1,508 research outputs found
Time-resolved reflectivity technique: improvement and applications
A new method for determination of the reflectivity of Si in different phase transitions during
pulsed laser irradiation is presented in this paper. This method is applied on TRR spectra of crystalline silicon
(c-Si) in a medium of oxygen and amorphous hydrogenated silicon (a-Si: H). Time resolved reflectivity
(TRR) measurements on silicon has been made during pulsed XeCl excimer laser irradiation (308 nm, 28nm
FWHM) in a medium of oxygen. The samples were irradiated in the energy density range 400−100mJ/cm2.
The reflectivity was measured with a probe He-Ne laser (632.8 nm). Depending on the energy density of the
excimer pulse, heating, melting and resolidification of the surface were monitored by TRR spectra. From
these measurements we were able to determine the melting threshold energy density for c-Si, depending on
the energy densities, time of melting and maximum reflectivity have been measured. TRR spectra of a sample
with 3μm thick a-Si layer for first shot of measurements were calibrated. A series of a-Si: H samples of the
same thickness (0.34 μm) irradiated with a constant energy density 450mJ/cm2 and the three consecutive
TRR spectra of the irradiated samples were calibrated
Simultaneous use of Individual and Joint Regularization Terms in Compressive Sensing: Joint Reconstruction of Multi-Channel Multi-Contrast MRI Acquisitions
Purpose: A time-efficient strategy to acquire high-quality multi-contrast
images is to reconstruct undersampled data with joint regularization terms that
leverage common information across contrasts. However, these terms can cause
leakage of uncommon features among contrasts, compromising diagnostic utility.
The goal of this study is to develop a compressive sensing method for
multi-channel multi-contrast magnetic resonance imaging (MRI) that optimally
utilizes shared information while preventing feature leakage.
Theory: Joint regularization terms group sparsity and colour total variation
are used to exploit common features across images while individual sparsity and
total variation are also used to prevent leakage of distinct features across
contrasts. The multi-channel multi-contrast reconstruction problem is solved
via a fast algorithm based on Alternating Direction Method of Multipliers.
Methods: The proposed method is compared against using only individual and
only joint regularization terms in reconstruction. Comparisons were performed
on single-channel simulated and multi-channel in-vivo datasets in terms of
reconstruction quality and neuroradiologist reader scores.
Results: The proposed method demonstrates rapid convergence and improved
image quality for both simulated and in-vivo datasets. Furthermore, while
reconstructions that solely use joint regularization terms are prone to
leakage-of-features, the proposed method reliably avoids leakage via
simultaneous use of joint and individual terms.
Conclusion: The proposed compressive sensing method performs fast
reconstruction of multi-channel multi-contrast MRI data with improved image
quality. It offers reliability against feature leakage in joint
reconstructions, thereby holding great promise for clinical use.Comment: 13 pages, 13 figures. Submitted for possible publicatio
Determination of limiting nutrient to Sweetpotato ((L.) growth on Samoa Oxisol using a Ipomoea batatas nutrient omission technique
This study was conducted to investigate the influence of various macroand micronutrients on the growth and root yield of sweetpotato (variety IB/PH/03) grown in a Samoan Oxisol under semi-controlled screenhouse conditions. The following nutrient elements were considered: N, P, K, Mg, S,B, Cu, Fe, Mo, Mn, Ni, and Zn. The set-up involved pot nutrient omission trials wherein the twelve nutrient elements were combined to form an ALL treatment with subsequent 12 treatments made by excluding one nutrient
consecutively from the ALL combinations. Treatments were arranged in a randomized complete block design with four replications for all treatments while six for the ALL treatment. Results showed that P was the most limiting
factor to sweetpotato vegetative growth and root yield. Reduced storage root yield in relation to ALL were also observed when N, P, K, S, B, Fe, Mn, Mo and Ni were not supplied, although the difference was insignificant. Thus
unless P deficiency is addressed, the deficiency effects of these nutrients on storage root yield remain insignificant
Solitary Langerhans cell histiocytosis of liver with sclerosing cholangitis in an adult female
Liver is affected as a late complication of high risk cases of Langerhans cell histiocytosis. Sclerosing cholangitis is a rare pattern associated with Langerhans cell histiocytosis of liver, which is even rarer in the adult population and has high mortality. The treatment is difficult and may require liver transplantation. We report a unique case of a 40-year-old female who developed sclerosing cholangitis associated with Langerhans cell histiocytosis without any evidence of involvement of other systems. Our patient required only surgery, and had been followed up for two years without recurrence. We could not find any other case of solitary liver involvement of Langerhans cell histiocytosis in literature published so far
TRITIMED; a multidisciplinary project to improve drought adaptation in durum wheat
none6noneHABASH D.; ARAUS J.L.; LATIRI K.; KADER A.A.; TUBEROSA R.; NACHIT M.HABASH D.; ARAUS J.L.; LATIRI K.; KADER A.A.; TUBEROSA R.; NACHIT M
Time-resolved reflectivity technique: improvement and applications
Abstract. A new method for determination of the reflectivity of Si in different phase transitions during pulsed laser irradiation is presented in this paper. This method is applied on TRR spectra of crystalline silicon (c-Si) in a medium of oxygen and amorphous hydrogenated silicon (a-Si : H). Time resolved reflectivity (TRR) measurements on silicon has been made during pulsed XeCl excimer laser irradiation (308 nm, 28 nm FWHM) in a medium of oxygen. The samples were irradiated in the energy density range 400-1100 mJ/cm 2 . The reflectivity was measured with a probe He-Ne laser (632.8 nm). Depending on the energy density of the excimer pulse, heating, melting and resolidification of the surface were monitored by TRR spectra. From these measurements we were able to determine the melting threshold energy density for c-Si, depending on the energy densities, time of melting and maximum reflectivity have been measured. TRR spectra of a sample with 3 µm thick a-Si layer for first shot of measurements were calibrated. A series of a-Si : H samples of the same thickness (0.34 µm) irradiated with a constant energy density 450 mJ/cm 2 and the three consecutive TRR spectra of the irradiated samples were calibrated
Automated server-side model for recognition of security vulnerabilities in scripting languages
With the increase of global accessibility of web applications, maintaining a reasonable security level for both user data and server resources has become an extremely challenging issue. Therefore, static code analysis systems can help web developers to reduce time and cost. In this paper, a new static analysis model is proposed. This model is designed to discover the security problems in scripting languages. The proposed model is implemented in a prototype SCAT, which is a static code analysis Tool. SCAT applies the phases of the proposed model to catch security vulnerabilities in PHP 5.3. Empirical results attest that the proposed prototype is feasible and is able to contribute to the security of real-world web applications. SCAT managed to detect 94% of security vulnerabilities found in the testing benchmarks; this clearly indicates that the proposed model is able to provide an effective solution to complicated web systems by offering benefits of securing private data for users and maintaining web application stability for web applications providers
Soil nitrogen storage and availability to crops are increased by conservation agriculture practices in rice - based cropping systems in the Eastern Gangetic Plains
On-farm adoption of minimum soil disturbance and increased residue retention will alter nitrogen (N) dynamics in soils and N fertiliser management in the intensive rice–based triple cropping systems of the Eastern Gangetic Plains. However, the consequences of changes in N forms, N mineralisation and its availability for crops have not been determined. Field experiments were conducted at two locations (Alipur and Digram) of north–west Bangladesh (NWB) to examine N cycling under three planting practices (conventional tillage (CT), strip planting (SP) and bed planting (BP)) with increased (HR) or low residue retention (LR– the current practice) on Calcareous Brown Flood Plain and Grey Terrace soils. Total N and available N were measured on soil samples as was N uptake by crops at different growth stages in the 13–14th (Alipur) and 12–13th (Digram) crops since treatments commenced. At each location (0–10 cm soil depth), SP, including non–puddled transplanting of rice seedlings (NP), together with HR increased total N by 9 and 32 % relative to BPHR, and CTHR and by 62 % relative to the current farm practice (CTLR). In general, the cumulative available N in soils during mustard and rice cropping under CT with HR was higher than other crop establishment and residue retention practices while under wheat and jute, total availability of N did not vary among crop establishment types with increased residue retention. Nitrogen availability in the initial phase of crop growth (0–60 DAS) was generally higher with CT than SP and BP. By contrast, for all crops, the estimated potentially mineralisable N was higher and its decay rate was lower under SPHR than other crop establishment and residue retention practices. Conservation Agriculture practices (SP, and NP of rice, together with HR) have altered the N cycling by reducing the level of mineral N available to plants in the early growing season when crop demand is low, but by increasing soil total N (0−10 cm) and plant N uptake which enhanced the synchrony between crop demand and available N supply
Determination of optimum level of NPK for cultivation of sweetpotato in Samoa
Establishment of a sound fertiliser dose is necessary for achieving higher yield, soil fertility protection and environmental sustainability. Currently, there is no data pertaining to the optimum fertiliser requirement for sweetpotato under Samoan situation. To achieve this, an experiment was conducted to determine the optimum NPK levels for three sweetpotato cultivars under screen-house and field conditions in Samoa. The experiment includes four levels of NPK in kg/ha equivalent (control, 30:30:30, 60:60:60, and 90:90:90) and three improved sweetpotato cultivars (IB/PH/03, IB/PR/12, and IB/PR/13). Results revealed that each cultivar exhibited remarkably varied responses to NPK levels. Yield of IB/PH/03 increased consistently with increasing NPK levels indicating that, the applied NPK levels was insufficient to determine optimum NPK level. Cultivar IB/PR/13 followed a typical crop response curve, however, IB/PR/12 failed to produce significantly higher yield with increased level of NPK. Based on a quadratic model, the putative optimum NPK level for IB/PR/13 and IB/PR/12 was determined - 49-49-49 and 42-42-42 kg/ha respectively, however, the most profitable NPK levels were 30-30-30 and 18-18-18 kg/ha, respectively. Although the profitable NPK level was the highest level for IB/PH/03, it has not been possible to determine the optimum NPK level correctly. Thus, further studies are suggested to test higher NPK dose for IB/PH/03 and other varieties of sweetpotato under wider soil conditions in order to verify the result. This study would be a good basis for future study in a wide range of sols in Samoa and sweetpotato cultivars to achieve conclusive findings
Low maternal education and socioeconomic status were associated with household food insecurity in children under five with diarrhoea in Bangladesh.
Household food insecurity (HFI) is insufficient access to nutritionally safe and adequate foods to meet the dietary needs for an active and healthy life. We examined the prevalence and determinants of HFI in Bangladeshi children under five with diarrhoea
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