8,199 research outputs found

    Organic farming without fossil fuels - life cycle assessment of two Swedish cases

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    Organic agriculture is dependent on fossil fuels, just like conventional agriculture, but this can be reduced by the use of on-farm biomass resources. The energy efficiency and environmental impacts of different alternatives can be assessed by life cycle assessment (LCA), which we have done in this project. Swedish organic milk production can become self-sufficient in energy by using renewable sources available on the farm, with biogas from manure as the main energy source. Thereby greenhouse gas (GHG) emissions from the production system can be reduced, both by substituting fossil fuels and by reducing methane emissions from manure. The arable organic farm studied in the project could be self-sufficient in energy by using the residues available in the crop rotation. Because of soil carbon losses, the greenhouse gas emission savings were lower with the use of straw ethanol, heat and power (9%) than by using ley for biogas production (35%). In this research project, the system boundaries were set at energy self-sufficiency at farm or farm-cluster level. Heat and fuel were supplied as needed, and electricity production was equal to use on an annual basis. In practice, however, better resource efficiency can be achieved by making full use of available energy infrastructure, and basing production on resource availability and economic constraints, rather than a narrow self-sufficiency approach

    Boards strategizing in liminal spaces: Process and practice, formal and informal.

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    Boards operate notionally in a liminal, nonhierarchical space, neither inside the company nor outside, creating ambiguity between service and control functions and fostering tolerance of it. With repeated corporate governance crises, however, new prescriptions institutionalized in law, regulation, and codes of conduct have added significance to the control side, marked by monitoring and compliance tasks. Taking a cue from the strategy process and strategy-as-practice literatures, this study revisits the work of directors on the service side: their engagement in strategizing. Formalization of board processes has led to greater structure and reduced the liminality of the board. Using interviews with 20 directors from a range of organization types, this study finds that directors experiment respond to increased institutionalization of board practice by seeking out new liminal spaces and informal practices, with implications for theory of boards, board activities, and public policy

    Traditional Cultural Districts: An Opportunity for Alaska Tribes to Protect Subsistence Rights and Traditional Lands

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    Alaska tribes have limited control over their traditional lands and waters. Tribes may increase their influence through a Traditional Cultural District designation under Section 106 of the National Historic Preservation Act. This designation does not stop development, but requires federal agencies to consult with tribes regarding potential development that may impact the district. The consultation right applies regardless of whether a tribe owns or has formally designated the district. In Alaska, where no Traditional Cultural Districts exist as of 2014, there is potential for designating large areas of land or water that correspond to the range of traditionally important species

    Comparison of the beta-alpha angular correlations in the Li8 and B8 beta decays, and the conserved vector current theory

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    This paper describes a comparison of the beta-alpha angular correlations of the beta decays of Li8 and B8 to the 2.90-Mev alpha-unstable level of Be8. The data were fitted to an angular correlation in the laboratory system of the form W(θβα)=1+Acosθβα+Bcos2θβα, where A and B were independently determined for the Li8 and B8 beta decays from measurements at θβα=0°, 90°, and 180°. The coefficients A are due to the recoil of Be8* and have the same sign for both beta decays. The coefficients B arise from the interference of forbidden vector matrix elements with the allowed axial vector matrix element and have different signs in the two decays. The correlation for the Li8 decay was measured with average total beta energies, Wβ~5, 8, and 11 Mev. Both A and B were found to be approximately linear in Wβ. The correlation for the B8 decay was measured only with average Wβ~11 Mev. From the data with Wβ~11 Mev, the difference of the coefficients, B(Li8)-B(B8), equals (0.0070±0.0012)Wβ. This result is compared with theoretical predictions based on the older Fermi and the newer conserved vector current theories of beta decay. The experiment agrees with the prediction of the latter theory

    Knowledge creation and management in the five LHC experiments at CERN: implications for technology innovation and transfer

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    The present study analyses knowledge creation, acquisition and transfer in the five LHC physics experiments at CERN: ALICE, ATLAS, CMS, LHCb, and TOTEM. A questionnaire was provided during collaboration meetings and a total of 291 replies were obtained and analysed. The results of this research study provide evidence that the social process of participation in meetings, acquisition of skills in different areas, and the development of interests by interaction with colleagues are key elements of the learning process. Furthermore, the results indicate that knowledge acquisition in a multicultural environment plays a mediating role in the interaction between social capital constructs (social interaction, relationship quality, and network ties) and competitive advantage outcomes (invention development and technological distinctiveness). Social interaction, relationship quality, and network ties are connected to greater knowledge acquisition, and also contribute to innovation and transfer of the knowledge to industry. The fertile environment of the five LHC experiments building and managing multiple processes, involves a dynamic, interactive,and simultaneous exchange of knowledge both inside and outside their organization

    Double quantum dot with tunable coupling in an enhancement-mode silicon metal-oxide semiconductor device with lateral geometry

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    We present transport measurements of a tunable silicon metal-oxide-semiconductor double quantum dot device with lateral geometry. Experimentally extracted gate-to-dot capacitances show that the device is largely symmetric under the gate voltages applied. Intriguingly, these gate voltages themselves are not symmetric. Comparison with numerical simulations indicates that the applied gate voltages serve to offset an intrinsic asymmetry in the physical device. We also show a transition from a large single dot to two well isolated coupled dots, where the central gate of the device is used to controllably tune the interdot coupling.Comment: 4 pages, 3 figures, to be published in Applied Physics Letter

    Analysis of Congestion Control

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    Agents must work. Given the trends in elec- tronic models, programmers particularly note the construction of the lookaside buffer, which embodies the theoretical principles of dis- tributed systems. In order to overcome this chal- lenge, we consider how the Turing machine can be applied to the simulation of the UNIVAC computer

    Enhancement mode double top gated MOS nanostructures with tunable lateral geometry

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    We present measurements of silicon (Si) metal-oxide-semiconductor (MOS) nanostructures that are fabricated using a process that facilitates essentially arbitrary gate geometries. Stable Coulomb blockade behavior free from the effects of parasitic dot formation is exhibited in several MOS quantum dots with an open lateral quantum dot geometry. Decreases in mobility and increases in charge defect densities (i.e. interface traps and fixed oxide charge) are measured for critical process steps, and we correlate low disorder behavior with a quantitative defect density. This work provides quantitative guidance that has not been previously established about defect densities for which Si quantum dots do not exhibit parasitic dot formation. These devices make use of a double-layer gate stack in which many regions, including the critical gate oxide, were fabricated in a fully-qualified CMOS facility.Comment: 11 pages, 6 figures, 3 tables, accepted for publication in Phys. Rev.

    Surgical Management of Inguinal Hernias at Bugando Medical Centre in Northwestern Tanzania: Our Experiences in a Resource-Limited Setting.

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    Inguinal hernia repair remains the commonest operation performed by general surgeons all over the world. There is paucity of published data on surgical management of inguinal hernias in our environment. This study is intended to describe our own experiences in the surgical management of inguinal hernias and compare our results with that reported in literature. A descriptive prospective study was conducted at Bugando Medical Centre in northwestern Tanzania. Ethical approval to conduct the study was obtained from relevant authorities before the commencement of the study. Statistical data analysis was done using SPSS software version 17.0. A total of 452 patients with inguinal hernias were enrolled in the study. The median age of patients was 36 years (range 3 months to 78 years). Males outnumbered females by a ratio of 36.7:1. This gender deference was statistically significant (P=0.003). Most patients (44.7%) presented late (more than five years of onset of hernia). Inguinoscrotal hernia (66.8%) was the commonest presentation. At presentation, 208 (46.0%) patients had reducible hernia, 110 (24.3%) had irreducible hernia, 84 (18.6%) and 50(11.1%) patients had obstructed and strangulated hernias respectively. The majority of patients (53.1%) had right sided inguinal hernia with a right-to-left ratio of 2.1: 1. Ninety-two (20.4%) patients had bilateral inguinal hernias. 296 (65.5%) patients had indirect hernia, 102 (22.6%) had direct hernia and 54 (11.9%) had both indirect and direct types (pantaloon hernia). All patients in this study underwent open herniorrhaphy. The majority of patients (61.5%) underwent elective herniorrhaphy under spinal anaesthesia (69.2%). Local anaesthesia was used in only 1.1% of cases. Bowel resection was required in 15.9% of patients. Modified Bassini's repair (79.9%) was the most common technique of posterior wall repair of the inguinal canal. Lichtenstein mesh repair was used in only one (0.2%) patient. Complication rate was 12.4% and it was significantly higher in emergency herniorrhaphy than in elective herniorrhaphy (P=0.002). The median length of hospital stay was 8 days and it was significantly longer in patients with advanced age, delayed admission, concomitant medical illness, high ASA class, the need for bowel resection and in those with surgical repair performed under general anesthesia (P<0.001). Mortality rate was 9.7%. Longer duration of symptoms, late hospitalization, coexisting disease, high ASA class, delayed operation, the need for bowel resection and presence of complications were found to be predictors of mortality (P<0.001). Inguinal hernias continue to be a source of morbidity and mortality in our centre. Early presentation and elective repair of inguinal hernias is pivotal in order to eliminate the morbidity and mortality associated with this very common problem
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