798 research outputs found
Influence of base and photoacid generator on deprotection blur in extreme ultraviolet photoresists and some thoughts on shot noise
A contact-hole deprotection blur metric has been used to monitor the deprotection blur of an experimental open platform resist (EH27) as the wt % of base and photoacid generator (PAG) were varied. A six times increase in base wt % is shown to reduce the size of successfully patterned 1:1 line-space features from 52 to 39 nm without changing deprotection blur. Corresponding isolated line edge roughness is reduced from 6.9 to 4.1 nm. A two times increase in PAG wt % is shown to improve 1:1 line-space patterning from 47 to 40 nm without changing deprotection blur or isolated line edge roughness. A discussion of improved patterning performance as related to shot noise and deprotection blur concludes with a speculation that the spatial distribution of PAG molecules has been playing some role, perhaps a dominant one, in determining the uniformity of photogenerated acids in the resists that have been studied. © 2008 American Vacuum Society
Cytomegalovirus infection of the upper gastrointestinal tract following liver transplantation—incidence, location, and severity in cyclosporine- and FK506-treated patients
One hundred and forty randomly selected liver transplant recipients were studied before and after primary orthotopic liver transplantation for the presence or absence of CMV enteritis. Following OLTx, 65 patients were treated with cyclosporine A and 75 were treated with FK506. The two groups were similar with regard to the incidence, location, and outcome of their upper gastrointestinal CMV infection. Prior to OLTx, only one patient had evidence of enteric CMV infection. The incidence of CMV enteritis post-OLTx was 27.7% in the CsA-treated group and 20% in the FK-treated group. During the first posttransplant month, no patient in the FK-treated group developed CMV enteritis, compared with 11.5% of the patients who were treated with CsA (P<0.05). Gastric CMV was found in over 80% of those positive for any organ in either group. In addition to CMV infection of the upper gastrointestinal tract, clinically evident CMV disease involved more nonenteric organs in the CsA-treated group than in the FK-treated group. In the CsA-treated group, CMV-negative patients had a statistically higher 1-year survival rate (100%) than CMV-positive patients (77.8%) (P<0.05). In the FK-treated group, no difference in survival was observed between CMV-positive or CMV-negative cases at 1 year. Of the patients on CsA, 20% received OKT3 for persistent rejection, as compared with 13% in the FK-treated group. The patients receiving both CsA and OKT3 had a higher rate of upper gastrointestinal CMV infection than did FK-treated patients who also received OKT3 therapy (38.5% versus 20%, respectively). Based upon these data, it can be concluded that (1) patients receiving FK have a lower incidence of enteric CMV infection; (2) following OLTx, upper gastrointestinal CMV infection presents later in FK-treated patients; (3) the stomach is the most frequently involved organ in the UGIT; (4) FK-treated liver recipients have less severe enteric CMV infection than do CsA-treated patients; (5) enteric CMV is not a major cause of mortality in liver trans lant recipients; and (6) in patients receiving FK, those who require OKT3 therapy do not appear to be at a greater risk for the development of CMV enteritis than those who do not. © 1992 by Williams & Wilkins
Double-pulse Nd:YAG-CO2 LIBS Excitation for Bulk and Trace Analytes
Laser-induced breakdown spectroscopy [LIBS] is a commonly used technique for multi-element analyses for various applications such as space exploration, nuclear forensics, environmental analysis, process monitoring. The advantages of the LIBS technique include robustness, ease of use, field portability, and real-time, non-invasive multi-element analyses. However, in comparison to other lab based analytical techniques, it suffers from low precision and low sensitivity. In order to overcome these drawbacks, various approaches have been used, including double-pulse LIBS [DPLIBS]. Typically, various wavelength combinations of two Nd: yttrium aluminum garnet [YAG] lasers have been used for DPLIBS. However, the use of long wavelength (CO2) laser in combination with Nd:YAG laser has not been sufficiently studied. In this study, signal enhancement mechanisms in Nd:YAG:CO2 DPLIBS are investigated. Nd:YAG laser pulse at 1064 nm was used as pre-ablation laser while CO2 laser at 10.6 μm was used as reheating laser pulse. The results exhibit significant improvement in sensitivity of both bulk and trace analytes in the sample using DPLIBS as compared to conventional single-pulse LIBS [SPLIBS]. The bulk and trace analytes used for comparing figures of merit in the brass sample were Cu and Fe emission lines, respectively. Pre-pulse energies ranging from 20 to 120 mJ from a 1064 nm Nd: YAG laser reheated by a 10.6 μm TEA CO2 laser at constant energy of 400 mJ aligned in near collinear geometry. The observed signal intensity and signal-to-background ratio of bulk analyte as well as trace analyte increased significantly. In order to understand signal enhancement mechanisms, various experimental parameters apart from pre-pulse energy were also studied, including inter-pulse delay and ICCD gate delay. Time resolved studies showed that persistence of neutral lines increases by ~10 times for DPLIBS as compared to SPLIBS. Plasma was characterized by estimation of excitation temperature and electron density using the Boltzmann method and Stark broadening method, respectively. Plasma temperature was found to be higher for DPLIBS, which shows that reheating mechanism is dominant mechanism for signal enhancement and increased persistence in YAG:CO2 DPLIBS. The mechanisms involved in signal enhancement and persistence of neutral and ionic species from bulk and trace analyte are presented and their implications to improving figures of merit are discussed
Analysis of Chemical and Microbial Change During Storage of Overripe Tempeh Powder as Seasoning Material
Tempeh and other soy-derived products are historically and currently some of the most important foods in the Asian region where diets remain predominantly plant-based. Overripe tempeh (tempe semangit) is a term used for over-fermented tempeh with pungent odor and darkening appearance commonly used in Javanese cuisine. Unique taste and odor of overripe tempeh lead to the exploration of its potencies as condiment, which may add the nutritional, safety and economic values of tempeh. In this research, overripe tempeh is made into powder for better appearance and availability. Oven drying at 60oC and freeze drying were applied to the overripe tempeh until it reached moisture content below 5%, followed by subsequent crushing into powder using electric grinding machine. As seasoning material, the tempeh powder and overripe tempeh powder were then analyzed for their stability. Observations in chemical and microbial changes during storage were also applied to selected product during storage. Parameters observed during the research are: moisture content, protein content, acid content, total microbial count and total coliform. Oven dried overripe tempeh (S60) has higher moisture content but lower in acid content, total microbial count and total coliform compared to freeze dried overripe tempeh (SFD)
The Molecular Adsorbents Recycling System as a Liver Support System Based on Albumin Dialysis: A Summary of Preclinical Investigations, Prospective, Randomized, Controlled Clinical Trial, and Clinical Experience from 19 Centers
Artificial liver support aims to prolong survival time of patients with liver failure by detoxification. Albumin as a molecular adsorbent in dialysis solution is capable of attracting even tightly albumin-bound toxins from blood into the dialysate if a specific dialysis membrane is used and if the albumin's binding sites are on-line-purified by a sorbent/dialysis-based recycling system (i.e., molecular adsorbents recycling system, or MARS). The MARS technology has been shown to remove water-soluble and albumin-bound toxins and to provide renal support in case of renal failure. Fourteen centers have reported that MARS treatment improved mental status of patients with liver failure and hepatic encephalopathy. In treating liver failure and cholestasis, MARS was associated with hemodynamic stabilization, improvement of hepatic and kidney function, and disappearance of pruritus. In hepatic failure and hepatorenal syndrome, a prospective, randomized, controlled trial of MARS treatment was able to prolong survival time significantly. MARS has been used in 26 patients with acute liver failure or primary graft dysfunction. Nineteen centers reporting on 103 patients have shown that MARS treatment is safe, easy to handle, feasible, and effective.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73869/1/j.1525-1594.2002.06822.x.pd
Analysing greenhouse ventilation using Computational Fluid Dynamics (CFD)
This is the author accepted manuscript. The final version is available from UKACM via the link in this recordGreenhouses (GH) are used to shield the crops from excessive cold or heat. They are used for growing certain
types of cultivations during the year round. The aim of this study is to design a greenhouse using solar-powered
technology to produce a Zero-Liquid-Discharge (ZLD) by using Solar Stills and adding condensers to dehumidify
the excess vapoured water. This allows to have small-scale plants to reduce the cost of water treatment while
increasing its sustainability. Computational fluid dynamics was used to find the best locations for the dehumidifiers
in the GH and design the necessary ventilation. This can help to plan ahead and evaluate the optimal amount of
produced water for different sizes of greenhouse before they are constructed physically.British Council - EgyptScience & Technology Development Fund (STDF), Egyp
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US ITER limiter module design
The recent U.S. effort on the ITER (International Thermonuclear Experimental Reactor) shield has been focused on the limiter module design. This is a multi-disciplinary effort that covers design layout, fabrication, thermal hydraulics, materials evaluation, thermo- mechanical response, and predicted response during off-normal events. The results of design analyses are presented. Conclusions and recommendations are also presented concerning, the capability of the limiter modules to meet performance goals and to be fabricated within design specifications using existing technology
On twisted ordered monoid rings over quasi-Baer rings
In this paper we show that if M is an Ordered monoid then the twisted monoid ring R^T M is (left principally) quasi-Baer if and only if R is (left principally) quasi-Baer. Also if R is (left principally) quasi-Baer and G is an ordered group acting on R we give a necessary and sufficient condition for the crossed product R∗G to be (left principally) quasi-Baer
Role of stigmasterol treatment in alleviating the adverse effects of salt stress in flax plant
Abstract The results revealed that application of stigmasterol to salt -stressed flax plants causing significantly increased in growth parameters, membrane stability index, photosynthetic pigment and carbohydrate contents compared with salt-stressed plants untreated with stigmasterol. The level of antioxidant system components (catalase, ascorbic acid peroxidase) and reduced glutathione with increased in response to stigmasterol treatment. Enhanced antioxidant activities helped to decrease oxidative damage from salt and develop tolerance against salt stress in stigmasterol -treated flax plants. Stigmasterol treatment increase in the degree of salt tolerance by improvement of the membrane stability index, photosynthetic activity and carbohydrate contents. The data provided evidence that seeds soaking in stigmasterol reduced the adverse effects of salt stress on flax plants by stimulation of the antioxidant system as a stress protection mechanism
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