Port decoupling for small arrays by means of an eigenmode feed network

An alternative approach to port decoupling and matching of arrays with tightly coupled elements is proposed. The method is based on the inherent decoupling effect obtained by feeding the orthogonal eigenmodes of the array. For this purpose, a modal feed network is connected to the array. The decoupled external ports of the feed network may then be matched independently by using conventional matching circuits. Such a system may be used in digital beam forming applications with good signal-to-noise performance. The theory is applicable to arrays with an arbitrary number of elements, but implementation is only practical for smaller arrays. The principle is illustrated by means of two examples.

New modal feed network for a compact monopole array with isolated ports

An element spacing of less than half a wavelength introduces strong mutual coupling between the ports of compact antenna arrays. The strong coupling causes significant system performance degradation. A decoupling network may compensate for the mutual coupling. Alternatively, port decoupling can be achieved using a modal feed network. In response to an input signal at one of the input ports, this feed network excites the antenna elements in accordance with one of the eigenvectors of the array scattering parameter matrix. In this paper, a novel 4-element monopole array is described. The feed network of the array is implemented as a planar ring-type circuit in stripline with four coupled line sections. The new configuration offers a significant reduction in size, resulting in a very compact array.

Apparent digestibility of selected feed ingredients in diets formulated for the sub-adult mud crab, Scylla paramamosain, in Vietnam

The present study was conducted to explore the potential to incorporate local plant-based feed ingredients into diets formulated for the mud crab species, Scylla paramamosain, commonly exploited for aquaculture in South-east Asia. Four test ingredients (defatted soybean meal, rice bran, cassava meal and corn flour) were incorporated at 30% or 45% inclusion levels in a fishmeal-based reference diet and used in digestibility trials where apparent digestibility coefficients (ADCs) for experimental diets and test ingredients were determined. Generally, high ADC values were obtained using diets containing 30% soybean meal or rice bran. By contrast, the lowest ADC values were obtained for the diet containing 45% cassava meal [70.9% for dry matter (ADMD); 77.1% for crude protein (ACPD) and 80.2% for gross energy (AGED)]. Similar trends were observed when ADC ingredient (I) digestibilities were compared. Specifically, the highest ADCI values were obtained for soybean meal when used at a 30% inclusion level (87.6% ADMDI; 98.4% ACPDI and 95.6% AGEDI) while the lowest ADCI values were obtained using cassava meal at a 45% inclusion level (53.8% ADMDI; 60.2% ACPDI and 67.3% AGEDI). Based on the current findings, we propose that soybean meal and rice bran could be considered for incorporation into formulated diets for S. paramamosain.

Effect of selected feed meals and starches on diet digestibility in the mud crab, Scylla serrata

The present study examined the capacity of the mud crab, Scylla serrata to digest experimental diets that contained different animal and plant-based feed meals or different levels or types of starch. The apparent dry matter digestibility (ADMD) coefficients for all feed meals tested in the first part of this study, except meat meal, were similar (78–88%). Crude protein digestibility (ACPD) coefficients for all feed meals were relatively high, with values ranging from 86% to 96%. Cotton seed meal, poultry meal, canola meal, fishmeal, soybean meal and lupin meal had similar gross energy digestibility (AGED) values (P>0.05) ranging from 84% to 89%. In the second part of this study, the impact of selected starches on the digestibility of fishmeal-based formulated diets was assessed. The apparent starch digestibility (ASD) of wheat starch decreased significantly as the inclusion level was increased from 15% to 60%, however, there was no significant effect on ACPD values. At a 30% inclusion level, the ASD of diets containing different starches decreased in the order corn>wheat>potato=rice. Moreover, ACPD values were significantly higher (P<0.05) in the diets containing corn or rice starch than in those containing wheat or potato starches.

Library and information science education 2.0 : guiding principles and models of best practice. Interview with Lyn Hay.

In 2005, Stephen Abram, vice president of Innovation at SirsiDynix, challenged library and information science (LIS) professionals to start becoming “librarian 2.0.” In the last few years, discussion and debate about the “core competencies” needed by librarian 2.0 have appeared in the “biblioblogosphere” (blogs written by LIS professionals). However, beyond these informal blog discussions few systematic and empirically based studies have taken place. A project funded by the Australian Learning and Teaching Council fills this gap. The project identifies the key skills, knowledge, and attributes required by “librarian 2.0.” Eighty-one members of the Australian LIS profession participated in a series of focus groups. Eight themes emerged as being critical to “librarian 2.0”: technology, communication, teamwork, user focus, business savvy, evidence based practice, learning and education, and personal traits. Guided by these findings interviews with 36 LIS educators explored the current approaches used within contemporary LIS education to prepare graduates to become “librarian 2.0”. This video presents an example of ‘great practice’ in current LIS education as it strives to foster web 2.0 professionals.

Microstrip to parallel strip balun as spiral antenna feed

This paper presents the design and implementation of a microstrip to parallel strip balun which are frequently used as balanced antennas feed. This wideband balun transition is composed of a parallel strip which is connected to the spiral antenna and a microstrip line where the width of the ground plane is gradually reduced to eventually resemble the parallel strip. The taper accomplishes the mode and impedance transformation. This balun has significantly improved bandwidth characteristics. The entire circuit was fabricated on RT Duriod 5880 substrate. The circuit designs were simulated and optimised using CST Microwave Studio and the simulated results are compared with the measured results. The back-to-back microstrip to parallel strip has a return loss of better than 10 dB over a wide bandwidth from 1.75 to 15 GHz. The performance of the proposed balun was validated with the spiral antenna. The measured results were compared with the simulated results and it shows that the antenna operates well in wideband frequency range from 2.5 to 15 GHz.

Enhancing opportunities to feed forward ; developing problem solving skills using web based scenarios

Universities often struggle to satisfy students’ need for feedback. This is an area where student satisfaction with courses of study can be low. Yet it is clear that one of the properties of good teaching is giving the highest quality feedback on student work. The term ‘feedback’ though is most commonly associated with summative assessment given by a teacher after work is completed. The student can often be a passive participant in the process. This paper looks at the implementation of a web based interactive scenario completed by students prior to summative assessment. It requires students to participate actively to develop and improve their legal problem solving skills. Traditional delivery of legal education focuses on print and an instructor who conveys the meaning of the written word to students. Today, mixed modes of teaching are often preferred and they can provide enhanced opportunities for feeding forward with greater emphasis on what students do. Web based activities allow for flexible delivery; they are accessible off campus, at a time that suits the student and may be completed by students at their own pace. This paper reports on an online interactive activity which provides valuable formative feedback necessary to allow for successful completion of a final problem solving assignment. It focuses on how the online activity feeds forward and contributes to the development of legal problem solving skills. Introduction to Law is a unit designed and introduced for completion by undergraduate students from faculties other than law but is focused most particularly on students enrolled in the Bachelor of Entertainment Industries degree, a joint initiative of the faculties of Creative Industries, Business and Law at the Queensland University of Technology in Australia. The final (and major) assessment for the unit is an assignment requiring students to explain the legal consequences of particular scenarios. A number of cost effective web based interactive scenarios have been developed to support the unit’s classroom activities. The tool commences with instruction on problem solving method. Students then view the stimulus which is a narrative produced in the form of a music video clip. A series of questions are posed which guide students through the process and they can compare their responses with sample answers provided. The activity clarifies the problem solving method and expectations for the summative assessment and allows students to practise the skill. The paper reports on the approach to teaching and learning taken in the unit including the design process and implementation of the activity. It includes an evaluation of the activity with respect to its effectiveness as a tool to feed forward and reflects on the implications for the teaching of law in higher education.

Adaption of horses to a novel dynamic feeding system : movement and behavioural responses

Reasons for performing study: Many domestic horses and ponies are sedentary and obese due to confinement to small paddocks and stables and a diet of infrequent, high-energy rations. Severe health consequences can be associated with this altered lifestyle. Objectives: The aims of this study were to investigate the ability of horses to learn to use a dynamic feeder system and determine the movement and behavioural responses of horses to the novel system. Methods: A dynamic feed station was developed to encourage horses to exercise in order to access ad libitum hay. Five pairs of horses (n = 10) were studied using a randomised crossover design with each pair studied in a control paddock containing a standard hay feeder and an experimental paddock containing the novel hay feeder. Horse movement was monitored by a global positioning system (GPS) and horses observed and their ability to learn to use the system and the behavioural responses to its use assessed. Results: With initial human intervention all horses used the novel feeder within 1 h. Some aggressive behaviour was observed between horses not well matched in dominance behaviour. The median distance walked by the horses was less (P = 0.002) during a 4 h period (117 [57–185] m) in the control paddock than in the experimental paddock (630 [509–719] m). Conclusions: The use of an automated feeding system promotes increased activity levels in horses housed in small paddocks, compared with a stationary feeder.

A comparative study on pyrolysis for liquid oil from different biomass solid wastes

Locally available different bbiomass solid wastes, pine seed, date seed, plum seed, nutshell, hay of catkin, rice husk, jute stick, saw-dust, wheat straw and linseed residue in the particle form have been pyrolyzed in laboratory scale fixed bed reactor. The products obtained are pyrolysis oil, solid char and gas. The oil and char are collected while the gas is flared into atmosphere. The variation of oil yield for different biomass feedstock with reaction parameters like, reactor bed temperature, feed size and running time is presented in a comparative way in the paper. A maximum liquid yield of 55 wt% of dry feedstock is obtained at an optimum temperature of 500 °C for a feed size of 300-600 μm with a running time of 55 min with nutshell as the feedstock while the minimum liquid yield is found to be 30 wt% of feedstock at an optimum temperature of 400 °C for a feed size of 2.36 mm with a running time of 65 min for linseed residue. A detailed study on the variation of product yields with reaction parameters is presented for the latest investigation with pine seed as the feedstock where a maximum liquid yield of 40 wt% of dry feedstock is obtained at an optimum temperature of 500 °C for a feed size of 2.36-2.76 mm with a running time of 120 min. The characterization of the pyrolysis oil is carried out and a comparison of some selected properties of the oil is presented. From the study it is exhibited that the biomass solid wastes have the potential to be converted into liquid oil as a source of renewable energy with some further upgrading of the products.

"Ruby's Music Festival" : developing problem solving skills using online scenarios and creating opportunities to feed forward

One of the characteristics of good teaching is giving the highest quality feedback on student work but the term “feedback” is most commonly associated with summative assessment given by a teacher after work is completed. The student can often be a passive participant in the process. This article looks at the implementation of web based scenarios completed by students prior to summative assessment with the objective of improving legal problem solving skills. It examines the design process and the implementation of the problem solving activity and the approach to teaching and learning taken in the new law unit of which it is part. We argue that such activities are effective tools to feed forward and reflect on the implications for the effective teaching of law in higher education.

Improvements to bauxite residue neutralisation efficiency through the use of alternative feed sources

Currently, open circuit Bayer refineries pump seawater directly into their operations to neutralise the caustic fraction of the Bayer residue. The resulting supernatant has a reduced pH and is pumped back to the marine environment. This investigation has assessed modified seawater sources generated from different ion filtration processes to compare their relative capacities to neutralise bauxite residues. An assessment of the chemical stability of the neutralisation products, neutralisation efficiency, discharge water quality, bauxite residue composition, and associated economic benefits have been considered to determine the most preferable seawater filtration process based on implementation costs, savings to operations and environmental benefits. The mechanism of neutralisation for each technology was determined to be predominately due to the formation of Bayer hydrotalcite and calcium carbonate, however variations in neutralisation capacity and efficiencies have been observed. The neutralisation efficiency of each feed source has been found to be dependent on the concentration of magnesium, aluminium, calcium and carbonate. These studies have revealed that multiple neutralisation steps occur throughout the process. Environmental, economic and social advantages and disadvantages of the different filtration technologies have been explored to determine the most sustainable method for the neutralisation of bauxite residues. The relative degree of “green” associated with nanofiltered seawater and reverse osmosis filtered seawater are discussed.

Will the TPP feed consumers to the wolves of Wall Street?

In the wake of the global financial crisis, there’s been a push by policy-makers for greater regulation of banks, financial institutions and the “wolves of Wall Street”. This was accompanied by a highly visible Occupy Wall Street movement, demanding political and legal reform. But could new trade agreements undermine consumer protection?

Don't feed the 'patent trolls': [An overhaul of the patent system is necessary to keep up with advances in technology.]

The government is sitting on its hands when an overhaul of the patent system is necessary to keep up with advances in technology in the 21st century.

Genome-wide association analysis identifies 11 risk variants associated with the asthma with hay fever phenotype

Background To date, no genome-wide association study (GWAS) has considered the combined phenotype of asthma with hay fever. Previous analyses of family data from the Tasmanian Longitudinal Health Study provide evidence that this phenotype has a stronger genetic cause than asthma without hay fever. Objective We sought to perform a GWAS of asthma with hay fever to identify variants associated with having both diseases. Methods We performed a meta-analysis of GWASs comparing persons with both physician-diagnosed asthma and hay fever (n = 6,685) with persons with neither disease (n = 14,091). Results At genome-wide significance, we identified 11 independent variants associated with the risk of having asthma with hay fever, including 2 associations reaching this level of significance with allergic disease for the first time: ZBTB10 (rs7009110; odds ratio [OR], 1.14; P = 4 × 10−9) and CLEC16A (rs62026376; OR, 1.17; P = 1 × 10−8). The rs62026376:C allele associated with increased asthma with hay fever risk has been found to be associated also with decreased expression of the nearby DEXI gene in monocytes. The 11 variants were associated with the risk of asthma and hay fever separately, but the estimated associations with the individual phenotypes were weaker than with the combined asthma with hay fever phenotype. A variant near LRRC32 was a stronger risk factor for hay fever than for asthma, whereas the reverse was observed for variants in/near GSDMA and TSLP. Single nucleotide polymorphisms with suggestive evidence for association with asthma with hay fever risk included rs41295115 near IL2RA (OR, 1.28; P = 5 × 10−7) and rs76043829 in TNS1 (OR, 1.23; P = 2 × 10−6). Conclusion By focusing on the combined phenotype of asthma with hay fever, variants associated with the risk of allergic disease can be identified with greater efficiency.

Hay fever: An underappreciated and chronic disease

Allergic rhinitis continues to be a significant chronic disease that affects younger, usually healthier people, with considerable impacts on school performance and work productivity. Symptom-directed treatment is usually sufficient but specific immunotherapy should be considered in severely affected patients.