168 research outputs found
CAMMUAZA, or the ceremony used at the Induction of a Birman into the Order of Priesthood, called Phonghi, or Rhahaan (1795) by Michael Symes, edited by Michael W. Charney
This account of the induction ceremony for Buddhist monks was included as Appendix V in Michael Symes, An Acount of an Embassy to the Kingdom of Ava, Sent by the Governor-General of India in the Year 1795 (London: W. Bulmer & Co., 496-500). Symes, then a major in the 76th Regiment, made numerous valuable observations on Burmese culture, society, government, and history. While it is clear that he did consult the accounts of other visitors to Burma, most of his material was derived from first-hand observation or from material provided by Burmese acquaintances, and the following account was likely derived from the latter
An Account of an Embassy to the Kingdom of Ava, Sent by the Governor-General of India, in the Year 1795 by Michael Symes, edited by Michael W. Charney
Recent progress towards the electrosynthesis of ammonia from sustainable resources
Ammonia (NH3) is a key commodity chemical of vital importance for fertilisers. It is made on an industrial scale via the Haber Bosch process, which requires significant infrastructure to be in place such that ammonia is generally made in large, centralized facilities. If ammonia could be produced under less demanding conditions, then there would be the potential for smaller devices to be used to generate ammonia in a decentralized manner for local consumption. Electrochemistry has been proposed as an enabling technology for this purpose as it is relatively simple to scale electrolytic devices to meet almost any level of demand. Moreover, it is possible to envisage electrosynthetic cells where water could be oxidised to produce protons and electrons at the anode which could then be used to reduce and protonate nitrogen to give ammonia at the cathode. If this nitrogen were sourced from the air, then the only required infrastructure for this process would be supplies of water, air and electricity, the latter of which could be provided by renewables. Hence an electrosynthetic cell for ammonia production could allow NH3 to be generated sustainably in small, low-cost devices requiring only minimal facilities. In this review, we describe recent progress towards such electrosynthetic ammonia production devices, summarizing also some of the seminal literature in the field. Comparison is made between the various different approaches that have been taken, and the key remaining challenges in the electrosynthesis of ammonia are highlighted
THE COUPLING OF PERCEPTION AND ACTION IN REPRESENTATION
This thesis examines how the objects that we visually perceive in the world are coupled to
the actions that we make towards them. For example, a whole hand grasp might be coupled
with an object like an apple, but not with an object like a pea. It has been claimed that the
coupling of what we see and what we do is not simply associative, but is fundamental to
the way the brain represents visual objects. More than association, it is thought that when
an object is seen (even if there is no intention to interact with it), there is a partial and
automatic activation of the networks in the brain that plan actions (such as reaches and
grasps). The central aim of this thesis was to investigate how specific these partial action
plans might be, and how specific the properties of objects that automatically activate them
might be. In acknowledging that perception and action are dynamically intertwining
processes (such that in catching a butterfly the eye and the hand cooperate with a fluid and
seamless efficiency), it was supposed that these couplings of perception and action in the
brain might be loosely constrained. That is, they should not be rigidly prescribed (such that
a highly specific action is always and only coupled with a specific object property) but
they should instead involve fairly general components of actions that can adapt to different
situations. The experimental work examined the automatic coupling of simplistic left and
right actions (e.g. key presses) to pictures of oriented objects. Typically a picture of an
object was shown and the viewer responded as fast as possible to some object property that
was not associated with action (such as its colour). Of interest was how the performance of
these left or right responses related to the task irrelevant left or right orientation of the
object. The coupling of a particular response to a particular orientation could be
demonstrated by the response performance (speed and accuracy). The more tightly coupled
a response was to a particular object orientation, the faster and more accurate it was. The
results supported the idea of loosely constrained action plans. Thus it appeared that a range
of different actions (even foot responses) could be coupled with an object's orientation.
These actions were coupled by default to an object's X-Z orientation (e.g. orientation in the
depth plane). In further reflecting a loosely constrained perception-action mechanism,
these couplings were shown to change in different situations (e.g. when the object moved
towards the viewer, or when a key press made the object move in a predictable way). It
was concluded that the kinds of components of actions that are automatically activated
when viewing an object are not very detailed or fixed, but are initially quite general and
can change and become more specific when circumstances demand it
A re-evaluation of Sn(II) phthalocyanine as a catalyst for the electrosynthesis of ammonia
The electrosynthesis of ammonia from nitrogen and water is a topic of considerable interest in the quest for sustainable and decentralized NH3 production. Tin(II) phthalocyanine complexes have been proposed as electrocatalysts for nitrogen reduction to ammonia in aqueous solution, with Faradaic yields approaching 2% having been reported. Herein, however, we show that such complexes are not electrocatalysts for this transformation, with the amount of ammonia detected being essentially the same under N2 and under Ar. Instead, we suggest that apparent ammonia generation could arise either through contaminants in the as-prepared tin (II) phthalocyanine complexes, or by the electro-decomposition of these complexes under cathodic bias
Towards a Better Understanding of the Electrochemical Synthesis of 2,5-dicarboxy-2,5-dihydrofurans: Structure, Mechanism and Influence over Stereochemistry
2,5-Dicarboxy-2,5-dihydrofurans are key constituents of a number of natural products and have roles as intermediates in the formation of other such compounds of interest. Typically, these species are synthesised using Pb(IV) salts. Electrochemical syntheses of 2,5-diacetoxy-2,5-dihydrofuran that do not require the use of lead have been reported, but hitherto most of these studies have lacked sufficient experimental detail for this procedure to be more widely adopted. Moreover, no electrochemical study has yet reported the ratio of cis and trans isomers produced. Herein, we compare the chemical, lead-based route to 2,5-diacetoxy-2,5-dihydrofuran with a fully-described electrochemical synthesis method. In doing so, we have discovered that the cis and trans isomers of this compound were previously incorrectly assigned in the literature, an error that we correct by obtaining the crystal structure of cis-2,5-diacetoxy-2,5-dihydrofuran. This allows the ratios of the isomers as prepared by the chemical (2:1 cis:trans) and electrochemical (7:5 cis:trans) methods to be obtained. Through experimental and computational insights, we propose a mechanism for the electrochemical synthesis of 2,5-dicarboxy-2,5-dihydrofurans and go some way towards validating this mechanism by synthesising 2,5-dibutoxy-2,5-dihydrofuran electrochemically for the first time. We hope that these findings will provide some greater clarity to the literature surrounding the electrosynthesis and potential applications of 2,5-dicarboxy-2,5-dihydrofurans
Towards a better understanding of the electrosynthesis of 2,5-dicarboxy-2,5-dihydrofurans: structure, mechanism and influence over stereochemistry
2,5-Dicarboxy-2,5-dihydrofurans are key constituents of a number of natural products and have roles as intermediates in the formation of other such compounds of interest. Typically, these species are synthesized using toxic Pb(IV) salts. Electrochemical syntheses of 2,5-diacetoxy-2,5-dihydrofuran that do not require the use of lead have been reported, but a general lack of experimental detail has prevented these procedures from being more widely adopted. Moreover, no electrochemical study has yet reported the ratio of cis and trans isomers produced. Herein, we compare the chemical, lead-based route to 2,5-diacetoxy-2,5-dihydrofuran with a fully described electrosynthesis method. In doing so, we have discovered that the cis and trans isomers of this compound were previously incorrectly assigned in the literature, an error that we correct by obtaining the crystal structure of cis-2,5-diacetoxy-2,5-dihydrofuran. This allows the ratios of the isomers as prepared by the chemical (2 : 1 cis : trans) and electrochemical (7 : 5 cis : trans) methods to be obtained. Through experimental and computational insights, we propose a mechanism for the electrochemical synthesis of 2,5-dicarboxy-2,5-dihydrofurans and go some way towards validating this mechanism by synthesizing 2,5-dibutoxy-2,5-dihydrofuran electrochemically for the first time. We hope that these findings will provide some greater clarity to the literature surrounding the electrosynthesis and potential applications of 2,5-dicarboxy-2,5-dihydrofurans
Assessing the cost of global biodiversity and conservation knowledge
Knowledge products comprise assessments of authoritative information supported by stan-dards, governance, quality control, data, tools, and capacity building mechanisms. Considerable resources are dedicated to developing and maintaining knowledge productsfor biodiversity conservation, and they are widely used to inform policy and advise decisionmakers and practitioners. However, the financial cost of delivering this information is largelyundocumented. We evaluated the costs and funding sources for developing and maintain-ing four global biodiversity and conservation knowledge products: The IUCN Red List ofThreatened Species, the IUCN Red List of Ecosystems, Protected Planet, and the WorldDatabase of Key Biodiversity Areas. These are secondary data sets, built on primary datacollected by extensive networks of expert contributors worldwide. We estimate that US116–204 million), plus 293 person-years of volunteer time (range: 278–308 person-years) valued at US12–16 million), were invested inthese four knowledge products between 1979 and 2013. More than half of this financingwas provided through philanthropy, and nearly three-quarters was spent on personnelcosts. The estimated annual cost of maintaining data and platforms for three of these knowl-edge products (excluding the IUCN Red List of Ecosystems for which annual costs were notpossible to estimate for 2013) is US6.2–6.7 million). We esti-mated that an additional US12 million. These costs are much lower than those tomaintain many other, similarly important, global knowledge products. Ensuring that biodi-versity and conservation knowledge products are sufficiently up to date, comprehensiveand accurate is fundamental to inform decision-making for biodiversity conservation andsustainable development. Thus, the development and implementation of plans for sustain-able long-term financing for them is critical
High-resolution μCT of a mouse embryo using a compact laser-driven X-ray betatron source
High-resolution microcomputed tomography with benchtop X-ray sources requires long scan times because of the heat load limitation on the anode. We present an alternative, high-brightness plasma-based X-ray source that does not suffer from this restriction. A demonstration of tomography of a centimeter-scale complex organism achieves equivalent quality to a commercial scanner. We will soon be able to record such scans in minutes, rather than the hours required by conventional X-ray tubes
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