Delicate Equipment Research Articles

Performance Evaluation of Solar PV Integrated with Custom Power Device under Various Load Conditions

The non-linear properties and rapid switching of power electronic equipment are the primary causes of power quality issues in power systems, particularly in the power distribution systems. The widespread use of delicate equipment, which continuously pollutes the environment, is making power quality problems worse. The increasing integration of renewable energy sources into the generation mix and the decarburization of the economy have created new challenges for smart grid technology, requiring creative solutions such as energy storage systems and smart transformers. This article describes a solar photovoltaic integrated unified power quality conditioner (UPQC) that uses a deep learning method based on neural networks and a novel compensating technique. Here, two Deep Neural Network algorithms are used, one in the solar PV system to obtain the maximum power under various irradiance situations, and the other to manage the UPQC under various load conditions. When compared to the conventional UPQC based on PQ Theory, DNN-UPQC produces superior results in terms of reducing total harmonic distortion. This iterative strategy, which is focused on soft computing, provides faster convergence to the target condition while maintaining the updating weight within a predetermined limit. PV-based UPQC has been connected individually to reduce voltage sag, swell, and unbalance in variable load conditions. The system's dynamic and steady state performance are assessed by modelling it with a MATLAB-Simulink in different load condition.

Monitoring For Strain-Based Railway Structure Assessment Approach Using Optical Fibre Sensor

Railway transportation is essential and continually evolving with new technologies to achieve high efficiency and passenger safety. Monitoring railways can be challenging, especially when dealing with delicate equipment. This study outlines a basic guideline and real-time monitoring process for railway tracks, serving as precautionary measures. The research employs Fiber Bragg Grating (FBG) sensors directly attached to the railway track’s web surface, which have the potential to cause failures. Before sensor installation, several critical steps were taken to ensure the fragile FBG sensors remained intact. These steps involved preparing sensor arrangements and positioning them before installation. Additionally, a calibration test for FBG is performed using the Universal Tensile Machine (UTM) with a mild steel sample, achieving a measurement of almost 1.2 picometers/micro-strain. As a result, a shift in wavelength was successfully measured and collected, enabling the calculation of strain-stress data for the rail structure during operation. The collected data exhibited no irregularities or anomalies data, indicating the success of the monitoring process. The data obtained from a well-prepared installation greatly differs from that of an underprepared one. This study underscores the necessity of thorough preparation when handling delicate equipment like FBG sensor. Therefore, the FBG sensor has the capability to measure the strain-stress behavior of rail structures, allowing for more accurate predictive assessments to prevent rail failures.

Harmonic Mitigation for Enhancing Grid-Integrated Photo voltaic System Power Quality: A Review

With the growing integration of renewable energy sources, such solar energy systems into electrical grids, power quality issues emerge from possible harmonic distortions. This study analyzes the effectiveness of grid-integrated photovoltaic systems and discusses harmonic mitigation to improve electricity quality. Power quality can be negatively impacted by harmonic distortion due to voltage swings, higher losses, and interference with delicate equipment. As a result, efficient and dependable PV system functioning inside the grid depends on the implementation of effective mitigation techniques. We examine a range of mitigation strategies, such as hybrid solutions, active filters, and passive filters, each with unique benefits and drawbacks in terms of expense, intricacy, and efficiency. The effects of integrating PV systems on grid stability, voltage regulation, and frequency management are also covered in the article, emphasizing the significance of thorough performance analysis. The effectiveness of various harmonic mitigation techniques is assessed by modeling studies and experimental validation, taking into account variables including system efficiency, dependability, and compliance with international power quality standards. The study also looks at how grid circumstances, PV system layout, and size affect harmonic generation and mitigation needs. The research yields valuable insights that aid in the formulation of strategies aimed at improving power quality and maximizing grid-integrated photovoltaic systems' performance under various operating situations. Keywords: Renewable Energy sources, Shunt Active Power Filter, harmonics, fuzzy logic controller, PID controller.

Rapid detection of the rice false smut fungus Ustilaginoidea virens by lateral flow strip-based recombinase polymerase amplification assay

Rice false smut, caused by Ustilaginoidea virens, is a devastating disease that greatly reduces rice yield and quality. However, controlling rice false smut disease is challenging due to the unique infection mode of U. virens. Therefore, there is a need for early diagnosis and monitoring techniques to prevent the spread of this disease. Lateral flow strip-based recombinase polymerase amplification (LF-RPA) overcomes the limitations of current U. virens detection technologies, which are time-consuming, require delicate equipment, and have a high false-positive rate. In this study, we used a comparative genomics approach to identify Uv_3611, a specific gene of U. virens, as the target for the LF-RPA assay. The designed primers and probe efffectively detected the genomic DNA (gDNA) of U. virens and demonstrated no cross-reactivity with related pathogens. Under optimal conditions, the LF-RPA assay demonstrated a sensitivity of 10 pg of U. virens gDNA. Additionally, by incorporating a simplified PEG-NaOH method for plant DNA extraction, the LF-RPA assay enabled the detection of U. virens in rice spikelets within 30 min, without the need for specialized equipment. Furthermore, the LF-RPA assay successfully detected U. virens in naturally infected rice and seed samples in the field. Therefore, the LF-RPA assay is sensitive, efficient, and convenient, and could be developed as a kit for monitoring rice false smut disease in the field.

Comparison of pre- and post-surgical images of reusable and single use flexible ureteroscopes: a qualitative analysis.

IntroductionGiven the fragility of reusable ureterorenoscopes, many single use instruments have appeared on the market. Unfortunately, reuse of these scopes occurs in undeveloped countries in order to cut costs. This raises safety concerns for the patient.The aim of this article was to macroscopically evaluate the changes that single use flexible ureterorenoscopes (su-fURS) suffer after a retrograde intrarenal surgery (RIRS), and to compare them to reusable fURS.Material and methodsPre and post-operative images of the instruments used in 23 RIRS were obtained. All the cases had renal calculi of the inferior calix between 10–15 mm, and all of them were treated with Holmium laser. The ureterorenoscopes used were: Storz® Flex X2, Storz® Flex XC, Pusen® 3022, OTU® Wiscope, AnQIng® Innovex and Boston Scientific® LithoVue. Qualitative comparisons of these were made.ResultsAfter su-fURS usage, significant damage was observed, especially on the distal tip. Deflection was not compromised. Reusable fURS did not sustain any damage after their use.ConclusionsfURS are delicate equipment, especially if they are of single use. The considerable damage sustained by single use scopes could mean that reuse of these instruments is dangerous and should be avoided.

Phase inversion synthesis of Fe3O4@NC composites with superior lithium storage performance

The N-doped carbon coated Fe3O4 composites (Fe3O4@NC) are successfully fabricated on a polyacrylonitrile (PAN) phase inversion method and subsequently annealing. Compared with common electrospinning method, needing delicate equipment and strict reaction conditions, this method is facile and ingenious to synthesize PAN-based composites or carbon-coated materials. Applied to lithium ion batteries (LIBs) anode, the Fe3O4@NC composite exhibits a large specific capacity of 981 mAh g−1 at 0.2 A g−1 after 500 cycles, an outstanding rate capability and a superior long-term high-rate cycling performance (632 mAh g−1 at 1 A g−1 after 900 cycles). Its excellent electrochemical performance is attributed to the thin carbon layers on the surface of Fe3O4 nanoparticles, which can not only enhance the electron conductivity, but also buffer the volume change of Fe3O4 nanoparticles during lithiation/delithiation. Moreover, the doped nitrogen atoms derived from PAN can lead to more defects in electrode material, which benefits to the electrochemical performance of Fe3O4@NC composites.

The Competence-Oriented Teaching of Antennas, Propagation, and Wireless Communications: Enabling independent students

Competence-oriented education aims to teach individuals the cognitive skills required to solve specific problems and the readiness needed to apply such solutions in versatile situations. We find that competence-oriented teaching is a promising paradigm in applied courses for antennas, propagation, and wireless communications. Competenceoriented laboratory courses are easy to implement when the mechanical facilities and equipment from laboratory courses are already available at the institute. Amateur radio equipment is used so that students can work independently without risking damage to delicate equipment. In this article, we describe several methods used to modify lab courses toward competence-oriented academic teaching that we have found are popular with students and enhance their learning experience.

Fullerene functionalized gold nanoparticles for optical limiting of continuous wave lasers

Due to the increasingly widespread diffusion of lasers in many scientific and technological fields, the engineering and the fabrication of systems able to protect either human eyes or delicate equipment from laser radiation damage is nowadays attracting lots of interest in the scientific community. In this work, the optical limiting properties of fulleropyrrolidine, gold nanoparticles and hybrid systems in solution and in a polycarbonate matrix are investigated using a continuous wave laser at 514 nm, by optical limiting, Z-scan and temporal response measurements. The comparison of the results, obtained with different techniques, has allowed us to show that thermal effects account for most of the nonlinear response in gold nanoparticles and in the hybrid system; moreover, the latter exhibits a lower nonlinear threshold and a faster response compared to the former. This paper provides a contribution to the engineering of efficient protection devices in the continuous wave regime.

Excited-State Absorption from Real-Time Time-Dependent Density Functional Theory: Optical Limiting in Zinc Phthalocyanine.

Optical-limiting materials are capable of attenuating light to protect delicate equipment from high-intensity light sources. Phthalocyanines have attracted a lot of attention for optical-limiting applications due to their versatility and large nonlinear absorption. With excited-state absorption (ESA) being the primary mechanism for optical limiting behavior in phthalocyanines, the ability to tune the optical absorption of ground and excited states in phthalocyanines would allow for the development of advanced optical limiters. We recently developed a method for the calculation of ESA based on real-time time-dependent density functional theory propagation of an excited-state density. In this work, we apply the approach to zinc phthalocyanine, demonstrating the ability of our method to efficiently identify the optical limiting potential of a molecular complex.

Unconventional Rock Defies Old Rules, but New Rules are Far From Being Ready

Conference review - 2015 Unconventional Resources Technology Conference The label unconventional oil and gas stubbornly hangs on because these formations cannot be understood using the rules of conventional petroleum engineering. To illustrate what makes it so different, Erdal Ozkan, a professor of petroleum engineering at Colorado School of Mines, pointed out that shale is often so tight that “you do not want to count the zeros” needed to measure the infinitesimally small permeability rate, and the pressure needed to force oil out sounds unattainably high. The obvious conclusion is “you cannot produce any of this. How could you with this permeability? What are you doing, day dreaming? We are actually producing from these formations,” he said. Ozkan used that observation to introduce a session at the 2015 Unconventional Resources Technology Conference in San Antonio, Texas, on the need to think “outside the conventional reservoir engineering perceptions.” That is a starting point to getting significantly more out of unconventional formations. The four panel members focused on the need for a better understanding of the physics and chemistry of nanoscale pore spaces. Among their concerns is the major impact that miniscule pore throats can have on how much oil and gas is produced and what sort of hydrocarbons come out. These passages perform like a membrane, allowing natural gas liquids and gas dissolved in oil to get out, while trapping heavier oil molecules and perhaps free natural gas adhering on the pore walls, he said. Beyond 10% The message was that years of research will be needed to understand the rock and find ways to extract the oil and gas trapped inside. Research laboratories are still seeking ways to simulate reservoir conditions in ways that can be observed using delicate laboratory equipment. Low oil prices have apparently pushed thoughts of enhanced oil recovery (EOR) out of the minds of oil industry decision makers. Sustaining high levels of unconventional oil production in future decades will require producers to push ultimate recoveries past 10% of the oil in these formations. “You better start working on this pretty soon because it will take a while to figure this out,” said Paul Leonard, manager of reservoir technology for Pioneer Natural Resources, before asking if production could be enhanced using chemicals. The answer was that EOR using chemicals is being tested in research laboratories with some success. But what is known has to be adapted to formations that are poorly described by the current vocabulary for rock properties. A few surfactants have proved promising in tests, said Mohammad Piri, a distinguished associate professor of petroleum engineering at the University of Wyoming. Those tests, which will be detailed in an upcoming paper, are an outgrowth of fundamental work on whether shale is prone to attract water or oil, which would mean it is either water-wet or oil-wet. The answer has been both. When a tiny sample, which has been cleaned using air, is exposed to brine and then oil, the salty water adheres to certain sections of the rock and the oil to others. For Piri, the challenge has been to find a chemical that allows the rock to release the oil in the oil-wet area, without changing the valuable water-wet properties. While he said there have been some promising surfactants identified, it is early work.

Building a Better Redox Flow Battery - Innovative Diagnostics to Visualise Reactant Transport

While the optimization of PEMFCs and RFBs require addressing multiple issues, both systems share an operation mechanism based on pumping a fluid (a gas or a liquid) containing chemically reactive species across the face of an electrode. As a consequence of this characteristic, a significant source of inefficiency is linked to mass transport limitations including high pressure drop or inhomogeneous reactant flow distribution across the electrode. Previously, strategies including infrared mapping, (1) magnetic resonance imaging (2) or neutron radiography (3) were employed in an attempt to investigate fluid transport phenomena (predominantly for fuel cells). However, although those studies rendered valuable results, the measuring procedures can be considered as expensive and require delicate equipment. In this contribution, a simple and low cost methodology to study the mass transport processes in RFBs is presented. This approach relies on the instantaneous electrochemiluminescence of Luminol. By simply recording the emitted light with a low cost camera,(4) concentration profiles at the surface of the electrode were obtained presenting high temporal and spatial resolutions. In addition, modifications on the electrolyte formulation and flow rate permitted identifying turbulent flow areas located at the turn of the flow field as well as leading to the design of improved components.

Building a Better Redox Flow Battery - Innovative Diagnostics to Visualise Reactant Transport

While the optimization of PEMFCs and RFBs require addressing multiple issues, both systems share an operation mechanism based on pumping a fluid (a gas or a liquid) containing chemically reactive species across the face of an electrode. As a consequence of this characteristic, a significant source of inefficiency is linked to mass transport limitations including high pressure drop or inhomogeneous reactant flow distribution across the electrode. Previously, strategies including infrared mapping, (1) magnetic resonance imaging (2) or neutron radiography (3) were employed in an attempt to investigate fluid transport phenomena (predominantly for fuel cells). However, although those studies rendered valuable results, the measuring procedures can be considered as expensive and require delicate equipment. In this contribution, a simple and low cost methodology to study the mass transport processes in RFBs is presented. This approach relies on the instantaneous electrochemiluminescence of Luminol. By simply recording the emitted light with a low cost camera,(4) concentration profiles at the surface of the electrode were obtained presenting high temporal and spatial resolutions. In addition, modifications on the electrolyte formulation and flow rate permitted identifying turbulent flow areas located at the turn of the flow field (Fig. 1) as well as leading to the design of improved components.

Review: Confronting the Chaos A Rogue Historian Returns to Afghanistan

CONFRONTING THE CHAOS A Rogue Historian Returns to Afghanistan Sean M. Annapolis: Naval Institute Press, 2009. 256 pp, US$34.95 cloth. ISBN 978-1-59114-508-0The first time I met Sean we were both hunkered down behind a plywood and sandbag abutment at the US aviation shack on Kandahar airfield trying to reap what shade we could find from the pitiless Afghan sun. We were waiting for a CH-47 Chinook transport helicopter to take us north where, as it turned out, we were both attending a shura at the newly opened Canadian forward operating base the Sha WaIi Kot district. I learned first hand listening to Maloney s musings that he was a historian of a different stripe and this was far from the first of his helicopter sojourns over this antique land. His new book, Confronting the Chaos, is vintage that it is infused with unvarnished opinion and insight based on handson research and time in country. This book is the second of what will be a trilogy bundling Maloney1 s many visits to the Afghan theatre. It focuses on the events of 2003 through 2005, ending with the international security assistance force's expansion into Afghanistan's troubled southern region. The final instalment will open with the commencement of Canadian combat operations this region March 2006. And what a rich repository of recollection and nuance the completed trilogy will comprise.This latest effort contains much that military historians and veterans will want to harvest: clipped conversations with players what describes as the chess game of contemporary Afghanistan; insight into the thoughts and opinions of the key players inside the NATO force; and impressions felt and experienced and impossible to glean from secondary sources and remote study. Consider this reflection on the Tobyhanna army depot forward repair faculty at Bagram, a veritable bone yard of replacement war machines of the contemporary battlefield:It was totally surreal. Warfare the information age was impossible without photocopiers, printers, hard drives, and modems.... The environment gave a beating to the delicate equipment originally designed and built for an insurance company Ohio or a lawyer's office Maine. These machines were war-weary, their silicon hearts pushed to the limits by the war Afghanistan (64).In his examination of the period from 2003 to 2005, has ventured where few scholars and writers have dared. In informed detail, he explores the early history of both operation Enduring Freedom and the NATO missions Afghanistan. His sense of chronology and attention to nuance the creation of combined forces command-Afghanistan, for example, and the description of Major General Andy Leslie and Ambassador Chris Alexander's steerage Kabul are intriguing. His writing has an edge and literary swagger.Before becoming an academic, attended the Royal Military College of Canada and logged time as an army subaltern. …

Nucleic acid testing (NAT) in high prevalence–low resource settings

Blood screening by NAT for major transfusion transmitted viral infections (TTIs) was originally intended to complement serology for detection of infected donations. Reports from developed countries showed limited marginal value to NAT blood screening in improving blood safety. Reports on NAT results from Europe indicated yield of 1:0.6 million donations for HBV, <1:M for HCV and HIV-1-related to low prevalence of TTI. In contrast, prevalence of TTI in resource-limited countries is almost always high. As a result, more incident cases can be expected among first-time blood donors. Most reports of NAT blood donation screening in these countries showed NAT confirmed yield as high as 1/2800 for HBV and 1/3100 blood donations for HCV as reported from Thailand and Egypt, respectively. The issues for low resource countries are mostly the high cost of NAT but also the requirements of staff qualification, adequate facilities, reagent procurement and maintenance of delicate equipment. Alternatives to commercial NAT are the use of combos antigen-antibody for HIV and HCV, anti-HBc for HBV and in-house NAT. Most of these alternatives have been reported but very few comparisons are available. Once yield data is available, models for estimation of feasibility and cost-effectiveness are proposed to help decision-making.

An innovative isolation bearing for motion-sensitive equipment

Seismic isolation can protect delicate equipment housed in structures under earthquake attacks. One of the common approaches to isolate equipments is by using isolated secondary raised floors on which the equipments are mounted. This paper presents a new rolling-based seismic isolation bearing, referred to as roll-n-cage (RNC) isolator, for motion-sensitive equipment protection using the raised-floor approach. The RNC isolator is described, modeled and characterized. The effectiveness of the RNC isolator is numerically assessed considering the case of equipment housed in upper floors of a building, where the accelerations are amplified and the motion contains strong components at long periods. The numerical results reveal that the proposed RNC isolator device can attenuate seismic responses effectively under different ground motion excitations while exhibiting robust performance for a wide range of structure–equipment systems.

Development and inheritance of molecular markers in the kelp bass Paralabrax clathratus

Keywords Mendelian Microsatellite Mitochondrial Paralabrax SerranidaeWhile molecular tools have transformed fisheries biology,their development and implementation can necessitate theuse of delicate equipment, be expensive, and requireextensive optimization [1]. Counting only consumables, wehave calculated that in-house sequencing of 500–700 baseson a Beckman CEQ 8000 (Beckman Coulter, Fullerton,CA, USA) costs *$4–5 per sample under ideal conditions.It is a process not amenable to isolated or rudimentary labconditions and is not easily performed as a quick-returnassay. Loci scored as dye-labeled fragments on an auto-mated sequencer are also expensive [2]; they requiredevelopment of a microsatellite library and cost commer-cially *US$12,500 [3]. Confirmation of Mendelianinheritance in the marker set is yet another cost burden andrepresents an important but infrequently performed pre-requisite for statistical testing. A recent survey found 1 in15 microsatellite loci, as expressed in their data scores, hadnon-Mendelian patterns [4].The reporting of methodologies and inheritance studiesthat are cost effective and have minimal equipmentrequirements can therefore be invaluable to a new researchprogram or a monitoring effort that requires fast turn-around times. A set of markers will be available for thespecies in question and frequently its congeners; thestrategies for developing the markers, such as our inheri-tance methodology below, can have even widerapplication. Based on this rationale, this short paper pre-sents genetic methods developed for the kelp bass,Paralabrax clathratus, that confirm the robustness ofmarkers and allow for economical and expeditious assays.Kelp bass are a temperate serranid found abundantly fromPoint Conception, CA, to just south of Punta Eugenia,Mexico [5], and are an important component of the$300 million California sport fishing industry [6, 7]. P.clathratus occurs in current and proposed southern Cali-fornia marine reserves and has been the subject of adiversity of research [8–11].We document a restriction fragment length polymor-phism (RFLP) assay of the mitochondrial control regionthat can assess a substantial amount of the sequencediversity with only a thermal cycler and an agarose gel box.We also present a series of controlled crosses to confirmMendelian inheritance for previously published microsat-ellite markers [12], a task generally difficult to performwith many marine fish [13].Development of RFLPsSequences for the mitochondrial control region of 105 kelpbass from ten locations (Genbank accession numbersDQ192295–DQ192399) were used. Sequences werealigned in Sequencher 4.5 (Gene Codes, Ann Arbor, MI,USA) and surveyed with the program’s restriction enzymelibrary. Pairwise U

Vehicle-track-underground modeling of rail induced wave propagation

A moving rail vehicle may cause propagating waves to the surroundings potentially leading to detrimental effects for the track construction, nuisances for the surroundings and interference with delicate electronic equipment. A full computational model should be able to couple a correct simulation of the rigid body motion of the different train parts with accurate prediction of the solid wave propagation in the ground. This paper integrates the dynamics of the vehicle and the elastic soil into one monolithic system. Equations of motion for the train have been merged the system representing the FEM problem for the rest of the structure. Three models of modern high-speed locomotives were run over a solid finite element model of a rail structure.

A stone extraction facilitation device to achieve an improved technique for performing LCBDE

Laparoscopic common bile duct exploration (LCBDE) has proved to be a safe, cost-effective way to treat common bile duct (CBD) stones. Despite this, LCBDE has not gained widespread adoption by surgeons. The technique has proved difficult to master, and damage to the fragile choledochoscope by grasping forceps and passage through the port valves has been problematic. Cases involving large, impacted, or multiple stones have required conversion to open exploration of CBD. The Multichannel Instrument Guide (MIG) is introduced as a solution for these problems. The MIG is a J-shaped plastic extrusion with three lumens. It is flexible and can be straightened for insertion through a 10-mm port. The MIG facilitates insertion of a flexible 2.8- to 3.2-mm choledochoscope into the CBD. At the same time, additional tools such as balloon or irrigation catheters and lithotripters can be introduced into the CBD. These can be manipulated under video guidance via the choledochoscope. This procedural multitasking allows for a more efficient LCBDE. The authors describe their initial experience using the MIG for 23 patients. Of the 23 patients who underwent LCBDE procedures, 20 had stones in the CBD. Multiple stones were present in 48% of the patients; impacted stones were present in 26% of the patients; and stones larger than 1 cm were present in 26% of the patients. A 95% stone clearance rate was achieved. Difficult cases with large, impacted or multiple stones were resolved using the MIG. Two choledochoscopes were damaged; one during surgery and one during cleaning and storage. The MIG has demonstrated significant advantages over previously described techniques. The device secures biliary tract access and allows procedural multitasking while protecting the delicate and expensive equipment. Subsequently, a simplified technique algorithm can be followed that may encourage more surgeons to adopt the routine performance of LCBDE.

Optimal switchover times between two activities utilizing the same resource

AbstractThe “gold‐mining” decision problem is concerned with the efficient utilization of a delicate mining equipment working in a number of different mines. Richard Bellman was the first to consider this type of a problem. The solution found by Bellman for the finite‐horizon, continuous‐time version of the problem with two mines is not overly realistic since he assumed that fractional parts of the same mining equipment could be used in different mines and this fraction could change instantaneously. In this paper, we provide some extensions to this model in order to produce more operational and realistic solutions. Our first model is concerned with developing an operational policy where the equipment may be switched from one mine to the other at most once during a finite horizon. In the next extension we incorporate a cost component in the objective function and assume that the horizon length is not fixed but it is the second decision variable. Structural properties of the optimal solutions are obtained using nonlinear programming. Each model and its solution is illustrated with a numerical example. The models developed here may have potential applications in other areas including production of items requiring the same machine or choosing a sequence of activities requiring the same resource. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 186–203, 2002; DOI 10.1002/nav.10008

Feedback Stability Limits for Active Isolation Systems with Reactive and Inertial Actuators

Some of the compromises inherent in using a passive system to isolate delicate equipment from base vibration can be avoided using fully active skyhook damping. Ideally, a secondary force, which is made proportional to the absolute equipment velocity by a feedback controller, acts only on the equipment and so the response of the system under control, between the secondary force input and the collocated velocity output, i.e., the plant response, is proportional to the driving point mobility of the mounted equipment. The frequency response of the plant is guaranteed to have a positive real part under these ideal conditions, and so the feedback system is unconditionally stable for any positive real feedback gain. In practice, the actuator generating the secondary force must either react off the base structure or an inertial mass. In both of these cases the plant response is no longer guaranteed to be positive real and so the control system may become unstable at high gains. Expressions for the overall plant responses are derived for both of these arrangements, in terms of the dynamic response of the individual parts of the isolation system. When using a soft mount, the stability of the reactive system is found to be surprisingly tolerant of the additional contributions to the plant response from the reactive force. In order for the inertial system to be stable with a high feedback gain, however, the natural frequency of the actuator must be well below the natural frequency of the equipment on the mounts. Experimentally measured plant responses are compared with those predicted from theory for both types of actuator and the performance of practically implemented feedback controllers is discussed.