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The End of Cheap Uranium  [PDF]
Michael Dittmar
Physics , 2011,
Abstract: Historic data from many countries demonstrate that on average no more than 50-70% of the uranium in a deposit could be mined. An analysis of more recent data from Canada and Australia leads to a mining model with an average deposit extraction lifetime of 10+- 2 years. This simple model provides an accurate description of the extractable amount of uranium for the recent mining operations. Using this model for all larger existing and planned uranium mines up to 2030, a global uranium mining peak of at most 58 +- 4 ktons around the year 2015 is obtained. Thereafter we predict that uranium mine production will decline to at most 54 +- 5 ktons by 2025 and, with the decline steepening, to at most 41 +- 5 ktons around 2030. This amount will not be sufficient to fuel the existing and planned nuclear power plants during the next 10-20 years. In fact, we find that it will be difficult to avoid supply shortages even under a slow 1%/year worldwide nuclear energy phase-out scenario up to 2025. We thus suggest that a worldwide nuclear energy phase-out is in order. If such a slow global phase-out is not voluntarily effected, the end of the present cheap uranium supply situation will be unavoidable. The result will be that some countries will simply be unable to afford sufficient uranium fuel at that point, which implies involuntary and perhaps chaotic nuclear phase-outs in those countries involving brownouts, blackouts, and worse.
Fast, cheap and somewhat in control
Adam P Arkin, Daniel A Fletcher
Genome Biology , 2006, DOI: 10.1186/gb-2006-7-8-114
Abstract: The natural world around us is not quite so natural. Over many generations, societies have engaged in a struggle to mold nature to serve the needs, real and perceived, of their members. From cultivating grains to mining coal, we have sought to address local and global demands for food, shelter, health, and convenience through technology guided by science. One of the earliest and most profound of human engineering inventions was biotechnology in the form of farming, starting about 12,000 years ago. This was later transformed into a true domestication of animal and plant species that might be defined as "genetic alteration through conscious or unconscious selection" [1]. It provided the key foundation for the spread and stability of human societies and has become one of the most central and longest-lived sciences there is. In more modern times, a scientific/rational basis for domestication and control of biological organisms has been sought both to make breeding organisms for human purposes quicker and more successful, and to limit the spread of infectious disease and other invasive species. The eradication of smallpox and the near-eradication of polio stand as reminders of how advanced medical, industrial and social engineering can change the health of an entire world. The precision of molecular biology has led to a whole new form of domestication and industry. Launched by the first mass production of a human protein (somatostatin) in bacteria, industrial genetic engineering became one of the most transforming industries of the 20th century [2]. After the introduction of genetically engineered herbicide- and insect-resistant crops in 1995, genetically engineered maize is now more than 20% of the US crop, and approximately 80% of the US soybean crop is now genetically engineered [3].Engineered biological systems are being used to address a wide variety of society's needs. Examples include the production of insulin and more than 200 other biopharmaceuticals and countle
Urban segregation with cheap and expensive residences  [PDF]
M. A. Sumour,A. H. El-Astal,M. A. Radwan,M. M. Shabat
Physics , 2007, DOI: 10.1142/S0129183108012406
Abstract: In this paper we study urban segregation of two different communities A and B, poor and rich, distributed randomly on finite samples, to check cheap and expensive residences. For this purpose we avoid the complications of the Schelling model which are not necessary and instead we use the Ising model on 500 x 500 square lattice, which give similar results, with random magnetic field at lower and higher temperatures (kT/J = 2.0, 99.0) in finite times equal to 40, 400, 4000 and 40,000. This random-field Ising magnet is a suitable model, where each site of the square lattice carries a magnetic field h which is randomly up (expensive) or down (cheap). The resulting addition to the energy prefers up spins on the expensive and down spins on the cheap sites. Our simulations were carried out using a 50-lines FORTRAN program. We present at a lower temperature (2.0) a time series of pictures, separating growing from non-growing domains. A small random field (h = +- 0.1) allows for large domains, while a large random field (h = +- 0.9) allows only small clusters. At higher temperature (99.0) we could not obtain growing domains.
Insecticidal Activity of the Aqueous Extracts of Four Under-utilized Tropical Plants as Protectant of Cowpea Seeds from Callosobruchus maculatus Infestation  [PDF]
O.M. Obembe,J. Kayode
Pakistan Journal of Biological Sciences , 2013,
Abstract: The test plants species, namely Crotaria retusa, Hyptis suaveolens, Ricinus communis and Tithonia diversifolia were extracted with water. The extracts were evaluated on Callosobruchus maculatus for mortality, oviposition and adult emergence effects. The long-term protectant ability and viability were also investigated. The results showed that the aqueous extracts from T. diversifolia were most effective on C. maculatus, followed by extract from Ricinus communis. The least potent extracts were those extracted from Crotalaria retusa and Hyptis suaveolens. Also, the extracts considerably reduced oviposition by C. maculatus. Extracts from T. diversifolia and R. communis drastically reduced infestation and subsequence damage of the treated cowpea seeds for a period of three months. Most of the treated seeds germinated after 90 days storage period. The results from this study revealed that aqueous extracts from all the four plants species were effective in controlling cowpea bruchid, C. maculatus and could serve as an alternative to synthetic insecticides for protection of stored cowpea seeds against bruchids.
Optimization of Protectant, Salinity and Freezing Condition for Freeze-Drying Preservation of Edwardsiella tarda Optimization of Protectant, Salinity and Freezing Condition for Freeze-Drying Preservation of Edwardsiella tarda  [PDF]
YU Yongxiang,ZHANG Zheng,WANG Yingeng,LIAO Meijie,LI Bin,XUE Liangyi
- , 2017,
Abstract: Novel preservation condition without ultra-low temperature is needed for the study of pathogen in marine fishes. Freeze-drying is such a method usually used for preservation of terrigenous bacteria. However, studies using freeze-drying method to preserving marine microorganisms remain very limited. In this study, we optimized the composition of protectants during the freeze-drying of Edwardsiella tarda, a fish pathogen that causes systemic infection in marine fishes. We found that the optimal composition of protectant mixture contained trehalose(8.0%), skim milk(12.0%), sodium citrate(2.0%), serum(12.0%) and PVP(2.0%). Orthogonal and interaction analyses demonstrated the interaction between serum and skim milk or sodium citrate. The highest survival rate of E. tarda was observed when the concentration of Na Cl was 10.0, 30.0 and between 5.0 and 10.0 g L~(-1) for preparing TSB medium, E. tarda suspension and protectant mixture, respectively. When E. tarda was frozen at-80℃ or-40℃ for 6 h, its survival rate was higher than that under other tested conditions. Under the optimized conditions, when the protectant mixture was used during freeze-drying process, the survival rate(79.63%–82.30%) of E. tarda was significantly higher than that obtained using single protectant. Scanning electron microscopy(SEM) image indicated that E. tarda was embedded in thick matrix with detectable aggregation. In sum, the protectant mixture may be used as a novel cryoprotective additive for E. tarda
Microreboot -- A Technique for Cheap Recovery  [PDF]
George Candea,Shinichi Kawamoto,Yuichi Fujiki,Greg Friedman,Armando Fox
Computer Science , 2004,
Abstract: A significant fraction of software failures in large-scale Internet systems are cured by rebooting, even when the exact failure causes are unknown. However, rebooting can be expensive, causing nontrivial service disruption or downtime even when clusters and failover are employed. In this work we separate process recovery from data recovery to enable microrebooting -- a fine-grain technique for surgically recovering faulty application components, without disturbing the rest of the application. We evaluate microrebooting in an Internet auction system running on an application server. Microreboots recover most of the same failures as full reboots, but do so an order of magnitude faster and result in an order of magnitude savings in lost work. This cheap form of recovery engenders a new approach to high availability: microreboots can be employed at the slightest hint of failure, prior to node failover in multi-node clusters, even when mistakes in failure detection are likely; failure and recovery can be masked from end users through transparent call-level retries; and systems can be rejuvenated by parts, without ever being shut down.
Protectant, insecticidal and antimicrobial potentials of Dalbergia saxatilis Hook f. (fabaceae)
SK Okwute, R Onyia, C Anene, OP Amodu
African Journal of Biotechnology , 2009,
Abstract: The protectant, insecticidal and antimicrobial potentials of the Nigerian plant, Dalbergia saxatilis (Fabaceae) were investigated. The dried powdered leaves of D. saxatilis were established as a control agent for the cowpea pest, Callosobruchus maculatus. Damage was drastically reduced when cowpea seeds were treated with dry powdered leaves of D. saxatilis. Doses of 0.75 g/150 seeds and above significantly reduced crop damage, oviposition and larval development without affecting the viability of the seeds. Similarly, the crude 95% ethanol extract and the aqueous methanol and hexane fractions of the bark extract showed insecticidal activity against adult mosquitoes at 0.2% concentration in ethyl acetate. The crude 95% ethanol extracts of the leaves and bark were screened against six pathogenic microorganisms (ATCC). While the leaves extract was active against only Staphylococcus aureus at minimum inhibition concentration (MIC) 1000 mg/ml, the bark extract displayed broad and interesting antimicrobial spectra. The bark extracts gave activity at MICs 250, 125, 1000 and 1000 mg/ml against S. aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa, respectively. The above properties demonstrate the great potentials of D. saxatilis for use in agriculture and medicine. The relevance of bioassay-guided fractionation in ensuring consistency and enhancement of efficacy and quality of phyto-medicines and bio-pesticides is discussed.
Phytochemical Constituents and Antimicrobial and Grain Protectant Activities of Clove Basil (Ocimum gratissimum L.) Grown in Nigeria
International Journal of Plant Research , 2012, DOI: 10.5923/j.plant.20120201.08
Abstract: Ocimum gratissimum Linn (Lamiaceae) is an herbaceous plant reputed for many medicinal and agronomic practices amongst Nigerian peasant farmers. O. gratissimum was investigated for antimicrobial activity against ten micro-organisms and for grain protectant activity against Callosobrochus maculatus. The phytocontituents of the aerial part of O. gratissimum were extracted with 95% ethanol using the percolation method. The crude ethanol extracted was further fractionated into hexane, chloroform and methanol fractions. The fractions obtained were screened for phytoconstiteunts, antimicrobial and grain protectant properties. Result showed that hexane fraction exhibited the highest antimicrobial activity against Vibrio cholera and Klebsiella pneumonia. Similarly hexane fraction also showed the highest grain protectant activity. The other extracts of the O. gratissimum did not significantly inhibit both bacterial growth and grain infestation. However, the methanol fraction contains phytocompounds such as phenolic compounds associated with antioxidant properties. The study shows that O. gratissimum extractants are potential sources of antimicrobial and preservative agents.
A Simple Laboratory Prescreen for Plants with Grain Protectant Effects Against the Maize Weevil; Sitophilus zeamais (Mots) (Coleoptera: Curculionidae)
S.T. Arannilewa
Agricultural Journal , 2013,
Abstract: A simple bioassay technique to assess pulverized indigenous plant materials for ability to protect maize grains from damage by weevils during storage, was employed. Of the 9 plants that were screened, Zanthoxylum xanthoxyloides (Lam.) Waterm. (Rutaceae), Aristolochia ringens Vahl. (Aristolochiaceae) and Morinda lucida Linn. (Rubiaceae) showed best protectant effects on adult toxicity, adult emergence and Weevil Perforation Index (WPI). The details of the bioassay procedure used and the results obtained are reported.
"Intelligent" controllers on cheap and small programmable devices  [PDF]
Cédric Join,Frédéric Chaxel,Michel Fliess
Mathematics , 2013,
Abstract: It is shown that the "intelligent" controllers which are associated to the recently introduced model-free control synthesis may be easily implemented on cheap and small programmable devices. Several successful numerical experiments are presented with a special emphasis on fault tolerant control.
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