bluuebunny/crossref_metadata_2025 huggingface dataset:
The HPV Vaccine: Framing the Arguments FOR and AGAINST Mandatory Vaccination of All Middle School Girls
Authors: Vamos Cheryl A. , McDermott Robert J. , Daley Ellen M.
Published: May 2008

Background:  Human papillomavirus (HPV), the virus responsible for cervical cancer, is the most common viral sexually transmitted infection in the United States. A vaccine was approved in 2006 that is effective in preventing the types of HPV responsible for 70% of cervical cancers and 90% of genital warts. Proposals for routine and mandatory HPV vaccination of girls have become sources of controversy for parents of school‐aged youth, legislators, members of the medical community, and the public at large.

Methods:  The purpose of this article was to articulate the arguments used by advocates who either oppose or endorse routine, mandatory administration of the vaccine to school‐aged girls, thereby assisting school health personnel in being effective participants in framing the relevant issues.

Results:  Controversy is grounded in moral, religious, political, economic, and sociocultural arguments including whether concerns that the vaccine increases sexual risk taking, sends mixed messages about abstaining from sexual intercourse, usurps parental authority, and increases the potential for development of new health disparities are offset by the value of administering a cost‐effective, age‐appropriate public health measure targeting a life‐threatening problem.

Conclusions:  Careful consideration of the medical evidence and public health implications is critical but understanding the context of the debate is no less important to the task of responding to public concerns. School health personnel have a role in the discussion about HPV immunization. Being able to articulate the arguments presented herein can help authorities’ responsiveness to parents and community groups as the dialogue about this particular health issue evolves further.
Physical Activity Behaviors and Emotional Self‐Efficacy: Is There a Relationship for Adolescents?
Authors: Valois Robert F. , Umstattd M. Renée , Zullig Keith J. , Paxton Raheem J.
Published: May 2008

Background:  This study explored relationships between physical activity (PA) behaviors and emotional self‐efficacy (ESE) in a statewide sample of public high school adolescents in South Carolina (n = 3836).

Methods:  The Center for Disease Control Youth Risk Behavior Survey PA items and an adolescent ESE scale were used. Logistic regression analyses and multivariate models constructed separately, revealed significant race by gender findings.

Results:  Results suggest that reduced vigorous PA (past 7 days), moderate PA (past 7 days), strengthening/toning exercises (past 7 days), and playing on sport teams (past 12 months) were associated (p ≤ .05) with reduced ESE for specific race/gender groups.

Conclusions:  Results have implications for school‐ and community‐based mental health services and PA programs for adolescents. Measures of ESE as a component of comprehensive assessments of adolescent mental health and PA behaviors in fieldwork, research, and program‐evaluation efforts should be considered.
Factors Influencing Openness to Future Smoking Among Nonsmoking Adolescents*
Authors: Seo Dong‐Chul , Torabi Mohammad R. , Weaver Amy E.
Published: May 2008

Background:  To investigate the correlates of youth tobacco use in terms of nonsmoking adolescents’ openness to future smoking, a secondary analysis of the 2000 and 2004 Indiana Youth Tobacco Survey (IYTS) was conducted.

Methods:  A representative sample of 1416 public high school students in grades 9‐12 and 1516 public middle school students in grades 6‐8 (71.44% and 72.53% response rates, respectively) were surveyed in 2000, and 3433 public high school students and 1990 public middle school students (63.04% and 65.44% response rates, respectively) were surveyed in 2004.

Results:  Seventy‐four percent of students in 2000 were not open to future smoking and 77% were not open in 2004. The adolescent cohort in 2004 became more exposed to antitobacco messages and less exposed to protobacco messages and environmental tobacco smoke (ETS) compared with their counterpart in 2000. Whereas gender, grade, race/ethnicity, and exposure to antitobacco messages were insignificant predictors for openness to future smoking, exposure to ETS either in homes or in cars was a strong predictor for openness to future smoking (the higher the exposure to ETS, the more open to future smoking) in both unadjusted and adjusted multivariate models. Exposure to protobacco messages had a greater effect on openness to future smoking than exposure to antitobacco messages. The rate of transition from openness to future smoking to tobacco use initiation is higher among white adolescents than among minority adolescents.

Conclusions:  More efforts should be made to reduce adolescents’ exposure to ETS and protobacco messages.
Prevalence of Tobacco Use Among Students Aged 13‐15 Years in Health Ministers’ Council/Gulf Cooperation Council Member States, 2001‐2004
Authors: Moh’d Al‐Mulla Ahmad , Abdou Helmy Sahar , Al‐Lawati Jawad , Al Nasser Sami , Ali Abdel Rahman Salah , Almutawa Ayesha , Abi Saab Bassam , Al‐Bedah Abdullah Mohammed , Al‐Rabeah Abdullah Mohamed , Ali Bahaj Ahmed , El‐Awa Fatimah , Warren Charles W. , Jones Nathan R. , Asma Samira
Published: May 2008

Background: This article examines differences and similarities in adolescent tobacco use among Member States of the Health Ministers’ Council for the Gulf Cooperation Council (HMC/GCC) using Global Youth Tobacco Survey (GYTS) data.

Methods: Nationally representative samples of students in grades associated with ages 13‐15 in Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, United Arab Emirates, and Yemen. Schools were selected proportional to enrollment size, classes were randomly selected within participating schools, and all students in selected classes were eligible to participate.

Results: GYTS results confirmed that boys are significantly more likely than girls to smoke cigarettes or use shisha (water pipe). Students had higher rates of tobacco use than adults in Bahrain, Oman, and United Arab Emirates. For boys and girls, shisha use was higher than cigarette smoking in almost all countries. Susceptibility to initiate smoking among never smokers was higher than current cigarette smoking in all countries. Exposure to secondhand smoke in public places was greater than 30%, direct protobacco advertising exposure was greater than 70% on billboards and in newspapers, and more than 10% of students were influenced by indirect advertising. Finally, less than half of the students were taught in school about the dangers of tobacco use in the past year.

Conclusions: For boys and girls, high prevalence of cigarette smoking, high prevalence of shisha use, and high susceptibility of never smokers to initiate smoking in the next year are troubling indicators for the future of chronic disease and tobacco‐related mortality in the Member States of the HMC/GCC.
Cognitivism and the Arts
Authors: Gibson John
Published: May 2008

Cognitivism in respect to the arts refers to a constellation of positions that share in common the idea that artworks often bear, in addition to aesthetic value, a significant kind of cognitive value. In this paper I concentrate on three things: (i) the challenge of understanding exactly what one must do if one wishes to defend a cognitivist view of the arts; (ii) common anti‐cognitivist arguments; and (iii) promising recent attempts to defend cognitivism.
Virtue Epistemology
Authors: Battaly Heather
Published: May 2008

What are the qualities of an excellent thinker? A growing new field, virtue epistemology, answers this question.Section Idistinguishes virtue epistemology from belief‐based epistemology.Section IIexplains the two primary accounts of intellectual virtue: virtue‐reliabilism and virtue‐responsibilism. Virtue‐reliabilists claim that the virtues are stable reliable faculties, like vision. Virtue‐responsibilists claim that they are acquired character traits, like open‐mindedness.Section IIIevaluates progress and problems with respect to three key projects: explaining low‐grade knowledge, high‐grade knowledge, and the individual intellectual virtues.
Supervenience in Metaphysics
Authors: Leuenberger Stephan
Published: May 2008

Supervenience is a topic‐neutral, broadly logical relation between classes of properties or facts. In a slogan, A supervenes on B if and only if there cannot be an A‐difference without a B‐difference. The first part of this paper considers different ways in which that slogan has been cashed out. The second part discusses applications of concepts of supervenience, focussing on the question whether they may provide an explication of determination theses such as physicalism.
The basis of the remoteness rule in contract
Authors: Robertson Andrew
Published: May 2008

There is increasing support in the contract literature for the view that the remoteness rule is essentially concerned with identifying an implicit allocation of risk made by the contracting parties. This paper argues that the remoteness doctrine is more accurately seen as a method by which the courts allocate risks which the contracting parties have failed to allocate, rather than an interpretative rule. Through analysis of the principles and their application in the recent case-law in England, Canada and Australia, the paper shows that the identification of an implicit allocation of risk does not and cannot determine remoteness cases in contract. The justice of the remoteness rule is not based on the notion that the defendant undertook responsibility for the risk in question, but on a concern that the defendant should have a reasonable opportunity to consider the risks that might arise from breach and take action to avoid them.
Effect of Free‐SH Containing Compounds on Allyl Isothiocyanate Antimicrobial Activity against Escherichia coli O157:H7
Authors: Luciano F.B. , Hosseinian F.S. , Beta T. , Holley R.A.
Published: May 2008

ABSTRACT:  Escherichia coli O157:H7 contamination is a significant meat safety issue in many countries. Allyl isothiocyanate (AIT) is a natural compound found to limit the survival of E. coli O157:H7 and other pathogens in meat and meat products. In the present study, it was found that glutathione and cysteine naturally present in meat can interfere with AIT antimicrobial activity. Spectroscopy, HPLC, and LC‐MS were used to confirm that glutathione was able to react with AIT and formed a conjugate with no or low bactericidal activity against the tested organisms. The same reaction also occurred at pH values of 4.9 and 5.8 at 25 and 4 °C, respectively, which broadly represent storage conditions in raw beef (pH 5.8) and during fermented sausage (pH 4.9) manufacture. Reactions observed help to explain reduction in antimicrobial potency of AIT in food (meat) systems.
Probiotic Pre‐treatment Reduces Gliclazide Permeation (ex vivo) in Healthy Rats but Increases It in Diabetic Rats to the Level Seen in Untreated Healthy Rats
Authors: Al‐Salami Hani , Butt Grant , Tucker Ian , Skrbic Ranko , Golocorbin‐Kon Svetlana , Mikov Momir
Published: May 2008

Aim.  To investigate the influence of probiotic pre‐treatment on the permeation of the antidiabetic drug gliclazide in healthy and diabetic rats.

Methods.  Wistar rats (age 2–3 months, weight 350 ± 50 g) were randomly allocated into one of 4 groups (N = 16 each group): healthy control, healthy probiotic, diabetic control, and diabetic probiotic. Probiotics (75 mg/kg, equal quantities of Lactobacillus acidophilus, Bifidobacterium lactis, and Lactobacillus rhamnosus) were administered twice a day for three days to the appropriate groups after diabetes had been induced with alloxan i.v. 30 mg/kg. Rats were sacrificed, ileal tissues mounted in Ussing chambers and gliclazide (200 µg/mL) was administered for the measurement of the mucosal to serosal absorption Jss(MtoS) and serosal to mucosal secretion Jss(StoM) of gliclazide.

Results.  Treatment of healthy rats with probiotics reduced Jss(MtoS) of gliclazide from 1.2 ± 0.3 to 0.3 ± 0.1 µg/min/cm2 (P < 0.01) and increased Jss(StoM) from 0.6 ± 0.1 to 1.4 ± 0.3 (P < 0.01) resulting in net secretion while, in diabetic tissues, treatment with probiotics increased both Jss(MtoS) and Jss(StoM) fluxes of gliclazide to the comparable levels of healthy tissues resulting in net absorption.

Discussion.  In healthy rats, the reduction in Jss(MtoS) after probiotics administration could be explained by the production of bacterial metabolites that upregulate the mucosal efflux drug transporters Mrp2 that control gliclazide transport. In diabetic rats, the restored fluxes of gliclazide after probiotic treatment, suggests the normalization of the functionality of the drug transporters resulting in a net absorption.

Conclusion.  Probiotics may alter gliclazide transport across rat ileal tissue studied ex vivo.
Novel methods for the design and evaluation of marine protected areas in offshore waters
Authors: Leathwick John , Moilanen Atte , Francis Malcolm , Elith Jane , Taylor Paul , Julian Kathryn , Hastie Trevor , Duffy Clinton
Published: May 2008

There is strong international agreement on the need for marine protected areas to reverse pervasive human impacts on the oceans' biodiversity. However, their implementation is often hampered both by legal difficulties in defining reserves in international waters and the patchy nature of data in many offshore waters. We demonstrate the use of recent advances in statistical learning and conservation prioritization to produce MPA scenarios with varying costs and benefits for New Zealand's Exclusive Economic Zone, based on the analyses of distributions of 96 demersal fish species. MPAs based on our most cost‐effective scenario would deliver conservation benefits nearly 2.5 times greater than those from equivalent‐sized areas recently implemented at the request of fishers, and at lower cost to them. Such results demonstrate the power of quantitative, knowledge‐based prioritization approaches, which can be applied at high resolution and at oceanic scales.
U.S. drowning in unidentified fishes: Scope, implications, and regulation of live fish import
Authors: Smith Katherine F. , Behrens Michael D. , Max Lisa M. , Daszak Peter
Published: May 2008

More than half a million shipments and over one billion live animals were imported to the United States since 2000. The majority of these were aquatic organisms, including approximately 1.1 billion fishes. Imported fishes are a major source of revenue for the pet industry and aquaculture, but can be a nuisance if they escape or are released into the wild. Over 200 fish species have been introduced to the United States following importation, many of which threaten ecosystems and infrastructure. Although fishes constitute the majority of animal imports, they receive minimal attention from regulatory agencies. Moreover, poor record keeping at ports make it impossible to assess the diversity of fishes imported, making species‐specific risk analysis and prevention programs difficult. As a global leader in wildlife trade, the United States is well positioned to set standards that promote safe and responsible trade practices. To date, the nation has languished, though there are mechanisms for improvement.
Investigation of Granular Damping in Transient Vibrations Using Hilbert Transform Based Technique
Authors: Fang X. , Luo H. , Tang J.
Published: May 2008

Granular damping results from a combination of energy dissipation mechanisms including the impact and the friction between the vibrating structure and granules and among the granules. Although simple in concept, granular damping is very complicated and its performance depends on a number of factors, such as vibration level, granular material properties, packing ratio, etc. In this study, free vibration experiments are conducted on a cantilevered beam incorporated with granular damping. A signal analysis approach based on the Hilbert transform (HT) is then employed to identify the nonlinear damping characteristics from the acquired responses, such as the dependency of the natural frequency and damping ratio on the vibration level. This HT based analysis can produce an effective temporal-frequency amplitude∕energy analysis, which provides us with physical insights of the nonlinear transient response. A direct comparison between the granular damping and the impact damping (with single impactor to dissipate vibratory energy) is performed to highlight the difference between these two and the advantages of granular damping. Finally, the validity of the proposed approach is also examined by the successful prediction of vibration response using the extracted granular damping characteristics.
A Constrained Lagrange Formulation of Multilink Planar Flexible Manipulator
Authors: Vakil M. , Fotouhi R. , Nikiforuk P. N. , Salmasi H.
Published: May 2008

In this article, the closed-form dynamic equations of planar flexible link manipulators (FLMs), with revolute joints and constant cross sections, are derived combining Lagrange’s equations and the assumed mode shape method. To overcome the lengthy and complicated derivative calculation of the Lagrangian function of a FLM, these computations are done only once for a single flexible link manipulator with a moving base (SFLMB). Employing the Lagrange multipliers and the dynamic equations of the SFLMB, the equations of motion of the FLM are derived in terms of the dependent generalized coordinates. To obtain the closed-form dynamic equations of the FLM in terms of the independent generalized coordinates, the natural orthogonal complement of the Jacobian constraint matrix, which is associated with the velocity constraints in the linear homogeneous form, is used. To verify the proposed closed-form dynamic model, the simulation results obtained from the model were compared with the results of the full nonlinear finite element analysis. These comparisons showed sound agreement. One of the main advantages of this approach is that the derived dynamic model can be used for the model based end-effector control and the vibration suppression of planar FLMs.
Vibration Suppression of Rotating Machinery Utilizing Discontinuous Spring Characteristics (Stationary and Nonstationary Vibrations)
Authors: Ishida Yukio , Liu Jun
Published: May 2008

In rotating machinery, resonance phenomena occur with large amplitude in the vicinities of the major critical speeds. In this paper, a new vibration suppression method utilizing a discontinuous spring characteristic is proposed. This spring characteristic is achieved using additional springs with preload. This method has the following advantages. (1) In designing these additional springs, we need not adjust their parameter values to the optimal ones, which are determined by rotor stiffness and the system damping. (2) The amplitude of vibration can be suppressed to any desired small level. (3) This method is also effective for nonstationary vibration. Although the method has a disadvantage that an almost periodic motion occurs above the major critical speed, two countermeasures are proposed to diminish it. The characteristics of the vibration suppression are demonstrated theoretically and experimentally.
Nonlinear Stress Modeling Scheme to Analyze Semiconductor Packages Subjected to Combined Thermal and Hygroscopic Loading
Authors: Yoon Samson , Jang Changsoo , Han Bongtae
Published: May 2008

A nonlinear finite element modeling (FEM) scheme to analyze the combined effect of thermal and hygroscopic deformation is presented. The scheme employs the conventional moisture diffusion, heat transfer, and stress analysis routines available in the commercial FEM package, but offers a unique way of linking the routines to conduct a nonlinear stress analysis of semiconductor packages subjected to moisture as well as temperature excursions. Strategies to implement the proposed scheme using commercial finite element analysis softwares are discussed. The numerical accuracy of the scheme is confirmed with the analytical solution of elastic/viscoelastic composite cylinder subjected to the combined loading of thermal expansion and hygroscopic swelling.
Phonon Transport in Anisotropic Scattering Particulate Media
Authors: Prasher Ravi S.
Published: May 2008

Equation of phonon radiative transport (EPRT) is rewritten to include anisotropic scattering by a particulate media by including an acoustic phase function and an in-scattering term which makes EPRT exactly same as equation of radiative transport (ERT). This formulation of EPRT is called generalized EPRT (GEPRT). It is shown that GEPRT reduces to EPRT for isotropic scattering and is totally consistent with phonon transport theory, showing that transport cross section is different from the scattering cross section. GEPRT leads to same formulation for transport cross section as given by phonon transport theory. However GEPRT shows that transport cross section formulations as described by phonon transport theory are only valid for acoustically thick medium. Transport cross section is different for the acoustically thin medium leading to the conclusion that mean free path (m.f.p) is size dependant. Finally calculations are performed for two types of scatterers for acoustic waves without mode conversion: 1) Acoustically hard Rayleigh sphere 2) large sphere in the geometrical scattering regime. Results show that the scattering from these particles is highly anisotropic. It is also shown that for geometrical scattering case isotropic scattering leads to the conclusion of total internal reflection at the particle/medium interface.
Computational Modeling of Turbulent Flows Over Rough Surfaces
Authors: Chochua Gocha , Shyy Wei
Published: May 2008

Turbulent flows over rough surfaces are often encountered in nature and engineering practices and are often difficult to analyze. In this study, combined modeling and computational techniques is involved to investigate such flows over a surface covered with a large-scale roughness pattern. A simplified empirical engineering model is validated by taking area average of the flow field data over the surface. The approach can interpret fluid physics based on the empirical correlation. The area-averaged mean momentum transport resulting from the wall-normal time-averaged velocity component is found to be a significant contributing term into the near-boundary shear stress balance. This makes its behavior different from the flow over a smooth surface. Comparing alternative approaches for estimating the roughness coefficients, it is found that the mass-flow-rate-deficit approach produces superior results. Flow in a channel with one wall covered with an array of cylindrical cavities and the other smooth is used as an example. The extended wall functions, based on the k-ε closure and the simplified engineering model, can be applied for a large-scale roughness pattern. The approach can significantly reduce required computational cost. On the other hand, the small domain periodic computations are needed to produce roughness lengths for a particular surface geometry. This model can develop a general correlation relating the roughness lengths to a surface geometry to aid engineering design.
The Effect of Thermal Barrier Coating Roughness Magnitude on Heat Transfer With and Without Flowpath Surface Steps
Authors: Bunker Ronald S.
Published: May 2008

An experimental study has been performed to investigate the convective heat transfer coefficients resulting from differing magnitudes of surface roughness for ceramic thermal barrier coatings (TBC) of the type used to protect gas turbine hot section components. A flat plate wind tunnel test is employed with zero freestream pressure gradient, and levels of freestream turbulence from 4.5 to 6.5%. The TBC applied in these tests is an air plasma sprayed, yttriastabalized zirconia-oxide. Average test surface Reynolds numbers are varied from 400,000 to 2,200,000. Average roughness values (RA) for the TBC surfaces are varied by degrees of polishing from 10 μm to 1 μm, resulting in roughness Reynolds numbers of up to 70. Baseline comparison tests use smooth metal surfaces. The changing physical and heat transfer character of the TBC surfaces with polishing is demonstrated. Results show a significant effect of polishing degree on the surface heat transfer coefficients. Such surfaces were also tested with varying magnitudes of forward facing flowpath steps to model the potential interruptions seen at component interfaces. Flowpath steps are shown to produce quite elevated levels of heat transfer for the smooth surfaces, with little or no further additional enhancement due to increased TBC roughness levels.
Methodologies for Damage Identification in MEMS Structures
Authors: Park Kee , Pochiraju Kishore
Published: May 2008

While significant research is focused on the design and fabrication of the MEMS devices, studies on in-service failure evolution and the consequences of failure/damage are limited. Long term embedding and reliable performance of MEMS devices in systems require understanding of failure evolution and recalibration/retuning of the devices. The objective of this research is to study the effects of micro-mechanical damage on MEMS device response and develop techniques for monitoring device failure. This work entails the development and validation of models for simulating device performance and emulating the response of damaged devices. A device level to system level hierarchical methodology is developed to simulate the electro-mechanical operation of MEMS devices. The methodology is illustrated using MEMS-based accelerometer as an example. The response of undamaged devices and devices with a damaged mechanical stage can be simulated using this method. The emulation of a damaged device is carried out using a special finite element developed to represent cracks in the mechanical stage of the MEMS device. An inverse damage detection methodology is formulated using the emulated device response, a local optimization technique and the response from a physical device which enables detection and localization of damage. The damage detection method can establish, while in operation, the extent and the location of damage in the MEMS device. Experimentation with a commercial MEMS accelerometer is performed to measure the characteristics of a physical device and the effectiveness of the damage detection method. Some correlations with experiments are presented. The impact of this research is on improved device reliability and robustness as well as self-calibration features of MEMS devices.
Cryoheater as a Means of Cryosurgery Control
Authors: Rabin Yoed , Stahovich Thomas F.
Published: May 2008

A new concept for cryosurgery control is presented in this report, a concept which has the potential to dramatically change the outcome of cryosurgery. Unlike other cryosurgery control techniques, which are based on controlling the thermal performance of the cryoprobe, this new concept is based on heating the treated tissue as a means of shaping the frozen region. The new controlling heater, which is termed a ‘cryoheater,’ is complimentary to the cryoprobe and can work with any cryosurgery cooling technique. In the current pilot study, the new cryoheater is studied in simulated cases of prostate cryosurgery.
Electroplated Si3N4 Reinforced Metal Matrix Nanocomposites
Authors: Li Xiaochun , Li Zhiwei
Published: May 2008

Permalloy NiFe matrix nanocomposite layers were electroplated on a copper substrate. The volume fraction of nano-sized Si3N4 particles in NiFe matrix was controlled by the addition of various percentages of Si3N4 particles in the NiFe electrolyte. The nanocomposite layers were analyzed by a scanning electron microscopy (SEM). Microhardness test was performed. With nano-sized Si3N4 particles in the NiFe matrix, the microhardness of NiFe was improved. The samples were then annealed at 800 °C for about 20 hours. The microhardness declined more with more Si3N4 particles in the NiFe matrix. The analysis result from Energy Dispersive Spectrometer (EDS) in the SEM showed that the hardness declination could be caused by the segregation of Si3N4 in the NiFe matrix. Finally this paper presents nanocomposite micromolds fabricated by electroplating onto polymer molds that were fabricated by micro-stereolithgraphy.
Application of Laser Scattering on Detection of Subsurface Damage in Silicon Wafers
Authors: Zhang J. M. , Sun J. G. , Pei Z. J.
Published: May 2008

Silicon is widely used in semiconductor industry. Over 90% of all semiconductor devices are manufactured upon silicon substrates (wafers). Many manufacturing processes are needed for the wafer preparation. In order to ensure high quality silicon wafers, the damaged layer induced by each manufacturing process must be reduced or eliminated by its subsequent processes. So, it is critical to assess subsurface damage (SSD). As a nondestructive measurement method, laser scattering is preliminarily applied to measure SSD in silicon wafers. Optical transmission properties of silicon wafer are measured first to make sure that silicon wafers have the appropriate optical transmission properties for laser scattering. Photomicrographs and scatter images are obtained on sample wafers with different depth of subsurface damage. The correlation between photomicrographs and scatter images is discussed. The results from this study show that laser scattering can potentially be applied to measure subsurface damage across whole silicon wafers.
Design and Analysis of Micromachined Thermosyphon for Cooling of High-Power InP HBT Circuits
Authors: Khalkhali H. , Mohammadi S. , Katehi L. P. B. , Kurabayashi K.
Published: May 2008

Integrated InP heterojunction bipolar transistors (HBTs) are used as a high-speed switch in high-power radio frequency (RF) circuits for microwave wireless communications. The power dissipation of each of these devices often reaches as high as 1 W, raising concerns for their thermal reliability. The relatively poor thermal conductivity of InP prohibits effective spreading of heat within the device substrate. To address this problem, this work proposes a novel microfluidic device called the “micro thermosyphon” for cooling the InP-based microwave circuits. This paper describes the concept of the micro thermosyphon and presents its design and analysis, accounting for the large surface tension effect of the working fluid at the micrometer scale. Our simulation suggests that the proposed device could remove a heat flux density as large as 25 W/cm2 from a high-power InP HBT circuit while maintaining the circuit temperature lower than 100 °C. The micro thermosyphon is a fully passive cooling device suited for achieving effective on-chip cooling without requiring any drive power. Experimental work is currently being under way to validate the device performance.
The Dynamic Characteristics of MEMS Driven by Laser Beam
Authors: Arai Yasuhiko , Yokozeki Shunsuke , Aoyagi Seiji , Mori Atsunobu
Published: May 2008

When we drive a micro machine actually, it is very important to supply energy to the micro machine smoothly. The technology that can supply the energy to micro machines by optical beam is discussed. It has been confirmed that the micro cantilever was deformed by the laser beam that was used for the measurement in previous paper. In this paper, this problem is used positively as the new technology that can supply the energy to microstructures. In the experiment, the micro cantilever is driven by the beam of a semiconductor laser that is modulated by a sinusoidal electronic signal. The frequency response of the micro cantilever that is driven by the laser beam is detected. It is confirmed that the resonance curve of the micro cantilever in vacuum shows clearly the property of the mechanical vibration. Such problems and mechanical characteristics of microstructures that are driven by the laser beam are discussed.
Tester to Measure the Tensile Properties of Embryonic Epithelia
Authors: Wiebe Colin , Brodland G. Wayne
Published: May 2008

Described here is a novel tissue tester that can measure the tensile properties of monolayer embryonic epithelia specimens as small as 0.5mm by 0.3mm, something that had not been possible previously. The instrument is used to determine the uniaxial stress-strain characteristics of epithelium from early-stage embryos of the axolotl (Ambystoma mexicanum), a type of amphibian.
Layout Based Full Chip Thermal Simulations of Stacked 3D Integrated Circuits
Authors: Raman Ashok , Turowski Marek , Mar Monte
Published: May 2008

This paper presents full-chip scale detailed thermal simulations of three-dimensional (3D) integrated circuit (IC) stacks. The inter-layer dielectric (ILD) and inter-metal dielectric (IMD) materials inside 3D IC stacks may cause extensive localized heating. The influence of multiple layers of dielectrics on heat trapping inside the 3D stack is analyzed. Different methods to minimize such localized heating are studied. It is shown that the use of thermal vias is very effective in heat dissipation from the hot spots. Comparisons are made between several 3D IC configurations to verify these conclusions.
Metal Injection Molding of Multi-Functional Materials
Authors: Johnson John L. , Tan Lye King , Suri Pavan , German Randall M.
Published: May 2008

Metal injection molding (MIM) enables processing of multi-functional components with combinations of properties including, magnetic and non-magnetic; magnetic response and corrosion resistance; controlled porosity and high thermal conductivity; high inertial weight and high strength; high thermal conductivity and low thermal expansion coefficient; wear resistance and high toughness; high thermal conductivity and good glass-to-metal sealing; high elastic modulus and high damping capacity; and magnetic response and electrical resistance. Such materials can be processed by MIM by co-injection molding and co-sintering, but compositions and sintering cycles must be optimized to minimize stresses arising from shrinkage mismatch while providing the desired properties To determine compatible combinations, individual materials, including various stainless steels and tool steels are mixed with a thermoplastic binder and injection molded. Debound components are subjected to dilatometry to determine dimensional change during sintering. The compatibility of these materials is predicted based on calculations of the thermal stress during co-sintering of concentric rings. For this geometry, shrinkage mismatches result in both radial stresses, which are the highest at the interface and lead to interfacial separation, as well as hoop stresses, which lead to radial cracking. These stresses are dependent on the thicknesses of the inner and outer rings. Defect-free components can be produced when the tensile hoop stresses do not exceed the intrinsic strengths of the component materials. Based on the dilatometry results, low stresses are predicted between a combination of magnetic and non-magnetic stainless steel and between a combination of austenitic stainless steel and tool steel. Example MIM bi-material components are processed from these combinations. The magnetic properties of the tough/wear-resistant bi-material are measured. General predictions and processing guidelines for other multi-functional materials are given.
Calibration of Piezoresistive Cantilever Force Sensors Using the NIST Electrostatic Force Balance
Authors: Pratt Jon R. , Newell David B. , Kramar John A. , Whitenton Eric
Published: May 2008

The characterization of material properties and mechanical performance of micro-electromechanical devices often hinges on the accurate measurement of small forces. Calibrated load cells of appropriate size and range are used, but are often not calibrated in a fashion traceable to the International System of Units (SI). Recently, we calibrated a piezoresistive cantilever in terms of SI force sensitivity. Here, we employ this device as a secondary force standard to calibrate another, optical lever based sensor in a force probe instrument, demonstrating an unbroken tracability chain to appropriate national standards.
A Review of Recent Developments in Atomic Force Microscopy Systems With Application to Manufacturing and Biological Processes
Authors: Laxminarayana Karthik , Jalili Nader
Published: May 2008

The atomic force microscope (AFM) system has evolved into a useful tool for direct measurements of microstructural parameters and intermolecular forces at nanoscale level with atomic-resolution characterization. Typically, these microcantilever systems are operated in three open-loop modes; non-contact mode, contact mode, and tapping mode. In order to probe electric, magnetic, and/or atomic forces of a selected sample, the non-contact mode is utilized by moving the cantilever slightly away from the sample surface and oscillating the cantilever at or near its natural resonance frequency. Alternatively, the contact mode acquires sample attributes by monitoring interaction forces while the cantilever tip remains in contact with the target sample. The tapping mode of operation combines qualities of both the contact and non-contact modes by gleaning sample data and oscillating the cantilever tip at or near its natural resonance frequency while allowing the cantilever tip to impact the target sample for a minimal amount of time. Recent research on AFM systems has focused on many fabrication and manufacturing processes at molecular levels due to its tremendous surface microscopic capabilities. This paper provides a review of such recent developments in AFM imaging systems with emphasis on operational modes, microcantilever dynamic modeling and control. Due to the important contributions of AFM systems to manufacturing, this paper also provides a comprehensive review of recent applications of different AFM systems in these important areas.
Modular Distributed Models of Engineering Structures
Authors: Radcliffe Clark J. , Sticklen Jon
Published: May 2008

Approaches to engineering design and manufacturing such as integrated design and manufacture and just in time fabrication depend on interaction with and among component supply companies that most often use very diverse technologies. The Internet Engineering Design Agents (i-EDA) software system uses a distributed, component-based, agent methodology that is realized following a strong black box approach to modeling. An individual Design Agent (DA) is a virtual product capable of encapsulating both descriptive and model based information about the product it represents. Hierarchically recursive agents for sub-systems and/or components are linked via a communications network to form larger integrated model systems. A two dimensional bridge system structural model is used as an example to illustrate the distributed assembly of structural models from components registered as DA’s on a communications network. Modular Distributed Modeling (MDM) of engineering structures performs static deflection analysis using traditional, fixed causality, structural stiffness models. This paper presents the methodology required to assemble traditional structural stiffness models provided by internet agents representing structural components. The methodology discussed assembles these component models into the structural stiffness model of an assembly distributed by an agents represent that physical assembly of components. Using this modular distributed modeling method; models of complex assemblies can be built and distributed while hiding the topology and characteristics of their structural subassemblies. The automated, modular, assembly of structural stiffness models will be derived for discrete physical connections. Discrete connections are important to the assembly of components such as truss and shaft structures where the relationship between component displacements involve discrete, matching, degrees of freedom on components to be assembled. Specific examples of discrete assembly of truss bridge component models will be presented.
Substrate Centering Method for Robotized Semiconductor Manufacturing Systems
Authors: Hosek Martin , Prochazka Jan
Published: May 2008

This paper describes a method for on-the-fly determination of eccentricity of a circular silicon substrate carried by a robotic manipulator in semiconductor manufacturing applications, where eccentricity refers to the difference between the actual location of the center of the substrate and its desired position on the end-effector of the robotic manipulator. The method utilizes a pair of external optical sensors located along the substrate transfer path. When moving a substrate along the transfer path, the robotic manipulator captures the positions and velocities of the end-effector at which the edges of the substrate are detected by the sensors. These data along with the expected radius of the substrate and the coordinates of the sensors are used to determine the eccentricity of the substrate. This information can be used by the robotic manipulator to compensate for eccentricity of the substrate when performing a place operation, resulting in the substrate being placed centered regardless of the amount and direction of the initial eccentricity. The method can also be employed to detect a defect, such as breakage, of a substrate and report an error condition which can abort or otherwise adjust operation of the robotic manipulator.
Partial-Size Die Forming for Semi-Ellipsoidal Segment Head Parts Using Anticlastic Behavior in Plate Bending
Authors: Kwon Il Keun , Lee Won Jae , Youn Joong Geun
Published: May 2008

A cost-effective forming method for semi-ellipsoidal segment head parts was developed, using the partial-size (P.S.) dies whose width is less than half of the workpiece in the latitudinal direction. The forming method consists of two steps, namely, preliminary forming and final forming. In preliminary forming, the initial flat plate is formed into the semi-product of a spherical shape with the miniature dies. The radius of curvature of the semi-product has an intermediate value of the longitudinal and latitudinal radius of curvature at the center of the final product. In final forming, the preliminarily formed semi-product is bent only in the longitudinal direction with the P.S dies, through which the longitudinal radius of curvature decreases into that of the final product. At the same time, the radius of curvature in the latitudinal direction increases automatically by unbending action due to anticlastic behavior. The radius of curvature of the semi-product was determined from the equation proposed on the basis of the anticlastic behavior and linearity assumption of the material deformation in plate bending. In order to verify the deformation behavior of the semi-product during final forming, F.E analysis was performed using PAMSTAMP and ABAQUS. Prediction of springback after final forming was also done with F.E analysis for a proper design of the P.S dies. Forming tests were performed with the actual semi-ellipsoidal segment head parts. Deformation behavior and springback in final forming of the forming tests were in good agreement with the predictions of F.E analysis and the proposed equation.
Time-Optimum Trajectories for Robots With Multiple End-Effectors
Authors: Hosek Martin
Published: May 2008

Aggressive throughput performance of automated tools for semiconductor and flat-panel-display manufacturing applications have led to development of substrate-handling robots with multiple end-effectors. For maximum throughput levels, a method for calculating a time-optimum substrate transfer trajectory without causing any of the substrates carried by the robot to slide, and without violating other prescribed constraints, is required. This paper presents an algorithm which provides the required functionality with desirable computational efficiency and reliability. The key idea is to identify the set of fundamental trajectory shapes which cover all possible combinations of constraints for a given category of moves, e.g., moves along a straight line or along a circular arc, decompose the fundamental shapes into segments where a single constraint is active, and determine the time-optimum motion profiles in the segments. The fundamental shapes for each of the categories are found as simplified versions of the generic shape which corresponds to the case when all of the constraints are active. Each of the shapes has a set of conditions associated with it to determine whether the shape can be used for a particular move. An example comparison of a motion profile generated based on pre-defined time-optimum shapes with a conventional s-curve trajectory demonstrates that the present algorithm produces substantially faster motion, resulting in an improved throughput performance of the robot.
Integrating SOI and Poly-Si Surface Structures Using a Monolithic Process
Authors: Wu Mingching , Shy Shiunafang , Fang Weileun
Published: May 2008

This work has successfully integrated thick SCS and thin film poly-Si microstructures on a SOI wafer using monolithic processes. Thus high optical quality SOI micromirror and large output microactuators are available using the thick SOI wafer. Moreover, the poly-Si thin film microstructures serve as microhinges and stress-induced self-assembly mechanisms. The microstructures will be lifted and assembled by SixNy/Poly-Si bimorph beams after releasing. This work adopted in-plane movable optical stage and out-of-plane pop-up mirror to demonstrate the characteristic of proposed process. Some reliability testing results showed that the SixNy/Poly-Si bimorph beam was reliable for self-assembly applications. In summary, this integrated process can substantially increase the feasibility and extensibility of fabricating MEMS devices using single crystal silicon (SCS) and poly-Si. In applications, various 3-dimesional optical devices, such as optical switches, variable optical attenuators, and micro-scanners, can be developed by proposed process after assembling the SCS micromirror and poly-Si microstructures.