7,417 research outputs found
Comment on "Neutron Interferometric Observation of Noncyclic Phase"
A critique of a recent experiment [Wagh et.al., Phys.Rev.Lett.81, 1992 (7 Sep
1998)] to measure the noncyclic phase associated with a precessing neutron spin
in a neutron interferometer, as given by the Pancharatnam criterion, is
presented. It is pointed out that since the experiment measures, not the
noncyclic phase itself, but a quantity derived from it, it misses the most
interesting feature of such a phase, namely the different sign associated with
states lying in the upper and the lower hemispheres, a feature originating in
the existence of a phase singularity. Such effects have earlier been predicted
and seen in optical interference experiments using polarization of light as the
spinor [Bhandari, Phys.Rep.281, 1 (Mar 1997)].Comment: 5 pages, 0 figures, submitted to Phys.Rev.Let
Observable Dirac-type singularities in Berry's phase and the monopole
The physical reality and observability of 2n\pi Berry phases, as opposed to
the usually considered modulo 2\pi topological phases is demonstrated with the
help of computer simulation of a model adiabatic evolution whose parameters are
varied along a closed loop in the parameter space. Using the analogy of Berry's
phase with the Dirac monopole, it is concluded that an interferometer loop
taken around a magnetic monopole of strength n/2 yields an observable 2n\pi
phase shift, where n is an integer. An experiment to observe the effect is
proposed.Comment: 12 pages Latex, 3 postscript figures; submitted to Physical Review
Letters 15 September 2000; revised 19 November 200
Factors Affecting the Productivity of Coffee in Gulmi and Arghakhanchi Districts of Nepal
Coffee is one of the major potential cash crops with lucrative export value grown in mid-hills of Nepal. Nepalese coffee production has suffered long by low productivity. Research was conducted from February to May, 2019 to analyze the factors affecting the productivity of coffee in Arghakhanchi and Gulmi districts of Nepal. These two districts were, purposively selected for this study taking account of comparative advantage and past studies recommendations for coffee sector. Altogether, 100 coffee growing households 50 from each, Arghakhanchi and Gulmi, were sampled by using multistage sampling technique. A pre-tested semi-structured interview schedule was used to collect the primary information while secondary information was collected reviewing the relevant publications. Ordinary Least Square (OLS) regression model was used to determine the factors affecting the productivity of coffee. The study revealed that the number of active family members involved in coffee production (0.000), adoption of income diversification through intercropping (0.005), training (0.072) and technical assistance (0.021) had positive and significant effect on coffee productivity. Encouraging the household to have coffee production as their primary occupation, providing technical assistance on rational land utilization and intercropping and strengthening the skill and knowledge of farmers through trainings could significantly support in increasing the productivity of coffee
Legal regulation in empirical research in the Information Systems Basket of 8 Journals:a systematic literature review
Abstract. The core content of the paper lies in exploring how studies in information systems research address the topic of legal regulation. This study intends to fill the main gap in knowledge by aiming at the empirical studies within the basket of 8 journals that studies legal regulation. The results of this study provide perspectives on specific legal regulations, the research methodologies employed in empirical studies, and the theoretical foundations of the policy cycle stages to which these studies belong. This research identifies and presents a general overview of the trends in the information systems domain.
This thesis utilizes a systematic literature review to discover, examine, and extract empirical studies relevant to legal regulation from a basket of eight journals. The data were obtained from the SCOPUS database, resulting in 351 studies. Through the inclusion/exclusion criteria, 33 primary studies were identified that were relevant to the focus of the study. These primary studies focused on various legal regulations and were subsequently classified into four themes: impact, implementation, compliance, and policies. These themes allow for the identification of trends and the scope of the primary studies that investigate legal regulations. Furthermore, these themes are further analyzed and classified into sub-categories to provide a more detailed analysis of the primary studies.
The results of the study indicate that many primary studies within the empirical research follow qualitative research methodology. Among these primary studies, the legal regulations most frequently examined are from the United States. Several studies focus on regulations such as the Sarbanes-Oxley Act, High-Frequency Trading Act, and the Health Insurance Portability and Accountability Act. Following the United States, the study finds that primary studies also explore legal regulations in Europe, with a notable emphasis on the General Data Protection Regulation and the Markets in Financial Instruments Directive. However, the results also highlight that many primary studies belong to the implementation phase of the policy cycle stage, while none specifically focus on the problem identification stage.
The findings of the study broaden the opportunity to investigate how legal regulation has been addressed in journals beyond the selected basket of eight. Additionally, since this paper focuses solely on empirical evidence, most primary studies relied on qualitative research methodologies. This suggests the potential for exploring other studies that utilize methodologies such as design science or theoretical analysis
How good is the orthopaedic literature?
Randomized trials constitute approximately 3% of the orthopaedic literature Concerns regarding quality of the orthopaedic literature stem from a widespread notion that the overall quality of the surgical literature is in need of improvement. Limitations in surgical research arises primarily from two pervasive issues: 1) A reliance on low levels of evidence to advance surgical knowledge, and 2) Poor reporting quality among the high level surgical evidence that is available. The scarcity of randomized trials may be largely attributable to several unique challenges which make them difficult to conduct. We present characteristics of the orthopaedic literature and address the challenges of conducting randomized trials in surgery
Relation between geometric phases of entangled bi-partite systems and their subsystems
This paper focuses on the geometric phase of entangled states of bi-partite
systems under bi-local unitary evolution. We investigate the relation between
the geometric phase of the system and those of the subsystems. It is shown that
(1) the geometric phase of cyclic entangled states with non-degenerate
eigenvalues can always be decomposed into a sum of weighted non-modular pure
state phases pertaining to the separable components of the Schmidt
decomposition, though the same cannot be said in the non-cyclic case, and (2)
the geometric phase of the mixed state of one subsystem is generally different
from that of the entangled state even by keeping the other subsystem fixed, but
the two phases are the same when the evolution operator satisfies conditions
where each component in the Schmidt decomposition is parallel transported
Anaerobic Biotransformation of Aromatic and Polycyclic Aromatic Hydrocarbons in Soil Microcosms: A Review
Industrial activities introduce a wide variety of xenobiotic aromatic compounds into the biosphere. These aromatic and polycyclic aromatic compounds find their way into anaerobic marine and freshwater sediments, saturated aquifers, and waterlogged soils where neither their impact on carbon flow nor their propensity to persist is clearly understood. Although some halogenated aromatic compounds are degraded via anaerobic pathways, anaerobic transformation of aromatics remains limited to a small range of chemicals. This paper reviews anaerobic transformation processes for aromatic compounds, particularly polycyclic aromatic hydrocarbons (PAHs) in soil microcosms. A simplified pathway of PAH biotransformation and a conceptual pathway of PAH degradation under different redox-conditions are presented
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