2,464 research outputs found
Anomalously strong pinning of the filling factor nu=2 in epitaxial graphene
We explore the robust quantization of the Hall resistance in epitaxial
graphene grown on Si-terminated SiC. Uniquely to this system, the dominance of
quantum over classical capacitance in the charge transfer between the substrate
and graphene is such that Landau levels (in particular, the one at exactly zero
energy) remain completely filled over an extraordinarily broad range of
magnetic fields. One important implication of this pinning of the filling
factor is that the system can sustain a very high nondissipative current. This
makes epitaxial graphene ideally suited for quantum resistance metrology, and
we have achieved a precision of 3 parts in 10^10 in the Hall resistance
quantization measurements
Influence of impurity spin dynamics on quantum transport in epitaxial graphene
Experimental evidence from both spin-valve and quantum transport measurements
points towards unexpectedly fast spin relaxation in graphene. We report
magnetotransport studies of epitaxial graphene on SiC in a vector magnetic
field showing that spin relaxation, detected using weak-localisation analysis,
is suppressed by an in-plane magnetic field, , and thereby
proving that it is caused at least in part by spinful scatterers. A
non-monotonic dependence of effective decoherence rate on
reveals the intricate role of scatterers' spin dynamics in forming the
interference correction to conductivity, an effect that has gone unnoticed in
earlier weak localisation studie
Disorder induced Dirac-point physics in epitaxial graphene from temperature-dependent magneto-transport measurements
We report a study of disorder effects on epitaxial graphene in the vicinity
of the Dirac point by magneto-transport. Hall effect measurements show that the
carrier density increases quadratically with temperature, in good agreement
with theoretical predictions which take into account intrinsic thermal
excitation combined with electron-hole puddles induced by charged impurities.
We deduce disorder strengths in the range 10.2 31.2 meV, depending on
the sample treatment. We investigate the scattering mechanisms and estimate the
impurity density to be cm for our samples.
An asymmetry in the electron/hole scattering is observed and is consistent with
theoretical calculations for graphene on SiC substrates. We also show that the
minimum conductivity increases with increasing disorder potential, in good
agreement with quantum-mechanical numerical calculations.Comment: 6 pages, 3 figure
Operation of graphene quantum Hall resistance standard in a cryogen-free table-top system
We demonstrate quantum Hall resistance measurements with metrological
accuracy in a small cryogen-free system operating at a temperature of around
3.8K and magnetic fields below 5T. Operating this system requires little
experimental knowledge or laboratory infrastructure, thereby greatly advancing
the proliferation of primary quantum standards for precision electrical
metrology. This significant advance in technology has come about as a result of
the unique properties of epitaxial graphene on SiC.Comment: 15 pages, 9 figure
Quantum Hall Effect and Quantum Point Contact in Bilayer-Patched Epitaxial Graphene
We study an epitaxial graphene monolayer with bilayer inclusions via
magnetotransport measurements and scanning gate microscopy at low temperatures.
We find that bilayer inclusions can be metallic or insulating depending on the
initial and gated carrier density. The metallic bilayers act as equipotential
shorts for edge currents, while closely spaced insulating bilayers guide the
flow of electrons in the monolayer constriction, which was locally gated using
a scanning gate probe.Comment: 5 pages, 5 figure
Effect of Systolic Blood Pressure on Left Ventricular Structure and Function A Mendelian Randomization Study
We aimed to estimate the effects of a lifelong exposure to high systolic blood pressure (SBP) on left ventricular (LV) structure and function using Mendelian randomization. A total of 5596 participants of the UK Biobank were included for whom cardiovascular magnetic resonance imaging and genetic data were available. Major exclusion criteria included nonwhite ethnicity, major cardiovascular disease, and body mass index >30 o
Practical nursing recommendations for palliative care for people with dementia living in long-term care facilities during the COVID-19 pandemic:A rapid scoping review
Background: The acute nature of COVID-19 and its effects on society in terms of social distancing and quarantine regulations affect the provision of palliative care for people with dementia who live in long-term care facilities. The current COVID-19 pandemic poses a challenge to nursing staff, who are in a key position to provide high-quality palliative care for people with dementia and their families. Objective: To formulate practice recommendations for nursing staff with regard to providing palliative dementia care in times of COVID-19. Design and method: A rapid scoping review following guidelines from the Joanna Briggs Institute. Eligible papers focused on COVID-19 in combination with palliative care for older people or people with dementia and informed practical nursing recommendations for long-term care facilities. After data extraction, we formulated recommendations covering essential domains in palliative care adapted from the National Consensus Project's Clinical Practice Guidelines for Quality Palliative Care. Data sources: We searched the bibliographic databases of PubMed, CINAHL and PsycINFO for academic publications. We searched for grey literature using the search engine Google. Moreover, we included relevant letters and editorials, guidelines, web articles and policy papers published by knowledge and professional institutes or associations in dementia and palliative care. Results: In total, 23 documents (7 (special) articles in peer-reviewed journals, 6 guides, 4 letters to editors, 2 web articles (blogs), 2 reports, a correspondence paper and a position paper) were included. The highest number of papers informed recommendations under the domains 'advance care planning' and 'psychological aspects of care'. The lowest number of papers informed the domains 'ethical care', 'care of the dying', 'spiritual care' and 'bereavement care'. We found no papers that informed the 'cultural aspects of care' domain. Conclusion: Literature that focuses specifically on palliative care for people with dementia in long-term care facilities during the COVID-19 pandemic is still largely lacking. Particular challenges that need addressing involve care of the dying and the bereaved, and ethical, cultural and spiritual aspects of care. Moreover, we must acknowledge grief and moral distress among nursing staff. Nursing leadership is needed to safeguard the quality of care and nursing staff should work together within an interprofessional care team to initiate advance care planning conversations in a timely manner, to review and document advance care plans, and to adapt goals of care as they may change due to the COVID-19 situation
ANALISIS FAKTOR – FAKTOR YANG MEMPENGARUHI KEPUASAN KONSUMEN DI DEPOT “ HOK LAY ” KOTA MALANG (Studi Pada Konsumen Depot “Hok Lay” Kota Malang)
Food is a basic human need besides clothing and shelter. In the modern era like today many people are more fond of eating food outside the home because it is considered faster and more practical.This makes the growth of the culinary business grow rapidly and the competition between culinary businesses (restaurants, cafes and so on) is getting tougher. The change in consumer tastes and behavior requires producers to be able to create satisfaction with their customers, so they can continue to survive in the market. One restaurant that is still holding is the "Hok Lay" Depot.
The objectives of this study are: 1) to find out whether the price, product, location, promotion, people, process and physical evidence factors have an influence on customer satisfaction in Malang's "Hok Lay" Depot, and 2) to find out which factors have influence the most dominant to customer satisfaction in Malang's "Hok Lay" Depot.Location determination is done purposively, namely in Malang "Hok Lay" Depot. The sampling method uses purposive sampling with 70 respondents. The method of analysis uses multiple linear regression tests with the help of SPSS version 22 software.
The results of the study of the objectives 1) The independent variable (marketing mix 7P) consisting of products, prices, locations, promotions, people, processes and physical evidence have a simultaneous or joint effect on customer satisfaction with a Fcount value of 23.382> 2.25 and the significance value 0,000 ≤ 0.05. 2) The variable that has the most dominant influence on consumer satisfaction "Hok Lay" Depot is the product variable. This hypothesis is obtained through the calculation of the dominant test with a Standardized Coefficient Beta value of 0.346
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