Quantum diffusion in solid H2: a short review

1987 ◽  
Vol 65 (11) ◽  
pp. 1453-1462 ◽  
Author(s):  
H. Meyer

A review is presented on the experimental observations and the theoretical progress made in investigating the quantum diffusion in solid H2. The mechanisms of resonant ortho–para conversion and of quantum tunneling are discussed. It is pointed out that the ortho-H2 clustering reaction process, by which quantum diffusion is detected, needs to be better understood to account for the dependence of the observed reaction-time constant τ on temperature and on ortho-H2 concentration. The general trends in the experimental results are reviewed, and the discrepancies between various determinations of τ are discussed. Further experiments are suggested as well as computer simulations for the clustering procedure. A review is also given on the status of quantum diffusion of HD in solid H2. Recent observations on recombination rates of H and on depolarization rates of muons in H2 that show evidence of quantum effects are briefly mentioned.

Author(s):  
Chris Armstrong

The status quo within international politics is that individual nation-states enjoy extensive and for the most part exclusive rights over the resources falling within their borders. Egalitarians have often assumed that such a situation cannot be defended, but perhaps some sophisticated defences of state or national rights over natural resources which have been made in recent years prove otherwise. This chapter critically assesses these various arguments, and shows that they are not sufficient to justify the institution of ‘permanent sovereignty’ over resources. Even insofar as those arguments have some weight, they are compatible with a significant dispersal of resource rights away from individual nation-states, both downwards towards local communities, and upwards towards transnational and global agencies.


Author(s):  
Paul Humphreys

Paul Humphreys pioneered philosophical investigations into the methodological revolution begun by computer simulations. He has also made important contributions to the contemporary literature on emergence by developing the fusion account of diachronic emergence and its generalization, transformational emergence. He is the discoverer of what has come to be called “Humphreys” Paradox in probability theory and has also made influential contributions to the literature on probabilistic causality and scientific explanation. This collection contains fourteen of his previously published papers on topics ranging from numerical experiments to the status of scientific metaphysics. There is also and a previously unpublished paper on social dynamics. The volume is divided into four parts on, respectively, computational science, emergence, probability, and general philosophy of science. The first part contains the seminal 1990 paper on computer simulations, with three other papers arguing that these new methods cannot be accounted for by traditional methodological approaches. The second part contains the original presentation of fusion emergence and three companion papers arguing for diachronic approaches to the topic, rather than the then dominant synchronic accounts. The third part starts with the paper that introduced the probabilistic paradox followed by a later evaluation of attempts to solve it. A third paper argues, contra Quine, that probability theory is a purely mathematical theory. The final part includes papers on causation, explanation, metaphysics, and an agent-based model that shows how endogenous uncertainty undermines utility maximization. Each of the four parts is followed by a comprehensive postscript with retrospective assessments.


2021 ◽  
pp. 1-4
Author(s):  
Anders Björklund

In two recent postmortem studies, Jeffrey Kordower and colleagues report new findings that open up for an interesting discussion on the status of GDNF/NRTN signaling in patients with Parkinson’s disease (PD), adding an interesting perspective on the, admittedly very limited, signs of restorative effects previously seen in GDNF/NRTN-treated patients. Their new findings show that the level of the GDNF signaling receptor Ret is overall reduced by about 65% relative to non-PD controls, and most severely, up to 80%, in nigral neurons containing α-synuclein inclusions, accompanied by impaired signaling downstream of the Ret receptor. Notably, however, the vast majority of the remaining nigral neurons retained a low level of Ret expression, and hence a threshold level of signaling. Further observations made in two patients who had received AAV-NRTN gene therapy 8–10 years earlier suggest the intriguing possibility that NRTN is able to restore Ret expression and upregulate its own signaling pathway. This “wind-up” mechanism, which is likely to depend on an interaction with dopaminergic transcription factor Nurr1, has therapeutic potential and should encourage renewed efforts to turn GDNF/NRTN therapy into success, once the recurring problem of under-dosing is resolved.


2014 ◽  
Vol 31 (4) ◽  
pp. 10-13 ◽  
Author(s):  
Sharon Q. Yang

Purpose – This study aims to ascertain the trends and changes of how academic libraries market and deliver information literacy (IL) on the web. Design/methodology/approach – The author compares the findings from two separate studies that scanned the Web sites for IL-related activities in 2009 and 2012, respectively. Findings – Academic libraries intensified their efforts to promote and deliver IL on the web between 2009 and 2012. There was a significant increase in IL-related activities on the web in the three-year period. Practical implications – The findings describe the status quo and changes in IL-related activities on the libraries’ Web sites. This information may help librarians to know what they have been doing and if there is space for improvement. Originality/value – This is the only study that spans three years in measuring the progress librarians made in marketing and delivering IL on the Web.


1993 ◽  
Vol 02 (03) ◽  
pp. 507-546 ◽  
Author(s):  
M.K. MOE

Substantial progress has been made in double beta decay experiments in the past few years, including the beginning of sensitive new searches for neutrinoless double beta decay, and several additional positive detections of the two-neutrino mode by geochemical, radiochemical, and direct-counting techniques. This review discusses the recent experimental activity.


F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2790
Author(s):  
William D. Pearse

Despite the progress that has been made in the visualisation of information since Haeckel's time, phylogenetic visualisation has moved forward remarkably little. In this brief essay, I give a short review of what I consider to be some recent major advances, and outline a new kind of phylogenetic visualisation. This new graphic, the fibre plot, uses the metaphor of sections through a tree to describe change in a phylogeny. As an animation, I suggest it is a powerful method to help interpret large phylogenetic hypotheses, although snapshots of it can also be displayed. As we enter the Anthropocene, I argue there has never been a greater need to know humanity's true place in the world, as depicted in the tree of life.


2020 ◽  
Vol 10 (3) ◽  
Author(s):  
Denys Kutsenko

The article deals with an instrumental use of the national legislation by the local authorities in Kharkiv, the second-largest city in Ukraine and shows how the shortcomings in the national legislation on the politics of memory can be used by the local political elites of “borderland city” in an attempt to raise the rating and/or to mobilize the electorate before the elections. Consequently, several interviews with local experts and activists were conducted in 2019, and qualitative data analysis was made for the transcribed texts as well as a short review of other papers on the subject. Also, the article shows how the local court can accelerate the process of depriving a historical building of the status of an architectural monument using decommunization laws. The study confirms the existence of serious polarization in Ukrainian society and the superficial nature of decommunization (started in 2015), which stimulates the deepening of such polarization.


2017 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
LESTARI NINGRUM

Aviation business is a capital intensive and high risk in terms of safety. Legislation in force in Indonesia requires enterprises should cost in the form of a limited liability company that is obliged to deposit the basic capital of 500 billion rupiah. The capital cannot be made in working capital which is useful for the collateral to a third party. The regulations for a limited liability company are to be established by at least 2 people. The purpose of this research is to analyze the linkage of the board directors and the status of aviation industry licensing law. The position of the legal status of business entities where shareholder is only one person is to be studied in this descriptive study. The result shows that the airlines company should provide the capital risk and high insurance of the third party. UUPT also has given the authority of the shareholders (who owns 20 % of the share) to be decision makers in the company. However, without independent surveillance, it is possible that the shareholders do some mistakes in making decisions. Some mistakes are related to the policy, the using of authorized capital, and others. Aviation business is a capital intensive and high risk in terms of safety. Legislation in force in Indonesia requires enterprises should cost in the form of a limited liability company that is obliged to deposit the basic capital of 500 billion rupiah. The capital cannot be made in working capital which is useful for the collateral to a third party. The regulations for a limited liability company are to be established by at least 2 people. The position of the legal status of business entities where shareholder is only one person is to be studied in this descriptive study.


2013 ◽  
Vol 15 (1) ◽  
pp. 189 ◽  
Author(s):  
M. VACCHI ◽  
M. MONTEFALCONE ◽  
V. PARRAVICINI ◽  
A. ROVERE ◽  
P. VASSALLO ◽  
...  

Spatial modelling is an emerging approach to the management of coastal marine habitats, as it helps understanding and predicting the results of global change. This paper reviews critically two recent examples developed in Liguria, an administrative region of NW Italy. The first example, aiming at predicting habitat status depending on pressures, provides managers with the opportunity of envisaging different scenarios for the consequences of coastal development choices. The second example defines the status of an important Mediterranean coastal marine habitat (Posidonia oceanica meadows) under natural conditions, allowing for quantifying human impacts on regressed meadows. Both modelling approaches are useful to define the targets of coastal management, and may help choosing the best management option. Well-planned and sustained monitoring is essential to model validation and improvement.


2020 ◽  
Vol 3 (1) ◽  
pp. 85-105
Author(s):  
Indah Parmitasari

This article seeks to discuss the authentication of financing contracts in Islamic banking in the use of lafadz basmallah. The problem discussed is how to authenticate the financing contract deed in Islamic banking in the use of lafadz basmallah. Every financing activity in Islamic banking is made in a contract, to get certainty and strength of perfect proof, the bank wants the contract to be made in an authentic deed. An authentic deed is a deed made by or in the presence of an authorized official for that purpose is made according to the provisions of the law. Notary as the official in charge of making the deed is guided by Article 38 of the Notary Position Law. A deed must fulfill the provisions of Article 1868 of the Civil Code, which is made by and or before an authorized official, and made a public official who has the authority. The notary is authorized as long as the certificate, person, place and time of the deed are made. This article concludes that the financing contract deed in Islamic banking that contains lafadz basmallah at the beginning of the deed does not meet the requirements of Article 1868 of the Civil Code, because it violates the provisions of Article 38 of the Notary Position Law so that the status of the act is degraded into a deed under the hand. Abstrak Artikel ini membahas tentang autentikasi akad pembiayaan pada perbankan syariah dalam penggunaan lafadz basmallah. Permasalahan yang dibahas adalah bagaimana keautentikan akta akad pembiayaan pada perbankan syariah dalam penggunaan lafadz basmallah. Setiap kegiatan pembiayaan dalam perbankan syariah dibuat dalam suatu akad, guna mendapatkan kepastian dan kekuatan pembuktian yang kuat, bank menghendaki akad dibuat dalam bentuk akta autentik. Akta autentik adalah akta yang dibuat oleh atau di hadapan pejabat yang berwenang untuk itu sesuai dengan ketentuan undang-undang. Notaris sebagai pejabat yang berwenang dalam membuat akta berpedoman pada Pasal 38 Undang-Undang Jabatan Notaris tentang bentuk akta. Suatu akta harus memenuhi ketentuan Pasal 1868 KUH Perdata, yaitu dibuat oleh dan atau di hadapan pejabat yang berwenang, dibuat menurut ketentuan undang-undang. Notaris berwenang sepanjang mengenai aktanya, orangnya, tempat dan waktunya akta dibuat. Artikel ini menyimpulkan bahwa akta akad pembiayaan pada perbankan syariah yang memuat lafadz basmallah pada awal akta kedudukannya bukan lagi sebagai akta autentik tetapi terdegradasi menjadi akta di bawah tangan, karena syarat otentisitas Pasal 1868 KUH Perdata tidak terpenuhi, yaitu syarat formalitas sesuai Pasal 38 Undang-Undang Jabatan Notaris Perubahan.


Sign in / Sign up

Export Citation Format

Share Document