bluuebunny/crossref_metadata_2025 huggingface dataset:
Solid-State Refrigeration Based on the Electrocaloric Effect for Electronics Cooling
Authors: Ju Y. Sungtaek
Published: November 2010

Subambient temperature operations of advanced semiconductor devices offer many benefits, including improved reliability, reduced leakage currents, and enhanced signal to noise ratios. We discuss a new design concept for compact solid-state refrigerators based on the electrocaloric (EC) effect. The EC refrigerators are attractive because they may approach the Carnot efficiency more closely than Peltier coolers, which involve intrinsically irreversible processes. To address parasitic losses and other practical considerations that limit the actual performance of EC coolers, we incorporate laterally interdigitated electrode arrays with high effective thermal conductivity and switchable thermal interfaces with high switching ratios and high off-state thermal resistance. Numerical simulations are used to quantify the impact of various design parameters and the expected performance of the module, focusing in particular on the heat diffusion time and RC thermal time constant. Based on the material properties reported in the literature, we project that cooling power densities >10 W/cm2 may be achieved across ΔT of the order of 10 K at coefficient of performance (COP)>10. The present work motivates further experimental studies to develop advanced electrocaloric materials and fabricate/test cooling modules to assess the feasibility of their practical application.
Time-Independent and Time-Dependent Inelastic Strain Analysis of Lead-Free Solder by Cyclic Loading Test Using Stepped Ramp Waves
Authors: Ohguchi Ken-ichi , Sasaki Katsuhiko
Published: November 2010

We previously proposed an elastic-plastic-creep model to estimate the fatigue strength of lead-free solder joints subjected to cyclic thermal loading. The proposed model requires detailed experimental data regarding the time-independent plastic strain and the time-dependent creep strain during cyclic thermal loading. This paper proposes an experimental method for determining the characteristics of both the plastic and creep strains generated during cyclic loading that employs stepped ramp waves. This method is applied to cyclic tension-compression loadings using a Sn–3.0Ag–0.5Cu lead-free solder for several loading conditions. The method can separate between the time-independent plastic strain and the time-dependent creep strain in cyclic inelastic deformation of solder alloys.
Apparatus Named After Our Academic Ancestors — I
Authors: Greenslade Thomas B.
Published: November 2010

Let us now praise famous physicists, and the apparatus named after them, with apologies to the writer of Ecclesiastes. I once compiled a list of about 300 pieces of apparatus known to us as X's Apparatus. Some of the values of X are familiar, like Wheatstone and Kelvin and Faraday, but have you heard of Pickering or Rhumkorff or Barlow? In an earlier article about Packard's apparatus,1 I paid homage to an early-20th-century high school teacher, and other articles have mentioned apparatus by a number of other physicists and physics teachers.2 In many cases the apparatus came directly out of research being done by the physicist, or from the need to show the phenomena of physics in the classroom and lecture hall. Here are more stories about apparatus and their makers, starting with three pieces of apparatus that are related to the development of electron physics in the latter half of the 19th century.
Using the Scroll Wheel on a Wireless Mouse as a Motion Sensor
Authors: Taylor Richard S. , Wilson William R.
Published: November 2010

Since its inception in the mid-80s, the computer mouse has undergone several design changes. As the mouse has evolved, physicists have found new ways to utilize it as a motion sensor. For example, the rollers in a mechanical mouse have been used as pulleys to study the motion of a magnet moving through a copper tube as a quantitative demonstration of Lenz's law and to study mechanical oscillators (e.g., mass-spring system and compound pendulum).1–3 Additionally, the optical system in an optical mouse has been used to study a mechanical oscillator (e.g., mass-spring system).4 The argument for using a mouse as a motion sensor has been and continues to be availability and cost. This paper continues this tradition by detailing the use of the scroll wheel on a wireless mouse as a motion sensor.
HLA Class I Molecules Partner with Integrin β
4
to Stimulate Endothelial Cell Proliferation and Migration
Authors: Zhang Xiaohai , Rozengurt Enrique , Reed Elaine F.
Published: November 2010

Interactions between human leukocyte antigen I and the integrin β
4
subunit may contribute to transplant rejection.
The Jasmonate Receptor Is Complex
Authors: Adler Elizabeth M.
Published: November 2010

COI1, JAZ, and inositol pentakisphosphate act as a three-molecule jasmonate co-receptor complex.
Regulating Migration
Authors: Vinson Valda
Published: November 2010

Five crystal structures provide insight into chemokine and HIV-1 recognition.
Germinal Center Survival
Authors: Mueller Kristen L.
Published: November 2010

A protein that inhibits apoptosis is essential for the survival of immune memory cells.
In Silico
Children and the Glass Mouse Model: Clinical Trial Simulations To Identify and Individualize Optimal Isoniazid Doses in Children with Tuberculosis
Authors: Jeena Prakash M. , Bishai William R. , Pasipanodya Jotam G. , Gumbo Tawanda
Published: November 2010

Children with tuberculosis present with high rates of disseminated disease and tuberculous (TB) meningitis due to poor cell-mediated immunity. Recommended isoniazid doses vary from 5 mg/kg/day to 15 mg/kg/day. Antimicrobial pharmacokinetic/pharmacodynamic studies have demonstrated that the ratio of the 0- to 24-h area under the concentration-time curve (AUC
0-24
) to the MIC best explains isoniazid microbial kill. The AUC
0-24
/MIC ratio associated with 80% of maximal kill (80% effective concentration [EC
80
]), considered the optimal effect, is 287.2. Given the pharmacokinetics of isoniazid encountered in children 10 years old or younger, with infants as a special group, and given the differences in penetration of isoniazid into phagocytic cells, epithelial lining fluid, and subarachnoid space during TB meningitis, we performed 10,000 patient Monte Carlo simulations to determine how well isoniazid doses of between 2.5 and 40 mg/kg/day would achieve or exceed the EC
80
. None of the doses examined achieved the EC
80
in ≥90% of children. Doses of 5 mg/kg were universally inferior; doses of 10 to 15 mg/kg/day were adequate only under the very limited circumstances of children who were slow acetylators and had disease limited to pneumonia. Each of the three disease syndromes, acetylation phenotype, and being an infant required different doses to achieve adequate AUC
0-24
/MIC exposures in an acceptable proportion of children. We conclude that current recommended doses for children are likely suboptimal and that isoniazid doses in children are best individualized based on disease process, age, and acetylation status.
Molecular Analysis of Antimicrobial Resistance Mechanisms inNeisseria gonorrhoeaeIsolates from Ontario, Canada
Authors: Allen Vanessa G. , Farrell David J. , Rebbapragada Anuradha , Tan Jingyuan , Tijet Nathalie , Perusini Stephen J. , Towns Lynn , Lo Stephen , Low Donald E. , Melano Roberto G.
Published: November 2010

Surveillance of gonococcal antimicrobial resistance and the molecular characterization of the mechanisms underlying these resistance phenotypes are essential in order to establish correct empirical therapies, as well as to describe the emergence of new mechanisms in local bacterial populations. To address these goals, 149 isolates were collected over a 1-month period (October-November 2008) at the Ontario Public Health Laboratory, Toronto, Canada, and susceptibility profiles (8 antibiotics) were examined. Mutations in previously identified targets or the presence of some enzymes related to resistance (r), nonsusceptibility (ns) (resistant plus intermediate categories), or reduced susceptibility (rs) to the antibiotics tested were also studied. A significant proportion of nonsusceptibility to penicillin (PEN) (89.2%), tetracycline (TET) (72.3%), ciprofloxacin (CIP) (29%), and macrolides (erythromycin [ERY] and azithromycin; 22.3%) was found in these strains. Multidrug resistance was observed in 18.8% of the collection. Although all the strains were susceptible to spectinomycin and extended-spectrum cephalosporins (ESC) (ceftriaxone and cefixime), 9.4% of them displayed reduced susceptibility to extended-spectrum cephalosporins. PBP 2 mosaic structures were found in all of these ESCrsisolates. Alterations in themtrRpromoter, MtrR repressor (TETr, PENns, ESCrs, and ERYns), porin PIB (TETrand PENns), and ribosomal protein S10 (TETr) and double mutations ingyrAandparCquinolone resistance-determining regions (QRDRs) (CIPr) were associated with and presumably responsible for the resistance phenotypes observed. This is the first description of ESCrsin Canada. The detection of this phenotype indicates a change in the epidemiology of this resistance and highlights the importance of continued surveillance to preserve the last antimicrobial options available.
Efficacy of Fosfomycin in Experimental Osteomyelitis Due to Methicillin-Resistant
Staphylococcus aureus
Authors: Poeppl W. , Tobudic S. , Lingscheid T. , Plasenzotti R. , Kozakowski N. , Georgopoulos A. , Burgmann H.
Published: November 2010

The activity of fosfomycin was evaluated in an experimental methicillin-resistant
Staphylococcus aureus
(MRSA) osteomyelitis model. Eighteen rats were treated for 4 weeks with 150 mg of fosfomycin/kg of body weight intraperitoneally once daily or with saline placebo. After treatment, animals were euthanized and the infected tibiae were processed for quantitative bacterial culture. Bone cultures were positive for methicillin-resistant
S. aureus
in all 9 (100%) untreated controls and in 2 of 9 (22.2%) fosfomycin-treated rats. Thus, fosfomycin treatment was significantly more efficacious than placebo. No development of resistance was observed after the 4-week treatment period.
Antibacterial Action of Polyphosphate on
Porphyromonas gingivalis
Authors: Moon Ji-Hoi , Park Jae-Hong , Lee Jin-Yong
Published: November 2010

Polyphosphate [poly(P)] has antibacterial activity against various Gram-positive bacteria. In contrast, Gram-negative bacteria are generally resistant to poly(P). Here, we describe the antibacterial characterization of poly(P) against a Gram-negative periodontopathogen,
Porphyromonas gingivalis
. The MICs of pyrophosphate (Na
4
P
2
O
7
) and all poly(P) (Na

n

+ 2
P

n

O
3

n

+ 1
;
n
= 3 to 75) tested for the bacterium by the agar dilution method were 0.24% and 0.06%, respectively. Orthophosphate (Na
2
HPO
4
) failed to inhibit bacterial growth. Poly-P75 was chosen for further study. In liquid medium, 0.03% poly-P75 was bactericidal against
P. gingivalis
irrespective of the growth phase and inoculum size, ranging from 10
5
to10
9
cells/ml. UV-visible spectra of the pigments from
P. gingivalis
grown on blood agar with or without poly-P75 showed that poly-P75 reduced the formation of μ-oxo bisheme by the bacterium. Poly-P75 increased hemin accumulation on the
P. gingivalis
surface and decreased energy-driven uptake of hemin by the bacterium. The expression of the genes encoding hemagglutinins, gingipains, hemin uptake loci, chromosome replication, and energy production was downregulated, while that of the genes related to iron storage and oxidative stress was upregulated by poly-P75. The transmission electron microscope showed morphologically atypical cells with electron-dense granules and condensed nucleoid in the cytoplasm. Collectively, poly(P) is bactericidal against
P. gingivalis
, in which hemin/heme utilization is disturbed and oxidative stress is increased by poly(P).
Interaction of W-Substituted Analogs of Cyclo-RRRWFW with Bacterial Lipopolysaccharides: the Role of the Aromatic Cluster in Antimicrobial Activity
Authors: Bagheri Mojtaba , Keller Sandro , Dathe Margitta
Published: November 2010

The activity of cyclo-RRRWFW (c-WFW) againstEscherichia colihas been shown to be modulated by the aromatic motif and the lipopolysaccharides (LPS) in the bacterial outer membrane. To identify interaction sites and to elucidate the mode of c-WFW action, peptides were synthesized by the replacement of tryptophan (W) with analogs having altered hydrophobicity, dipole and quadrupole moments, hydrogen-bonding ability, amphipathicity, and ring size. The peptide activity againstBacillus subtilisand erythrocytes increased with increasing hydrophobicity, whereas the effect onE. colirevealed a more complex pattern. Although they had no effect on theE. coliinner membrane even at concentrations higher than the MIC, peptides permeabilized the outer membrane according to their antimicrobial activity pattern, suggesting a major role of LPS in peptide transport across the wall. For isothermal titration calorimetry (ITC) studies of peptide-lipid bilayer interaction, we used POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-choline), either alone or in mixtures with 1-palmitoyl-2-oleoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (POPG), to mimic the charge properties of eukaryotic and bacterial membranes, respectively, as well as in mixtures with lipid A, rough LPS, and smooth LPS as models of the outer membrane ofE. coli. Peptide accumulation was determined by both electrostatic and hydrophobic interactions. The susceptibility of the lipid systems followed the order of POPC-smooth LPS >> POPC-rough LPS > POPC-lipid A = POPC-POPG > POPC. Low peptide hydrophobicity and enhanced flexibility reduced binding. The influence of the other properties on the free energy of partitioning was low, but an enhanced hydrogen-bonding ability and dipole moment resulted in remarkable variations in the contribution of enthalpy and entropy. In the presence of rough and smooth LPS, the binding-modulating role of these parameters decreased. The highly differentiated activity pattern againstE. coliwas poorly reflected in peptide binding to LPS-containing membranes. However, stronger partitioning into POPC-smooth LPS than into POPC-rough LPS uncovered a significant role of O-antigen and outer core oligosaccharides in peptide transport and the permeabilization of the outer membrane and the anti-E. coliactivity of the cyclic peptides.
Immunization with a ZmpB-Based Protein Vaccine Could Protect against Pneumococcal Diseases in Mice
Authors: Gong Yi , Xu Wenchun , Cui Yali , Zhang Xuemei , Yao Run , Li Dairong , Wang Hong , He Yujuan , Cao Ju , Yin Yibing
Published: November 2010

Zinc metalloprotease B (ZmpB) is present in all isolated pneumococcal strains and contributes to the pathogenesis of pneumococcal infection. In this study, recombinant ZmpB was cloned and expressed in
Escherichia coli
. The expression of ZmpB by different pneumococcal strains was detectable by Western blotting with antisera raised to recombinant ZmpB. Flow cytometry analysis demonstrated that anti-ZmpB polyclonal antibodies could bind to the cell surface of the pneumococcal strains analyzed. Both recombinant ZmpB protein and anti-ZmpB polyclonal antibodies significantly inhibited the adhesion of
Streptococcus pneumoniae
D39 to A549 cells. In mouse models, mucosal immunization with recombinant ZmpB could significantly reduce pneumococcal lung colonization caused by
S. pneumoniae
serotypes 19F and 14 and significantly increase mice survival times following invasive pneumococcal challenge with different pneumococcal strains, including serotypes 2, 3, 6B, and 14. Furthermore, intraperitoneal immunization with recombinant ZmpB in combination with the recombinant pneumolysin mutant (DeltaA146 Ply) and heat shock protein 40 (DnaJ) could enhance the protection against pneumococcal infection compared to protection provided by single-protein antigens. Passive immunization with hyperimmune antisera against these three antigens also demonstrated that the combination of three hyperimmune antisera could provide better protection than single antisera. Taken together, our results suggest that ZmpB is a good candidate pneumococcal vaccine antigen.
Interferon γ-release assays for detecting latent tuberculosis infection in patients scheduled for anti-TNFα therapy
Authors: Greveson Kay , Murray Charlie , Toumpanakis Christos , Epstein Owen , Hamilton Mark , Lipman Marc
Published: November 2010

Screening for, and treatment of, latent tuberculosis infection (LTBI) before anti- tumour necrosis factor α therapy has been shown to decrease the incidence of active tuberculosis by more than 80% and is recommended before initiation of treatment. In the absence of a ‘gold standard’ test for LTBI, current screening involves taking a clinical history of risk factors, chest radiograph and tuberculin skin test. Alternative cellular immune-based screening tests have been developed to detectMycobacterium tuberculosisinfection. This paper summarises the current position and advances in the use of newer screening strategies for LTBI.
A test for mental capacity to request assisted suicide
Authors: Stewart Cameron , Peisah Carmelle , Draper Brian
Published: November 2010

The mental competence of people requesting aid-in-dying is a key issue for the how the law responds to cases of assisted suicide. A number of cases from around the common law world have highlighted the importance of competence in determining whether assistants should be prosecuted, and what they will be prosecuted for. Nevertheless, the law remains uncertain about how competence should be tested in these cases. This article proposes a test of competence that is based on the existing common law but which is tailored to cases of assisted suicide. The test will help doctors, other health professionals and lawyers determine whether the suicidal person was able to competently request assistance. Such knowledge will help to reduce some of the current uncertainty about criminal liability in cases of assisted suicide.
Rushing, distraction, walking on contaminated floors and risk of slipping in limited-service restaurants: a case–crossover study
Authors: Verma Santosh K , Lombardi David A , Chang Wen Ruey , Courtney Theodore K , Huang Yueng-Hsiang , Brennan Melanye J , Mittleman Murray A , Ware James H , Perry Melissa J
Published: November 2010

Objectives

This nested case–crossover study examined the association between rushing, distraction and walking on a contaminated floor and the rate of slipping, and whether the effects varied according to weekly hours worked, job tenure and use of slip-resistant shoes.

Methods

At baseline, workers from 30 limited-service restaurants in the USA reported average work hours, average weekly duration of exposure to each transient risk factor and job tenure at the current location. Use of slip-resistant shoes was determined. During the following 12 weeks, participants reported weekly their slip experience and exposures to the three transient exposures at the time of slipping. The case–crossover design was used to estimate the rate ratios using the Mantel–Haenszel estimator for person-time data.

Results

Among 396 participants providing baseline information, 210 reported one or more slips with a total of 989 slips. Rate of slipping was 2.9 times higher when rushing as compared to working at a normal pace (95% CI 2.5 to 3.3). Rate of slipping was also significantly increased by distraction (rate ratio (RR) 1.7, 95% CI 1.5 to 2.0) and walking on a contaminated floor (RR 14.6, 95% CI 12.6 to 17.0). Use of slip-resistant shoes decreased the effects of rushing and walking on a contaminated floor. Rate ratios for all three transient factors decreased monotonically as job tenure increased.

Conclusion

The results suggest the importance of these transient risk factors, particularly floor contamination, on rate of slipping in limited-service restaurant workers. Stable characteristics, such as slip-resistant shoes, reduced the effects of transient exposures.
Workplace smoking policies and their association with male employees' smoking behaviours: a cross-sectional survey in one company in China
Authors: Gao JiaNing , Zheng PinPin , Gao JunLing , Chapman Simon , Fu Hua
Published: November 2010

Objectives

The present work sought to evaluate different worksite smoking control policies and their associations with employees' smoking behaviours and attitudes among Chinese male workers.

Methods

This was a cross-sectional survey with a self-administered standardised questionnaire, conducted among seven production workplaces of one multinational company in Shanghai in 2008. In total, 1043 male workers were involved. Current smoking prevalence, daily cigarette consumption, quitting intention and their potential association with workplace smoking control policies (smoke free or restricted smoking) were measured.

Results

Current smoking prevalence in workplaces where smoke-free policies had been imposed for 3 years was 55.5%, about 18% lower than in workplaces that only restricted smoking. Smokers in smoke-free workplaces also smoked 3.4 cigarettes less per day, made more quit attempts, were more confident of successfully quitting and more willing to accept a company sponsored cessation programme. Those patterns declined or were not found among the workplaces where smoking control policies had been imposed for 10 years. Smoker quitting intentions were not associated with workplace smoking policies regardless of the duration of the policies imposed.

Conclusions

A smoke-free workplace policy was found to have a significant association with lower smoking prevalence and daily cigarette consumption, but not with employee quitting intentions. Restrictive smoking policies had no impact on employee smoking behaviours. The impact of workplace smoking control policies may vary over time.
ON THE HERMAN–KLUK SEMICLASSICAL APPROXIMATION
Authors: ROBERT DIDIER
Published: November 2010

For a subquadratic symbol H on ℝd× ℝd= T*(ℝd), the quantum propagator of the time dependent Schrödinger equation [Formula: see text] is a Semiclassical Fourier-Integral Operator when Ĥ = H(x, ℏDx) (ℏ-Weyl quantization of H). Its Schwartz kernel is described by a quadratic phase and an amplitude. At every time t, when ℏ is small, it is "essentially supported" in a neighborhood of the graph of the classical flow generated by H, with a full uniform asymptotic expansion in ℏ for the amplitude.

In this paper, our goal is to revisit this well-known and fundamental result with emphasis on the flexibility for the choice of a quadratic complex phase function and on global L2estimates when ℏ is small and time t is large. One of the simplest choice of the phase is known in chemical physics as Herman–Kluk formula. Moreover, we prove that the semiclassical expansion for the propagator is valid for [Formula: see text] where δ > 0 is a stability parameter for the classical system.
PAULI–FIERZ MODEL WITH KATO-CLASS POTENTIALS AND EXPONENTIAL DECAYS
Authors: HIDAKA TAKERU , HIROSHIMA FUMIO
Published: November 2010

Generalized Pauli–Fierz Hamiltonian with Kato-class potential K PF in nonrelativistic quantum electrodynamics is defined and studied by a path measure. K PF is defined as the self-adjoint generator of a strongly continuous one-parameter symmetric semigroup and it is shown that its bound states spatially exponentially decay pointwise and the ground state is unique.
EIGENFUNCTION EXPANSIONS AND SPACETIME ESTIMATES FOR GENERATORS IN DIVERGENCE-FORM
Authors: BEN-ARTZI MATANIA
Published: November 2010

Let [Formula: see text] be a formally self-adjoint (elliptic) operator in L2 (ℝn), n ≥ 2. The real coefficients aj, k(x) = ak, j(x) are assumed to be bounded and to coincide with -Δ outside of a ball. The paper deals with two topics: (i) An eigenfunction expansion theorem, proving in particular that H is unitarily equivalent to -Δ, and (ii) Global spacetime estimates for the associated inhomogeneous wave equation, proved under suitable ("nontrapping") additional assumptions on the coefficients. The main tool used here is a Limiting Absorption Principle (LAP) in the framework of weighted Sobolev spaces, which holds also at the threshold.
A NOTE ON AN EXTENDED NUMERATION METHOD FOR SOLVING FREE DISPOSAL HULL MODELS IN DEA
Authors: ALIREZAEE MOHAMMAD REZA , SHIRAZ RASHED KHANJANI
Published: November 2010

This note identifies and corrects an error in Keshvari, A and N Dehghan Hardoroudi (2008). Asia-Pacific Journal of Operational Research, 25, 689–696.
TWO-STAGE FLOWSHOP SCHEDULING PROBLEMS WITH IDENTICAL AND BATCH PROCESSORS
Authors: WANG WEN-WEI , HE LONG-MIN , CHENG MING-BAO
Published: November 2010

This paper considers minimizing total completion time in a two-stage flowshop scheduling problem with m identical parallel machines at Stage 1 and a batch processor at Stage 2. We prove that the problem when all jobs have same processing time at Stage 2 is NP – hard and gave a two-approximation algorithm in O(n3) time. In the case that all jobs have arbitrary processing time at Stage 1 and at Stage 2, we give an approximation algorithm after pointing out that in this case the problem is strongly NP – hard. Hundreds of instances of a numerical experiment show that the worst-case ratio of this approximation algorithm is nearing 2.
MODULE DESIGN WITH COMMUNICATION AND RECONFIGURATION FOR SNAKE-TYPE MODULAR ROBOTIC SYSTEMS
Authors: LIAN FENG-LI , LIN PING-CHIH
Published: November 2010

In this paper, the module hardware design is addressed and a wireless communication algorithm is proposed for the motion coordination and reconfiguration planning of snake-type robots. The objective of the modular design and the planning algorithm is on self-intelligence and distributed feature for the adding of new modules and the removal of broken parts during motion reconfiguration. Particularly, the automatic connector and wireless communication are implemented on each module, and a planning algorithm for motion reconfiguration is proposed for determining the physical position and acting role of the sequential connected modules in a snake-like robot. Finally, two types of case studies are conducted for testing the communication feasibility and motion reconfigurability of the proposed robotic modules.
CONDITION MONITORING IN A HYDRAULIC SYSTEM OF AN INDUSTRIAL MACHINE USING UNSCENTED KALMAN FILTER
Authors: RAZAVI BEHNAM , DE SILVA CLARENCE W.
Published: November 2010

This paper develops a model-based technique based on the Unscented Kalman Filter (UKF) for on-line condition monitoring, and applies it to the hydraulic system of an automated industrial fish processing machine. First an analytical model of the hydraulic system is developed and the system parameters are identified (determined). Then the developed UKF approach is implemented in the machine. The UKF employs an unscented transformation to select a minimal set of sample points around the mean, which are then propagated through nonlinear functions, from which the mean and covariance of the estimate are recovered. This approach is known to be more accurate for nonlinear systems. For experimental investigation of the performance of the approach, four common hydraulic faults are deliberately introduced into the machine. The four faults are external leakage in the two chambers of the hydraulic cylinder; internal leakage; and dry friction build-up at the moving support plate of the cutter carriage. Three levels of leakage are manually introduced to the system for each fault scenario using needle valves. The criteria that are considered in fault diagnosing are residual moving average of the errors, chamber pressures, and actuator characteristics. The experimental results show that the developed technique is able to accurately determine the fault conditions of the machine.
REAL-TIME MEASUREMENT OF ICE CONCENTRATIONS IN ICE SLURRY FLOW
Authors: PECK JONG HYEON , HONG HIKI , KANG CHAEDONG
Published: November 2010

An experimental study was performed to measure the ice concentration of an ice slurry pipe flow in real time. In the present work, we suggest a refractive index measurement method and compare it to freezing point and density measurement methods. To measure the refractive index of the solution, ice particles in the ice slurry should be completely removed and a hydro-cyclone was used in this study instead of a mesh. The results from the measurement method by the refractive index coincided with those by the density within a ±5% error range when the real-time solution density was used. Even though the density measurement method showed good resolution, the results using the initial density of the solution were more than 10% in error compared to those using the real-time density. And the density measurement method has an error range 1.5 times greater than the refractive index measurement method.
PURE NH3 AND CO2 HEAT TRANSFER AND PRESSURE DROP IN HORIZONTAL SMOOTH TUBES FOR NH3 TWO-STAGE AND NH3/CO2 CASCADE REFRIGERATION SYSTEMS: A REVIEW
Authors: PARK C. Y. , HRNJAK P. S.
Published: November 2010

This paper presents a review of differences and similarities of in-tube heat transfer and pressure drop between ammonia (NH3) and carbon dioxide (CO2) from the perspective of the design of heat exchangers for NH3 two-stage and CO2/NH3 cascade refrigeration systems. The focus is on differences in thermophysical properties and thus different characteristics of heat transfer and pressure drop. A brief summary of published literatures about CO2/NH3 cascade refrigeration systems is provided and literature review of available correlations and developed correlations are presented for flow boiling and condensation heat transfer and pressure drop. Because of large deviation of calculated values with exiting correlations from measured results, a new correlation to predict flow condensation heat transfer coefficients was developed based on experimental results for CO2 at -15°C. From comparison of measured and predicted values, it is shown that some correlations, previously published in open literature, can be used to calculate flow boiling heat transfer coefficients for NH3 at -20°C, if a flow pattern can be appropriately determined for a flow condition. Also, it is presented that existing correlations can predict well the heat transfer coefficients for CO2 flow boiling at -15 and -30°C. It is shown that some correlations can predict pressure drop relatively well for NH3 and CO2 two-phase flow. The NH3 and CO2 flow evaporation heat transfer and pressure drop characteristics at -40°C are compared with predicted values.
A STUDY ON THE FAN EFFICIENCY DECREASE ON THE BACKWARD FLOW IN AN AXIAL FAN WITH ADJUSTABLE PITCH BLADE
Authors: KIM HWA-YOUNG , YOON SUNG-HOON , MOON SEUNG-JAE , LEE JAE-HEON , YOO HOSEON , IM YUN-CHUL
Published: November 2010

In this study, a numerical study has been carried out to analyze the factors of the efficiency decrease at backward flow situation in an axial fan with adjustable blades. The analysis is done with the pitch angle of 36° on the forward flow and of -26° on the backward flow. The numerical results show that the air flow rates of the pitch angle of 36° and -6° are calculated to be 285 cubic meter per min (CMM) and 212 CMM, respectively. The results are similar to the experimental results by Chang et al.1 The results had the maximum error of 10.6% compared with the experimental results. The fan efficiency decrease is caused by the fact that the axial fan used for this study was designed for the forward flow. As the results, the pitch angle of -26° has induced the recirculation around the impeller blade, impeller cover and downstream. This recirculation caused the large decrease in total pressure coefficient. This turned out to be the main cause of the efficiency decrease.
PERFORMANCE CHARACTERISTICS OF A BYPASS TWO-CIRCUIT REFRIGERATION CYCLE DESIGNED FOR REFRIGERATORS
Authors: JUNG HAE WON , YOON WONJAE , CHUNG HYUN JOON , KIM YONGCHAN
Published: November 2010

In this study, the performance characteristics of a bypass two-circuit refrigeration cycle designed for refrigerators were investigated in a bench scale refrigeration system. The bypass two-circuit refrigeration cycle with R600a operates in two modes of refrigerator/freezer-mode (RF-mode) and freezer only-mode (F only-mode) by switching refrigerant flow path. The performance of the bypass two-circuit refrigeration cycle was measured by varying the condenser capacity, the length of the suction line heat exchanger (SLHX), and the refrigerant charge amount with adoption of the refrigerant storage vessel. The COPs of the bypass two-circuit refrigeration cycle at RF-mode and F only-mode increased by 10% and 17%, respectively, with the increase of the condenser capacity and SLHX length. In addition, the COP of the system at F only-mode increased by 10% with the adoption of the refrigerant storage vessel.
Clustering-based incremental web crawling
Authors: Tan Qingzhao , Mitra Prasenjit
Published: November 2010

When crawling resources, for example, number of machines, crawl-time, and so on, are limited, so a crawler has to decide an optimal order in which to crawl and recrawl Web pages. Ideally, crawlers should request only those Web pages that have changed since the last crawl; in practice, a crawler may not know whether a Web page has changed before downloading it. In this article, we identify features of Web pages that are correlated to their change frequency. We design a crawling algorithm that clusters Web pages based on features that correlate to their change frequencies obtained by examining past history. The crawler downloads a sample of Web pages from each cluster, and depending upon whether a significant number of these Web pages have changed in the last crawl cycle, it decides whether to recrawl the entire cluster. To evaluate the performance of our incremental crawler, we develop an evaluation framework that measures which crawling policy results in the best search results for the end-user. We run experiments on a real Web data set of about 300,000 distinct URLs distributed among 210 Web sites. The results demonstrate that the clustering-based sampling algorithm effectively clusters the pages with similar change patterns, and our clustering-based crawling algorithm outperforms existing algorithms in that it can improve the quality of the user experience for those who query the search engine.
School grades need improvement
Authors: Roman David
Published: November 2010

Much has been written over the last decade about the abysmal state of the education arms race in the U.S., particularly in the STEM disciplines. Two recent reports show how little has been done to redirect that trend and what will happen if the spiral does not end.
Topic models vs. unstructured data
Authors: Anthes Gary
Published: November 2010

With topic modeling, scientists can explore and understand huge collections of unlabeled information.
We need a research data census
Authors: Berman Francine
Published: November 2010

The increasing volume of research data highlights the need for reliable, cost-effective data storage and preservation at the national scale.
The theft of business innovation
Authors: Creeger Mache
Published: November 2010

These days, cybercriminals are looking to steal more than just banking information.
Certified software
Authors: Shao Zhong
Published: November 2010

Only if the programmer can prove (through formal machine-checkable proofs) it is free of bugs with respect to a claim of dependability.
Bayesian networks
Authors: Darwiche Adnan
Published: November 2010

What are Bayesian networks and why are their applications growing across all fields?
MultiFusion
Authors: Wang Xiangyu , Kankanhalli Mohan
Published: November 2010

The multimodal data usually contain complementary, correlated and redundant information. Thus, multimodal fusion is useful for many multisensor applications. Here, a novel multimodal fusion algorithm is proposed, which is referred to as “MultiFusion.” The approach adopts a boosting structure where the atomic event is considered as the fusion unit. The correlation of multimodal data is used to form an overall classifier in each iteration. Moreover, by adopting the Adaboost-like structure, the overall fusion performance is improved. Both the simulation experiment and the real application show the effectiveness of the MultiFusion approach. Our approach can be applied in different multimodal applications to exploit the multimedia data characteristics and improve the performance.
Dialocalization
Authors: Friedland Gerald , Yeo Chuohao , Hung Hayley
Published: November 2010

The following article presents a novel audio-visual approach for unsupervised speaker localization in both time and space and systematically analyzes its unique properties. Using recordings from a single, low-resolution room overview camera and a single far-field microphone, a state-of-the-art audio-only speaker diarization system (speaker localization in time) is extended so that both acoustic and visual models are estimated as part of a joint unsupervised optimization problem. The speaker diarization system first automatically determines the speech regions and estimates “who spoke when,” then, in a second step, the visual models are used to infer the location of the speakers in the video. We call this process “dialocalization.” The experiments were performed on real-world meetings using 4.5 hours of the publicly available AMI meeting corpus. The proposed system is able to exploit audio-visual integration to not only improve the accuracy of a state-of-the-art (audio-only) speaker diarization, but also adds visual speaker localization at little incremental engineering and computation costs. The combined algorithm has different properties, such as increased robustness, that cannot be observed in algorithms based on single modalities. The article describes the algorithm, presents benchmarking results, explains its properties, and systematically discusses the contributions of each modality.
Tradeoffs and Average-Case Equilibria in Selfish Routing
Authors: Hoefer Martin , Souza Alexander
Published: November 2010

We study Nash equilibria in a selfish routing game on
m
parallel links with transmission speeds. Each player seeks to communicate a message by choosing one of the links, and each player desires to minimize his experienced transmission time (latency). For evaluating the social cost of Nash equilibria, we consider the price of anarchy, which is the largest ratio of the cost of any Nash equilibrium compared to the optimum solution. Similarly, we consider the price of stability, which is the smallest ratio. The main purpose of this article is to quantify the influence of three parameters upon the prices of the game: the total traffic in the network; restrictions of the players in terms of link choice; and fluctuations in message lengths.

Our main interest is to bound the sum of all player latencies, which we refer to as
collective latency
. For this cost, the prices of anarchy and stability are
Θ
(
n
/
t
), where
n
is the number of players and
t
the sum of message lengths (total traffic); that is, Nash equilibria approximate the optimum solution up to a constant factor if the traffic is high. If each player is restricted to choose from a subset of links, these link restrictions can cause a degradation in performance of order Θ(\sqrt{
m
}). The prices of anarchy and stability increase to Θ(
n
\sqrt{
m
}/
t
).

We capture fluctuations in message lengths through a stochastic model, in which we valuate Nash equilibria in terms of their expected price of anarchy. The expected price is Θ(
n
/\mathbb{E}[
T
]), where \mathbb{E}[
T
] is the expected traffic. The stochastic model resembles the deterministic one, even for the efficiency loss of order Θ(\sqrt{
m
}) for link restrictions.

For the social cost function maximum latency, the (expected) price of anarchy is 1 + 
m
2
/
t
. In this case, Nash equilibria are almost optimal solutions for congested networks. Similar results hold when the cost function is a polynomial of the link loads.
DevLearn 2010 Conference Wrap
Authors: Duffy Jill
Published: November 2010

DevLearn 10, a U.S.-based e-learning conference put on by eLearning Guild, took place November 3-5 in San Francisco. While a multitude of blog posts, web sites, and Twitter messages using the tag #dl10 have given various snapshots of the event, eLearn Magazine brings you this unique review of the coverage: 20 take-away ideas from the sessions, keynote speakers, and thought leaders at the event.
Analogies in science and science teaching
Authors: Brown Simon , Salter Susan
Published: November 2010

Analogies are often used in science, but students may not appreciate their significance, and so the analogies can be misunderstood or discounted. For this reason, educationalists often express concern about the use of analogies in teaching. Given the important place of analogies in the discourse of science, it is necessary that students are explicitly shown how they work, perhaps based on the structure-mapping theory we outline here. When using an analogy, the teacher should very clearly specify both its components and its limitations. Great care is required in developing an analogy to ensure that it is understood as intended and that misconceptions are minimized. This approach models the behavior of a scientist, which helps to develop student understanding of the practice of science.
A comparison between learning style preferences and sex, status, and course performance
Authors: Dobson John L.
Published: November 2010

Students have learning style preferences that are often classified according to their visual (V), aural (A), read-write (R), and/or kinesthetic (K) sensory modality preferences (SMP). The purposes of this investigation were to compare student perceived and assessed SMPs and examine the associations between those SMPs and status (i.e., undergraduates vs. graduates), sex, and course performance. Students from the fall 2009 APK 3110 and APK 6116 Exercise Physiology courses were asked to indicate their perceived SMPs and complete the standard VARK SMP assessment. There were 64 student respondents: 50 undergraduates and 14 graduates (40 women and 24 men). According to the perceived SMP results, the largest number of respondents chose V (36%), followed by R (28%), K (19%), and A (17%). In terms of assessed SMPs, the largest number of respondents were classified as VARK (37%), followed by R (14%), AK (11%), K (8%), VK (6%), ARK (6%), A (5%), VAK (3%), RK (3%), V (2%), AR (2%), and VRK (2%). Nearly two-thirds of the respondents correctly matched their perceived and dominant assessed SMP. There was no statistical association between SMP and status. There was a very nearly significant relationship between sex and both perceived (χ2= 7.18, P = 0.06) and assessed (χ2= 17.36, P = 0.09) SMP. Finally, there was a significant relationship between perceived SMP and course scores ( P = 0.01 by ANOVA). Post hoc tests revealed that the K group scored significantly lower than the other three modality groups.
Are online student evaluations of faculty influenced by the timing of evaluations?
Authors: McNulty John A. , Gruener Gregory , Chandrasekhar Arcot , Espiritu Baltazar , Hoyt Amy , Ensminger David
Published: November 2010

Student evaluations of faculty are important components of the medical curriculum and faculty development. To improve the effectiveness and timeliness of student evaluations of faculty in the physiology course, we investigated whether evaluations submitted during the course differed from those submitted after completion of the course. A secure web-based system was developed to collect student evaluations that included numerical rankings ( 1–5) of faculty performance and a section for comments. The grades that students received in the course were added to the data, which were sorted according to the time of submission of the evaluations and analyzed by Pearson's correlation and Student's t-test. Only 26% of students elected to submit evaluations before completion of the course, and the average faculty ratings of these evaluations were highly correlated [ r( 14 ) = 0.91] with the evaluations submitted after completion of the course. Faculty evaluations were also significantly correlated with the previous year [ r( 14 ) = 0.88]. Concurrent evaluators provided more comments that were statistically longer and subjectively scored as more “substantive.” Students who submitted their evaluations during the course and who included comments had significantly higher final grades in the course. In conclusion, the numeric ratings that faculty received were not influenced by the timing of student evaluations. However, students who submitted early evaluations tended to be more engaged as evidenced by their more substantive comments and their better performance on exams. The consistency of faculty evaluations from year to year and concurrent versus at the end of the course suggest that faculty tend not to make significant adjustments to student evaluations.
Diffusive insights: on the disagreement of Christian Bohr and August Krogh at the Centennial of the Seven Little Devils
Authors: Gjedde Albert
Published: November 2010

The year 2010 is the centennial of the publication of the “Seven Little Devils” in the predecessor of Acta Physiologica. In these seven papers, August and Marie Krogh sought to refute Christian Bohr's theory that oxygen diffusion from the lungs to the circulation is not entirely passive but rather facilitated by a specific cellular activity substitute to secretion. The subjects of the present reevaluation of this controversy are Christian Bohr, Professor and Doctor of Medicine (1855–1911), nominated three times for the Nobel Prize; August Krogh, Doctor of Philosophy (1874–1949), Christian Bohr's assistant and later Nobel Prize laureate (1920); and Marie Krogh, née Jørgensen, Doctor of Medicine and wife of August Krogh (1874–1943). The controversy concerned is the transport of oxygen from the lungs into the bloodstream: are passive transport and diffusion capacity together sufficient to secure the oxygen supply in all circumstances or is there an additional specific (“energy consuming” or “active”) mechanism responsible for the transport of oxygen from the alveoli into the bloodstream? The present discussion purports to show that the contestants' views were closer than the parties themselves and posterity recognized. Posterity has judged the dispute unilaterally from the Nobel laureate's point of view, but it is evident that August Krogh's Nobel Prize was awarded for the discovery of a cellular activity (Christian Bohr's expression), represented by Krogh's discovery of capillary recruitment. Christian Bohr appears to have been correct in the narrower sense that the diffusion capacity at rest is not great enough to explain the transport during work; a special mechanism intervenes and optimizes the conditions under which diffusion acts. August Krogh, of course, was right in the wider sense that the transport mechanism itself is always entirely passive.