Development of design allowable data for Celion 6000/LARC-160, graphite/polyimide composite laminates

A design allowables test program was conducted on Celion 6000/LARC-160 graphite polyimide composite to establish material performance over a 116 K (-250 F) to 589 K (600 F) temperature range. Tension, compression, in-plane shear and short beam shear properties were determined for uniaxial, quasi-isotropic and + or - 45 deg laminates. Effects of thermal aging and moisture saturation on mechanical properties were also evaluated. Celion 6000/LARC-160 graphite/polyimide can be considered an acceptable material system for structural applications to 589 K (600 F)

Shipping & Handling

M.A. Thesis. University of Hawaiʻi at Mānoa 2018

AC Loss and Contact Resistance In Copper-Stabilized Nb3Al Rutherford Cables with and without a Stainless Steel Core

Calorimetric measurements of AC loss and hence interstrand contact resistance (ICR), were measured on three samples of Rutherford cable wound with Cu-stabilized jelly-roll type unplated Nb3Al strand. One of the cable types was furnished with a thin core of AISI 316L stainless steel and the other two were both uncored but insulated in different ways. The cables were subjected to a room-temperature-applied uniaxial pressure of 12 MPa that was maintained during the reaction heat treatment (RHT), then vacuum impregnated with CTD 101 epoxy, and repressurized to 100 MPa during AC-loss measurement. The measurements were performed at 4.2 K in a sinusoidal field of amplitude 400 mT at frequencies of 1 to 90 mHz (no DC-bias field) that was applied both perpendicular and parallel to the face of the cable (the face-on, FO, and edge-on, EO, directions, respectively). For the cored cable the FO-measured effective ICR (FO-ICR), was 5.27 . Those for the uncored cables were less than 0.08 . As shown previously for NbTi- and Nb3Sn-based Rutherford cables, the FO-ICR can be significantly increased by the insertion of a core, although in this case it is still below the range recommended for accelerator-magnet use. Post-measurement dissection of one of the cables showed that the impregnating resin had permeated between the strands and coated the core with a thin, insulating layer excepting for some sintered points of contact. In the uncored cables the strands were coated with resin except for the points of interstrand contact. It is suggested that in the latter case this tendency for partial coating leads to a processing-sensitive FO-ICR.Comment: Four pages, with two figure

Assistance to the tourist industry

This study has been carried out as part of the government's continuing review of the economy, in particular the levels of assistance provided to various sectors, and examines the levels of assistance given to the tourism sector in New Zealand. The measurement of the effective rates of assistance (as distinct from effective rate of protection) is a relatively new concept but has recently become accepted as a comparative analysis tool. It allows different forms of assistance to be aggregated and for a comparison of the assistance to different sectors of the economy

Is it worth subsoil testing for Nitrogen?

In WA, soil testing for mineral N (ammonium plus nitrate) has traditionally been taken from the top 0-0.1 m. Farmers and advisors are now interested in deeper soil testing, in order to know how much mineral N occurs at depth and what this may mean in terms of fertiliser N application decisions. Accounting for topsoil and subsoil test level in N fertiliser use varies markedly among growers and advisors depending on; their own historic applications; use of nitrogen decision support tools (N-DSS’s) such as Yield Prophet simulations or SYN. Other growers use approximate total soil profile N and then add N fertiliser required to reach target yield (i.e. 45 kg N/ha for 1 t/ha of grain). The main question this paper is addressing is “Do I need to soil test to depth for better N decisions?” To answer this we needed to understand: 1. Where in the profile the subsoil N occurs and if it is related to topsoil N, 2. How effective is the subsoil in supplying N for the crop – which depends on root access to subsoil N as affected by subsoil constraints and N leaching, 3. What does this mean for N recommendation systems based on soil testing? and 4. Given the seasonal interaction with yield response, will the subsoil N test results reduce the errors in recommendations enough to justify this extra complexity, cost and effort

Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain production: A review

Abstract Negative potassium (K) balances on farmlands globally are widespread because fertiliser K input is often less than losses (leaching) and removal of K in hay, straw and grain, which leads to a rundown of plant-available K. When soil K reserves are not large and the plant-available K pools are not well buffered, the risk of K rundown in soils is high. In the south-west of Western Australia, soil K rundown, particularly by continuous cropping or in systems where a large portion of crop biomass is removed, is increasing the prevalence of crop K deficiency even on soils where K was not previously a limiting factor for crop yields. While fertiliser K is required for adequate supply of plant-available K, maximising K use efficiency is also important for cropping profitability and sustainability in dryland agriculture. Plant K uptake and use efficiency can be affected by soil types, crop species and sequences, seasonal conditions, and K management. In water-limited environments, crop K nutrition, especially root access to subsoil K, plays a crucial role in promoting root growth, regulating plant water relations and alleviating biotic and abiotic stresses. Optimised use of both soil and fertiliser K is increasingly necessary to sustain crop yields under stressed conditions in the context of K rundown in soils