The rather drastic changes in the Cataloguing Rules of University College London, which were described in Vol. 12, no. 2 of this journal, published in June 1956, soon became…
Abstract
The rather drastic changes in the Cataloguing Rules of University College London, which were described in Vol. 12, no. 2 of this journal, published in June 1956, soon became accepted routine to the inconvenience of no one, so far as is known, except of the cataloguers whose task it was to make the necessary adjustments and to recatalogue small batches of cards from time to time. This inconvenience was more than compensated by the comparative simplicity of headings for both main and subsidiary entries, and by a reduction in the number of added entries needed.
Man has been seeking an ideal existence for a very long time. In this existence, justice, love, and peace are no longer words, but actual experiences. How ever, with the American…
Abstract
Man has been seeking an ideal existence for a very long time. In this existence, justice, love, and peace are no longer words, but actual experiences. How ever, with the American preemptive invasion and occupation of Afghanistan and Iraq and the subsequent prisoner abuse, such an existence seems to be farther and farther away from reality. The purpose of this work is to stop this dangerous trend by promoting justice, love, and peace through a change of the paradigm that is inconsistent with justice, love, and peace. The strong paradigm that created the strong nation like the U.S. and the strong man like George W. Bush have been the culprit, rather than the contributor, of the above three universal ideals. Thus, rather than justice, love, and peace, the strong paradigm resulted in in justice, hatred, and violence. In order to remove these three and related evils, what the world needs in the beginning of the third millenium is the weak paradigm. Through the acceptance of the latter paradigm, the golden mean or middle paradigm can be formulated, which is a synergy of the weak and the strong paradigm. In order to understand properly the meaning of these paradigms, however, some digression appears necessary.
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Erin Pullen, Brea L. Perry and Gerardo Maupome
Latinos in the United States have poor outcomes for periodontal and dental health. However, a detailed description of the mechanisms driving these patterns has only recently…
Abstract
Latinos in the United States have poor outcomes for periodontal and dental health. However, a detailed description of the mechanisms driving these patterns has only recently started to be addressed in the literature. In the current study, we explore relationships between individual-level characteristics of Mexican immigrants, properties of their networks, and experiences of dental problems. Specifically, using data from an urban community of Mexican immigrants to the American Midwest (n = 332), this study examines how characteristics of oral health matters (OHM) discussion networks and individual-level sociodemographic characteristics are associated with four adverse oral health outcomes. The results provide strong support for relationships between immigrants’ network characteristics and dental problems. We find that people with more dental problems talk about these issues more frequently with network ties. Conversely, stronger relationships with OHM discussion networks, as measured by mean closeness, are predictive of fewer dental problems. In addition, we identify a link between perceptions of alters’ knowledge about teeth, mouth, and gums and egos reporting better oral health outcomes. The observed patterns are suggestive of mechanisms of social influence that are well replicated in the social, medical, and public health literatures, but that have seldom been empirically tested in the domain of oral health. Though preliminary, our findings suggest a potential explanatory role for social networks in some of the most important questions and problems in oral health disparities research. In all, our findings suggest that social network members are active participants in the management and response to oral health problems in this immigrant group and should be considered an important factor in the development and course of diseases.
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Man has been seeking an ideal existence for a very long time. In this existence, justice, love, and peace are no longer words, but actual experiences. How ever, with the American…
Abstract
Man has been seeking an ideal existence for a very long time. In this existence, justice, love, and peace are no longer words, but actual experiences. How ever, with the American preemptive invasion and occupation of Afghanistan and Iraq and the subsequent prisoner abuse, such an existence seems to be farther and farther away from reality. The purpose of this work is to stop this dangerous trend by promoting justice, love, and peace through a change of the paradigm that is inconsistent with justice, love, and peace. The strong paradigm that created the strong nation like the U.S. and the strong man like George W. Bush have been the culprit, rather than the contributor, of the above three universal ideals. Thus, rather than justice, love, and peace, the strong paradigm resulted in in justice, hatred, and violence. In order to remove these three and related evils, what the world needs in the beginning of the third millenium is the weak paradigm. Through the acceptance of the latter paradigm, the golden mean or middle paradigm can be formulated, which is a synergy of the weak and the strong paradigm. In order to understand properly the meaning of these paradigms, however, some digression appears necessary.
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Wenguang Zhou, Rupeng Zhu, Fengxia Lu, Wenzheng Liu and Jingjing Wang
This study aims to research the time-varying mesh stiffness (TVMS) model for orthogonal face gear drives considering elastohydrodynamic lubrication (EHL) and provide a theoretical…
Abstract
Purpose
This study aims to research the time-varying mesh stiffness (TVMS) model for orthogonal face gear drives considering elastohydrodynamic lubrication (EHL) and provide a theoretical basis for understanding the dynamic characteristics of face gear drives.
Design/methodology/approach
Considering EHL, a novel model is proposed to calculate the TVMS of orthogonal face gears using the deformation compatibility condition. First, the tooth surface equations of orthogonal face gears are derived according to the tooth surface generation principle. Then, the oil film thickness on the tooth surface of face gears is obtained by solving the governing equations of EHL. Furthermore, the proposed model is used to calculate the TVMS of face gears along the mesh cycle and is verified. Finally, the effects of module, tooth number of shaper cutter and pressure angle on mesh stiffness are analyzed.
Findings
The results indicate that when the contact ratio is greater than 1 and less than or equal to 2, the TVMS of face gears exhibits a phenomenon of double-single tooth alternating meshing where sudden changes occur. As the module increases, the overall mesh stiffness of face gears increases, and the magnitude of the sudden change at the moment of single-double tooth alternating meshing gradually increases. As the tooth number of shaper cutter and pressure angle increase, so does the TVMS of face gears. When the effect of oil film is considered, the calculated TVMS of face gears slightly increases overall and the increase in average oil film thickness leads to a rise in the TVMS. This study provides a theoretical basis for understanding the dynamic characteristics of face gear drives.
Originality/value
This study’s originality and value lie in its comprehensive approach, which includes conducting analysis based on loaded tooth contact, considering the influence of elastohydrodynamic lubrication, proposing a novel analytical–finite–element model, calculating TVMS of face gears, verifying the proposed model and analyzing the effects of typical structural parameters and oil film thickness.
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Introduces papers from this area of expertise from the ISEF 1999 Proceedings. States the goal herein is one of identifying devices or systems able to provide prescribed…
Abstract
Introduces papers from this area of expertise from the ISEF 1999 Proceedings. States the goal herein is one of identifying devices or systems able to provide prescribed performance. Notes that 18 papers from the Symposium are grouped in the area of automated optimal design. Describes the main challenges that condition computational electromagnetism’s future development. Concludes by itemizing the range of applications from small activators to optimization of induction heating systems in this third chapter.
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Nan Gao, Shiyu Wang and Muhammad Asad Ur Rehman Bajwa
Gear transmissions are widely utilized in practice. This paper aims to uncouple the crack feature from the cracked time-varying mesh stiffness (TVMS) and investigate the effects…
Abstract
Purpose
Gear transmissions are widely utilized in practice. This paper aims to uncouple the crack feature from the cracked time-varying mesh stiffness (TVMS) and investigate the effects of the crack on the nonlinear dynamics of a spur gear pair.
Design/methodology/approach
An approximate method to simulate the cracked TVMS is proposed by using an amplitude modulation function. The ratio of mesh stiffness loss is introduced to estimate the TVMS with different crack depths and angles. The dynamic responses are obtained by solving a torsional model which takes the non-loaded static transmission error, the backlash and the cracked TVMS into account. By using the bifurcation diagram, the largest Lyapunov exponent (LLE) and dynamic mesh force, the influences of crack on nonlinear behaviors are examined. The dynamic characteristics are identified from the phase diagram, Poincaré map, dynamic mesh force, time series and FFT spectra.
Findings
The comparison between the healthy and cracked gear pairs indicates that the crack affects the system motions, such as the obvious changes of impact force and unpredictable instability. Besides, the additive and difference combination frequencies can be found in periodic-1 and -2 motions, but they are covered in periodic-3 and chaotic motions. Deeper crack is an important determinant of the nonlinear behaviors at a higher speed.
Originality/value
The research provides an interesting perspective on cracked TVMS and reveals the connection between crack and nonlinear behaviors of the gear pairs.
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Junguo Wang, Zhaoyuan Yao, M.F. Hassan and Yongxiang Zhao
The paper is devoted to presenting a systematic investigation on the mechanical model and nonlinear dynamic characteristics of spur gear system with and without input shaft crack.
Abstract
Purpose
The paper is devoted to presenting a systematic investigation on the mechanical model and nonlinear dynamic characteristics of spur gear system with and without input shaft crack.
Design/methodology/approach
Considering the backlash, load-distribution, time-varying meshing stiffness and sliding friction, the modelling of a 5DOF gear system is proposed. Likewise, stiffness and damping models under elastohydrodynamic lubrication are developed, and sliding friction between gear pair is also outlined. In particular, a cracked input shaft which affects the support stiffness is presented, and breathing crack in keyway is adopted. On this basis, the dynamic responses of a gear system with and without input shaft crack are examined using numerical method, and some classical response diagrams are given, illustrating the effect of the important parameters on the gear system.
Findings
Dynamic simulation demonstrates that there exist periodic, quasi-periodic and chaotic motions in the gear system, and rational speed of the gear pair has noteworthy effects on vibration characteristic. Besides, comparison between healthy and cracked condition of input shaft indicates that occurring of crack convert periodic motion to quasi-periodic or chaotic motion.
Originality/value
The results give an understanding of the operating conditions under which undesirable dynamic behavior occurs, and provide some useful information to design and diagnose such gear system with crack fault.
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Those who move among the people with their eyes open will not doubt that the number of non‐smokers is increasing, but mostly among older adults. Sales of cigarettes, despite the…
Abstract
Those who move among the people with their eyes open will not doubt that the number of non‐smokers is increasing, but mostly among older adults. Sales of cigarettes, despite the ban on advertising and the grim warning printed on packets, do not reflect this however, which can only mean that those who still smoke are the heavy smokers. This is a bad sign; as is the fact that youngsters, including a high percentage of those at school, openly flaunt the habit. The offence of using tobacco or any other smoking mixture or snuff while handling food or in any food room in which there is open food (Reg. 10(e)), remains one of the common causes of prosecutions under the Food Hygiene Regulations; it has not diminished over the years. The commonest offenders are men and especially those in the butchery trade, fishmongers and stall‐holders, but, here again, to those who move around, the habit seems fairely widespread. Parts of cigarettes continue to be a common finding especially in bread and flour confectionery, but also in fresh meat, indicating that an offence has been committed, and only a few of the offenders end up in court. Our purpose in returning to the subject of smoking, however, is not to relate it to food hygiene but to discuss measures of control being suggested by the Government now that advertising bans and printed health warnings have patently failed to achieve their object.
Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines;…
Abstract
Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines; reluctance motors; PM motors; transformers and reactors; and special problems and applications. Debates all of these in great detail and itemizes each with greater in‐depth discussion of the various technical applications and areas. Concludes that the recommendations made should be adhered to.