4,794 research outputs found
Anaerobic Digestion of Cereal Rye Cover Crop
The rapid growth of cover crop planting area in the U.S. helps with erosion control, soil health, control of greenhouse gases, and also provides abundant biomass for the production of bioenergy and bioproducts. Given the cover crops’ compositional heterogeneity and variability, a tolerate platform technology such as anaerobic digestion (AD) is preferred but has not been widely used for cover crop biorefining. This study evaluated the biogas and methane yields from six cereal rye (Secale cereale L.) cover crops grown in the Midwest, using both bench- and pilot-scale anaerobic digesters. The effects of two critical factors, the total solids (TS) content and ensiling, on digester performance were also investigated. Methane yields of 174.79–225.23 L/kg-VS were obtained from the bench-scale tests using cereal rye as the mono feedstock. The pilot-scale test with no pH adjustment showed a slightly higher methane yield. Ensiling increased the methane yield by 23.08% at 6% TS, but disturbed AD at 8% TS, and failed AD at 10% and 15% TS. Findings from this study would help farmers and the biorefining industry to determine the baseline performance and revenue of cereal rye AD and to develop strategies for process control and optimization
Pengaruh Jumlah Dan Kriteria Buah Muda Yang Dipertahankan Terhadap Hasil Buah Mangga ( Effect of Number and Criteria of Maintained Young Fruits on Yield of Mango)
The aim of this research was to get optimum number of maintained young fruit per panicle and good criteria of fruit that must be maintained so it will get a high yield of mango. The factors under investigation were number of young fruit to be maintained per panicle: 2, 4, and 6; the criteria of young fruit to be maintained: the biggest fruit, fruit attached at the beginning of panicle, and fruit attached at panicle at the same distance. The result of research showed that 6 fruits that maintained per panicle gave the highest weight per tree of mango (33,45 kg), but the lowest weight per fruit (466,98 kg). Maintaining the 2 biggest fruits of mango gave the highest weight per fruit (510,53 g)
Development Of An Adaptive Augmented Reality Qualification System For Manual Assembly And Maintenance
The manufacturing industry is facing various challenges today - globalization, fast-moving sales markets, short product life cycles, individualization, mass production and diversity of variants are trends that will continue or even increase in the future. Speed and flexibility in production are thus becoming important success factors for companies. To meet the demands of the market, there is a growing necessity to deploy employees flexibly within the production process. This increases the need for additional qualification of workers. By overlaying reality with virtual cues, Head-mounted displays (HMD) can present information in a situation-specific and location-linked manner. Data glasses also offer a high and convertible degree of support through the possibility of providing different media forms while both hands are available at the same time. Augmented Reality (AR) guidance systems are already available on the market and are suitable as permanent assistance systems, but only to a limited extent for qualification aspects. An industrially applicable qualification software that collects expert knowledge from skilled workers and then makes it available to new or inexperienced employees in an adaptive way that promotes learning is currently not available. This paper therefore presents the development of the software AQUA, which taps internal expertise with low effort and creates training courses that convey learning content to learners without over- or under-challenging them
The process of prioritization of non-communicable diseases in the global health policy arena.
Although non-communicable diseases (NCDs) are the leading cause of morbidity and mortality worldwide, the global policy response has not been commensurate with their health, economic and social burden. This study examined factors facilitating and hampering the prioritization of NCDs on the United Nations (UN) health agenda. Shiffman and Smith's (Generation of political priority for global health initiatives: a framework and case study of maternal mortality. The Lancet 370: 1370-9.) political priority framework served as a structure for analysis of a review of NCD policy documents identified through the World Health Organization's (WHO) NCD Global Action Plan 2013-20, and complemented by 11 semi-structured interviews with key informants from different sectors. The results show that a cohesive policy community exists, and leaders are present, however, actor power does not extend beyond the health sector and the role of guiding institutions and civil society have only recently gained momentum. The framing of NCDs as four risk factors and four diseases does not necessarily resonate with experts from the larger policy community, but the economic argument seems to have enabled some traction to be gained. While many policy windows have occurred, their impact has been limited by the institutional constraints of the WHO. Credible indicators and effective interventions exist, but their applicability globally, especially in low- and middle-income countries, is questionable. To be effective, the NCD movement needs to expand beyond global health experts, foster civil society and develop a broader and more inclusive global governance structure. Applying the Shiffman and Smith framework for NCDs enabled different elements of how NCDs were able to get on the UN policy agenda to be disentangled. Much work has been done to frame the challenges and solutions, but implementation processes and their applicability remain challenging globally. NCD responses need to be adapted to local contexts, focus sufficiently on both prevention and management of disease, and have a stronger global governance structure
National innovation and knowledge performance: The role of higher education teaching and training
This paper acknowledges the role of the higher education system (HES) in the production of knowledge and human capital. However, most of the literature attributes this production to the second (research activities) and third (exploitation of teaching and research activities) mission. This paper proposes to investigate the under explored role of the first mission (teaching) of HES in the production of national innovation
Quarkonium dissociation by anisotropy
We compute the screening length for quarkonium mesons moving through an
anisotropic, strongly coupled N=4 super Yang-Mills plasma by means of its
gravity dual. We present the results for arbitrary velocities and orientations
of the mesons, as well as for arbitrary values of the anisotropy. The
anisotropic screening length can be larger or smaller than the isotropic one,
and this depends on whether the comparison is made at equal temperatures or at
equal entropy densities. For generic motion we find that: (i) mesons dissociate
above a certain critical value of the anisotropy, even at zero temperature;
(ii) there is a limiting velocity for mesons in the plasma, even at zero
temperature; (iii) in the ultra-relativistic limit the screening length scales
as with \epsilon =1/2, in contrast with the isotropic result
\epsilon =1/4.Comment: 39 pages, 26 figures; v2: minor changes, added reference
Weak Field Black Hole Formation in Asymptotically AdS Spacetimes
We use the AdS/CFT correspondence to study the thermalization of a strongly
coupled conformal field theory that is forced out of its vacuum by a source
that couples to a marginal operator. The source is taken to be of small
amplitude and finite duration, but is otherwise an arbitrary function of time.
When the field theory lives on , the source sets up a
translationally invariant wave in the dual gravitational description. This wave
propagates radially inwards in space and collapses to form a black
brane. Outside its horizon the bulk spacetime for this collapse process may
systematically be constructed in an expansion in the amplitude of the source
function, and takes the Vaidya form at leading order in the source amplitude.
This solution is dual to a remarkably rapid and intriguingly scale dependent
thermalization process in the field theory. When the field theory lives on a
sphere the resultant wave either slowly scatters into a thermal gas (dual to a
glueball type phase in the boundary theory) or rapidly collapses into a black
hole (dual to a plasma type phase in the field theory) depending on the time
scale and amplitude of the source function. The transition between these two
behaviors is sharp and can be tuned to the Choptuik scaling solution in
.Comment: 50 pages + appendices, 6 figures, v2: Minor revisions, references
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Gel-Electrophoresis and Diffusion of Ring-Shaped DNA
A model for the motion of ring-shaped DNA in a gel is introduced and studied
by numerical simulations and a mean-field approximation. The ring motion is
mediated by finger-shaped loops (hernias) that move in an amoeba-like fashion
around the gel obstructions. This constitutes an extension of previous
reptation tube treatments. It is shown that tension is essential for describing
the dynamics in the presence of hernias. It is included in the model as long
range interactions over stretched DNA regions. The mobility of ring-shaped DNA
is found to saturate much as in the well-studied case of linear DNA.
Experiments in polymer gels, however, show that the mobility drops
exponentially with the DNA ring size. This is commonly attributed to
dangling-ends in the gel that can impale the ring. The predictions of the
present model are expected to apply to artificial 2D obstacle arrays (W.D.
Volkmuth, R.H. Austin, Nature 358,600 (1992)) which have no dangling-ends. In
the zero-field case an exact solution of the model steady-state is obtained,
and quantities such as the average ring size are calculated. An approximate
treatment of the ring dynamics is given, and the diffusion coefficient is
derived. The model is also discussed in the context of spontaneous symmetry
breaking in one dimension.Comment: 8 figures, LaTeX, Phys. Rev. E - in pres
Behind the stiff upper lip: war narratives of older men with dementia.
The concept of the stiff upper lip stands as a cultural metaphor for the repression and figurative ¿biting back¿ of traumatic experience, particularly in military contexts. For men born in the first half of the 20th century, maintaining a stiff upper lip involved the ability to exert high levels of cognitive control over the subjective, visceral and emotional domains of experience. In the most common forms of dementia, which affect at least one in five men now in their 80s and 90s, this cognitive control is increasingly lost. One result is that, with the onset of dementia, men who have in the intervening years maintained a relative silence about their wartime experiences begin to disclose detailed memories of such events, in some cases for the first time. This article draws on narrative biographical data from three men with late-onset dementia who make extensive reference to their experience of war. The narratives of Sid, Leonard and Nelson are used to explore aspects of collective memory of the two World Wars, and the socially constructed masculinities imposed on men who grew up and came of age during those decades. The findings show that in spite of their difficulties with short term memory, people with dementia can contribute rich data to cultural studies research. Some aspects of the narratives discussed here may also be considered to work along the line of the counter-hegemonic, offering insights into lived experiences of war that have been elided in popular culture in the post-War years
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A tunable electrochromic fabry-perot filter for adaptive optics applications.
The potential for electrochromic (EC) materials to be incorporated into a Fabry-Perot (FP) filter to allow modest amounts of tuning was evaluated by both experimental methods and modeling. A combination of chemical vapor deposition (CVD), physical vapor deposition (PVD), and electrochemical methods was used to produce an ECFP film stack consisting of an EC WO{sub 3}/Ta{sub 2}O{sub 5}/NiO{sub x}H{sub y} film stack (with indium-tin-oxide electrodes) sandwiched between two Si{sub 3}N{sub 4}/SiO{sub 2} dielectric reflector stacks. A process to produce a NiO{sub x}H{sub y} charge storage layer that freed the EC stack from dependence on atmospheric humidity and allowed construction of this complex EC-FP stack was developed. The refractive index (n) and extinction coefficient (k) for each layer in the EC-FP film stack was measured between 300 and 1700 nm. A prototype EC-FP filter was produced that had a transmission at 500 nm of 36%, and a FWHM of 10 nm. A general modeling approach that takes into account the desired pass band location, pass band width, required transmission and EC optical constants in order to estimate the maximum tuning from an EC-FP filter was developed. Modeling shows that minor thickness changes in the prototype stack developed in this project should yield a filter with a transmission at 600 nm of 33% and a FWHM of 9.6 nm, which could be tuned to 598 nm with a FWHM of 12.1 nm and a transmission of 16%. Additional modeling shows that if the EC WO{sub 3} absorption centers were optimized, then a shift from 600 nm to 598 nm could be made with a FWHM of 11.3 nm and a transmission of 20%. If (at 600 nm) the FWHM is decreased to 1 nm and transmission maintained at a reasonable level (e.g. 30%), only fractions of a nm of tuning would be possible with the film stack considered in this study. These tradeoffs may improve at other wavelengths or with EC materials different than those considered here. Finally, based on our limited investigation and material set, the severe absorption associated with the refractive index change suggests that incorporating EC materials into phase correcting spatial light modulators (SLMS) would allow for only negligible phase correction before transmission losses became too severe. However, we would like to emphasize that other EC materials may allow sufficient phase correction with limited absorption, which could make this approach attractive
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