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2008

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Articles 3061 - 3090 of 4190

Full-Text Articles in Engineering

Synthesis And Characterisation Of Raman Nanotags For Molecular Detection, James Otieno Nyagilo Jan 2008

Synthesis And Characterisation Of Raman Nanotags For Molecular Detection, James Otieno Nyagilo

Bioengineering Theses - Archive

The realization that most diseases are preceded or accompanied by changes in the genetic and cellular level of an organism has increased with the need for imaging modalities, with the sensitivity and specificity, to quantitatively detect biomolecules at those levels. Specifically there has been a need for the development of a modality that has the ability to detect multiple biomolecules from a single sample in order to increase accuracy of molecular diagnosis and allow for early detection of terminal diseases. Surface enhanced Raman spectroscopy provides potential for such a modality. The distinct spectrum of each Raman active molecule serves as …


Visible To Near Infra Red Hyperspectral Imaging: Visualizing The Neurological And Biological Nature Of Ischemic Tissue, Swetha Suresh Jan 2008

Visible To Near Infra Red Hyperspectral Imaging: Visualizing The Neurological And Biological Nature Of Ischemic Tissue, Swetha Suresh

Bioengineering Theses - Archive

Diabetic Neuropathy is a neuropathic disorder which is associated with Diabetes Mellitus. It is known to result in lower limb ulcers which can lead to amputation. Nerve damage, microvascular dysfunctions and use of ill fitting shoes are significant causes for it. These abnormal dysfunctions can lead to Ischemia. We have used the Multimodal Hyperspectral Imaging System image areas of high pressure on the skin that correspond to pain and also to visualize vascular changes that are associated with this pain. The instrument majorly consists of near-infrared and visible charge coupled devices (CCDs), lenses, liquid crystal tunable filters (LCTFs) for both …


Development Of Optical Fiber Sensors For Distance, Refractive Index And Strain Measurement, Ayan Majumdar Jan 2008

Development Of Optical Fiber Sensors For Distance, Refractive Index And Strain Measurement, Ayan Majumdar

Mechanical and Aerospace Engineering Theses - Archive

This thesis is focused on the development of optical fiber based sensors for the measurement of distance, refractive index, and strain. The fabrication, implementation, analysis, and evaluation of the sensors are presented. The Extrinsic Fabry-Perot Interferometric (EFPI) distance sensor is one of the most popular distance sensors but it possesses an inherent drawback. When the free-space cavity distance is very small, the numbers of fringes generated are not sufficient for the distance demodulation algorithm; therefore the smallest distance it can measure is determined by the bandwidth of the light source. An optical fiber based distance sensor is developed in this …


A Process For Ice Detector Placement Using 3-D Eulerian Droplet Impingement Analysis, Glenn T. Lancaster Jan 2008

A Process For Ice Detector Placement Using 3-D Eulerian Droplet Impingement Analysis, Glenn T. Lancaster

Mechanical and Aerospace Engineering Theses - Archive

Ice detectors invoke an aircraft's ice protection systems, which reduce the risks of flight into known icing conditions. A process has been developed to place ice detectors on aircraft using high fidelity computational icing tools. Three-dimensional Eulerian droplet impingement analysis is used to determine the necessary ice detector height and location required to achieve full functionality. This method is applied to the V-22 Osprey tiltrotor aircraft for validation against both tunnel and flight test data. When compared to icing tunnel test data, computational results for the volume of ice accreted on an antenna were within ten percent, validating the computational …


Detect: Developing Sustainable Pathways Towards Innovative, Sustainable Collaboration Between Four Engineering, Design And Technology Education Institutions, Michael Dyrenfurth, Mike Murphy, Donal Mchale, Richard Hayes, Robert Herrick, Dhushy Sathianathan, Heinz Schmidt-Walter, Eugene Coyle, Robert Simpson Jan 2008

Detect: Developing Sustainable Pathways Towards Innovative, Sustainable Collaboration Between Four Engineering, Design And Technology Education Institutions, Michael Dyrenfurth, Mike Murphy, Donal Mchale, Richard Hayes, Robert Herrick, Dhushy Sathianathan, Heinz Schmidt-Walter, Eugene Coyle, Robert Simpson

Conference papers

No abstract provided.


Philosophy Matters In Engineering Studies, William Grimson, Mike Murphy, Steen Hyldgaard Christensen, Erik Erno-Kjolhede Jan 2008

Philosophy Matters In Engineering Studies, William Grimson, Mike Murphy, Steen Hyldgaard Christensen, Erik Erno-Kjolhede

Conference papers

This article explores the rationale for including in an integrated five-years Masters Engineering programme liberal arts subjects, in particular Philosophy and the History of Science and Technology. We argue that the tools of philosophy should be used to provide additional insight into how engineering was and is 'performed'. We first review the challenge, next we present some results of an empirical case study carried out at AU-IBT in Denmark. The purpose of the case study was to examine a sample of engineering teachers´ attitudes towards the relevance and scope of liberal arts subjects for engineering students. Finally we conclude with …


Electro-Optic And Dielectric Study Of The De Vries-Type Smectic A* Phase Exhibiting Transitions To Smectic-C*A And Smectic-C* Phases, U. Manna, Jang-Kun Song, Yuri Panarin, Atsuo Fukuda, J. K. Vij Jan 2008

Electro-Optic And Dielectric Study Of The De Vries-Type Smectic A* Phase Exhibiting Transitions To Smectic-C*A And Smectic-C* Phases, U. Manna, Jang-Kun Song, Yuri Panarin, Atsuo Fukuda, J. K. Vij

Articles

Mixtures of different compositions of an antiferroelectric liquid crystal compound that exhibits direct smectic-A*(Sm-A*)-smectic-C*A(Sm-C*A) transition with a ferroelectric liquid crystal compound that exhibits Sm-A*-smectic-C*(Sm-C*) transition are studied using electro-optics and dielectric spectroscopy. The results of optical texture, birefringence, and the tilt angle suggest that a part of the Sm-A* phase is of de Vries type, since an increase in the tilt angle with decreasing temperature results in a reduction in the value of the birefringence in the Sm-A* phase, whereas the birefringence at Sm-A* to Sm-C* transition goes up by 12.7%. The soft mode relaxation strength, the Landau coefficient of …


Capacity Of Two-Sided Type C On Freeway With Four Lanes, Shadi Ghasemi-Majd Jan 2008

Capacity Of Two-Sided Type C On Freeway With Four Lanes, Shadi Ghasemi-Majd

Civil Engineering Theses - Archive

Weaving segments are categorized based on weaving length, configuration, number of lanes, free flow speed and weaving ratio. All these parameters affect weaving capacity. One of the objectives of this research was to extend Phong Thanh Vo's dissertation and study the relation between weaving capacity of two-sided type C on freeways with four lanes and any potential variables (mainalane demand, entrance ramp demand, exit ramp demand and weaving ratio). Micro-simulation has been used in order to analyze different capacity scenarios and the VISSIM calibrated model by Vo was used. Also, the effect of each of the VISSIM calibration parameters on …


The Effect Of Displacement Control Loading Histories On Genral Connecting Surfaces Using Finite Element Analysis, Sanjog Chandrakant Sabnis Jan 2008

The Effect Of Displacement Control Loading Histories On Genral Connecting Surfaces Using Finite Element Analysis, Sanjog Chandrakant Sabnis

Civil Engineering Theses - Archive

Displacement loading history provided by the AISC Seismic Provision 2002 is commonly used for experimental testing and analytical modeling of beam-to-column steel connection to stimulate the seismic effect. However, the basis for the above loading history is not documented in the literature. Thus, this study developed 25 cyclic load cases by varying the frequency and magnitude of the AISC-2002 loading within a predefined envelops. The 25 load cases are obtained from five different load sets in which the concept of uniform and non-uniform frequencies and amplitude are utilized. All the load cases are limited to the displacement equivalent to the …


Clay Mineral Quantification Using Gravemetric Analysis, Sarwenaj Ashraf Jan 2008

Clay Mineral Quantification Using Gravemetric Analysis, Sarwenaj Ashraf

Civil Engineering Theses - Archive

The current procedure used by the Texas Department of Transportation (TxDOT) to determine the type of stabilizer is based mainly on the Plasticity Index (PI) and the gradation of the soil. This method of stabilization does not always work because two soils with the same PIs can have very different shrink/swell potential, plastic limits or liquid limits, hence their behavior may be very different. This is mainly due to the fact that two soils that have the same PI can have very different clay mineral composition. Montmorillonite and kaolinite are the clay minerals that cause swelling/shrinking in soils.Chittoori (2008) had …


Development Of Laboratory Prototype Of A 12kva Digital Shunt Active Filter, N. G. Jayanti, Malabika Basu, Iurie Axente, Kevin Gaughan, Michael Conlon Jan 2008

Development Of Laboratory Prototype Of A 12kva Digital Shunt Active Filter, N. G. Jayanti, Malabika Basu, Iurie Axente, Kevin Gaughan, Michael Conlon

Conference papers

The paper reports the development of a laboratory prototype of a fully digital DSP controlled 12 kVA Shunt Active Filter (ShAF) capable of compensating for non-linear, unbalanced load and reactive power. A fully digital controller is implemented for the reference generation and the current control purposes. The delay problem in digital current controller is overcome by application of a fast DSP, a compact controller and proper flow of control steps in the DSP software. A Phase Locked Loop (PLL)-less software grid synchronization method has been proposed for the effective operation of the ShAF under the grid frequency variation. The source …


Comparison Of The Effectiveness Of Alternative Ferrate (Vi) Synthesis Formulas As Disinfectants For Wastewater And River Water, Rachelle Ginart Jan 2008

Comparison Of The Effectiveness Of Alternative Ferrate (Vi) Synthesis Formulas As Disinfectants For Wastewater And River Water, Rachelle Ginart

Electronic Theses and Dissertations

Ferrate (VI) has been studied as an alternative chemical to disinfect water and wastewater in recent years. The disinfection effectiveness of two different wet oxidation ferrate (VI) synthesis formulas in wastewater and Econlockhatchee River water was evaluated. Ferrate (VI) is synthesized by addition of ferric chloride to a mixture of sodium hydroxide and calcium hypochlorite (refer to U.S. Patent 6,790,429). One ferrate (VI) synthesis formula uses below the stoichiometric requirement of hypochlorite (Low Chlorine Formula) while the other ferrate (VI) synthesis formula uses more than the stoichiometric requirement of hypochlorite (Standard Chlorine Formula). For applications requiring low chlorine residual effluent …


Design And Fabrication Of Chemiresistor Typemicro/Nano Hydrogen Gas Sensors Usinginterdigitated Electrodes, Peng Zhang Jan 2008

Design And Fabrication Of Chemiresistor Typemicro/Nano Hydrogen Gas Sensors Usinginterdigitated Electrodes, Peng Zhang

Electronic Theses and Dissertations

Hydrogen sensors have obtained increased interest with the widened application of hydrogen energy in recent years. Among them, various chemiresistor based hydrogen sensors have been studied due to their relatively simple structure and well-established detection mechanism. The recent progress in micro/nanotechnology has accelerated the development of small-scale chemical sensors. In this work, MEMS (Micro-Electro-Mechanical Systems) sensor platforms with interdigitated electrodes have been designed and fabricated. Integrating indium doped tin dioxide nanoparticles, these hydrogen sensors showed improved sensor characteristics such as sensitivity, response and selectivity at room temperature. Design parameters of interdigitated electrodes have been studied in association with sensor characteristics. …


Optimizing Dynamic Logic Realizations For Partial Reconfiguration Of Field Programmable Gate Arrays, Matthew Parris Jan 2008

Optimizing Dynamic Logic Realizations For Partial Reconfiguration Of Field Programmable Gate Arrays, Matthew Parris

Electronic Theses and Dissertations

Many digital logic applications can take advantage of the reconfiguration capability of Field Programmable Gate Arrays (FPGAs) to dynamically patch design flaws, recover from faults, or time-multiplex between functions. Partial reconfiguration is the process by which a user modifies one or more modules residing on the FPGA device independently of the others. Partial Reconfiguration reduces the granularity of reconfiguration to be a set of columns or rectangular region of the device. Decreasing the granularity of reconfiguration results in reduced configuration filesizes and, thus, reduced configuration times. When compared to one bitstream of a non-partial reconfiguration implementation, smaller modules resulting in …


Ultra-Wide Band In Communications: Performance Analysis And Enhancements, Burak Berksoy Jan 2008

Ultra-Wide Band In Communications: Performance Analysis And Enhancements, Burak Berksoy

Electronic Theses and Dissertations

Over the last ten years, Ultra-Wide Band (UWB) technology has attracted tremendous research attention. Frequency allocation of 3.1-10.6 GHz for UWB application by FCC made it apparent that UWB will be the technology for future wireless high speed communication applications. With the promise of high data rates (high channel capacity), UWB also offers advantages such as communication security, high multi-path resolution, good penetration capability, ability to coexist with other communication schemes in the same band, and finally, circuit simplicity. The theoretical advantages of UWB has made it a great candidate for short distance communications, however, UWB communications have many challenges, …


Evaluating The Impact Of Oocea's Dynamic Message Signs (Dms) On Travelers' Experience Using A Pre And Post-Deployment Survey, Jason Flick Jan 2008

Evaluating The Impact Of Oocea's Dynamic Message Signs (Dms) On Travelers' Experience Using A Pre And Post-Deployment Survey, Jason Flick

Electronic Theses and Dissertations

The purpose of this thesis was to evaluate the impact of dynamic message signs (DMS) on the Orlando-Orange County Expressway Authority (OOCEA) toll road network using a Pre and Post-Deployment DMS Survey (henceforth referred to as "pre and post-deployment survey") analysis. DMS are electronic traffic signs used on roadways to give travelers information about travel times, traffic congestion, accidents, disabled vehicles, AMBER alerts, and special events. The particular DMS referred to in this study are large rectangular signs installed over the travel lanes and these are not the portable trailer mount signs. The OOCEA have been working over the past …


Lidar In Coastal Storm Surge Modeling: Modeling Linear Raised Features, David Coggin Jan 2008

Lidar In Coastal Storm Surge Modeling: Modeling Linear Raised Features, David Coggin

Electronic Theses and Dissertations

A method for extracting linear raised features from laser scanned altimetry (LiDAR) datasets is presented. The objective is to automate the method so that elements in a coastal storm surge simulation finite element mesh might have their edges aligned along vertical terrain features. Terrain features of interest are those that are high and long enough to form a hydrodynamic impediment while being narrow enough that the features might be straddled and not modeled if element edges are not purposely aligned. These features are commonly raised roadbeds but may occur due to other manmade alterations to the terrain or natural terrain. …


Dynamic Task Allocation In Mobile Robot Systems Using Utility Funtions, Scott Vander Weide Jan 2008

Dynamic Task Allocation In Mobile Robot Systems Using Utility Funtions, Scott Vander Weide

Electronic Theses and Dissertations

We define a novel algorithm based on utility functions for dynamically allocating tasks to mobile robots in a multi-robot system. The algorithm attempts to maximize the performance of the mobile robot while minimizing inter-robot communications. The algorithm takes into consideration the proximity of the mobile robot to the task, the priority of the task, the capability required by the task, the capabilities of the mobile robot, and the rarity of the capability within the population of mobile robots. We evaluate the proposed algorithm in a simulation study and compare it to alternative approaches, including the contract net protocol, an approach …


Delay Sensitive Routing For Real Time Traffic Over Ad-Hoc Networks, Dipika Darshana Jan 2008

Delay Sensitive Routing For Real Time Traffic Over Ad-Hoc Networks, Dipika Darshana

Electronic Theses and Dissertations

Wireless ad hoc network consists of inexpensive nodes that form a mobile communication network. Due to limitations of the transmission range, the nodes rely on each other to forward packets such that messages can be delivered across the network. The selection of the path along which a packet is forwarded from the source node to the destination node is done by the routing algorithm. Most commonly used routing algorithms, though effective for non-real time applications, cannot handle real-time applications that require strict delay bounds on packet delivery. In this thesis, we propose a routing protocol that ensures timely delivery of …


A Competitive Reconfiguration Approach To Autonomous Fault Handling Using Genetic Algorithms, Kening Zhang Jan 2008

A Competitive Reconfiguration Approach To Autonomous Fault Handling Using Genetic Algorithms, Kening Zhang

Electronic Theses and Dissertations

In this dissertation, a novel self-repair approach based on Consensus Based Evaluation (CBE) for autonomous repair of SRAM-based Field Programmable Gate Arrays (FPGAs) is developed, evaluated, and refined. An initial population of functionally identical (same input-output behavior), yet physically distinct (alternative design or place-and-route realization) FPGA configurations is produced at design time. During run-time, the CBE approach ranks these alternative configurations after evaluating their discrepancy relative to the consensus formed by the population. Through runtime competition, faults in the logical resources become occluded from the visibility of subsequent FPGA operations. Meanwhile, offspring formed through crossover and mutation of faulty and …


Reducing Eddy Currents In High Magnetic Field Environments, Russell Case Jan 2008

Reducing Eddy Currents In High Magnetic Field Environments, Russell Case

Electronic Theses and Dissertations

When an electrical conducting volume is placed into the bore of an MRI undergoing an image scan, time varying magnetic gradients induce eddy currents in this conducting material. These eddy currents in turn produce a mechanical torque on this volume. It is the goal of this thesis to produce a computer simulation of eddy currents produced by placing conducting materials inside an MRI bore. The first part of the thesis establishes the physics and principles behind an MRI system along with several applications. Next, this thesis presents an analysis of eddy current effects produced on a conductor placed into an …


Bi-Directional Dcm Dc-To-Dc Converter For Hybrid Electric Vehicles, Michael Pepper Jan 2008

Bi-Directional Dcm Dc-To-Dc Converter For Hybrid Electric Vehicles, Michael Pepper

Electronic Theses and Dissertations

With the recent revival of the hybrid vehicle much advancement in power management has been made. The most popular hybrid vehicle, the hybrid electric vehicle, has many topologies developed to realize this hybrid vehicle. From these topologies, as sub set was created to define a particular group of vehicles where the converter discussed in this thesis has the most advantage. This sub set is defined by two electric sources of power coupled together at a common bus. This set up presents many unique operating conditions which can be handled seamlessly by the DC-to-DC converter when designed properly. The DC-to-DC converter …


A Reinforcement Learning Technique For Enhancing Human Behavior Models In A Context-Based Architecture, David Aihe Jan 2008

A Reinforcement Learning Technique For Enhancing Human Behavior Models In A Context-Based Architecture, David Aihe

Electronic Theses and Dissertations

A reinforcement-learning technique for enhancing human behavior models in a context-based learning architecture is presented. Prior to the introduction of this technique, human models built and developed in a Context-Based reasoning framework lacked learning capabilities. As such, their performance and quality of behavior was always limited by what the subject matter expert whose knowledge is modeled was able to articulate or demonstrate. Results from experiments performed show that subject matter experts are prone to making errors and at times they lack information on situations that are inherently necessary for the human models to behave appropriately and optimally in those situations. …


Effects Of Source Water Blending Following Treatment With Sodium Silicate As A Corrosion Inhibitor On Metal Release Within A Wat, Phillip Lintereur Jan 2008

Effects Of Source Water Blending Following Treatment With Sodium Silicate As A Corrosion Inhibitor On Metal Release Within A Wat, Phillip Lintereur

Electronic Theses and Dissertations

A study was conducted to investigate and quantify the effects of corrosion inhibitors on metal release within a pilot distribution system while varying the source water. The pilot distribution system consisted of pre-existing facilities from Taylor et al (2005). Iron, copper, and lead release data were collected during four separate phases of operation. Each phase was characterized by the particular blend ratios used during the study. A blended source water represented a water that had been derived from a consistent proportion of three different source waters. These source waters included (1) surface water treated through enhanced coagulation/sedimentation/filtration, (2) conventionally treated …


Impact Of Corrosion Inhibitor Blended Orthophosphate On Water Quality In Water Distribution Systems, Abdulrahman Alshehri Jan 2008

Impact Of Corrosion Inhibitor Blended Orthophosphate On Water Quality In Water Distribution Systems, Abdulrahman Alshehri

Electronic Theses and Dissertations

The impact of blended orthophosphate (BOP) inhibitor addition on the corrosion of iron, copper, and lead in drinking water distribution systems was studied under changing water quality environment. Release of iron, copper, and lead were monitored at varying inhibitor doses and changing blends of source waters (groundwater, surface water, and desalinated water). Solid corrosion products on pipe surfaces under BOP treatment were evaluated with surface characterization techniques. Performance of the BOP inhibitor was compared to other corrosion control strategies. Iron scales for iron and galvanized steel coupons incubated in different blended waters in the presence of BOP inhibitor were analyzed …


The Effects Of Phosphate And Silicate Inhibitors On Surface Roughness And Copper Release In Water Distribution Systems, David Macnevin Jan 2008

The Effects Of Phosphate And Silicate Inhibitors On Surface Roughness And Copper Release In Water Distribution Systems, David Macnevin

Electronic Theses and Dissertations

The effects of corrosion inhibitors on water quality and the distribution system were studied. This dissertation investigates the effect of inhibitors on iron surface roughness, copper surface roughness, and copper release. Corrosion inhibitors included blended poly/ortho phosphate, sodium orthophosphate, zinc orthophosphate, and sodium silicate. These inhibitors were added to a blend of surface water, groundwater, and desalinated brackish water. Surface roughness of galvanized iron, unlined cast iron, lined cast iron, and polyvinyl chloride was measured using pipe coupons exposed for three months. Roughness of each pipe coupon was measured with an optical surface profiler before and after exposure to inhibitors. …


Nutrient Removal From Stormwater By Using Green Sorption Media, Fahim Hossain Jan 2008

Nutrient Removal From Stormwater By Using Green Sorption Media, Fahim Hossain

Electronic Theses and Dissertations

High nitrogen and phosphorus content in storm water runoff has affected groundwater, springs and surface water by impacting ecosystem integrity and human health. Nitrate may be toxic and can cause human health problem such as methemoglobinemia, liver damage and even cancers. Phosphorus may trigger the eutrophication issues in fresh water bodies, which could result in toxic algae and eventually endanger the source of drinking waters. Sorption media with mixes of some recycled materials, such as sawdust and tire crumb, combined with sand/silt and limestone, becomes appealing for nutrient removal in environmental management. This paper presented is a specific type of …


Removal Of 2, 4-Dinitrophenol By Ferrate, Gianna Cooley Jan 2008

Removal Of 2, 4-Dinitrophenol By Ferrate, Gianna Cooley

Electronic Theses and Dissertations

Ferrate (molecular formula, FeVIO42-) has been studied increasingly since the 1970s as a disinfectant and coagulant for domestic wastewater and also as an oxidant for industrial wastewaters (Murmann and Roginson, 1974, Gilbert et al., 1978, Kazama, 1994, Jiang et al., 2002, and Sharmaet al., 2005). This research was performed to explore whether ferrate could possibly be used as chemical treatment for industrial wastewaters from plastic, chemical, dye, soap, and wood stain producing plants that contain 2, 4-Dinitrophenol (DNP). DNP is listed on the United States Environmental Protection Agency (EPA) Drinking Water Contaminant Candidate List (CCL). This list includes compounds which …


The Effectiveness Of Specifically Designed Filter Media To Reduce Nitrate And Orthophosphate In Stormwater Runoff, Mikhal Moberg Jan 2008

The Effectiveness Of Specifically Designed Filter Media To Reduce Nitrate And Orthophosphate In Stormwater Runoff, Mikhal Moberg

Electronic Theses and Dissertations

Throughout Central Florida surface water and ground water are decreasing in quantity and quality in part because of excess Nitrate and Phosphorus nutrients. Stormwater runoff serves as a medium for transport of Nitrate and Phosphorus to surface water and ground water. The goal of this experiment is assess the Nitrate and Phosphorus removal in stormwater using select media. The results of a literature search, batch test experimentation and column test experimentation are used to determine an optimal media blend that may be implemented in detention ponds to reduce Nitrate and Phosphorus. The extensive literature search revealed 32 different media that …


Performance Based Decision System In Determining Post Closure Care (Pcc) Duration In Florida Landfills, Asawari Kulkarni Jan 2008

Performance Based Decision System In Determining Post Closure Care (Pcc) Duration In Florida Landfills, Asawari Kulkarni

Electronic Theses and Dissertations

This study is an evaluation of Post Closure Care (PCC) duration of landfills using performance based methodology. The post closure care phase begins once the landfill is closed. As required by the Resource Conservation Recovery Act (RCRA) Subtitle D, PCC duration for municipal solid waste landfills is 30 years. During the PCC period, the landfill operator/owner is required to conduct monitoring for leachate, landfill gas, and ground-water and maintain the integrity of the cap so that the landfill does not impose a threat to surrounding human health and environment (HH&E). The duration of PCC can be reduced by the director …