The Tau Parallel Performance System Shende, Sameer S.; Malony, Allen D.
The international journal of high performance computing applications,
07/2006, Letnik:
20, Številka:
2
Journal Article
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Odprti dostop
The ability of performance technology to keep pace with the growing complexity of
parallel and distributed systems depends on robust performance frameworks that can
at once provide system-specific ...performance capabilities and support high-level
performance problem solving. Flexibility and portability in empirical methods and
processes are influenced primarily by the strategies available for instrmentation
and measurement, and how effectively they are integrated and composed. This paper
presents the TAU (Tuning and Analysis Utilities) parallel performance sytem and
describe how it addresses diverse requirements for performance observation and analysis.
The asymmetric reduction of unsaturated carbonyl functionalities is one of the most important chemical transformations to generate optically active stereocenters. Optically active secondary alcohols ...are a class of compounds which displays significant importance as various intermediates, chiral building blocks and biologically active compounds. Various methods have been utilized for the synthesis of these secondary alcohols to achieve high activity and enantioselectivity for reduction reactions of prochiral ketones. Organocatalysis plays a pivotal role in the area of asymmetric synthesis. Recently, several types of organocatalysts have been investigated for asymmetric reduction of prochiral ketones to obtain chiral alcohols with excellent enantioselectivity. This review is focused on selected studies on the development of organocatalysts which are classified into six major categories: i) oxazaborolidine, ii) hydroxyamide, iii) BINOL, iv) ionic liquid, v) phosphoric acid and vi) thiourea-amine based catalysts for asymmetric reduction of prochiral ketones. Mechanistic studies performed in this area are also briefly summarised herein. This review specifically focuses on the most recent applications of organocatalysts used for reduction of ketones for the past seven years.
This review depicts the recent practices followed in organocatalyzed asymmetric reduction of prochiral ketones, highlighting the main organocatalysts used for the past seven years.
In this work, the synthesis of a catalyst with Ru metal supported on a montmorillonite (MMT) support was performed and the prepared catalyst was characterized
via
different characterization ...techniques such as: SEM, XRD, XPS, EDX, TEM, and TGA. The catalytic effect of the prepared Ru-MMT with various wt% of Ru metal were determined for the dehydration reaction of fructose to 5-hydroxymethylfurfural (HMF), and for the efficient oxidation of HMF into 2,5-diformylfuran (DFF). HMF conversion occurred completely in 4 h of reaction time to obtain DFF with a 96% yield at 120 °C and an oxygen pressure of 3 bar in dimethyl sulfoxide (DMSO) solvent with 2 wt% of the Ru-MMT catalyst. A one-pot, two-step reaction produced a yield of 89% DFF with 100% conversion of fructose, however an 81% yield of DFF was achieved from a one-pot, one-step reaction using the 2 wt% Ru-MMT catalyst. The catalyst can be isolated easily after the completion of the reaction and successfully reused up to five times with no substantial loss of catalyst activity. The practical applicability of the developed catalyst was successfully demonstrated for the direct transformation of various carbohydrates (glucose, inulin, sucrose, starch, raffinose, and maltose) to DFF in moderate to good yields (35-64% yield). Overall, the 2 wt% Ru-MMT catalyst demonstrated excellent catalytic activity for the one-pot transformation of fructose to DFF showing an excellent yield of DFF in a short reaction time, and afforded wide substrate applicability, good recyclability and catalyst stability.
Ruthenium metal supported on a montmorillonite (2 wt% Ru-MMT) catalyst have been synthesized and characterized. Catalyst found to be effective for the one-pot transformation of fructose to DFF showing an excellent yield with good recyclability.
The modern agricultural system is facing the unprecedented task of contriving the extensive demand for agrarian production owing to population explosion and global climate change. The employment of ...Nanotechnology in agriculture has gained immense interest in recent times for the development of sustainable agricultural technologies and environmental remediation strategies. Nanotechnology pertains to the employment of nanoparticles and furnishes the potential to fabricate novel materials and products possessing improved quality. The nanomaterials may be used as; nanosensors, nanocides, nanofertilizers, nanobarcodes, and nano-remediators, which play a significant role in modern agricultural practices. However, the physical and chemical processes of nanoparticle production is neither economical nor environmentally sustainable. Therefore, the need for green or biogenic nanoparticles obtained from plants, bacteria, fungi or their metabolites has emerged as novel, sustainable, economical, biocompatible, and eco-friendly technology. In this perspective, the production and sources of biogenic nanoparticles and their implication in agro-ecosystems for crop productivity, soil health management, biocontrol, and environmental remediation have been focused on in this review. The potential development and implementation challenges are also explored.
The present paper explores the correlation between fracto-mechanoluminescence and fracture of solids and thereby provides a clear understanding of the physics of fracto-mechanoluminescence. When a ...fluorescent or non-photoluminescent crystal is fractured impulsively by dropping a load on it, then initially the mechanoluminescence (ML) intensity increases linearly with time, attains a maximum value Im at a particular time tm and later on it decreases exponentially with time. However, when a phosphorescent crystal is fractured impulsively by dropping a load on it, then initially the ML intensity increases linearly with time, attains a maximum value Im at a particular time tm and later on it decreases initially at a fast rate and then at a slow rate. For low impact velocity the value of tm is constant, however, for higher impact velocity tm decreases logarithmally with the increasing impact velocity. Whereas the peak ML intensity Im increases linearly with the impact velocity, the total ML intensity IT, initially increases linearly with the impact velocity and then it tends to attain a saturation value for higher values of the impact velocity. The value of tm increases logarithmally with the thickness of crystals, Im increases linearly with the area of cross-section of crystals and IT increases linearly with the volume of crystals. Generally, the ML of non-irradiated crystals decreases with increasing temperature of crystals. Depending on the prevailing conditions the ML spectra consist of either gas discharge spectra or solid state luminescence spectra or combination of the both. On the basis of the rate of generation of cracks and the rate of creation of new surface area of crystals, expressions are derived for the ML intensity and they are found to explain satisfactorily the temporal, spectral, thermal, crystal-size, impact velocity, surface area, and other characteristics of ML. The present investigation may be useful in designing of damage sensors, fracture sensors, ML-based safety management monitoring system, fuse-system for army warheads, milling machine, etc. The present study may be helpful in understanding the processes involved in earthquakes, earthquake lights and mine-failure as they basically involve fracture of solids.
► The correlation between fracto-mechanoluminescence and fracture of solids is explored. ► A clear understanding of the physics of fracto-mechanoluminescence is reported. ► The study may be useful in designing the ML-based devices. ► The study may be helpful in understanding earthquakes, and earthquake lights.
This study investigated the acute and subacute oral toxicity of SE- Oil, SE-Alcohol and SE-Chloro extracts of Senecio edgeworthii (SE) in a rodent for evaluating its safety profile. Senecio ...edgeworthii (SE) plant for the acute oral toxicity (300 to 5000mg/kg) and subacute oral toxicity SE- Oil (SE-Oil 50, 200, 500mg/kg) and SE-Chloro (SEC 100, 500, 1000mg/kg) and SE-Alcohol (SEA 100, 500, 1000mg/kg) studies were administered orally according to the guidelines 423 and 407 of OECD, respectively. In the acute oral toxicity study, doses are administered by 300mg/kg, 1000mg/kg, 2000mg/kg and 5000mg/kg (OECD guideline no. 423). SEA and SEC do not show toxicity up to 5000mg/kg; SE- Oil shows toxicity at a dose of 2500mg/kg. In the subacute toxicity study, the daily oral treatment with extracts of SEA and SEC 100, 500, 1000mg/kg, SE-Oil 50, 250, 500mg/kg of extracts for 28 days did not produce any death or hazard. Likewise, SEA and SEC 100, 500, 1000mg/kg, SE-Oil 50, 250mg/kg of Senecio edgeworthii hook no significant changes were recorded in food intake, body weight gain, the biochemical and haematological parameter of control and treated rats. SE-Oil 500mg/kg of significant changes were recorded in food intake and body weight gains are decreased compared to the control group and SE-Oil 500mg/kg there was a significant (P < 0.05) decrease in RBC counts in the treated animals compared to that of the control group counts in the treated animals and induction (ALT, AST, and alkaline phosphatase and Total protein). SE- Oil 500mg/kg of extract treaded group saw mild liver pathological findings characterized by abnormal hepatic configuration was observed with treated animals. The present result from the acute and subacute toxicity study Senecio edgeworthii hook alcohol and chloroform extract is considered relatively safe on acute and subacute oral exposure. Senecio edgeworthii hook flower hexane extract shows acute toxicity at dose 2500mg/kg and in subacute toxicity study, higher dose 500mg/kg.
Global crop protection and food security have become critical issues to achieve the ‘Zero Hunger’ goal in recent years, as significant crop damage is primarily caused by biotic factors. Applying ...nanoparticles in agriculture could enhance crop yield. Nano-silver, or AgNPs, have colossal importance in many fields like biomedical, agriculture, and the environment due to their antimicrobial potential. In this context, nano-silver was fabricated by
Citrus medica
L. (Cm) fruit juice, detected visually and by UV–Vis spectrophotometric analysis. Further, AgNPs were characterized by advanced techniques. UV–Vis spectroscopic analysis revealed absorbance spectra at around 487 nm. The zeta potential measurement value was noted as -23.7 mV. Spectral analysis by FT-IR proved the capping of the acidic groups. In contrast, the XRD analysis showed the Miller indices like the face-centered cubic (
fcc
) crystalline structure. NTA revealed a mean size of 35 nm for nano-silver with a 2.4 × 10
8
particles mL
−1
concentration. TEM analysis demonstrated spherical Cm-AgNPs with 20–30 nm sizes. The focus of this research was to evaluate the antifungal activity of biogenic AgNPs against post-harvest pathogenic fungi, including
Aspergillus niger
,
A. flavus
, and
Alternaria alternata.
The Cm-AgNPs showed significant antifungal activity in the order of
A. niger
>
A. flavus
>
A. alternata.
The biogenic Cm-AgNPs can be used for the inhibition of toxigenic fungi.
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•Synthesis of ruthenium ion supported on IL immobilized into graphene oxide (Ru@GOIL).•Characterized Ru@GOIL catalyst by FT-IR, XRD, XPS, TGA, FEG-SEM, TEM and EXAFS ...analysis.•Ru@GOIL: Effective catalyst for reductive amination of LA with different amines.•Synthesized various N-substituted pyrrolidones (~95% yields) and achieved 6 recycles.•Direct transformation of biomass derived LA to N-substituted pyrrolidones by Ru@GOIL.
Reductive amination of biomass derived Levulinic acid (LA) for the synthesis of N-substituted pyrrolidones is one of the highly attractive routes for biomass valorization. The supported homogeneous metal precursor into the solid surface is an important context in the field of catalysis because these types of catalysts provide the heterogeneous nature and meet the needs of recyclability. Herein, we have reported a synthesis of catalyst with ruthenium ion supported on ionic liquid immobilized into graphene oxide (Ru@GOIL) and its application for reductive amination reaction. Synthesized catalyst is characterized using different analytical techniques such as FT-IR, XRD, XPS, TGA, FEG-SEM, TEM and EXAFS analysis. The prepared Ru@GOIL found to be highly effective for reductive amination of LA and under these optimized conditions various N-substituted pyrrolidones derivatives were synthesized in excellent yield (78–93%). Ru@GOIL catalyst demonstrated great catalytic performance for reductive amination reaction of LA giving good turnover frequency (TOF = 62 h−1) value in comparison with other catalysts. The Ru@GOIL catalyst was recycled for six reaction runs with slight drop-in activity after 4th cycle. Practical applicability of the developed catalyst was successfully demonstrated by direct transformation of biomass waste (rice husk and wheat straw) derived LA to N-substituted pyrrolidones.
Agriculture is a backbone of global economy and most of the population relies on this sector for their livelihood. Chitosan as a biodegradable material thus can be explored for in various fields in ...its nano form to replace non-biodegradable and toxic compounds. The chitosan has appealing properties like biocompatibility, non-toxicity, biodegradability, and low allergenic, making it useful in several applications including in agriculture sector. Because of their unique properties, chitosan nanoparticles (ChNPs) are extensively applied as a bioagent in various biological and biomedical processes, including wastewater treatment, plant growth promoter, fungicidal agent, wound healing, and scaffold for tissue engineering.
Furthermore, the biocompatibility of chitosan nanoparticles (ChNPs) is reported to have other biological properties such as anti-cancerous, antifungal, antioxidant activities, even induces an immune response in the plant, and helps manage biotic and abiotic stresses. Chitosan can also find its application in wastewater treatment, hydrating agents in cosmetics, the food industry, paper, and the textile industry as adhesive, drug-delivering agent in medical as well as for bioimaging. Since chitosan has low toxicity, the nano-formulation of chitosan can be used for the controlled release of fertilizers, pesticides, and plant growth promoters in agriculture fields. The ChNPs applications in precision farming being a novel approach in recent developments. Here we have comprehensively reviewed the major points in this review are; the synthesis of ChNPs by biological resources, their modification and formulation for increasing its applicability, their modified types, and the different agricultural applications of ChNPs.
Biological synthesis; Chitosan nanoparticles (ChNPs); Fertilizer; Fungicidal agent; Plant growth promoter.
The current work sets out to design and develop a carbamazepine (CBZ) extended-release tablet in the treatment of epilepsy using wet granulation technology. The tablets were prepared using HPMC K ...100M and ethyl cellulose as hydrophilic and hydrophobic polymers, respectively. The effect of the concentration of the polymer was studied. The studies indicated that the drug release can be modulated by varying the concentration of the polymer. Tapped density, bulk density, angle of repose, Hausner's ratio, and Carr's index were all calculated for powder blends. The prepared trial batches of tablets were first characterized for hardness, friability, weight variation, and drug content to select an optimized batch. An in-vitro dissolution study of the optimized batch (F4) was carried out in distilled water using a USP Type I (basket type) dissolution apparatus at 100rpm. The optimized formulation (F4) showed a drug content of 99.51%. In-vitro drug release of optimized formulation was found to be 88.10% in 24hours. The optimised formulation demonstrated release for up to 24 hours. The optimised formulation's stability was studied for three months at 40±2ºC/75±5% RH, 30±2ºC/65±5% RH, and 25±2ºC/60±5% RH, and the prepared tablets showed no remarkable effect from the stability study. The results suggest that the developed extended-release tablets of CBZ (400 mg) could perform as therapeutically equivalent alternatives to conventional dosage forms, leading to better patient compliance.
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