184 research outputs found
Demonstration of a Monolithic Micro-Spectrometer System
The starting design of a spectrometer based on a modified Czerny-Turner configuration containing five precision surfaces encapsulated in a monolithic structure is described. Since the purpose at the early stages of the development was to demonstrate the feasibility of the technology and not an attempt to address a specific sensing problem, the first substrate material chosen was optical quality polymethyl methacrylate (PMMA). The final system design decision was narrowed down to two possible configurations containing five and six precision surfaces. The five surface design was chosen since it contained one less precision optical surface, yet included multiple off-axis spheres. In this particular design and material system, the mass was kept below 7 g. The wavelength range (bandpass) design goal was 1 micrometer (0.6 - 1.6 micrometers). The PMMA is particularly transparent in this wavelength region and there are interesting effects to monitor within this band. The optical system was designed and optimized using the ZEMAX optical design software program to be entirely alignment free (self aligning)
Mycobacterium avium ssp. paratuberculosis detection in animals, food, water and other sources or vehicles of human exposure: A scoping review of the existing evidence
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Monolithic micro-spectrometer for low-cost sensing in materials processing
We have developed a monolithic micro-spectrometer suitable for a variety of sensing applications including industrial process monitoring. The device consists of a solid structure with a volume less than 6 cubic centimeters. All optical components of the spectrometer including two aspheric mirrors, a diffraction grating, and entrance and exit surfaces are fabricated onto the surface of the structure. All light paths are internally contained within the structure. The result is a small, rugged spectroscopic sensor ideally suited for use as a process monitor. Due to its monolithic nature the device requires no post-fabrication alignment; nor can it be knocked out of alignment during use. Although many materials and thus wavelength regions were possible, the prototype device discussed here was produced in PMMA by precision diamond turning. However, lower cost manufacturing approaches involving injection molding are under development to produce an affordable sensor. It is expected that modified versions of this sensor designs will be required for specific applications so as to maximize the performance and resolution over the operating range. For example, the prototype device described here operates over a wavelength range of 500 nm to 1000 nm. The performance of this device as a real-time surface monitoring sensor will be discussed in detail. Our approach of using wavelength dependent scattering resulted in the reduction to practice of a miniature, monolithic, rugged, low-cost, micro-instrument in a sensor sized package. The process sensor applications community has been faced by the cost versus performance issue. Simple go/no-go sensors are typically inexpensive but they provide very limited and sometimes dubious data. Scaled down traditional instruments offer very good measured information but are typically cost prohibitive, fragile, and still relatively large. This work will bridge the gap between these two extreme sensing alternatives
Factorial analysis of slaughter characteristics of fattening pigs fed different additives – Enzyme and probiotic in mixtures
To successfully investigate slaughter characteristics of fattening pigs fed in different ways, this experiment was carried out on Experimental Farm of the Institute for Animal Husbandry, Belgrade- Zemun. Investigation of correlation between slaughter traits of pigs fed with different additives in their nutrition was done by factorial analysis. Slaughter characteristics in three groups of fattening pigs fed in different ways were observed. The first group (variant 1) consisted of fatteners fed diets without any special additives. The second group (variant 2) consisted of pigs fed diets containing enzyme Rovabio, and the third group (variant 3) probiotic Lacture + Microbond. This study was aimed at coming to conclusion based on the results of factorial analysis of the observed traits to the greatest extent which determined slaughter traits of pigs fed diets containing different additives. The results obtained in general, that is, the structure of separated factors showed that different slaughter characteristics are realized with different nutrition.Key words: Fattening pigs, slaughter characteristics, enzyme Rovabio, probiotic Lacture + Microbond, factorial analysis
The effects of a 9-week hip focused weight training program on hip and knee kinematics and kinetics in experienced female dancers
Increased involvement of the hip musculature during some movements is associated with enhanced
performance and reduced injury risk. However, the impact of hip dominant weight training methods on
movement strategy has seen limited attention within the literature. The aim of this study was to evaluate if a
9-week hip dominant weight training intervention promotes a more hip dominant movement strategy leading
to an improvement in countermovement jump performance. Twenty-two experienced female dancers were
recruited and separated into an intervention (age 24.4 ± 6.3 years, body height 165.5 ± 5.8 cm, body mass 65.9
± 5.6 kg) and a control (age 22.9 ± 5.6 years, body height 163.3 ± 5.4 cm, body mass 57.4 ± 6.8 kg) group. The
intervention group participated in a 9-week hip dominant training intervention, which consisted of a wide
stance back squat, Romanian deadlift, hip thrusters, and a bent over row. Hip and knee kinematics and
kinetics, and countermovement jump performance were assessed pre and post training. Significant interaction
effects were found for peak hip joint moment (p = 0.030, η2 = 0.214) and countermovement jump performance
(p = 0.003, η2 = 0.356), indicating an increase in peak hip joint moment and countermovement jump
performance for the intervention group. Specifically, the intervention group showed a mean increase in jump
height of 11.5%. The data show that the use of a hip dominant weight training strategy can improve hip
contribution in the propulsion phase of the countermovement jump. Strength and conditioning specialists
should incorporate hip dominant weight training exercises to increase hip strength and improve performance
Critical review of interventions against Salmonella in the farm-to-processing pork production continuum
The purpose of this study was to identify, evaluate and summarize the available scientific literature on the effectiveness of interventions against Salmonella, in the farm-to-processing pork production continuum, following the principles of systematic review methodology
Summarizing the evidence of the performance of diagnostic tests for Salmonella spp. in swine: A systematic review approach
A systematic review was undertaken in order to identify, critically appraise and synthesize the existing literature on the diagnostic performance (e.g. Se and Sp of the test) and agreement (e.g. kappa and correlation coefficients) of conventional bacterial culture, enzyme-linked immunosorbent assays and polymerase chain reaction assays used to detect and monitor Salmonella spp. in swine. 2110 citations were identified and 160 were relevant to the research objectives. Quality assessment is complete for 150 of these references; 73 were excluded due to estimates of test performance not being clearly reported and insufficient raw data available for post-hoc analysis. Although the review is still in progress, early experiences indicate problems with lack of standardization in the design, conduct and reporting of studies of diagnostic test evaluation in this area. This review will provide valuable information by identifying gaps in existing research and providing direction for future work on the standardization of tests examined in this review
The influence of population density and duration of breeding on broiler chickens productivity and profitability
Fattening of broiler chickens is a very specific production process characterized by intensive production principles, rapid increase in broilers, small consumption of food/kg of gain (feed conversion ratio) and a large production of broilers’ meat per square meter of surface. In order to increase the profitability of this production, the intention of farmers is to reduce the duration of production as well as to increase population density, with the aim of increasing the production of broiler chickens’ meat,calculated per unit of surface (m2). However, most of the countries in the world, in order to protect and preserve the welfare of poultry, limit the maximum of broilers’ meat production by regulations and standards. These researches aim to determine the optimal density and duration of fattening in a way to achieve the best production results and the profitability of fattening the broiler chickens hybrids Cobb 500 in temperate continental climate, while preserving the welfare of poultry. From six different population densities (16.84, 16.33, 14.29, 12.75, 14.80 and 15.46 birds per m2) and fattening period between 37 and 40 days, the best production and economic performance showed that a group ofchickens that was fattened in a period of 40 days had a population density of about 16 birds per m2. This group of broilers produced the most meat per m2 (about 33 kg), the welfare of poultry is maintained and the standard was not exceeded, so we can say that the best economy and profitability of fattening broiler chickens in the concerned region is achieved. In other groups of chickens, profitability could be more advantageous if the increased population density goes up to 16 birds perm2; or the duration of fattening could be extended up to 40 days and by this way the welfare of poultry would not be violated
The role of marbling as an intrinsic characteristic at the point of meat purchase – the Taguchi approach
Meat quality is considered a complex concept depending on many characteristics that could be intrinsic or extrinsic. At the same time, intrinsic and extrinsic quality cues affect consumers' purchasing decisions. The importance of each quality cue was analysed and discussed in previous literature. Thus, colour and level of marbling of fresh meat were defined as key quality cues at the point of meat purchase. These characteristics are mostly related to pork and beef. The aim of this study was to identify quality characteristics that most closely match the consumer's preferences and at the same time could be related to quality losses. For that purpose, this paper gives a novel approach of the potential application of Taguchi loss function associated with quality characteristics and related losses for colour and level of marbling. This application can be implemented by providing a quality characteristic's proper target values and limits, which would make the meat production process more consistent
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