Minimum Amount (minimum + amount)

Distribution by Scientific Domains


Selected Abstracts


Analysis of historical landslide time series in the Emilia-Romagna region, northern Italy

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 10 2010
Mauro Rossi
Abstract A catalogue of historical landslides, 1951,2002, for three provinces in the Emilia-Romagna region of northern Italy is presented and its statistical properties studied. The catalogue consists of 2255 reported landslides and is based on historical archives and chronicles. We use two measures for the intensity of landsliding over time: (i) the number of reported landslides in a day (DL) and (ii) the number of reported landslides in an event (Sevent), where an event is one or more consecutive days with landsliding. From 1951,2002 in our study area there were 1057 days with 1 , DL ,?45 landslides per day, and 596 events with 1 , Sevent , 129 landslides per event. In the first set of analyses, we find that the probability density of landslide intensities in the time series are power-law distributed over at least two-orders of magnitude, with exponent of about ,2·0. Although our data is a proxy for landsliding built from newspaper reports, it is the first tentative evidence that the frequency-size of triggered landslide events over time (not just the landslides in a given triggered event), like earthquakes, scale as a power-law or other heavy-tailed distributions. If confirmed, this could have important implications for risk assessment and erosion modelling in a given area. In our second set of analyses, we find that for short antecedent rainfall periods, the minimum amount of rainfall necessary to trigger landslides varies considerably with the intensity of the landsliding (DL and Sevent); whereas for long antecedent periods the magnitude is largely independent of the cumulative amount of rainfall, and the largest values of landslide intensity are always preceded by abundant rainfall. Further, the analysis of the rainfall trend suggests that the trigger of landslides in the study area is related to seasonal rainfall. Copyright © 2010 John Wiley & Sons, Ltd. [source]


Trace Metals in Anaerobic Granular Sludge Reactors: Bioavailability and Dosing Strategies

ENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 3 2006
H. Zandvoort
Abstract The trace metal dynamics in anaerobic granular sludge bed reactors and their influence on reactor performance is reviewed in this paper. An insight into the metal dynamics is required from a practical point of view in order to be able to early recognize limitations for essential trace elements, viz., to know when dosing of these elements is required in full-scale anaerobic bioreactor applications. Further such knowledge is indispensable for a rational dosage of these metals, e.g., to ensure maximum substrate conversion rates and to prevent disturbances in reactor performance using a minimum amount of metals. Therefore, the retention, accumulation and release of trace metals in anaerobic granular sludge and the factors affecting these processes need to be known. [source]


Unpacking the effect of IT capability on the performance of export-focused SMEs: a report from China

INFORMATION SYSTEMS JOURNAL, Issue 4 2008
Man Zhang
Abstract., Export-focused small and medium-sized enterprises (SMEs) in China face a number of barriers to success, two primary ones being the liability of foreignness and resource scarcity. In order to transcend these challenges and be able to survive/prosper in the hypercompetitive international market, where players include large resourceful multinational organizations with experience in varied national contexts, these firms need to develop different organizational capabilities. In this paper, we specifically examine the role of a key organizational capability , information technology (IT) capability , and its different dimensions, in determining performance of export-focused SMEs in China. Our study reveals that IT capability has a positive impact on such firms' performance. This finding indicates the need for their owners/managers to invest in IT capability. Further, the study also highlights specific sub-dimensions of IT capability that export-focused Chinese SMEs should (or should not) develop, so as to derive maximum performance-related gains for the minimum amount spent on IT. [source]


Compomers in restorative therapy of children: a literature review

INTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 1 2007
NORBERT KRÄMER
Objective., The restoration of carious primary teeth plays an underestimated role in paediatric dentistry. This is astonishing for many reasons, not least because many new materials have been introduced in recent years. New or modified techniques and materials, with better aesthetics and flexural properties, allow minimally invasive treatment. A transfer of techniques between different dentitions, however, may be problematic because of both micromorphological differences and compliance. Therefore, this paper deals with options for restoring primary teeth and the early stages of the mixed dentition using polyacid-modified composites, the so-called compomers. Methods., Medline and Embase were scanned from 1990 through 2006. Furthermore, a hand-search of nonlisted but peer-reviewed papers was performed. The search items were compomer*, dent*, primary* and deciduous*, which identified 109 relevant publications. Conclusions., Based on high clinical success rates, compomers are now an effective alternative to other materials for restorative therapy in the anterior and posterior primary teeth. A minimum amount of compliance is still mandatory in order to allow for a few minutes of adhesive pretreatment and layering without contamination. If this is not the case, compomers make no sense. Stainless steel crowns are still the most effective from of restoration for severely decayed primary molars. [source]


Revisiting Oligopolistic Reaction: Are Decisions on Foreign Direct Investment Strategic Complements?

JOURNAL OF ECONOMICS & MANAGEMENT STRATEGY, Issue 3 2002
Keith Head
Knickerbocker (1973) introduced the notion of oligopolistic reaction to explain why firms follow rivals into foreign markets. We develop a model that incorporates central features of Knickerbocker's story,oligopoly, uncertainty, and risk aversion,to establish the conditions required to generate follow-the-leader behavior. We find that rival foreign investment will make risk-neutral firms less inclined to move abroad once its rivals have done so. We show that Knickerbocker's prediction relies on risk aversion and derive an expression for the minimum amount of risk aversion needed to generate oligopolistic reaction. [source]


In Vitro,Potential of,Ascophyllum nodosum,Phenolic Antioxidant-Mediated ,-Glucosidase and ,-Amylase Inhibition

JOURNAL OF FOOD SCIENCE, Issue 3 2010
E. Apostolidis
ABSTRACT:,Ascophyllum nodosum,is a brown seaweed that grows abundantly in the Northeast coastal region. In this study, the potential of,A. nodosum,for type 2 diabetes management through antioxidant-mediated ,-glucosidase and ,-amylase inhibition was investigated. After the initial screening of 4 locally harvested seaweeds,,A. nodosum,was chosen for its highest phenolic content and was subjected to water extraction. Among extraction ratios of 50 g to 100 to 1000 mL at room temperature, 50 g/400 mL yielded the highest phenolic content of 4.5 mg/g wet weight. For evaluation of extraction temperature ranging from 20 to 80 °C, 50 g/400 mL was chosen as a minimum amount of extractant. Among temperatures studied, extraction at 80 °C resulted in the highest total phenolic contents (4.2 mg/g wet weight). All extracts had similar levels of antioxidant activity in the range of 60% to 70% in terms of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. The 80 °C extract had the highest ,-glucosidase and ,-amylase inhibitory activity with IC50 of 0.24 and 1.34 ,g phenolics, respectively, compared to the IC50 of acarbose, reference inhibitor, being 0.37 and 0.68 ,g. The results show that fresh,A. nodosum,has strong ,-glucosidase and mild ,-amylase inhibitory activities that correlated with phenolic contents. This study suggests a nutraceutical potential of,A. nodosum,based on phytochemical antioxidant and antihyperglycemia activities. [source]


Survey of endoscopic ultrasonographic practice and training in the Asia-Pacific region

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 8 2006
Khek Yu Ho
Abstract Background:, Little is known about the current status of endoscopic ultrasonography (EUS) training in the Asia,Pacific region. The aim of the present study was to assess EUS practice and training in the Asia,Pacific region and seek to identify areas where the development of EUS expertise could be further enhanced. Methods:, A direct mail survey was sent out to 87 practising endosonographers in various parts of the Asia,Pacific region outside of Japan. They were asked to report on their prior training, utilization of EUS, and EUS training in their country. Results:, The respondents (n = 71) were mostly young (median age 40 years), male (97%), practising in academia (36.6%) or public hospitals (50.7%) and fairly experienced (median 5 years) in EUS practices; they had performed a median of 500 procedures in their career. Among them, 49.3% were self-taught. Only 22.5% and 21.1% had undergone formal overseas fellowship lasting ,6 months, and local gastrointestinal fellowships of various durations, respectively. Fifty-six percent were currently involved in EUS teaching. Most (90%) thought that a formal EUS training fellowship is necessary for acquiring acceptable competence and there should be a minimum number (median 100) of supervised procedures performed and minimum amount of time (median 6 months) spent on training. Conclusions:, Although EUS practitioners in the Asia,Pacific region were not behind their European or US counterparts in hands-on experience, the lack of formal EUS training programs and opportunities remains an area of concern. For the region to increase EUS utilization, the current shortage of training opportunities needs to be addressed. [source]


A time-dependent multiphysics, multiphase modeling framework for carbon nanotube synthesis using chemical vapor deposition

AICHE JOURNAL, Issue 12 2009
Mahmoud Reza Hosseini
Abstract A time-dependent multiphysics, multiphase model is proposed and fully developed here to describe carbon nanotubes (CNTs) fabrication using chemical vapor deposition (CVD). The fully integrated model accounts for chemical reaction as well as fluid, heat, and mass transport phenomena. The feed components for the CVD process are methane (CH4), as the primary carbon source, and hydrogen (H2). Numerous simulations are performed for a wide range of fabrication temperatures (973.15,1273.15 K) as well as different CH4 (500,1000 sccm) and H2 (250,750 sccm) flow rates. The effect of temperature, total flow rate, and feed mixture ratio on CNTs growth rate as well as the effect of amorphous carbon formation on the final product are calculated and compared with experimental results. The outcomes from this study provide a fundamental understanding and basis for the design of an efficient CNT fabrication process that is capable of producing a high yield of CNTs, with a minimum amount of amorphous carbon. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]


On the Cost of Adverse Selection in Individual Annuity Markets: Evidence From Singapore

JOURNAL OF RISK AND INSURANCE, Issue 2 2002
Wai Mun Fong
New evidence is presented on the cost of adverse selection in individual annuity markets using Singapore data. The Singapore annuity market is an interesting setting to examine the cost of adverse selection for three reasons. First, unlike many Western countries, the Singapore government provides very limited public financial assistance for retirees. Second, while social security contributions mandated under the Central Provident Fund (CPF) result in a high forced savings rate, a large proportion of CPF savings, are used up for housing. Third, to ensure that retirees have sufficient funds to meet basic needs, individuals who reach age 55 are required to set aside a minimum amount of their CPF savings, which can be withdrawn at age 62. The CPF Board allows various options for investing the minimum sum, but the most attractive option is to purchase an annuity. The institutional setting in Singapore in effect provides insurers with a large captive market for annuities. It is conjectured that this should be reflected in a significantly lower cost of adverse selection for annuities sold in Singapore as compared with other countries. The results herein, using data for CPF-approved insurers, are strongly consistent with this conjecture. On average, money's worth of annuities is higher than annuities sold to a similar age-gender mix in the United States, United Kingdom, and Australia. Adverse selection accounts for less than 13 percent of the cost of longevity insurance compared to 30,50 per- cent documented in many previous studies. These results suggest that one way to resolve the adverse selection problem is to adopt a universal individual defined contribution pension scheme that mandates or provides strong incentives for retirees to purchase annuities. [source]


Modified radiofrequency-assisted liver resection: A new device

JOURNAL OF SURGICAL ONCOLOGY, Issue 3 2007
Dimitris Zacharoulis MD
Abstract Background Radiofrequency ablation (RF) is emerging as new therapeutic method for the management of hepatic tumors. So far the RF-assisted hepatectomy has been described using an electrode initially designed for ablation of unresectable tumors. Herein, we describe a new technique for liver resection using a bipolar radiofrequency device. Method Ten patients undergo liver resection using a bipolar radiofrequency device. A minimal zone of desiccation around the tumor is created between pairs of opposing electrodes as a result of a minimum amount of energy released. This coagulated plane can be divided with a scalpel. Results The liver parenchyma was divided with minimal blood loss. No intensive care unit admission was needed. There was no postoperative biliary leak or any other septic complication. Conclusion The technique is safe and feasible, simplifies liver resection and appears to be associated with minimal morbidity and maximum liver parenchyma preservation. J. Surg. Oncol. 2007;96: 254,257. © 2007 Wiley-Liss, Inc. [source]


Nutrient requirements of ephemeral plant species from wet, mesotrophic soils

JOURNAL OF VEGETATION SCIENCE, Issue 3 2001
Emiel; Brouwer
van der Meijden (1996) Abstract. Nanocyperion plant communities occur on wet, more or less nutrient-poor and sparsely vegetated soils in temperate climates and are characterized by tiny, very shortlived plant species. Most of these have become locally extinct. It is generally assumed that drainage and eutrophication were the most important reasons for this decrease. However, chemical analysis of soil pore water from plots on growth sites of these ephemerals showed that phosphorus availability was relatively high. In a greenhouse experiment, the growth of ephemeral species was strongly limited by the amount of available phosphorus, whereas there was little or no limitation to the growth of other plant species from this habitat. At low phosphorus concentrations, the ephemeral species reached their reproductive phase within the same period, but showed a strong reduction in the amount of flowers that were produced. We concluded that ephemeral species in particular require a minimum amount of phosphorus for reproduction. Other species on nutrient-poor, wet soils have a longer life span and can postpone flowering in nutrient-poor soils. In contrast to other short-lived plant species from the same habitat, the growth of ephemeral species was barely stimulated by enhanced nitrogen availability. Apparently, the ephemerals are adapted to low nitrogen concentrations. The occurrence on nitrogen-poor and relatively phosphorus-rich soils suggests that this community may be very sensitive to nitrogen deposition. Reduced phosphorus availability below the minimum requirements of ephemerals, for example after acidification or the exclusion of human activities, has possibly contributed to the decrease of ephemeral plant species. [source]


Development and validation of new model for microvascular transplantation of epiphyseal plate allografts with minimal adjoining epiphyseal and metaphyseal bone

MICROSURGERY, Issue 2 2003
M.Sc., Peter W. Bray M.D.
A model for the free allograft microvascular transplantation of rabbit proximal tibial epiphyseal plate allografts was developed, validated, and tested in an in vivo animal model. Transplants contained the minimum amount of adjacent epiphyseal and metaphyseal bone compatible with preservation of the epiphyseal-plate vascular supply, as determined by corrosion casting. Perfusion to this graft was evaluated quantitatively using radioactive microspheres, and qualitatively using India-ink injection. Female New Zealand White rabbits at 12 weeks of age were utilized. Vascularized transplantation of epiphyseal plate allografts was performed either into a defect of matched size in the iliac crest or into a soft-tissue pocket without bone contact. Cyclosporine A immunosuppression (CSA) was administered daily for 6 weeks. Two control groups underwent identical surgical procedures, but had no postoperative immunosuppression. Epiphyseal plates both with and without bone contact, in rabbits immunosuppressed postoperatively with CSA, demonstrated longitudinal growth and preserved viability as determined by positive bromodeoxyuridine uptake. Control epiphyseal plates transferred without postoperative immunosuppression were uniformly nonviable. This new model has value as a basis for further studies into the clinical applicability of isolated epiphyseal-plate transplants. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:153,163 2003 [source]


Economical Advantages of Low-Pressure Plasma Polymerization Coating

PLASMA PROCESSES AND POLYMERS, Issue 6 2005
Hirotsugu Yasuda
Abstract Summary: Low-pressure plasma polymerization coating, as described in this paper, is an ultimately green process that uses a minimum amount of substances and produces a minimum amount of effluent and hence does not require an environmental remediation process. The super-green aspect of the processing entirely changes the equation for the viability of the process in industrial applications. The main hampering factors for the low-pressure processes are 1) psychological fear of vacuum processes, 2) relatively high initial equipment costs, and 3) a lack of adequate cost estimate for the entire process. In many cases, the first two factors are enough for planners to shy away from this promising technology. However, when one examines the overall cost of processing as a whole, the cost of initial equipment often is not the decisive factor. Such cases are presented in the nano-film coating applied in corrosion protection of aluminum alloys, steel, and surface-state modification of contact lenses. The benefits of environmental friendliness, non-hazardous processing and superior performance of products that can be achieved only by low-pressure plasma polymerization coatings are more than enough to compensate the initial cost of the equipment. For nanofilm (20 nm) coatings, the most expensive annual operation cost is for wastewater treatment, which is much more than the initial cost of vacuum plasma polymerization reactor. [source]


Simultaneous determination of endogenous deoxynucleotides and phosphorylated nucleoside reverse transcriptase inhibitors in peripheral blood mononuclear cells using ion-pair liquid chromatography coupled to mass spectrometry

PROTEOMICS - CLINICAL APPLICATIONS, Issue 10-11 2008
Leon Coulier
Abstract Nucleoside reverse transcriptase inhibitors (NRTIs) are activated intracellularly to their triphosphate (TP) form, which compete with endogenous deoxynucleotide-triphosphates (dNTP) as substrate for HIV reverse transcriptase. The activity of NRTIs is thus described by the NRTI-TP-to-dNTP ratio in relevant cell types. Therefore, we developed an ion-pair (IP) LC-MS method for the simultaneous analysis of the mono-, di-, and TP forms of NRTIs and endogenous deoxynucleosides in peripheral blood mononuclear cells (PBMC). The IP-LC method was applied on an IT mass spectrometer using the MS-mode as well as on a triple quadrupole mass spectrometer using the MS/MS mode. The MS/MS approach on the triple quadrupole mass spectrometer demonstrated the best clinical applicability due to its higher sensitivity. The LOD (minimum amount on column) were 25,fmol for the TP forms of zidovudine, lamivudine, and stavudine, as well as for their endogenous dNTP counterparts. The linearity (R2) of the calibration curves were>0.99. The obtained LOD readily allow for clinical applications using just one million PBMC obtained from HIV-infected patients under therapy. [source]


Highly efficient catalytic system for electrophilic amination of arylzinc reagents

APPLIED ORGANOMETALLIC CHEMISTRY, Issue 1 2010
Tahir Da, kapan
Abstract The effect of catalyst on the yield of amine in the amination of three classes of arylzinc reagents with acetone oxime O -tosylate was investigated. Since they allowed the preparation of arylamines in excellent yields in the presence of a minimum amount of copper (I) or copper (II) compounds, the catalytic systems using copper (I) or copper (II) combined with a P-, N- or S-donor ligand were revealed to be the best catalysts for the electrophilic amination of arylzinc reagents with acetone oxime O -tosylate in the presence of DMPU. Copyright © 2009 John Wiley & Sons, Ltd. [source]


Simulation and Optimization of an Adiabatic Multi-Bed Catalytic Reactor for the Oxidation of SO2

CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 1 2007
A. Nodehi
Abstract A software package was developed for the simulation and optimization of a multi-bed adiabatic reactor for the catalytic oxidation of SO2, using a heterogeneous plug flow model. The orthogonal collocation (OC) technique with up to eight collocation points was used for the solution of a nonlinear, two-point boundary value differential equation for the catalyst particle, and it was shown that the use of the OC technique with two collocation points can describe the system well. Because of the nonlinear behavior of the effectiveness factor along the bed, optimal catalyst distribution between the beds and corresponding inlet temperatures were determined by two methods, including: the use of (1) intrinsic or (2) actual rate of reaction in the optimization criteria. The results showed that for the second case, the minimum amount of the catalyst can be reached at lower temperatures, the amount of catalyst required is always less, and the number of beds is greater than or equal to that of the first case. [source]


Preconcentration and Determination of Copper(II) Using Octadecyl Silica Membrane Disks Modified by 1,5-Diphenylcarhazide and Flame Atomic Absorption Spectrometry

CHINESE JOURNAL OF CHEMISTRY, Issue 11 2007
Ali MOGHIMI
Abstract A simple and reproducible method for the rapid extraction and determination of trace amounts of copper(II) ions using octadecyl-bonded silica membrane disks modified by 1,5-diphenylcarbazide (DPC) and atomic absorption spectrometry was presented, which was based on complex formation on the surface of the ENVI-18 DISKTM disks followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution was efficient and quantitative. The effect of potential interfering ions, pH, ligand amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to be about 1000 mL providing a preconcentration factor of 400. The maximum capacity of the disks was found to be (255±5) µg for Cu2+, and the limit of detection of the proposed method was 5 ng per 1000 mL. The method was applied to the extraction and recovery of copper in different water samples. [source]