Dispersive shock waves in the Kadomtsev-Petviashvili and Two Dimensional Benjamin-Ono equations

Dispersive shock waves (DSWs) in the Kadomtsev-Petviashvili (KP) equation and two dimensional Benjamin-Ono (2DBO) equation are considered using parabolic front initial data. Employing a front tracking type ansatz exactly reduces the study of DSWs in two space one time (2+1) dimensions to finding DSW solutions of (1+1) dimensional equations. With this ansatz, the KP and 2DBO equations can be exactly reduced to cylindrical Korteweg-de Vries (cKdV) and cylindrical Benjamin-Ono (cBO) equations, respectively. Whitham modulation equations which describe DSW evolution in the cKdV and cBO equations are derived in general and Riemann type variables are introduced. DSWs obtained from the numerical solutions of the corresponding Whitham systems and direct numerical simulations of the cKdV and cBO equations are compared with excellent agreement obtained. In turn, DSWs obtained from direct numerical simulations of the KP and 2DBO equations are compared with the cKdV and cBO equations, again with remarkable agreement. It is concluded that the (2+1) DSW behavior along parabolic fronts can be effectively described by the DSW solutions of the reduced (1+1) dimensional equations.Comment: 25 Pages, 16 Figures. The movies showing dispersive shock wave propagation in Kadomtsev-Petviashvili II and Two Dimensional Benjamin-Ono equations are available at https://youtu.be/AExAQHRS_vE and https://youtu.be/aXUNYKFlke

多官能性シロキサンモノマーに基づくハイブリッドネットワークポリマーに関する研究

要約のみTohoku University三ツ石方也課

Enhanced lactic acid production by strain development and by a novel biofilm reactor

Chemical mutagenesis with ethyl methanesulfonate followed by selective culturing was used to develop strains of Lactobacillus delbrueckii that tolerated increased lactic acid concentrations while continuously producing the acid. In stirred-tank-batch fermentations, mutant DP3 in 12% glucose, 3% yeast extract-mineral salt-oleic acid medium produced lactic acid more than four times faster than the wild type. Mutant DP3 produced 117 g/l lactic acid compared with 67 g/l for the wild type. Mutant DP3 exhibited faster specific growth rates, shorter lag phases, greater lactic acid fields, and better lactic acid tolerance than the wild type. Mutant DP3 was stable for over 1.5 years (stored freeze dried). Mutants with enhanced lactic acid-producing capacity were obtained each time the strain development procedure was employed;Combinations of lactobacilli and biofilm-forming bacteria were evaluated in continuous fermentations for lactic acid production using various supports. Twelve different bacteria, including species of Bacillus, Pseudomonas, Streptomyces, Thermoactinomyces, and Thermomonospora, were tested for biofilm-forming capabilities. Solid supports that were evaluated in either batch or continuous fermentations were pea gravels, porcelain berl saddles, 3M-macrolite ceramic spheres, and polypropylene (pp) mixed with 25% various agricultural materials (e.g. corn starch, oat hulls) and extruded to form chips. The best biofilm formation was observed with Pseudomonas fragi, Streptomyces viridosporus T7A, and Thermoactinomyces vulgaris. Biofilm formation on the pp-composite chips was detected at harvest by chip clumping and gram-staining. Lactic acid bacteria used in the fermentations were Lactobacillus amylophilus, Lactobacillus casei, and Lactobacillus delbrueckii mutant DP3. S. viridosporus T7A and L. casei on pp-composite chips were the best combination of those tested. In 25-ml continuous fermentations, biofilm reactors produced 10 to 14 g/l lactic acid at a flow rate of 0.24 ml/min, whereas 4.5 g/l of lactic acid was produced by the suspension culture. Furthermore, production rates that were two to five times faster than those of the suspension culture were observed for the pure- and mixed-culture bioreactors. Also, lactic acid concentrations and production rates were consistently higher in mixed-culture than in pure-culture fermentations on pp-composite chips

Drexel University

We present a 3D matching framework based on a many-to-many matching algorithm that works with skeletal representations of 3D volumetric objects. We demonstrate the performance of this approach on a large database of 3D objects containing more than 1000 exemplars. The method is especially suited to matching objects with distinct part structure and is invariant to part articulation. Skeletal matching has an intuitive quality that helps in defining the search and visualizing the results. In particular, the matching algorithm produces a direct correspondence between two skeletons and their parts, which can be used for registration and juxtaposition. 1

Densıty stage tendıng ın orıental spruce (picea orientalis (l.) link.) stands

Bu araştırma, Maçka Orman İşletmesi Kapuköy yöresi ormanlarında değişik zamanlarda gençleştirilmiş ve toplam olarak 15 hektarı bulan ladin sıklıklarında yapılmıştır. Sistematik örnekleme ile belirlenen 60 noktaya en yakın beş birey üzerinde 1.30 m deki çap, boy, yaş ve dört yönde en uzun yan dal uzunlukları saptanarak bu verilere göre hazırlanan 1.30 m çap - tepe tacı izdüşüm alanı ve boy - tepe tacı izdüşüm alanı grafiklerinden yararlanılarak iki tablo geliştirilmiştir. Bunlardan biri, 1 cm’lik çap kademelerine göre, diğeri de 0.50 m lik boy kademelerine göre bir bireyin kapladığı ortalama alan ve bakım yapıldıktan sonra hektarda bulunması gereken birey sayısını göstermektedir. Bu çalışma ile, tüm ladin sıklıklarında 4-6 yılda bir 3 kez bakım kesimleri yapılması ve kesimlerden sonra hektarda bırakılması gereken birey sayısının, ince çap kademesinden kalın çap kademesine doğru azalarak, göğüs yüksekliği çapı 1.00 cm olan meşcerelerde 9188 adet ve 14.00 cm olan meşcerelerde 970 adet olması gerektiği önerilmiştir. Öte yandan, bu sayının düşük boylardan yüksek boylara doğru azalarak 1.50 m boyundaki meşcerelerde 9900 adet ve 7.50 m boyundaki meşcerelerde 1302 adet olması gerektiği önerilmiştirThis research was done in density stage stands of of spruce in nearly 15 hectare in Kapuköy suburb of Maçka Forest District that regenerated in different periods. 1.30 m. diameter, height, age and the longest subterminal branches of the trees in four direction were established on five trees which were most closive to the 60 points that were confirmed by systematic sampling. 1.30 m. diameter-canopy square and height-canopy square graphics were formed according to these datums. By the help of these graphics two tables were developed. One of these table was arranged according to the diameter levels with 1 cm. periods and the other was arranged according to the height levels with 0.50 m. periods. Each table shows the covered area of each tree and the numbers of the trees that must be take place in an hectare after tending, according to the diameter levels and height levels. With this research, it is suggested that in density stage spruce stands, in every 4-6 years, there must be tending cuttings in three times and the numbers of the trees that must be take place in an hectare with a decrease from thin diameter stage to thick diameter stage must be 9188 in the stands that have 1 cm breast height and 970 in the stands that have 14 cm breast height. On the other hand it is suggested that with a decrease from low heights to high heigths the number of the trees that must be take place in an hectare must be 9900 in the stands that have 1.50 m height and 1302 in the stands that have 7.50 m height