scholarly journals Critical parameters for design and development of multivalent nanoconstructs: recent trends

Author(s):  
Avijit Kumar Bakshi ◽  
Tanweer Haider ◽  
Rahul Tiwari ◽  
Vandana Soni
Author(s):  
Simone Berti ◽  
Pietro Fracassi ◽  
Alessandra Mattioli ◽  
Varuna Reddy Potula ◽  
Cristiano Lotti

Rotary screw type positive displacement (RSPD) pumps are commonly used in Oil and Gas Industry for pumping of mineral lube oil in services where they can be mechanically driven by gears coupled to a train driver. Installation of these pumps is critical and should be designed jointly by vendors and users according to project specific restrictions (i.e. the arrangement of the entire oil circulation system). This paper describes a real case in which restrictions due to lube oil system arrangement have produced low pump suction head and have amplified the influence of air bubbles that remained entrained in oil despite lube oil tank degassing. The investigations have been directed toward the mathematical modeling of the aeration phenomenon coupled with experimental measurements of critical parameters taken on the shop plant. Among corrective actions identified and considered there are reduction of quantity of air entering the lube oil system and revamping of the entire lube oil system with changes in piping, tank and also in pump model together with special modifications of internal path to enhance air handling capabilities. In order to validate pump behavior with reference to resistance to aeration (monitoring noise and vibration) a special simulation set-up was jointly developed by end user and manufacturer on a pilot test bench to carry out the various performance tests. The numerical data collected during shop aeration test have confirmed that the pump was able to handle the expected amount of entrained air with noise and vibrations within industrial limits. The pumps tested in the pilot bench were installed at user’s site and the effectiveness of the synergic corrective actions listed above was successfully verified. The study concludes that an early estimation of entrained air in the lube oil system is critical for design and development of either the RSPD pump or the entire lube oil circuit of a motor compressor train. When a critical quantity of entrained air is likely to be reached at pump suction (near 10% in volume), pump manufacturers and end users should apply some basic rules related to “design for aeration” of the pump and agree on a non-routine test to be performed at manufacturer’s shop before pump installation at site. This will serve as a reliable prediction of pump air handling capabilities, without which effective operation, reliability and durability of the pump could be jeopardized.


Author(s):  
Simone Berti ◽  
Pietro Fracassi ◽  
Alessandra Mattioli ◽  
Varuna Reddy Potula ◽  
Cristiano Lotti

Rotary screw type positive displacement (RSPD) pumps are commonly used in oil and gas industry for pumping of mineral lube oil in services where they can be mechanically driven by gears coupled to a train driver. Installation of these pumps is critical and should be designed jointly by vendors and users according to project specific restrictions (i.e., the arrangement of the entire oil circulation system). This paper describes a real case in which restrictions due to lube oil system arrangement have produced low pump suction head and have amplified the influence of air bubbles that remained entrained in oil despite lube oil tank degassing. The investigations have been directed toward the mathematical modeling of the aeration phenomenon coupled with experimental measurements of critical parameters taken on the shop plant. Among corrective actions identified and considered there are reduction of quantity of air entering the lube oil system and revamping of the entire lube oil system with changes in piping, tank and also in pump model together with special modifications of internal path to enhance air handling capabilities. In order to validate pump behavior with reference to resistance to aeration (monitoring noise and vibration) a special simulation setup was jointly developed by end user and manufacturer on a pilot test bench to carry out the various performance tests. The numerical data collected during shop aeration test have confirmed that the pump was able to handle the expected amount of entrained air with noise and vibrations within industrial limits. The pumps tested in the pilot bench were installed at user's site and the effectiveness of the synergic corrective actions listed above was successfully verified. The study concludes that an early estimation of entrained air in the lube oil system is critical for design and development of either the RSPD pump or the entire lube oil circuit of a motor compressor train. When a critical quantity of entrained air is likely to be reached at pump suction (near 10% in volume), pump manufacturers and end users should apply some basic rules related to “design for aeration” of the pump and agree on a nonroutine test to be performed at manufacturer's shop before pump installation at site. This will serve as a reliable prediction of pump air handling capabilities, without which effective operation, reliability and durability of the pump could be jeopardized.


Author(s):  
D. J. Folenta ◽  
J. Motzer ◽  
F. X. Critelli

This paper presents the rationale for the design and development of high horsepower marine planetary gears along with the results of some engineering studies and a progress report covering the development testing of full-scale 40,000- and 60,000-shp marine planetary transmission modules. Recent trends in ship construction, modularization, and introduction of new marine prime movers has given the impetus to the design and development of a family of modular form marine planetary reduction gears. Work completed to date including detail gear designs, transmission hardware trade-off studies, marine architectural installation studies, actual hardware manufacturing and testing, as well as information published in the literature on the use of and the performance of marine planetary gears, shows that the concept of high horsepower marine planetary gears is viable and that substantial benefits will accrue to the owner and the user of this type of equipment. Work described herein related to a joint Curtiss-Wright Power Subsystems/Maritime Administration project on planetary Marine Transmission System Development (Contract Nos. 1-35536 and 3-36247).


2018 ◽  
Vol 24 (21) ◽  
pp. 2394-2402 ◽  
Author(s):  
Leming Sun ◽  
Yanzi Hu ◽  
Lianbing Zhang

Background: As the quick development of modern methods and technologies currently, more and more drugs have been invented with a better efficiency. However, the poor water solubility has limited the drugs’ pharmaceutical application. Methods: Tremendous research has been put in the design and development of nanocrystals for pharmaceutical applications over the past few decades. The nanocrystals not only have the chance to solve the poor solubility problem, but also could conquer the bioavailability and even the specific delivery problems. The physical properties of drugs can be changed dramatically due to the change of their size in a nanodimension. Therefore, the nanocrystals have great potential to overcome the challenge to design and development of new drugs for pharmaceutical applications. Results: In this review, we provide an overview of the recent trends in nanocrystals for pharmaceutical applications. Conclusion: The current technologies including top-down, bottom-up, and combinative technologies for nanocrystals were fully examined. Most importantly, the emphasis is put on the pharmaceutical applications including their formulation, administration methods, safety, and toxicity. The commercial status, limitations, challenges, and future trends of the nanocrystals for pharmaceutical applications were also discussed.


2021 ◽  
Author(s):  
Selvakani Prabakaran ◽  
Rajan Mariappan

Recent trends in biomedical research have been focused on the design and development of biomaterials with multi-functional properties. These biomaterials with multi-functional properties offer a successful path to regenerate soft...


Author(s):  
Pallavi Dharwada ◽  
Joel S. Greenstein ◽  
Anand K. Gramopadhye ◽  
Steve J. Davis

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