Journal of Science and Technique
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STUDY ON THE SCALEABLE SYNTHESIS OF SORAFENIB TOSYLATE FOR TREATMENT OF CANCER
Get PDFSorafenib tosylate, band name Nexavar, is an effective multi-targeted kinase which have broad spectrum of antitumor activity such as inhibitor renal cell carcinoma, hepatocellular cancer and advance thyroid tumor. The objective of this paper is to study synthesis of sorafenib tosylate in large scale up to 220 gram. In this process, all intermediates, as well as final product, were recrystallized as purification method without chromatography, and it ample useful to reduce cost of commercial treatment cancer drug
PHASE ESTIMATION AND COMPENSATION UNDER DIFFERENT NONLINEARITIES INCURRED BY HIGH POWER AMPLIFIERS IN MIMO-STBC SYSTEMS
Get PDFUpdated nonlinearity models for solid-state power amplifiers (SSPAs) include both amplitude and phase distortions, and thus being the same as nonlinearities in traveling-wave tube amplifiers (TWTAs), result in detrimental effects for multiple-input multiple-output space-time block code (MIMO-STBC) systems with nonlinear amplifications. This work presents a thorough investigation for the performance of a non-parametric phase estimation and compensation method for receive signal in such systems with different nonlinearities incurred from typical types of HPAs. Numerical simulations verify the relevance of theoretical arguments
INVESTIGATING INFLUENCE OF STIFFNESS ON VIBRATION OF ELEVATING AND TRAVERSING MECHANISMS OF 37 mm TWIN ANTI-AIRCRAFT GUN TYPE 65
Get PDFIn terms of chasing and tracking high speed targets, elevating and traversing mechanisms play an important role. This paper presents a method for calculating stiffness and vibrationof those mechanisms of those mechanisms. The method used in this paper is based on machine dynamic theory which is matched with designing materials. The result is used to determine the stiffness values of elevating and traversing mechanisms and the vibration laws of those mechanisms, which is further applied to research on the stability of firing guns
PERFORMANCE ANALYSIS OF REPEATED INDEX MODULATION FOR OFDM WITH MRC DIVERSITY OVER NAKAGAMI-m FADING CHANNEL
Get PDFThis paper investigates the symbol error performance of Repeated Index Modulation for Orthogonal Frequency Division Multiplexing with Maximal Ratio Combining diversity (ReIM-MRC) over Nakagami-m fading channel. Using the repeated transmission at the transmitter and MRC combiner at the receiver allows ReIM-MRC to achieve the diversity gain in both space and frequency domains. The system performance over Nakagami-m fading channel is also successfully analyzed. The tightness of simulation and theoretical results proves that our proposed scheme can attain considerably better performance than the benchmarks at the same spectral efficiency
MAPPING REEF ZONATIONS OF THE ATOLLS IN TRUONG SA ISLANDS BY USING LANDSAT 8OLI IMAGERY
Get PDFThe Truong Sa islands play an essential part in military, security and defense, and socio-economic purposes. Truong Sa consists of many islands and atolls. However, the reef zonations or geomorphic zones of coral reefs of the atolls are poorly documented because of the absence of field measurement data, especially in disputed areas. The authors use Landsat 8OLI satellite imagery and the Support vector machine (SVM) classification method to classify the atolls' reef zonation in the paper. The authors also experienced the DII index for bands 2, 3, 4 of the Landsat 8OLI image to correct the water column in the pre-processing image step, which are the input data of the classification processing. The classification accuracy achieved 97.8% and 98.3%. The study area is at Toc Tan island and Thuyen Chai island
RESEARCH AND CALCULATION OF METHOD TO ASSEMBLE SMALL PLASTIC FLOATING PONTOONS MAKING FLOATING WORKING FLOOR DURING UNDERWATER DRILLING
Get PDFThe present article proposes the calculation of a floating working platform assembled from small plastic floating pontoons used in drilling underwater borehole. The author uses self-programmed software by the Visual Basic language to check the buoyancy, the stability of the platform. Result of the survey shows optimal option of floating working platform to apply in practice. The author draws conclusions for the selected option of platform to build a scientific basis to determine the possibility of using plastic floating pontoon to make floating platforms used for the drilling underwater borehole
Influence of masonry on infilled frame with and without opening
Get PDFThe effect of masonry infills on the global response of frames is widely recognized but it is often neglected in the analytical models. Because of lack of effectively technique for modelling the infilled frame, in current practice, the structure is normally designed as a pure frame and masonry is considered as static load. Researches show that an infilled frame structure without opening actually performs better than a bare frame one against statistic or dynamic forces but when masonry infills have opening, however, the analytical model is again difficult. In this study, masonry infills are considered a building envelope with load-bearing function. A finite element procedure for the effective properties of microcracked viscoelastic masonry based on homogenization technique is provided to take into account the influence of crack density and time. It is also recommended as a simple means of modeling the behavior of the masonry infilled frame with and without opening. The results showed that under statistic loads, the masonry infills even in case with opening much reduce the displacement of frame compared with bare frame and the masonry significantly influences the principal stress field upheaval in the frame. This suggests that it is necessary to take into account the behavior of micro-cracked viscoelastic masonry to evaluate more accurately the global response of frames and the masonry infills with and without opening
An experimental study on the relationship between energy factor and percentage of oversize rock on electric explosion model
Get PDFThis article has chosen and carried out a study to examine the theoretical and experimental basis of the influence of energy factor, and the number of free face in the tunnel on the proportion of oversized rock after explosion by the explosive charge in the borehole, established an empirical relationship between the percentage of oversized rocks and the energy factor under different number of free face, in order to study the completion of the tunnel rock breaking
APPLICATION OF FAA METHOD FOR EVALUATING THE IMPACT OF AIRFIELD PAVEMENT ROUGHNESS ON AIRCRAFT WHEEL DYNAMIC LOADING
Get PDFThe paper presents the researched content to apply BBI (Boeing Bump Index) method of ICAO, FAA to evaluate the influence of airfield pavement roughness on the dynamic load of aircraft wheel with measured data in Cam Ranh International Airport, thereby proposing to apply to the actual design and operation of the airports in Vietnam
STUDY ON SOME DURABILITY PROPERTIES OF HIGH-STRENGTH FINE-GRAINED CONCRETE USING SALINE SAND AND CRUSHED AGGREGATE
Get PDFThis paper presents the results of research on some durability properties of high-strength fine-grained concrete made from saline sand and crushed aggregates with different mixing ratios. The specific mechanical properties and durability of concrete when working in a saline environment were tested, including compressive strength, water absorption, sulfate durability, and the alkali-aggregate reaction of concrete. The results show that: when replacing regular aggregate in C50 concrete with a mixture of salted sand and crushed aggregate with an appropriate mixing ratio, the concrete has a compressive strength of over 50 MPa, and water absorption reduces significantly. The sulfate and alkali-aggregate reaction are guaranteed to meet the requirements set forth by the standards for sulfate and alkali-resistant durability concrete. This result has great significance in the study and application of high-strength fine-grained concrete made from saline sand to build the constructions in marine and island environments