflict-management strategies independently of each other. In this research, we used a voluntary task-switching paradigm in combination with response interference tasks to study both strategies in concert. In Experiment 1, participants chose between two univalent tasks on each trial. Switch rates increased following conflict trials, indicating avoidance of conflict. Furthermore, congruency effects in reaction times and error rates were reduced following conflict trials, demonstrating conflict adjustment. In Experiment 2, we used bivalent instead of univalent stimuli. Conflict adjustment in task performance was unaffected by this manipulation, but conflict avoidance was not observed. Instead, task switches were reduced after conflict trials. In Experiment 3, we used tasks comprising univalent or bivalent stimuli. Only tasks with univalent revealed conflict avoidance, whereas conflict adjustment was found for all tasks. On the basis of established theories of cognitive control, an integrative process model is described that can account for flexible conflict management. (c) 2015 APA, all rights reserved.
Sobek, M.; Baier, A.; Grabowski, Ł.
Transferring both rotational and translational movements in systems used in the automotive industry is a very important and complex issue. In addition, the situation becomes much more difficult and complicated when the design of the transition system requires a high precision of operation as well as a well definite and long operating life. Such requirements are imposed on all components of today’s motor vehicles. However, particular attention is paid to the elements that directly or indirectly affect the safety of persons traveling in the vehicle. Such components are undoubtedly components included as parts of the steering system of the vehicle. Power steering systems have been present in motor vehicles for more than a century. They go through continuous metamorphosis and they are getting better and better. Current power steering systems are based on an electric motor and some kind of transmission. Depending on the position of the drive relative to the steering column, different configurations of the transmission are used. This article will cover issues related to tests of power steering gearing using a worm drive. The worm drive is a very specific example of a propulsion system that uses twisted axles. Normally, in this type of transition you can find two gear units with the axis mounted with a 90° angle between. The components of the worm drive are a worm and a worm gear, also called a worm wheel. In terms of the geometrical form, the worm resembles a helical spur gear. The shape of the worm is similar to the shape of a screw with a trapezoidal thread. A correct matching of these two components ensures proper operation of the entire transmission. Incorrect positioning of the components in relation to each other can significantly reduce the lifetime of the drive unit, and also lead to abnormal work, eg by raising the noise level. This article describes a test method of finding the appropriate distance between the axles of both worm drive units by testing the
Ni, Xin-lei; Yin, Hai-qing; Liu, Lin; Yi, Shan-jie; Qu, Xuan-hui
Micro powder injection molding (μPIM) was investigated for possible mass production of micro-components at relatively low cost. However, scaling down to such a level produces challenges in injection molding and debinding. Micro gears were fabricated by μPIM from in-house feedstock. The effect of injection speed and injection pressure on the replication of the micro gear cavity was investigated. Solvent debinding and thermal debinding processes were discussed. The results show that micro gears can be successfully fabricated under the injection pressure of 70 MPa and the 60% injection speed. Either too low or too high injection speed can cause incomplete filling of micro gears. The same is the case with too low injection pressure. Too high injection pressure can bring cracks. Solvent debinding of micro gears was performed in a mixture of petroleum ether and ethanol. Subsequently, micro gears were successfully debound by a multistep heating schedule.
Full Text Available The rapidly advancing technological development leads to designing and researching a new multi- output gear mechanism. The investigated new double-output gear mechanism has two output coaxial shafts located against the input shaft on the other side of the gearbox. The gear mechanism achieves high gear ratios. Its limiting structural node is the output stage, to which the gears belong. The problem is addressed through the analysis of the stress resistance of tooth flanks in contact and bending. The content of the paper is a comparison of analytical computations with the modal analysis on the model. We expect that new findings will be beneficial for further optimization of the gear mechanism.
Full Text Available The dynamic behavior of a single-stage planetary gear set with helical gears of multishaft automotive automatic transmissions has been studied, in which one component of the planetary gear set is imposed by additional external vertical and axial loading from countershaft gear pair in addition to the moment. Under these combined loading conditions, the contributions of the deflections of the ring gear and the carrier cannot be neglected. A three-dimensional nonlinear time-variant dynamic model considering not only the transverse, torsional, axial, and rotational motions of the gears but also the elasticity of the mounted shafts has been developed by combining the lumped parameter method with finite element method. The natural modes and the forced vibration responses due to static transmission errors have been obtained. The proposed dynamic model is employed to describe the effects of the combined external loading condition and positioning on the dynamic behavior of a four-planet system.
Full Text Available In this paper, a dynamic model for a magnetic planetary gear drive is proposed. Based on the model, the dynamic equations for the magnetic planetary gear drive are given. From the magnetic meshing forces and torques between the elements for the drive system, the tangent and radial magnetic meshing stiffness is obtained. Using these equations, the natural frequencies and the modes of the magnetic planetary gear drive are investigated. The sensitivity of the natural frequencies to the system parameters is discussed. Results show that the pole pair number and the air gap have obvious effects on the natural frequencies. For the planetary gear number larger than two, the vibrations of the drive system include the torsion mode of the center elements, the translation mode of the center elements, and the planet modes. For the planetary gear number equal to two, the planet mode does not occur, the crown mode and the sun gear mode occur.
Dempsey, Paula J.; Handschuh, Robert F.; Delgado, Irebert, R.
The objective of this study was to illustrate the importance of combining Health Usage Monitoring Systems (HUMS) data with usage monitoring system data when detecting rotorcraft transmission health. Three gear sets were tested in the NASA Glenn Spiral Bevel Gear Fatigue Rig. Damage was initiated and progressed on the gear and pinion teeth. Damage progression was measured by debris generation and documented with inspection photos at varying torque values. A contact fatigue analysis was applied to the gear design indicating the effect temperature, load and reliability had on gear life. Results of this study illustrated the benefits of combining HUMS data and actual usage data to indicate progression of damage for spiral bevel gears.