bluuebunny/crossref_metadata_2025 huggingface dataset:
High performance solar cell based on ultra-thin poly(3-hexylthiophene): Fullerene film without thermal and solvent annealing
Authors: Wu Zhongwei , Song Tao , Jin Yizheng , Sun Baoquan
Published: October 2011

A method has been developed to fabricate organic solar cell based on poly(3-hexylthiopene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) film with a thickness as thin as ∼60 nm. The P3HT chain ordering can be dramatically enhanced by slow solvent evaporation process, which is verified by obvious vibronic features and enhanced absorption capability. Due to the improvement of P3HT chain ordering degree, the solar cell based on ultrathin film achieves the power conversion efficiency of 3.7%. Furthermore, the fabrication process does not require any post-treatments such as solvent-vapor or thermal annealing process, which is more compatible with future plastic substrates.
The role of excitations statistic and nonlinearity in energy harvesting from random impulsive excitations
Authors: Khovanova N. A. , Khovanov I. A.
Published: October 2011

Design of an efficient energy harvester is now feasible as technology develops and a viable approach to solve this need is to exploit the concept and application of a nonlinear design. In this letter, we conducted a comparative analysis of linear and nonlinear piezoelectric energy harvesting from random impulsive excitations modelled by white Poisson noise. It is shown that the harvester performance depends on both nonlinearity and properties of ambient energy, and nonlinearity should be optimized for a given type of ambient vibration in order to achieve efficient harvesting.
Long hold times in a two-junction electron trap
Authors: Kemppinen A. , Lotkhov S. V. , Saira O.-P. , Zorin A. B. , Pekola J. P. , Manninen A. J.
Published: October 2011

The hold time τ of a single-electron trap is shown to increase significantly due to suppression of photon assisted tunneling events. Using two rf-tight radiation shields instead of a single one, we demonstrate increase of τ by a factor exceeding 103, up to about 10 h, for a trap with only two superconductor (S)—normal-metal (N) tunnel junctions and an on-chip resistor R ∼ 100 kΩ (R-SNS structure). In the normal state, the improved shielding made it possible to observe τ ∼ 100 s, which is in reasonable agreement with the quantum-leakage-limited level expected for the two-electron cotunneling process.
Impaired phosphorylation of Na
+
-K
+
-2Cl
−
cotransporter by oxidative stress-responsive kinase-1 deficiency manifests hypotension and Bartter-like syndrome
Authors: Lin Shih-Hua , Yu I-Shing , Jiang Si-Tse , Lin Shu-Wha , Chu Pauling , Chen Ann , Sytwu Huey-Kang , Sohara Eisei , Uchida Shinichi , Sasaki Sei , Yang Sung-Sen
Published: October 2011

Na
+
-K
+
-2Cl
−
cotransporters (NKCCs), including NKCC1 and renal-specific NKCC2, and the Na
+
-Cl
−
cotransporter (NCC) play pivotal roles in the regulation of blood pressure (BP) and renal NaCl reabsorption. Oxidative stress-responsive kinase-1 (OSR1) is a known upstream regulator of N(K)CCs. We generated and analyzed global and kidney tubule-specific (KSP) OSR1 KO mice to elucidate the physiological role of OSR1 in vivo, particularly on BP and kidney function. Although global OSR1
−/−
mice were embryonically lethal, OSR1
+/−
mice had low BP associated with reduced phosphorylated (p) STE20 (sterile 20)/SPS1-related proline/alanine-rich kinase (SPAK) and p-NKCC1 abundance in aortic tissue and attenuated p-NKCC2 abundance with increased total and p-NCC expression in the kidney. KSP-OSR1
−/−
mice had normal BP and hypercalciuria and maintained significant hypokalemia on a low-K
+
diet. KSP-OSR1
−/−
mice exhibited impaired Na
+
reabsorption in the thick ascending loop on a low-Na
+
diet accompanied by remarkably decreased expression of p-NKCC2 and a blunted response to furosemide, an NKCC2 inhibitor. The expression of total SPAK and p-SPAK was significantly increased in parallel to that of total NCC and p-NCC despite unchanged total NKCC2 expression. These results suggest that, globally, OSR1 is involved in the regulation of BP and renal tubular Na
+
reabsorption mainly via the activation of NKCC1 and NKCC2. In the kidneys, NKCC2 but not NCC is the main target of OSR1 and the reduced p-NKCC2 in KSP-OSR1
−/−
mice may lead to a Bartter-like syndrome.
Effects of Salinity on Physa acuta, the Intermediate Host for the Parasite Posthodiplostomum minimum: Implications for the Translocation of the Protected White Sands Pupfish
Authors: Stockwell Craig A. , Purcell Kevin M. , Collyer Michael L. , Janovy John
Published: October 2011

We report the salinity tolerance of snails to evaluate how parasite communities with complex life cycles have been altered by translocations of the White Sands pupfish Cyprinodon tularosa to habitats with altered salinity levels. Native and introduced pupfish populations co‐occur with the gastropods Physa acuta and associated white grub parasite, Posthodiplostomum minimum, at two brackish springs (Malpais and Mound), but physids are absent from the two saline habitats occupied by White Sands pupfish. We conducted a salinity challenge experiment to test the hypothesis that environmental salinity limits the distribution of physid snails. A 22‐d survival experiment with the Malpais Spring physid population indicated that exposure to elevated salinities significantly reduced survival. We also saw sequential declines in survival and reproduction that were proportional to salinity exposure. Salinity of 7‰ was the apparent threshold for these effects. These results have implications for the use of translocation as a conservation tool in the management of fish populations.
Scared and less noisy: glucocorticoids are associated with alarm call entropy
Authors: Blumstein Daniel T. , Chi Yvonne Y.
Published: October 2011

The nonlinearity and arousal hypothesis predicts that highly aroused mammals will produce nonlinear, noisy vocalizations. We tested this prediction by measuring faecal glucocorticoid metabolites (GCMs) in adult yellow-bellied marmots (
Marmota flaviventris
), and asking if variation in GCMs was positively correlated with Wiener entropy—a measure of noise. Contrary to our prediction, we found a significant negative relationship: marmots with more faecal GCMs produced calls with less noise than those with lower levels of GCMs. A previous study suggested that glucocorticoids modulate the probability that a marmot will emit a call. This study suggests that, like some other species, calls emitted from highly aroused individuals are less noisy. Glucocorticoids thus play an important, yet underappreciated role, in alarm call production.
Convenience polyandry or convenience polygyny? Costly sex under female control in a promiscuous primate
Authors: Huchard Elise , Canale Cindy I. , Le Gros Chloé , Perret Martine , Henry Pierre-Yves , Kappeler Peter M.
Published: October 2011

Classic sex roles depict females as choosy, but polyandry is widespread. Empirical attempts to understand the evolution of polyandry have often focused on its adaptive value to females, whereas ‘convenience polyandry’ might simply decrease the costs of sexual harassment. We tested whether constraint-free female strategies favour promiscuity over mating selectivity through an original experimental design. We investigated variation in mating behaviour in response to a reversible alteration of sexual dimorphism in body mass in the grey mouse lemur, a small primate where female brief sexual receptivity allows quantifying polyandry. We manipulated body condition in captive females, predicting that convenience polyandry would increase when females are weaker than males, thus less likely to resist their solicitations. Our results rather support the alternative hypothesis of ‘adaptive polyandry’: females in better condition are more polyandrous. Furthermore, we reveal that multiple mating incurs significant energetic costs, which are strikingly symmetrical between the sexes. Our study shows that mouse lemur females exert tight control over mating and actively seek multiple mates. The benefits of remating are nevertheless not offset by its costs in low-condition females, suggesting that polyandry is a flexible strategy yielding moderate fitness benefits in this small mammal.
Natural and experimental infection of dogs with pandemic H1N1/2009 influenza virus
Authors: Lin Degui , Sun Shasha , Du Lijie , Ma Jingjiao , Fan Linghong , Pu Juan , Sun Yipeng , Zhao Jingyi , Sun Honglei , Liu Jinhua
Published: October 2011

Evidence of H1N1/2009 influenza virus infection was identified in two domestic dogs in China in November 2009. Virus isolation and sequence analysis of all eight genes of the two isolates showed that they were related closely to the H1N1/2009 influenza virus circulating in humans, indicating that they were probably acquired from humans. To determine the pathogenicity and transmissibility of H1N1/2009 influenza virus in dogs, experimental infection and transmission were performed. Inoculated dogs were able to shed virus in nasal secretions, but symptoms were very mild. Uninoculated dogs were co-mingled to determine the transmissibility of the isolate, and one of three exposed dogs was shown to develop infection. The present findings indicate that human H1N1/2009 can infect dogs, but is transmitted inefficiently between dogs.
Posttranslational Regulation of the Iron Deficiency Basic Helix-Loop-Helix Transcription Factor FIT Is Affected by Iron and Nitric Oxide
Authors: Meiser Johannes , Lingam Sivasenkar , Bauer Petra
Published: October 2011

Understanding iron (Fe) sensing and regulation is important for targeting key genes for important nutritional traits like Fe content. The basic helix-loop-helix transcription factor FIT (for FER-LIKE FE DEFICIENCY-INDUCED TRANSCRIPTION FACTOR) controls Fe acquisition genes in dicot roots. Posttranscriptional regulation of transcription factors allows rapid adaptation to cellular changes and was also described for FIT. However, the mechanisms behind this regulation of FIT were for a long time not known. Here, we studied the posttranscriptional control mechanisms of FIT in Arabidopsis (Arabidopsis thaliana) and identified nitric oxide as a stabilizing stimulus for FIT protein abundance. Using cycloheximide, we confirmed that the level of FIT protein was regulated by way of protein turnover in wild-type and hemagglutinin-FIT plants. Upon cycloheximide treatment, FIT activity was hardly compromised, since Fe deficiency genes like IRON-REGULATED TRANSPORTER1 and FERRIC REDUCTASE OXIDASE2 were still inducible by Fe deficiency. A small pool of “active” FIT was sufficient for the induction of Fe deficiency downstream responses. Nitric oxide inhibitors caused a decrease of FIT protein abundance and, in the wild type, also a decrease in FIT activity. This decrease of FIT protein levels was reversed by the proteasomal inhibitor MG132, suggesting that in the presence of nitric oxide FIT protein was less likely to be a target of proteasomal degradation. Independent of FIT transcription, FIT protein stability and FIT protein activity, therefore, were targets of control mechanisms in response to Fe and nitric oxide. We summarize our results in a model that explains the different steps of FIT regulation integrating the plant signals that control FIT.
Pollinator effectiveness of native and non‐native flower visitors to an apparently generalist Andean shrub,Duranta mandonii(Verbenaceae)
Authors: WATTS STELLA , OVALLE DAVID HUAMÁN , HERRERA MARCELA MORENO , OLLERTON JEFF
Published: October 2011

Not all visitors to flowers are pollinators and pollinating taxa can vary greatly in their effectiveness. Using a combination of observations and experiments we compared the effectiveness of introduced honeybees with that of hummingbirds, native bees and moths on both the male and female components of fitness of the Andean shrubDuranta mandonii(Verbenaceae). Our results demonstrated significant variation among flower visitors in rates of visitation, pollen removal ability and contribution to fruit set. This variation was not always correlated; that is, taxa that regularly visited flowers did not remove the most pollen or contribute to fruit set. Despite the taxonomic diversity of visitors, the main natural pollinators of this shrub are large native bees, such asBombusspp. Introduced honeybees were found to be as effective as native bees at pollinating this species.Duranta mandoniihas high apparent generalization, but low realized generalization and can be considered to be a moderate ecological generalist (a number of species of large bees provide pollination services), but a functional specialist (most pollinators belong to a single functional group). The present study has highlighted the importance of measuring efficiency components when documenting plant–pollinator interactions, and has also demonstrated that visitation rates may give little insight into the relative importance of flower visitors.
Evaluation of speech and language assessment approaches with bilingual children
Authors: De Lamo White Caroline , Jin Lixian
Published: October 2011

Background:British society is multicultural and multilingual, thus for many children English is not their main or only language. Speech and language therapists are required to assess accurately the speech and language skills of bilingual children if they are suspected of having a disorder. Cultural and linguistic diversity means that a more complex assessment procedure is needed and research suggests that bilingual children are at risk of misdiagnosis. Clinicians have identified a lack of suitable assessment instruments for use with this client group.

Aims:This paper highlights the challenges of assessing bilingual children and reviews available speech and language assessment procedures and approaches for use with this client group. It evaluates different approaches for assessing bilingual children to identify approaches that may be more appropriate for carrying out assessments effectively.

Methods & Procedures:This review discusses and evaluates the efficacy of norm‐referenced standardized measures, criterion‐referenced measures, language‐processing measures, dynamic assessment and a sociocultural approach.

Outcomes & Results:When all named procedures and approaches are compared, the sociocultural approach appears to hold the most promise for accurate assessment of bilingual children. Research suggests that language‐processing measures are not effective indicators for identifying speech and language disorders in bilingual children, but further research is warranted. The sociocultural approach encompasses some of the other approaches discussed, including norm‐referenced measures, criterion‐referenced measures and dynamic assessment.

Conclusions & Implications:The sociocultural approach enables the clinician to interpret results in the light of the child's linguistic and cultural background. In addition, combining approaches mitigates the weaknesses inherent in each approach.
Impact of Public and Private Cash Transfers on Poverty and Inequality: Evidence from Vietnam
Authors: Van den Berg Marrit , Cuong Nguyen Viet
Published: October 2011

This article investigates the extent to which public and private transfers affected poverty and inequality in Vietnam in the mid‐2000s. It finds that the impact of public transfers on poverty was negligible, due to the low coverage of the poor and the relatively small amounts transferred. Moreover, the effect of the receipt of transfers on expenditures was small: recipients decreased the labour supply and only a limited amount of the extra income went to current consumption. Domestic private transfers were somewhat more successful in reducing poverty. With most public and private transfers going to non‐poor households, inequality was only marginally affected.
Synergism of pheromone and host‐plant volatile blends in the attraction of Grapholita molesta males
Authors: Varela Nélia , Avilla Jesús , Anton Sylvia , Gemeno César
Published: October 2011

Control of Grapholita molesta (Busck) (Lepidoptera: Tortricidae), a major pest of stone and pome fruits, is successfully achieved by mating disruption. Under these conditions, tools other than conventional pheromone dispensers are needed for flight monitoring. The objective of the present work was to determine whether plant volatiles synergize male G. molesta attraction to a suboptimal dose of synthetic sex pheromone. The plant blend (referred to as 5VB), a mixture of three green leaf volatiles [(Z)‐3‐hexenyl acetate, (Z)‐3‐hexenol, and (E)‐2‐hexenal] and two aromatics [benzaldehyde (BZA) and benzonitrile (BZN)], was added to the suboptimal pheromone dose (2 ng on filter paper) in log steps (up to 10 000× the pheromone dose) to test synergism of pheromone and plant blends. In addition, the effect of individual plant volatiles on male responses was investigated by adding to the suboptimal pheromone dose each of the four‐compound plant‐volatile blends, resulting from eliminating one volatile from the 5VB at a time, or each plant volatile alone. Flight behaviour and the time to reach the source were recorded. The 5VB alone was not attractive to G. molesta males, but at a ratio of 1:1 000 (Ph:5VB) or higher, the attractiveness of the suboptimal pheromone dose increased, to a level similar to that of the optimal pheromone dose (10 ng). All tested plant volatiles, except BZA, synergized the response to the pheromone when added individually, but only (Z)‐3‐hexenol and BZN did so to a level not significantly different from the Ph:5VB blend. Aromatics had a stronger effect than green leaf volatiles (GLVs), because their removal, but not the removal of GLVs, decreased landing responses. The addition of the 5VB decreased significantly the time males needed to reach the odour source. The observed enhanced male attraction to mixtures of pheromone and plant volatiles will facilitate the development of lures for G. molesta adult flight monitoring.
Human umbilical cord mesenchymal stem cells suppress breast cancer tumourigenesis through direct cell–cell contact and internalization
Authors: Chao Kuo‐Ching , Yang Hui‐Tai , Chen Min‐Wei
Published: October 2011

The purpose of this study was to investigate how human umbilical cord mesenchymal stem cells (HUMSCs) affect breast cancer tumourigenesis. To observe the influence of HUMSCs on tumourigenesis in vitro, we performed a co‐culture of MDA MB‐231 breast cancer cells with HUMSCs, and a result of HUMSCs on tumourigenesis in vivo was achieved by injection of HUMSCs into nonobese diabetic/severe combined immunodeficient mice following tumour establishment with MDA‐MB231. During the co‐culture, apoptosis of MDA‐MB231 was noted, which was driven either by binding with HUMSC through direct cell–cell contact or by formation of a novel cell‐in‐cell phenomenon after internalization of HUMSC. Also, treatment with HUMSC injection was efficacious in both in situ and metastatic breast cancers in the animal models. Since HUMSCs were proved to efficaciously suppress breast cancer tumourigenesis both in vitro and in vivo, it is our expectation that treatment with HUMSCs can be a viable therapy for breast cancer in the near future. In addition, we share a new point of view on the role of HUMSCs in foetal development during pregnancy.
THE POWER OF SENSORY DISCRIMINATION METHODS REVISITED
Authors: ENNIS JOHN M. , JESIONKA VIRGINIE
Published: October 2011

“The power of sensory discrimination methods” (PSDM) was published in this journal in 1993. PSDM clarified the need for power considerations in the interpretation of testing results while providing a series of sample size tables. Despite the fact that the data considered in PSDM were binomially distributed, a normal approximation was used that both overestimated power and underestimated sample sizes. Although exact power functions have been examined in the sensory literature, the unusual behavior of these functions has not been embraced; the fact that increasing sample size can decrease power has not yet been incorporated into stable sample size recommendations. In this paper, we provide sample size recommendations with the property that any larger sample sizes also have the desired level of power. These recommendations are given in the form of tables updating those found in PSDM. In addition, a relatively new discrimination testing method known as the tetrad test has grown in popularity recently and this test now needs to be examined from a power perspective. We show that the tetrad test is remarkably powerful for an unspecified test and in some cases only requires one third the sample size as that required by the triangle test.

PRACTICAL APPLICATIONS

This paper contains three main practical applications. First, we provide sample size recommendations, including tables, based on the exact power function as determined by the binomial distribution. In particular, this paper is the first to provide exact sample size recommendations such that all larger sample sizes continue to have the desired level of power. Next, we use the exact power analysis to recommend that only the 2‐alternative forced choice (AFC); instead of, for example, the 3‐AFC or the specified tetrad test be used for forced choice testing in which an attribute of interest is specified to distinguish the samples. Finally, we provide a power analysis of the unspecified tetrad test for the first time in the sensory literature and show that in some cases, the tetrad test only requires one third the sample size as the triangle test. This last point could lead to both significant resource savings and improved confidence for researchers throughout sensory science.
On the evolution of the sexually transmitted bacteria Haemophilus ducreyi and Klebsiella granulomatis
Authors: Lagergård Teresa , Bölin Ingrid , Lindholm Leif
Published: October 2011

Haemophilus ducreyi and Klebsiella (Calymmatobacterium) granulomatis are sexually transmitted bacteria that cause characteristic, persisting ulceration on external genitals called chancroid and granuloma inguinale, respectively. Those ulcers are endemic in developing countries or exist, as does granuloma inguinale, only in some geographic “hot spots.”H. ducreyi is placed in the genus Haemophilus (family Pasteurellacae); however, this phylogenetic position is not obvious. The multiple ways in which the bacterium may be adapted to its econiche through specialized nutrient acquisitions; defenses against the immune system; and virulence factors that increase attachment, fitness, and persistence within genital tissue are discussed below. The analysis of K. granulomatis phylogeny demonstrated a high degree of identity with other Klebsiella species, and the name K. granulomatis comb. nov. was proposed. Because of the difficulty in growing this bacterium on artificial media, its characteristics have not been sufficiently defined. More studies are needed to understand bacterial genetics related to the pathogenesis and evolution of K. granulomatis.
Study on Classification of Soy Sauce by Electronic Tongue Technique Combined with Artificial Neural Network
Authors: Ou‐Yang Qin , Zhao Jie‐Wen , Chen Quan‐Sheng , Lin Hao , Huang Xing‐Yi
Published: October 2011

Abstract:  Electronic tongue as an analytical tool coupled with pattern recognition was attempted to classify 4 different brands and 2 categories (produced by different processes) of Chinese soy sauce. An electronic tongue system was used for data acquisition of the samples. Some effective variables were extracted from electronic tongue data by principal component analysis (PCA). Backpropagation artificial neural network (BP‐ANN) was applied to build identification models. PCA score plots show an obvious cluster trend of different brands and different categories of soy sauce in the 2‐dimensional space. The optimal BP‐ANN model for different brands was achieved when principal components (PCs) were 2, and the identification rate of the discrimination model was 100% in both the calibration set and the prediction set, and the optimal BP‐ANN model for different categories had the same result. This work demonstrates that electronic tongue technology combined with a suitable pattern recognition method can be successfully used in the classification of different brands and categories of soy sauce.
Tongue abscess: a rare clinical entity
Authors: Pallagatti Shambulingappa , Sheikh Soheyl , Kaur Anupreet , Puri Nidhi , Singh Ravinder , Arya Smriti
Published: October 2011

Swelling of the tongue is a rare clinical entity. It is a potentially life‐threatening condition, as it could result in airway compromise. The differential diagnosis of acute tongue swelling includes hemorrhage, infarction, abscess, tumor, and edema. A tongue abscess should be considered in all cases of acute tongue swelling, especially when host defenses are severely impaired. Although the diagnosis of lingual abscess can be reached clinically because of the rarity of the condition, in neglected cases, the diagnosis can be difficult. Despite of the rarity and complexity of this condition, its management strategy is relatively simple. In the present study, we describe a case of a tongue abscess on the anterior two‐thirds of the tongue in a 60‐year‐old woman, and discuss the pathophysiology, diagnosis, and treatment of this complex entity.
Effect of Phonon Dispersion on Thermal Conduction Across Si/Ge Interfaces
Authors: Singh Dhruv , Murthy Jayathi Y. , Fisher Timothy S.
Published: October 2011

We report finite-volume simulations of the phonon Boltzmann transport equation (BTE) for heat conduction across the heterogeneous interfaces in SiGe superlattices. The diffuse mismatch model incorporating phonon dispersion and polarization is implemented over a wide range of Knudsen numbers. The results indicate that the thermal conductivity of a Si/Ge superlattice is much lower than that of the constitutive bulk materials for superlattice periods in the submicron regime. We report results for effective thermal conductivity of various material volume fractions and superlattice periods. Details of the nonequilibrium energy exchange between optical and acoustic phonons that originate from the mismatch of phonon spectra in silicon and germanium are delineated for the first time. Conditions are identified for which this effect can produce significantly more thermal resistance than that due to boundary scattering of phonons.
Adaptation to Climate Across the
Arabidopsis thaliana
Genome
Authors: Hancock Angela M. , Brachi Benjamin , Faure Nathalie , Horton Matthew W. , Jarymowycz Lucien B. , Sperone F. Gianluca , Toomajian Chris , Roux Fabrice , Bergelson Joy
Published: October 2011

Alleles that are under selection in
Arabidopsis
serve as genetic markers that can be used to predict local adaptation.
Digital Bias
Authors: Wong Wei
Published: October 2011

Gender differences in finger length ratios are caused by relative differences in sex hormone signaling in developing limb buds.
The Changing Burden of Infectious Disease in Europe
Authors: Fears Robin , van der Meer Jos W. M. , ter Meulen Volker
Published: October 2011

Opportunities and challenges are described for improving disease surveillance and health care innovation to tackle the growing threats of infection.
Comparison of Abortion and Infection after Experimental Challenge of Pregnant Bison and Cattle with Brucella abortus Strain 2308
Authors: Olsen S. C. , Johnson C.
Published: October 2011

A comparative study was conducted using data from naive bison (n= 45) and cattle (n= 46) from 8 and 6 studies, respectively, in which a standardizedBrucella abortusstrain 2308 experimental challenge was administered during midgestation. The incidence of abortion, fetal infection, uterine or mammary infection, or infection in maternal tissues after experimental challenge was greater (P< 0.05) in bison than in cattle. In animals that did abort, the time between experimental challenge and abortion was shorter (P< 0.05) for bison than for cattle.Brucellacolonization of four target tissues and serologic responses on the standard tube agglutination test at the time of abortion did not differ (P> 0.05) between cattle and bison. The results of our study suggest that naive bison and cattle have similarities and differences after experimental exposure to a virulentB. abortusstrain. Although our data suggest that bison may be more susceptible to infection withBrucella, some pathogenic characteristics of brucellosis were similar between bison and cattle.
Darwin’s legacy: why biology is not physics, or why evolution has not become a common sense1Award Lecture, Genetics Society of Canada P. Moens and W.F. Grant Award of Excellence, 2010. / Conférence du récipiendaire, Prix d’excellence P. Moens et W.F. Grant de la Société de Génétique du Canada, 2010.
Authors: Singh Rama S.
Published: October 2011

Cosmology and evolution together have enabled us to look deep into the past and comprehend evolution—from the big bang to the cosmos, from molecules to humans. Here, I compare the nature of theories in biology and physics and ask why physical theories get accepted by the public without necessarily comprehending them but biological theories do not. Darwin’s theory of natural selection, utterly simple in its premises but profound in its consequences, is not accepted widely. Organized religions, and creationists in particularly, have been the major critic of evolution, but not all opposition to evolution comes from organized religions. A great many people, between evolutionary biologists on one hand and creationists on the other, many academics included, who may not be logically opposed to evolution nevertheless do not accept it. This is because the process of and the evidence for evolution are invisible to a nonspecialist, or the theory may look too simple to explain complex traits to some, or because people compare evolution against God and find evolutionary explanations threatening to their beliefs. Considering how evolution affects our lives, including health and the environment to give just two examples, a basic course in evolution should become a required component of all our college and university educational systems.
Effect of Porosity on Cycle Performance in Three-Dimensional Disk Electrode for Li Ion Battery
Authors: Ahn Cheol-Woo , Hahn Byung-Dong , Park Dong-Soo , Sung Yung-Eun
Published: October 2011

A new three-dimensional disk electrode structure was designed without Cu foil for the anode of Li-ion battery. In this structure, the weight ratio of active material could be decided by controlling the particle size ratio between active material and current collector. 0.6Cu–0.4CoO composite (40% weight ratio of CoO) was prepared by conventional ceramic process. The excellent operation of three-dimensional disk electrode for Li-ion battery was clarified. Its porosity must be lower than 26%, in order to obtain the high adhesion between Cu and CoO particles.
A Compact Model for Channel Coupling in Sub-30 nm NAND Flash Memory Device
Authors: Kang Myounggon , Hahn Wookghee , Park Il Han , Song Youngsun , Lee Hocheol , Choi Kihwan , Lim Youngho , Joe Sung-Min , Chae Dong Hyuk , Shin Hyungcheol
Published: October 2011

This paper presents an analytic model for NAND flash array where channel coupling embodies. Channel coupling effect which is becoming a more serious issue in developing high-density flash memory devices should be effectively suppressed. By applying the coupling model to a 30-nm NAND flash product, the simulation showed a good agreement with the measurement results. Also, complex problems in scaled NAND flash memories could be accurately explained by circuit simulations. This evaluation will be useful in developing high-density multi-level cell (MLC) NAND flash technologies.
Fabrication of Au Microelectrodes with Photopolymerization of Triazine Dithiol Thin Films
Authors: Sato Yuya , Ye Rongbin , Ohta Koji , Baba Mamoru
Published: October 2011

In this article, we report a new lift-off process to fabricate Au microelectrodes with photopolymerization of 6-diallylamino-[1,3,5]triazine-2,4-dithiol (DA) thin films, which is easier, more energy saving, and friendlier to the environment than the past processes. The optimum conditions for fabricating fine Au/poly(DA) microelectrodes are as follows: DA film thickness is 40 nm and UV irradiation time is 20 min. The Au/poly(DA) microelectrodes with over 10 µm spaces were developed and could be well applied to pentacene thin-film transistors with a mobility of 1.3×10-1 cm2 V-1 s-1 and a threshold voltage of -13.4 V.
Frequency Modulation Response of a Liquid Crystal Electrooptic Device Doped with Guanine Oligonucleotides
Authors: Sawada Norihiro , Iwabata Kazuki , Ino Keita , Sugai Urara , Seki Yasutaka , Kakinuma Daisaku , Furue Hirokazu , Takatoh Kohki , Kobayashi Shunsuke , Sakaguchi Kengo
Published: October 2011

We have fabricated a twist nematic liquid crystal (TN) cell doped with guanine oligonucleotide (G10b) and measured its voltage-dependent transmittance (V–t) response. It is found that the operating voltage of a TN cell doped with G10b is higher than that of an undoped cell at 10 Hz. At a high frequency above 100 Hz, the V–t curve tends toward a saturated value equivalent to that of an undoped cell. The increase in the operating voltage depends on the concentration of G10b. This result suggests that G10b acts as an ion and produces an opposing electrical field between the electrodes.
Electrochemical Fabrication of Titanium Oxide Film from an Aqueous Solution Containing Titanium Ion and Hydroxylamine
Authors: Ishizaki Hiroki , Ito Seishiro
Published: October 2011

TiO2 films with poly crystal were electrodeposited on conductive substrate (NESA glass, Approximately 10Ω/□, Asahi glass Co. Ltd.) from the titanium potassium oxalate dehydrate aqueous solution containing hydroxylamine adjusted pH 9 with KOH aq. at 333k. The peak corresponded to Ti3+ion into these TiO2 film was not observed by using X-ray photoelectron spectroscopy (XPS). The photocatalysis of TiO2 film increased with a decrease of cathodic potential. In particular, TiO2 film obtained at cathodic potential of -1.3V, had the higher photocatalysis than that of other potential.
Effects of Post-Deposition Annealing Atmosphere and Duration on Sol-Gel Derived Amorphous Indium-Zinc-Oxide Thin-Film Transistors
Authors: Chung Wan-Fang , Chang Ting-Chang , Li Hung-Wei , Tseng Tseung-Yuen , Tai Ya-Hsiang
Published: October 2011

This work shows the effects of post-deposition annealing atmosphere and duration on the properties of sol-gel derived amorphous indium zinc oxide thin film transistors (a-IZO TFTs). Two different post-deposition annealing atmospheres, nitrogen and oxygen, were used in this study. Experimental results showed that the O2-annealed devices showed better electrical characteristics than the N2-annealed samples. Under O2-annealing, field effect mobility was enhanced to 1.47 cm2/V s, the threshold voltage increased to -4.61 V and the subthreshold swing improved to 0.86 V/dec. Also, the transfer characteristics of a-IZO TFTs improve with annealing time. X-ray photoelectron spectroscopy (XPS) analysis indicated that the chemical composition of the IZO film was modified by the oxygen annealing.
Metal Electrode Contact Cleaning in Small Dimension Phase Change Memory
Authors: Bae JinHye , Lee WonJun , Chung DaeHyuk , Hwang InSeak , Ahn DongHo , Nam Seok Woo
Published: October 2011

It is necessary to be studied attributes for controlling interface resistance especially in dash type small metal contact for high performance phase change memory cell. In this study, we will discuss about the metal electrode interface cleaning by using SC1, HF cleanings and NH3 plasma treatment. On electrode metal surface, SC1, HF cleanings and NH3 plasma combined treatment is most effective for the interface ohmic condition. Cross sectional view TEM data shows that the interface unknown substances were not seen. This is because SC1, HF cleaning and plasma treatment removes the metal residue acting as a lift off agent and reduces metal oxide complexes during in annealing process.
Galvanic Corrosion of PN Junctions during the Dielectric Removal with HF for RMG Transistors
Authors: Pacco Antoine , Sebaai Farid , Suhard Samuel , Struyf Herbert , De Gendt Stefan , Vos Rita , Veloso Anabela , Mertens Paul W.
Published: October 2011

For the high-k-last integration scheme both dummy poly-gate and dummy dielectric have to be removed before deposition of the novel metal gate. In this paper we will focus on the wet removal of the dummy dielectric by diluted HF selectively towards the silicon channel. Diluted HF is the chemical of choice due to its high selectivity towards silicon. In some cases however, the channel is attacked during this wet process step. Galvanic corrosion was identified as the detrimental mechanism for this attack. In this work a more detailed explanation of electrochemical corrosion behavior of doped silicon is given and compared with the observed results in devices. The silicon loss in the device samples is in good agreement with the experimentally obtained silicon loss measured for some non-device samples.
Effect of Dissolved CO2 in De-Ionized Water in Reducing Wafer Damage During Megasonic Cleaning in MegPie
Authors: Kumari Sangita , Keswani Manish , Singh Satish , Beck Mark , Liebscher Eric , Toan L. Q. , Raghavan Srini
Published: October 2011

Particle removal from wafer surfaces can be accomplished by irradiation of cleaning fluid by sound waves in the MHz frequency range. Unfortunately, unless proper cleaning conditions are chosen, megasonic irradiation may also result in damage to fragile wafer features. Here, we demonstrate a strong effect of dissolved CO2 levels on the reduction of wafer damage during megasonic cleaning. Test structures with L/S patterns were irradiated with 0.93 MHz sound waves at varying power densities and dissolved CO2 levels, in a single wafer spin cleaning tool, MegPie®. Dissolution of increasing amounts of CO2 in air saturated DI water caused a significant decrease in the number of breakages to line structures and also decreased the lengths of the line breakages, at all power densities up to 2.94 W/cm2. This ability of dissolved CO2 to protect against feature damage correlates well with its ability to suppress sonoluminescence in sound irradiated DI water.
Effect of Acoustic Cavitation on Dissolved Gases and their Characterization during Megasonic Cleaning
Authors: Kang Bong-Kyun , Kim Min-Su , Lee Seung-Ho , Sohn Hongseong , Park Jin-Goo
Published: October 2011

In this study, both cleaning performance and pattern damage events were evaluated for specific gases (H2, N2, O2 and Ar) dissolved deionized water (g-DIW) with megasonic (MS). The particle removal ability of all g-DIW with MS was gradually increased with their gasification level risen up. The evaluation of pattern damage was performed on PR line pattern that line width is 300 nm. Results showed a similar trend just like the PRE test. Especially H2 dissolved DI water (H2-DIW) showed the most effective particle removal efficiency (PRE), but it generated lots of damage events than others. In order to clarify the differences of MS cleaning performance as functions of gas types and concentration in g-DIW, the mechanism of bubble nucleation, growth and cavitation effect were theoretically studied with physical properties of dissolved gas under acoustic field. From this result, their relationship with MS could be demonstrated.
Lattice Boltzmann Simulation of Cavitation and Particle Behavior Induced by Sonication Transducer
Authors: Kim Hojoong , Kim Tae-Sung
Published: October 2011

In the semiconductor process, cleaning wafer surface by megasonic transducer with thin liquid film is getting more attention than conventional bath-type batch cleaner. Although its major contribution to the cleaning process, nanoparticle removal mechanism of megasonic cleaning is not fully understood yet. Thus the understanding of the cavitation bubble motion formed by megasonic wave is very important. Due to rapid motion of the bubbles experimental observation of their movement is hard to achieve. In present study, we introduce lattice Boltzmann method to simulation fluid and cavitation bubble behavior. Validation was achieved by compare the simulation result with analytical solution of fluid motion. It was shown that bubbles formed by cavitation phenomena can be expanded, shrunken, or even collapsed to emit shockwave.
Design, Fabrication, and Performance Test of a Quartz Horn Megasonic Waveguide for Semiconductor Cleaning
Authors: Kim Hyunse , Lee Yanglae , Lim Euisu
Published: October 2011

A quartz horn megasonic waveguide for semiconductor cleaning was developed. Design and fabrication processes with a performance test are explained. A finite element analysis was performed using ANSYS for the design process. The predicted anti-resonance frequency of the quartz waveguide with a lead zirconate titanate (PZT) actuator was 1002 kHz, which agreed well with the measured value of 1003 kHz. Using this analysis results, the waveguide was fabricated with quartz. To assess the system performance, acoustic pressures were measured. The results of measurement showed well-distributed acoustic pressure output. Finally, preliminary particle removal efficiency (PRE) tests were carried out with different input powers between 0.5 W and 7 W. The number of particles was counted using a particle counting machine, and over 90% particles was removed with more than 1 W power supply. These results suggest that the developed quartz horn megasonic system can be used for semiconductor cleaning process.
Optimization of DIO3 with Megasonic Cleaning of Ru Capped EUVL Mask for Effective Carbon Contaminant Removal
Authors: Lee Seung-Ho , Kang Bong-Kyun , Kim Min-Su , Lim Jung-Soo , Jeong Ji-Hyun , Park Jin-Goo
Published: October 2011

A possible candidate for carbon contaminant removal in Ru capped EUVL mask is ozone dissolved water (DIO3). However, the use of DIO3 leaves reflectivity loss and serious surface damages on Ru capping layer caused by its high oxidation potential. In this study, an optimum DIO3 cleaning condition for effective carbon cleaning without surface damage was investigated both theoretically and experimentally. The effect of additive gases such as O2, CO2 and N2 of various concentrations were tried during DIO3 generation for oxidation stability on Ru capping layer and N2 added 15 ppm DIO3 was found to be the best condition. However carbon contaminant was ineffectively removed at this condition. Thus megasonic is irradiated during DIO3 process and the results show that carbon is not only completely removed in a shorter time but also lower reflectivity loss was accomplished with minimal increase in the surface roughness.
Processing of Mechanically Polished Surfaces of Bulk GaN Substrates
Authors: Nowak Grzegorz , Kamler Grzegorz , Weyher Janusz L , Grzegory Izabella
Published: October 2011

The paper is concerned with mechano-chemical processing of mechanically polished GaN wafers. Key fundamental properties and device applications of GaN are reviewed emphasizing versatility of this compound in carrying out both electronic and photonic functions. Subsequently, methods used to process mechanically polished GaN surfaces in preparation for epitaxial deposition of thin GaN layers are discussed. The review is supported by original results obtained in the course of extensive experiments focused on the processes aimed at the removal of the polishing damage from GaN surface.
SiGe Alloys Sensitivity to Front-End Surface Preparations
Authors: Briend Guillaume , Garnier Philippe , Jeanjean Damien , Breil Nicolas , Gourhant Olivier , Dutartre Didier , Tanon-Pellissier Denis , Campidelli Yves , Bidal Gregory , Levy Didier
Published: October 2011

In this article, focus has been made on two topics: the SiGe sensitivity to wet Front-End-Of-Line (FEOL) surface preparations and the SiGe/Oxide interface. Depending on the FEOL cleaning process, the chemical oxide growth on SiGe and the associated consumption can be tuned in order to precisely control the oxide thickness and the material loss. In this case, HF last surface preparation presents good performances but his final hydrogen passivation gives a SiGe surface too sensitive to furnace oxidation steps. Using SIMS, AR-XPS and AFM analyses, we show a Ge segregation at the interface or/and a Stranski-Krastanov (SK) relaxation. Finally, a wet clean process with a final hydroxyl passivation is preferred and presents a good compromise between material loss, chemical oxide growth and roughness at the SiGe/Oxide interface.
Investigation on the Drying Dynamics of Millimetric Water Droplets: Source of Watermarks on Silicon Wafers
Authors: Belmiloud Naser , Tamaddon Amir-Hossein , Mertens Paul W. , Xu Xiumei , Struyf Herbert
Published: October 2011

Evaporation of unpinned sessile droplets with small contact angles (below 90°) is studied here extensively. We focused our work on the constant contact-angle mode in which the contact area of the droplet on the substrate decreases. A thorough understanding of droplet evaporation is of vital importance for examining the drying rate, the flow patterns observed inside drying drops, and the residual deposits. The concentration of each potential dissolved species (e.g. silica or silicic acid) can also be predicted and confronted to their solubility. We developed a theoretical model to predict the evaporation rate and the behavior of millimetric droplets taking into account the characteristics of the ambient and the substrate during the drying process. We discuss also the topology of watermarks on silicon wafers in the case of a predominant evaporation phenomenon.
Effect of Pump Pulsation on Particle Contamination on Wafer Surface in Wet Cleaning System
Authors: Lim Jung-Soo , Venkatesh Rajaraman Prasanna , Park Jin-Goo
Published: October 2011

The effects of pumping method on wafer cleaning were investigated. Two types of pump such as diaphragms and centrifugal were used for circulation and supply of DI water for wafer cleaning in both wet bath and single wafer tool. The cleaning studies show that the pumping methods have a great influence on cleaning performance. The experimental investigations reveal that the number of added particles on the wafer during wafer cleaning is much lesser in MLC pump (non-pulsation flow) than the both diaphragm pumps (pulsation flow).
Optimization of CO2 Gas Cluster Generation for Cleaning Application
Authors: Choi Hoomi , Kim Hojoong , Yoon Deok-Joo , Lee Jongwoo , Kang Bong-Kyun , Kim Min-Su , Park Jin-Goo , Kim Tae-Sung
Published: October 2011

In this paper, optimization method for gas cluster generation was studied both theoretically and experimentally for a new dry cleaning process using gas cluster beam. Since the typical size of gas cluster is less than 50 nm, it is expected to cause no damage on the surface. CO2 gas cluster cleaning system was built to evaluate the feasibility of the cleaning by gas cluster beam, which is generated by expansion through the converging-diverging nozzle and chilling. Cleaning test was performed for 25 nm silica particle cleaning on a bare Si wafer, and on a wafer with 80 nm poly-silicon structure. Preliminary result has been obtained, which showed that we could achieve cleaning of contaminants without damage. To optimize the gas cluster cleaning process, we propose the use of particle beam mass spectrometer (PBMS) for the measurement of size distribution and numerical simulation of gas cluster generation process.
Plasma Strip of Cold Implant Photoresist
Authors: Luo Shijian , Waldfried Carlo , Berry Ivan , Roh Dwight
Published: October 2011

This paper reports on the formation of highly carbonized crust layer on top of high dose implanted photoresist (PR) at cold implant temperature (-50°C) as well as room temperature. The differences between the crusts formed at different implant temperatures and the effects to the subsequent resist plasma strip were investigated. Thinner crust formed at cold implant temperature led to faster and more uniform crust and PR removal. The changes of the photoresist chemical bonding after ion implantation at different temperatures were also studied, and difference of chemical bonding between resist wafers implanted at different temperature was observed. Test results demonstrated that the resist implanted at cold temperature beneficially affects crust formation and PR plasma strip processes.