Evaluating environmental enrichment options for commercial broiler chickens

Implications Provision of environmental enrichment in line with that required by welfare-based quality assurance schemesdoes not always appear to lead to clear improvements in broiler chicken welfare. This research perhaps serves to highlightthe deficit in information regarding the ‘real world’ implications of enrichment with perches, string and straw bales.

Introduction Earlier work showed that provision of natural light and straw bales improved leg health in commercial broilerchickens (Bailie et al., 2013). This research aimed to determine if additional welfare benefits were shown in windowedhouses by increasing straw bale provision (Study 1), or by providing perches and string in addition to straw bales (Study 2).

Material and methods Commercial windowed houses in Northern Ireland containing ~23,000 broiler chickens (placed inhouses as hatched) were used in this research which took place in 2011. In Study 1 two houses on a single farm wereassigned to one of two treatments: (1) 30 straw bales per house (1 bale/44m2), or (2) 45 straw bales per house (1bale/29m2). Bales of wheat straw, each measuring 80cm x 40cm x 40cm were provided from day 10 of the rearing cycle,as in Bailie et al. (2013). Treatments were replicated over 6 production cycles (using 276,000 Ross 308 and Cobb birds),and were swapped between houses in each replicate. In Study 2, four houses on a single farm were assigned to 1 of 4treatments in a 2 x 2 factorial design. Treatments involved 2 levels of access to perches (present (24/house), or absent), and2 levels of access to string (present (24/house), or absent), and both types of enrichment were provided from the start of thecycle. Each perch consisted of a horizontal, wooden beam (300 cm x 5 cm x 5cm) with a rounded upper edge resting on 2supports (15 cm high). In the string treatment, 6 pieces of white nylon string (60 cm x 10 mm) were tied at their mid-pointto the wire above each of 4 feeder lines. Thirty straw bales were also provided per house from day 10. This study wasreplicated over 4 production cycles using 368,000 Ross 308 birds. In both studies behaviour was observed between 0900and 1800 hours in weeks 3-5 of the cycle. In Study 1, 8 focal birds were selected in each house each week, and generalactivity, exploratory and social behaviours recorded directly for 10 minutes. In Study 2, 10 minute video recordings weremade of 6 different areas (that did not contain enrichment) of each house each week. The percentage of birds engaged inlocomotion or standing was determined through scan sampling these recordings at 120 second intervals. Four perches andfour pieces of string were filmed for 25 mins in each house that contained these enrichments on one day per week. The totalnumber of times the perch or string was used was recorded, along with the duration of each bout. In both studies, gaitscores (0 (perfect) to 5 (unable to walk)) and latency to lie (measured in seconds from when a bird had been encouraged tostand) were recorded in 25 birds in each house each week. Farm and abattoir records were also used in both studies todetermine the number of birds culled for leg and other problems, mortality levels, slaughter weights, and levels of pododermatitis and hock burn. Data were analysed using SPSS (version 20.0) and treatment and age effects on behaviouralparameters were determined in normally distributed data using ANOVA (‘Straw bale density*week’, or‘string*perches*week’ as appropriate), and in non-normally distributed data using Kuskall-Wallace tests (P<0.05 forsignificance) . Treatment (but not age) effects on performance and health data were determined using the same testsdepending on normality of data.

Results Average slaughter weight, and levels of mortality, culling, hock burn and pododermatitis were not affected bytreatment in either study (P<0.05). In Study 1 straw bale (SB) density had no significant effect on the frequency orduration of behaviours including standing, walking, ground pecking, dust bathing, pecking at bales or aggression, or onaverage gait score (P>0.05). However, the average latency to lie was greater when fewer SB were provided (30SB 23.38s,45SB 18.62s, P<0.01). In Study 2 there was an interaction between perches (Pe) and age in lying behaviour, with higherpercentages of birds observed lying in the Pe treatment during weeks 4 and 5 (week 3 +Pe 77.0 -Pe 80.9, week 4 +Pe 79.5 -Pe 75.2, week 5 +Pe 78.4 -Pe 76.2, P<0.02). There was also a significant interaction between string (S) and age inlocomotory behaviour, with higher percentages of birds observed in locomotion in the string treatment during week 3 butnot weeks 4 and 5 (week 3 +S 4.9 -S 3.9, week 4 +S 3.3 -S 3.7, week 5 +S 2.6 -S 2.8, P<0.04). There was also aninteraction between S and age in average gait scores, with lower gait scores in the string treatment in weeks 3 and 5 (week3: +S 0.7, -S 0.9, week 4: +S 1.5, -S 1.4, week 5: +S 1.9, -S 2.0, P<0.05). On average per 25 min observation there were15.1 (±13.6) bouts of perching and 19.2 (±14.08) bouts of string pecking, lasting 117.4 (±92.7) and 4.2 (±2.0) s for perchesand string, respectively.

Conclusion Increasing straw bale levels from 1 bale/44m2 to 1 bale/29m2 floor space does not appear to lead to significantimprovements in the welfare of broilers in windowed houses. The frequent use of perches and string suggests that thesestimuli have the potential to improve welfare. Provision of string also appeared to positively influence walking ability.However, this effect was numerically small, was only shown in certain weeks and was not reflected in the latency to lie.Further research on optimum design and level of provision of enrichment items for broiler chickens is warranted. Thisshould include measures of overall levels of activity (both in the vicinity of, and away from, enrichment items).

Accounting for clean, fast and high yielding reactions under microwave conditions

Thermal reactions proceed optimally when they are rapidly heated to the highest tolerable temperature, held there for the shortest possible time and then quenched. This is explained through assessments of reaction kinetics in literature examples and models. Although presently available microwave equipment is better suited to rapid heating than resistance-heated systems, the findings do not depend upon the method of heating. Claims that microwave heated reactions proceed faster and more cleanly than their conventionally heated counterparts are valid only when comparably rapid heating and cooling cannot be obtained by conventional heating. These findings suggest that rigid adherence to the sixth principle of green chemistry, relating to the use of ambient temperature and pressure, may not always afford optimal results. © 2010 The Royal Society of Chemistry.

An Evaluation of 1D Loss Model Collections for the Off-Design Performance Prediction of an Automotive Turbocharger Compressor

Abstract. Single-zone modelling is used to assess different collections of impeller 1D loss models. Three collections of loss models have been identified in literature, and the background to each of these collections is discussed. Each collection is evaluated using three modern automotive turbocharger style centrifugal compressors; comparisons of performance for each of the collections are made. An empirical data set taken from standard hot gas stand tests for each turbocharger is used as a baseline for comparison. Compressor range is predicted in this study; impeller diffusion ratio is shown to be a useful method of predicting compressor surge in 1D, and choke is predicted using basic compressible flow theory. The compressor designer can use this as a guide to identify the most compatible collection of losses for turbocharger compressor design applications. The analysis indicates the most appropriate collection for the design of automotive turbocharger centrifugal compressors.

Finite Element Analysis of the Enhanced Strength of Laterally Restrained RC Slabs

This paper presents the numerical simulation of the ultimate behaviour of 85 one-way and two-way spanning laterally restrained concrete slabs of variable thickness, span, reinforcement ratio, strength and boundary conditions reported in literature by different authors. The developed numerical model was described and all the assumptions were illustrated. ABAQUS, a Finite Element Analysis suite of software, was employed. Non-linear implicit static general analysis method offered by ABAQUS was used. Other analysis methods were also discussed in general in terms of application such as Explicit Dynamic Analysis and Riks method. The aim is to demonstrate the ability and efficacy of FEA to simulate the ultimate load behaviour of slabs considering different material properties and boundary conditions. The authors intended to present a numerical model that provides consistent predictions of the ultimate behaviour of laterally restrained slabs that could be used as an alternative for expensive real life testing as well as for the design and assessment of new and existing structures respectively. The enhanced strength of laterally-restrained slabs compared with conventional design methods predictions is believed to be due to compressive membrane action (CMA). CMA is an inherent phenomenon of laterally restrained concrete beams/slabs. The numerical predictions obtained from the developed model were in good correlation with the experimental results and with those obtained from the CMA method developed at the Queen’s University Belfast, UK.

Operators for Similarity Search: Semantics, Techniques and Usage Scenarios

This book provides a comprehensive tutorial on similarity operators. The authors systematically survey the set of similarity operators, primarily focusing on their semantics, while also touching upon mechanisms for processing them effectively.

The book starts off by providing introductory material on similarity search systems, highlighting the central role of similarity operators in such systems. This is followed by a systematic categorized overview of the variety of similarity operators that have been proposed in literature over the last two decades, including advanced operators such as RkNN, Reverse k-Ranks, Skyline k-Groups and K-N-Match. Since indexing is a core technology in the practical implementation of similarity operators, various indexing mechanisms are summarized. Finally, current research challenges are outlined, so as to enable interested readers to identify potential directions for future investigations.

In summary, this book offers a comprehensive overview of the field of similarity search operators, allowing readers to understand the area of similarity operators as it stands today, and in addition providing them with the background needed to understand recent novel approaches.

A novel TRNSYS type for short-term borehole heat exchanger simulation: B2G model

Models of ground source heat pump (GSHP) systems are used as an aid for the correct design and optimization of the system. For this purpose, it is necessary to develop models which correctly reproduce the dynamic thermal behavior of each component in a short-term basis. Since the borehole heat exchanger (BHE) is one of the main components, special attention should be paid to ensuring a good accuracy on the prediction of the short-term response of the boreholes. The BHE models found in literature which are suitable for short-term simulations usually present high computational costs. In this work, a novel TRNSYS type implementing a borehole-to-ground (B2G) model, developed for modeling the short-term dynamic performance of a BHE with low computational cost, is presented. The model has been validated against experimental data from a GSHP system located at Universitat Politècnica de València, Spain. Validation results show the ability of the model to reproduce the short-term behavior of the borehole, both for a step-test and under normal operating conditions.

Sustainable non-automotive vehicles: The simulation challenges

Simulation is a well-established and effective approach to the development of fuel-efficient and low-emissions vehicles in both on-highway and off-highway applications.

The simulation of on-highway automotive vehicles is widely reported in literature, whereas research relating to non-automotive and off-highway vehicles is relatively sparse. This review paper focuses on the challenges of simulating such vehicles and discusses the differences in the approach to drive cycle testing and experimental validation of vehicle simulations. In particular, an inner-city diesel-electric hybrid bus and an ICE (Internal Combustion Engine) powered forklift truck will be used as case studies.

Computer prediction of fuel consumption and emissions of automotive vehicles on standardised drive cycles is well-established and commercial software packages such as AVL CRUISE have been specifically developed for this purpose. The vehicles considered in this review paper present new challenges from both the simulation and drive-cycle testing perspectives. For example, in the case of the forklift truck, the drive cycles involve reversing elements, variable mass, lifting operations, and do not specify a precise velocity-time profile. In particular, the difficulties associated with the prediction of productivity, i.e. the maximum rate of completing a series of defined operations, are discussed. In the case of the hybrid bus, the standardised drive cycles are unrepresentative of real-life use and alternative approaches are required in the development of efficient and low-emission vehicles.

Two simulation approaches are reviewed: the adaptation of a standard automotive vehicle simulation package, and the development of bespoke models using packages such as MATLAB/Simulink.

Laser-fabricated PET-Ti Hybrid Joints for Medical Device Applications

Currently, micro-joining of plastic parts to metal parts in medical devices is achieved by using medical adhesives, For example, pacemakers, defibrillators and neurological stimulators are designed using silicone adhesive to seal the joint between the polyurethane connector module and the titanium can [1]. Nevertheless, the use of adhesive is problematic because it requires a long time to cure and has high tendency to produce leachable products which might be harmful to the human body. An alternative for directly joining plastics to metal without adhesive is therefore required. Laser transmission joining (LTJ) is growing in importance, and has the potential to gain the niche in micro-fabrication of plastics-metal hybrid joints for medical device applications. The possibility of directly joining plastics to metal by LTJ technique have been demonstrated by a number of studies in recent literature [2]. The widely-accepted understanding of LTJ between plastics and metal is that generation and rapid expansion of micro-bubbles at the plastics-metal interface exert high local pressure to press the melted plastics towards the metal surface features during the laser processing [2]. This subsequently creates the plastics-metal hybrid joint by the mechanisms of mechanical interlocking as well as chemical and physical bonds between the plastics and metal surfaces. Although the micro-bubbles can help promote the mechanical interlocking effect to increase the joint strength, the creation of bubble is a random and complex process depending on the complicated interactions between the laser intensity, thermal degradation properties of plastics, surface temperature and topographical features of metal. In an ideal situation, it is desirable to create the hybrid plastics-metal joint without bubbles. However, the mechanical performance of the hybrid plastics-metal joint without bubbles is still unknown, and systematic comparison between the hybrid joints with and without bubbles is lacking in literature. This becomes the objective of this study. In this work, the laser process parameters were carefully chosen from a preliminary study, such that different hybrid joints: with and without bubbles can be produced and compared. Biocompatible PET and commercially pure Ti were selected as materials for laser joining.