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21.
Shunting systems widely used for the treatment of hydrocephalus have been connected with certain risks and potential complications which stem from implanting a non-biological material into the human body. Several complications have been reported to arise from the insertion of ventriculo-peritoneal shunts. This short report highlights the observation that when anaerobic meningitis together with gram negative E. Coli in the CSF of a V-P shunted patient is found, bowel perforation should be assumed. Four cases developed such a complication among 643 hydrocephalic patients of various etiology over a period of ten years.  相似文献   
22.
Neural Computing and Applications - In order to provide benchmark performance for Urdu text document classification, the contribution of this paper is manifold. First, it provides a publicly...  相似文献   
23.
Significant growth of multimedia content on the World Wide Web (or simply ??Web??) has made it an essential part of peoples lives. The web provides enormous amount of information, however, it is very important for the users to be able to gauge the trustworthiness of web information. Users normally access content from the first few links provided to them by search engines such as Google or Yahoo!. This is assuming that these search engines provide factual information, which may be popular due to criteria such as page rank but may not always be trustworthy from the factual aspects. This paper presents a mechanism to determine trust of websites based on the semantic similarity of their multimedia content with already established and trusted websites. The proposed method allows for dynamic computation of the trust level of websites of different domains and hence overcomes the dependency on traditional user feedback methods for determining trust. In fact, our method attempts to emulate the evolving process of trust that takes place in a user??s mind. The experimental results have been provided to demonstrate the utility and practicality of the proposed method.  相似文献   
24.
This study aims to examine the morphology and mechanical properties (tensile, flexural, and compressive) of epoxy composites reinforced with epoxy date palm leaves (EDPL), epoxy date palm branch (EDPB), and epoxy/hardener date palm core shell (EDPC) fibers (particle size <1 μm depend on the date palm fibers). A three-step technique was used to obtain the composites. The EDPL composites showed a maximum tensile strength of 3.45 MPa, while the EDPB composites showed maximum compressive and flexural rigidity of 9.46 and 5.55 MPa, respectively, owing to the good compatibility of fiber-matrix bonding. In this work, epoxy composites reinforced with date palm fibers (DPF) leaves, branches, and core shell were recycled using a cost-effective and easily reproducible three-step technique. EDPC fibers fabricated with 64.65% weight carbon fibers content demonstrated improved tensile strengths and stiffness properties. The three samples of palm date composites revealed mechanical properties that could be used to trial these fibers for manufacturing purposes, and to exploit their extraordinary mechanical properties shown in current results.  相似文献   
25.
To impart easy‐care properties to cellulose‐containing fabrics along with avoiding any harmful effects of formaldehyde on both the health and the environment, attempts have been made to use citric acid (CA) as an ester crosslinking agent along with different catalytic systems in the absence and presence of certain additives. Further, fixation conditions, type of crosslinking agent, as well as type of substrate have been studied. Results revealed that the enhancement in carboxyl content, performance properties, and the decrease in tear strength (TS) as well as in whiteness indices (WI) of the finished fabric samples were increased by increasing CA concentration up to 80 g/L and by raising thermofixation temperature from 140 up to 180°C for 90 s. Inclusion of triethanolamine hydrochloride (TEA. HCl), decreased the carboxyl content, TS, color strength K/S, as well as oily stain release rating (SRR) of the finished fabric samples along with an increase in bound nitrogen (%N), wrinkle recovery angle WRA, and an improvement in WI without affecting the durable press rating (DP). Within the range examined (0–30 g/L), increasing PEG‐600 concentration improved the wet resiliency, TS, as well as WI properties of the finished samples. Increasing DMDHEU ratio in the CA/DMDHEU crosslinking system gave rise to an increase in %N, WRA (dry and wet), DP, as well as in free CH2O of finished fabrics, along with a slight improvement in WI values. On the other hand, the TS, carboxyl content, K/S, SRR values of the finished fabric samples were lower at a higher DMDHEU ratio. Increase in carboxyl content, %N, WRA (dry and wet), DP and SRR, as well as extent of post dyeing (K/S) of the treated fabric samples upon using different ester crosslinking agents followed the descending order: citric acid > pyromellitic dianhydride. The opposite holds true for the TS, and WI values. Among the esterifying catalysts used, and for a given set of finishing conditions, NaH2PO2 · H2O proved to be the most effective one, and the following order of effectiveness may be drawn: NaH2PO2 · H2O > K2HPO4 > Na3–citrate > Na2–tartrate. Inclusion of silicone softener in the finishing formulation brought about an improvement in softeness degree, WRA, %N, DP, TS as well as K/S values along with a decrease in carboxyl content, SRR, and WI values of the treated fabric samples, regardless of the used silicone softener.The performance properties of the finished fabric samples were determined by the type and nature of the substrate. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2243–2253, 2002  相似文献   
26.
The behaviour of reactive dyes of high reactivity during the printing process of 100% cotton fabrics from an alkaline and acidic printing paste was studied in detail. The printing pastes were stored for different periods of time and then the fabrics were printed. The samples were subjected to two methods of fixation, the first by steaming and the second by thermofixation. The effects of different factors such as alkali and acid concentration, storage time of the printing pastes and method of fixation on the K/S values of the prints were investigated. The fastness properties of the printed areas were also measured to determine the improvement obtained by acidic printing with high-reactivity reactive dyes on cotton fabrics.  相似文献   
27.
For the last four decades Unmanned Air Vehicles (UAVs) have been extensively used for military operations that include tracking, surveillance, active engagement with weapons and airborne data acquisition. UAVs are also in demand commercially due to their advantages in comparison to manned vehicles. These advantages include lower manufacturing and operating costs, flexibility in configuration depending on customer request and not risking the pilot on demanding missions. Even though civilian UAVs currently constitute 3 % of the UAV market, it is estimated that their numbers will reach up to 10 % of the UAV market within the next 5 years. Most of the civilian UAV applications require UAVs that are capable of doing a wide range of different and complementary operations within a composite mission. These operations include taking off and landing from limited runway space, while traversing the operation region in considerable cruise speed for mobile tracking applications. This is in addition to being able traverse in low cruise speeds or being able to hover for stationary measurement and tracking. All of these complementary and but different operational capabilities point to a hybrid unmanned vehicle concept, namely the Vertical Take-Off and Landing (VTOL) UAVs. In addition, the desired UAV system needs to be cost-efficient while providing easy payload conversion for different civilian applications. In this paper, we review the preliminary design process of such a capable civilian UAV system, namely the TURAC VTOL UAV. TURAC UAV is aimed to have both vertical take-off and landing and Conventional Take-off and Landing (CTOL) capability. TURAC interchangeable payload pod and detachable wing (with potential different size variants) provides capability to perform different mission types, including long endurance and high cruise speed operations. In addition, the TURAC concept is to have two different variants. The TURAC A variant is an eco-friendly and low-noise fully electrical platform which includes 2 tilt electric motors in the front, and a fixed electric motor and ducted fan in the rear, where as the TURAC B variant is envisioned to use high energy density fuel cells for extended hovering time. In this paper, we provide the TURAC UAV’s iterative design and trade-off studies which also include detailed aerodynamic and structural configuration analysis. For the aerodynamic analysis, an in-house software including graphical user interface has been developed to calculate the aerodynamic forces and moments by using the Vortex Lattice Method (VLM). Computational Fluid Dynamics (CFD) studies are performed to determine the aerodynamic effects for various configurations For structural analysis, a Finite Element Model (FEM) of the TURAC has been prepared and its modal analysis is carried out. Maximum displacements and maximal principal stresses are calculated and used for streamlining a weight efficient fuselage design. Prototypes have been built to show success of the design at both hover and forward flight regime. In this paper, we also provide the flight management and autopilot architecture of the TURAC. The testing of the controller performance has been initiated with the prototype of TURAC. Current work focuses on the building of the full fight test prototype of the TURAC UAV and aerodynamic modeling of the transition flight.  相似文献   
28.
In this paper, we investigated an approach for robots to learn to adapt dance actions to human’s preferences through interaction and feedback. Human’s preferences were extracted by analysing the common action patterns with positive or negative feedback from the human during robot dancing. By using a buffering technique to store the dance actions before a feedback, each individual’s preferences can be extracted even when a reward is received late. The extracted preferred dance actions from different people were then combined to generate improved dance sequences, i.e. performing more of what was preferred and less of that was not preferred. Together with Softmax action-selection method, the Sarsa reinforcement learning algorithm was used as the underlining learning algorithm and to effectively control the trade-off between exploitation of the learnt dance skills and exploration of new dance actions. The results showed that the robot learnt, using interactive reinforcement learning, the preferences of human partners, and the dance improved with the extracted preferences from more human partners.  相似文献   
29.
Electrically and thermally conductive resins can be produced by adding conductive fillers to insulating polymers. Mechanical properties, such as tensile modulus, are also important. This research focused on performing compounding runs followed by injection molding and tensile testing of carbon‐filled nylon 6,6 and polycarbonate‐based resins. The three carbon fillers investigated included an electrically conductive carbon black, synthetic graphite particles, and a milled pitch–based carbon fiber. For each polymer, resins were produced and tested that contained varying amounts of these single‐carbon fillers. In addition, combinations of fillers were investigated by conducting a full 23 factorial design and a complete replicate in each polymer. These tensile modulus experimental results were then compared to results predicted by several different models. For the composites containing only one filler type, the Nielsen model with the modified Ψ term provided the best prediction of the actual experimental values. For the composites containing more than one filler type, a new parameter, which includes the vibrated bulk density (VBD) of the fillers, was incorporated into the Nielsen model with the modified Ψ term. This model with the new VBD parameter provided the best estimate of experimental tensile modulus for composites containing multiple‐filler types. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1716–1728, 2003  相似文献   
30.
Squash, like other Cucurbitaceae, have unique sterol profiles that offer an excellent opportunity to examine the relationship between sterol biosynthesis and plant growth. To determine the effect of sterol biosynthesis inhibition on squash growth, Cucurbita maxima seedlings with and without cotyledons were subjected to increasing concentrations of the cycloartenol synthase (EC 5.4.99.8) inhibitor 3β-(2-diethylaminoethoxy) androstenone (U18666A). Inhibition of shoot growth was concentration-dependent (from 0, 2, 5, 10, and 20 μM); plants with intact cotyledons grew to 26.4, 23.7, 21.6, 20.0, and 15.6 cm, respectively, at the above inhibitor concentrations, compared to 25.5, 19.4, 17.0, 12.0, and 11 cm for plants with severed cotyledons. In plants with severed cotyledons, 10 and 20 μM U18666A caused rapid necrosis of the first two, newly emerged, primary leaves, and halted new leaf formation. Secondary root formation was initially affected at all inhibitor concentrations regardless of whether cotyledons were present or not. Vegetative tissue showed a decrease in the accumulation of the major squash sterol, 7, 22-stigmastadienol, accompanied by increased accumulation of minor sterol components. Sterol profiles in cotyledons were unaltered. The data show that sterols are crucial for maintaining plant growth and viability, but do not address the cotyledonary effect on growth with respect to sterol biosynthesis. Based on a paper presented at the Symposium on the “Regulation of Biosynthesis and Function of Isopentenoids”, Atlanta, Georgia, May 1994.  相似文献   
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