scholarly journals Precision measurement and frequency metrology with ultracold atoms

2016 ◽  
Vol 3 (2) ◽  
pp. 189-200 ◽  
Author(s):  
Xibo Zhang ◽  
Jun Ye
Keyword(s):  
Precision Measurement ◽  
Optical Lattice ◽  
Ultracold Atoms ◽  
Measurement Precision ◽  
Future Research ◽  
Total Uncertainty ◽  
Research Activities ◽  
Systematic Effects ◽  
Optical Lattice Clock ◽  
Frequency Metrology

Abstract Precision measurement and frequency metrology have pushed many scientific and technological frontiers in the field of atomic, molecular and optical physics. In this article, we provide a brief review on the recent development of optical atomic clocks, with an emphasis placed on the important inter-dependence between measurement precision and systematic effects. After presenting a general discussion on the motivation and techniques behind the development of optical lattice clocks, where the use of many atoms greatly enhances the measurement precision, we present the JILA strontium optical lattice clock as the leading system of frequency metrology with the lowest total uncertainty, and we describe other related research activities. We discuss key ingredients that have enabled the optical lattice clocks with ultracold atoms to reach the 18th digit in both precision and accuracy. Furthermore, we discuss extending the power of precision clock spectroscopy to study quantum many-body physics and to provide control for atomic quantum materials. In addition, we explore future research directions that have the potential to achieve even greater precision.

Precision measurement of fermionic collisions using an 87Sr optical lattice clock with 1 × 10-16 inaccuracy

2010 ◽  
Vol 57 (3) ◽  
pp. 574-582 ◽  
Author(s):  
M.D. Swallows ◽  
G.K. Campbell ◽  
A.D. Ludlow ◽  
M.M. Boyd ◽  
J.W. Thomsen ◽  
...  
Keyword(s):  
Precision Measurement ◽  
Optical Lattice ◽  
Optical Lattice Clock

scholarly journals A Fermi-degenerate three-dimensional optical lattice clock

Science ◽  
2017 ◽  
Vol 358 (6359) ◽  
pp. 90-94 ◽  
Author(s):  
S. L. Campbell ◽  
R. B. Hutson ◽  
G. E. Marti ◽  
A. Goban ◽  
N. Darkwah Oppong ◽  
...  
Keyword(s):  
Optical Lattice ◽  
Three Dimensional ◽  
Measurement Precision ◽  
Frequency Shifts ◽  
Degenerate Fermi Gas ◽  
Atomic Interactions ◽  
Optical Lattice Clock ◽  
Clock Stability ◽  
Averaging Time ◽  
Clock Comparison

Strontium optical lattice clocks have the potential to simultaneously interrogate millions of atoms with a high spectroscopic quality factor of 4 × 1017. Previously, atomic interactions have forced a compromise between clock stability, which benefits from a large number of atoms, and accuracy, which suffers from density-dependent frequency shifts. Here we demonstrate a scalable solution that takes advantage of the high, correlated density of a degenerate Fermi gas in a three-dimensional (3D) optical lattice to guard against on-site interaction shifts. We show that contact interactions are resolved so that their contribution to clock shifts is orders of magnitude lower than in previous experiments. A synchronous clock comparison between two regions of the 3D lattice yields a measurement precision of 5 × 10–19 in 1 hour of averaging time.

SME’s Performance Through Comparative Performance Indicators, Measured by Business Statistics- Albania Case

2017 ◽  
Vol 9 (1) ◽  
pp. 361
Author(s):  
Godiva Rembeci
Keyword(s):  
Economic Performance ◽  
National Economy ◽  
Performance Indicators ◽  
Future Research ◽  
Productivity Measurement ◽  
Comparative Performance ◽  
Global Consensus ◽  
Research Activities ◽  
Business Statistics ◽  
National Economies

Now days there is a global consensus among all stakeholders that SMEs represent a driving force to the overall economic development, due to their significant contribution both on GDP and employment of national economies. SMEs also by numbers dominate the world business stage, although their contribution does vary among the countries. SMEs in Albania represents about 98% of the total enterprises with a contribution to national GDP for about 70%. The structure and the performance of national economy is depended very much on the economic performance and contribution of SME, that’s why most of the governments have strategic programmes which support the SME’s development. To measure SMEs’ performance and their ability to compete on national and international markets requires a lot of information in all aspects. Through this paper the author aims to measure and analyze the economic performance of SMEs operating in Albania. To achieve this objective, official data on business statistics published by national the statistical office (INSTAT) are used for two years period 2014-2015. In addition using an international framework addressed to the objective “improve the techniques for SMEs productivity measurement”, for the first time, a set of comparative performance indicators is established and in doing so, those results can be used as term of reference in future research activities in SMEs sector. From the results it came out that although the positive growth rate of GDP during the last years , the performance indicators of SMEs show a slightly negative trend, indicating indirectly the need for support, in order to empower their contribution in national economy.

scholarly journals Local Anesthetics and Recurrence after Cancer Surgery-What’s New? A Narrative Review

2021 ◽  
Vol 10 (4) ◽  
pp. 719
Author(s):  
Sarah D. Müller ◽  
Jonathan S. H. Ziegler ◽  
Tobias Piegeler
Keyword(s):  
Tumor Cells ◽  
Circulating Tumor Cells ◽  
Local Anesthetics ◽  
Experimental Studies ◽  
Perioperative Period ◽  
Cancer Surgery ◽  
Narrative Review ◽  
Future Research ◽  
Inflammatory Stress ◽  
Research Activities

The perioperative use of regional anesthesia and local anesthetics is part of almost every anesthesiologist’s daily clinical practice. Retrospective analyses and results from experimental studies pointed towards a potential beneficial effect of the local anesthetics regarding outcome—i.e., overall and/or recurrence-free survival—in patients undergoing cancer surgery. The perioperative period, where the anesthesiologist is responsible for the patients, might be crucial for the further course of the disease, as circulating tumor cells (shed from the primary tumor into the patient’s bloodstream) might form new micro-metastases independent of complete tumor removal. Due to their strong anti-inflammatory properties, local anesthetics might have a certain impact on these circulating tumor cells, either via direct or indirect measures, for example via blunting the inflammatory stress response as induced by the surgical stimulus. This narrative review highlights the foundation of these principles, features recent experimental and clinical data and provides an outlook regarding current and potential future research activities.

Modeling of Piezo-Actuated Stick-Slip Micro-Drives: An Overview

2012 ◽  
Vol 81 ◽  
pp. 39-48 ◽  
Author(s):  
Ha Xuan Nguyen ◽  
Christoph Edeler ◽  
Sergej Fatikow
Keyword(s):  
Mechanical Model ◽  
Integrated Model ◽  
Friction Model ◽  
Fundamental Importance ◽  
Future Research ◽  
Stick Slip ◽  
Research Activities ◽  
Model Combining ◽  
Friction Models

This paper gives an overview about problems of modeling of piezo-actuated stick-slip micro-drives. It has been found that existing prototypes of such devices have been investigated empirically. There is only few research dealing with the theory behind this kind of drives. By analyzing the current research activities in this field, it is believed that the model of the drive depends strongly on the friction models, but in most cases neglecting any influences of the guilding system.These analyses are of fundamental importance for an integrated model combining friction model and mechanical model offering promising possibilities for future research.

scholarly journals Spin–orbit-coupled fermions in an optical lattice clock

Nature ◽  
2016 ◽  
Vol 542 (7639) ◽  
pp. 66-70 ◽  
Author(s):  
S. Kolkowitz ◽  
S. L. Bromley ◽  
T. Bothwell ◽  
M. L. Wall ◽  
G. E. Marti ◽  
...  
Keyword(s):  
Optical Lattice ◽  
Spin Orbit ◽  
Optical Lattice Clock

Digital competences of the workforce – a research topic?

2017 ◽  
Vol 23 (3) ◽  
pp. 721-734 ◽  
Author(s):  
Matthias Murawski ◽  
Markus Bick
Keyword(s):  
Research Topic ◽  
Future Research ◽  
Digital Competence ◽  
Content Type ◽  
Research Activities ◽  
Starting Point ◽  
Pros And Cons ◽  
Definition Of ◽  
The Individual ◽  
Practical Implications

Purpose Considering working in the digital age, questions on the consequences for the individual workers are, so far, often neglected. The purpose of this paper is to deal with the question of whether the digital competences of the workforce is a research topic. The authors argue for the thesis that it is indeed a research topic. Design/methodology/approach In addition to a literature analysis of the top IS, HR, and learning publications, non-scientific sources, as well as the opinions of the authors, are included. The authors’ thesis is challenged through a debate of corresponding pros and cons. Findings The definition of digital competences lacks scientific depth. Focussing on the workforce is valid, as a “lifelong” perspective is not mandatory for research. Digital competence research is a multidisciplinary task to which the IS field can make a valuable contribution. Research limitations/implications Although relevant references are included, some aspects are mainly driven by the opinions of the authors. The theoretical implications encompass a call for a scientific definition of digital competences. Furthermore, scholars should focus on the competences of the workforce, including occupations, roles, or industries. The authors conclude by providing a first proposal of a research agenda. Practical implications The practical implications include the alignment of multiple stakeholders for the design of “digital” curricula and the integration by HR departments of the construct of digital competences, e.g. for compensation matters and job requirements. Originality/value This paper is one of very few contributions in the area of the digital competences of the workforce, and it presents a starting point for future research activities.

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