Low Temperature Drying With Air Dehumidified by Zeolite for Food Products: Energy Efficiency Aspect Analysis

Developments in low temperature drying of food products are still an interesting issue; especially with respect to the energy efficiency. This research studies the energy efficiency that can be achieved by a dryer using air which is dehumidified by zeolite. Experimental results are fitted to a dynamic model to find important variables for the drying operation. The results show that ambient air temperature as well as the ratio between air flow for drying and air flow for regeneration, affect the energy efficiency significantly. Relative humidity of used air, and shift time have a minor effect on the dryer performance. From the total work, it can be noted that the dryer efficiency operated at 50-60°C achieves 75 percent, which is attractive for drying of food products

ADOPTION OF VETERINARY SURGEON SERVICES BY SHEEP AND GOAT FARMERS IN QWAQWA

A number of technology transfer (diffusion) programmes involving amongst others veterinary surgeon services subsidised by the government, were launched in the former homelands of South Africa between 1980 and 1993. Many of these programmes were discontinued after the general election of 1994. In order to evaluate the adoption of technology in Qwaqwa, a former Sotho speaking homeland, two Logit models were fit using the conventional definition of an adopter and an adapted definition, which included potential adopters with the adopters. Where the conventional definition of adoption was estimated, livestock income per LSU, ram technology, roads and suppliers of livestock inputs are significant variables contributing to adoption. The results of the adapted model reveal that farming efficiency (weaning percentage), type of farmer (sheep as percentage of the total small ruminant herd) and ram technology, prove to be significant variables predicting adoption. It was also found that the characteristics of potential adopters gravitate more to adopters than to non-adopters. These results indicated that the adapted definition presented a more accurate prediction than the conventional definition. The results of this study indicate the policy necessary to further accelerate the diffusion of veterinary surgeon services by means of the development of a better infrastructure, the reintroduction of subsidised veterinary surgeon services at the sheering sheds as well as a better flow of information to farmers in Qwaqwa.Livestock Production/Industries,

High export via small particles before the onset of the North Atlantic spring bloom

Sinking organic matter in the North Atlantic Ocean transfers 1-3 Gt carbon year?1 from the surface ocean to the interior. The majority of this exported material is thought to be in form of large, rapidly sinking particles that aggregate during or after the spring phytoplankton bloom. However, recent work has suggested that intermittent water column stratification resulting in the termination of deep convection can isolate phytoplankton from the euphotic zone, leading to export of small particles. We present depth profiles of large (>0.1mm equivalent spherical diameter, ESD) and small (300m depth, leading to deep mixing of particles as deep as 600m. Subsequent re-stratification could trap these particles at depth and lead to high particle fluxes at depth without the need for aggregation (‘mixed layer pump'). Overall we suggest that pre-bloom fluxes to the mesopelagic are significant, and the role of small sinking particles requires careful consideration

On the spin-statistics connection in curved spacetimes

The connection between spin and statistics is examined in the context of locally covariant quantum field theory. A generalization is proposed in which locally covariant theories are defined as functors from a category of framed spacetimes to a category of $*$-algebras. This allows for a more operational description of theories with spin, and for the derivation of a more general version of the spin-statistics connection in curved spacetimes than previously available. The proof involves a "rigidity argument" that is also applied in the standard setting of locally covariant quantum field theory to show how properties such as Einstein causality can be transferred from Minkowski spacetime to general curved spacetimes.Comment: 17pp. Contribution to the proceedings of the conference "Quantum Mathematical Physics" (Regensburg, October 2014

Descriptively Adequate and Cognitively Plausible? Validating Distinctions between Types of Coherence Relations

A central issue in linguistics concerns the relationship between theories and evidence in data. We investigate this issue in the field of discourse coherence, and particularly the study of coherence relations such as causal and contrastive. Proposed inventories of coherence relations differ greatly in the type and number of proposed relations. Such proposals are often validated by focusing on either the descriptive adequacy (researcher’s intuitions on textual interpretations) or the cognitive plausibility of distinctions (empirical research on cognition). We argue that both are important, and note that the concept of cognitive plausibility is in need of a concrete definition and quantifiable operationalization. This contribution focuses on how the criterion of cognitive plausibility can be operationalized and presents a systematic validation approach to evaluate discourse frameworks. This is done by detailing how various sources of evidence can be used to support or falsify distinctions between coherence relational labels. Finally, we present methodological issues regarding verification and falsification that are of importance to all discourse researchers studying the relationship between theory and data

Learning inguinal hernia repair? A survey of current practice and of preferred methods of surgical residents

Purpose: During surgical residency, many learning methods are available to learn an inguinal hernia repair (IHR). This study aimed to investigate which learning methods are most commonly used and which are perceived as most important by surgical residents for open and endoscopic IHR. Methods: European general surgery residents were invited to participate in a 9-item web-based survey that inquired which of the learning methods were used (checking one or more of 13 options) and what their perceived importance was on a 5-point Likert scale (1 = completely not important to 5 = very important). Results: In total, 323 residents participated. The five most commonly used learning methods for open and endoscopic IHR were apprenticeship style learning in the operation room (OR) (98% and 96%, respectively), textbooks (67% and 49%, respectively), lectures (50% and 44%, respectively), video-demonstrations (53% and 66%, respectively) and journal articles (54% and 54%, respectively). The three most important learning methods for the open and endoscopic IHR were participation in the OR [5.00 (5.00–5.00) and 5.00 (5.00–5.00), respectively], video-demonstrations [4.00 (4.00–5.00) and 4.00 (4.00–5.00), respectively], and hands-on hernia courses [4.00 (4.00–5.00) and 4.00 (4.00–5.00), respectively]. Conclusion: This study demonstrated a discrepancy between learning methods that are currently used by surgical residents to learn the open and endoscopic IHR and preferred learning methods. There is a need for more emphasis on practising before entering the OR. This would support surgical residents’ training by first observing, then practising and finally performing the surgery in the OR

Coherent Phonon Dynamics in Short-Period InAs/GaSb Superlattices

We have performed ultrafast pump-probe spectroscopy studies on a series of InAs/GaSb-based short-period superlattice (SL) samples with periods ranging from 46 \AA to 71 \AA. We observe two types of oscillations in the differential reflectivity with fast ($\sim$ 1- 2 ps) and slow ($\sim$ 24 ps) periods. The period of the fast oscillations changes with the SL period and can be explained as coherent acoustic phonons generated from carriers photoexcited within the SL. This mode provides an accurate method for determining the SL period and assessing interface quality. The period of the slow mode depends on the wavelength of the probe pulse and can be understood as a propagating coherent phonon wavepacket modulating the reflectivity of the probe pulse as it travels from the surface into the sample.Comment: 6 pages, 4 figure

High export via small particles before the onset of the North Atlantic spring bloom

Sinking organic matter in the North Atlantic Ocean transfers 1-3 Gt carbon year?1 from the surface ocean to the interior. The majority of this exported material is thought to be in form of large, rapidly sinking particles that aggregate during or after the spring phytoplankton bloom. However, recent work has suggested that intermittent water column stratification resulting in the termination of deep convection can isolate phytoplankton from the euphotic zone, leading to export of small particles. We present depth profiles of large (&gt;0.1mm equivalent spherical diameter, ESD) and small (&lt;0.1mm ESD) sinking particle concentrations and fluxes prior to the spring bloom at two contrasting sites in the North Atlantic (61°30N, 11°00W and 62°50N, 02°30W) derived from the Marine Snow Catcher and the Video Plankton Recorder. The downward flux of organic carbon via small particles ranged from 23-186 mg C m?2 d?1, often constituting the bulk of the total particulate organic carbon flux. We propose that these rates were driven by two different mechanisms: In the Norwegian Basin, small sinking particles likely reached the upper mesopelagic by disaggregation of larger, faster sinking particles. In the Iceland Basin, a storm deepened the mixed layer to &gt;300m depth, leading to deep mixing of particles as deep as 600m. Subsequent re-stratification could trap these particles at depth and lead to high particle fluxes at depth without the need for aggregation (‘mixed layer pump'). Overall we suggest that pre-bloom fluxes to the mesopelagic are significant, and the role of small sinking particles requires careful consideration. <br/

An analogue of the Coleman-Mandula theorem for quantum field theory in curved spacetimes

The Coleman-Mandula (CM) theorem states that the Poincaré and internal symmetries of a Minkowski spacetime quantum field theory cannot combine nontrivially in an extended symmetry group. We establish an analogous result for quantum field theory in curved spacetimes, assuming local covariance, the timeslice property, a local dynamical form of Lorentz invariance, and additivity. Unlike the CM theorem, our result is valid in dimensions n≥2 and for free or interacting theories. It is formulated for theories defined on a category of all globally hyperbolic spacetimes equipped with a global coframe, on which the restricted Lorentz group acts, and makes use of a general analysis of symmetries induced by the action of a group G on the category of spacetimes. Such symmetries are shown to be canonically associated with a cohomology class in the second degree nonabelian cohomology of G with coefficients in the global gauge group of the theory. Our main result proves that the cohomology class is trivial if G is the universal cover S of the restricted Lorentz group. Among other consequences, it follows that the extended symmetry group is a direct product of the global gauge group and S, all fields transform in multiplets of S, fields of different spin do not mix under the extended group, and the occurrence of noninteger spin is controlled by the centre of the global gauge group. The general analysis is also applied to rigid scale covariance