High level of 3^3He polarization of 81\% Maintained in an on-beam 3^3He spin filter using SEOP

Maintaining high levels of 3He polarization over long periods of time is important to many areas of fundamental and particle beam physics. Long measurement times are often required in such experiments and the data quality is a function of the 3He polarization. This is the case for neutron scattering where the 3He can be used to analyze the spin of a scattered neutron beam and relatively small fluxes of polarized neutrons leads to experiment times longer than several days. Consequently the J\"ulich Centre for Neutron Science (JCNS) is developing spin-exchange optical pumping (SEOP) systems capable of polarizing the 3He gas in place on a typical neutron instrument. Using a polarizer device we constructed a high level of 3He polarization of 81 % \pm2% was maintained with good time stability. Such levels of polarization maintained over time will be able to reduce the measurement times for such experiments and eliminate time dependent data corrections.Comment: 4 pages 2 figure

The production of space and construction of frontier: Contesting a Cambodian resource landscape

This research employs Henry Lefebvre’s concept of “the production of space” and the notion of frontiers – empty or unused space – to explore the complex spatial contestations over resource landscapes in Cambodia. The study focuses on the construction of frontiers by examining how socio-spatial relations are produced in relation to how the frontier is constructed. In this research, two groups of actors and processes are involved: (1) the state and its associated elite actors/agencies who employ spatial representations (maps) to organise the landscape; and (2) the local actors who construct and organise space by directly living in it. Regarding the state-based spatial arrangements, this research employs critical cartography to examine formal boundaries made by the state and its associated agencies, including the political elites, conservation organisations and development agencies. In regard to informal local level spatial arrangements, place-making processes are examined to understand how land and resources are organised by local actors. The thesis focuses on one case study site located in Northwest Cardamom – an upland area of the western part of Cambodia near the border of Thailand and a former Khmer Rouge stronghold. This thesis argues that frontier – empty or wasteland – is not an absolute geographical space, but a produced space. Frontier construction is at the centre of land and resource conflicts over the landscape. This produced space is the outcome of dialectical relations of spatial idealisation, the representation of space and direct spatial interaction among different actors whose interests are to access and control the landscape. This research found that being able to use maps, the state and its associated elite actors and agencies are able to formally exclude local communities from accessing land and resources by making landscape appear empty or unused. The local spatial organisation and socio-spatial relations are also constructed within the notion of a frontier, which is the outcome of a traumatic political history and physical traits of the landscape. With the long-term experience of organising local landscapes, the ex-Khmer Rouge (ex-KR) tend to have more control over land and resources compared to new in-migrants moving to search for land. Two forms of interaction between state-based and local-based spatial representation and organisation can be observed. The first is state enforced abstract boundaries which directly exclude people from accessing land and resources. The second is state-based private land titling which delegitimises local villagers’ land claims

The analysis of tin diffusion steps in the preparation of Nb3Sn-Cu superconductors

A three stage heat transfer is employed to eliminate the tin ball-up problem. A void nucleation problem is encountered in stage I and it can be reduced by minimizing time at stage I. Therefore, T(,d), the tin depletion time, is important in order to minimize time at stage I. Experiments on stage I heat treatment in three geometrical conditions, planar, internal tin and external tin, are studied in order to determine T(,d) values. The depletion of tin layer is proportional to the square root of time for the planar and external tin cases. A finite-difference numerical analysis is applied to study these three geometrical conditions. The numerical model predicts T(,d) values slightly less than the experimental results. Possible causes of disagreement have been discussed. The results show that the planar geometry is the upper bound solution of the external tin wire condition and the internal tin wire condition is the lower bound solution of the external tin wire condition

Spin Relaxation Resonances Due to the Spin-Axis Interaction in Dense Rubidium and Cesium Vapor

Resonances in the magnetic decoupling curves for the spin relaxation of dense alkali-metal vapors prove that much of the relaxation is due to the spin-axis interaction in triplet dimers. Initial estimates of the spin-axis coupling coefficients for the dimers are 290 MHz for Rb; 2500 MHz for Cs.Comment: submitted to Physical Review Letters, text + 3 figure

Lon et al. Malaria Journal 2014, 13:96

Blackwater fever in an uncomplicated Plasmodium falciparum patient treated with dihydroartemisinin-piperaquin

Online Ultrasonic Monitoring Of Bearing Wear.

LecturePg. 91-98Unpredicted bearing failures continue to plague industry with forced outages. As a result of these outages, many industries have attempted prevention by unnecessary inspections and premature bearing replacement. This work can be associated with significant incurred costs. Bearing failures often occur after a lengthy process of wear, related to factors such as abrasion, corrosion, and erosion. Over the years, several techniques for indirectly measuring bearing condition have been developed and used. These techniques, however, provide imprecise measurements of bearing damage and wear rates. Until recently, the only direct measure of bearing condition was visual inspection and dimensional checks, both requiring shutdown and disassembly. A bearing wear monitoring system has been developed to eliminate the interpretation of indirect symptoms and the need for bearing disassembly. The level of accuracy provides a diagnostic ability far more sensitive to wear than indirect methods such as vibration monitoring. In addition, the system provides data on the location and the extent of the problem. Finally, the ultrasonic technique reduces inspection costs, and eliminates the risk of improper reassembly that may follow inspections