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The ice-breaking process of the double-layer charge at a depth of 150 cm underwater is simulated by LS-DYNA. This paper analyzes the load type, shock wave pressure characteristics and propagation behavior of the double-layer charge during underwater explosion. By analyzing the impact of the shock wave pressure in the water under different charge intervals and time intervals on the shock wave pressure of the double charge, it is concluded that the peak pressure of the double charge explosion shock wave is jointly determined by the double charge. In this range, the second peak pressure value of the drug is greater than the pressure value of the first peak of the drug, and the attenuation is slow; the delay time of the upper charge has little effect on the peak pressure value of the shock wave in the water; the delay time is higher than that of the lower charge Initiation, at the same position, the total pressure peak of the shock wave formed by the delay of the upper charge is larger.

Fusarium wilt of banana, caused by Fusarium oxysporum f. sp. cubense (Foc), is one of the most destructive diseases of banana. Several experimental systems have been used to study banana—Foc interaction, including pot system and hydroponic system. In this study, an in vitro hydroponic system was developed for the growth of rooted banana plantlet. It was characterized by a filter-paper holder, which consisted of a cone cup and a round tube. Besides being used as supporting material and providing nutrients to the banana plantlet, the filter-paper holder was designed to create a humid and aerobic environment for root growth. It was observed that rooted plantlet could grow normally in inoculum-free nutrient solution for at least 8 weeks. In the following rejuvenation experiment, each plantlet was back-inoculated by adding spore suspension of a degenerated strain of Foc tropical race 4 (TR4) into nutrient solution. Three to four weeks after in vitro inoculation, the rejuvenated strain was isolated from the rhizome of the plantlet showing symptoms under sterile conditions. The results of pathogenicity test indicated that the third-generation rejuvenated strain had partially regained virulence, which was characterized by lower radial growth rate and higher level of sporulation compared with the degenerated strain. In contrast to previously reported hydroponic systems which applied to studies in relation to Fusarium wilt of banana, the one described here is a totally closed system. It is demonstrated that the in vitro hydroponic system can be used for studying the interaction between banana plantlet and Foc TR4. A novel in vitro hydroponic system is described, in which a rooted banana plantlet can grow normally for at least 8 weeks without an air pump. In vitro inoculation technique allows banana plantlet—Foc interaction without interference of other microorganisms.

In the process of breeding and selection of banana for resistance to Fusarium wilt, it is important to conduct an efficient resistance screening test by artificial inoculation with Fusarium oxysporum f. sp. cubense (Foc) Tropical Race 4. So far, there are two types of early bioassays for screening Musa genotypes against Foc: a greenhouse and an in vitro bioassay. The most commonly used greenhouse bioassay is a pot-based system followed by a hydroponic system. Here we describe an in vitro bioassay characterized by in vitro inoculation of rooted banana plantlets grown on medium consisting of half-strength MS macronutrients and MS micronutrients. The disease response and evaluation results obtained through this in vitro bioassay correlates with that from a greenhouse screen and/or field evaluation. Given the importance of in vitro cell and tissue culture techniques for banana (mutation) breeding, promising resistant clones could be screened directly. This in vitro bioassay is a totally contained system compared with greenhouse methods and does not require an acclimatization step, thereby improving banana breeding efficiency. The in vitro pre-screening protocol and bioassay for Fusarium wilt resistance presented here is fast, space-effective, and accurate.

In this chapter, the establishment of embryogenic cell suspension (ECS) cultures using immature male flowers of triploid banana (Musa AAA Cavendish subgroup cv. ‘Brazil’), followed by somatic embryogenesis and plantlet regeneration is described. Mutation induction is achieved by exposing the ECS to gamma irradiation with the dose of 80 Gy. The mutagenized cell population is transferred to solid long-term suspension culture medium for 96 h to recover from mutagen treatment shock, followed by somatic embryo induction and development medium containing 20% crude culture filtrates from Fusarium oxysporum f. sp. cubense (Foc). After 90 days, the somatic embryos that survive are transferred to the germination medium containing 25% crude culture filtrates. The surviving mature somatic embryos are transferred to rooting medium after the fourth subculture on the germination medium containing 50% crude culture filtrates. Before transplanting in a Foc infected field, the in vitro plantlets are acclimatized and screened for resistance to Foc using a pot-based greenhouse bioassay.

Foam as a soil conditioning agent has been extensively employed in earth pressure balanced (EPB) tunnel boring machines (TBM) to change the mechanical and hydraulic properties of soils for effective excavation. Foam stability is a critical parameter that influences the performance of foam and foam-conditioned soils. This paper examines foam stability under pressure through a novel foam generation – pressure chamber – foam capture testing system. A comprehensive suite of foam experiments was performed to examine the physical phenomenon of foam degradation and time-dependent foam properties under pressure. Testing results suggest that foam liquid loss is not an effective indicator for characterizing foam stability, while foam volume loss is a more appropriate measure of foam stability. Results also reveal that foam liquid drainage is significantly retarded at higher chamber pressure because foam bubbles are smaller and more uniform. Bubble size was not appreciably different in dry and wet foams.

Proper soil conditioning is critical for effective earth pressure balanced tunnel boring machine (EPBM) operation. Foam as a soil conditioner has been extensively used in EPBM tunneling to modify the excavated soil properties. A critical characteristic of foam-conditioned soil is stability, i.e., the ability to maintain the engineering properties throughout the residency time (30–90 min) in the mixing chamber. A comprehensive suite of experiments on foam-conditioned soil was conducted at both microscale and macroscale to investigate the fundamentals of foam-soil interaction and engineering properties of foam-conditioned soil. A foam-soil capture device and an optical microscope were used to capture bubble-grain images at a microscale under pressure. A pressurized testing chamber (PTC) was used to examine the stability of the mechanical properties of foam-conditioned soil. The compressibility, vane shear strength, pore pressure, and effective stress of foam-conditioned soil with elapsed time were obtained from the PTC test. The bubble-grain image analysis results reveal that foam is more stable when mixed with soil than by itself, indicating that soil particles help stabilize foam bubbles. Soil particles create a barrier to bubble coalescence and coarsening. The PTC test results show that the engineering properties of foam-conditioned soil remained constant over the 60-minute test duration. The results suggest that the accumulated “air bubble” at the top of the mixing chamber during EPBM tunneling is not due to the de-stabilization of foam bubbles when mixed with soil.

Precast, prestressed hollow-core (PHC) slabs are widely used in floor and roof decks because of their economic benefits. Because no shear reinforcement can be provided because of fabrication restraints, designers have to opt for deeper profile or filling PHC slab cores with concrete when the load demand exceeds the limited concrete shear capacity of PHC slabs. This research project is exploring an innovative technique for strengthening the web-shear capacity of PHC slabs by bonding external fiber-reinforced polymer (FRP) sheets along the internal perimeter of the slab voids. Experimental testing and numerical simulation on full-scale single web, I-shaped beam specimens cut out longitudinally from full-width hollow-core slabs have been performed during the first phase of this research to investigate the feasibility and effectiveness of this new technique. The influence of several design parameters, including the length and the width of the strengthened zone, the thickness of applied FRP sheets, and...

Prismatic members subjected to internal axial loads exist widely in engineering applications. Because the effects of internal loads and end loads on stability are quite different, the traditional effective length method is not applicable. Engineers require an efficient and convenient method for solving the stability problem of such members. A two-bar model is proposed to illustrate the concept that the effect of compressive axial loads on the stability of sway-inhibited columns can be understood as a negative lateral stiffness. After obtaining the expression of negative lateral stiffness, a relationship between end loads and internal loads can be established so that the internal loads can be considered equivalent to end loads. Then, the column subjected to internal loads can be analyzed as a normal column (without internal axial loads), and the critical buckling load can be obtained easily with the Euler formula. Eigenvalue buckling analyses were performed to examine the proposed method, and the c...

Foam generation in porous media and foam flow through pipes have been studied extensively to date as uncoupled processes. The coupled dynamics of foam generation and pipe flow, however, are comparatively understudied, despite their importance to industrial applications. We consider an experimental system that generates foam by flowing air and surfactant solution through a bead pack, after which the foam flows through a pipe to a downstream pressure chamber. We systematically vary the foam flow rate, bead diameter, bead pack length, pipe length, and chamber pressure. We measure the corresponding impact on flow pressures, densities, velocities, composition, and textures throughout the system, including direct measurements of bubble diameter distributions. We show that with the proper non-dimensionalization, the generator and pipe flows collapse to surprisingly simple friction-factor relationships. We also show that the mean foam bubble diameter exiting the bead pack decreases with increasing flow rate, up to a minimum value set by the pore length-scale K , where K is the bead pack permeability. We also explore the impact of foam texture and composition on the effective foam viscosities within the pipe. Finally, we show that foam properties evolve within the pipe, such that the pipe and bead pack play equally important roles in determining outlet foam properties.

Fusarium wilt of banana is caused by the soil-borne fungus Fusarium oxysporum f. sp. cubense (Foc). The fact that there are no economically viable biological, chemical, or cultural measures of controlling the disease in an infected field leads to search for alternative strategies involving activation of the plant's innate defense system. The mechanisms underlying systemic acquired resistance (SAR) are much less understood in monocots than in dicots. Since systemic protection of plants by attenuated or avirulent pathogens is a typical SAR response, the establishment of a biologically induced SAR model in banana is helpful to investigate the mechanism of SAR to Fusarium wilt. This paper described one such model using incompatible Foc race 1 to induce resistance against Foc tropical race 4 in an in vitro pathosystem. Consistent with the observation that the SAR provided the highest level of protection when the time interval between primary infection and challenge inoculation was 10d, the activities of defense-related enzymes such as phenylalanine ammonia lyase (PAL, EC 4.3.1.5), peroxidase (POD, EC 1.11.1.7), polyphenol oxidase (PPO, EC 1.14.18.1), and superoxide dismutase (SOD, EC 1.15.1.1) in systemic tissues also reached the maximum level and were 2.00-2.43 times higher than that of the corresponding controls on the tenth day. The total salicylic acid (SA) content in roots of banana plantlets increased from about 1 to more than 5 μg g⁻¹ FW after the second leaf being inoculated with Foc race 1. The systemic up-regulation of MaNPR1A and MaNPR1B was followed by the second up-regulation of PR-1 and PR-3. Although SA and jasmonic acid (JA)/ethylene (ET) signaling are mostly antagonistic, systemic expression of PR genes regulated by different signaling pathways were simultaneously up-regulated after primary infection, indicating that both pathways are involved in the activation of the SAR.

Exogenously applied GR24 affected somatic embryo formation and morphogenesis of strigolactone-deficient tomato mutant through cross-talk with auxins and cytokinins indicating involvement of SLs in the embryogenic process. Strigolactones (SLs) mediate the regulation of plant responses to the environment through cross-talk with other plant hormones, especially auxins. Auxins play a crucial role in coordinating the morphogenesis and development of plant reproductive organs, including the signal-transduction cascade leading to the reprogramming of gene-expression patterns before embryo formation. SLs' role in these processes is unknown, in contrast to their proven involvement in auxin transport and distribution. We used tomato cv. M82 and its SL-deficient mutant SL-ORT1 to study the influence of SLs on hormone profile in tomato roots and shoots, and their involvement in somatic embryogenesis (SE) and morphogenesis (adventitious root formation). The synthetic SL GR24 had different effects on SE of M82 and SL-ORT1, indicating that SLs influence the cytokinin-to-auxin ratio in tomato SE.

Over 50 years ago, banana export plantations in Panama were ruined by Fusarium wilt race 1 (Foc. R1) since the popular cultivar Gros Michel is susceptible to Foc. R1 [1]. Fortunately, the resistant cultivar Cavendish replaced Gros Michel as the world biggest commercial fruit after ten years’ research and development. Due to its good economic profit, banana industry develops very fast recently in China. Unfortunately, Fusarium oxysporum f. sp. cubense tropical race 4 (TR4) brought disaster to Cavendish plantation since 1996. Most of traditional banana planting zones of Guangdong and Hainan provinces were infected by Foc. TR4 to the end of 2009. In order to fight against Foc. TR4, here we tried to investigate the cost-benefit and disease resistance of six banana cultivars (Cavendish Baxijiao, Dajiao, Guangfen No. 1, Fenzha No. 1, Gongjiao, Haigongjiao) planted in China Foc. Zones. Comparisons were conducted on their economic characteristics, cost, benefit, as well as the advantage and disadvantage and their application in rota-tion. Generally, supposing the investment of $ 4400/ha, the banana plantation attains a good economic profit as $ 2200/ha. Rotation of these cultivars can maintain the biodiversity as well as improve the sustainable development of banana industry.

Litchi and longan are famous southern subtropical fruits in China. Besides closely related to each other taxonomically, litchi and longan share many similarities in origin, cultivation history and environmental requirements; furthermore, the developments of research on litchi and longan germplasm resources are somewhat similar and comparable. This paper reviews the literature on origin and distribution, collection and conservation, classification and identification, selection and breeding of litchi and longan germplasm resources in China. The classification of litchi and longan can be divided into three stages: classification based on morphological traits, classification by isozyme analysis and DNA markers. The expression of morphological traits is often affected by environmental conditions; the number of loci that isozyme analysis can examine is small, cultivars, which are closely related often have identical isozyme patterns. The limitations of classification based on morphological traits and isozyme analysis are then overcome by the utilization of molecular markers. At present, most new litchi and longan cultivars are selected from superior seedlings obtained after open-pollination or sport; germplasm with desirable characteristics such as aborted seeds, rather big-fruit and rather late-bearing have not been fully exploited. In order to achieve the goal of improving fruit quality and agronomic characteristics, it is suggested that additional studies of genetic diversity on litchi and longan germplasm should be carried out with more powerful markers such as SSR and ISSR; marker assisted selection (MAS) should be employed to improve litchi and longan's cross breeding efficiency.

Because loess underground erosion is one of the major engineering geological problems in loess areas of China, foundation loess of the Zichang-Yongping section of West-East Gas Pipelines is taken as the research object. The soil-water characteristic curve (SWCC) and hydraulic conductivity function (HCF) of samples have been obtained by laboratory tests, and on this basis, seepage field numerical simulations of loess foundation with and without the pipelines have been processed by the finite-element method. Critical groundwater seepage velocity of underground erosion and the relationship between groundwater seepage velocity and underground erosion velocity have been tested by self-made instruments. Results of tests and numerical simulation indicate that the pipelines not only change the original seepage field of a loess foundation, but also accelerate the underground erosion of a loess foundation. Loess on the top and upstream groundwater side of pipelines will be eroded first, finally causing the failure of foundation and the exposure of pipelines. The combination of soil solidified material and revegetation is suggested as an effective and durable solution to deal with the underground erosion problem of loess pipeline foundations.

To meet the requirements of OSGi distributed processing capabilities from enterprise computing, this paper proposes a convenient way which adds distributed computing capability to OSGi framework and supports interoperation between OSGi and legacy CORBA applications. This is achieved by using CORBA dynamic technology which implements the remote service invocation capability and CORBA naming service which supports remote service discovery capability. In the end, this paper proves the distributed processing capabilities by testing our implementation in a simple scenario with a legacy CORBA application.

MS is the most commonly used basal medium for the micropropagation of banana (Musa spp.), in which inorganic N source consists of NH4+-N and NO3--N, and NH4+:NO3- = 1:2. In the present study, basal medium for rooting culture was modified by supplying NO3--N as the sole N source at the concentration of 17.80 to 19.78 mmol·L-1. Not only was the percentage of qualified plantlets higher than that of MS or ½ MS, but the cost for medium preparation (per liter) was about $0.6 lower than that of MS based on local retail price, for the concentration of N decreased from about 60 mmol·L-1 to nearly 20 mmol·L-1. The effects of four factors: sucrose (25 to 35 g·L-1), NAA (0.2 to 1.0 mg·L-1), IBA (0.2 to 1.0 mg·L-1), and basal medium with modified N source on the percentage of qualified plantlets were studied by using orthogonal design. The variance analysis of data showed that all the four factors significantly affected the process of rooting culture. Among them, sucrose was the most important factor, followed by revised basal medium, IBA, and NAA. The optimal medium for rooting culture was BM II supplemented with 30 g·L-1 sucrose, 0.5 mg·L-1 NAA, and 0.5 mg·L-1 IBA. During the following acclimation phase, >90% of plantlets survived. Chemical name used: 6-benzylaminopurine (BA); indole-3-butyric acid (IBA); α-naphthaleneacetic acid (NAA).

With the rapid development of mobile health care, doctors have an urgent requirement to access to EMR (Electronic Medical Record) systems with iPad and other mobile tablets in wireless environment. But most existing EMR systems are based on Windows operating system, therefore how to provide mechanisms which can make EMR mobile becomes an important research issue in mobile healthcare field. This paper proposes an electronic medical review system named WSB-EMR based on web service. WSB-EMR, which aims at higher flexibility and cross-platform ability for different mobile tablet devices, uses service-oriented architecture and XML (Extensible Markup Language) technology to provide cross-platform access mode to EMR system, and can integrates HIS (Hospital Information System), EMR and LIS (Libratory Information System) systems seamlessly. Doctors can get access to patients' clinical diagnosis and treatment information at the bedside through wireless network with iPad or other tablets. Benefits are significant since the system was put into use.

To solve the problem of SVR (support vector regression) model selection, this paper proposed a SVM (support vector machine) model parameter optimization algorithm based on gradient descent algorithm. The algorithm obtained the local optimal model parameter by minimizing the model evaluation criteria over the parameter set. Then on the basis of Riemannian geometry, a conformal transformation suitable for SVR was proposed which corrected kernel function in a data-based way. This algorithm can further enhance the generalization ability of SVR. The simulated results are illustrated to show the feasibility and effectiveness of the algorithm. Keywords-support vector regression (SVR), model selection, gradient descent, Riemannian geometry