bluuebunny/crossref_metadata_2025 huggingface dataset:
Biomechanical comparison of suture anchor versus margin convergence plus suture anchor for rotator cuff repair
Authors: Chen Shi‐yi , Malcarney Hilary L , Murrell George A C
Published: February 2009

Objective:  To evaluate results of margin convergence versus suture anchors in rotator cuff repair, and to determine which method is mechanically superior.

Methods:  Eighteen kangaroo shoulders were randomly divided into three groups (n = 6). A full thickness tendon defect 1.0 cm × 1.5 cm in size was created in the supraspinatus tendon at humeral insertion, simulating a massive rotator cuff tear. Three different techniques were employed for rotator cuff repair: (i) Mitek GII suture anchor alone (Group 1); (ii) margin convergence alone (Group 2); and (iii) margin convergence plus Mitek GII suture anchor (Group 3). Combined loads were applied to each specimen. After completion of cyclic loading, the construct was loaded to failure. ANOVA and LSD (Least Significant Difference) multiple comparisons of the means were applied to results.

Results:  Cyclic load testing showed progressive gap formation in each repaired specimen with increasing cycles. Group 1 reached 50% failure at an average of 34 cycles, Group 2 at 75 cycles and Group 3 at 73 cycles. There were significant difference between Groups 1 and 2, and Groups 1 and 3 (P ≤ 0.001). After 100 loading cycles, the average gap size was 6.8 mm, 6.1 mm and 4.7 mm in Groups 1, 2 and 3, respectively. There was a significant difference between Groups 1 and 3 (P ≤ 0.015). All specimens eventually reached failure.

Conclusion:  Rotator cuff repairs with margin convergence +/− suture anchor were far stronger than suture anchor alone, both in gap formation and ultimate failure load. However, progressive gap formation with cyclic loading seems inevitable after cuff repair, which may facilitate clinical understanding of the phenomena of re‐tear or residual defect.
Analysis of long‐term outcomes of double‐strut bone graft for osteonecrosis of the femoral head
Authors: Wang Yi‐sheng , Yin Li , Lu Zhong‐dao , Wu Xue‐jian , Liu Hong‐jian
Published: February 2009

Objective:  To analyze the long‐term effect of double‐strut bone graft for osteonecrosis of the femoral head (ONFH).

Methods:  A total of 366 adult patients with ONFH in 466 hips underwent double‐strut bone graft from March 1988 to January 1999. Of them, 186 patients with 206 hips and an average age of 32.2 years (range, 20–60 years) were followed up for more than five years, up to January 2006. Based on the Association Research Circulation Osseous (ARCO) classification, there were 36 hips in stage IIB, and 30, 40, 40, 32 and 28 in stage IIC, IIIA, IIIB, IIIC and IV, respectively. The functional results of affected hips were evaluated by the hundred forked method.

Results:  Hip pain in all patients disappeared or alleviated greatly after the operation. The height of the femoral head improved to various extents, and the range of motion of the hip joint increased. The patients were followed up for 5–16 years, (average 10.5 years). The total scores increased significantly postoperatively (P < 0.01). The rate of excellent and good results was 83.3%, 80.0%, 75.0%, 65.0%, 40.6% and 28.6% in stage IIB, IIC, IIIA, IIIB, IIIC and IV, respectively (63.6% for the whole group).

Conclusion:  The long–term effect of double‐strut bone graft for ONFH is satisfactory in relation to staging of ONFH. Favorable results can be expected in young ONFH patients in stage IIB, IIC, and IIIA, IIIB.
Hepatozoonosis in a dog with skeletal involvement and meningoencephalomyelitis
Authors: Marchetti Veronica , Lubas George , Baneth Gad , Modenato Mario , Mancianti Francesca
Published: February 2009

Abstract: A 15‐month‐old, female mongrel dog was presented with a 6‐week history of inappetence, weight loss, and tetraparesis. Physical examination revealed weakness, poor body condition, mild fever, pale mucous membranes, and diffuse muscle atrophy. The right hind limb was painful and edematous, with large ecchymoses. The femur was irregular on palpation and moderate popliteal lymphadenopathy was evident. Results of a CBC showed severe anemia with mild regeneration, an inflammatory leukogram with 90% of neutrophils parasitized by Hepatozoon sp. gamonts, and moderate thrombocytopenia. A bone marrow aspirate had myeloid hyperplasia and contained a few extracellular Hepatozoon meronts and a few intracellular gamonts within neutrophils. Serum chemistry abnormalities included hypoalbuminemia, hyperglobulinemia, hypoglycemia, hypercalcemia, hyperphosphatemia, and elevated alkaline phosphatase activity. Radiologic findings of the right femur included periosteal bone proliferation and lesions compatible with osteomyelitis. A fine needle aspirate specimen from the bone lesion had neutrophilic inflammation; 36% of the neutrophils contained Hepatozoon gamonts. Results of cerebrospinal fluid analysis included a protein concentration of 37 mg/dL and marked mononuclear pleocytosis (243 cell/μL) with a predominance of lymphocytes. An ELISA was positive for Hepatozoon canis and PCR results with DNA sequencing confirmed infection with this organism. A diagnosis of hepatozoonosis with skeletal involvement and meningoencephalomyelitis was made. The dog recovered almost completely neurologically and had no gamonts in the blood after 60 days of therapy with imidocarb dipropionate and prednisone. This is an unusual case of canine hepatozoonosis involving neurologic signs and a periosteal reaction more typical of H. americanum infection and rarely reported in dogs infected with H. canis.
Canine elliptocytosis due to a mutant β‐spectrin
Authors: Di Terlizzi Roberta , Gallagher Patrick G. , Mohandas Narla , Steiner Laurie A. , Dolce Karen S. , Guo Xinhua , Wilkerson Melinda J. , Stockham Steven L.
Published: February 2009

Abstract: A 5‐year‐old, spayed female, mixed‐breed dog with persistent elliptocytosis was evaluated at the Veterinary Medical Teaching Hospital at Kansas State University. The elliptocytosis was asymptomatic and was detected during the evaluation of lameness. When subjected to shear stress in an ektacytometer, the dog's erythrocytes had reduced cellular deformability and erythrocyte membranes had decreased mechanical stability. Analysis of erythrocyte membrane spectrin by nondenaturing gel electrophoresis revealed an increased amount of spectrin dimers, indicating a defect in spectrin self‐association. DNA analysis detected a β‐spectrin mutation in codon 2110 in which threonine was replaced by methionine. This mutation likely altered the molecular structure of the erythrocyte membrane, leading to impaired spectrin self‐association and elliptocyte formation.
Finite Element Modeling of the Left Atrium to Facilitate the Design of an Endoscopic Atrial Retractor
Authors: Jernigan S. R. , Buckner G. D. , Eischen J. W. , Cormier D. R.
Published: February 2009

A finite element model of the left atrium, incorporating detailed anatomical features and realistic material characteristics, was built to investigate the interaction of heart tissue and surgical instruments. This model was used to facilitate the design of an endoscopically deployable atrial retractor for use in minimally invasive, robotically assisted (MIRA) mitral valve repair. The left atrial geometry was imported directly from MRI data of an explanted porcine heart, and material properties were derived from experimental testing of cardiac tissues. Model accuracy was verified by comparing simulated cardiac wall deflections to those measured by MRI. Finite element analysis was shown to be an effective tool for analyzing instrument/tissue interactions and for designing surgical instruments.
Analytical Porous Media Model of Light Penetration in Photodynamic Therapy
Authors: Premasiri Amaranath , Happawana Gemunu , Rosen Arye
Published: February 2009

Photodynamic therapy (PDT) is currently being developed as a new therapeutic modality with minimal side effects in the treatment of many different types of cancers [1]. PDT requires three essential components, which includes a photosensitizing agent, activation light, and molecular oxygen [2, 3]. Light is one of the governing components for PDT, and the only component that can be controlled externally [4]. The understanding of light penetration in a tumor is critical for an efficient PDT protocol. A well-designed PDT protocol provides minimal microvascular damage and efficient killing of malignant tumor cells [5–7]. The depth of light penetration in a tumor depends on the microvascular nature of the tumor, amount of solid and liquid contents present, and the wavelength of the light source. The first two factors depend on the nature of the tumor tissue and therefore the optimal light dose is not standard for all tumors. Furthermore the liquid content of a tumor changes with the tumor temperature due to vasodilatation, and this in turn affects the depth of light penetration.
Biomechanics of Stent Grafts for Intracranial Aneurysm Repair
Authors: Gu Linxia , Santra Swadeshmukul , Kumar Ashok V.
Published: February 2009

General non-invasive endovascular procedures for treatment of intracranial aneurysms involve stenting across the aneurysm neck, embolization and coiling of the aneurysm cavity. However it cannot be used to treat many wide-necked and fusiform intracranial aneurysms, or carotid-cavernous fistulae. Stent grafts will have the capability of completely preventing the blood flow into the aneurysm cavity or fistula rent, and thereby reducing the risk of aneurysm rupture in the brain. An endovascular approach of placing a stent graft would be a promising method [1–3].
Ultrasonic System for Diagnosis of Functional Gastrointestinal Disorders: Development, Verification and Clinical Trials
Authors: Lee Q. J. , Park W. P. , Lim D. , Woo D. G. , Ko C. Y. , Lee D. H. , Lee Y. H. , Kim H. S. , Yoon H. R. , Shin T. M.
Published: February 2009

The number of people who are suffering from Functional gastrointestinal disorders is increasing. There are, however, rare diagnostic methods for the functional gastrointestinal disorders because functional disorders show no evidence of organic and physical causes [1, 2]. Recently our research group identified that the gastrointestinal tract well in the patients with the functional gastrointestinal disorders is more rigid than healthy people. we noticed it with palpating the abdominal regions overlaying the gastrointestinal tract. Therefore we developed a system to detect the rigid organs with ultrasonic technique, which can quantify the characteristic above related to the rigidity of the gastrointestinal tract well.
Long-Term Reliability of Solder Joints on Wafer-Level Packaged Accelerometer for Medical Applications
Authors: Kwa Tom , Teutsch Thorsten
Published: February 2009

Miniaturization of devices is driving replacement of electronic components with surface mount technology (SMT) equivalent parts, including any embedded sensing devices. In many cases the size of the sensor is restricted by the minimum size of the package rather than by the die. Other solutions to preserve real-estate involve manual mounting of the die onto substrates that have gone through an SMT assembly process. The +/-2g accelerometer presented here is, to our knowledge, the first wafer-level packaged device with solderable terminals that allows the silicon die to be mounted directly onto a substrate in a standard SMT process and without the need for stressisolating interposers. With its small footprint and ceiling requirements (2.1 × 2.9 × 0.8 mm3), and robustness and high performance it is the smallest commercially-available packaged accelerometer suitable for medical applications where these characteristics are critical. The device features terminals that are electrically and mechanically separated but robust enough to withstand large shear forces that may occur during use and board assembly. The device was solder mounted on a variety of substrates without affecting its performance. Most significantly, both device and solder joints were able to withstand extended thermal cycling over a wide temperature range (-55 to 125°C). In this paper, we present the device design, the performance and the long-term reliability test results of this novel and high-performance device on a variety of substrates and solder materials.
SEM Validation Technique for FEA of Small Specimens
Authors: Pike Kelly , Lin Z. C. , Tahran Alan
Published: February 2009

The use of the SEM to make direct surface measurements on small test specimens enables the FEA analyst to construct and validate an individual specimen model. The technique is also valuable to engineers so that they can calibrate their fatigue test samples before and after fatigue test regimes.
Biomimetic Tactile Sensor
Authors: Wettels Nicholas , Popovic Djordje , Loeb Gerald E.
Published: February 2009

The performance of prosthetic hands and robotic manipulators is severely limited by their having little or no tactile information compared to the human hand. Technologies such as MEMS, microfluidics, and nanoparticles have been used to produce arrays of force sensors, but these are generally not robust enough to mount on curved, deformable finger pads or to use in environments that include dust, fluids, sharp edges and wide temperature swings. Furthermore, it is not clear how the prosthetic controller will use the tactile information, so it is difficult to generate specifications for these sensors.
Inverse Heat Transfer Analysis of Micro Heater Strength and Locations for Hyperthermia Treatment of Brain Tumors
Authors: Biniazan Maral , Mohseni Kamran
Published: February 2009

Hyperthermia, also called thermal therapy or thermotherapy, is a type of cancer treatment in which the aim is to maintain the surrounding healthy tissue at physiologically normal temperatures and expose the cancerous region to high temperatures between 43°C–45°C. Several methods of hyperthermia are currently under study, including local, regional, and whole-body hyperthermia. In local hyperthermia, Interstitial techniques are used to treat tumors deep within the body, such as brain tumors. heat is applied to the tumor, usually by probes or needles which are inserted into the tumor. The heat source is then inserted into the probe. Invasive interstitial heating technique offer a number of advantages over external heating approaches for localizing heat into small tumors at depth. e. g interstitial technique allows the tumor to be heated to higher temperatures than external techniques. This is why an innovative internal hyperthermia research is being conducted in the design of an implantable microheater [1]. To proceed with this research we need complete and accurate data of the strength, number and location of the micro heaters, which is the objective of this paper. The location, strength, and number of implantable micro heaters for a given tumor size is calculated by solving an Inverse Heat Transfer Problem (IHTP). First we model the direct problem by calculating the transient temperature field via Pennies bioheat transfer equation. A nonlinear least-square method, modified by addition of a regularization term, Levenberg Marquardt method is used to determine the inverse problem [2].
An Implantable Wireless Heating System for Hyperthermia Based Treatment of Brian Tumor
Authors: Mohseni Kamran
Published: February 2009

Development of an implantable wireless heating system capable of controlling the growth of malignant brain tumors is proposed by heating the tumor to hyperthermic temperatures (43–45°C) for a specified period of time. This investigation involves designing and fabricating microheaters to heat up the tumor and developing a complete system by integrating various components like pulse generator, microheaters, and wireless power transfer system. A software tool will aid the physician in the treatment planning. The software take the geometry and size of the tumor as input and provide strength and location of heaters as output. Depending on these outputs the physician can then decide the location of heaters in the tumor and the thermal dosage required to treat the patient. A minor surgery is required for implanting the system where the heaters are placed stereotactically into the brain tumor through holes made in the skull by small catheters slid. The number of required heaters depend on the tumor size. Minimal invasiveness, wireless power transfer and a scientific method to determine the location and strength of the heat sources are some of the significance of this study.
A Pull-Out Resistant Pedicle Screw for the Osteoporotic Spine
Authors: Ponnusamy Karthik , Iyer Sravisht , Hui Alex , Gupta Gaurav , Trehan Kartik , Yu Christopher , Khanna A. Jay
Published: February 2009

Pedicle screws are commonly used in spine surgery to implant and affix metal devices to the spine. These screws are most commonly associated with cases that require rod or plate implantation. Use of pedicle screws in osteoporotic patients, however, is limited because they suffer from low bone mass density (BMD). The low BMD is harmful to patients in two ways — it leads to increased incidence of spinal trauma and also prevents surgeons from instrumenting osteoporotic patients because screws do not achieve the required fixation in osteoporotic patients [1]. The risk of trauma is increased due to the brittle bone and vertebral compression fractures, resulting in spinal misalignment and increased risk of future trauma. Instrumenting these cases with rods or plates, however, is impossible because osteoporotic bone is not strong enough to “hold” pedicle screws in, i.e., prevent screws from pulling out [2, 3].
Novel Hydrogel Microfibers for Tissue Engineering
Authors: Trehan Kartik , Yu Christopher , Bakhru Sasha , Mao Hai-Quan
Published: February 2009

Cell encapsulation in hydrogels or microcapsules is one of the approaches for providing a biomimetic microenvironment to support cell survival, proliferation and functions. Microcapsules in particular have been used to improve the mass transport properties and ease of delivery through injection. More importantly, the microenvironment in hydrogels or hydrogel microcapsules can be tailored by incorporation of relevant adhesion molecules and growth factors through chemical conjugation and physical encapsulation. These functionalized hydrogels have been shown to effectively influence cell adhesion, proliferation and differentiation. In this study, we describe the preparation and characterization of a novel hydrogel fiber by polyelectrolyte complexation. This unique fiber geometry can be useful for regeneration of cylindrical tissues and for coculture of two different cell types inside and outside the fiber membrane.
Virtual Valve for Microfluidics
Authors: Xu Wei , Xue Hong , Bachman Mark , Li Guann-Pynn
Published: February 2009

Lab-on-a-Chip technology now becomes increasingly attractive due to advantages such as reduced sample size, reduced reagent consumption, shortened analysis time, potential for high throughput and automation and reduced costs, leading to the potential for manufacturing of disposable devices. On such microchip system, the ability to handling microfluid is important. Extensive microfluidic handling componets including microflow regulator, microfluidic sensor, microvalve and micropump have been reported. Although these microfluid handling methods are successful, for the polymer based microfluidic device, a simple design, easy fabrication and the ability to integrate into the microsystem lacks report. In this paper, we presented such microvalve by utilizing the hydrophobicity of the PDMS material, a popular biocompatible material widely used in microfluidic system. The valve utilized air trapped on the side wall of microchannel by a special microconcave structure design. Controlled by an external coil heater, the trapped air will be enlarged to reduce channel width and so reduce the fluid flow in the microchannel. The valve can work in on/off mode or on flow regulating mode depending on specific flow control requirement.
Interaction of Environmental Conditions: Role in the Reliability of Active Implantable Devices
Authors: Drexler Elizabeth S. , Slifka Andrew J. , Barbosa Nicholas , Drexler John W.
Published: February 2009

Environmental conditions can have major influence on the lifetimes and reliability of active implantable medical devices (e.g., neurostimulators, cochlear implants, internal cardioverter defibrillators). These environmental conditions can range from those encountered by the device in processing and production to transportation and storage to actual operation. Although one might argue that the environmental conditions found in the first two situations are harsher than those of the third, failures that result from those situations are screened before implantation. If we assume that the active medical device is in perfect operational form at the time it is implanted, it will still experience a host of environmental conditions that can affect reliability. In fact, the ultimate goal of these medical devices is to restore the patient, wherever they may reside, to normal activities. A list of some environmental conditions that may be experienced by a device implanted in a representative patient is found in Table 1.
Fluid-Structure Interaction in Bi-Leaflet Mechanical Heart Valves
Authors: Borazjani Iman , Ge Liang , Sotiropoulos Fotis , Dasi Lakshmi Prasad , Yogonathan Ajit
Published: February 2009

In this work we focus on the fluid-structure interaction (FSI) problem of a St. Jude Regent 23mm bi-leaflet mechanical heart valve (BMHV) implanted in modeled straight aorta geometry with a simplified sinus. A FSI solver based on a recently developed curvilinear grid/immersed boundary method fluid flow solver is developed. The current numerical simulation focuses on the acceleration phase within the cardiac cycle when the leaflets are opening following the incoming flow. The simulated results are compared with experimental data with regard to the leaflet kinematics as well as valve induced wake vortical structures and excellent agreement between the simulation and measurements is reported.
A Label-Free Integrated Optics Biosensor by Diffraction Grating Coupler
Authors: Lai Zhian , Wang Yuli , Sims Christopher E. , Allbritton Nancy , Bachman Mark , Li Guann-Pyng
Published: February 2009

Biosensors are analytical devices to detect biological reactions. Fluorescence labeling is the most widely used method. Labeling free methods are desired in some cases because it can save the time and effort of the labeling step and provide real-time observation for the reactions.
Intra-Operative Laryngoscopic Instrument for Characterizing Vocal Fold Viscoelasticity
Authors: Ottensmeyer Mark P. , Yip Michael , Walsh Conor J. , Kobler James B. , Heaton James T. , Zeitels Steven M.
Published: February 2009

Our society depends on communication, the most natural form of which is speech. Trauma, disease and the normal aging process will cause many to suffer degraded or lost vocal fold function, and it has been observed that this number is growing [1]. The vocal folds are the vibrating structures in the larynx that enable us to generate voice, from speech to opera singing. The vibrating portions of the folds consist of an external 0.1mm thick layer of epithelial cells, a soft, gel-like 0.5mm thick layer called the lamina propria (LP), a 0.3mm thick vocal ligament and an underlying thyroarytenoid muscle [2]. The fundamental frequency of speech in men is in the 100–150Hz range, and between 200 and 300Hz in women [3].
The Influence of Facet Fusion Strength on Instrumented Segment Range of Motion
Authors: Pfeiffer Ferris M. , Abernathie Dennis L.
Published: February 2009

Spinal fusion surgery is one of the most common surgical procedures used to alleviate lower back pain. It is estimated that between 200,000 and 300,000 spine fusion procedures performed each year in the United States [1]. There has been an increase of approximately 8% per year in the frequency of lumbar fusions in the United States since 1980 [2]. Spinal fusion is indicated for treatment of degenerative disk disease, degenerative joint disease, scoliosis, and isthmic and degenerative spondlylotisthesis when more conservative treatments have failed to achieve relief.
Multi-Axis Testing of an Elastomeric Prosthetic Lumbar Disc Compared to a Cadaveric Human Disc
Authors: Njus Glen , Price James , Parikh Anand , Chokhandre Snehal , Konicek John , Navarro Richard
Published: February 2009

As motion preservation implants begin to replace fusion devices for lumbar degenerative disc disease, preclinical mechanical testing of these devices is critical to predicting their in vivo safety and efficacy. ISO and ASTM standards committees have tried for years to develop a universal test standard for all lumbar disc implants. The eDisc, an elastomeric/titanium disc replacement, is substantially different in its mechanical performance than the Synthes ProDisc or J&J Charite disc. These discs rely on ball and socket motion about a fixed or moving center or rotation to provide motion restoration in 3 to 5 axes. In contrast, the eDisc has viscoelastic motion in 3 translation and 3 rotational directions, just as in the natural human disc.
Prototype of Microcapsule for Shock Wave Drug Delivery Systems and Its Design
Authors: Tamagawa Masaaki
Published: February 2009

This paper describes the trial of making microcapsules including a bubble for shock wave drug delivery systems, evaluation of their mechanical properties and development of new driving mechanics of the microcapsules.
Fundamental Investigations of Driving Force of Microcapsule for Drug Delivery Systems Using the Principle of Neutrophile’s Chemotaxis
Authors: Tamagawa Masaaki
Published: February 2009

This paper describes the effects of gradient of cytokine concentration on chemotaxis of neutrophile by observing the motion in liquid with adding cytokine concentration. The aim of this investigation is to distinguish the driving force by Marangoni effects from amebic motion.
A Micro/Mini Channel Based Concentrator of E. coli in Water Flow
Authors: Mayeed Mohammed S. , Al-Mekhnaqi Abdulhakeem M. , Auner Gregory W. , Newaz Golam M.
Published: February 2009

The objective of this research is to design and optimize a mini/micro-channel based concentrator of E. coli and integrate it with an acoustic wave biosensor. A computational research has been carried out using the state of the art computational software, CFD-ACE with water as bacteria bearing fluid. E. coli bacteria have been modeled as random discrete particles tracked by solving the Lagrangian equations. The design challenges are to achieve high particle to water ratio, high enough Reynolds number to avoid bacteria swimming, and various particle boundary conditions. The optimized design has achieved concentration of about an order of magnitude higher than the inlet concentration at a flow velocity much higher than the bacteria swimming speed under various particle-boundary interactions. Bypass channels have been used to separate concentrated water-particle mixture and to put this mixture directly onto the biosensor’s bacteria detecting surface for safe and precise installation of the biosensor in the fluidic chip.
High-Fidelity Medical Visualization
Authors: Meyer Joerg
Published: February 2009

Brain imaging requires high levels of precision and accuracy, especially for diagnostic or surgical applications. Histological sections represent the “gold standard” in high-resolution imaging. For high-fidelity volume renderings of stacks of histological sections image registration using linear and non-linear transformations is required. Non-invasive scanning techniques, such as MRI, CT, PET, etc., produce inherently lower resolution, but better aligned imagery. By combining invasive and non-invasive scanning techniques, the advantages of various modalities can be combined into a hybrid system which enables co-location of instantiated patient scans and high-resolution reference scans.
A Microfluidic Approach and Enhancement Towards a Colorimetric Enzyme-Linked-Immunosorbant-Assay for Diagnostic Detection of Infectious Diseases
Authors: Liao Uland , Tovar Armando , Felgner Philip , Lee Abraham P.
Published: February 2009

Accounting for more than 13 million deaths a year, infectious diseases have become the world’s biggest killer of children and young adults worldwide [1]. Diagnostic tools and technologies are vital towards identifying the presence and treatment of these diseases. Detection methods have commonly relied on DNA using polymerase-chain-reaction (PCR), however antibody methods have become popular due to growing trends in technology and detection sensitivity. ImmPORT Therapeutics, a leading group in generating infectious disease proteome microarrays, has developed multiplex systems for comprehensive analysis of immune responses to multiple infectious diseases [2]. Current microarray handling however requires conventional lab-bench methods that require whole-day processes and large amounts of user-handling confined to laboratory settings. Miniaturization of laboratory processes would provide numerous advantages in terms of cost, time, portability and multistage automation in addition to what is already offered. The proposed microfluidic device is a colorimetric enzyme-linked-immunosorbant assay (ELISA) for antibody detection of infectious agents that draws on ImmPORT Therapeutics technology with a purpose of decreasing reagent volumes and times potentially unattainable through conventional methods.
Design Method for the Balloon-Type Pneumatic Actuator Regarding a Stroke
Authors: Bae Taewoo , Saito Naoki , Saga Norihiko , Chonan Seiji
Published: February 2009

The balloon-type pneumatic actuator [1] has been proposed, the development of this actuator is advancing as the miniaturization is easy and the driving efficiency is high compared with past pneumatic actuators.
Reclaiming Electrolysis Reject Water With a Solar Still
Authors: Sadineni S. B. , Hurt R. , Halford C. K. , Boehm R. F.
Published: February 2009

Electrolysis is one sustainable pathway to hydrogen production. During this process, however, it is common to reject a large portion of the water during the pretreatment process to carry away impurities. We have been examining water-conserving approaches to this problem with low energy devices. One such approach is to couple the water purification step with a solar still, thus allowing some of the wastewater to be recycled and utilized in the hydrogen production. This paper reports on a study of a weir type solar still. A weir type solar still is an inclined solar still with the absorber plate formed to make weirs, as well as a top basin and a bottom basin. Raw water flows from the top basin through the weirs and to the bottom basin that is circulated back to the top basin by a small pump. Purified water is collected from condensate on the glass cover. The weir type solar still with 0.61 m width and 1.82 m length (net aperture area 0.97 m2) was constructed and tested for the Las Vegas weather conditions. A data acquisition system with temperature and flow rate sensors was also installed to record the transient variation of temperature and flow rate. The distillate productivity of the still with double-pane and single-pane glass covers is compared. The average distillate productivities for double-pane and single-pane glass covers were approximately 1.9 l/m2/day and 5.5 l/m2/day in the months of August and September in Las Vegas respectively. A double-pane glass reduced the productivity of a solar still significantly due to the reduced temperature difference between the raw water and the glass inner surface. The productivity of the weir type still is also compared with the basin type still tested at the same location side by side and is found that the weir type still productivity was approximately 20% higher. The quality of distillate from the still was also analyzed to verify the product will meet the purity required by electrolyzers.
Assisting in Matching Nevada Power Company’s Electrical Load Profiles With High Concentration PV Systems
Authors: Gray Allison , Boehm Robert , Stone Kenneth W. , Wood Gary , Johnson Kelly
Published: February 2009

This paper investigates how a point focus solar plant such as the Amonix High Concentration Photovoltaic (HCPV) solar system can assist in decreasing a utility’s peak demand load. Utilizing the HCPV generating system during Nevada Power Company’s (NPC), a southern Nevada electric utility, summer load period provides the basis for this investigation. NPC’s peak load occurs between June 1st and September 30th during the hours of 1:00P.M. to 7:00 P.M. The electric load profiles presented herein are representative data points collected over years 2004 and 2005. Part of the study investigated the impact of various factors such as temperature, humidity, wind, and solar insolation, upon NPC’s peak demand load and the performance of the HCPV. A main consideration of the study was to see if NPC could rely on such a solar plant to effectively reduce the peak load. A second part of this study was to investigate ways to improve the performance of a solar plant to ensure it would be a reliable contributor to decreasing the utility peak load. The focus of this part of the investigation was to review various methods of storage, where power from the HCPV could be generated and stored during off-peak periods and used to shore up the peak demand periods or even augment the amount of demand load that could be offset. Energy storage methods considered are: • Hydrogen, – Metal hydrides, – Compressed hydrogen, – Carbon nanotubes, – Glass microspheres, • Flywheels, • Compressed air energy storage, • Batteries.
Numerical Investigation on Ventilation Strategy for Laboratories: An Approach to Control Thermal Comfort and Air Quality Using Active Chilled Beams
Authors: Memarzadeh Farhad , Jiang Jane , Manning Andy
Published: February 2009

Laboratories are usually equipment intensive. The supply flow rates required to cool these laboratories are generally higher than in a less equipment intensive zone of the building. The thermal comfort of occupants in laboratories can be controlled by the choice of ventilation strategy. This study employs Computational Fluid Dynamics (CFD) simulation to assess the performance of active chilled beams in a general laboratory layout with some equipment intensive areas and the removal effectiveness of such a system. The chilled beam performance is also compared with at of ceiling diffusers. The results from this study show that the chilled beams improve thermal comfort, and they can be operated at as low as 4 ACH while maintaining very satisfactory average PPD (around 10%) in the occupied zones. The chilled beam system also improves removal effectiveness because of the inherent higher total supply flow rate that results in a better mixing in the room than ceiling diffusers. The chilled beams in the cases studied are seen to have an insignificant effect on the hood containment. As satisfactory thermal comfort and air quality can be achieved at a lower flow rate in comparison with all-air ceiling diffusers, a 14% saving is estimated in annual energy cost for cooling and ventilating a typical lab in the Washington DC area.
Application of Innovative Technologies for a Continuous Commissioning Case Study
Authors: Liu Guopeng , Liu Mingsheng
Published: February 2009

This paper demonstrates the implementation of new innovative technologies during continuous commissioning (CC) practices to improve building operations and reduce energy costs. A 46-year-old typical commercial building with a floor area of about 216,000 square feet was used as a case study building. The new technologies include a fan airflow measurement method for building pressure control and duct static pressure reset, and a recently developed pump water flow station for secondary pump control. The results show that these technologies improve building operation and maintenance and significantly reduce energy costs. The monthly average electricity savings for HVAC is more than 70% per month for the three months of the monitoring period. The total building electricity savings is 36.7% on average. The gas savings is about 48% for the two months of the monitoring period.
Supply Fan Speed Control Optimization Using a Fan Airflow Station
Authors: Liu Guopeng , Liu Mingsheng
Published: February 2009

This paper provides an overview of the typical variable speed drive (VSD) control for the supply fan in a variable airflow volume (VAV) system. Two new control methods using the fan airflow station (FAS) are presented in this paper. In the first method, the supply fan speed is controlled to maintain a constant system resistance, which is calculated based on the measured fan head, and airflow, which is calculated by the FAS. In the second method, the supply fan speed is controlled to maintain the duct static pressure set point, which is reset based on the airflow ratio measured by the FAS. The innovative methods can be applied to systems with either direct digial control (DDC) or pneumatic control boxes. The case studies show that the new control method can significantly save supply fan power and increase fan efficiency.
Energy Policy in Public Buildings: Challenges for China
Authors: Yu Zhun , Wang Songling , Xie Yingbai
Published: February 2009

The aim of this article is to interpret the essential content, analyze some important clauses as well as prompt or enhance the effective operation of the standard. The current study presents that China can be divided into five zones according to thermal design: severe cold area, cold area, hot summer cold winter area, hot summer warm winter area and temperate area. For all these regions, indoor design temperatures of heating and air-conditioning are specified in terms of various public buildings such as offices and garages. Meanwhile, shape coefficient, the ratio of surface area and volume, is put into a notable position compared with previous criterions. The most important parameter in this standard is overall heat transfer coefficient, all the calculation for building envelope, such as doors and windows, is performed based on it, moreover, the coefficient is the main point in the course of examination for designing drawings. Additionally, a new concept, trade off, is raised in this standard to protect designers’ originality. The results show that public buildings have a potential of saving 50 percent energy on building envelope, HVAC systems and lighting. The implications of the results indicate that this energy policy will play an important role on designing, building, rebuilding and extending public buildings, at the same period, more comfortable and acceptable indoor environment can be also achieved while the standard is implemented.
Infrared-Reflective Coating on Fused Silica for a Solar High-Temperature Receiver
Authors: Ro¨ger Marc , Rickers Christoph , Uhlig Ralf , Neumann Frank , Polenzky Christina
Published: February 2009

In concentrating solar power, high-temperature solar receivers can provide heat to highly efficient cycles for electricity or chemical production. Excessive heating of the fused-silica window and the resulting recrystallization are major problems of high-temperature receivers using windows. Excessive window temperatures can be avoided by applying an infrared-reflective solar-transparent coating on the fused-silica window inside. Both glass temperatures and receiver losses can be reduced. An ideal coating reflects part of the thermal spectrum (λ>2.5 μm) of the hot absorber (1100°C) back onto it without reducing solar transmittance. The examined transparent conductive oxides (TCO) involve a high solar absorptance, inhibiting their use in high-concentration solar systems. Although conventional dielectric interference filters have a low solar absorption, the reflection of solar radiation which comes from various directions is too high. It was found that only rugate filters fulfill the requirements for operation under high-flux solar radiation with different incident angles. A thermodynamic qualification simulation of the rugate coating on a window of a flat-plate receiver showed a reduction of almost 175 K in mean window temperature and 11% in receiver losses compared to an uncoated window. Finally, a first 25-μm thick rugate filter was manufactured and optically characterized. The issue of this paper is to share the work done on the choice of filter type, filter design, thermodynamic evaluation, and deposition experiments.
Integrated Static Pressure Reset With Fan Airflow Station in Dual-Duct VAV System Control
Authors: Wu Lixia , Liu Mingsheng , Wang Gang , Pang Xiufeng
Published: February 2009

Air duct static pressure is usually a control variable maintained by the supply fan for variable air volume (VAV) systems. Typically the air static pressure is set at a constant set point based on design conditions. However, under partial load conditions, terminal box dampers have to be closed more since required airflow is less than the design airflow which directly results in significantly smaller pressure loss. Thus no matter the terminal boxes are pressure dependent or pressure independent, the static pressure set point should be reset to a lower level to reduce the fan energy, the noise in the terminal boxes, and the terminal boxes malfunction. With the static pressure reset, the room condition can also be maintained better at lower fan energy consumption by minimizing simultaneous cooling and heating. This paper proposes to control the static pressure in dual-duct variable air volume systems by using supply fan variable frequency drives (VFDs) and installing hot air dampers in the hot deck. The static pressure set point is reset based on fan airflow measured by fan airflow station (FAS). With regard to affecting factors of space load, availability of terminal box damper position and space cooling demand, this integrated method has advantages over the existing measures such as fixed static pressure, static pressure reset by outside air temperature, static pressure reset by VAV box damper position and static pressure reset by cooling loop output. According to both the model analysis and case building study, it turns out that this method can significantly save fan power.
Solar Thermal Power for Large Chillers: A Feasibility Study
Authors: Shaligram Avinash G.
Published: February 2009

Centrifugal chillers using CFC’s were made in India in the capacity range from 150 TR to approximately 700 TR. Currently, there are around 500 units operating in India ranging in age from 10 to 30 years. All of these units will have to be replaced eventually since CFC’s are to be phased out by 2010 in Article 5 countries as per Montreal Protocol. The World Bank has made a detailed study of the issue and proposed a Global Chiller Replacement Project whereby the old units will be replaced by the current generation of energy-efficient chillers using non-CFC refrigerants. This paper deals with a novel, alternate proposal in which solar thermal power is used to power an electric-driven compression chiller and a heat-driven absorption chiller; as a pair of units, which would replace 2 Centrifugal chillers. The concept is found to be economically viable as a CDM project. The simple payback period works out to be 2 1/2 years. The investments required are large which can be brought down if the cost of solar concentrator is reduced.
Energy Policy and Sustainability: A Case Study Applying Energy Management Contract in China
Authors: Yu Zhun , Wang Songling
Published: February 2009

This article states the energy policies, especially Energy Management Control (EMC), and relative measurements in recent ten years in China. In order to identify the effectiveness of these energy policies in the industrial sector in China, a project using EMC on a circulation cool water system was described as well as its energy-conserving results. The results indicated that the pump head was higher than what the system needed, namely electric energy would be wasted since the output of pumps cannot match pipe resistance pressure, also, based on the test data, the system water flow was larger than the design parameter, the main reason, besides the pump head, was that the pumps cannot be adjusted effectively so that technical personnel can only meet the needs through different combination pumps, nevertheless, by this method it was impossible to adjust water flow accurately. Furthermore, the water chilling units were influenced by scaling because of the quality of circulating water, thus their resistance pressure was increased greatly. Additionally, the cooling capacity of cooling tower was also decreased and some components need to be replaced. According to problem diagnosis, corresponding measures, such as changing pumps, adopting frequency control and water treatment, were performed, and annual power consumption was reduced from 1970000 kWh to 960000 kWh while annual power rate was reduced from 1190000 yuan to 580000 yuan. The results of the present work implied that EMC can accelerate the implementation of energy conservation projects, therefore, this system is quite feasible and its development is prospective in China.
Costs of Carbon Dioxide Abatement in the United States
Authors: Rabl Ari , Rabl Veronika A. , Spadaro Joseph V. , Kreider Jan F.
Published: February 2009

We present an analysis of the costs of reducing CO2 emissions in the US in the near-term (the next ten years), by taking a bottom-up engineering-economic approach and covering a broad spectrum of technology-based abatement measures. In this meta-study technology cost-performance data are extracted from publicly available literature and “normalized” to a standard set of economic parameters and assumptions to assure consistency. Although the normalization is most complete for electric power and vehicles, the work covers buildings and industry as well. Costs of CO2 transport and sequestration are also discussed, but we have not considered emission reductions achievable by changes in the management of forest and agricultural land. Abatement costs are calculated with respect to a baseline, for which we have chosen the EIA forecast of the Annual Energy Outlook 2005. The emissions data are expressed as equivalent CO2, including CH4 and N2O; they also include upstream emissions, e.g. for fuel production. We also estimate the potential near-term emission reductions, as well as the uncertainties in abatement cost and reduction potential. The results are used to derive a supply curve, along with confidence intervals.
A Linear Parabolic Trough Solar Collector Performance Model
Authors: Qu Ming , Archer David H. , Yin Hongxi
Published: February 2009

A performance model has been programmed for a solar thermal collector based on a linear parabolic trough reflector focused on a coated absorber tube enclosed in an evacuated transparent tube: a Parabolic Trough Solar Collector (PTSC). This steady state, single dimensional model is based on fundamental material and energy balances together with heat transfer correlations programmed in the Engineering Equation Solver (EES). The model considers the effects of solar intensity, incident angle, collector dimensions, material properties, fluid properties, ambient conditions, and operating conditions on the performance of the PTSC. The model has been used to size system devices, to choose proper operating conditions, and to detect possible operating problems for the solar cooling and heating system for the Intelligent Workplace (IW) at Carnegie Mellon University (CMU) in Pittsburgh. The IW installed 52 - square meter PTSCs coupled with a 16 kW absorption chiller for space cooling and heating in August of 2006. The tests on PTSC performance are now being carried out. After the model is validated by experimental data of the tests, it will be further used to improve PTSC design and to optimize system operation and control for the IW.