scholarly journals Ferrielectricity in DyMn2O5: A golden touchstone for multiferroicity of RMn2O5 family

2015 ◽  
Vol 05 (02) ◽  
pp. 1530003 ◽  
Author(s):  
J.-M. Liu ◽  
S. Dong
Keyword(s):  
Spin Structure ◽  
Structural Model ◽  
State Of The Art ◽  
Electric Polarization ◽  
Experimental Check ◽  
Spin Frustration ◽  
Temperature Dependent ◽  
The Past ◽  
Almost All ◽  
External Stimuli

The RMn 2 O 5 manganite compounds represent one class of multiferroic family with magnetic origins, which has been receiving continuous attention in the past decade. So far, our understanding of the magnetic origins for ferroelectricity in RMn 2 O 5 is associated with the nearly collinear antiferromagnetic structure of Mn ions, while the exchange striction induced ionic displacements are the consequence of the spin frustration competitions. While this scenario may be applied to almost all RMn 2 O 5 members, its limitation is either clear: the temperature-dependent behaviors of electric polarization and its responses to external stimuli are seriously materials dependent. These inconsistences raise substantial concern with the state-of-the-art physics of ferroelectricity in RMn 2 O 5. In this mini-review, we present our recent experimental results on the roles of the 4f moments from R ions which are intimately coupled with the 3d moments from Mn ions. DyMn 2 O 5 is a golden figure for illustrating these roles. It is demonstrated that the spin structure accommodates two nearly collinear sublattices which generate respectively two ferroelectric (FE) sublattices, enabling DyMn 2 O 5 an emergent ferrielectric (FIE) system rarely identified in magnetically induced FEs. The evidence is presented from several aspects, including FIE-like phenomena and magnetoelectric responses, proposed structural model, and experimental check by nonmagnetic substitutions of the 3d and 4f moments. Additional perspectives regarding possible challenges in understanding the multiferroicity of RMn 2 O 5 as a generalized scenario are discussed.

The State of the Art in Management Education Applicable to Aerospace Activities

1967 ◽  
Vol 71 (677) ◽  
pp. 342-343
Author(s):  
F. H. East
Keyword(s):  
Research And Development ◽  
Management Education ◽  
State Of The Art ◽  
Development Project ◽  
The State ◽  
The Other ◽  
The Past ◽  
Defence Budget ◽  
The One ◽  
Almost All

The Aviation Group of the Ministry of Technology (formerly the Ministry of Aviation) is responsible for spending a large part of the country's defence budget, both in research and development on the one hand and production or procurement on the other. In addition, it has responsibilities in many non-defence fields, mainly, but not exclusively, in aerospace.Few developments have been carried out entirely within the Ministry's own Establishments; almost all have required continuous co-operation between the Ministry and Industry. In the past the methods of management and collaboration and the relative responsibilities of the Ministry and Industry have varied with time, with the type of equipment to be developed, with the size of the development project and so on. But over the past ten years there has been a growing awareness of the need to put some system into the complex business of translating a requirement into a specification and a specification into a product within reasonable bounds of time and cost.

Digital Microscopy Imaging in Drug Discovery and Development

2001 ◽  
Vol 7 (S2) ◽  
pp. 622-623
Author(s):  
Xiaoyou Ying ◽  
Jean Sprinkle Cavallo ◽  
Bruce McCullough
Keyword(s):  
Drug Discovery ◽  
State Of The Art ◽  
Biological Research ◽  
Digital Microscopy ◽  
Microscopy Imaging ◽  
Bioimage Informatics ◽  
Drug Discovery And Development ◽  
Subcellular Organelles ◽  
The Past ◽  
Almost All

Digital microscopy, the integration of digital and microscopy technologies, was initiated for quantitative microscopic image analysis, but it is now for almost all microscopy applications. During the past decade, with the advance of digital technologies, digital microscopy imaging is becoming an indispensable technology in drug discovery.We started establishing state-of-the-art digital microscopy imaging for drug discovery with the investigation of bioimaging applications at our US research site. Our results shown that all the top 5 bioimaging needs require computer-aided microscopy. Based on this investigation and our review of the microscopy imaging applications in the pharmaceutical industry, we determined four directions for microscopy in drug discovery: multidimensional/multimodal microscopy, digitalization, automation, and bioimage informatics.Multidimensional/multimodal microscopy imaging is required by the nature of biological research, which is fundamental in drug discovery. From genomic imaging to pathology observation, we require biological details and compound activities at the levels from subcellular organelles to organ tissues, from cellular signaling to anatomical locations of compounds.

A Macintosh Interface for the Cameca Camebax-Micro Electron Microprobe

1990 ◽  
Vol 48 (1) ◽  
pp. 438-439
Author(s):  
Carl E. Henderson
Keyword(s):  
Electron Microprobe ◽  
Processing Speed ◽  
Word Processing ◽  
State Of The Art ◽  
Computer Control ◽  
Third Party ◽  
Disk Storage ◽  
The Past ◽  
User Facility ◽  
Instrument Control

Over the past few years it has become apparent in our multi-user facility that the computer system and software supplied in 1985 with our CAMECA CAMEBAX-MICRO electron microprobe analyzer has the greatest potential for improvement and updating of any component of the instrument. While the standard CAMECA software running on a DEC PDP-11/23+ computer under the RSX-11M operating system can perform almost any task required of the instrument, the commands are not always intuitive and can be difficult to remember for the casual user (of which our laboratory has many). Given the widespread and growing use of other microcomputers (such as PC’s and Macintoshes) by users of the microprobe, the PDP has become the “oddball” and has also fallen behind the state-of-the-art in terms of processing speed and disk storage capabilities. Upgrade paths within products available from DEC are considered to be too expensive for the benefits received. After using a Macintosh for other tasks in the laboratory, such as instrument use and billing records, word processing, and graphics display, its unique and “friendly” user interface suggested an easier-to-use system for computer control of the electron microprobe automation. Specifically a Macintosh IIx was chosen for its capacity for third-party add-on cards used in instrument control.

BP Global Energy Outlook 2030

2013 ◽  
pp. 109-128 ◽  
Author(s):  
C. Rühl
Keyword(s):  
Emerging Economies ◽  
Energy Demand ◽  
Fossil Fuels ◽  
Net Energy ◽  
Global Energy ◽  
The Past ◽  
Market Shares ◽  
The Us ◽  
Almost All ◽  
Oil Gas

This paper presents the highlights of the third annual edition of the BP Energy Outlook, which sets out BP’s view of the most likely developments in global energy markets to 2030, based on up-to-date analysis and taking into account developments of the past year. The Outlook’s overall expectation for growth in global energy demand is to be 36% higher in 2030 than in 2011 and almost all the growth coming from emerging economies. It also reflects shifting expectations of the pattern of supply, with unconventional sources — shale gas and tight oil together with heavy oil and biofuels — playing an increasingly important role and, in particular, transforming the energy balance of the US. While the fuel mix is evolving, fossil fuels will continue to be dominant. Oil, gas and coal are expected to converge on market shares of around 26—28% each by 2030, and non-fossil fuels — nuclear, hydro and renewables — on a share of around 6—7% each. By 2030, increasing production and moderating demand will result in the US being 99% self-sufficient in net energy. Meanwhile, with continuing steep economic growth, major emerging economies such as China and India will become increasingly reliant on energy imports. These shifts will have major impacts on trade balances.

Temperature-Dependent Die Warpage Measurements Up to 400°C

2017 ◽  
Author(s):  
Tobias Mittereder ◽  
Bernhard Ferstl ◽  
Terry Heidmann ◽  
Christian Hollerith
Keyword(s):  
Data Acquisition ◽  
White Light ◽  
State Of The Art ◽  
Thermomechanical Behavior ◽  
Temperature Dependent ◽  
Optical Access

Abstract Temperature-dependent die warpage measurements show the possibility to analyze the thermomechanical behavior during assembly, e.g. within soldering processes. The warpage data acquisition is realized by confocal chromatic white light profilometry in combination with a precision heating/cooling chuck encapsulated in a chamber with optical access. The combination of these two tools allows precise die warpage evaluation under varied device temperature up to +400°C. This method helps to solve emerging challenges due to warpage during assembly of state of the art packages including thin dies and stacked dies as in e.g. 3D-SIPs.

Building Research Teams

2017 ◽  
Author(s):  
Ken Peach
Keyword(s):  
Common Goal ◽  
Research Teams ◽  
Building Research ◽  
The Past ◽  
Collective Activity ◽  
Research Administrators ◽  
Working Together ◽  
Common Goals ◽  
Almost All ◽  
Century Science

This chapter discusses the process of building research teams. Increasingly over the past three-quarters of a century, science has become a collective activity, with teams of tens, hundreds or even thousands of scientists, engineers and technicians working together on a common goal. Consequently, almost all research involves building, motivating and maintaining a research team. Even a theoretical group is likely to have one or two postdocs, graduate students and visitors, but research teams will, in addition, have engineers and technicians, as well as, possibly, research administrators. The chapter also addresses the importance of creating and maintaining a good team and team spirit, as large projects are assembled from a large number of small teams working on common goals, usually in a loose federated structure with some overall coordination and leadership.

Impact of risk aversion, reactance proneness and risk appraisal on travel destination risk perception

2021 ◽  
pp. 135676672098786
Author(s):  
Melvin Prince ◽  
Young Kim
Keyword(s):  
Risk Perception ◽  
Risk Aversion ◽  
Risk Perceptions ◽  
Structural Model ◽  
International Travel ◽  
Kuala Lumpur ◽  
Risk Appraisal ◽  
Travel Destination ◽  
The Past ◽  
Subjective Estimates

The aim of the study is to investigate the motivational effects of tourist traits and risk appraisal on tourist destination risk perception. Risk appraisal involves subjective estimates of vulnerability to a threat and the threat’s consequential severity. Fear levels influence both of these elements of risk appraisal. Individual differences in reactance proneness and risk aversion are introduced into the study model to more fully account for differences in travel destination risk perceptions. The study design involves US adults, who have used their passports for international travel in the past 5 years. Travel risk assessments were studied for four destination sites: London, Tokyo, Kuala Lumpur and Istanbul. A general structural model is developed to test hypotheses about antecedents and consequents of risk appraisal and destination risk perception.

scholarly journals Improved PrEP Awareness and Use among Trans Women in San Francisco, California

2021 ◽  
Author(s):  
Erin C. Wilson ◽  
Christopher J. Hernandez ◽  
Susan Scheer ◽  
Dillon Trujillo ◽  
Sean Arayasirikul ◽  
...  
Keyword(s):  
San Francisco ◽  
Anal Intercourse ◽  
Receptive Anal Intercourse ◽  
The Past ◽  
National Hiv Behavioral Surveillance ◽  
Trans Women ◽  
Gender Based ◽  
Prep Awareness ◽  
Almost All ◽  
Exposure Prophylaxis

AbstractTransgender women face a serious risk of HIV infection. Despite this, there is limited knowledge and use of Pre-exposure prophylaxis (PrEP). We measured the continuity of prevention across services in the PrEP cascade and correlates of PrEP use among trans women in San Francisco enrolled in the 2019/20 National HIV Behavioral Surveillance Study. Knowledge and use of PrEP among trans women in San Francisco increased in recent years; almost all (94.0%) had heard about PrEP, 64.7% had discussed PrEP with a healthcare provider, and 44.8% had taken PrEP in the past 12 months. PrEP use was associated with participation in a PrEP demonstration project (aOR = 31.44, p = 0.001) and condomless receptive anal intercourse (aOR = 3.63, p = 0.024). Injection drug use was negatively associated (aOR = 0.19, p = 0.014). Efforts are needed to combat the gender-based stigma and discrimination faced by trans women, which can result in avoidance and mistrust of the medical system.

scholarly journals Linear Response of General Observables in Spiking Neuronal Network Models

Entropy ◽  
2021 ◽  
Vol 23 (2) ◽  
pp. 155
Author(s):  
Bruno Cessac ◽  
Ignacio Ampuero ◽  
Rodrigo Cofré
Keyword(s):  
Linear Response ◽  
Network Connectivity ◽  
Network Models ◽  
General Context ◽  
Collective Effect ◽  
Neuronal Dynamics ◽  
The Past ◽  
Spatio Temporal ◽  
External Stimuli ◽  
Spike Dynamics

We establish a general linear response relation for spiking neuronal networks, based on chains with unbounded memory. This relation allow us to predict the influence of a weak amplitude time dependent external stimuli on spatio-temporal spike correlations, from the spontaneous statistics (without stimulus) in a general context where the memory in spike dynamics can extend arbitrarily far in the past. Using this approach, we show how the linear response is explicitly related to the collective effect of the stimuli, intrinsic neuronal dynamics, and network connectivity on spike train statistics. We illustrate our results with numerical simulations performed over a discrete time integrate and fire model.

scholarly journals Molecular and Cellular Mechanisms Underlying Temperature-Dependent Sex Determination in Turtles

2021 ◽  
pp. 1-9
Author(s):  
Horacio Merchant-Larios ◽  
Verónica Díaz-Hernández ◽  
Diego Cortez
Keyword(s):  
Animal Models ◽  
Sex Determination ◽  
Incubation Temperature ◽  
State Of The Art ◽  
Current Understanding ◽  
Temperature Dependent ◽  
Cellular Mechanisms ◽  
Male Phenotype ◽  
History Of ◽  
Reptilian Species

The discovery in mammals that fetal testes are required in order to develop the male phenotype inspired research efforts to elucidate the mechanisms underlying gonadal sex determination and differentiation in vertebrates. A pioneer work in 1966 that demonstrated the influence of incubation temperature on sexual phenotype in some reptilian species triggered great interest in the environment’s role as a modulator of plasticity in sex determination. Several chelonian species have been used as animal models to test hypotheses concerning the mechanisms involved in temperature-dependent sex determination (TSD). This brief review intends to outline the history of scientific efforts that corroborate our current understanding of the state-of-the-art in TSD using chelonian species as a reference.

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