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排序方式: 共有227条查询结果,搜索用时 15 毫秒
1.
Rassoul Dinarvand Mohammed Massoud Alimorad Massoud Amanlou Hamid Akbari 《应用聚合物科学杂志》2006,101(4):2377-2383
Polyadipic anhydride (PAA), an aliphatic polyanhydride, and polytrimethylene carbonate (PTMC), an aliphatic polycarbonate, were synthesized via ring opening polymerization of oxepan‐2,7‐dione and melt‐condensation of trimethylene carbonate (1,3 dioxan‐2‐one), respectively. PTMC–PAA blend microspheres containing different ratios of buprenorphine HCl (2, 5, and 10%) were prepared by an oil‐in‐oil emulsion solvent removal method. Microspheres with different ratios of PTMC–PAA (85/15, 70/30, and 55/45) containing 5% buprenorphine HCl were prepared. Microspheres were spherical with visible cracks and pores on the surface. The average particle size of microspheres was around 200 μm for all microspheres. Drug loading efficiency of PTMC–PAA microspheres (85/15, 70/30, and 55/45) was 97.2, 95.2, and 70.2%, respectively. With the increase in the PTMC ratio, the melting point and the enthalpy of melting were both decreased. The mechanism for drug release from PTMC–PAA blend microspheres were generally a combination of drug diffusion through polymers and biodegradation of the polymers. In first three days, the release from microspheres followed zero order kinetics and was dependent on the PAA content. After three days the drug release from microspheres followed first order kinetics. In conclusion it was demonstrated that buprenorphine HCl release from microspheres could be successfully controlled by using different ratios of PTMC–PAA blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2377–2383, 2006 相似文献
2.
Factored Edge-Valued Binary Decision Diagrams form an extension to Edge-Valued Binary Decision Diagrams. By associating both an additive and a multiplicative weight with the edges, FEVBDDs can be used to represent a wider range of functions concisely. As a result, the computational complexity for certain operations can be significantly reduced compared to EVBDDs. Additionally, the introduction of multiplicative edge weights allows us to directly represent the so-called complement edges which are used in OBDDs, thus providing a one to one mapping of all OBDDs to FEVBDDs. Applications such as integer linear programming and logic verification that have been proposed for EVBDDs also benefit from the extension. We also present a complete matrix package based on FEVBDDs and apply the package to the problem of solving the Chapman-Kolmogorov equations. 相似文献
3.
For integrated spiral inductor synthesis, designers and design automation tools require efficient modeling techniques during
the initial design space exploration process. In this paper, we introduce an analytical frequency-dependent resistance model
for integrated spiral inductors. Based on our resistance formulation, we have developed a systematic technique for creating
wide-band circuit models for accurate time domain simulation. The analytical resistance model provides a fast alternative
to field solver-based approaches with typical errors of less than 2.6 percent while surpassing the accuracy of several other
analytical modeling techniques by an order of magnitude. Furthermore, the wide-band circuit generation technique captures
the frequency-dependent resistance of the inductor with typical errors of less than 3.2 percent. 相似文献
4.
Tamer Ragheb Arthur Nieuwoudt Yehia Massoud 《Analog Integrated Circuits and Signal Processing》2007,51(1):11-17
In this paper, we present an analytical modeling methodology for fully integrated inductively-degenerated CMOS narrow-band
cascode Low Noise Amplifiers (LNA) that captures short channel transistor effects to enable rapid design space exploration
in current and future process technologies. The modeling methodology captures the impact of parasitics on passive components,
ESD-protection structures, and devices to accurately predict both impedance matching and noise figure. Our modeling is suitable
for numerical optimization and fully automated synthesis for LNAs. The results indicate that the methodology models ESD-protected
LNA circuits with 47.9% better accuracy in noise figure when compared with several current analytical modeling techniques
with four orders of magnitude improvement in simulation time over circuit-level simulation. Given its speed and accuracy,
the analytical modeling methodology is well-suited for design space exploration. 相似文献
5.
In this paper, we develop accurate and scalable models for the magnetic inductance in bundles of single-walled carbon nanotubes, which have been proposed as a means to alleviate the increasingly critical resistance problems associated with traditional copper interconnect in very large scale integration (VLSI) applications. The models consider the density and statistical distribution of both metallic and semiconducting nanotubes within the bundle. We evaluate the speed, accuracy, and scalability of our magnetic inductance modeling techniques and previously proposed inductance models. The inductance model with the best performance evaluates the magnetic inductance of nanotube bundles with excellent accuracy when compared to modeling each nanotube individually and provides orders of magnitude improvement in CPU time as the bundle size increases. Leveraging the magnetic inductance modeling techniques, we determine the relative impact of magnetic and kinetic inductance. Based on our results, the relative value of magnetic and kinetic inductance on single-walled carbon nanotube (SWCNT) bundles is highly dependent on the bundle geometry and the per unit length kinetic inductance 相似文献
6.
R. Iris Bahar Dan Hammerstrom Justin Harlow William H. Joyner Jr. Clifford Lau Diana Marculescu Alex Orailoglu Massoud Pedram 《Computer》2007,40(1):25-33
Although nanoelectronics won't replace CMOS for some time, research is needed now to develop the architectures, methods, and tools to maximally leverage nanoscale devices and terascale capacity. Addressing the complementary architectural and system issues involved requires greater collaboration at all levels. The effective use of nanotechnology calls for total system solutions 相似文献
7.
Arthur Nieuwoudt Tamer Ragheb Yehia Massoud 《Analog Integrated Circuits and Signal Processing》2008,55(2):189-193
Given the increasing demand for integrated wireless systems in system-on-chip technology, narrow-band low noise amplifier (LNA) designs must be robust against variations in device parameters and passive component values to improve manufacturing yield for high volume applications. In this paper, we develop two design techniques for reducing the impact of component variations on narrow-band LNA performance. The results demonstrate that by increasing the bandwidth of the narrow-band LNA and applying more conservative design constraints, we can mitigate the reliability implications of process variations on impedance matching, gain, and power consumption. 相似文献
8.
Tolou Allahghadri Iraj Rasooli Parviz Owlia Mohammadreza Jalali Nadooshan Tooba Ghazanfari Massoud Taghizadeh Shakiba Darvish Alipoor Astaneh 《Journal of food science》2010,75(2):H54-H61
ABSTRACT: Cumin (Cuminum cyminum) is one of the commonly used spices in food preparations. It is also used in traditional medicine as a stimulant, a carminative, and an astringent. In this study, we characterized the antimicrobial, antioxidant, and cytotoxic activities of cumin. E. coli, S. aureus, and S. faecalis were sensitive to various oil dilutions. The total phenol content of the essential oil was estimated to be 33.43 μg GAE/mg of the oil. The oil showed higher antioxidant activity compared with that of BHT and BHA. The cumin essential oil exhibited a dose-dependent scavenging of DPPH radicals and 5.4 μg of the oil was sufficient to scavenge 50% of DPPH radicals/mL. At a concentration of 0.1 μL/mL, oil destructed Hela cells by 79%. The antioxidant activity of cumin essential oil might contribute to its cytotoxic activity. Acute and subchronic toxicity was studied in a 30-d oral toxicity study by administration to Wistar rats of the essential oil. A 17.38% decrease in WBCs count, and 25.77%, 14.24%, and 108.81% increase in hemoglobin concentration, hematocrit, and platelet count, respectively, were noted. LDL/HDL ratio was reduced to half, which adds to the nutritional effects of cumin. Thus, cumin with a high phenolic content and good antioxidant activity can be supplemented for both nutritional purposes and preservation of foods. 相似文献
9.
Although parking revenue is a principal source of income, supply of parking infrastructure at airports is based largely on expected needs. Although that is a rational basis, high investment costs and management fees are requiring developers and financiers to carefully analyze investment risks. This paper focuses on sources of investment risk in airport parking infrastructure development and discusses the application of Monte Carlo simulation to estimate and understand the impacts of cash flow uncertainties on project feasibility. It is shown that cost overruns, which are common in construction project development, have the most significant impact on return risk. 相似文献
10.
Hassanpour Jafar Lotfipoor Ashkan Morsali Massoud 《Bulletin of Engineering Geology and the Environment》2021,80(7):5725-5742
Bulletin of Engineering Geology and the Environment - Water inflow caused by tunneling can have severe impacts on the springs’ discharge rate. If these impacts have not been predicted... 相似文献