Factors Affecting Rearing of Settled Zebra Mussels in a Controlled Flow-Through System

1998 ◽  
Vol 60 (3) ◽  
pp. 231-235 ◽  
Author(s):  
Y. Zhang ◽  
S. E. Stevens ◽  
T-Y. Wong
Keyword(s):  
Zebra Mussels ◽  
Factors Affecting ◽  
Flow Through ◽  
Controlled Flow

Pickering B Nuclear Power Generating Station Condenser Performance Improvement

2003 ◽  
Author(s):  
Wayne Allen ◽  
David Anderson ◽  
Bert Mayer
Keyword(s):  
Dreissena Polymorpha ◽  
Nuclear Power ◽  
Cooling Water ◽  
Zebra Mussels ◽  
Condenser Tube ◽  
Turbine Generator ◽  
Cleaning System ◽  
Generation Capacity ◽  
Flow Through ◽  
Electric Generation

The Ontario Power Generation (OPG) Pickering B Facility consists of four 540 MW nuclear generating units. Each unit is furnished with a once-through Condenser Cooling Water (CCW) System that uses Lake Ontario water. Zebra mussels (Dreissena polymorpha) are infesting the condenser cooling water intakes at Pickering. The mature mussels and their shells become entrained in the CCW, are deposited in the condenser inlet water boxes, and become lodged in the condenser tube sheets and within the tubes. As a result, the flow through the condenser is reduced, and the existing Condenser Tube Cleaning System (CTCS) performance is degraded. This reduces the Turbine-Generator generating capability that results in a loss of electric generation revenues for OPG, and increased maintenance costs to manually remove the zebra mussels from the condenser. OPG decided to install Debris Filters in the six 72-inch diameter inlets of each of the four Pickering B units to automatically remove the zebra mussels before they enter the condensers and discharge them back into the lake. The Debris Filters for Unit 8 were installed during a scheduled outage in the winter of 2001/2002. The Unit 5 installation was completed at the end of 2002 and the Unit 6 & 7 installations are scheduled for 2003. The installed equipment is performing as expected. The zebra mussels are intercepted by the Debris Filter, and are automatically discharged into the condenser bypass and returned to the lake. The CTCS system can again perform its intended function to prevent bio-fouling buildup inside the condenser tubes. As a result, generation capacity increased and maintenance expenditures decreased with a net result of increased revenues for OPG.

scholarly journals Generation of multilayered structures for biomedical applications using a novel tri-needle coaxial device and electrohydrodynamic flow

2008 ◽  
Vol 5 (27) ◽  
pp. 1255-1261 ◽  
Author(s):  
Z Ahmad ◽  
H.B Zhang ◽  
U Farook ◽  
M Edirisinghe ◽  
E Stride ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Controlled Release ◽  
Biomedical Engineering ◽  
Biomedical Applications ◽  
Short Communication ◽  
Multilayered Structures ◽  
Electrohydrodynamic Flow ◽  
Novel Device ◽  
Flow Through ◽  
Controlled Flow

In this short communication, we describe the scope and flexibility of using a novel device containing three coaxially arranged needles to form a variety of novel morphologies. Different combinations of materials are subjected to controlled flow through the device under the influence of an applied electric field. The resulting electrohydrodynamic flow allows us to prepare double-layered bubbles, porous encapsulated threads and nanocapsules containing three layers. The ability to process such multilayered structures is very significant for biomedical engineering applications, for example, generating capsules for drug delivery, which can provide multistage controlled release.

scholarly journals EXPERIMENTAL INVESTIGATION INTO FACTORS AFFECTING THE TRANSIENT FLOW OF FLUID THROUGH AN ORIFICE IN REALISTIC CONDITIONS

2021 ◽  
Vol 158 (A3) ◽  
Author(s):  
C D Wood ◽  
D A Hudson ◽  
M Tan ◽  
A J Sobey ◽  
Y Wang
Keyword(s):  
Transient Flow ◽  
Internal Flow ◽  
Environmental Safety ◽  
Empirical Measure ◽  
Factors Affecting ◽  
Hull Girder ◽  
Flooding Event ◽  
Simplified Method ◽  
Flow Through ◽  
Coefficient Of Discharge

During operations, damage can occur with a resulting ingress or egress of fluid. The incoming water affects the reserve buoyancy and it can also change stability and hull girder loading. During a flooding event it is vital that the flow through the damaged orifice and the movement of floodwater around the structure can be predicted quickly to avoid further damage and ensure environmental safety. The empirical measure coefficient of discharge is used as a simplified method to quantify the flooding rate. In many internal flow applications the coefficient of discharge is estimated to be 0.6 but recent research shows that it can vary considerably when applied to transient flooding flows. This paper uses an experimental setup to investigate how changes to the orifice edges and position within the structure affect the flow. It is then used to investigate the coefficient in a more realistic scenario, a static compartment in waves.

Storage Characteristics of Fresh Swordfish Steaks Stored in Carbon Dioxide-Enriched Controlled (Flow-Through) Atmospheres

1983 ◽  
Vol 46 (5) ◽  
pp. 434-440 ◽  
Author(s):  
V. OBERLENDER ◽  
M. O. HANNA ◽  
R. MIGET ◽  
C. VANDERZANT ◽  
G. FINNE
Keyword(s):  
Carbon Dioxide ◽  
Major Part ◽  
Controlled Atmosphere ◽  
Packaging System ◽  
Brochothrix Thermosphacta ◽  
Flow Through ◽  
Gaseous Atmospheres ◽  
Controlled Flow ◽  
Storage Characteristics ◽  
Lactobacillus Spp

A flow-through controlled atmosphere packaging system using a number of different carbon dioxide-enriched gaseous compositions was demonstrated to be effective in retarding the growth of microorganisms on fresh swordfish steaks held at 2°C for 22 d. During the first 14 d of storage, Pseudomonas spp. either dominated or represented a major part of the microflora of steaks in all gaseous atmospheres tested. However, in atmospheres containing 70% CO2 or in pure CO2, heterofermentative Lactobacillus spp. and Brochothrix thermosphacta were a major part of the microflora, particularly after the 14th day of storage. Both total volatile nitrogen and trimethylamine, often used as quality indicators for fresh seafoods, increased more slowly for swordfish steaks stored in CO2-enriched atmospheres than steaks stored in air. Advantages of using a controlled atmosphere flow-through system for storage of fresh seafoods include: (a) a stable gas composition, (b) individual portions can be removed from a master package without losing or disrupting the gaseous atmosphere, and (c) volatile off-odors which accumulate during storage in sealed CO2-enriched atmospheres are carried off with the flow-through gas.

Analysis of factors affecting gas exchange in intravascular blood gas exchanger

1994 ◽  
Vol 77 (4) ◽  
pp. 1716-1730 ◽  
Author(s):  
S. C. Niranjan ◽  
J. W. Clark ◽  
K. Y. San ◽  
J. B. Zwischenberger ◽  
A. Bidani
Keyword(s):  
Gas Exchange ◽  
Hollow Fiber ◽  
Gas Flow ◽  
Coaxial Cylinder ◽  
Co2 Removal ◽  
Transfer Resistance ◽  
Factors Affecting ◽  
Unit Structure ◽  
Alternating Direction ◽  
Flow Through

A mathematical model of an intravascular hollow-fiber gas-exchange device, called IVOX, has been developed using a Krogh cylinder-like approach with a repeating unit structure comprised of a single fiber with gas flowing through its lumen surrounded by a coaxial cylinder of blood flowing in the opposite direction. Species mass balances on O2 and CO2 result in a nonlinear coupled set of convective-diffusion parabolic partial differential equations that are solved numerically using an alternating-direction implicit finite-difference method. Computed results indicated the presence of a large resistance to gas transport on the external (blood) side of the hollow-fiber exchanger. Increasing gas flow through the device favored CO2 removal from but not O2 addition to blood. Increasing blood flow over the device favored both CO2 removal as well as O2 addition. The rate of CO2 removal increased linearly with the transmural PCO2 gradient imposed across the device. The effect of fiber crimping on blood phase mass transfer resistance was evaluated indirectly by varying species blood diffusivity. Computed results indicated that CO2 excretion by IVOX can be significantly enhanced with improved bulk mixing of vena caval blood around the IVOX fibers.

scholarly journals Air Distributor Designs for Fluidized Bed Combustors: A Review

2016 ◽  
Vol 6 (3) ◽  
pp. 1029-1034 ◽  
Author(s):  
A. Shukrie ◽  
S. Anuar ◽  
A. N. Oumer
Keyword(s):  
Pressure Drop ◽  
Fluidized Bed ◽  
Air Flow ◽  
Fluidized Bed Combustion ◽  
Key Factors ◽  
Successful Operation ◽  
Factors Affecting ◽  
Plate Design ◽  
Flow Through ◽  
Critical Overview

Fluidized bed combustion (FBC) has been recognized as one of the suitable technologies for converting a wide variety of biomass fuels into energy. One of the key factors affecting the successful operation of fluidized bed combustion is its distributor plate design. Therefore, the main purpose of this article is to provide a critical overview of the published studies that are relevant to the characteristics of different fluidized bed air distributor designs. The review of available works display that the type of distributor design significantly affects the operation of the fluidized bed i.e., performance characteristics, fluidization quality, air flow dynamics, solid pattern and mixing caused by the direction of air flow through the distributors. Overall it is observed that high pressure drop across the distributor is one of the major draw backs of the current distributor designs. However, fluidization was stable in a fluidized bed operated at a low perforation ratio distributor due to the pressure drop across the distributor, adequate to provide uniform gas distribution. The swirling motion produced by the inclined injection of gas promotes lateral dispersion and significantly improves fluidization quality. Lastly, the research gaps are highlighted for future improvement consideration on the development of efficient distributor designs.

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