bluuebunny/crossref_metadata_2025 huggingface dataset:
Population status, structure and distribution of the greater one-horned rhinoceros Rhinoceros unicornis in Nepal
Authors: Subedi Naresh , Jnawali Shant Raj , Dhakal Maheshwar , Pradhan Narendra M.B. , Lamichhane Babu Ram , Malla Sabita , Amin Rajan , Jhala Yadvendradev V.
Published: July 2013

We assessed the abundance and distribution of the greater one-horned or Indian rhinoceros Rhinoceros unicornis in all its potential habitats in Nepal, using block counts. In April 2011 5,497 km were searched in 3,548 elephant-hours over 23 days. The validity of the block count was assessed by comparing it with counts obtained from long-term monitoring using photographic identification of individual rhinoceroses (ID-based), and estimates obtained by closed population sighting–mark–resighting in the 214 km2 of Chitwan National Park. A total of 534 rhinoceroses were found during the census, with 503 in Chitwan National Park (density 1 km−2), 24 in Bardia National Park (0.28 km−2) and seven in Suklaphanta Wildlife Reserve (0.1 km−2). In Chitwan 66% were adults, 12% subadults and 22% calves, with a female : male ratio of 1.24. The population estimate from sighting–mark–resighting was 72 (95% CI 71–78). The model with different detection probabilities for males and females had better support than the null model. In the Sauraha area of Chitwan estimates of the population obtained by block count (77) and ID-based monitoring (72) were within the 95% confidence interval of the estimate from sighting–mark–resighting. We recommend a country-wide block count for rhinoceroses every 3 years and annual ID-based monitoring in a sighting–mark–resighting framework within selected subpopulations. The sighting–mark–resighting technique provides the statistical rigour required for population estimates of the rhinoceros in Nepal and elsewhere.
The methods and outcomes of cultural adaptations of psychological treatments for depressive disorders: a systematic review
Authors: Chowdhary N. , Jotheeswaran A. T. , Nadkarni A. , Hollon S. D. , King M. , Jordans M. J. D. , Rahman A. , Verdeli H. , Araya R. , Patel V.
Published: July 2013

Background

Cultural adaptations of evidence-based psychological treatments (PTs) are important to enhance their universal applicability. The aim of this study was to review systematically the literature on adaptations of PTs for depressive disorders for ethnic minorities in Western countries and for any population in non-Western countries to describe the process, extent and nature of the adaptations and the effectiveness of the adapted treatments.

Method

Controlled trials were identified using database searches, key informants, previous reviews and reference lists. Data on the process and details of the adaptations were analyzed using qualitative methods and meta-analysis was used to assess treatment effectiveness.

Results

Twenty studies were included in this review, of which 16 were included in the meta-analysis. The process of adaptation was reported in two-thirds of the studies. Most adaptations were found in the dimensions of language, context and therapist delivering the treatment. The meta-analysis revealed a statistically significant benefit in favor of the adapted treatment [standardized mean difference (SMD) −0.72, 95% confidence interval (CI) −0.94 to −0.49].

Conclusions

Cultural adaptations of PTs follow a systematic procedure and lead primarily to adaptations in the implementation of the treatments rather than their content. Such PTs are effective in the treatment of depressive disorders in populations other than those for whom they were originally developed.
Cognitive functioning in obsessive-compulsive disorder: a meta-analysis
Authors: Shin N. Y. , Lee T. Y. , Kim E. , Kwon J. S.
Published: July 2013

Background

Substantial empirical evidence has indicated impairment in the cognitive functioning of patients with obsessive-compulsive disorder (OCD) despite inconsistencies. Although several confounding factors have been investigated to explain the conflicting results, the findings remain mixed. This study aimed to investigate cognitive dysfunction in patients with OCD using a meta-analytic approach.

Method

The PubMed database was searched between 1980 and October 2012, and reference lists of review papers were examined. A total of 221 studies were identified, of which 88 studies met inclusion criteria. Neuropsychological performance and demographic and clinical variables were extracted from each study.

Results

Patients with OCD were significantly impaired in tasks that measured visuospatial memory, executive function, verbal memory and verbal fluency, whereas auditory attention was preserved in these individuals. The largest effect size was found in the ability to recall complex visual stimuli. Overall effect estimates were in the small to medium ranges for executive function, verbal memory and verbal fluency. The effects of potentially confounding factors including educational level, symptom severity, medication status and co-morbid disorders were not significant.

Conclusions

Patients with OCD appear to have wide-ranging cognitive deficits, although their impairment is not so large in general. The different test forms and methods of testing may have influenced the performance of patients with OCD, indicating the need to select carefully the test forms and methods of testing used in future research. The effects of various confounding variables on cognitive functioning need to be investigated further and to be controlled before a definite conclusion can be made.
On ‘Activation Workers' Perceptions’: A Reply to Dunn (1)
Authors: MARSTON GREG
Published: July 2013

Andrew Dunn challenges social policy researchers to include the perspectives of other policy actors in the debate about the merits and limits of activation policies that emphasise greater conditionality for those in receipt of benefits. In his provocative article, he focuses on the views and experiences of people who work with unemployed people. His study focuses on a sample of forty employment advisers in the UK and his particular interest is in their attitudes about unemployment and the unemployed, particular their views on the ‘welfare dependency’ thesis. While his discussion of these issues is interesting and engaging, there are a number of limitations that deserve further discussion.
Immune–wavelet optimization for path planning of large-scale robots
Authors: Asadi Saeid , Azimirad Vahid , Eslami Ali , Eghbal Saeid Karimian
Published: July 2013

In this paper an optimal path planning method based on a new evolutionary algorithm is presented for higher order robotic systems. It is a combination of immune system and wavelet mutation. By increasing the system's dimensions, the complexity of algorithm grows linearly. The obtained results have been compared with other optimal path producing algorithms, and its excellence in terms of optimality has been proved. Strengths of this method are simplicity in large-scale path planning, being free of most of the common deadlocks in usual method, and ability to obtain more optimized results than other similar methods. The effectiveness of this approach on simulation case studies for a three-link planar robot and 5 degrees of freedom mobile manipulators as well as an experiment for a mobile robot called K-joniour is shown.
Grasp planning and parallel control of a redundant dual-arm/hand manipulation system
Authors: Caccavale Fabrizio , Lippiello Vincenzo , Muscio Giuseppe , Pierri Francesco , Ruggiero Fabio , Villani Luigi
Published: July 2013

In this paper, a kinematic model of a dual-arm/hand robotic system is derived, which allows the computation of the object position and orientation from the joint variables of each arm and each finger as well as from a suitable set of contact variables. On the basis of this model, a motion planner is designed, where the kinematic redundancy of the system is exploited to satisfy some secondary tasks aimed at ensuring grasp stability and manipulation dexterity without violating physical constraints. To this purpose, a prioritized task sequencing with smooth transitions between tasks is adopted. Afterwards, a controller is designed so as to execute the motion references provided by the planner and, at the same time, achieve a desired contact force exerted by each finger on the grasped object. To this end, a parallel position/force control is considered. A simulation case study has been developed by using the dynamic simulator GRASPIT!, which has been suitably adapted and redistributed.
UAV-borne X-band radar for collision avoidance
Authors: Moses Allistair , Rutherford Matthew J. , Kontitsis Michail , Valavanis Kimon P.
Published: July 2013

The increased use of unmanned aerial vehicles (UAVs) is coincidentally accompanied by a notable lack of sensors suitable for enabling further improvement in levels of autonomy and, consequently, integration into the National Airspace System (NAS). The majority of available sensors suitable for UAV integration into the NAS are based on infrared detectors, focal plane arrays, optical and ultrasonic rangefinders, etc. These sensors are generally not able to detect or identify other UAV-sized targets and, when detection is possible, considerable computational power is typically required for successful identification. Furthermore, the performance of visual-range optical sensor systems may suffer when operating under conditions that are typically encountered during search and rescue, surveillance, combat, and most other common UAV applications. However, the addition of a miniature RADAR sensor can, in consort with other sensors, provide comprehensive target detection and identification capabilities for UAVs. This trend is observed in manned aviation where RADAR sensors are the primary on-board detection and identification sensors. In this paper, a miniature, lightweight X-band RADAR sensor for use on a miniature (710-mm rotor diameter) rotorcraft is described. We present an analysis of the performance of the RADAR sensor in a realistic scenario with two UAVs. Additionally, an analysis of UAV navigation and collision avoidance behaviors is performed to determine the effect of integrating RADAR sensors into UAVs. Further study is also performed to demonstrate the scalability of the RADAR for use with larger UAV classes.
IMM-UKF-TFS Model-based Approach for Intelligent Navigation
Authors: Malleswaran M. , Vaidehi V. , Irwin S. , Robin B.
Published: July 2013

This paper aims to introduce a novel approach named IMM-UKF-TFS (Interacting Multiple Model-Unscented Kalman Filter-Two Filter Smoother) to attain positional accuracy in the intelligent navigation of a manoeuvring vehicle. Here, the navigation filter is designed with an Unscented Kalman Filter (UKF), together with an Interacting Multiple Model algorithm (IMM), which estimates the state variables and handles the noise uncertainty of the manoeuvring vehicle. A model-based estimator named Two Filter Smoothing (TFS) is implemented along with the UKF-based IMM to improve positional accuracy. The performance of the proposed IMM-UKF-TFS method is verified by modelling the vehicle motion into Constant Velocity-Coordinated Turn (CV-CT), Constant Velocity – Constant Acceleration (CV-CA) and Constant Acceleration-Coordinated Turn (CA-CT) models. The simulation results proved that the proposed IMM-UKF-TFS gives better positional accuracy than the existing conventional estimators such as UKF and IMM-UKF.
An update on frailty diagnosis and management
Authors: Deane Andrew JB , Jaafar Ahmed F
Published: July 2013

Frailty as a clinical syndrome is becoming more widely recognized and current evidence shows the importance of early detection of pre-frail states with a potential for reversibility of poor outcomes. The purpose of this review is to present the latest literature on frailty since the last review in this journal in 2007, with a particular focus on interventions aimed at reversing the processes of frailty.
Perceived Parental Rearing Behaviours, Responsibility Attitudes and Life Events as Predictors of Obsessive Compulsive Symptomatology: Test of a Cognitive Model
Authors: Haciomeroglu Bikem , Karanci A. Nuray
Published: July 2013

Background: It is important to investigate the role of cognitive, developmental and environmental factors in the development and maintenance of Obsessive Compulsive Symptomatology (OCS). Aims: The main objective of this study was to examine the vulnerability factors of OCS in a non-clinical sample. On the basis of Salkovskis’ cognitive model of OCD, the study aimed to investigate the role of perceived parental rearing behaviours, responsibility attitudes, and life events in predicting OCS. Furthermore, the mediator role of responsibility attitudes in the relationship between perceived parental rearing behaviours and OCS was examined. Finally, the specificity of these variables to OCS was evaluated by examining the relationship of the same variables with depression and trait anxiety. Method: A total of 300 university students (M = 19.55±1.79) were administered the Padua Inventory-Washington State University Revision, Responsibility Attitudes Scale, s-EMBU (My memories of upbringing), Life Events Inventory for University Students, Beck Depression Inventory, and State-Trait Anxiety Inventory-Trait Form. Results: Regression analysis revealed that perceived mother overprotection, responsibility attitudes and life events significantly predicted OCS. Furthermore, responsibility attitudes mediated the relationship between perceived mother overprotection and OCS. The predictive role of perceived mother overprotection and the mediator role responsibility attitudes were OCS specific. Conclusions: The findings of the present study supported that perceived mother over-protection as a developmental vulnerability factor significantly contributed to the explanation of a cognitive vulnerability factor (namely responsibility attitudes), and perceived maternal overprotection had its predictive role for OCS through responsibility attitudes.
Acknowledgements
Authors: Wang Helen , Hansen Valerie
Published: July 2013

The idea for this project was Helen Wang's. At the International Symposium of Ancient Coins and the Culture of the Silk Road, organised by the Shanghai Museum, in December 2006, she asked Rong Xinjiang and Valerie Hansen if they would be interested in working together on the theme of textiles as money on the Silk Road. Too often, money is assumed to mean metal coins, and the abstract concept of the Silk Road is used to evoke a somewhat ethereal east-meets-west context. While the idea of silk as money is not new to those who know Chinese history, it seemed that few people had really explored the mechanics of how textiles were used in this way.
Introduction
Authors: HANSEN VALERIE , WANG HELEN
Published: July 2013

Most economists and historians today conceive of money in narrow terms – probably because they have grown up in the modern world and are used to our system of coins, paper notes, cheques and credit cards. Although economic historians are generally aware that some earlier societies (in Africa, Scandinavia and elsewhere) used other items as money, they do not usually pay much attention to these examples. Few realise that the government of China, governing an empire of some 60 million people during the Tang dynasty (618–907), implemented a complex financial system that recognised grain, coins and textiles as money. The government received taxes in coin and in kind, produced to specific standards (specific widths and lengths of textiles) that would then be redistributed, being used for official salaries and military expenses among other expenditures. Although some of the surviving evidence comes from the Silk Road sites of Turfan, Dunhuang and Khotan in northwest China (where the dry climate has preserved many documents and some actual examples of tax textiles), this multicurrency system was in use throughout the entire empire during the seventh to tenth centuries. At the time, Tang China was possibly the largest economy in the world, rivalled only by the Abbasid Empire (751–1258).
Determining the Value of Textiles in the Tang Dynasty In Memory of Professor Denis Twitchett (1925–2006)
Authors: SHENG ANGELA
Published: July 2013

How did people in Tang dynasty China view textiles and how did they conceive of their value? Those involved in production could calculate the value in terms of the costs of raw materials, labour and the loom used to weave a particular textile. They might add to this the costs of workshop supervision and maintenance, distribution and marketing, and they might expect to see some benefit – a profit – in the process. However, most people would be end users, and would reckon the value of textiles by eye, if not also by hand, and what they considered to be the market value. Some might have expert knowledge, but many would not. The non-expert evaluation by eye and hand would likely include aspects such as colour, pattern, level of workmanship and intricacy but would probably also reflect some awareness of status and fashion.
The Demise of Silk on the Silk Road: Textiles as Money at Dunhuang from the Late Eighth Century to the Thirteenth Century
Authors: TROMBERT ERIC
Published: July 2013

The extensive documentary evidence collected and analysed in the previous studies in this issue suggest a preliminary conclusion that can be summarised as follows: from the collapse of the Han dynasty to the glorious days of the Tang dynasty, the peoples living in the Western Regions along the Silk Road used multiple co-existing forms of money – grain, cloth and coins – with one of these three items becoming predominant according to changes in political and/or economic circumstances. However, this multicurrency system did not outlive the political, economic and fiscal upheavals that shook the Tang empire from the mid-eighth century onwards. As far as the materials from Turfan and Dunhuang are concerned, the latest evidence for this monetary system is provided by a manuscript found at Dunhuang (P 3348 V°), already quoted in Arakawa Masaharu's article, which permits us to see how such a complex monetary system worked in real life once the silk shipped by the Tang government arrived in the Western Regions. In particular, a subsidiary account (P 3348 V°2 B) inscribed in this accounting report reveals how a local official called Li Jingyu 李景玉, who was vice-commissioner in the army stationed in that region, received his salary for the first semester of the year 745 ce.
Consumption of foods with voluntary fortification of micronutrients in southern Brazil: prevalence and associated factors
Authors: Cirino Ana Carolina Lima , de Vargas Zanini Roberta , Gigante Denise Petrucci
Published: July 2013

Objective

To investigate the consumption of foods with voluntary fortification of vitamins and minerals (FVFVM) according to demographic, socio-economic and health characteristics.

Design

A cross-sectional population-based study.

Setting

The investigated food groups were selected in two stages according to availability of food in the local market and prevalence of food consumption in a recent national survey. The research instruments included a questionnaire and a photographic catalogue. The FVFVM consumption covered a period of one week prior to the interview date. Statistical analyses were performed using Stata 12·0 statistical software package, considering the design effect and a hierarchical model. A multinomial logistic regression was applied to estimate the prevalence ratios. All tests were two-tailed, with a 5·0 % significance level.

Subjects

Adults (≥20 years old) living in a southern city of Brazil.

Results

Between February and June 2012, 2925 individuals were interviewed. Losses and refusals corresponded to 13·4 % of the sample. The overall prevalence of FVFVM consumption was 73·3 (95 % CI 71·7, 75·9) %. The total number of FVFVM reported exhibited a distribution with a median of two and a maximum of fifteen, inflated by the FVFVM categorized in the ‘juice’ group. The micronutrients most consumed were vitamin C, followed by Fe and thiamin. Young adults, females, those of higher socio-economic status and those who perceived their health positively were more likely to consume FVFVM.

Conclusions

Prevalence of FVFVM consumption in southern Brazil, occurring concurrently with the decline in consumption of unprocessed and minimally processed foods, and the way voluntary fortification is being employed trigger a warning sign to primary prevention.
As Clear as a Cell: Researchers See Deeper into Tissue than Ever Before
Authors: Brinkman Brendan
Published: July 2013

Researchers have long sought to visualize neural projections and other features of animal brains by imaging them using light microscopes. Connectomics studies strive to elucidate the connections among nerve cells, but brain is dense, and gray matter is tremendously light-scattering. So scientists have not been able to peer as deeply into brain tissue as is necessary to view its complex connections and structures without cutting brain tissue into thin sections. The slicing causes damage that makes it even more difficult to reconstruct exactly how nervous system structures are interconnected. Issues with light scattering have also limited studies of microvasculature, developmental structures, and other features in mouse embryos and other tissues. Traditional methods of retrograde or anterograde labeling have been able to provide high specificity of connection circuitry, but at the price of losing the organizational context of the network. In addition, there is a limit to the practical number of labels that can be used at once. Even multicolor methods have required serial section reconstruction.
Equipment Funding Opportunities and Strategies for Success (Part 6)
Authors: Liu Christina
Published: July 2013

Thanks very much for the opportunity to speak to you about Shared and High-End Instrumentation Programs at the NIH. There are differences and overlaps among the instrumentation programs in different government agencies. I hope you will find my presentation informative. The Shared and High-End Instrumentation Grant Programs (SIG/HEI) have been administered by the National Center for Research Resources (NCRR) since their inception in 1982, more than 30 years ago by Dr. Marjorie Tingle who retired in September of 2011. After the dissolution of NCRR at the end of 2011, SIG/HEI Programs were moved to NIH's Office of Research Infrastructure Programs (ORIP) under the Division of Program Coordination, Planning, and Strategic Initiatives (DPCPSI) in Office of the Director (OD). The current Program Director of the SIG/HEI is Dr. Abraham Levy. These programs provide funds to research laboratories to purchase or upgrade expensive equipment too costly to obtain with regular NIH grants. SIG Program provides funds for the cost range of $100,000–$600,000, and HEI Program provides funds from $750K–$2M.
Calendar
Authors: Webster Paul
Published: July 2013

Following is a list of microscopy related meetings and courses. The editors would greatly appreciate input to this list via the electronic submission form under “events/other microscopy events” at the MSA webpage: www.microscopy.org. We will gladly add hypertext links to the notice on the web and insert a listing of the meeting in the next issue.
What's in a 'NYM?
Authors: Keller Bob
Published: July 2013

The field of electron microscopy, by its diverse nature, abounds with acronyms: AEM, EF-TEM, ESEM, FE-SEM, HREM, HRTEM, HVEM, SEM, STEM, TEM, and VP-SEM, to name a few of the instruments. Add in the different forms of data that these instruments might collect, and it can be overwhelming: ADF, BF, BSE, CBED, CL, DF, EBIC, EBSD/BEKP/BKD/EBSP, ECCI, EDS/EDX, EELS, HAADF, NBD, SAD, and SE. For the brave reader, check out the acronym listing at the beginning of DB Williams and CB Carter's series on TEM.
Distinct iron isotopic signatures and supply from marine sediment dissolution
Authors: Homoky William B. , John Seth G. , Conway Tim M. , Mills Rachel A.
Published: July 2013

Oceanic iron inputs must be traced and quantified to learn how they affect primary productivity and climate. Chemical reduction of iron in continental margin sediments provides a substantial dissolved flux to the oceans, which is isotopically lighter than the crust, and so may be distinguished in seawater from other sources, such as wind-blown dust. However, heavy iron isotopes measured in seawater have recently led to the proposition of another source of dissolved iron from ‘non-reductive’ dissolution of continental margins. Here we present the first pore water iron isotope data from a passive-tectonic and semi-arid ocean margin (South Africa), which reveals a smaller and isotopically heavier flux of dissolved iron to seawater than active-tectonic and dysoxic continental margins. These data provide in situ evidence of non-reductive iron dissolution from a continental margin, and further show that geological and hydro-climatic factors may affect the amount and isotopic composition of iron entering the ocean.
Nanocontainers made of Various Materials with Tunable Shape and Size
Authors: Zhao Xianglong , Meng Guowen , Han Fangming , Li Xiangdong , Chen Bensong , Xu Qiaoling , Zhu Xiaoguang , Chu Zhaoqin , Kong Mingguang , Huang Qing
Published: July 2013

Nanocontainers have great potentials in targeted drug delivery and nanospace-confined reactions. However, the previous synthetic approaches exhibited limited control over the morphology, size and materials of the nanocontainers, which are crucial in practical applications. Here, we present a synthetic approach to multi-segment linear-shaped nanopores with pre-designed morphologies inside anodic aluminium oxide (AAO), by tailoring the anodizing duration after a rational increase of the applied anodizing voltage and the number of voltage increase during Al foil anodization. Then, we achieve nanocontainers with designed morphologies, such as nanofunnels, nanobottles, nano-separating-funnels and nanodroppers, with tunable sizes and diverse materials of carbon, silicon, germanium, hafnium oxide, silica and nickel/carbon magnetic composite, by depositing a thin layer of materials on the inner walls of the pre-designed AAO nanopores. The strategy has far-reaching implications in the designing and large-scale fabrication of nanocontainers, opening up new opportunities in nanotechnology applications.
Acinetobacter phage genome is similar to Sphinx 2.36, the circular DNA copurified with TSE infected particles
Authors: Longkumer Toshisangba , Kamireddy Swetha , Muthyala Venkateswar Reddy , Akbarpasha Shaikh , Pitchika Gopi Krishna , Kodetham Gopinath , Ayaluru Murali , Siddavattam Dayananda
Published: July 2013

While analyzing plasmids of Acinetobacter sp. DS002 we have detected a circular DNA molecule pTS236, which upon further investigation is identified as the genome of a phage. The phage genome has shown sequence similarity to the recently discovered Sphinx 2.36 DNA sequence co-purified with the Transmissible Spongiform Encephalopathy (TSE) particles isolated from infected brain samples collected from diverse geographical regions. As in Sphinx 2.36, the phage genome also codes for three proteins. One of them codes for RepA and is shown to be involved in replication of pTS236 through rolling circle (RC) mode. The other two translationally coupled ORFs, orf106 and orf96, code for coat proteins of the phage. Although an orf96 homologue was not previously reported in Sphinx 2.36, a closer examination of DNA sequence of Sphinx 2.36 revealed its presence downstream of orf106 homologue. TEM images and infection assays revealed existence of phage AbDs1 in Acinetobacter sp. DS002.
General Introduction to the Field of Environmental Catalysis: Green Catalysis with Supported Gold and Gold Bimetallic Nanoparticles
Authors: Dimitratos Nikolaos , Kiely Christopher J. , Hutchings Graham J.
Published: July 2013

A general introduction to environmental catalysis using supported gold and gold bimetallic alloy nanoparticles is presented. The general concepts of environmental catalysts are discussed and then two examples are described in more detail. The possibility of using sustainable feedstocks for the generation of chemicals is also considered. The modern chemical industry has been built up on processes that utilise key platform chemicals, e.g. ethene, propene, benzene and xylenes. These are readily derived from oil. Alternatively, natural gas can be steam reformed to give synthesis gas which provides an additional route to alcohols and hydrocarbons. While it is feasible that biomass can be converted to syngas and hence to existing key platform chemicals, this loses all of the chemical complexity that is inherent to bio‐derived molecules. However, bio‐derived sustainable feedstocks contain excessive levels of oxygen, and de‐oxygenation and dehydration reactions are required. In this chapter the general field is introduced and, in particular, the oxidation of glycerol using supported gold and gold bimetallic nanoparticles is described. In addition the use of solvent‐free reaction conditions is also discussed.
Synthesis and Physicochemical Properties of Gold‐based Catalysts
Authors: Louis Catherine
Published: July 2013

This chapter focuses on the chemical methods that are used for the preparation of gold‐based catalysts with the aim of forming small metal particles (<5 nm) stabilised on solid supports. The chapter mainly gathers the advances in gold catalyst preparation made since 2006, i.e. since the publication of the very first book on Catalysis by Gold (G. C. Bond, C. Louis and D. Thompson, Catalysis by Gold, Imperial College Press, London, 2006, vol. 6). Emphasis is given to the most frequently used preparation methods and to their new development, the new preparation methods, new supports and the recent development of gold‐based bimetallic catalysts.
Gold Catalysis for Hydrogenation Reactions
Authors: Corma Avelino , Sabater María J.
Published: July 2013

Gold has been shown to have potential advantages as a catalyst in a wide variety of chemical reactions, and hydrogenation is positioned as one important catalytic application of this metal. Indeed, hydrogenation is an important reaction in many areas of the chemical and petrochemical industries, where a continuous effort in searching for new catalysts and/or materials that efficiently adsorb and dissociate hydrogen is ever present.

Owing to the importance of the element, this chapter will cover essential aspects regarding the physico‐chemical properties of gold, its interactions with hydrogen, reactivity for the hydrogen H–D exchange, and in general, for selective hydrogenation reactions.

When appropriate, the chemical composition as well as the preparation of the catalyst will be specifically highlighted, because the catalytic activity appears to depend strongly on the method of synthesis of the catalyst, the nature of the support, the size of the gold particles and the thermal story of the catalyst.
Dual‐band filter using asymmetrical stub‐loaded resonator with independently controllable frequencies and bandwidths
Authors: Chu Qing‐Xin , Li Zhi‐Hui
Published: July 2013

A new kind of asymmetrical stub‐loaded resonator is proposed and applied to design a dual‐band bandpass filter (BPF) with independently controllable frequencies and bandwidths. The asymmetrical stub‐loaded resonator presented in this study has more superior performance than the conventional symmetrical stub‐loaded resonator. By appropriately selecting the lengths of the loaded stubs of the resonator, the first two resonant frequencies can be tuned independently without having influence on each other. The bandwidth of each passband of the proposed dual‐band filter using asymmetrical stub‐loaded resonators can be controlled independently by adjusting the coupling parameters. To validate the concept, one microstrip dual‐band BPF centred at 2.4 GHz/5.2 GHz is designed, fabricated and measured. It is found that the simulated and measured results are in good agreement.
Microwave phase perturbation and ionisation measurement in vegetation fire plasma
Authors: Letsholathebe Douglas , Mphale Kgakgamatso
Published: July 2013

Interaction of low temperature high collisional combustion plasma with electromagnetic wave energy results in a phase lag of the incident wave. If normalised collision frequency {(φeff)/2πf0} is much greater than unity (1), the phase shift (Δφ) varies linearly with plasma frequency, and hence with ionisation in plasma. Ionisation in vegetation fires (highly collisional atmospheric pressure plasma) has implications on the safety of fire‐fighters. During wildfire suppression, radio communication blackout at very/ultra high frequency has been experienced. A cylindrical fire burner was constructed in which various natural vegetation materials could be used as fuel. The burner was equipped with Type K thermocouples to measure fuel combustion temperature and was used as cavity for microwaves with laboratory quality network analyser to measure phase shift. In the experiment, microwaves were caused to propagate combustion zones of eucalyptus litter fires with maximum temperatures of 1142 and 1174 K, respectively. The measured phase shift ranged from 7.34 to 11.63°. Calculated ionisation from the phase shift measurements were from 1.9 to 2.0 × 1016 m− 3.
Design of a dual‐polarised wideband short backfire antenna with high gain
Authors: Juan Lei , Guang Fu , Lin Yang
Published: July 2013

The short backfire antenna (SBA) has been widely used for mobile satellite communications, tracking, telemetry and wireless local‐area network applications. A dual‐polarised wideband SBA excited by a hybrid configuration of waveguide and ortho‐mode transducer is described here. The bandwidth widening of the antenna is achieved by the appearance of the second resonance point, owing to the parasitic reflector suspended on the conical sub‐reflector. The aperture radiation efficiency is improved according to the reshaping of primary and sub‐reflector, as well as the choke device added to the primary reflector. The antenna is designed to operate within the L‐band. It has a frequency bandwidth for voltage standing wave ratio ≤ 1.5 of about 8% and a maximum gain of 20 dB. Within the antenna bandwidth, the gain and the radiation efficiency have values more than 19.5 dB and 76%, respectively. The designed antenna has a simple and compact construction and high mechanical and electrical characteristics; hence, it is appropriate for the satellite communication application. The operating mechanism is investigated to explain why the SBA can obtain good impedance and radiation characteristics. A parametric study is conducted for the use of practical engineering design.
Reduced and conventional size multi‐band circular patch antennas loaded with metamaterials
Authors: Ferdous Saimoom , Hossain Ababil , Chowdhury Shah Mahmud Hasan , Mahdy Mahdy Rahman Chowdhury , Abdul Matin
Published: July 2013

In this study, a novel technique to achieve multi‐band performance for both reduced and conventional size circular microstrip patch antennas loaded with metamaterial has been proposed. Incorporation of symmetric slotting concept with the concept of additional mode modification for both MNG (µ negative) and ENG (ɛ negative) metamaterial loaded circular patch antennas have been shown. The use of metamaterial creates an unconventional mode, whereas symmetrical slotting not only modifies another band but also improves the gain by around 1 dB of unconventional mode for MNG loaded antenna. Design algorithms for metamaterial loaded circular patch antennas have been developed to achieve size reduction and highly directive multiband property. Based on these design algorithms, at first a reduced size triple band circular patch antenna loaded with MNG metamaterial has been shown where around 35% size reduction is achievable. Later, a triple band conventional size circular patch antenna partially loaded with ENG metamaterial has been designed with high gain and directive performances for all three bands compared to previously reported such antennas.
Direction‐of‐arrival estimation for uncorrelated and coherent signals in the presence of multipath propagation
Authors: Gan Lu , Luo Xiaoyu
Published: July 2013

The authors propose a novel direction‐of‐arrival (DOA) estimation method for signals that are uncorrelated, partially coherent or fully coherent in the presence of multipath propagation. First, uncorrelated and coherent signals are distinguished by the rotational invariance techniques as well as the property of the moduli of eigenvalues. The DOAs of the uncorrelated signals are then estimated based on their related eigenvalues. Finally, the singular value decomposition of virtual steering vectors is used to estimate the DOAs of the coherent signals while avoiding the cross‐term effects. The effectiveness and efficiency of the proposed method are demonstrated by the simulation results.
Dual‐band coplanar waveguide‐fed smiling monopole antenna for WiFi and 4G long‐term evolution applications
Authors: de Cos María Elena , Mantash Mohamad , Tarot Anne‐Claude , Las‐Heras Fernando
Published: July 2013

A novel ‘coplanar waveguide’‐fed planar monopole antenna with dual‐band operation for WiFi and ‘long‐term evolution 4G (LTE)’ applications is presented. The simple antenna's geometry is composed of a circular radiating patch with a smiling slot, and it occupies a small size of 41.6(L) × 28.38(W) × 1.52(h) mm3. Two operating bands covering 2.3–3.0 and 4.7–5.9 GHz are achieved by carefully optimising the position and size of a smiling slot. An antenna prototype has been manufactured and it has been characterised in terms of return loss and radiation pattern measurements in anechoic chamber exhibiting almost omnidirectional patterns and appreciable gain across the operating bands, being suitable for WiFi and 4G LTE applications.
Electromagnetic band‐gap based corrugated structures for reducing mutual coupling of compact 60 GHz cavity‐backed antenna arrays in low temperature co‐fired ceramics
Authors: Lu Yi‐Fong , Lin Yi‐Cheng
Published: July 2013

Reducing the mutual coupling of antenna elements in 60 GHz phased arrays is an important issue because it directly affects the input impedance matching and radiation performances. This study presents an electromagnetic band‐gap (EBG) based design using corrugated structures to reduce the mutual coupling between two closely placed antenna elements. An isolation enhancement of 3.6 to 10.3 dB was achieved from the proposed EBG‐based corrugated structure over the unlicensed band of 57 to 66 GHz. Based on the available thickness of low temperature co‐fired ceramics (LTCC) layered process, the authors built a prototype with a corrugation height of 0.7 mm and measured the port isolation and radiation performances. The experimental results show that using the corrugated design may reduce the mutual coupling by 2.1 to 4.4 dB compared with that without corrugation. In addition, the corrugated design under the thickness restriction of the LTCC process is discussed in this study. An alternative structure with an extended corrugation height is included, where the port isolation is improved by more than 3 dB over the entire band of 57 to 66 GHz.
Zigzag metallic conductors as frequency selective surfaces
Authors: Delihacioglu Kemal , Sabah Cumali , Karaaslan Muharrem , Ünal Emin
Published: July 2013

Reflection and transmission properties of a new type of frequency selective surface (FSS) made of zigzag metallic elements placed periodically on a dielectric substrate are investigated theoretically for arbitrary polarisation. The electric field integral equation technique with the subdomain overlapping piecewise sinusoidal basis functions are employed to compute the unknown current coefficients induced on the metallic elements. The zigzag FSS arrays act as a low‐pass filter in S‐(1–5 GHz), X‐(8–12 GHz) and Ku‐(12–18 GHz) bands. Owing to multiple resonances the zigzag FSS arrays can be used in multiband frequency applications. Between the resonances there exist transmission windows that allow full energy transfer. By removing the first and third arms, the power reflection coefficient of three‐arm zigzag FSS is compared with a freestanding strip FSS, and it is compatible with the measured and calculated results found in the literature.
Facile hydrothermal synthesis of ultra‐long manganese oxyhydroxide nanorods and their transformation into MnO2 and Mn2O3 nanorods
Authors: Li Zhong Chun , Chen Si Si , Dong Chao , Chen Xu Hong , Zhou Quan Fa
Published: July 2013

Single‐crystal manganese oxyhydroxide (MnOOH) nanorods with high aspect ratios have been successfully prepared employing a simple hydrothermal route based on the redox between potassium permanganate (KMnO4) and polyvinyl pyrrolidone (PVP). By adjusting the reaction temperature, reaction time and the mass ratio of PVP/KMnO4, MnOOH nanorods with lengths up to 20 μm and diameters in the range of 100–400 nm could be facilely prepared in high yield. The as‐prepared MnOOH nanorods were characterised by X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, high‐resolution transmission electron microscopy and Fourier transformed infrared spectroscopy. The formation mechanism of MnOOH nanorods was preliminarily discussed based on the Ostwald's ripening process. Furthermore, MnO2 and Mn2O3 nanorods with high aspect ratios were synthesised by calcination of MnOOH nanorods.
Fabrication of a substrate for Ag‐nanorod metal‐enhanced fluorescence using the oblique angle deposition process
Authors: Ju Jonghyun , Byeon Euihyeon , Han Yun‐ah , Kim Seok‐min
Published: July 2013

Metal‐enhanced fluorescence (MEF) is a powerful technology to improve the sensitivity of fluorescence analysis by allowing fluorophores to interact with enhanced electromagnetic fields generated by the localised surface plasmon resonance effects of metallic nanostructures. To apply MEF technology to disposable DNA or protein microarray analysis, metallic nanostructures need to be fabricated on the full area of a glass slide at low cost. In this reported work an oblique angle deposition process was used to fabricate Ag nanorods on the whole area of a 25 × 75 mm2 glass slide to serve as an inexpensive and large‐area MEF substrate. To examine the feasibility of the proposed substrate and maximise signal enhancement, Ag nanorods with different lengths were deposited on glass slides. Different concentrations of streptavidin‐conjugated Cy5 in phosphate buffered saline were spotted onto the Ag nanorods and bare glass substrates, and the fluorescence signals were measured and compared. Longer Ag nanorods improved the fluorescence enhancement factor because of a higher surface plasmon resonance effect and the large surface area of the nanostructure with a high aspect ratio. A maximum enhancement factor of −23 was obtained from Ag nanorods that were 1000 nm long with comparable uniformity with the glass substrate.
The wobbling-to-swimming transition of rotated helices
Authors: Man Yi , Lauga Eric
Published: July 2013

A growing body of work aims at designing and testing micron-scale synthetic swimmers. One method, inspired by the locomotion of flagellated bacteria, consists of applying a rotating magnetic field to a rigid, helically shaped, propeller attached to a magnetic head. When the resulting device, termed an artificial bacteria flagellum, is aligned perpendicularly to the applied field, the helix rotates and the swimmer moves forward. Experimental investigation of artificial bacteria flagella shows that at low frequency of the applied field, the axis of the helix does not align perpendicularly to the field but wobbles around the helix, with an angle decreasing as the inverse of the field frequency. Using numerical computations and asymptotic analysis, we provide a theoretical explanation for this wobbling behavior. We numerically demonstrate the wobbling-to-swimming transition as a function of the helix geometry and the dimensionless Mason number which quantifies the ratio of viscous to magnetic torques. We then employ an asymptotic expansion for near-straight helices to derive an analytical estimate for the wobbling angle allowing to rationalize our computations and past experimental results. These results can help guide future design of artificial helical swimmers.
Stimulated and spontaneous four-wave mixing in silicon-on-insulator coupled photonic wire nano-cavities
Authors: Azzini Stefano , Grassani Davide , Galli Matteo , Gerace Dario , Patrini Maddalena , Liscidini Marco , Velha Philippe , Bajoni Daniele
Published: July 2013

We report on four-wave mixing in coupled photonic crystal nano-cavities on a silicon-on-insulator platform. Three photonic wire cavities are side-coupled to obtain three modes equally separated in energy. The structure is designed to be self-filtering, and we show that the pump is rejected by almost two orders of magnitude. We study both the stimulated and the spontaneous four-wave mixing processes: owing to the small modal volume, we find that signal and idler photons are generated with a hundred-fold increase in efficiency as compared to silicon micro-ring resonators.
Linear stability analysis of Korteweg stresses effect on miscible viscous fingering in porous media
Authors: Pramanik Satyajit , Mishra Manoranjan
Published: July 2013

Viscous fingering (VF) is an interfacial hydrodynamic instability phenomenon observed when a fluid of lower viscosity displaces a higher viscous one in a porous media. In miscible viscous fingering, the concentration gradient of the undergoing fluids is an important factor, as the viscosity of the fluids are driven by concentration. Diffusion takes place when two miscible fluids are brought in contact with each other. However, if the diffusion rate is slow enough, the concentration gradient of the two fluids remains very large during some time. Such steep concentration gradient, which mimics a surface tension type force, called the effective interfacial tension, appears in various cases such as aqua-organic, polymer-monomer miscible systems, etc. Such interfacial tension effects on miscible VF is modeled using a stress term called Korteweg stress in the Darcy's equation by coupling with the convection-diffusion equation of the concentration. The effect of the Korteweg stresses at the onset of the instability has been analyzed through a linear stability analysis using a self-similar Quasi-steady-state-approximation (SS-QSSA) in which a self-similar diffusive base state profile is considered. The quasi-steady-state analyses available in literature are compared with the present SS-QSSA method and found that the latter captures appropriately the unconditional stability criterion at an earlier diffusive time as well as in long wave approximation. The effects of various governing parameters such as log-mobility ratio, Korteweg parameters, disturbances' wave number, etc., on the onset of the instability are discussed for, (i) the two semi-infinite miscible fluid zones and (ii) VF of the miscible slice cases. The stabilizing property of the Korteweg stresses effect is observed for both of the above mentioned cases. Critical miscible slice lengths are computed to have the onset of the instability for different governing parameters with or without Korteweg stresses. These stabilizing properties of the Korteweg stresses captured in this present study are in agreement with the numerical simulations of fully nonlinear problem and the experimental observations reported in the literature.