A study on nuclear analysis of the divertor region of the CFETR

This paper presents the nuclear analysis performance of the Chinese Fusion Engineering Test Reactor(CFETR)divertor region using the MCNP-5 Monte Carlo N-particles code in a 3D geometry model.We assessed the nuclear responses of the divertor region component systems and evaluated their shielding capability,which can support the development strategy of the physical and engineering design of the CFETR.Model specification based on the latest CAD model of the CFETR divertor has been integrated into the CFETR MCNP reference model with a major/minor radius R=7.2 m/a=2.2 m in the 22.5° model,and a fusion-power range of around 1-1.5 GW.The nuclear heating and radiation damage of the divertor system are enhanced compared to that of the ITER and the earlier CFETR design.The initial nuclear responses of the toroidal field coil and vacuum vessel systems showed that the shielding of the current divertor design is not sufficient and optimization work has been carried out.We also carried out calculations and analysis using a hypothetical operating scenario of over 14 years.An excellent improvement in the nuclear performance has been obtained by the improved additional shielding block in the divertor region when referring to the ITER design limit,which can support the design of the future update of the divertor region systems of the CFETR.     

Melanoma Biomarkers and Their Potential Application for In Vivo Diagnostic Imaging Modalities

Melanoma is the deadliest form of skin cancer and remains a diagnostic challenge in the dermatology clinic. Several non-invasive imaging techniques have been developed to identify melanoma. The signal source in each of these modalities is based on the alteration of physical characteristics of the tissue from healthy/benign to melanoma. However, as these characteristics are not always sufficiently specific, the current imaging techniques are not adequate for use in the clinical setting. A more robust way of melanoma diagnosis is to “stain” or selectively target the suspect tissue with a melanoma biomarker attached to a contrast enhancer of one imaging modality. Here, we categorize and review known melanoma diagnostic biomarkers with the goal of guiding skin imaging experts to design an appropriate diagnostic tool for differentiating between melanoma and benign lesions with a high specificity and sensitivity.     

A comparative study of 1/f noise and temperature coefficient of resistance in multiwall and single-wall carbon nanotube bolometers

The 1/f noise and temperature coefficient of resistance (TCR) are investigated in multiwall carbon nanotube (MWCNT) film bolometers since both affect the bolometer detectivity directly. A comparison is made between the MWCNT film bolometers and their single-wall carbon nanotube (SWCNT) counterparts. The intrinsic noise level in the former has been found at least two orders of magnitude lower than that in the latter, which outweighs the moderately lower TCR absolute values in the former and results in higher bolometer detectivity in MWCNT bolometers. Interestingly, reduced noise and enhanced TCR can be obtained by improving the inter-tube coupling using thermal annealing in both SWCNT and MWCNT films, suggesting much higher detectivity may be achieved via engineering the inter-tube coupling.     

Nitrate content in lettuce (Lactuca sativa L) heads in relation to plant spacing,nitrogen form and irrigation level

A field study was conducted at two locations (Jordan valley and Al‐Jubeiha) with different rainfall levels, altitudes and temperature ranges. The study was established to evaluate the optimum planting density, nitrogen (N) form and irrigation level to attain the best quality of lettuce crop in terms of minimum nitrate (NO₃) content and to minimise the impact on the environment. Seeds of ‘Amar’ lettuce were sown 1 month before transplanting. Three forms of N fertiliser (Ca(NO₃)₂, (NH₄)₂SO₄ and CO(NH₂)₂) were applied at three times at a total rate of 100 kg N ha^?1. Three in‐row spacings (15, 20 and 25 cm) were assigned. Two irrigation levels were applied: level 1 had twice the amount of irrigation water as level 2, which was achieved by doubling the number of irrigation lines. The results indicated that N form significantly increased both N and NO₃ contents. Ca(NO₃)₂ was the most effective in increasing the N and NO₃ contents in lettuce leaf tissues, followed by CO(NH₂)₂ and then (NH₄)₂SO₄. The outer leaves (green colour) had about five times the NO₃ content of the inner leaves (pale yellow colour). However, the effect of N form on production, total N absorption and N recovery was significant in the following order: (NH₄)₂SO₄ > Ca(NO₃)₂ > CO(NH₂)₂. Increasing the plant spacing resulted in a significant increase in N and NO₃ contents in the lettuce leaves. Copyright © 2004 Society of Chemical Industry