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Sample records for carbon based prosthetic

  1. Carbon based prosthetic devices

    Energy Technology Data Exchange (ETDEWEB)

    Devlin, D.J.; Carroll, D.W.; Barbero, R.S.; Archuleta, T. [Los Alamos National Lab., NM (US); Klawitter, J.J.; Ogilvie, W.; Strzepa, P. [Ascension Orthopedics (US); Cook, S.D. [Tulane Univ., New Orleans, LA (US). School of Medicine

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project objective was to evaluate the use of carbon/carbon-fiber-reinforced composites for use in endoprosthetic devices. The application of these materials for the metacarpophalangeal (MP) joints of the hand was investigated. Issues concerning mechanical properties, bone fixation, biocompatibility, and wear are discussed. A system consisting of fiber reinforced materials with a pyrolytic carbon matrix and diamond-like, carbon-coated wear surfaces was developed. Processes were developed for the chemical vapor infiltration (CVI) of pyrolytic carbon into porous fiber preforms with the ability to tailor the outer porosity of the device to provide a surface for bone in-growth. A method for coating diamond-like carbon (DLC) on the articulating surface by plasma-assisted chemical vapor deposition (CVD) was developed. Preliminary results on mechanical properties of the composite system are discussed and initial biocompatibility studies were performed.

  2. [Survey of carbon fiber reinforced plastic orthoses and occupational and medical problems based on a questionnaire administered to companies involved in the manufacture of prosthetics and orthotics].

    Science.gov (United States)

    Kaneshiro, Yuko; Furuta, Nami; Makino, Kenichiro; Wada, Futoshi; Hachisuka, Kenji

    2011-09-01

    We surveyed carbon fiber reinforced plastic orthoses (carbon orthoses) and their associated occupational and medical problems based on a questionnaire sent to 310 companies which were members of the Japan Orthotics and Prosthetics Association. Of all the companies, 232 responded: 77 of the 232 companies dealt with ready-made carbon orthoses, 52 dealt with fabricated custom-made orthoses, and 155 did not dealt with carbon orthoses. Although the total number of custom-made carbon ortheses in Japan was 829/ 5 years, there was a difference by region, and one company fabricated only 12 (per 5 years) custom-made carbon orthoses on average. The advantages of the carbon orthosis were the fact that it was "light weight", "well-fitted", had a "good appearance", and "excellent durability", while the disadvantages were that it was "expensive", "high cost of production", of "black color", and required a "longer time for completion", and "higher fabrication techniques". From the standpoint of industrial medicine, "scattering of fine fragments of carbon fibers", "itching on the skin" and "health hazards" were indicated in companies that manufacture the orthosis. In order to make the carbon orthosis more popular, it is necessary to develop a new carbon material that is easier to fabricate at a lower cost, to improve the fabrication technique, and to resolve the occupational and medical problems.

  3. Effect of Modifying Prosthetic Socket Base Materials by Adding Nanodiamonds

    Directory of Open Access Journals (Sweden)

    Lifang Ma

    2015-01-01

    Full Text Available The curing process of prosthetic socket base materials requires attention owing to a series of associated problems that are yet to be addressed and solved. However, to date, few relevant studies have been reported. In this paper, nanodiamonds modified with a silane coupling agent were dispersed into a prosthetic socket base material, and the performance of the modified base materials was investigated. Adding a predetermined amount of nanodiamonds to the prosthetic socket base material increased the glass transition temperature, improved the mechanical properties of the cured base material, and reduced the influence of the volatile gas formed during the curing process on the environment. With increasing nanodiamond contents, the glass transition temperature increased and the mechanical properties improved slightly. Owing to the high thermal conductivity of the nanodiamonds, the localized heat, as a result of the curing process, could be dissipated and released. Thus, adding nanodiamonds led to a more uniform temperature field forming in the curing system. This improved the curing process and reduced the formation of volatile monomers, thereby decreasing the adverse impact of the generated volatile gases on the environment. All of these provide a potential strategy for modifying prosthetic socket base materials.

  4. Reconsidering evidence-based practice in prosthetic rehabilitation : a shared enterprise

    NARCIS (Netherlands)

    van Twillert, S.; Geertzen, J.; Hemminga, T.; Postema, K.; Lettinga, A.

    2013-01-01

    Background: A divide is experienced between producers and users of evidence in prosthetic rehabilitation. Objective: To discuss the complexity inherent in establishing evidence-based practice in a prosthetic rehabilitation team illustrated by the case of prosthetic prescription for elderly dysvascul

  5. [Effect of prosthesis cleansing agent on the prosthetic base fungi].

    Science.gov (United States)

    Temmer, K; Stipetić, D; Cekić-Arambasin, A; Kraljević, K

    1991-01-01

    Candida albicans and other fungi are frequently found in subjects wearing prostheses, especially in prostheses with poor hygiene, i.e. with accumulations of food, plaques and calculi. The aim of this study was to assess the efficacy of Corega extradent relative to fungi adhering to the prosthetic base. Results of the study showed the prosthesis hygiene to be substantially related to inflammation of palatal mucosa. The mean number of fungi per sq.cm of prosthetic base was 64 x 10(5). The number of fungi was redetermined after a two-day treatment with Corega extradent, with unchanged other habits of the prosthesis wearing and cleansing. The number of fungi decreased in all study subjects, the mean value of individual differences being 2238 times. In prostheses with a great number of fungi and extremely poor hygiene, the effect of Corega extradent was poorer, indicating the need of additional mechanical cleansing with a brush. PMID:1819938

  6. Optimising the prescription of prosthetic technologies (opptec): Outcome measures for evidence based prosthetic practice and use

    LENUS (Irish Health Repository)

    Ryall, Dr Nicola

    2010-01-01

    This study provided a forum for patients and service providers to voice their opinions in what they believe to be the important predictors and outcomes involved in successful rehabilitation following limb loss. To develop a consensus on the most important outcomes and factors to address for both the lower limb and upper limb prosthetic prescription process, the above data relating to lower limb and upper prosthetics were subsequently used in the next phase of the research involving two Delphi surveys of 23 and 53 experts within the lower limb and upper limb amputation and prosthetic field respectively, including users, service providers and researchers.\\r\

  7. Fiber-array based optogenetic prosthetic system for stimulation therapy

    Science.gov (United States)

    Gu, Ling; Cote, Chris; Tejeda, Hector; Mohanty, Samarendra

    2012-02-01

    Recent advent of optogenetics has enabled activation of genetically-targeted neuronal cells using low intensity blue light with high temporal precision. Since blue light is attenuated rapidly due to scattering and absorption in neural tissue, optogenetic treatment of neurological disorders may require stimulation of specific cell types in multiple regions of the brain. Further, restoration of certain neural functions (vision, and auditory etc) requires accurate spatio-temporal stimulation patterns rather than just precise temporal stimulation. In order to activate multiple regions of the central nervous system in 3D, here, we report development of an optogenetic prosthetic comprising of array of fibers coupled to independently-controllable LEDs. This design avoids direct contact of LEDs with the brain tissue and thus does not require electrical and heat isolation, which can non-specifically stimulate and damage the local brain regions. The intensity, frequency, and duty cycle of light pulses from each fiber in the array was controlled independently using an inhouse developed LabView based program interfaced with a microcontroller driving the individual LEDs. While the temporal profile of the light pulses was controlled by varying the current driving the LED, the beam profile emanating from each fiber tip could be sculpted by microfabrication of the fiber tip. The fiber array was used to stimulate neurons, expressing channelrhodopsin-2, in different locations within the brain or retina. Control of neural activity in the mice cortex, using the fiber-array based prosthetic, is evaluated from recordings made with multi-electrode array (MEA). We also report construction of a μLED array based prosthetic for spatio-temporal stimulation of cortex.

  8. Usefulness of magnetic resonance imaging for managing patients with prosthetic carbon valve in the mitral position

    Energy Technology Data Exchange (ETDEWEB)

    Koito, Hitoshi; Imai, Yuko; Suzuki, Junichi; Ohkubo, Naohiko; Nakamura, Chikako; Takahashi, Hideki; Iwasaka, Toshiji; Inada, Mitsuo [Kansai Medical School, Moriguchi, Osaka (Japan)

    1997-11-01

    The safety, findings and clinical usefulness of MR imaging were assessed in patients with a prosthetic carbon valve (CarboMedics: A, St. Jude Medical: B and Bjoerk-Shiley: C valves) in the mitral position. Little image distortion was shown in A and B, a small distortion toward the frequency encoded direction was seen in C, but caused no difficulty in assessing the surrounding images. Four of the 8 patients had normal sinus rhythm and the other four had atrial fibrillation. The prosthetic valves were depicted as signal voids in the images taken by both spin echo and field echo techniques in vivo. Clear structural information with little image distortion of the adjacent tissues of the prosthetic valves were obtained in all patients, although the image of C which contained stainless steel in the frame had a slightly stronger distortion than those of the A and B which contained titanium. The stainless wire suture material used to close the sternal incision was depicted as a signal void, and the areas of the signal loss were larger in the images taken by the field echo technique than those by the spin echo technique. The images (spin echo) in patients with atrial fibrillation had reduced quality due to the irregularity of repetition time. Cine MR imaging (field echo) showed physiological mitral regurgitant jets as signal loss within the flowing blood, which appeared as high signal intensity, bidirectionally in the bileaflet mechanical valve and unidirectionally in the monoleaflet mechanical valve. The wall of the abnormal cavity was disrupted abruptly and the rest of the wall consisted of pericardium and adjacent tissue in the images (spin echo). The images (field echo) showed an abnormal jet flow from the basal part of the left ventricular cavity into the abnormal cavity, which was compatible with left ventricular pseudoaneurysm. (K.H.)

  9. Terrain Identification for Prosthetic Knees Based on Electromyographic Signal Features

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The features of electromyographic (EMG) signals were investigated while people walking on different terrains, including up and down slopes, up and down stairs, and during level walking at different speeds. The features were used to develop a terrain identification method. The technology can be used to develop an intelligent transfemoral prosthetic limb with terrain identification capability. The EMG signals from 8 hip muscles of 13 healthy persons were recorded as they walked on the different terrains. The signals from the sound side of a transfemoral amputee were also recorded. The features of these signals were obtained using data processing techniques with an identification process developed for the identification of the terrain type. The procedure was simplified by using only the signals from three muscles. The identification process worked well in an intelligent prosthetic knee in a laboratory setting.

  10. Prosthetic Engineering

    Science.gov (United States)

    ... Overview CoE for Limb Loss Prevention and Prosthetic Engineering Menu Menu VA Center of Excellence for Limb ... ZIP code here Enter ZIP code here Prosthetic Engineering - Overview Our aim is to improve prosthetic prescription ...

  11. Collagen tissue treated with chitosan solutions in carbonic acid for improved biological prosthetic heart valves.

    Science.gov (United States)

    Gallyamov, Marat O; Chaschin, Ivan S; Khokhlova, Marina A; Grigorev, Timofey E; Bakuleva, Natalia P; Lyutova, Irina G; Kondratenko, Janna E; Badun, Gennadii A; Chernysheva, Maria G; Khokhlov, Alexei R

    2014-04-01

    Calcification of bovine pericardium dramatically shortens typical lifetimes of biological prosthetic heart valves and thus precludes their choice for younger patients. The aim of the present work is to demonstrate that the calcification is to be mitigated by means of treatment of bovine pericardium in solutions of chitosan in carbonic acid, i.e. water saturated with carbon dioxide at high pressure. This acidic aqueous fluid unusually combines antimicrobial properties with absolute biocompatibility as far as at normal pressure it decomposes spontaneously and completely into H2O and CO2. Yet, at high pressures it can protonate and dissolve chitosan materials with different degrees of acetylation (in the range of 16-33%, at least) without any further pretreatment. Even exposure of the bovine pericardium in pure carbonic acid solution without chitosan already favours certain reduction in calcification, somewhat improved mechanical properties, complete biocompatibility and evident antimicrobial activity of the treated collagen tissue. The reason may be due to high extraction ability of this peculiar compressed fluidic mixture. Moreover, exposure of the bovine pericardium in solutions of chitosan in carbonic acid introduces even better mechanical properties and highly pronounced antimicrobial activity of the modified collagen tissue against adherence and biofilm formation of relevant Gram-positive and Gram-negative strains. Yet, the most important achievement is the detected dramatic reduction in calcification for such modified collagen tissues in spite of the fact that the amount of the thus introduced chitosan is rather small (typically ca. 1wt.%), which has been reliably detected using original tritium labelling method. We believe that these improved properties are achieved due to particularly deep and uniform impregnation of the collagen matrix with chitosan from its pressurised solutions in carbonic acid. PMID:24582232

  12. Face recognition in simulated prosthetic vision: face detection-based image processing strategies

    Science.gov (United States)

    Wang, Jing; Wu, Xiaobei; Lu, Yanyu; Wu, Hao; Kan, Han; Chai, Xinyu

    2014-08-01

    Objective. Given the limited visual percepts elicited by current prosthetic devices, it is essential to optimize image content in order to assist implant wearers to achieve better performance of visual tasks. This study focuses on recognition of familiar faces using simulated prosthetic vision. Approach. Combined with region-of-interest (ROI) magnification, three face extraction strategies based on a face detection technique were used: the Viola-Jones face region, the statistical face region (SFR) and the matting face region. Main results. These strategies significantly enhanced recognition performance compared to directly lowering resolution (DLR) with Gaussian dots. The inclusion of certain external features, such as hairstyle, was beneficial for face recognition. Given the high recognition accuracy achieved and applicable processing speed, SFR-ROI was the preferred strategy. DLR processing resulted in significant face gender recognition differences (i.e. females were more easily recognized than males), but these differences were not apparent with other strategies. Significance. Face detection-based image processing strategies improved visual perception by highlighting useful information. Their use is advisable for face recognition when using low-resolution prosthetic vision. These results provide information for the continued design of image processing modules for use in visual prosthetics, thus maximizing the benefits for future prosthesis wearers.

  13. Dutch evidence-based guidelines for amputation and prosthetics of the lower extremity : Rehabilitation process and prosthetics. Part 2

    NARCIS (Netherlands)

    Geertzen, Jan; van der Linde, Harmen; Rosenbrand, Kitty; Conradi, Marcel; Deckers, Jos; Koning, Jan; Rietman, Hans S.; van der Schaaf, Dick; van der Ploeg, Rein; Schapendonk, Johannes; Schrier, Ernst; Duijzentkunst, Rob Smit; Spruit-van Eijk, Monica; Versteegen, Gerbrig; Voesten, Harrie

    2015-01-01

    Background: A structured, multidisciplinary approach in the rehabilitation process after amputation is needed that includes a greater focus on the involvement of both (para)medics and prosthetists. There is considerable variation in prosthetic prescription concerning the moment of initial prosthesis

  14. Collagen tissue treated with chitosan solutions in carbonic acid for improved biological prosthetic heart valves

    Energy Technology Data Exchange (ETDEWEB)

    Gallyamov, Marat O., E-mail: glm@spm.phys.msu.ru [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Chaschin, Ivan S. [Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Khokhlova, Marina A. [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Grigorev, Timofey E. [Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Bakuleva, Natalia P.; Lyutova, Irina G.; Kondratenko, Janna E. [Bakulev Scientific Center for Cardiovascular Surgery of the Russian Academy of Medical Sciences, Roublyevskoe Sh. 135, Moscow 121552 (Russian Federation); Badun, Gennadii A.; Chernysheva, Maria G. [Radiochemistry Division, Faculty of Chemistry, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Khokhlov, Alexei R. [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation)

    2014-04-01

    Calcification of bovine pericardium dramatically shortens typical lifetimes of biological prosthetic heart valves and thus precludes their choice for younger patients. The aim of the present work is to demonstrate that the calcification is to be mitigated by means of treatment of bovine pericardium in solutions of chitosan in carbonic acid, i.e. water saturated with carbon dioxide at high pressure. This acidic aqueous fluid unusually combines antimicrobial properties with absolute biocompatibility as far as at normal pressure it decomposes spontaneously and completely into H{sub 2}O and CO{sub 2}. Yet, at high pressures it can protonate and dissolve chitosan materials with different degrees of acetylation (in the range of 16–33%, at least) without any further pretreatment. Even exposure of the bovine pericardium in pure carbonic acid solution without chitosan already favours certain reduction in calcification, somewhat improved mechanical properties, complete biocompatibility and evident antimicrobial activity of the treated collagen tissue. The reason may be due to high extraction ability of this peculiar compressed fluidic mixture. Moreover, exposure of the bovine pericardium in solutions of chitosan in carbonic acid introduces even better mechanical properties and highly pronounced antimicrobial activity of the modified collagen tissue against adherence and biofilm formation of relevant Gram-positive and Gram-negative strains. Yet, the most important achievement is the detected dramatic reduction in calcification for such modified collagen tissues in spite of the fact that the amount of the thus introduced chitosan is rather small (typically ca. 1 wt.%), which has been reliably detected using original tritium labelling method. We believe that these improved properties are achieved due to particularly deep and uniform impregnation of the collagen matrix with chitosan from its pressurised solutions in carbonic acid. - Highlights: • Treatment of GA

  15. A Palladium-Based Alloy for Prosthetic Dentistry:Structure and Properties

    Institute of Scientific and Technical Information of China (English)

    STEPANOVA Galina; PARUNOV Vitaly; VASEKIN Vasily; KAREVA Maria; SINAGEJKINA Julia

    2012-01-01

    Abstract.Using the results of physical and chemical researches and mechanical tests of the Pd-Au-Cu-Sn system alloys,a new palladium-based alloy has been chosen and studied in detail.It has a higher plasticity and a lower hardness than the Palladent alloy,widely used in prosthetic dentistry:its hardness is lower than 300 MPa,and its specific elongation is 10%~14 %.At the same time,such important practical characteristics of the alloys as the strength of adhesion to ceramics and thermal expansion coefficient are almost similar.

  16. Simulated Prosthetic Vision: The Benefits of Computer-Based Object Recognition and Localization.

    Science.gov (United States)

    Macé, Marc J-M; Guivarch, Valérian; Denis, Grégoire; Jouffrais, Christophe

    2015-07-01

    Clinical trials with blind patients implanted with a visual neuroprosthesis showed that even the simplest tasks were difficult to perform with the limited vision restored with current implants. Simulated prosthetic vision (SPV) is a powerful tool to investigate the putative functions of the upcoming generations of visual neuroprostheses. Recent studies based on SPV showed that several generations of implants will be required before usable vision is restored. However, none of these studies relied on advanced image processing. High-level image processing could significantly reduce the amount of information required to perform visual tasks and help restore visuomotor behaviors, even with current low-resolution implants. In this study, we simulated a prosthetic vision device based on object localization in the scene. We evaluated the usability of this device for object recognition, localization, and reaching. We showed that a very low number of electrodes (e.g., nine) are sufficient to restore visually guided reaching movements with fair timing (10 s) and high accuracy. In addition, performance, both in terms of accuracy and speed, was comparable with 9 and 100 electrodes. Extraction of high level information (object recognition and localization) from video images could drastically enhance the usability of current visual neuroprosthesis. We suggest that this method-that is, localization of targets of interest in the scene-may restore various visuomotor behaviors. This method could prove functional on current low-resolution implants. The main limitation resides in the reliability of the vision algorithms, which are improving rapidly.

  17. Rehabilitation and Prosthetic Services

    Science.gov (United States)

    ... Therapy Mental Health Physical Medicine and Rehabilitation Services Physical Therapy Prosthetic and Sensory Aids Service Benefits Prosthetic and Sensory Aids Service General Information Prosthetic ...

  18. Principal components analysis based control of a multi-dof underactuated prosthetic hand

    Directory of Open Access Journals (Sweden)

    Magenes Giovanni

    2010-04-01

    Full Text Available Abstract Background Functionality, controllability and cosmetics are the key issues to be addressed in order to accomplish a successful functional substitution of the human hand by means of a prosthesis. Not only the prosthesis should duplicate the human hand in shape, functionality, sensorization, perception and sense of body-belonging, but it should also be controlled as the natural one, in the most intuitive and undemanding way. At present, prosthetic hands are controlled by means of non-invasive interfaces based on electromyography (EMG. Driving a multi degrees of freedom (DoF hand for achieving hand dexterity implies to selectively modulate many different EMG signals in order to make each joint move independently, and this could require significant cognitive effort to the user. Methods A Principal Components Analysis (PCA based algorithm is used to drive a 16 DoFs underactuated prosthetic hand prototype (called CyberHand with a two dimensional control input, in order to perform the three prehensile forms mostly used in Activities of Daily Living (ADLs. Such Principal Components set has been derived directly from the artificial hand by collecting its sensory data while performing 50 different grasps, and subsequently used for control. Results Trials have shown that two independent input signals can be successfully used to control the posture of a real robotic hand and that correct grasps (in terms of involved fingers, stability and posture may be achieved. Conclusions This work demonstrates the effectiveness of a bio-inspired system successfully conjugating the advantages of an underactuated, anthropomorphic hand with a PCA-based control strategy, and opens up promising possibilities for the development of an intuitively controllable hand prosthesis.

  19. Prosthetic Feet

    Science.gov (United States)

    ... age, weight, foot size, activity level, and job needs. Here are some facts to know: Basic Prosthetic Feet There are two types of basic ... knee from buckling add weight to the prosthesis, need periodic repair and cost a little more than most basic feet are often used by people who need ...

  20. Head mounted DMD based projection system for natural and prosthetic visual stimulation in freely moving rats

    Science.gov (United States)

    Arens-Arad, Tamar; Farah, Nairouz; Ben-Yaish, Shai; Zlotnik, Alex; Zalevsky, Zeev; Mandel, Yossi

    2016-01-01

    Novel technologies are constantly under development for vision restoration in blind patients. Many of these emerging technologies are based on the projection of high intensity light patterns at specific wavelengths, raising the need for the development of specialized projection systems. Here we present and characterize a novel projection system that meets the requirements for artificial retinal stimulation in rats and enables the recording of cortical responses. The system is based on a customized miniature Digital Mirror Device (DMD) for pattern projection, in both visible (525 nm) and NIR (915 nm) wavelengths, and a lens periscope for relaying the pattern directly onto the animal’s retina. Thorough system characterization and the investigation of the effect of various parameters on obtained image quality were performed using ZEMAX. Simulation results revealed that images with an MTF higher than 0.8 were obtained with little effect of the vertex distance. Increased image quality was obtained at an optimal pupil diameter and smaller field of view. Visual cortex activity data was recorded simultaneously with pattern projection, further highlighting the importance of the system for prosthetic vision studies. This novel head mounted projection system may prove to be a vital tool in studying natural and artificial vision in behaving animals. PMID:27731346

  1. Grasp and force based taxonomy of split-hook prosthetic terminal devices.

    Science.gov (United States)

    Belter, Joseph T; Reynolds, Bo C; Dollar, Aaron M

    2014-01-01

    In this paper, we analyze the use of the body-powered split-hook prosthetic terminal device, which is the most commonly used upper-limb prosthesis. We developed two taxonomies of split-hook use, one on grasp shape and one on force exertion, illustrating the functional capabilities and use cases of the device. Video captured from an amputee using a body-powered split-hook during a number of common activities was used to lend weight to the completeness of the classifications. These taxonomies serve to establish a common language and means of comparing the types of grasps achievable by simple terminal devices to those of advanced myoelectric terminal devices or even human hands. The first taxonomy categorizes the grasp type based on the contacts with the environment while the second is categorized by the method and limitation of force exertion. We discuss the difference between grasps capable of holding objects compared to those that are capable of acquiring objects and the importance of non-prehensile uses of the split-hook. The classification schemes lay the groundwork for further detailed study of split-hook use, and the discussion of the use cases described may help guide terminal device developers to create improved prostheses. PMID:25571512

  2. Is electroglottography-based videostroboscopic assessment of post-laryngectomy prosthetic speech useful?

    Directory of Open Access Journals (Sweden)

    Kazi Rehan

    2009-01-01

    Full Text Available Objectives: To use an electroglottography (EGG-based videostroboscopy tool to assess the anatomical and morphologic characteristics of the pharyngoesophageal (PE segment in tracheoesophageal (TO speakers. Study d0 esign: Cross-sectional cohort study. Subjects: Fifty-two post-laryngectomy patients with no recurrence and using prosthetic (Blom-Singer speech. Intervention: An electroglottography (EGG-based videostroboscopy tool EGG-based rigid videostroboscopy as well as perceptual evaluation. Outcome m0 easures: Stroboscopic protocol included nine subjective/visual parameters to evaluate the neoglottis and study correlation of the G (GRBAS scale and the overall voice quality (OVQ with the treatment variables. Results: Of the 52 laryngectomees, videostroboscopic recordings were possible in 46 patients (36 males and 10 females with a mean age of 63.4 ±10.5 (SD an electroglottography (EGG-based videostroboscopy tool years. All used the Blom-Singer valve and the median time since Total Laryngectomy was 2 years. The neoglottis was assessable in 26 patients. We were able to strobe only 9 patients. There was excellent correlation between G and OVQ (Spearman rho > 0.9. Statistically significant correlation was found between G1 and saliva (P = 0.03 and between good OVQ and saliva (P = 0.02; similarly, there was significant correlation between G1 and LVV (P = 0.05 and between good OVQ and LVV (P = 0.03. Conclusions: This study is the first to examine the use of an EGG-based stroboscopy instrument to evaluate TO speech. Our observations suggest that from the standpoint of functional voice, saliva and the LVV had statistically significant effect in determining voice quality.

  3. OCT-based profiler for automating ocular surface prosthetic fitting (Conference Presentation)

    Science.gov (United States)

    Mujat, Mircea; Patel, Ankit H.; Maguluri, Gopi N.; Iftimia, Nicusor V.; Patel, Chirag; Agranat, Josh; Tomashevskaya, Olga; Bonte, Eugene; Ferguson, R. Daniel

    2016-03-01

    The use of a Prosthetic Replacement of the Ocular Surface Environment (PROSE) device is a revolutionary treatment for military patients that have lost their eyelids due to 3rd degree facial burns and for civilians who suffer from a host of corneal diseases. However, custom manual fitting is often a protracted painful, inexact process that requires multiple fitting sessions. Training for new practitioners is a long process. Automated methods to measure the complete corneal and scleral topology would provide a valuable tool for both clinicians and PROSE device manufacturers and would help streamline the fitting process. PSI has developed an ocular anterior-segment profiler based on Optical Coherence Tomography (OCT), which provides a 3D measure of the surface of the sclera and cornea. This device will provide topography data that will be used to expedite and improve the fabrication process for PROSE devices. OCT has been used to image portions of the cornea and sclera and to measure surface topology for smaller contact lenses [1-3]. However, current state-of-the-art anterior eye OCT systems can only scan about 16 mm of the eye's anterior surface, which is not sufficient for covering the sclera around the cornea. In addition, there is no systematic method for scanning and aligning/stitching the full scleral/corneal surface and commercial segmentation software is not optimized for the PROSE application. Although preliminary, our results demonstrate the capability of PSI's approach to generate accurate surface plots over relatively large areas of the eye, which is not currently possible with any other existing platform. Testing the technology on human volunteers is currently underway at Boston Foundation for Sight.

  4. Prosthetic synovitis.

    Science.gov (United States)

    Eftekhar, N S; Doty, S B; Johnston, A D; Parisien, M V

    1985-01-01

    The term "prosthetic synovitis" is applied to reactive changes resulting from a synovial-like membrane formed between a failed prosthesis (noninfected) and the bone interface. This report is the result of light-microscopic and clinical examination of more than 100 specimens obtained at surgery of failed previous hip replacements. The morphology and cell distribution of those tissues removed at surgery in 51 noninfected cemented total hip operations allowed a quantitative estimate of surface cell population by a "touch imprint" technique; qualitative and quantitative estimate (scale, 1 to 4+) of cell population and foreign body materials by light microscopy; and electron microscopy and biochemical analysis of selected samples. Histologic examination included the following cell population, in decreasing order of frequency: acidophilic histiocytes (95%); giant cells (80%); fibronoid material (80%); lymphocyte and plasma cells (26%); and neutrophils (8%). Microscopic examination showed that the largest particles of acrylic cement and shards of high-density polyethylene appeared to be walled off by connective tissue capsules. The majority of smaller particles were incorporated into the histiocyte/macrophage or giant cell population. Histochemistry indicated that these particles elicited "foci" of cellular activity within the synovial-like membrane. This increased activity included the appearance of increased endogenous peroxidase activity in those macrophages within the "foci"; increased betagalactosidae activity among these histiocytes; and a localization of acid phosphates activity within giant cells along the borders of inclusions within the cell cytoplasm. We conclude that wear products resulting from total hip arthroplasty, including the bone cement, can induce increased lysosomal and proteolytic activity within the histiocyte and giant cell populations. It may be important to emphasize that there were "reactive foci" within the membrane and that the entire

  5. Application of self-report and performance-based outcome measures to determine functional differences between four categories of prosthetic feet

    Directory of Open Access Journals (Sweden)

    Robert S. Gailey, PhD, PT

    2012-06-01

    Full Text Available We examined the application of outcome measures to determine changes in function caused by standardized functional prosthetic gait training and the use of four different prosthetic feet in people with unilateral transtibial limb loss. Two self-report measures (Prosthetic Evaluation Questionnaire-Mobility Scale [PEQ-13] and Locomotor Capabilities Index [LCI], and three performance-based measures (Amputee Mobility Predictor with a prosthesis [AMPPRO], 6-minute walk test [6MWT] and step activity monitor [SAM] were used. Ten people with unilateral transtibial limb loss, five with peripheral vascular disease (PVD and five without PVD, completed testing. Subjects were tested at baseline and after receiving training with their existing prosthesis and with the study socket and four prosthetic feet, i.e., SACH (solid ankle cushion heel, SAFE (stationary attachment flexible endoskeletal, Talux, and Proprio feet, over 8 to 10 weeks. Training was administered between testing sessions. No differences were detected by the PEQ-13, LCI, 6MWT, or SAM following training and after fitting with test feet. The AMPPRO demonstrated differences following training with the existing prosthesis in the PVD group and between selected feet from baseline testing (p prosthetic feet.

  6. Prosthetic avian vocal organ controlled by a freely behaving bird based on a low dimensional model of the biomechanical periphery.

    Directory of Open Access Journals (Sweden)

    Ezequiel M Arneodo

    Full Text Available Because of the parallels found with human language production and acquisition, birdsong is an ideal animal model to study general mechanisms underlying complex, learned motor behavior. The rich and diverse vocalizations of songbirds emerge as a result of the interaction between a pattern generator in the brain and a highly nontrivial nonlinear periphery. Much of the complexity of this vocal behavior has been understood by studying the physics of the avian vocal organ, particularly the syrinx. A mathematical model describing the complex periphery as a nonlinear dynamical system leads to the conclusion that nontrivial behavior emerges even when the organ is commanded by simple motor instructions: smooth paths in a low dimensional parameter space. An analysis of the model provides insight into which parameters are responsible for generating a rich variety of diverse vocalizations, and what the physiological meaning of these parameters is. By recording the physiological motor instructions elicited by a spontaneously singing muted bird and computing the model on a Digital Signal Processor in real-time, we produce realistic synthetic vocalizations that replace the bird's own auditory feedback. In this way, we build a bio-prosthetic avian vocal organ driven by a freely behaving bird via its physiologically coded motor commands. Since it is based on a low-dimensional nonlinear mathematical model of the peripheral effector, the emulation of the motor behavior requires light computation, in such a way that our bio-prosthetic device can be implemented on a portable platform.

  7. Microprocessor prosthetic knees.

    Science.gov (United States)

    Berry, Dale

    2006-02-01

    This article traces the development of microprocessor prosthetic knees from early research in the 1970s to the present. Read about how microprocessor knees work, functional options, patient selection, and the future of this prosthetic.

  8. MEMS-based bubble pressure sensor for prosthetic socket interface pressure measurement.

    Science.gov (United States)

    Wheeler, Jason W; Dabling, Jeffrey G; Chinn, Douglas; Turner, Timothy; Filatov, Anton; Anderson, Larry; Rohrer, Brandon

    2011-01-01

    The ability to chronically monitor pressure at the prosthetic socket/residual limb interface could provide important data to the research and clinical communities. With this application in mind, we describe a novel type of sensor which consists of a MEMS pressure sensor and custom electronics packaged in a fluid-filled bubble. The sensor is characterized and compared to two commercially-available technologies. The bubble sensor has excellent drift performance and good sensing resolution. It exhibits hysteresis which may be due to the silicone that the sensor is molded in. To reduce hysteresis, it may be advisable to place the sensor between the liner and the socket rather molding directly into the liner.

  9. Design of Shape Memory Alloy-Based and Tendon-Driven Actuated Fingers Towards a Hybrid Anthropomorphic Prosthetic Hand

    Directory of Open Access Journals (Sweden)

    Erkan Kaplanoglu

    2012-09-01

    Full Text Available This paper presents the design of tendon‐driven actuated fingers using a shape memory alloy for a hybrid anthropomorphic prosthetic hand. The ring and little (pinky fingers are selected for shape memory activation due to their lower degree of movement during multiple grasping configurations. The fingersʹ tendon system is based on shape memory alloy (SMA wires that form artificial muscle pairs for the required flexion/extension of the finger joints. The finger has four degrees of freedom such that three of them are active. An experimental setup was developed to evaluate the performance of the ring and little fingers. An electromyography (EMG controlled Pulse Width Modulated (PWM technique is preferred for the actuation of joint motions using a high speed microcontroller.

  10. Psycho-physiological assessment of a prosthetic hand sensory feedback system based on an auditory display: a preliminary study

    Directory of Open Access Journals (Sweden)

    Gonzalez Jose

    2012-06-01

    Full Text Available Abstract Background Prosthetic hand users have to rely extensively on visual feedback, which seems to lead to a high conscious burden for the users, in order to manipulate their prosthetic devices. Indirect methods (electro-cutaneous, vibrotactile, auditory cues have been used to convey information from the artificial limb to the amputee, but the usability and advantages of these feedback methods were explored mainly by looking at the performance results, not taking into account measurements of the user’s mental effort, attention, and emotions. The main objective of this study was to explore the feasibility of using psycho-physiological measurements to assess cognitive effort when manipulating a robot hand with and without the usage of a sensory substitution system based on auditory feedback, and how these psycho-physiological recordings relate to temporal and grasping performance in a static setting. Methods 10 male subjects (26+/-years old, participated in this study and were asked to come for 2 consecutive days. On the first day the experiment objective, tasks, and experiment setting was explained. Then, they completed a 30 minutes guided training. On the second day each subject was tested in 3 different modalities: Auditory Feedback only control (AF, Visual Feedback only control (VF, and Audiovisual Feedback control (AVF. For each modality they were asked to perform 10 trials. At the end of each test, the subject had to answer the NASA TLX questionnaire. Also, during the test the subject’s EEG, ECG, electro-dermal activity (EDA, and respiration rate were measured. Results The results show that a higher mental effort is needed when the subjects rely only on their vision, and that this effort seems to be reduced when auditory feedback is added to the human-machine interaction (multimodal feedback. Furthermore, better temporal performance and better grasping performance was obtained in the audiovisual modality. Conclusions The performance

  11. Design and development of a prosthetic implant for cardiovascular reconstructions

    OpenAIRE

    Ahmed, M.

    2011-01-01

    There is a significant worldwide demand for a small calibre vascular graft for use as a bypass or replacement conduit. Our lab has developed a novel nanocomposite poly- mer based on polyhedral oligomeric silsesquioxane and poly(carbonate-urea)urethane (POSS-PCU) which has displayed promising properties in vitro. In this thesis, POSS- PCU has been utilised to fabricate prosthetic small calibre conduits for use as arterial replacements. An important feature in determining the succes...

  12. Thermoplastics for prosthetic applications.

    Science.gov (United States)

    Lawrence, R B; Davies, R M

    1981-10-01

    The rapid and accurate thermoforming of plastics for prosthetic applications has been the subject of considerable research and development by the Bioengineering Centre. This paper outlines the progress in the general concepts that have been effected to date. The original below knee (B/K) socket vacuum forming technique has been extended to above knee (A/K) and supracondylar cases, and there have been developments in rotational casting technology. The work is necessarily based on a sound understanding of the properties of the materials concerned and of the associated manufacturing processes. The contribution of the Bioengineering Centre is outlined together with summaries of collaborative work carried out with other organizations.

  13. Gaitography applied to prosthetic walking.

    Science.gov (United States)

    Roerdink, Melvyn; Cutti, Andrea G; Summa, Aurora; Monari, Davide; Veronesi, Davide; van Ooijen, Mariëlle W; Beek, Peter J

    2014-11-01

    During walking on an instrumented treadmill with an embedded force platform or grid of pressure sensors, center-of-pressure (COP) trajectories exhibit a characteristic butterfly-like shape, reflecting the medio-lateral and anterior-posterior weight shifts associated with alternating steps. We define "gaitography" as the analysis of such COP trajectories during walking (the "gaitograms"). It is currently unknown, however, if gaitography can be employed to characterize pathological gait, such as lateralized gait impairments. We therefore registered gaitograms for a heterogeneous sample of persons with a trans-femoral and trans-tibial amputation during treadmill walking at a self-selected comfortable speed. We found that gaitograms directly visualize between-person differences in prosthetic gait in terms of step width and the relative duration of prosthetic and non-prosthetic single-support stance phases. We further demonstrated that one should not only focus on the gaitogram's shape but also on the time evolution along that shape, given that the COP evolves much slower in the single-support phase than in the double-support phase. Finally, commonly used temporal and spatial prosthetic gait characteristics were derived, revealing both individual and systematic differences in prosthetic and non-prosthetic step lengths, step times, swing times, and double-support durations. Because gaitograms can be rapidly collected in an unobtrusive and markerless manner over multiple gait cycles without constraining foot placement, clinical application of gaitography seems both expedient and appealing. Studies examining the repeatability of gaitograms and evaluating gaitography-based gait characteristics against a gold standard with known validity and reliability are required before gaitography can be clinically applied.

  14. Prevention of Prosthetic Dentistry

    Directory of Open Access Journals (Sweden)

    Eremin O.V.

    2011-03-01

    Full Text Available Prevention in prosthetic dentistry is not just a regular oral hygiene and the prevention of caries in the early stages of its development. The initial goal of orthopedic and dental should be the ability to convey to the patient's sense of pros-thetics that proteziruya one saved more. An example is included prosthetic dental arch defects with bridges or single artificial crowns on implants that will prevent movement of teeth and the continuity of the dentition

  15. A novel four-bar linkage prosthetic knee based on magnetorheological effect: principle, structure, simulation and control

    Science.gov (United States)

    Xu, Lei; Wang, Dai-Hua; Fu, Qiang; Yuan, Gang; Hu, Lei-Zi

    2016-11-01

    In this paper, the principle and structure of the four-bar linkage prosthetic knee based on the magnetorheological effect (FLPKME) are proposed and realized by individually integrating the upper and lower link rods of the four-bar linkage with the piston rod and the outer cylinder of the magnetorheological (MR) damper. The integrated MR damper, in which the MR fluid is operated in the shear mode, has a double-ended structure. The prototype of the FLPKME is designed and fabricated. Utilizing the developed FLPKME, the lower limb prosthesis is developed, modeled, and simulated. On these bases, the control algorithm for the FLPKME is developed. A test platform for the FLPKME is developed and the performance of the FLPKME with seven constant currents and controlled currents by the control algorithm developed in this paper are experimentally tested. The results show that the FLPKME with a constant current of 1.6 A possesses the basic stable gait, and the FLPKME with the controlled currents by the control algorithm developed in this paper is able to track the motions well and to imitate the natural motions of a healthy human knee joint.

  16. GIANT PROSTHETIC VALVE THROMBUS

    Directory of Open Access Journals (Sweden)

    Prashanth Kumar

    2015-04-01

    Full Text Available Mechanical prosthetic valves are predisposed to bleeding, thrombosis & thromboembolic complications. Overall incidence of thromboembolic complications is 1% per year who are on oral anticoagulants, whereas bleeding complications incidence is 0.5% to 6.6% per year. 1, 2 Minimization of Scylla of thromboembolic & Charybdis of bleeding complication needs a balancing act of optimal antithrombotic therapy. We are reporting a case of middle aged male patient with prosthetic mitral valve presenting in heart failure. Patient had discontinued anticoagulants, as he had subdural hematoma in the past. He presented to our institute with a giant prosthetic valve thrombus.

  17. Prosthetics and Related Technology

    Science.gov (United States)

    ... forms of retinal blindness. Source: Boston Retinal Implant Project, funded in part by VA. VA Prosthetics Research ... their injuries. For questions or additional copies contact: R&D Communications (12) 103 South Gay Street, Ste. 517 ...

  18. Imprecise knowledge based design and development of titanium alloys for prosthetic applications.

    Science.gov (United States)

    Datta, S; Mahfouf, M; Zhang, Q; Chattopadhyay, P P; Sultana, N

    2016-01-01

    Imprecise knowledge on the composition-processing-microstructure-property correlation of titanium alloys combined with experimental data are used for developing rule based models for predicting the strength and elastic modulus of titanium alloys. The developed models are used for designing alloys suitable for orthopedic and dental applications. Reduced Space Searching Algorithm is employed for the multi-objective optimization to find composition, processing and microstructure of titanium alloys suitable for orthopedic applications. The conflicting requirements attributes of the alloys for this particular purpose are high strength with low elastic modulus, along with adequate biocompatibility and low costs. The 'Pareto' solutions developed through multi-objective optimization show that the preferred compositions for the fulfilling the above objectives lead to β or near β-alloys. The concept of decision making employed on the solutions leads to some compositions, which should provide better combination of the required attributes. The experimental development of some of the alloys has been carried out as guided by the model-based design methodology presented in this research. Primary characterizations of the alloys show encouraging results in terms of the mechanical properties. PMID:26398780

  19. Imprecise knowledge based design and development of titanium alloys for prosthetic applications.

    Science.gov (United States)

    Datta, S; Mahfouf, M; Zhang, Q; Chattopadhyay, P P; Sultana, N

    2016-01-01

    Imprecise knowledge on the composition-processing-microstructure-property correlation of titanium alloys combined with experimental data are used for developing rule based models for predicting the strength and elastic modulus of titanium alloys. The developed models are used for designing alloys suitable for orthopedic and dental applications. Reduced Space Searching Algorithm is employed for the multi-objective optimization to find composition, processing and microstructure of titanium alloys suitable for orthopedic applications. The conflicting requirements attributes of the alloys for this particular purpose are high strength with low elastic modulus, along with adequate biocompatibility and low costs. The 'Pareto' solutions developed through multi-objective optimization show that the preferred compositions for the fulfilling the above objectives lead to β or near β-alloys. The concept of decision making employed on the solutions leads to some compositions, which should provide better combination of the required attributes. The experimental development of some of the alloys has been carried out as guided by the model-based design methodology presented in this research. Primary characterizations of the alloys show encouraging results in terms of the mechanical properties.

  20. Corti's organ physiology-based cochlear model: a microelectronic prosthetic implant

    Science.gov (United States)

    Rios, Francisco; Fernandez-Ramos, Raquel; Romero-Sanchez, Jorge; Martin, Jose Francisco

    2003-04-01

    Corti"s Organ is an Electro-Mechanical transducer that allows the energy coupling between acoustical stimuli and auditory nerve. Although the structure and funtionality of this organ are complex, state of the art models have been currently developed and tested. Cochlea model presented in this paper is based on the theories of Bekesy and others and concerns on the behaviour of auditory system on frequency-place domain and mechanisms of lateral inhibition. At the same time, present state of technology will permit us developing a microsystem that reproduce this phenomena applied to hearing aid prosthesis. Corti"s Organ is composed of more than 20.000 cilia excited by mean of travelling waves. These waves produce relative pressures distributed along the cochlea, exciting an specific number of cilia in a local way. Nonlinear mechanisms of local adaptation to the intensity (external cilia cells) and lateral inhibition (internal cilia cells) allow the selection of very few elements excited. These transmit a very precise intensity and frequency information. These signals are the only ones coupled to the auditory nerve. Distribution of pressure waves matches a quasilogaritmic law due to Cochlea morphology. Microsystem presented in this paper takes Bark"s law as an approximation to this behaviour consisting on grouped arbitrary elements composed of a set of selective coupled exciters (bank of filters according to Patterson"s model).These sets apply the intensity adaptation principles and lateral inhibition. Elements excited during the process generate a bioelectric signal in the same way than cilia cell. A microelectronic solution is presented for the development of an implantable prosthesis device.

  1. Tensile strength and impact resistance properties of materials used in prosthetic check sockets, copolymer sockets, and definitive laminated sockets

    Directory of Open Access Journals (Sweden)

    Maria J. Gerschutz, PhD

    2011-10-01

    Full Text Available Prosthetic sockets serve as the interface between people with amputations and their prostheses. Although most materials used to make prosthetic sockets have been used for many years, knowledge of these materials' properties is limited, especially after they are subjected to fabrication processes. This study evaluated tensile and impact properties of the current state-of-the-art materials used to fabricate prosthetic check sockets, copolymer sockets, and definitive laminated sockets. Thermolyn Rigid and Orfitrans Stiff check socket materials produced significantly lower tensile strength and impact resistance than polyethylene terephthalate glycol (PETG. Copolymer socket materials exhibited greater resistance to impact forces than the check socket materials but lower tensile strengths than PETG. The heated molding processes, for the check socket and copolymer materials, reduced both tensile strength and elongation at break. Definitive laminated sockets were sorted according to fabrication techniques. Nyglass material had significantly higher elongation, indicating a more ductile material than carbon-based laminations. Carbon sockets with pigmented resin had higher tensile strength and modulus at break than nonpigmented carbon sockets. Elongation at yield and elongation at break were similar for both types of carbon-based laminations. The material properties determined in this study provide a foundation for understanding and improving the quality of prosthetic sockets using current fabrication materials and a basis for evaluating future technologies.

  2. 基于FMG信号的假手比例控制系统研究%Research on Proportional Control System of Prosthetic Hand Based on FMG Signals

    Institute of Scientific and Technical Information of China (English)

    易金花; 喻洪流; 李盼盼; 赵胜楠

    2013-01-01

    The control of prosthetic hand is always a focus in prosthesis research. For solving current problems of controlling signals of skin surface electrical signals, we applied force myography (FMG) signals in prosthetic control of this system. The control system based on FMG signals were designed, containing signal acquisition and pre-processing, prosthetic control, motor driving and so on. Two-freedom artificial hand with proportional control was proposed through acquiring two-channel FMG signals from the amputee stump. The proportional control of prosthetic hand was achieved according to the average of FMG amplitude. The results showed that the control system had a great potential to control artificial hand and to realize speed adjustment effectively. Besides, the Virtual instrument software LabVIEW is adopted to establish the FMG signal collection and calibration of experiment system.%假手控制方法的研究一直是假肢研究技术的一个热点问题.针对现有皮肤表面电信号作为控制源的假手存在的问题,本系统采用前臂上肢肌肉膨胀收缩产生的压力信号作为控制信息源,设计了基于肌肉力(FMG)信号的假手控制系统,包括信号采集调理、微控制器控制、电机驱动等部分.通过采集残臂端两路FMG信号,提取信号的时域信息并采用阈值算法实现了手部2个自由5个动作.根据FMG信号均值的大小,改变假手驱动电路中PWM的占空比,从而实现电动假手速度的比例调节.实验结果表明本控制系统能够有效控制假手执行动作,实现速度的调节.另外,利用LabVIEW搭建了FMG信号采集标定平台,实现了FMG信号的实时数据采集和标定.

  3. Prosthetic prescription in the Netherlands : an interview with clinical experts

    NARCIS (Netherlands)

    Van Der Linde, H; Geertzen, JHB; Hofstad, CJ; Postema, K

    2004-01-01

    In the process of guideline development for prosthetic prescription in the Netherlands the authors made a study of the daily clinical practice of lower limb prosthetics. Besides the evidence-based knowledge from literature the more implicit knowledge from clinical experts is of importance for guidel

  4. Prosthetic prescription in the Netherlands: An interview with clinical experts

    NARCIS (Netherlands)

    Van Der Linde, H.; Geertzen, J.H.B.; Hofstad, C.J.; van Limbeek, Jonice; Postema, K.

    2004-01-01

    In the process of guideline development for prosthetic prescription in the Netherlands the authors made a study of the daily clinical practice of lower limb prosthetics. Besides the evidence-based knowledge from literature the more implicit knowledge from clinical experts is of importance for guidel

  5. The Prosthetic Experience Between Body and Technology

    DEFF Research Database (Denmark)

    Søndergaard, Morten

    2016-01-01

    In this paper, I argue that a prosthetic aesthetic instigated by experimental art practices operate with and within a ‘second nature’ – in-between science and art. Drawing on theories from Dewey and Edelman and examples from Da Vinci, Brancusi, Man Ray, Dali and Stelarc, I am calling for an exper......In this paper, I argue that a prosthetic aesthetic instigated by experimental art practices operate with and within a ‘second nature’ – in-between science and art. Drawing on theories from Dewey and Edelman and examples from Da Vinci, Brancusi, Man Ray, Dali and Stelarc, I am calling...... for an experience-based analysis of experimental practices operating between body and technology. These practices, which, rather than falling into the category of science fiction or horror cinema as some recent critique from post-human studies would have it, are pointing towards a genealogy of prosthetic experience...

  6. Welding of Prosthetic Alloys

    Directory of Open Access Journals (Sweden)

    Wojciechowska M.

    2015-04-01

    Full Text Available This paper presents the techniques of joining metal denture elements, used in prosthetic dentistry: the traditional soldering technique with a gas burner and a new technique of welding with a laser beam; the aim of the study was to make a comparative assessment of the quality of the joints in view of the possibility of applying them in prosthetic structures. Fractographic examinations were conducted along with tensile strength and impact strength tests, and the quality of the joints was assessed compared to the solid metal. The experiments have shown that the metal elements used to make dentures, joined by the technique which employs a laser beam, have better strength properties than those achieved with a gas burner.

  7. Magnets in prosthetic dentistry.

    Science.gov (United States)

    Riley, M A; Walmsley, A D; Harris, I R

    2001-08-01

    Magnetic retention is a popular method of attaching removable prostheses to either retained roots or osseointegrated implants. This review chronicles the development of magnets in dentistry and summarizes future research in their use. The literature was researched by using the Science Citation Index and Compendex Web from 1981 to 2000. Articles published before 1981 were hand researched from citations in other publications. Articles that discussed the use of magnets in relation to prosthetic dentistry were selected.

  8. A novel carbon fiber based porous carbon monolith

    Energy Technology Data Exchange (ETDEWEB)

    Burchell, T.D.; Klett, J.W.; Weaver, C.E.

    1995-06-01

    A novel porous carbon material based on carbon fibers has been developed. The material, when activated, develops a significant micro- or mesopore volume dependent upon the carbon fiber type utilized (isotropic pitch or polyacrylonitrile). The materials will find applications in the field of fluid separations or as a catalyst support. Here, the manufacture and characterization of our porous carbon monoliths are described. A novel adsorbent carbon composite material has been developed comprising carbon fibers and a binder. The material, called carbon fiber composite molecular sieve (CFCMS), was developed through a joint research program between Oak Ridge National Laboratory (ORNL) and the University of Kentucky, Center for Applied Energy Research (UKCAER).

  9. Gears Based on Carbon Nanotubes

    Science.gov (United States)

    Jaffe, Richard; Han, Jie; Globus, Al; Deardorff, Glenn

    2005-01-01

    Gears based on carbon nanotubes (see figure) have been proposed as components of an emerging generation of molecular- scale machines and sensors. In comparison with previously proposed nanogears based on diamondoid and fullerene molecules, the nanotube-based gears would have simpler structures and are more likely to be realizable by practical fabrication processes. The impetus for the practical development of carbon-nanotube- based gears arises, in part, from rapid recent progress in the fabrication of carbon nanotubes with prescribed diameters, lengths, chiralities, and numbers of concentric shells. The shafts of the proposed gears would be made from multiwalled carbon nanotubes. The gear teeth would be rigid molecules (typically, benzyne molecules), bonded to the nanotube shafts at atomically precise positions. For fabrication, it may be possible to position the molecular teeth by use of scanning tunneling microscopy (STM) or other related techniques. The capability to position individual organic molecules at room temperature by use of an STM tip has already been demonstrated. Routes to the chemical synthesis of carbon-nanotube-based gears are also under investigation. Chemical and physical aspects of the synthesis of molecular scale gears based on carbon nanotubes and related molecules, and dynamical properties of nanotube- based gears, have been investigated by computational simulations using established methods of quantum chemistry and molecular dynamics. Several particularly interesting and useful conclusions have been drawn from the dynamical simulations performed thus far: The forces acting on the gears would be more sensitive to local molecular motions than to gross mechanical motions of the overall gears. Although no breakage of teeth or of chemical bonds is expected at temperatures up to at least 3,000 K, the gears would not work well at temperatures above a critical range from about 600 to about 1,000 K. Gear temperature could probably be controlled by

  10. ORAL HYGIENE OF PROSTHETIC DENTURE USER IN KODINGARENG ISLAND

    OpenAIRE

    NUR, NURUL KUSUMADEWI S.KG

    2008-01-01

    Objectives:to determine the level of oral hygiene for prosthetic denture user, especially for full-denture in Kodingareng Island. This researchincluded the distribution level of prosthetic denture user based on age and education.Methods: the method that used in this research is observational descriptive withcross sectional-studyas the research design. Variable result of the research determined in to 3, those are bad, middle, and good. Result:the highest percentage o...

  11. Anticoagulation for Prosthetic Valves

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Kaneko

    2013-01-01

    Full Text Available Implantation of prosthetic valve requires consideration for anticoagulation. The current guideline recommends warfarin on all mechanical valves. Dabigatran is the new generation anticoagulation medication which is taken orally and does not require frequent monitoring. This drug is approved for treatment for atrial fibrillation and venous thromboembolism, but the latest large trial showed that this drug increases adverse events when used for mechanical valve anticoagulation. On-X valve is the new generation mechanical valve which is considered to require less anticoagulation due to its flow dynamics. The latest study showed that lower anticoagulation level lowers the incidence of bleeding, while the risk of thromboembolism and thrombosis remained the same. Anticoagulation poses dilemma in cases such as pregnancy and major bleeding event. During pregnancy, warfarin can be continued throughout pregnancy and switched to heparin derivative during 6–12 weeks and >36 weeks of gestation. Warfarin can be safely started after 1-2 weeks of discontinuation following major bleeding episode.

  12. Pursuing prosthetic electronic skin.

    Science.gov (United States)

    Chortos, Alex; Liu, Jia; Bao, Zhenan

    2016-09-01

    Skin plays an important role in mediating our interactions with the world. Recreating the properties of skin using electronic devices could have profound implications for prosthetics and medicine. The pursuit of artificial skin has inspired innovations in materials to imitate skin's unique characteristics, including mechanical durability and stretchability, biodegradability, and the ability to measure a diversity of complex sensations over large areas. New materials and fabrication strategies are being developed to make mechanically compliant and multifunctional skin-like electronics, and improve brain/machine interfaces that enable transmission of the skin's signals into the body. This Review will cover materials and devices designed for mimicking the skin's ability to sense and generate biomimetic signals. PMID:27376685

  13. Pursuing prosthetic electronic skin

    Science.gov (United States)

    Chortos, Alex; Liu, Jia; Bao, Zhenan

    2016-09-01

    Skin plays an important role in mediating our interactions with the world. Recreating the properties of skin using electronic devices could have profound implications for prosthetics and medicine. The pursuit of artificial skin has inspired innovations in materials to imitate skin's unique characteristics, including mechanical durability and stretchability, biodegradability, and the ability to measure a diversity of complex sensations over large areas. New materials and fabrication strategies are being developed to make mechanically compliant and multifunctional skin-like electronics, and improve brain/machine interfaces that enable transmission of the skin's signals into the body. This Review will cover materials and devices designed for mimicking the skin's ability to sense and generate biomimetic signals.

  14. Optimization-Based Design of a Small Pneumatic-Actuator-Driven Parallel Mechanism for a Shoulder Prosthetic Arm with Statics and Spatial Accessibility Evaluation

    Directory of Open Access Journals (Sweden)

    Masashi Sekine

    2013-07-01

    Full Text Available Human arms undertake most tasks in the activities of daily living (ADLs. When designing shoulder prostheses for high‐level upper‐limb amputees, we should consider not only how to realize high degrees of freedom under weight and shape constraints but also the user’s individual task space in daily life. An appropriate mechanical structure that can make full use of state‐of‐the‐art actuators and a scheme to optimize the structure’s configuration to match users’ spatial access and manipulability requirements are essential. In our previous research, a small pneumatic‐actuator‐driven parallel mechanism was studied as a shoulder prosthetic arm. In this paper, a systematic procedure is proposed to design the mechanism for a shoulder prosthesis considering force and spatial accessibility. This procedure includes ADL measurements to obtain the task spaces for individual subjects, indexes to evaluate the force and spatial accessibility and an optimization process based on kinematic and statics models. With this approach, the parallel mechanism was optimized for one important ADL task group, considering the trade‐off between its required force and working space. Moreover, it was confirmed that the proposed design procedure could find solutions for various spatial specifications. That is, the approach could be used for individualized shoulder prosthesis design.

  15. A prosthetic knee using magnetorhelogical fluid damper for above-knee amputees

    Science.gov (United States)

    Park, Jinhyuk; Choi, Seung-Bok

    2015-04-01

    A prosthetic knee for above-knee (AK) amputees is categorized into two types; namely a passive and an active type. The passive prosthetic knee is generally made by elastic materials such as carbon fiber reinforced composite material, titanium and etc. The passive prosthetic knee easy to walk. But, it has disadvantages such that a knee joint motion is not similar to ordinary people. On the other hand, the active prosthetic knee can control the knee joint angle effectively because of mechanical actuator and microprocessor. The actuator should generate large damping force to support the weight of human body. But, generating the large torque using small actuator is difficult. To solve this problem, a semi-active type prosthetic knee has been researched. This paper proposes a semi-active prosthetic knee using a flow mode magneto-rheological (MR) damper for AK amputees. The proposed semi-active type prosthetic knee consists of the flow mode MR damper, hinge and prosthetic knee body. In order to support weight of human body, the required energy of MR damper is smaller than actuator of active prosthetic leg. And it can control the knee joint angle by inducing the magnetic field during the stance phase.

  16. Prosthetic stomatitis with removable dentures

    Directory of Open Access Journals (Sweden)

    Rozalieva Yu.Yu.

    2012-06-01

    Full Text Available The Research Objective: To study patients with prosthetic stomatitis, who use the removable laminar dentures. Materials: The consultations and treatment of 79 patients aged 47-65 years have been conducted. The patients have been divided into two clinical groups. The first clinical group (39 persons with the performance of immediate prosthet-ics; the second control clinical group (40 persons — the permanent dentures were produced without the preliminary instruction. Results: All the patients, having the laminar dentures without the preliminary use of immediate constructions of dentures, in spite of repeated correction of them, have had changes of dentures and transitory fold. Patients have been exposed to prosthetic stomatitis of different etiology (without trauma; the single-shot or multiple correction of dentures by the method of rebasing with using of cold cure plastics has been made. Conclusion: Structural and functional changes of dentition during the prosthetic stomatitis lead to disorders, associated by the mucositis. Use of the term of «prosthetic stomatitis» reflects etiological and pathogenetic component of changes in the denture-supporting tissues

  17. Carbon dioxide conversion over carbon-based nanocatalysts.

    Science.gov (United States)

    Khavarian, Mehrnoush; Chai, Siang-Piao; Mohamed, Abdul Rahman

    2013-07-01

    The utilization of carbon dioxide for the production of valuable chemicals via catalysts is one of the efficient ways to mitigate the greenhouse gases in the atmosphere. It is known that the carbon dioxide conversion and product yields are still low even if the reaction is operated at high pressure and temperature. The carbon dioxide utilization and conversion provides many challenges in exploring new concepts and opportunities for development of unique catalysts for the purpose of activating the carbon dioxide molecules. In this paper, the role of carbon-based nanocatalysts in the hydrogenation of carbon dioxide and direct synthesis of dimethyl carbonate from carbon dioxide and methanol are reviewed. The current catalytic results obtained with different carbon-based nanocatalysts systems are presented and how these materials contribute to the carbon dioxide conversion is explained. In addition, different strategies and preparation methods of nanometallic catalysts on various carbon supports are described to optimize the dispersion of metal nanoparticles and catalytic activity. PMID:23901504

  18. [Prosthetic dental alloys. 1].

    Science.gov (United States)

    Quintero Engelmbright, M A

    1990-11-01

    A wide variety of restoration materials for prosthetic odontology is now available to the dental surgeon, either of the covalent type (acrylic resins), metallic (alloys), ionic (porcelains), or a combination of them, as in the so-called composites, such as the composite resins, or as ceramics-metals mixtures. An example of the latter is a product called Miracle-Mix, a glass ionomere cement reinforced with an amalgam alloy. In those cases where the blend is done by a synterization process, the material is called Cermet. The above-listed alternatives clearly evidence day-to-day advances in odontology, with researchers and manufacturers engaged the world over in improving existing products or developing new ones to enrich the dentist's armamentarium. As a side effect of this constant renewal, those dentists who have failed to update their knowledge fall behind in their practice as they persist in using products they have known for years, and may be deceived by advertisements of too-often unreliable products. It is, therefore, important to be aware of available products and their latest improvements. PMID:2132464

  19. [Prosthetic dental alloys (2)].

    Science.gov (United States)

    Quintero Englembright, M A

    1990-12-01

    A wide variety of restoration materials for prosthetic odontology is now available to the dental surgeon, either of the covalent type (acrylic resins), metallic (alloys), ionic (porcelains), or a combination of them, as in the so-called composites, such as the composite resins, or as ceramics-metals mixtures. An example of the latter is a product called Miracle-Mix, a glass ionomere cement reinforced with an amalgam alloy. In those cases where the blend is done by a synterization process, the material is called Cermet. The above-listed alternatives clearly evidence day-to-day advances in odontology, with researchers and manufacturers engaged the world over in improving existing products or developing new ones to enrich the dentist's armamentarium. As a side effect of this constant renewal, those dentists who have failed to update their knowledge fall behind in their practice as they persist in using products they have known for years, and may be deceived by advertisements of too-often unreliable products. It is, therefore, important to be aware of available products and their latest improvements. PMID:2132470

  20. New developments in prosthetic arm systems

    Directory of Open Access Journals (Sweden)

    Vujaklija I

    2016-07-01

    Full Text Available Ivan Vujaklija,1 Dario Farina,1 Oskar C Aszmann2 1Institute of Neurorehabilitation Systems, Bernstein Focus Neurotechnology Göttingen, University Medical Center Göttingen, Georg-August University, Göttingen, Germany; 2Christian Doppler Laboratory for Restoration of Extremity Function, Division of Plastic and Reconstructive Surgery, Department of Surgery, Medical University of Vienna, Vienna, Austria Abstract: Absence of an upper limb leads to severe impairments in everyday life, which can further influence the social and mental state. For these reasons, early developments in cosmetic and body-driven prostheses date some centuries ago, and they have been evolving ever since. Following the end of the Second World War, rapid developments in technology resulted in powered myoelectric hand prosthetics. In the years to come, these devices were common on the market, though they still suffered high user abandonment rates. The reasons for rejection were trifold – insufficient functionality of the hardware, fragile design, and cumbersome control. In the last decade, both academia and industry have reached major improvements concerning technical features of upper limb prosthetics and methods for their interfacing and control. Advanced robotic hands are offered by several vendors and research groups, with a variety of active and passive wrist options that can be articulated across several degrees of freedom. Nowadays, elbow joint designs include active solutions with different weight and power options. Control features are getting progressively more sophisticated, offering options for multiple sensor integration and multi-joint articulation. Latest developments in socket designs are capable of facilitating implantable and multiple surface electromyography sensors in both traditional and osseointegration-based systems. Novel surgical techniques in combination with modern, sophisticated hardware are enabling restoration of dexterous upper limb

  1. [Optogenetics and prosthetic treatment of retinal degeneration].

    Science.gov (United States)

    Kirpichnikov, M P; Ostrovskiy, M A

    2015-01-01

    This is a review of the current state of optogenetics-based research in the field of ophthalmology and physiology of vision. Optogenetics employs an interdisciplinary approach that amalgamates gene engineering, optics, and physiology. It involves exogenous expression of a light-activated protein in a very particular retinal cell enabling regulation (stimulation vs. inhibition) of its physiological activity. The experience with gene therapy came in very useful for optogenetics. However, unlike gene therapy, which is aimed at repairing damaged genes or replacing them with healthy ones, optogenetics is focused on protein genes delivery for further molecular control of the cell. In retina, the loss of photoreceptors is not necessarily followed by neuronal loss (at least ganglion cells remain intact), which determines the practicability of prosthetic treatment. Clinical trials can now be considered, owing to the first successful conversion of ganglion cells of mouse degenerative retinas into artificial photoreceptive cells with ON and OFF receptive fields, which is crucial for spatial vision. The following issues are reviewed here in detail: 1. Choice of cell targets within the degenerative retina. 2. Strategy of utilizing the existing light-sensitive agents and development of new optogenetic tools. 3. Gene delivery and expression in retinal cells. 4. Methods of evaluating the treatment success. 5. Selection criteria for optogenetic prosthetics. The conclusion discusses currently unsolved problems and prospects for optogenetic approaches to retinal prosthetics.

  2. 修复前正畸56例临床分析%Clinical analysis of orthodontic treatment before prosthetic treatment based on 56 cases

    Institute of Scientific and Technical Information of China (English)

    霍丽; 戴宁; 刘芳霞

    2011-01-01

    目的:分析修复前正畸的作用及特点.方法:对56例修复条件不佳的患者,先行正畸治疗创造修复条件,再行修复治疗,恢复牙列完整.结果:除1例放弃治疗外,55例患者修复条件得到改善,修复体在功能和美观方面都达到了满意的效果.结论:与常规正畸相比,修复前正畸有其自身的特点和规律.%Objective To analyze the effect and clinical features of the orthodontic treatment before prosthetic treatment. Methods 56 patients with poor oral conditions for prosthetic treatment were first applied to orthodontics treatment and then the missing teeth were fixed. Results In addition to 1 patient who abandoned treatment,55 patients' conditions for prosthetic treatment were improved through orthodontic treatment. Patients were satisfied with functions and aesthetics of the restoration. Conclusion The orthodontic treatment before prosthetic treatment has its own characteristics and regulations compared with conventional orthodontic treatment.

  3. Hybrid Composites Based on Carbon Fiber/Carbon Nanofilament Reinforcement

    Directory of Open Access Journals (Sweden)

    Mehran Tehrani

    2014-05-01

    Full Text Available Carbon nanofilament and nanotubes (CNTs have shown promise for enhancing the mechanical properties of fiber-reinforced composites (FRPs and imparting multi-functionalities to them. While direct mixing of carbon nanofilaments with the polymer matrix in FRPs has several drawbacks, a high volume of uniform nanofilaments can be directly grown on fiber surfaces prior to composite fabrication. This study demonstrates the ability to create carbon nanofilaments on the surface of carbon fibers employing a synthesis method, graphitic structures by design (GSD, in which carbon structures are grown from fuel mixtures using nickel particles as the catalyst. The synthesis technique is proven feasible to grow nanofilament structures—from ethylene mixtures at 550 °C—on commercial polyacrylonitrile (PAN-based carbon fibers. Raman spectroscopy and electron microscopy were employed to characterize the surface-grown carbon species. For comparison purposes, a catalytic chemical vapor deposition (CCVD technique was also utilized to grow multiwall CNTs (MWCNTs on carbon fiber yarns. The mechanical characterization showed that composites using the GSD-grown carbon nanofilaments outperform those using the CCVD-grown CNTs in terms of stiffness and tensile strength. The results suggest that further optimization of the GSD growth time, patterning and thermal shield coating of the carbon fibers is required to fully materialize the potential benefits of the GSD technique.

  4. Polymer-Based Carbon Monoxide Sensors

    Science.gov (United States)

    Homer, M. L.; Shevade, A. V.; Zhou, H.; Kisor, A. K.; Lara, L. M.; Yen, S.-P. S.; Ryan, M. A.

    2010-01-01

    Polymer-based sensors have been used primarily to detect volatile organics and inorganics; they are not usually used for smaller, gas phase molecules. We report the development and use of two types of polymer-based sensors for the detection of carbon monoxide. Further understanding of the experimental results is also obtained by performing molecular modeling studies to investigate the polymer-carbon monoxide interactions. The first type is a carbon-black-polymer composite that is comprised of a non-conducting polymer base that has been impregnated with carbon black to make it conducting. These chemiresistor sensors show good response to carbon monoxide but do not have a long lifetime. The second type of sensor has a non-conducting polymer base but includes both a porphyrin-functionalized polypyrrole and carbon black. These sensors show good, repeatable and reversible response to carbon monoxide at room temperature.

  5. Candida infection of a prosthetic shoulder joint

    International Nuclear Information System (INIS)

    A heroin addict developed a Candida parapsilosis infection in a prosthetic shoulder joint. Radiographs showed loose fragments of cement with prosthetic loosening. The patient was treated with removal of the prosthesis and intravenous amphotericin B followed by oral ketoconazole. (orig.)

  6. Successful thrombolysis for prosthetic pulmonary valve obstruction.

    OpenAIRE

    Lopez, J. A.; Strickman, N E; Jin, B S; X. G. Li; Phan, B; Zeluff, B J; Wilansky, S

    1995-01-01

    Thrombosis is a serious complication of prosthetic heart valve operations. In recent years, systemic thrombolysis has emerged as a suitable alternative to surgery. Experience with thrombosis of pulmonary prosthetic valves is very limited. We report a case of successful administration of intravenous streptokinase for thrombosis of a St. Jude Medical prosthetic valve 3 weeks after pulmonary valve replacement.

  7. Design of myoelectric controlled prosthetic hand system based on MSP430%基于MSP430的肌电假手系统设计

    Institute of Scientific and Technical Information of China (English)

    李天博; 陈玲; 陈坤华; 吕继东

    2012-01-01

    在对人体表面肌电信号研究的基础上,设计出一种肌电假手系统,其中包括肌电信号采集调理系统和假手控制系统.肌电信号经信号调理电路放大、滤波、陷波后,由低功耗的MSP430F149单片机进行A/D转换、特征计算.单片机结合肌电信号与触滑觉传感器反馈的信息来控制电机转向与转速,从而控制假手做出相应动作.通过实际采集的肌电信号在示波器上显示的波形与假手的动作进行对比,说明系统设计是合理有效的.%On the basis of research on surface electromyography ( sEMG) signal, a myoelectrical controlled prosthetic hand system is designed. It includes electromyography (EMG) signal acquiring and conditioning system and the prosthetic hand control system. Through the signal acquiring and conditioning circuit, the EMG signal is amplified,filtered and notched, A/D is converted and feature calculated by MSP430F149 microcontroller whose power consumption is low. The single-chip microcontroller combines the EMG signal with the feedback signal of the tactile and slip sensor,to control the velocity and the direction of the motor,so as to let the prosthetic hand to do corresponding action. The signal displayed on oscilloscope is compared with the action of prosthetic hand. The result shows that the design is reasonable and effective.

  8. Carbon-based Fuel Cell

    Energy Technology Data Exchange (ETDEWEB)

    Steven S. C. Chuang

    2005-08-31

    The direct use of coal in the solid oxide fuel cell to generate electricity is an innovative concept for power generation. The C-fuel cell (carbon-based fuel cell) could offer significant advantages: (1) minimization of NOx emissions due to its operating temperature range of 700-1000 C, (2) high overall efficiency because of the direct conversion of coal to CO{sub 2}, and (3) the production of a nearly pure CO{sub 2} exhaust stream for the direct CO{sub 2} sequestration. The objective of this project is to determine the technical feasibility of using a highly active anode catalyst in a solid oxide fuel for the direct electrochemical oxidation of coal to produce electricity. Results of this study showed that the electric power generation from Ohio No 5 coal (Lower Kittanning) Seam, Mahoning County, is higher than those of coal gas and pure methane on a solid oxide fuel cell assembly with a promoted metal anode catalyst at 950 C. Further study is needed to test the long term activity, selectivity, and stability of anode catalysts.

  9. [FTIR spectroscopic studies of facial prosthetic adhesives].

    Science.gov (United States)

    Kang, Biao; Yang, Qing-fang; Liang, Jian-feng; Zhao, Yi-min

    2008-10-01

    According to the composition of the traditional facial prosthetic adhesives, most of adhesives can be classified into two categories: acrylic polymer-based adhesive and silicone-based adhesive. In previous studies, measurements of various mechanical bond strengths were carried out, whereas the functional groups of the adhesives were evaluated seldom during the adhesion. In the present study the analysis of two facial prosthetic adhesives (Epithane and Secure Adhesive) was carried out by using infrared spectroscopy. Two adhesives in the form of fluid or semisolid were submitted to FTIR spectroscopy, respectively. The results showed that water and ammonia residue volatilized during the solidification of Epithane, and absorption peak reduction of carbonyl was due to the volatilization of acetate vinyl from Secure Adhesive. Similar silicone functional groups both in the silicone-based adhesive and in silicone elastomer could be the key to higher bond strength between silicone elastomer and skin with silicone-based adhesive. The position, shape of main absorption peaks of three adhesives didn't change, which showing that their main chemicals and basic structures didn't change during solidification. PMID:19123392

  10. Self-cleaning skin-like prosthetic polymer surfaces

    Science.gov (United States)

    Simpson, John T.; Ivanov, Ilia N.; Shibata, Jason

    2012-03-27

    An external covering and method of making an external covering for hiding the internal endoskeleton of a mechanical (e.g., prosthetic) device that exhibits skin-like qualities is provided. The external covering generally comprises an internal bulk layer in contact with the endoskeleton of the prosthetic device and an external skin layer disposed about the internal bulk layer. The external skin layer is comprised of a polymer composite with carbon nanotubes embedded therein. The outer surface of the skin layer has multiple cone-shaped projections that provide the external skin layer with superhydrophobicity. The carbon nanotubes are preferably vertically aligned between the inner surface and outer surface of the external skin layer in order to provide the skin layer with the ability to transmit heat. Superhydrophobic powders may optionally be used as part of the polymer composite or applied as a coating to the surface of the skin layer to enhance superhydrophobicity.

  11. Development of supercapacitors based on carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Block-type electrodes made of carbon nanotubes were fabricated by different processes. The volumetric specific capacitance based on such electrodes reached 107 F/cm3, which proves carbon nanotubes to be ideal candidate materials for supercapacitors. The composite electrodes consisting of carbon nanotubes and RuO2.xH2O were developed by the deposition of RuO2 on the surface of carbon nanotubes. Supercapacitors based on the composite electrodes show much higher specific capacitance than those based on pure carbon nanotube ones. A specific capacitance of 600 F/g can be achieved when the weight percent of RuO2.xH2O in the composite electrodes reaches 75%. In addition, supercapacitors based on the composite electrodes show both high energy density and high power density characteristics.

  12. Development of supercapacitors based on carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    马仁志; 魏秉庆; 徐才录; 梁吉; 吴德海

    2000-01-01

    Block-type electrodes made of carbon nanotubes were fabricated by different processes. The volumetric specific capacitance based on such electrodes reached 107 F/cm3, which proves carbon nanotubes to be ideal candidate materials for supercapacitors. The composite electrodes consisting of carbon nanotubes and RuO2 ·xH2O were developed by the deposition of RuO2 on the surface of carbon nanotubes. Supercapacitors based on the composite electrodes show much higher specific capacitance than those based on pure carbon nanotube ones. A specific capacitance of 600 F/g can be achieved when the weight percent of RuO2· xH2O in the composite electrodes reaches 75% . In addition , supercapacitors based on the composite electrodes show both high energy density and high power density characteristics.

  13. Preparation of microporous activated carbons based on carbonized apricot shells

    Directory of Open Access Journals (Sweden)

    Vladimir Pavlenko

    2014-10-01

    Full Text Available Results of applying the method of thermo-oxidative modification of fiber, based on the shell of apricot along with producing on its base microporous activated carbons that have high specific surface area and a significant amount of micropores were presented. The paper contains analysis and interpretation data of changes in the structure and composition of samples, which occurring as a result of thermal degradation of lignocellulosic materials. Morphological features of the surface of produced activated carbons were studied by using SEM microscopy; the pore structure and specific surface area were investigated using the method of low-temperature nitrogen adsorption.

  14. A computational method for comparing the behavior and possible failure of prosthetic implants

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, C.; Hollerbach, K.; Perfect, S.; Underhill, K.

    1995-05-01

    Prosthetic joint implants currently in use exhibit high Realistic computer modeling of prosthetic implants provides an opportunity for orthopedic biomechanics researchers and physicians to understand possible in vivo failure modes, without having to resort to lengthy and costly clinical trials. The research presented here is part of a larger effort to develop realistic models of implanted joint prostheses. The example used here is the thumb carpo-metacarpal (cmc) joint. The work, however, can be applied to any other human joints for which prosthetic implants have been designed. Preliminary results of prosthetic joint loading, without surrounding human tissue (i.e., simulating conditions under which the prosthetic joint has not yet been implanted into the human joint), are presented, based on a three-dimensional, nonlinear finite element analysis of three different joint implant designs.

  15. Antimicrobial Activity of Carbon-Based Nanoparticles

    Directory of Open Access Journals (Sweden)

    Solmaz Maleki Dizaj

    2015-03-01

    Full Text Available Due to the vast and inappropriate use of the antibiotics, microorganisms have begun to develop resistance to the commonly used antimicrobial agents. So therefore, development of the new and effective antimicrobial agents seems to be necessary. According to some recent reports, carbon-based nanomaterials such as fullerenes, carbon nanotubes (CNTs (especially single-walled carbon nanotubes (SWCNTs and graphene oxide (GO nanoparticles show potent antimicrobial properties. In present review, we have briefly summarized the antimicrobial activity of carbon-based nanoparticles together with their mechanism of action. Reviewed literature show that the size of carbon nanoparticles plays an important role in the inactivation of the microorganisms. As major mechanism, direct contact of microorganisms with carbon nanostructures seriously affects their cellular membrane integrity, metabolic processes and morphology. The antimicrobial activity of carbon-based nanostructures may interestingly be investigated in the near future owing to their high surface/volume ratio, large inner volume and other unique chemical and physical properties. In addition, application of functionalized carbon nanomaterials as carriers for the ordinary antibiotics possibly will decrease the associated resistance, enhance their bioavailability and provide their targeted delivery.

  16. Preparation of microporous activated carbons based on carbonized apricot shells

    OpenAIRE

    Vladimir Pavlenko; Sergey Anurov; Zulkhair Mansurov; Bijsenbaev Makhmut; Tatyana Konkova; Seithan Azat; Sandugash Tanirbergenova; Nurzhamal Zhylybaeva

    2014-01-01

    Results of applying the method of thermo-oxidative modification of fiber, based on the shell of apricot along with producing on its base microporous activated carbons that have high specific surface area and a significant amount of micropores were presented. The paper contains analysis and interpretation data of changes in the structure and composition of samples, which occurring as a result of thermal degradation of lignocellulosic materials. Morphological features of the surface of produced...

  17. Carbon Nanotube Paper-Based Electroanalytical Devices

    OpenAIRE

    Youngmi Koo; Vesselin N. Shanov; Yeoheung Yun

    2016-01-01

    Here, we report on carbon nanotube paper-based electroanalytical devices. A highly aligned-carbon nanotube (HA-CNT) array, grown using chemical vapor deposition (CVD), was processed to form bi-layered paper with an integrated cellulose-based Origami-chip as the electroanalytical device. We used an inverse-ordered fabrication method from a thick carbon nanotube (CNT) sheet to a thin CNT sheet. A 200-layered HA-CNT sheet and a 100-layered HA-CNT sheet are explored as a working electrode. The de...

  18. Validation of the prosthetic esthetic index

    DEFF Research Database (Denmark)

    Özhayat, Esben B; Dannemand, Katrine

    2014-01-01

    OBJECTIVES: In order to diagnose impaired esthetics and evaluate treatments for these, it is crucial to evaluate all aspects of oral and prosthetic esthetics. No professionally administered index currently exists that sufficiently encompasses comprehensive prosthetic esthetics. This study aimed...... to validate a new comprehensive index, the Prosthetic Esthetic Index (PEI), for professional evaluation of esthetics in prosthodontic patients. MATERIAL AND METHODS: The content, criterion, and construct validity; the test-retest, inter-rater, and internal consistency reliability; and the sensitivity...

  19. Retinal Prosthetics, Optogenetics, and Chemical Photoswitches

    OpenAIRE

    Marc, Robert; Pfeiffer, Rebecca; Jones, Bryan

    2014-01-01

    Three technologies have emerged as therapies to restore light sensing to profoundly blind patients suffering from late-stage retinal degenerations: (1) retinal prosthetics, (2) optogenetics, and (3) chemical photoswitches. Prosthetics are the most mature and the only approach in clinical practice. Prosthetic implants require complex surgical intervention and provide only limited visual resolution but can potentially restore navigational ability to many blind patients. Optogenetics uses viral ...

  20. Glassy carbon based supercapacitor stacks

    Energy Technology Data Exchange (ETDEWEB)

    Baertsch, M.; Braun, A.; Koetz, R.; Haas, O. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Considerable effort is being made to develop electrochemical double layer capacitors (EDLC) that store relatively large quantities of electrical energy and possess at the same time a high power density. Our previous work has shown that glassy carbon is suitable as a material for capacitor electrodes concerning low resistance and high capacity requirements. We present the development of bipolar electrochemical glassy carbon capacitor stacks of up to 3 V. Bipolar stacks are an efficient way to meet the high voltage and high power density requirements for traction applications. Impedance and cyclic voltammogram measurements are reported here and show the frequency response of a 1, 2, and 3 V stack. (author) 3 figs., 1 ref..

  1. Characterization of electrospun lignin based carbon fibers

    International Nuclear Information System (INIS)

    The production of lignin fibers has been studied in order to replace the need for petroleum based precursors for carbon fiber production. In addition to its positive environmental effects, it also benefits the economics of the industries which cannot take advantage of carbon fiber properties because of their high price. A large amount of lignin is annually produced as the byproduct of paper and growing cellulosic ethanol industry. Therefore, finding high value applications for this low cost, highly available material is getting more attention. Lignin is a biopolymer making about 15 – 30 % of the plant cell walls and has a high carbon yield upon carbonization. However, its processing is challenging due to its low molecular weight and also variations based on its origin and the method of separation from cellulose. In this study, alkali solutions of organosolv lignin with less than 1 wt/v% of poly (ethylene oxide) and two types of lignin (hardwood and softwood) were electrospun followed by carbonization. Different heating programs for carbonization were tested. The carbonized fibers had a smooth surface with an average diameter of less than 5 µm and the diameter could be controlled by the carbonization process and lignin type. Scanning electron microscopy (SEM) was used to study morphology of the fibers before and after carbonization. Thermal conductivity of a sample with amorphous carbon was 2.31 W/m.K. The electrospun lignin carbon fibers potentially have a large range of application such as in energy storage devices and water or gas purification systems

  2. Characterization of electrospun lignin based carbon fibers

    Energy Technology Data Exchange (ETDEWEB)

    Poursorkhabi, Vida; Mohanty, Amar; Misra, Manjusri [School of Engineering, Thornbrough Building, University of Guelph, Guelph, N1G 2W1, Ontario (Canada); Bioproducts Discovery and Development Centre, Department of Plant Agriculture, Crop Science Building, University of Guelph, Guelph, N1G 2W1, Ontario (Canada)

    2015-05-22

    The production of lignin fibers has been studied in order to replace the need for petroleum based precursors for carbon fiber production. In addition to its positive environmental effects, it also benefits the economics of the industries which cannot take advantage of carbon fiber properties because of their high price. A large amount of lignin is annually produced as the byproduct of paper and growing cellulosic ethanol industry. Therefore, finding high value applications for this low cost, highly available material is getting more attention. Lignin is a biopolymer making about 15 – 30 % of the plant cell walls and has a high carbon yield upon carbonization. However, its processing is challenging due to its low molecular weight and also variations based on its origin and the method of separation from cellulose. In this study, alkali solutions of organosolv lignin with less than 1 wt/v% of poly (ethylene oxide) and two types of lignin (hardwood and softwood) were electrospun followed by carbonization. Different heating programs for carbonization were tested. The carbonized fibers had a smooth surface with an average diameter of less than 5 µm and the diameter could be controlled by the carbonization process and lignin type. Scanning electron microscopy (SEM) was used to study morphology of the fibers before and after carbonization. Thermal conductivity of a sample with amorphous carbon was 2.31 W/m.K. The electrospun lignin carbon fibers potentially have a large range of application such as in energy storage devices and water or gas purification systems.

  3. Photonics based on carbon nanotubes

    OpenAIRE

    Gu, Qingyuan; Gicquel-Guézo, Maud; Loualiche, Slimane; Pouliquen, Julie Le; Batte, Thomas; Folliot, Hervé; Dehaese, Olivier; Grillot, Frederic; Battie, Yann; Loiseau, Annick; Liang, Baolai; Huffaker, Diana

    2013-01-01

    Among direct-bandgap semiconducting nanomaterials, single-walled carbon nanotubes (SWCNT) exhibit strong quasi-one-dimensional excitonic optical properties, which confer them a great potential for their integration in future photonics devices as an alternative solution to conventional inorganic semiconductors. In this paper, we will highlight SWCNT optical properties for passive as well as active applications in future optical networking. For passive applications, we directly compare the effi...

  4. Outcome-based Carbon Sequestration Resource Assessment

    Science.gov (United States)

    Sundquist, E. T.; Jain, A. K.

    2015-12-01

    Opportunities for carbon sequestration are an important consideration in developing policies to manage the mass balance of atmospheric carbon dioxide (CO2). Assessments of potential carbon sequestration, like other resource assessments, should be widely accepted within the scientific community and broadly applicable to public needs over a range of spatial and temporal scales. The essential public concern regarding all forms of carbon sequestration is their effectiveness in offsetting CO2 emissions. But the diverse forms and mechanisms of potential sequestration are reflected in diverse assessment methodologies that are very difficult for decision-makers to compare and apply to comprehensive carbon management. For example, assessments of potential geologic sequestration are focused on total capacities derived from probabilistic analyses of rock strata, while assessments of potential biologic sequestration are focused on annual rates calculated using biogeochemical models. Non-specialists cannot readily compare and apply such dissimilar estimates of carbon storage. To address these problems, assessment methodologies should not only tabulate rates and capacities of carbon storage, but also enable comparison of the time-dependent effects of various sequestration activities on the mitigation of increasing atmospheric CO2. This outcome-based approach requires consideration of the sustainability of the assessed carbon storage, as well as the response of carbon-cycle feedbacks. Global models can be used to compare atmospheric CO2 trajectories implied by alternative global sequestration strategies, but such simulations may not be accessible or useful in many decision settings. Simplified assessment metrics, such as ratios using impulse response functions, show some promise in providing comparisons of CO2 mitigation that are broadly useful while minimizing sensitivity to differences in global models and emissions scenarios. Continued improvements will require close

  5. 基于有限状态机控制的智能假肢踝关节*☆%Intelligent prosthetic ankle based on the finite state machine control

    Institute of Scientific and Technical Information of China (English)

    杨鹏; 柏健; 王欣然; 耿艳利

    2013-01-01

    BACKGROUND: At present, intel igent prosthesis only focuses on the function of knee joint, while ankle joint prosthesis is only used as the aid of prosthetic knee joint. So the normal gait cannot be realized according to the change of external environment and gait. OBJECTIVE: To develop a reliable intel igent prosthetic ankle in order to improve the gait of amputees effectively. METHODS: Based on the variable damping ankle-foot prosthesis, the control method of finite state machine was proposed. The ankle joint gait was planned in detail, and the relevant control strategy was developed. RESULTS AND CONCLUSION: Results indicate that the intel igent prosthetic ankle based on the finite state machine control can effectively fol ow health limb lateral movement, and can adapt to different paces, which lays an experimental basement for later knee ankle coordinated movement.%  背景:目前智能假肢只是考虑了膝关节的作用,假肢踝关节只是作为假肢膝关节的辅助工具,无法根据外部环境和步态的变化实现假肢自然的行走。目的:研制出可靠的智能假肢踝关节,有效改善截肢者的步态。方法:在阻尼可变式踝足假肢的基础上,提出了有限状态机的控制方法,对踝足步态进行了详细的划分,在每个步态内制定了相关的控制策略。结果与结论:实验结果表明,基于有限状态机控制的智能假肢踝关节能够有效的跟随健肢侧运动,能够适应不同的步速,为以后膝踝协调运动奠定了一定的实验基础。

  6. Novel Materials for Prosthetic Liners

    Science.gov (United States)

    Ragolta, Carolina I.; Morford, Megan

    2011-01-01

    Existing materials for prosthetic liners tend to be thick and airtight, causing perspiration to accumulate inside the liner and potentially causing infection and injury that reduce quality of life. The purpose of this project was to examine the suitability of aerogel for prosthetic liner applications. Three tests were performed on several types of aerogel to assess the properties of each material. Moisture vapor permeability was tested by incubating four aerogel varieties with an artificial sweat solution at 37.0 C and less than 20% relative humidity for 24 hours. Two aerogel varieties were eliminated from the study due to difficulties in handling the material, and further testing proceeded with Pyrogel in 2.0 and 6.0 mm thicknesses. Force distribution was tested by compressing samples under a load of 4448 N at a rate of 2.5 mm/min. Biofilm formation was tested in a high-shear CDC Biofilm Reactor. Results showed that 2.0 mm Pyrogel blanket allowed 55.7 plus or minus 28.7% of an artificial sweat solution to transpire, and 35.5 plus or minus 27.8% transpired through 6.0 mm Pyrogel blanket. Samples also outperformed the load-bearing capabilities of existing liner materials. No statistically significant difference was found between the two Pyrogel thicknesses for either moisture vapor permeability or force distribution. In addition, biofilm formation results showed no change between the two Pyrogel thicknesses. The breathability and load bearing properties of aerogel make it a suitable material for application to prosthetic liners.

  7. Brucella Endocarditis in Prosthetic Valves

    Science.gov (United States)

    Mehanic, Snjezana; Mulabdic, Velida; Baljic, Rusmir; Hadzovic-Cengic, Meliha; Pinjo, Fikret; Hadziosmanovic, Vesna; Topalovic, Jasna

    2012-01-01

    SUMMARY CONFLICT OF INTEREST: none declared. Introduction Brucella endocarditis (BE) is a rare but severe and potentially lethal manifestation of brucellosis. Pre-existing valves lesions and prosthetic valves (PV) are favorable for BE. Case report We represent the case of a 46-year-old man who was treated at the Clinic for Infectious Diseases, Clinical Center of Sarajevo University, as blood culture positive (Brucella melitensis) mitral and aortic PV endocarditis. He was treated with combined anti-brucella and cardiac therapy. Surgical intervention was postponed due to cardiac instability. Four months later he passed away. Surgery was not performed. PMID:24493988

  8. About aerogels based on carbon nanomaterials

    Directory of Open Access Journals (Sweden)

    Fail Sultanov

    2014-12-01

    Full Text Available In this review a current trends in development and application of carbon nanomaterials and derivatives based on them are presented. Aerogels based on graphene and other carbon nanomaterials present a class of novel ultralight materials in which a liquid phase is completely substituted by gaseous. In its turn graphene based aerogel was named as the lightest material, thus the record of aerographite, which has retained for a long time was beaten. Aerogels are characterized by low density, high surface area and high index of hydrophobicity. In addition, depending on its application, aerogels based on carbon nanomaterials can be electrically conductive and magnetic, while retaining the flexibility of its 3D structure. Impressive properties of novel material – aerogels causes a huge interest of scientists in order to find their application in various fields, ranging from environment problems to medicine and electronics.

  9. 基于先进制造平台的假肢接受腔计算机辅助制造系统%Computer-aided prosthetic socket manufacturing system based on an advanced manufacture technology

    Institute of Scientific and Technical Information of China (English)

    杨鹏; 陈玲玲; 李松; 宣伯凯

    2009-01-01

    OBJECTIVE:To overcome the shortcoming of manual method,computer-aided manufacturing (CAM) system of prosthetic socket is applied to improve socket's quality and processing efficiency,which also reduces the demand of operator's knowledge and experience.METHODS:Prosthetic socket CAM system was discussed based on an advanced manufacture technology,and the hardware and software were designed.The advanced manufacture platform was composed of an industrial personal computer (IPC),a motion control card,four sets of Panasonic digital AC servo control system,four lead screw guides,two spindle motor of milling cutter,a transducer,two switching power supply,limit switch and proximity switch.The software of prosthetic socket CAM system mainly included three function modules:parameter setting,machine testing and beginning processing.Through adjusting command pulse's input and driver's coefficient,the motor worked at different speeds.RESULTS:The result of experiment demonstrated that maximum rotational speed restriction was applied to protect the motor,and the motor could work very smoothly without vibration in very low speed.It was suitable for manufacture prosthetic sockets,and could manufacture the high quality prosthetic socket to satisfy the requirements of amputee.CONCLUSION:Prosthetic socket CAM system based on the advanced manufacture platform can overcome the shortcoming of traditional manual method,ensure product quality,and reduce the cost.The protracted experience of certified prosthetist was incorporated into the design program to reduce the demand of manipulator's knowledge and experience,increase the one-time success rate of manufacture prosthetic sockets,and improve the quality uncertainty of sockets.It can change the backward production mode of designing,measuring,taking model,and modifying model which depends on handwork.%目的:为了克服手工制作假肢接受腔的缺点,将计算机辅助制造技术用于加工假肢接受腔,提高接受腔的质量

  10. A carbon nanotube-based sensing element

    Institute of Scientific and Technical Information of China (English)

    YANG Xing; ZHOU Zhao-ying; WU Ying; ZHANG Jin; ZHANG Ying-ying

    2007-01-01

    A carbon nanotube-based(CNT) sensing element is presented, which consists of substrate, insulating layer, electrodes,carbon nanotube and measuring circuit. The sensing components are a single or array of CNTs, which are located on the two electrodes. The CNT-based sensing element is fabricated by CVD (chemical vapor deposition)-direct-growth on microelectrodes. The sensing model and measurement method of electromechanical property are also presented. Finally, the voltage-current characteristics are measured, which show that the CNT-based sensing element has good electrical properties.

  11. A Quality Function Deployment (QFD approach to designing a prosthetic myoelectric hand

    Directory of Open Access Journals (Sweden)

    Erika Sofía Olaya Escobar

    2010-04-01

    Full Text Available This paper presents a Quality Function Deployment (QFD model based on computing with words. It is specifically used in the House of Quality (HOQ construction phase. It illustrates the methodology employed in designing a prosthetic myoelectric hand.

  12. Parametric analysis using the finite element method to investigate prosthetic interface stresses for persons with trans-tibial amputation.

    Science.gov (United States)

    Silver-Thorn, M B; Childress, D S

    1996-07-01

    A finite element (FE) model of the below-knee residual limb and prosthetic socket was created to investigate the effects of parameter variations on the interface stress distribution during static stance. This model was based upon geometric approximations of anthropometric residual limb geometry. The model was not specific to an individual with amputation, but could be scaled to approximate the limb of a particular subject. Parametric analyses were conducted to investigate the effects of prosthetic socket design and residual limb geometry on the residual limb/prosthetic socket interface stresses. Behavioral trends were illustrated via sensitivity analysis. The results of the parametric analyses indicate that the residual limb/prosthetic socket interface stresses are affected by variations in both prosthetic design and residual limb geometry. Specifically, the analyses indicate: 1) the residual limb/prosthetic liner interface pressures are relatively insensitive to the socket stiffness; 2) the stiffness of the prosthetic liner influences the interface stress distribution for both the unrectified and patellar-tendon-bearing (PTB) rectified models-the external load state appears to influence the interface pressure distribution, while the prosthetic socket rectification appears to influence the interface shear stress distribution; 3) the interface pressures are very sensitive to the prosthetic rectification; 4) the shape and relative bulk of soft tissue may significantly influence the interface pressure distribution; 5) the interface pressure distribution is also influenced by the residual limb length; and 6) the stiffness/compliance of the residual limb soft tissues may significantly alter the interface pressure distribution.

  13. 基于特征映射的义齿表面三维变形设计方法%3D Deformation Design Method for Prosthetic Dental Surface Based on Feature Mapping

    Institute of Scientific and Technical Information of China (English)

    郑淑贤; 李佳; 孙庆丰

    2011-01-01

    The prosthetic tooth surface design is an important issue in dental computer aided design systems(CAD). The designed tooth shape should fit to the patient's tooth articulation environment and keep the topological features of the generic teeth. Aiming at the problem, a 3D deformation approach for prosthetic dental surface design based on feature mapping is presented. The main idea is by identifying the corresponding feature points between the preparation tooth and the standard tooth firstly, using a suitable radial basis function to define the feature mapping relations in both teeth, then through the corresponding features alignment and the surface interpolation deformation, the prosthetic tooth surface deformation is realized. The result of case study of the first molar in lower jaw shows that the design process is simple, the standard tooth surface deformation is reasonable, the surface distortion can be avoided and the final inlay surface matches well with the preparation tooth. The feature mapping design method provides a new way for clinic application in dental CAD.%义齿表面设计是牙科计算机辅助设计和制造系统的一个重要环节,设计的义齿形状必须符合患者的口腔咬合环境并能保持牙齿的拓扑结构特征.针对这一问题,在此提出一种基于特征映射的义齿表面三维变形设计方法.该方法主要思想是首先识别预备体与同名标准牙的重要特征点,采用径向基函数建立两者的特征映射关系,再通过对应特征点的位置对齐和表面的插值变形,实现义齿表面的变形设计.下颌第一磨牙嵌体的设计案例结果表明,该方法设计程序简单,标准牙曲面变形合理,能有效地避免曲面失真,最终生成的嵌体与预备体匹配良好,为牙科计算机辅助设计和制造系统的临床应用提供一种新的方法.

  14. A Miniature Force Sensor for Prosthetic Hands

    Science.gov (United States)

    Platt, Robert; Chu, Mars; Diftler, Myron; Martin, Toby; Valvo, Michael

    2006-01-01

    Tactile sensing is an important part of the development of new prosthetic hands. A number of approaches to establishing an afferent pathway back to the patient for tactile information are becoming available including tactors and direct stimulation of the afferent nerves. Tactile information can also be used by low-level control systems that perform simple tasks for the patient such as establishing a stable grasp and maintaining the grasping forces needed to hold an object. This abstract reports on the design of a small fingertip load cell based on semi-conductor strain gauges. Since this load cell is so small (measuring only 8.5mm in diameter and 6.25 mm in height), it easily fits into the tip of an anthropomorphic mechatronic hand. This load cell is tested by comparing a time series of force and moment data with reference data acquired from a much larger high-precision commercial load cell.

  15. Prosthetic

    Directory of Open Access Journals (Sweden)

    Pokpong Amornvit

    2014-01-01

    Full Text Available Ocular trauma can be caused by road traffic accidents, falls, assaults, or work-related accidents. Enucleation is often indicated after ocular injury or for the treatment of intraocular tumors, severe ocular infections, and painful blind eyes. Rehabilitation of an enucleated socket without an intraocular implant or with an inappropriately sized implant can result in superior sulcus deepening, enophthalmos, ptosis, ectropion, and lower lid laxity, which are collectively known as post-enucleation socket syndrome. This clinical report describes the rehabilitation of post-enucleation socket syndrome with a modified ocular prosthesis. Modifications to the ocular prosthesis were performed to correct the ptosis, superior sulcus deepening, and enophthalmos. The rehabilitation procedure produced satisfactory results.

  16. Amperometric biosensors based on carbon composite transducers

    Science.gov (United States)

    Lu, Fang

    1998-12-01

    Much current work in analytical chemistry is devoted to design of biosensors. One particular area in this field is the development of enzyme-based amperometric biosensors for the quantitative determination of a series of substrates in clinical, environmental, industrial and agricultural significance. This dissertation focuses on the design of improved amperometric biosensors based on carbon composite transducers. The use of metallized carbons as transducer materials results in remarkably selective amperometric biosensors. Such enzyme-based transducers eliminate major electroactive interferences, and hence circumvent the need for mediators or membrane barriers. The remarkable selectivity of metal-dispersed carbons is attributed to their strong, preferential, electrocatalytic capacity towards the reductive detection of biologically-generated hydrogen peroxide. Such electrocatalytic activity allows metal-dispersed biosensors to be operated at the optimal potential region between +0.1 and -0.2 V, where the unwanted reactions are neglected resulting in the lowest noise level. Several new materials (e.g., ruthenium on carbon, rhodium on carbon, etc.) and constructions (e.g., carbon fiber, electrochemical co-deposition transducer, etc.) were applied in the development of novel enzyme-based transducers in order to improve the selectivity and applicability of amperometric biosensors. The susceptibility of first-generation oxidase amperometric biosensing to oxygen fluctuations can be improved by using oxygen-rich fluorocarbons as the pasting binders in carbon paste enzyme transducers. Such binders provide an internal supply of oxygen resulting in efficient detection in oxygen-deficit conditions. In particular, the use of poly-chlorotrifluorethylene (Kel-F) oil as carbon paste binder results in a well-defined response and an identical signal up to 40 mM glucose in both the presence and absence of oxygen. Comparing with mediated or wired enzyme-based transducers, such internal

  17. Recent progress on carbon-based superconductors

    Science.gov (United States)

    Kubozono, Yoshihiro; Eguchi, Ritsuko; Goto, Hidenori; Hamao, Shino; Kambe, Takashi; Terao, Takahiro; Nishiyama, Saki; Zheng, Lu; Miao, Xiao; Okamoto, Hideki

    2016-08-01

    This article reviews new superconducting phases of carbon-based materials. During the past decade, new carbon-based superconductors have been extensively developed through the use of intercalation chemistry, electrostatic carrier doping, and surface-proving techniques. The superconducting transition temperature T c of these materials has been rapidly elevated, and the variety of superconductors has been increased. This review fully introduces graphite, graphene, and hydrocarbon superconductors and future perspectives of high-T c superconductors based on these materials, including present problems. Carbon-based superconductors show various types of interesting behavior, such as a positive pressure dependence of T c. At present, experimental information on superconductors is still insufficient, and theoretical treatment is also incomplete. In particular, experimental results are still lacking for graphene and hydrocarbon superconductors. Therefore, it is very important to review experimental results in detail and introduce theoretical approaches, for the sake of advances in condensed matter physics. Furthermore, the recent experimental results on hydrocarbon superconductors obtained by our group are also included in this article. Consequently, this review article may provide a hint to designing new carbon-based superconductors exhibiting higher T c and interesting physical features.

  18. Recent progress on carbon-based superconductors.

    Science.gov (United States)

    Kubozono, Yoshihiro; Eguchi, Ritsuko; Goto, Hidenori; Hamao, Shino; Kambe, Takashi; Terao, Takahiro; Nishiyama, Saki; Zheng, Lu; Miao, Xiao; Okamoto, Hideki

    2016-08-24

    This article reviews new superconducting phases of carbon-based materials. During the past decade, new carbon-based superconductors have been extensively developed through the use of intercalation chemistry, electrostatic carrier doping, and surface-proving techniques. The superconducting transition temperature T c of these materials has been rapidly elevated, and the variety of superconductors has been increased. This review fully introduces graphite, graphene, and hydrocarbon superconductors and future perspectives of high-T c superconductors based on these materials, including present problems. Carbon-based superconductors show various types of interesting behavior, such as a positive pressure dependence of T c. At present, experimental information on superconductors is still insufficient, and theoretical treatment is also incomplete. In particular, experimental results are still lacking for graphene and hydrocarbon superconductors. Therefore, it is very important to review experimental results in detail and introduce theoretical approaches, for the sake of advances in condensed matter physics. Furthermore, the recent experimental results on hydrocarbon superconductors obtained by our group are also included in this article. Consequently, this review article may provide a hint to designing new carbon-based superconductors exhibiting higher T c and interesting physical features. PMID:27351938

  19. Modelling Carbon Nanotubes-Based Mediatorless Biosensor

    Directory of Open Access Journals (Sweden)

    Julija Razumiene

    2012-07-01

    Full Text Available This paper presents a mathematical model of carbon nanotubes-based mediatorless biosensor. The developed model is based on nonlinear non-stationary reaction-diffusion equations. The model involves four layers (compartments: a layer of enzyme solution entrapped on a terylene membrane, a layer of the single walled carbon nanotubes deposited on a perforated membrane, and an outer diffusion layer. The biosensor response and sensitivity are investigated by changing the model parameters with a special emphasis on the mediatorless transfer of the electrons in the layer of the enzyme-loaded carbon nanotubes. The numerical simulation at transient and steady state conditions was carried out using the finite difference technique. The mathematical model and the numerical solution were validated by experimental data. The obtained agreement between the simulation results and the experimental data was admissible at different concentrations of the substrate.

  20. Modelling carbon nanotubes-based mediatorless biosensor.

    Science.gov (United States)

    Baronas, Romas; Kulys, Juozas; Petrauskas, Karolis; Razumiene, Julija

    2012-01-01

    This paper presents a mathematical model of carbon nanotubes-based mediatorless biosensor. The developed model is based on nonlinear non-stationary reaction-diffusion equations. The model involves four layers (compartments): a layer of enzyme solution entrapped on a terylene membrane, a layer of the single walled carbon nanotubes deposited on a perforated membrane, and an outer diffusion layer. The biosensor response and sensitivity are investigated by changing the model parameters with a special emphasis on the mediatorless transfer of the electrons in the layer of the enzyme-loaded carbon nanotubes. The numerical simulation at transient and steady state conditions was carried out using the finite difference technique. The mathematical model and the numerical solution were validated by experimental data. The obtained agreement between the simulation results and the experimental data was admissible at different concentrations of the substrate. PMID:23012537

  1. Effects of a flat prosthetic foot rocker section on balance and mobility

    OpenAIRE

    Andrew Hansen, PhD; Eric Nickel, MS; Joseph Medvec, CP; Steven Brielmaier, DPT; Alvin Pike, CP; Marilyn Weber, MD

    2014-01-01

    Previous studies have shown that the effective rocker shape of the physiologic ankle-foot system during standing and fore-aft swaying is much flatter than that used during walking, which indicates a more stable base of support for the standing/swaying activity. Previous work suggests that flat regions within the effective rocker shapes of prosthetic ankle-foot systems could provide enhanced stability for standing balance tasks. An experimental prosthetic foot was altered to provide three diff...

  2. Nanoscale Lasers Based on Carbon Peapods

    Institute of Scientific and Technical Information of China (English)

    HE Shao-Long; SHEN Jian-Qi

    2006-01-01

    A scheme of nanoscale lasers based on the so-called carbon peapods is examined in detail.Since there is considerable cylindrical empty space in the middle of a single-wall carbon nanotube (SWCNT),it can serve as a laser resonant cavity that consists of two highly reflecting alignment "mirrors" separated by a distance.These mirrors refer to ordered arrays of C60 inside SWCNTs,which have photonic bandgap structures.Meanwhile,ideally single-mode lasers are supposed to be produced in the nanoscale resonant cavity.

  3. Carbon Nanotube-Based Synthetic Gecko Tapes

    Science.gov (United States)

    Dhinojwala, Ali

    2008-03-01

    Wall-climbing geckos have unique ability to attach to different surfaces without the use of any viscoelastic glues. On coming in contact with any surface, the micron-size gecko foot-hairs deform, enabling molecular contact over large areas, thus translating weak van der Waals (vdW) interactions into enormous shear forces. We will present our recent results on the development of synthetic gecko tape using aligned carbon nanotubes to mimic the keratin hairs found on gecko feet. The patterned carbon nanotube-based gecko tape can support a shear stress (36 N/cm^2) nearly four times higher than the gecko foot and sticks to a variety of surfaces, including Teflon. Both the micron-size setae (replicated by nanotube bundles) and nanometer-size spatulas (individual nanotubes) are necessary to achieve macroscopic shear adhesion and to translate the weak vdW interactions into high shear forces. The carbon nanotube based tape offers an excellent synthetic option as a dry conductive reversible adhesive in microelectronics, robotics and space applications. The mechanism behind these large shear forces and self-cleaning properties of these carbon nanotube based synthetic gecko tapes will be discussed. This work was performed in collaboration with graduate students Liehui Ge, and Sunny Sethi, and collaborators from RPI; Lijie Ci and Professor Pulickel Ajayan.

  4. Development of an underactuated prosthetic hand with the step motor

    Institute of Scientific and Technical Information of China (English)

    Zhao Dawei; Jin Minghe; Jiang Li; Shi Shicai; Liu Hong

    2006-01-01

    We present the development of a novel prosthetic hand based on the underactuated mechanism. The aim is focused on increasing its dexterity while keeping the same dimension and weight of a traditional prosthetic device. The hybrid step motor is used as the actuator, which enables the finger to keep enough high contact torque on the grasped object with less energy consumption provided by the holding torque. The grasping force of the finger is estimated from the base joint torque, and the adoption of impedance control has provided compliance in the grasping. Also a parallel observer is used to switch over between the impedance control and the torque holding mode. The experimental results show the effectiveness of the design and control strategy.

  5. Carbon Market Regulation Mechanism Research Based on Carbon Accumulation Model with Jump Diffusion

    OpenAIRE

    Dongmei Guo; Yi Hu; Bingjie Zhang

    2014-01-01

    In order to explore carbon market regulation mechanism more effectively, based on carbon accumulation model with jump diffusion, this paper studies the carbon price from two perspectives of quantity instrument and price instrument and quantitatively simulates carbon price regulation mechanisms in the light of actual operation of EU carbon market. The results show that quantity instrument and price instrument both have certain effects on carbon market; according to the comparison of the elasti...

  6. DME Prosthetics Orthotics, and Supplies Fee Schedule

    Data.gov (United States)

    U.S. Department of Health & Human Services — Durable Medical Equipment, Prosthetics-Orthotics, and Supplies Fee Schedule. The list contains the fee schedule amounts, floors, and ceilings for all procedure...

  7. Advanced prosthetic techniques for below knee amputations.

    Science.gov (United States)

    Staats, T B

    1985-02-01

    Recent advances in the evaluation of the amputation stump, the materials that are available for prosthetic application, techniques of improving socket fit, and prosthetic finishings promise to dramatically improve amputee function. Precision casting techniques for providing optimal fit of the amputation stump using materials such as alginate are described. The advantages of transparent check sockets for fitting the complicated amputation stump are described. Advances in research that promise to provide more functional prosthetic feet and faster and more reliable socket molding are the use of CAD-CAM (computer aided design-computer aided manufacturing) and the use of gait analysis techniques to aid in the alignment of the prosthesis after socket fitting. Finishing techniques to provide a more natural appearing prosthesis are described. These advances will gradually spread to the entire prosthetic profession.

  8. Carbon Nanotube Paper-Based Electroanalytical Devices

    Directory of Open Access Journals (Sweden)

    Youngmi Koo

    2016-04-01

    Full Text Available Here, we report on carbon nanotube paper-based electroanalytical devices. A highly aligned-carbon nanotube (HA-CNT array, grown using chemical vapor deposition (CVD, was processed to form bi-layered paper with an integrated cellulose-based Origami-chip as the electroanalytical device. We used an inverse-ordered fabrication method from a thick carbon nanotube (CNT sheet to a thin CNT sheet. A 200-layered HA-CNT sheet and a 100-layered HA-CNT sheet are explored as a working electrode. The device was fabricated using the following methods: (1 cellulose-based paper was patterned using a wax printer, (2 electrical connection was made using a silver ink-based circuit printer, and (3 three electrodes were stacked on a 2D Origami cell. Electrochemical behavior was evaluated using electrochemical impedance spectroscopy (EIS and cyclic voltammetry (CV. We believe that this platform could attract a great deal of interest for use in various chemical and biomedical applications.

  9. Software tool for the prosthetic foot modeling and stiffness optimization.

    Science.gov (United States)

    Strbac, Matija; Popović, Dejan B

    2012-01-01

    We present the procedure for the optimization of the stiffness of the prosthetic foot. The procedure allows the selection of the elements of the foot and the materials used for the design. The procedure is based on the optimization where the cost function is the minimization of the difference between the knee joint torques of healthy walking and the walking with the transfemural prosthesis. We present a simulation environment that allows the user to interactively vary the foot geometry and track the changes in the knee torque that arise from these adjustments. The software allows the estimation of the optimal prosthetic foot elasticity and geometry. We show that altering model attributes such as the length of the elastic foot segment or its elasticity leads to significant changes in the estimated knee torque required for a given trajectory.

  10. Impact of advanced manufacturing technology on prosthetic and orthotic practice.

    Science.gov (United States)

    Jones, D

    1988-04-01

    Radical changes in the technology applied to prosthetics and orthotics are being proposed. This paper attempts to define the scope and character of advanced manufacturing technology and examines the rehabilitation problems which are or could be tackled. Lower-limb prosthetics has been the major area under investigation so far, but orthopaedic footwear, spinal orthotics and custom seating for the disabled have also been investigated using similar technological approaches. The whole process of patient measurement, device design, and component manufacture is conceived as an integrated system relying upon shape or tissue property sensing, computer based device design and computer-numerically-controlled or robot manufacturing processes. The aim is to retain flexibility for custom design which is necessary to provide for individual patients, and yet improve the rapidity and precision of overall device manufacture and service delivery.

  11. Software Tool for the Prosthetic Foot Modeling and Stiffness Optimization

    Directory of Open Access Journals (Sweden)

    Matija Štrbac

    2012-01-01

    Full Text Available We present the procedure for the optimization of the stiffness of the prosthetic foot. The procedure allows the selection of the elements of the foot and the materials used for the design. The procedure is based on the optimization where the cost function is the minimization of the difference between the knee joint torques of healthy walking and the walking with the transfemural prosthesis. We present a simulation environment that allows the user to interactively vary the foot geometry and track the changes in the knee torque that arise from these adjustments. The software allows the estimation of the optimal prosthetic foot elasticity and geometry. We show that altering model attributes such as the length of the elastic foot segment or its elasticity leads to significant changes in the estimated knee torque required for a given trajectory.

  12. Carbon-based tribofilms from lubricating oils.

    Science.gov (United States)

    Erdemir, Ali; Ramirez, Giovanni; Eryilmaz, Osman L; Narayanan, Badri; Liao, Yifeng; Kamath, Ganesh; Sankaranarayanan, Subramanian K R S

    2016-08-01

    Moving mechanical interfaces are commonly lubricated and separated by a combination of fluid films and solid 'tribofilms', which together ensure easy slippage and long wear life. The efficacy of the fluid film is governed by the viscosity of the base oil in the lubricant; the efficacy of the solid tribofilm, which is produced as a result of sliding contact between moving parts, relies upon the effectiveness of the lubricant's anti-wear additive (typically zinc dialkyldithiophosphate). Minimizing friction and wear continues to be a challenge, and recent efforts have focused on enhancing the anti-friction and anti-wear properties of lubricants by incorporating inorganic nanoparticles and ionic liquids. Here, we describe the in operando formation of carbon-based tribofilms via dissociative extraction from base-oil molecules on catalytically active, sliding nanometre-scale crystalline surfaces, enabling base oils to provide not only the fluid but also the solid tribofilm. We study nanocrystalline catalytic coatings composed of nitrides of either molybdenum or vanadium, containing either copper or nickel catalysts, respectively. Structurally, the resulting tribofilms are similar to diamond-like carbon. Ball-on-disk tests at contact pressures of 1.3 gigapascals reveal that these tribofilms nearly eliminate wear, and provide lower friction than tribofilms formed with zinc dialkyldithiophosphate. Reactive and ab initio molecular-dynamics simulations show that the catalytic action of the coatings facilitates dehydrogenation of linear olefins in the lubricating oil and random scission of their carbon-carbon backbones; the products recombine to nucleate and grow a compact, amorphous lubricating tribofilm. PMID:27488799

  13. Fermentation based carbon nanotube multifunctional bionic composites

    OpenAIRE

    Luca Valentini; Silvia Bittolo Bon; Stefano Signetti; Manoj Tripathi; Erica Iacob; Pugno, Nicola M.

    2016-01-01

    The exploitation of the processes used by microorganisms to digest nutrients for their growth can be a viable method for the formation of a wide range of so called biogenic materials that have unique properties that are not produced by abiotic processes. Here we produced living hybrid materials by giving to unicellular organisms the nutrient to grow. Based on bread fermentation, a bionic composite made of carbon nanotubes (CNTs) and a single-cell fungi, the Saccharomyces cerevisiae yeast extr...

  14. Fermentation based carbon nanotube bionic functional composites

    OpenAIRE

    Valentini, Luca; Bon, Silvia Bittolo; Signetti, Stefano; Tripathi, Manoj; Iacob, Erica; Pugno, Nicola M.

    2016-01-01

    The exploitation of the processes used by microorganisms to digest nutrients for their growth can be a viable method for the formation of a wide range of so called biogenic materials that have unique mechanical and physical properties that are not produced by abiotic processes. Based on grape must and bread fermentation, a bionic composite made of carbon nanotubes (CNTs) and single-cell fungi, the Saccharomyces cerevisiae yeast extract, was prepared by fermentation of such microorganisms at r...

  15. Quantum transport in carbon-based nanostructures

    OpenAIRE

    Nemec, Norbert

    2007-01-01

    The electronic structure and the quantum transport properties of graphene, carbon nanotubes and graphene nanoribbons are studied using analytical and numerical tools. Special care is taken in considering fundamental questions of high experimental relevance and in relating the results to experiments. The main focus of the work is on numerical calculations based on the tight-binding description of electrons, also integrating the results of microscopic ab initio calculations a...

  16. Carbon-based tribofilms from lubricating oils

    Science.gov (United States)

    Erdemir, Ali; Ramirez, Giovanni; Eryilmaz, Osman L.; Narayanan, Badri; Liao, Yifeng; Kamath, Ganesh; Sankaranarayanan, Subramanian K. R. S.

    2016-08-01

    Moving mechanical interfaces are commonly lubricated and separated by a combination of fluid films and solid ‘tribofilms’, which together ensure easy slippage and long wear life. The efficacy of the fluid film is governed by the viscosity of the base oil in the lubricant; the efficacy of the solid tribofilm, which is produced as a result of sliding contact between moving parts, relies upon the effectiveness of the lubricant’s anti-wear additive (typically zinc dialkyldithiophosphate). Minimizing friction and wear continues to be a challenge, and recent efforts have focused on enhancing the anti-friction and anti-wear properties of lubricants by incorporating inorganic nanoparticles and ionic liquids. Here, we describe the in operando formation of carbon-based tribofilms via dissociative extraction from base-oil molecules on catalytically active, sliding nanometre-scale crystalline surfaces, enabling base oils to provide not only the fluid but also the solid tribofilm. We study nanocrystalline catalytic coatings composed of nitrides of either molybdenum or vanadium, containing either copper or nickel catalysts, respectively. Structurally, the resulting tribofilms are similar to diamond-like carbon. Ball-on-disk tests at contact pressures of 1.3 gigapascals reveal that these tribofilms nearly eliminate wear, and provide lower friction than tribofilms formed with zinc dialkyldithiophosphate. Reactive and ab initio molecular-dynamics simulations show that the catalytic action of the coatings facilitates dehydrogenation of linear olefins in the lubricating oil and random scission of their carbon-carbon backbones; the products recombine to nucleate and grow a compact, amorphous lubricating tribofilm.

  17. Effects of a flat prosthetic foot rocker section on balance and mobility

    Directory of Open Access Journals (Sweden)

    Andrew Hansen, PhD

    2014-03-01

    Full Text Available Previous studies have shown that the effective rocker shape of the physiologic ankle-foot system during standing and fore-aft swaying is much flatter than that used during walking, which indicates a more stable base of support for the standing/swaying activity. Previous work suggests that flat regions within the effective rocker shapes of prosthetic ankle-foot systems could provide enhanced stability for standing balance tasks. An experimental prosthetic foot was altered to provide three different flat region lengths within its effective rocker shape. It was hypothesized that longer flat regions of the effective rocker shape would lead to improved standing balance outcomes and reduced walking performance for unilateral transtibial prosthesis users. However, no significant changes were seen in the balance and mobility outcomes of 12 unilateral transtibial prosthesis users when using the three prosthetic foot conditions. Subjects in the study significantly preferred prosthetic feet with relatively low to moderate flat regions over those with long flat regions. All the subjects without loss of light touch or vibratory sensation selected the prosthetic foot with the shortest flat region. More work is needed to investigate the effects of prosthetic foot properties on balance and mobility of prosthesis users.

  18. Analysis of maxillofacial prosthetics at university dental hospitals in the capital region of Korea

    Science.gov (United States)

    Lee, Jong-Ho

    2016-01-01

    PURPOSE The purpose of this study was to investigate the demographic patterns of maxillofacial prosthetic treatment to identify the characteristics and geographic distribution of patients with maxillofacial prosthetics in the capital region of Korea. MATERIALS AND METHODS This retrospective analytical multicenter study was performed by chart reviews. This study included patients who visited the department of prosthodontics at four university dental hospitals for maxillofacial prosthetic rehabilitation. Patients with facial and congenital defects or with insufficient medical data were excluded. The patients were classified into three categories based on the location of the defect. Patients' sex, age, and residential area were analyzed. Pearson's chi-square test with a significance level of 0.05 was used to analyze the variables. RESULTS Among 540 patients with maxillofacial prosthetics, there were 284 (52.59%) male patients and 256 (47.41%) female patients. The number of the patients varied greatly by hospital. Most patients were older than 70, and the most common defect was a hard palate defect. Chi-square analysis did not identify any significant differences in sex, age, and distance to hospital for any defect group (P>.05). CONCLUSION The results of this study indicated that there was imbalance in the distribution of patients with maxillofacial prosthetic among the hospitals in the capital region of Korea. Considerations on specialists and insurance policies for the improvement of maxillofacial prosthetics in Korea are required. PMID:27350859

  19. Polymeric photocatalysts based on graphitic carbon nitride.

    Science.gov (United States)

    Cao, Shaowen; Low, Jingxiang; Yu, Jiaguo; Jaroniec, Mietek

    2015-04-01

    Semiconductor-based photocatalysis is considered to be an attractive way for solving the worldwide energy shortage and environmental pollution issues. Since the pioneering work in 2009 on graphitic carbon nitride (g-C3N4) for visible-light photocatalytic water splitting, g-C3N4 -based photocatalysis has become a very hot research topic. This review summarizes the recent progress regarding the design and preparation of g-C3N4 -based photocatalysts, including the fabrication and nanostructure design of pristine g-C3N4 , bandgap engineering through atomic-level doping and molecular-level modification, and the preparation of g-C3N4 -based semiconductor composites. Also, the photo-catalytic applications of g-C3N4 -based photocatalysts in the fields of water splitting, CO2 reduction, pollutant degradation, organic syntheses, and bacterial disinfection are reviewed, with emphasis on photocatalysis promoted by carbon materials, non-noble-metal cocatalysts, and Z-scheme heterojunctions. Finally, the concluding remarks are presented and some perspectives regarding the future development of g-C3N4 -based photocatalysts are highlighted.

  20. Superconductivity in dense carbon-based materials

    Science.gov (United States)

    Lu, Siyu; Liu, Hanyu; Naumov, Ivan I.; Meng, Sheng; Li, Yinwei; Tse, John S.; Yang, Bai; Hemley, Russell J.

    2016-03-01

    Guided by a simple strategy in search of new superconducting materials, we predict that high-temperature superconductivity can be realized in classes of high-density materials having strong sp3 chemical bonding and high lattice symmetry. We examine in detail sodalite carbon frameworks doped with simple metals such as Li, Na, and Al. Though such materials share some common features with doped diamond, their doping level is not limited, and the density of states at the Fermi level in them can be as high as that in the renowned Mg B2 . Together with other factors, this boosts the superconducting temperature (Tc) in the materials investigated to higher levels compared to doped diamond. For example, the Tc of sodalitelike Na C6 is predicted to be above 100 K. This phase and a series of other sodalite-based superconductors are predicted to be metastable phases but are dynamically stable. Owing to the rigid carbon framework of these and related dense carbon materials, these doped sodalite-based structures could be recoverable as potentially useful superconductors.

  1. Adaptive prosthetics for the lower extremity.

    Science.gov (United States)

    Carroll, K

    2001-06-01

    The potential for lifestyle recovery is tremendous for most lower extremity amputees. The amazing and ever-expanding array of adaptive prosthetics can help make the devastating loss of amputation more bearable for patients, their families, and their health care team. The new amputee, in a state of shock and grief, does not know what his or her prosthetic options are. It is crucial that the surgeon is knowledgeable about what the patient can have and what the patient needs to ask for. Dana Bowman stated: Ideally, the new amputee should say to their doctor, "I'd like my leg to be lightweight, flexible, durable, comfortable. I want to do sports or I want to ride bikes with my kids." Whatever it is they like to do. I was told I would never be able to wear two dynamic feet and that my sky diving days were over. I said, "Well how do you know? Can't I try?" It took years to find out what I could have and then to find people to help me get it. The prosthetic prescription the physician writes is the patient's gateway to the kind of prosthetics that will enable him or her to pursue the activities of their life. Often, new amputees end up with the bare minimum prosthesis, which can cause problems with comfort and mobility. A poorly designed or badly fitting prosthesis is as disabling as the actual amputation. When the surgeon can help the amputee and his or her family understand what kind of prosthetic choices are available, it establishes an optimistic outlook that is highly beneficial to the entire recovery process physically and mentally. "When I lost my leg, if someone would have told me that I could at least try to run again, that would have meant a lot," said Brian Frasure. "Getting that positive mental attitude is every bit as important as having good medical and prosthetic care." By asking probing questions about the patient's preamputation lifestyle and postamputation goals, the physician can write a prescription for truly adaptive prosthetics. The surgeon should

  2. Prosthetic Valve Thrombosis: Diagnosis and Management.

    Science.gov (United States)

    Garg, Jalaj; Palaniswamy, Chandrasekar; Pinnamaneni, Sowmya; Sarungbam, Judy; Jain, Diwakar

    2016-01-01

    St. Jude mechanical prosthesis is the most commonly used prosthetic device with least valvular complications with excellent hemodynamics. However, prosthetic valve thrombosis is one of the serious complications, with rates between 0.03% and 0.13% per patient-year depending on the type of anticoagulation used and compliance to the therapy. Transthoracic echocardiography (TTE) is the initial screening tool (class I) that would provide clues for the assessment of valvular hemodynamics. Fluoroscopy is an alternate imaging modality for the assessment of mechanical leaflet motion, especially in patients when prosthetic valves are difficult to image on TTE or transesophageal echocardiography. A complete fluoroscopic evaluation of a prosthetic valve includes assessment of valvular motion and structural integrity. Opening and closing angles can be measured fluoroscopically to determine whether a specific valve is functioning properly. We discuss a case of a 91-year-old man with thrombosis of bileaflet mechanical mitral prosthesis that was demonstrated on real-time fluoroscopy (not evident on TTE). An algorithmic approach to diagnosis and management of prosthetic heart valve thrombosis is outlined. PMID:25486519

  3. Prototyping Cognitive Prosthetics for People with Dementia

    Science.gov (United States)

    Davies, Richard; Nugent, Chris D.; Donnelly, Mark

    In the COGKNOW project, a cognitive prosthetic has been developed through the application of Information and Communication Technology (ICT)-based services to address the unmet needs and demands of persons with dementia. The primary aim of the developed solution was to offer guidance with conducting everyday activities for persons with dementia. To encourage a user-centred design process, a three-phased methodology was introduced to facilitate cyclical prototype development. At each phase, user input was used to guide the future development. As a prerequisite to the first phase of development, user requirements were gathered to identify a small set of functional requirements from which a number of services were identified. Following implementation of these initial services, the prototype was evaluated on a cohort of users and, through observing their experiences and recording their feedback, the design was refined and the prototype redeveloped to include a number of additional services in the second phase. The current chapter provides an overview of the services designed and developed in the first two phases.

  4. Carbon nanomaterials-based electrochemical aptasensors.

    Science.gov (United States)

    Wang, Zonghua; Yu, Jianbo; Gui, Rijun; Jin, Hui; Xia, Yanzhi

    2016-05-15

    Carbon nanomaterials (CNMs) have attracted increasing attention due to their unique electrical, optical, thermal, mechanical and chemical properties. CNMs are extensively applied in electronic, optoelectronic, photovoltaic and sensing devices fields, especially in bioassay technology. These excellent properties significantly depend on not only the functional atomic structures of CNMs, but also the interactions with other materials, such as gold nanoparticles, SiO2, chitosan, etc. This review systematically summarizes applications of CNMs in electrochemical aptasensors (ECASs). Firstly, definition and development of ECASs are introduced. Secondly, different ways of ECASs about working principles, classification and construction of CNMs are illustrated. Thirdly, the applications of different CNMs used in ECASs are discussed. In this review, different types of CNMs are involved such as carbon nanotubes, graphene, graphene oxide, etc. Besides, the newly emerging CNMs and CNMs-based composites are also discoursed. Finally, we demonstrate the future prospects of CNMs-based ECASs, and some suggestions about the near future development of CNMs-based ECASs are highlighted.

  5. Carbon Ion Radiotherapy for Skull Base Chordoma

    OpenAIRE

    Mizoe, Jun–etsu; Hasegawa, Azusa; Takagi, Ryo; Bessho, Hiroki; Onda, Takeshi; Tsujii, Hirohiko

    2009-01-01

    Objective: To present the results of the clinical study of carbon ion radiotherapy (CIRT) for skull base and paracervical spine tumors at the National Institute of Radiological Sciences in Chiba, Japan. Methods: The study is comprised of three protocols: a pilot study, a phase I/II dose escalation study, and a phase II study. All the patients were treated by 16 fractions for 4 weeks with total doses of 48.0, 52.8, 57.6, and 60.8 Gy equivalents (GyE). Results: As a result of the dose escalatio...

  6. Carbon-based ion and molecular channels

    Science.gov (United States)

    Sint, Kyaw; Wang, Boyang; Kral, Petr

    2008-03-01

    We design ion and molecular channels based on layered carboneous materials, with chemically-functionalized pore entrances. Our molecular dynamics simulations demonstrate that these ultra-narrow pores, with diameters around 1 nm, are highly selective to the charges and sizes of the passing (Na^+ and Cl^-) ions and short alkanes. We demonstrate that the molecular flows through these pores can be easily controlled by electrical and mechanical means. These artificial pores could be integrated in fluidic nanodevices and lab-on-a-chip techniques with numerous potential applications. [1] Kyaw Sint, Boyang Wang and Petr Kral, submitted. [2] Boyang Wang and Petr Kral, JACS 128, 15984 (2006).

  7. Raoultella ornithinolytica: An unusual pathogen for prosthetic joint infection.

    Science.gov (United States)

    Seng, Piseth; Theron, Françoise; Honnorat, Estelle; Prost, Didier; Fournier, Pierre-Edouard; Stein, Andreas

    2016-01-01

    We herein report the first case of a prosthetic joint infection caused by Raoultella ornithinolytica in an immunocompetent patient. The clinical outcome was favorable after a two-stage prosthetic exchange and a six-month course of antimicrobial therapy.

  8. Adsorption over polyacrylonitrile based carbon monoliths

    Science.gov (United States)

    Nandi, Mahasweta; Dutta, Arghya; Patra, Astam Kumar; Bhaumik, Asim; Uyama, Hiroshi

    2013-02-01

    Highly porous activated carbon monoliths have been prepared from mesoporous polyacrylonitrile (PAN) monolith as the carbon precursor. The mesoporous PAN monoliths are fabricated by a unique and facile template-free method which on carbonization gives N-doped activated carbon monoliths. The carbonization is achieved via two step thermal process which includes pretreatment in air leading to cyclization and subsequent aromatization of the PAN moieties followed by carbonization in a mixture of argon and carbon dioxide to give a layered carbon framework. Nitrogen sorption experiments carried over these carbon monoliths revealed high surface area (ca. 2500 m2g-1) for these materials with precise micropore size distribution. The activated carbons show extraordinarily high CO2 capture capacity and the uptake up to 3 bar has been found to be as high as 22.5 and 10.6 mmol/g at 273 K and 298 K, respectively.

  9. Biomechanical characteristics, patient preference and activity level with different prosthetic feet: a randomized double blind trial with laboratory and community testing.

    Science.gov (United States)

    Raschke, Silvia U; Orendurff, Michael S; Mattie, Johanne L; Kenyon, David E A; Jones, O Yvette; Moe, David; Winder, Lorne; Wong, Angie S; Moreno-Hernández, Ana; Highsmith, M Jason; J Sanderson, David; Kobayashi, Toshiki

    2015-01-01

    Providing appropriate prosthetic feet to those with limb loss is a complex and subjective process influenced by professional judgment and payer guidelines. This study used a small load cell (Europa™) at the base of the socket to measure the sagittal moments during walking with three objective categories of prosthetic feet in eleven individuals with transtibial limb loss with MFCL K2, K3 and K4 functional levels. Forefoot stiffness and hysteresis characteristics defined the three foot categories: Stiff, Intermediate, and Compliant. Prosthetic feet were randomly assigned and blinded from participants and investigators. After laboratory testing, participants completed one week community wear tests followed by a modified prosthetics evaluation questionnaire to determine if a specific category of prosthetic feet was preferred. The Compliant category of prosthetic feet was preferred by the participants (P=0.025) over the Stiff and Intermediate prosthetic feet, and the Compliant and Intermediate feet had 15% lower maximum sagittal moments during walking in the laboratory (P=0.0011) compared to the Stiff feet. The activity level of the participants did not change significantly with any of the wear tests in the community, suggesting that each foot was evaluated over a similar number of steps, but did not inherently increase activity. This is the first randomized double blind study in which prosthetic users have expressed a preference for a specific biomechanical characteristic of prosthetic feet: those with lower peak sagittal moments were preferred, and specifically preferred on slopes, stairs, uneven terrain, and during turns and maneuvering during real world use.

  10. The role of virtual articulator in prosthetic and restorative dentistry.

    Science.gov (United States)

    Koralakunte, Pavankumar Ravi; Aljanakh, Mohammad

    2014-07-01

    Virtual reality is a computer based technology linked with the future of dentistry and dental practice. The virtual articulator is one such application in prosthetic and restorative dentistry based on virtual reality that will significantly reduce the limitations of the mechanical articulator, and by simulation of real patient data, allow analyses with regard to static and dynamic occlusion as well as to jaw relation. It is the purpose of this article to present the concepts and strategies for a future replacement of the mechanical articulator by a virtual one. Also, a brief note on virtual reality haptic system has been highlighted along with newly developed touch enabled virtual articulator.

  11. Mesofluidic controlled robotic or prosthetic finger

    Energy Technology Data Exchange (ETDEWEB)

    Lind, Randall F; Jansen, John F; Love, Lonnie J

    2013-11-19

    A mesofluidic powered robotic and/or prosthetic finger joint includes a first finger section having at least one mesofluidic actuator in fluid communication with a first actuator, a second mesofluidic actuator in fluid communication with a second actuator and a second prosthetic finger section pivotally connected to the first finger section by a joint pivot, wherein the first actuator pivotally cooperates with the second finger to provide a first mechanical advantage relative to the joint point and wherein the second actuator pivotally cooperates with the second finger section to provide a second mechanical advantage relative to the joint point.

  12. Comparative roll-over analysis of prosthetic feet

    NARCIS (Netherlands)

    Curtze, Carolin; Hof, At L.; van Keeken, Helco G.; Halbertsma, Jan P. K.; Postema, Klaas; Otten, Bert

    2009-01-01

    A prosthetic foot is a key element of a prosthetic leg, literally forming the basis for a stable and efficient amputee gait. We determined the roll-over characteristics of a broad range of prosthetic feet and examined the effect of a variety of shoes on these characteristics. The body weight of a pe

  13. Carbon Based Transistors and Nanoelectronic Devices

    Science.gov (United States)

    Rouhi, Nima

    Carbon based materials (carbon nanotube and graphene) has been extensively researched during the past decade as one of the promising materials to be used in high performance device technology. In long term it is thought that they may replace digital and/or analog electronic devices, due to their size, near-ballistic transport, and high stability. However, a more realistic point of insertion into market may be the printed nanoelectronic circuits and sensors. These applications include printed circuits for flexible electronics and displays, large-scale bendable electrical contacts, bio-membranes and bio sensors, RFID tags, etc. In order to obtain high performance thin film transistors (as the basic building block of electronic circuits) one should be able to manufacture dense arrays of all semiconducting nanotubes. Besides, graphene synthesize and transfer technology is in its infancy and there is plenty of room to improve the current techniques. To realize the performance of nanotube and graphene films in such systems, we need to economically fabricate large-scale devices based on these materials. Following that the performance control over such devices should also be considered for future design variations for broad range of applications. Here we have first investigated carbon nanotube ink as the base material for our devices. The primary ink used consisted of both metallic and semiconducting nanotubes which resulted in networks suitable for moderate-resistivity electrical connections (such as interconnects) and rfmatching circuits. Next, purified all-semiconducting nanotube ink was used to fabricate waferscale, high performance (high mobility, and high on/off ratio) thin film transistors for printed electronic applications. The parameters affecting device performance were studied in detail to establish a roadmap for the future of purified nanotube ink printed thin film transistors. The trade of between mobility and on/off ratio of such devices was studied and the

  14. Yeast-based microporous carbon materials for carbon dioxide capture.

    Science.gov (United States)

    Shen, Wenzhong; He, Yue; Zhang, Shouchun; Li, Junfen; Fan, Weibin

    2012-07-01

    A hierarchical microporous carbon material with a Brunauer-Emmett-Teller surface area of 1348 m(2) g(-1) and a pore volume of 0.67 cm(3) g(-1) was prepared from yeast through chemical activation with potassium hydroxide. This type of material contains large numbers of nitrogen-containing groups (nitrogen content >5.3 wt%), and, consequently, basic sites. As a result, this material shows a faster adsorption rate and a higher adsorption capacity of CO(2) than the material obtained by directly carbonizing yeast under the same conditions. The difference is more pronounced in the presence of N(2) or H(2)O, showing that chemical activation of discarded yeast with potassium hydroxide could afford high-performance microporous carbon materials for the capture of CO(2).

  15. Myoelectric control of prosthetic hands: state-of-the-art review

    Directory of Open Access Journals (Sweden)

    Geethanjali P

    2016-07-01

    Full Text Available Purushothaman Geethanjali School of Electrical Engineering Department of Control and Automation VIT University, Vellore, Tamil Nadu, India Abstract: Myoelectric signals (MES have been used in various applications, in particular, for identification of user intention to potentially control assistive devices for amputees, orthotic devices, and exoskeleton in order to augment capability of the user. MES are also used to estimate force and, hence, torque to actuate the assistive device. The application of MES is not limited to assistive devices, and they also find potential applications in teleoperation of robots, haptic devices, virtual reality, and so on. The myoelectric control-based prosthetic hand aids to restore activities of daily living of amputees in order to improve the self-esteem of the user. All myoelectric control-based prosthetic hands may not have similar operations and exhibit variation in sensing input, deciphering the signals, and actuating prosthetic hand. Researchers are focusing on improving the functionality of prosthetic hand in order to suit the user requirement with the different operating features. The myoelectric control differs in operation to accommodate various external factors. This article reviews the state of the art of myoelectric prosthetic hand, giving description of each control strategy. Keywords: EMG, assistive device, amputee, myoelectric control, electric powered, body ­powered, bioelectric signal control

  16. Myoelectric control of prosthetic hands: state-of-the-art review.

    Science.gov (United States)

    Geethanjali, Purushothaman

    2016-01-01

    Myoelectric signals (MES) have been used in various applications, in particular, for identification of user intention to potentially control assistive devices for amputees, orthotic devices, and exoskeleton in order to augment capability of the user. MES are also used to estimate force and, hence, torque to actuate the assistive device. The application of MES is not limited to assistive devices, and they also find potential applications in teleoperation of robots, haptic devices, virtual reality, and so on. The myoelectric control-based prosthetic hand aids to restore activities of daily living of amputees in order to improve the self-esteem of the user. All myoelectric control-based prosthetic hands may not have similar operations and exhibit variation in sensing input, deciphering the signals, and actuating prosthetic hand. Researchers are focusing on improving the functionality of prosthetic hand in order to suit the user requirement with the different operating features. The myoelectric control differs in operation to accommodate various external factors. This article reviews the state of the art of myoelectric prosthetic hand, giving description of each control strategy. PMID:27555799

  17. Fermentation based carbon nanotube multifunctional bionic composites

    Science.gov (United States)

    Valentini, Luca; Bon, Silvia Bittolo; Signetti, Stefano; Tripathi, Manoj; Iacob, Erica; Pugno, Nicola M.

    2016-06-01

    The exploitation of the processes used by microorganisms to digest nutrients for their growth can be a viable method for the formation of a wide range of so called biogenic materials that have unique properties that are not produced by abiotic processes. Here we produced living hybrid materials by giving to unicellular organisms the nutrient to grow. Based on bread fermentation, a bionic composite made of carbon nanotubes (CNTs) and a single-cell fungi, the Saccharomyces cerevisiae yeast extract, was prepared by fermentation of such microorganisms at room temperature. Scanning electron microscopy analysis suggests that the CNTs were internalized by the cell after fermentation bridging the cells. Tensile tests on dried composite films have been rationalized in terms of a CNT cell bridging mechanism where the strongly enhanced strength of the composite is governed by the adhesion energy between the bridging carbon nanotubes and the matrix. The addition of CNTs also significantly improved the electrical conductivity along with a higher photoconductive activity. The proposed process could lead to the development of more complex and interactive structures programmed to self-assemble into specific patterns, such as those on strain or light sensors that could sense damage or convert light stimulus in an electrical signal.

  18. Fermentation based carbon nanotube multifunctional bionic composites

    Science.gov (United States)

    Valentini, Luca; Bon, Silvia Bittolo; Signetti, Stefano; Tripathi, Manoj; Iacob, Erica; Pugno, Nicola M.

    2016-01-01

    The exploitation of the processes used by microorganisms to digest nutrients for their growth can be a viable method for the formation of a wide range of so called biogenic materials that have unique properties that are not produced by abiotic processes. Here we produced living hybrid materials by giving to unicellular organisms the nutrient to grow. Based on bread fermentation, a bionic composite made of carbon nanotubes (CNTs) and a single-cell fungi, the Saccharomyces cerevisiae yeast extract, was prepared by fermentation of such microorganisms at room temperature. Scanning electron microscopy analysis suggests that the CNTs were internalized by the cell after fermentation bridging the cells. Tensile tests on dried composite films have been rationalized in terms of a CNT cell bridging mechanism where the strongly enhanced strength of the composite is governed by the adhesion energy between the bridging carbon nanotubes and the matrix. The addition of CNTs also significantly improved the electrical conductivity along with a higher photoconductive activity. The proposed process could lead to the development of more complex and interactive structures programmed to self-assemble into specific patterns, such as those on strain or light sensors that could sense damage or convert light stimulus in an electrical signal. PMID:27279425

  19. A cell nanoinjector based on carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xing; Kis, Andras; Zettl, Alex; Bertozzi, Carolyn R.

    2007-01-30

    Technologies for introducing molecules into living cells are vital for probing the physical properties and biochemical interactions that govern the cell's behavior. Here we report the development of a nanoscale cell injection system-termed the nanoinjector-that uses carbon nanotubes to deliver cargo into cells. A single multi-walled carbon nanotube attached to an atomic force microscope tip was functionalized with cargo via a disulfide-based linker. Penetration of cell membranes with this 'nanoneedle', followed by reductive cleavage of the disulfide bonds within the cell's interior, resulted in the release of cargo inside the cells. The capability of the nanoinjector was demonstrated by injection of protein-coated quantum dots into live human cells. Single-particle tracking was employed to characterize the diffusion dynamics of injected quantum dots in the cytosol. This new technique causes no discernible membrane or cell damage, and can deliver a discrete number of molecules to the cell's interior without the requirement of a carrier solvent.

  20. Fast Electromechanical Switches Based on Carbon Nanotubes

    Science.gov (United States)

    Kaul, Anupama; Wong, Eric; Epp, Larry

    2008-01-01

    Electrostatically actuated nanoelectromechanical switches based on carbon nanotubes have been fabricated and tested in a continuing effort to develop high-speed switches for a variety of stationary and portable electronic equipment. As explained below, these devices offer advantages over electrostatically actuated microelectromechanical switches, which, heretofore, have represented the state of the art of rapid, highly miniaturized electromechanical switches. Potential applications for these devices include computer memories, cellular telephones, communication networks, scientific instrumentation, and general radiation-hard electronic equipment. A representative device of the present type includes a single-wall carbon nanotube suspended over a trench about 130 nm wide and 20 nm deep in an electrically insulating material. The ends of the carbon nanotube are connected to metal electrodes, denoted the source and drain electrodes. At bottom of the trench is another metal electrode, denoted the pull electrode (see figure). In the off or open switch state, no voltage is applied, and the nanotube remains out of contact with the pull electrode. When a sufficiently large electric potential (switching potential) is applied between the pull electrode and either or both of the source and drain electrodes, the resulting electrostatic attraction bends and stretches the nanotube into contact with the pull electrode, thereby putting the switch into the "on" or "closed" state, in which substantial current (typically as much as hundreds of nanoamperes) is conducted. Devices of this type for use in initial experiments were fabricated on a thermally oxidized Si wafer, onto which Nb was sputter-deposited for use as the pull-electrode layer. Nb was chosen because its refractory nature would enable it to withstand the chemical and thermal conditions to be subsequently imposed for growing carbon nanotubes. A 200- nm-thick layer of SiO2 was formed on top of the Nb layer by plasma

  1. Recent advancements in prosthetic hand technology.

    Science.gov (United States)

    Saikia, Angana; Mazumdar, Sushmi; Sahai, Nitin; Paul, Sudip; Bhatia, Dinesh; Verma, Suresh; Rohilla, Punit Kumar

    2016-07-01

    Recently, significant advances over the past decade have been made in robotics, artificial intelligence and other cognitive related fields, allowing development of highly sophisticated bio-mimetic robotics systems. In addition, enormous number of robots have been designed and assembled by explicitly realising their biological oriented behaviours. To enhance skill behaviours and adequate grasping abilities in these devices, a new phase of dexterous hands has been developed recently with bio-mimetically oriented and bio-inspired functionalities. The aim in writing this review paper is to present a detailed insight towards the development of the bio-mimetic based dexterous robotic multi-fingered artificial hand. An "ideal" upper limb prosthesis should be perceived as a part of their natural body by the amputee and should replicate sensory-motor capabilities of the amputated limb. Upper-limb amputations are most often the result of sudden trauma to the body, although they also can be caused by malignancy, congenital deficiencies and vascular diseases. This paper discusses the different bio-mimetic approaches using a framework that permits for a common description of biological and technical based hand manipulation behaviour. In particular, the review focuses on a number of developments in the inspired robotic systems. In conclusion, the study found that a huge amount of research efforts in terms of kinematics, dynamics, modelling and control methodologies are being put in to improve the present hand technology, thereby providing more functionality to the prosthetic limb of the amputee. This would improve their quality-of-life and help in performing activities of daily living (ADL) tasks with comparative ease in the near future. PMID:27098838

  2. Carbon-nanotube-based photonic devices

    Science.gov (United States)

    Yamashita, Shinji

    2007-11-01

    We recently proposed and demonstrated a saturable absorber (SA) incorporating carbon nanotube (CNT). CNT-based SA offers several key advantages such as: ultra-fast recovery time, polarization insensitivity, high optical damage threshold, mechanical and environmental robustness, chemical stability, and the ability to operate at wide range of wavelength bands. Using the CNT-based SA, we have realized femtosecond fiber pulsed lasers at various wavelengths, as well as the very short-cavity fiber laser having high repetition rate. Besides the saturable absorption, CNT has been shown to have high third-order nonlinearity, which is also attractive for realization of compact and integrated functional photonic devices, such as all-optical switches and wavelength converters. In this paper, we first present photonic properties of CNTs, and review our studies on CNT-based mode-locked fiber lasers. We also refer to fabrication methods of CNT-based photonic devices. We show our recent research progresses on novel photonic devices using evanescent coupling between optical field and CNT.

  3. Carbon nanotube based stationary phases for microchip chromatography

    DEFF Research Database (Denmark)

    Mogensen, Klaus Bo; Kutter, Jörg Peter

    2012-01-01

    The objective of this article is to provide an overview and critical evaluation of the use of carbon nanotubes and related carbon-based nanomaterials for microchip chromatography. The unique properties of carbon nanotubes, such as a very high surface area and intriguing adsorptive behaviour, have...

  4. Dynamic Facial Prosthetics for Sufferers of Facial Paralysis

    Directory of Open Access Journals (Sweden)

    Fergal Coulter

    2011-10-01

    Full Text Available BackgroundThis paper discusses the various methods and the materialsfor the fabrication of active artificial facial muscles. Theprimary use for these will be the reanimation of paralysedor atrophied muscles in sufferers of non-recoverableunilateral facial paralysis.MethodThe prosthetic solution described in this paper is based onsensing muscle motion of the contralateral healthy musclesand replicating that motion across a patient’s paralysed sideof the face, via solid state and thin film actuators. Thedevelopment of this facial prosthetic device focused onrecreating a varying intensity smile, with emphasis ontiming, displacement and the appearance of the wrinklesand folds that commonly appear around the nose and eyesduring the expression.An animatronic face was constructed with actuations beingmade to a silicone representation musculature, usingmultiple shape-memory alloy cascades. Alongside theartificial muscle physical prototype, a facial expressionrecognition software system was constructed. This formsthe basis of an automated calibration and reconfigurationsystem for the artificial muscles following implantation, soas to suit the implantee’s unique physiognomy.ResultsAn animatronic model face with silicone musculature wasdesigned and built to evaluate the performance of ShapeMemory Alloy artificial muscles, their power controlcircuitry and software control systems. A dual facial motionsensing system was designed to allow real time control overmodel – a piezoresistive flex sensor to measure physicalmotion, and a computer vision system to evaluate real toartificial muscle performance.Analysis of various facial expressions in real subjects wasmade, which give useful data upon which to base thesystems parameter limits.ConclusionThe system performed well, and the various strengths andshortcomings of the materials and methods are reviewedand considered for the next research phase, when newpolymer based artificial muscles are constructed

  5. Carbon-Nanotube-Based Chemical Gas Sensor

    Science.gov (United States)

    Kaul, Arunpama B.

    2010-01-01

    Conventional thermal conductivity gauges (e.g. Pirani gauges) lend themselves to applications such as leak detectors, or in gas chromatographs for identifying various gas species. However, these conventional gauges are physically large, operate at high power, and have a slow response time. A single-walled carbon-nanotube (SWNT)-based chemical sensing gauge relies on differences in thermal conductance of the respective gases surrounding the CNT as it is voltage-biased, as a means for chemical identification. Such a sensor provides benefits of significantly reduced size and compactness, fast response time, low-power operation, and inexpensive manufacturing since it can be batch-fabricated using Si integrated-circuit (IC) process technology.

  6. Carbon Nanotube-Based Chemical Sensors.

    Science.gov (United States)

    Meyyappan, M

    2016-04-27

    The need to sense gases and vapors arises in numerous scenarios in industrial, environmental, security and medical applications. Traditionally, this activity has utilized bulky instruments to obtain both qualitative and quantitative information on the constituents of the gas mixture. It is ideal to use sensors for this purpose since they are smaller in size and less expensive; however, their performance in the field must match that of established analytical instruments in order to gain acceptance. In this regard, nanomaterials as sensing media offer advantages in sensitivity, preparation of chip-based sensors and construction of electronic nose for selective detection of analytes of interest. This article provides a review of the use of carbon nanotubes in gas and vapor sensing. PMID:26959284

  7. 基于动态阈值的肌电假手动作控制方法研究%Movement Pattern Control for Prosthetic Hand Based on a Method of Dynamic Threshold

    Institute of Scientific and Technical Information of China (English)

    喻洪流; 胡加华

    2011-01-01

    由于构成肌电信号采集电路的电子元器件性能不可能完全对称及干扰信号的存在,有时会导致两路肌电信号发生阈值不一致。这时仍采用固定阈值来对两路肌电信号控制的动作进行判别,会导致动作的误判率增加。为了提高对假手动作判别的正确率,本文提出了利用动态阈值对假手动作进行判别。实验结果表明,利用动态阈值对假手动作进行判别,能够提高对动作判别的正确率达约10%。%Due to the function asymmetry of electrical components used for EMG signal acquisition circuit and the existing of undesired signals, sometimes thresholds for judging EMG's occur may be incongruent. If a fixed threshold is used to recognize Prosthetic Hand's movement,the matching rate of prosthetic hand's movement pattern recognition will be increased. In order to improve prosthetic hand's movement pattern recognition, a method of dynamic threshold was used to recognize the prosthetic hand's movement. The exprimental results showed that the method of dynamic threshold can obviously improve Prosthetic Hand's movement pattern recognition by about 10%.

  8. Multimodality Imaging Assessment of Prosthetic Heart Valves

    NARCIS (Netherlands)

    Suchá, D.; Symersky, Petr; Tanis, W; Mali, Willem P Th M; Leiner, Tim; van Herwerden, LA; Budde, Ricardo P J

    2015-01-01

    Echocardiography and fluoroscopy are the main techniques for prosthetic heart valve (PHV) evaluation, but because of specific limitations they may not identify the morphological substrate or the extent of PHV pathology. Cardiac computed tomography (CT) and magnetic resonance imaging (MRI) have emerg

  9. Consumer satisfaction in prosthetics and orthotics facilities

    NARCIS (Netherlands)

    Geertzen, J.H.B.; Gankema, H.G.J.; Groothoff, J.W.; Dijkstra, P.U.

    2002-01-01

    The aim of this study was to assess consumer/patient satisfaction with the services of the prosthetics and orthotics (P&O) facilities in the north of the Netherlands, using a modified SERVQUAL questionnaire. In this questionnaire, consumer interests and experiences are assessed on a 5-point Likert s

  10. Analytical modeling of glucose biosensors based on carbon nanotubes

    OpenAIRE

    Pourasl, Ali H; Ahmadi, Mohammad Taghi; Rahmani, Meisam; Chin, Huei Chaeng; Lim, Cheng Siong; Ismail, Razali; Tan, Michael Loong Peng

    2014-01-01

    In recent years, carbon nanotubes have received widespread attention as promising carbon-based nanoelectronic devices. Due to their exceptional physical, chemical, and electrical properties, namely a high surface-to-volume ratio, their enhanced electron transfer properties, and their high thermal conductivity, carbon nanotubes can be used effectively as electrochemical sensors. The integration of carbon nanotubes with a functional group provides a good and solid support for the immobilization...

  11. Nanostructure-based Processes at the Carbonizing Steels

    Directory of Open Access Journals (Sweden)

    L.I. Roslyakova

    2015-12-01

    Full Text Available The studies of nanostructure-based processes carburizing steels showed that oxidizing atmosphere when carburizing steel contains along with carbon dioxide (CO2 + C = 2CO molecular and atmospheric oxygen (O2 + 2C = 2CO; O + C = CO released from the carbonate ВаСОз during its thermal dissociation. Intensive formation of CO provides high carbonizing ability of carbonate-soot coating and steel.

  12. Carbonation Resistance of Sulphoaluminate Cement-based High Performance Concrete

    Institute of Scientific and Technical Information of China (English)

    ZHANG Decheng; XU Dongyu; CHENG Xin; CHEN Wen

    2009-01-01

    The influences of water/cement ratio and admixtures on carbonation resistance of sulphoaluminate cement-based high performance concrete(HPC)were investigated.The experimental results show that with the decreasing water/cement ratio,the carbonation depth of sulphoaluminate cement-based HPC is decreased remarkably,and the carbonation resistance capability is also improved with the adding admixtures.The morphologies and structure characteristics of sulphoaluminate cement hydration products before and after carbonation were analyzed using SEM and XRD.The analysis results reveal that the main hydration product of sulphoaluminate cement,that is ettringite(AFt),de-composes after carbonation.

  13. Prosthetic cost projections for servicemembers with major limb loss from Vietnam and OIF/OEF

    Directory of Open Access Journals (Sweden)

    David K. Blough, PhD

    2010-07-01

    Full Text Available This study projects prosthetic- and assistive-device costs for veterans with limb loss from Vietnam and injured servicemembersreturning from Operation Iraqi Freedom (OIF and Operation Enduring Freedom (OEF to inform the Department of Veterans Affairs (VA for these veterans’ future care. The 2005 Medicare prosthetic device component prices were applied to current prosthetic and assistive-device use obtained from a national survey of 581 veterans and servicemembers with major traumatic amputations. Projections were made for 5-year, 10-year, 20-year, and lifetime costs based on eight Markov models.Average 5-year projected costs for prosthetic and assistive-device replacement for the Vietnam group are lower than for the OIF/OEF cohort due in part to use of fewer and less technologicallyadvanced prosthetic devices and higher frequency of prostheticabandonment. By limb-loss level, for the Vietnam group and OIF/OEF cohort, 5-year projected unilateral upper limb average costs are $31,129 and $117,440, unilateral lower limb costs are $82,251 and $228,665, and multiple limb costs are $130,890 and $453,696, respectively. These figures provide the VA with a funding estimate for technologically advanced prostheticand assistive devices within the framework of ongoing rehabilitation for veterans with traumatic limb loss from the Vietnam and OIF/OEF conflicts.

  14. Device to monitor sock use in people using prosthetic limbs: Technical report

    Directory of Open Access Journals (Sweden)

    Joan E. Sanders, PhD

    2012-12-01

    Full Text Available A device using radio frequency identification (RFID technology was developed to continuously monitor sock use in people who use prosthetic limbs. RFID tags were placed on prosthetic socks worn by subjects with transtibial limb loss, and a high-frequency RFID reader and antenna were placed in a portable unit mounted to the outside of the prosthetic socket. Bench testing showed the device to have a maximum read range between 5.6 cm and 12.7 cm, depending on the RFID tag used. Testing in a laboratory setting on three participants with transtibial amputation showed that the device correctly monitored sock presence during sitting, standing, and walking activity when one or two socks were worn but was less reliable when more socks were used. Accurate detection was sensitive to orientation of the tag relative to the reader, presence of carbon fiber in the prosthetic socket, pistoning of the limb in the socket, and overlap among the tags. Use of ultra-high-­frequency RFID may overcome these limitations. With improvements, the technology may prove useful to practitioners prescribing volume accommodation strategies for patients by providing information about sock use between clinical visits, including timing and consistency of daily sock-ply changes.

  15. A critical review of glucose biosensors based on carbon nanomaterials: carbon nanotubes and graphene.

    Science.gov (United States)

    Zhu, Zhigang; Garcia-Gancedo, Luis; Flewitt, Andrew J; Xie, Huaqing; Moussy, Francis; Milne, William I

    2012-01-01

    There has been an explosion of research into the physical and chemical properties of carbon-based nanomaterials, since the discovery of carbon nanotubes (CNTs) by Iijima in 1991. Carbon nanomaterials offer unique advantages in several areas, like high surface-volume ratio, high electrical conductivity, chemical stability and strong mechanical strength, and are thus frequently being incorporated into sensing elements. Carbon nanomaterial-based sensors generally have higher sensitivities and a lower detection limit than conventional ones. In this review, a brief history of glucose biosensors is firstly presented. The carbon nanotube and grapheme-based biosensors, are introduced in Sections 3 and 4, respectively, which cover synthesis methods, up-to-date sensing approaches and nonenzymatic hybrid sensors. Finally, we briefly outline the current status and future direction for carbon nanomaterials to be used in the sensing area. PMID:22778628

  16. A Critical Review of Glucose Biosensors Based on Carbon Nanomaterials: Carbon Nanotubes and Graphene

    Directory of Open Access Journals (Sweden)

    William I. Milne

    2012-05-01

    Full Text Available There has been an explosion of research into the physical and chemical properties of carbon-based nanomaterials, since the discovery of carbon nanotubes (CNTs by Iijima in 1991. Carbon nanomaterials offer unique advantages in several areas, like high surface-volume ratio, high electrical conductivity, chemical stability and strong mechanical strength, and are thus frequently being incorporated into sensing elements. Carbon nanomaterial-based sensors generally have higher sensitivities and a lower detection limit than conventional ones. In this review, a brief history of glucose biosensors is firstly presented. The carbon nanotube and grapheme-based biosensors, are introduced in Sections 3 and 4, respectively, which cover synthesis methods, up-to-date sensing approaches and nonenzymatic hybrid sensors. Finally, we briefly outline the current status and future direction for carbon nanomaterials to be used in the sensing area.

  17. Carbon-based electrode materials for DNA electroanalysis.

    Science.gov (United States)

    Kato, Dai; Niwa, Osamu

    2013-01-01

    This review addresses recent studies of newly developed carbon-based electrode materials and their use for DNA electroanalysis. Recently, new carbon materials including carbon nanotubes (CNT), graphene and diamond-based nanocarbon electrodes have been actively developed as sensing platforms for biomolecules, such as DNA and proteins. Electrochemical techniques using these new material-based electrodes can provide very simple and inexpensive sensing platforms, and so are expected to be used as one of the "post-light" DNA analysis methods, which include coulometric detection, amperometric detection with electroactive tags or intercalators, and potentiometric detection. DNA electroanalysis using these new carbon materials is summarized in view of recent advances on electrodes.

  18. Polymer composite material structures comprising carbon based conductive loads

    OpenAIRE

    Jérôme, Robert; Pagnoulle, Christophe; Detrembleur, Christophe; Thomassin, Jean-Michel; Huynen, Isabelle; Bailly, Christian; Bednarz, Luikasz; Daussin, Raphaël; Saib, Aimad; Baudouin, Anne-Christine; Laloyaux, Xavier

    2007-01-01

    The present invention provides a polymer composite material structure comprising at least one layer of a foamed polymer composite material comprising a foamed polymer matrix and 0.1 wt % to 6 wt % carbon based conductive loads, such as e.g. carbon nanotubes, dispersed in the foamed polymer matrix. The polymer composite material structure according to embodiments of the present invention shows good shielding and absorbing properties notwithstanding the low amount of carbon based conductive loa...

  19. Polymer composite material structures comprising carbon based conductive loads

    OpenAIRE

    Jérôme, Robert; Pagnoulle, Christophe; Detrembleur, Christophe; Thomassin, Jean-Michel; Huynen, Isabelle; Bailly, Christian; Bednarz, Lucasz; Daussin, Raphaël; Saib, Aimad

    2006-01-01

    The present invention provides a polymer composite material structure comprising at least one layer of a foamed polymer composite material comprising a foamed polymer matrix and 0.1 to 6 wt% carbon based conductive loads, such as e.g. carbon nanotubes, dispersed in the foamed polymer matrix. The polymer composite material structure according to embodiments of the present invention shows good shielding and absorbing properties notwithstanding the low amount of carbon based conductive loads. Th...

  20. Carbon nanomaterial based electrochemical sensors for biogenic amines

    International Nuclear Information System (INIS)

    This review describes recent advances in the use of carbon nanomaterials for electroanalytical detection of biogenic amines (BAs). It starts with a short introduction into carbon nanomaterials such as carbon nanotubes, graphene, nanodiamonds, carbon nanofibers, fullerenes, and their composites. Next, electrochemical sensing schemes are discussed for various BAs including dopamine, serotonin, epinephrine, norepinephrine, tyramine, histamine and putrescine. Examples are then given for methods for simultaneous detection of various BAs. Finally, we discuss the current and future challenges of carbon nanomaterial-based electrochemical sensors for BAs. The review contains 175 references. (author)

  1. Metal-carbon nanocomposites based on activated IR pyrolized polyacrylonitrile

    Science.gov (United States)

    Efimov, Mikhail N.; Zhilyaeva, Natalya A.; Vasilyev, Andrey A.; Muratov, Dmitriy G.; Zemtsov, Lev M.; Karpacheva, Galina P.

    2016-05-01

    In this paper we report about new approach to preparation of metal-carbon nanocomposites based on activated carbon. Polyacrylonitrile is suggested as a precursor for Co, Pd and Ru nanoparticles carbon support which is prepared under IR pyrolysis conditions of a precursor. The first part of the paper is devoted to study activated carbon structural characteristics dependence on activation conditions. In the second part the effect of type of metal introduced in precursor on metal-carbon nanocomposite structural characteristics is shown. Prepared AC and nanocomposite samples are characterized by BET, TEM, SEM and X-ray diffraction.

  2. Coal-based carbons with molecular sieve properties

    Energy Technology Data Exchange (ETDEWEB)

    El-Wakil, A.M.; Youssef, A.M.; Tollan, K.A. (Mansoura Univ. (Egypt))

    1991-01-01

    Carbon molecular sieves are used extensively in gas chromatography for the separation of permanent gases and light hydrocarbons. Carbon molecular sieves also find commercial application for the manufacture of pure hydrogen from hydrogen-rich gases such as coke-oven gas, and for the separation of air by the pressure-swing adsorption technique. The objective of this investigation was to prepare carbons from Maghara coal, recently available on the commercial market. Coal-based carbons, if they possess molecular sieve properties, are superior to molecular sieve carbons from agricultural by-products because they have more satisfactory mechanical properties.

  3. Carbon nanotube based NEMS actuators and sensors

    Science.gov (United States)

    Forney, Michael; Poler, Jordan

    2011-03-01

    Single-walled carbon nanotubes (SWNTs) have been widely studied due to superior mechanical and electrical properties. We have grown vertically aligned SWNTs (VA-SWNTs) onto microcantilever (MC) arrays, which provides an architecture for novel actuators and sensors. Raman spectroscopy confirms that the CVD-grown nanotubes are SWNTs and SEM confirms aligned growth. As an actuator, this hybrid MC/VA-SWNT system can be electrostatically modulated. SWNTs are excellent electron acceptors, so we can charge up the VA-SWNT array by applying a voltage. The electrostatic repulsion among the charged SWNTs provides a surface stress that induces MC deflection. Simulation results show that a few electrons per SWNT are needed for measureable deflections, and experimental actuators are being characterized by SEM, Raman, and an AFM optical lever system. The applied voltage is sinusoidally modulated, and deflection is measured with a lock-in amplifier. These actuators could be used for nano-manipulation, release of drugs from a capsule, or nano-valves. As a sensor, this MC/VA-SWNT system offers an improved sensitivity for chemical and bio-sensing compared to surface functionalized MC-based sensors. Those sensors only have a 2D sensing surface, but a MC/VA-SWNT system has significantly more sensing surface because the VA-SWNTs extend microns off the MC surface.

  4. Pristine carbon nanotubes based resistive temperature sensor

    Science.gov (United States)

    Alam, Md Bayazeed; Saini, Sudhir Kumar; Sharma, Daya Shankar; Agarwal, Pankaj B.

    2016-04-01

    A good sensor must be highly sensitive, faster in response, of low cost cum easily producible, and highly reliable. Incorporation of nano-dimensional particles/ wires makes conventional sensors more effective in terms of fulfilling the above requirements. For example, Carbon Nanotubes (CNTs) are promising sensing element because of its large aspect ratio, unique electronic and thermal properties. In addition to their use for widely reported chemical sensing, it has also been explored for temperature sensing. This paper presents the fabrication of CNTs based temperature sensor, prepared on silicon substrate using low cost spray coating method, which is reliable and reproducible method to prepare uniform CNTs thin films on any substrate. Besides this, simple and inexpensive method of preparation of dispersion of single walled CNTs (SWNTs) in 1,2 dichlorobenzene by using probe type ultrasonicator for debundling the CNTs for improving sensor response were used. The electrical contacts over the dispersed SWNTs were taken using silver paste electrodes. Fabricated sensors clearly show immediate change in resistance as a response to change in temperature of SWNTs. The measured sensitivity (change in resistance with temperature) of the sensor was found ˜ 0.29%/°C in the 25°C to 60°C temperature range.

  5. Preliminary MRI study on hemodynamics after prosthetic cardiac valve implantation

    International Nuclear Information System (INIS)

    Objective: To assess the function of prosthetic valve by magnetic resonance imaging (MRI), and to measure the blood velocity downstream of prosthetic valve and three-dimensional surface profiles so as to provide the original materials for appearance and development of thrombi-embolic complications in the long time follow-up. Methods: Twenty-seven cases with prosthetic aortic valve were examined and the blood velocity was measured by using MRI. The diseased heart valves were replaced with two prosthetic valves in 20 cases, and replaced with single prosthetic valve in 7 cases. The axial velocity components were measured at three positions near the valve including half, one, and two diameter downstream in the ascending aorta. Two and three-dimensional surface profile reconstruction were analyzed by using flow analysis software and Matlab 6.5 software. Results: In 16 cases with prosthetic aortic valve replacement with two leaflets prosthetic valves, the velocity profiles downstream of the valve prosthetic reflecting the valve design was nearly three velocity, jets of the two major orifices and the central slit between the two leaflets. In 4 cases with prosthetic aortic valve replace with Sorin two leaflets prosthetic valve, the velocity profiles downstream was nearly two velocity jets of the two major orifices. In 20 cases replaced with two leaflets prosthetic valves, blood velocity profiles were skewed with highest velocities. Seven cases with single leaflet showed single velocity jets of the major orifices at peak systole. Retrograde velocities occurred in part of the lateral orifice regions in 26 cases. Three-dimensional surface profiles downstream of the prosthetic aortic valve reflected the valve design. The blood velocity profiles with prosthetic aortic valve in the one diameter downstream in the ascending aorta clearly showed the valve design. Conclusion: MRI is a non-invasive, direct, and in-vivo method of choice to assess the valvular function and is the

  6. Common Prosthetic Implant Complications in Fixed Restorations.

    Science.gov (United States)

    Link-Bindo, Elyce E; Soltys, James; Donatelli, David; Cavanaugh, Richard

    2016-07-01

    Many clinicians consider implants to be one of the most important innovations in dental care. Even so, over the past 40 years of implant dentistry, complications have been a constant struggle for restorative dentists, surgeons, and patients alike. Implant-related problems can be particularly challenging and frustrating, especially given that an implant is thought to be a "lifetime" solution expected to yield minimal difficulties. This, however, is not necessarily the case with prosthetic restorations. With innovations in implant technology continuing to rapidly advance, maintaining knowledge of all the latest developments can be challenging for clinicians. The purpose of this article is to provide a basic understanding of the treatment, management, and prevention of common prosthetic and technical implant complications seen in the office of a restorative dentist. PMID:27548395

  7. Prosthetic management of an ocular defect

    Directory of Open Access Journals (Sweden)

    Siddesh Kumar Chintal

    2010-01-01

    Full Text Available The disfigurement associated with the loss of an eye can cause significant physical and emotional problems. Various treatment modalities are available, one of which is implants. Although implant has a superior outcome, it may not be advisable in all patients due to economic factors. The present article describes the prosthetic management of an ocular defect with a custom-made ocular prosthesis.

  8. Rapid prototyping technologies in prosthetic dentistry

    OpenAIRE

    YILDIRIM, Arş. Gör. Dt. Melike Pınar; BAYINDIR, Prof. Dr. Funda

    2013-01-01

    Emerged as the concept of rapid prototyping technology, nowadays, is seen as the future of quick and direct production. This technology found applications with metal framework of fixed partial dentures, framework of removable partial dentures, facial protheses and titanium implants in prosthetic dentistry. The virtual image of the restoration is tranferred to the computer and the laser beam is sintered the selected areas on the alloy powders and the restoration is produced layer by layer at s...

  9. Retinal prosthetics, optogenetics, and chemical photoswitches.

    Science.gov (United States)

    Marc, Robert; Pfeiffer, Rebecca; Jones, Bryan

    2014-10-15

    Three technologies have emerged as therapies to restore light sensing to profoundly blind patients suffering from late-stage retinal degenerations: (1) retinal prosthetics, (2) optogenetics, and (3) chemical photoswitches. Prosthetics are the most mature and the only approach in clinical practice. Prosthetic implants require complex surgical intervention and provide only limited visual resolution but can potentially restore navigational ability to many blind patients. Optogenetics uses viral delivery of type 1 opsin genes from prokaryotes or eukaryote algae to restore light responses in survivor neurons. Targeting and expression remain major problems, but are potentially soluble. Importantly, optogenetics could provide the ultimate in high-resolution vision due to the long persistence of gene expression achieved in animal models. Nevertheless, optogenetics remains challenging to implement in human eyes with large volumes, complex disease progression, and physical barriers to viral penetration. Now, a new generation of photochromic ligands or chemical photoswitches (azobenzene-quaternary ammonium derivatives) can be injected into a degenerated mouse eye and, in minutes to hours, activate light responses in neurons. These photoswitches offer the potential for rapidly and reversibly screening the vision restoration expected in an individual patient. Chemical photoswitch variants that persist in the cell membrane could make them a simple therapy of choice, with resolution and sensitivity equivalent to optogenetics approaches. A major complexity in treating retinal degenerations is retinal remodeling: pathologic network rewiring, molecular reprogramming, and cell death that compromise signaling in the surviving retina. Remodeling forces a choice between upstream and downstream targeting, each engaging different benefits and defects. Prosthetics and optogenetics can be implemented in either mode, but the use of chemical photoswitches is currently limited to downstream

  10. Carbon-Based Fibrous EDLC Capacitors and Supercapacitors

    Directory of Open Access Journals (Sweden)

    C. Lekakou

    2011-01-01

    Full Text Available This paper investigates electrochemical double-layer capacitors (EDLCs including two alternative types of carbon-based fibrous electrodes, a carbon fibre woven fabric (CWF and a multiwall carbon nanotube (CNT electrode, as well as hybrid CWF-CNT electrodes. Two types of separator membranes were also considered. An organic gel electrolyte PEO-LiCIO4-EC-THF was used to maintain a high working voltage. The capacitor cells were tested in cyclic voltammetry, charge-discharge, and impedance tests. The best separator was a glass fibre-fine pore filter. The carbon woven fabric electrode and the corresponding supercapacitor exhibited superior performance per unit area, whereas the multiwall carbon nanotube electrode and corresponding supercapacitor demonstrated excellent specific properties. The hybrid CWF-CNT electrodes did not show a combined improved performance due to the lack of carbon nanotube penetration into the carbon fibre fabric.

  11. Coronary artery assessment by multidetector computed tomography in patients with prosthetic heart valves

    NARCIS (Netherlands)

    Habets, Jesse; van den Brink, Renee B. A.; Uijlings, Ruben; Spijkerboer, Anje M.; Mali, Willem P. Th. M.; Chamuleau, Steven A. J.; Budde, Ricardo P. J.

    2012-01-01

    Objectives Patients with prosthetic heart valves may require assessment for coronary artery disease. We assessed whether valve artefacts hamper coronary artery assessment by multidetector CT. Methods ECG-gated or -triggered CT angiograms were selected from our PACS archive based on the presence of p

  12. Piezoresistive Sensors Based on Carbon Nanotube Films

    Institute of Scientific and Technical Information of China (English)

    L(U) Jian-wei; WANG Wan-lu; LIAO Ke-jun; WANG Yong-tian; LIU CHang-lin; Zeng Qing-gao

    2005-01-01

    Piezoresistive effect of carbon nanotube films was investigated by a three-point bending test.Carbon nanotubes were synthesized by hot filament chemical vapor deposition.The experimental results showed that the carbon nanotubes have a striking piezoresistive effect.The relative resistance was changed from 0 to 10.5×10-2 and 3.25×10-2 for doped and undoped films respectively at room temperature when the microstrain under stress from 0 to 500. The gauge factors for doped and undoped carbon nanotube films under 500 microstrain were about 220 and 67 at room temperature, respectively, exceeding that of polycrystalline silicon (30) at 35℃.The origin of the resistance changes in the films may be attributed to a strain-induced change in the band gap for the doped tubes and the defects for the undoped tubes.

  13. Electrochemical insertion of lithium into polyacrylonitrile-based disordered carbons

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Y.; Suh, M.C.; Lee, S.I.; Shim, S.C.; Kwak, J. [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of). Dept. of Chemistry; Lee, H.; Kim, M. [Korea Research Inst. of Standards and Science, Taejon (Korea, Republic of). Div. of Chemistry and Radiation

    1997-12-01

    Electrochemical lithium insertion into polyacrylonitrile (PAN)-based disordered carbons was studied using the techniques of discharge/charge tests, cyclic voltammetry, and {sup 7}Li nuclear magnetic resonance (NMR) spectroscopy. The PAN-based carbons were prepared by vacuum pyrolysis of PAN at 500, 800, and 1,000 C. They showed charge capacities between 254 and 380 mAh/g in the first cycle. {sup 7}Li NMR spectra showed two kinds of lithium insertion sites in the PAN-based carbons: a reversible site where lithium is removed in the subsequent charge process and an irreversible site where lithium remains intact. The NMR results suggest that lithium in fully Li-inserted PAN-based carbons has an ionic character, and reversible site lithium resides between negatively charged carbon layers.

  14. Functional Materials based on Carbon Nanotubes

    OpenAIRE

    Jung, Adrian Thomas

    2007-01-01

    Carbon nanotubes, no matter if they are single-walled or multi-walled, are an integral component in the vastly growing field of nanotechnology. Since their discovery by TEM and the invention of numerous large-scale production techniques, nanotubes are close to making their way into industrial products. Although many properties and modification processes are still under intensive research, the first real-market applications for carbon nanotubes have already been presented. However, if function...

  15. Highly Porous Wood Based Carbon Materials for Supercapacitors

    Science.gov (United States)

    Volperts, A.; Dobele, G.; Zhurinsh, A.; Vervikishko, D.; Shkolnikov, E.; Ozolinsh, J.; Mironova-Ulmane, N.; Sildos, I.

    2015-03-01

    Wood based activated carbons synthesized by two-stage thermocatalytical synthesis with NaOH activator were studied and used as supercapacitor electrodes (sulphuric acid electrolyte). Porous structure and electrochemical properties of carbons vs synthesis conditions were assessed. It was found that there are correlations between carbons synthesis variables, their porosity and supercapacitors functional characteristics. At the temperature 600°C and activator/precursor ratio 1.25 porosity decreased, however energy capacitance of supercapacitor increased calculating on elementary cell mass.

  16. Carbon-Based Fibrous EDLC Capacitors and Supercapacitors

    OpenAIRE

    Lekakou, C.; O. Moudam; Markoulidis, F; Andrews, T.; J. F. Watts; Reed, G.T.

    2011-01-01

    This paper investigates electrochemical double-layer capacitors (EDLCs) including two alternative types of carbon-based fibrous electrodes, a carbon fibre woven fabric (CWF) and a multiwall carbon nanotube (CNT) electrode, as well as hybrid CWF-CNT electrodes. Two types of separator membranes were also considered. An organic gel electrolyte PEO-LiCIO4-EC-THF was used to maintain a high working voltage. The capacitor cells were tested in cyclic voltammetry, charge-discharge, and impedance test...

  17. Toxicology of antimicrobial nanoparticlesfor prosthetic devices

    Directory of Open Access Journals (Sweden)

    Nuñez-Anita RE

    2014-08-01

    Full Text Available Rosa Elvira Nuñez-Anita,1 Laura Susana Acosta-Torres,2 Jorge Vilar-Pineda,2 Juan Carlos Martínez-Espinosa,3 Javier de la Fuente-Hernández, 2 Víctor Manuel Castaño4 1Facultad de Medicina Veterinariay Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Tarìmbaro Municipio de Morelia, Michoacán, México; 2Escuela Nacionalde Estudios Superiores, Universidad Nacional Autónoma de México, Unidad León, Leòn Guanajuato, México; 3Unidad Profesional Interdisciplinaria de Ingenieria Campus Guanajuato, Instituto Politécnico Nacional, Leòn Guanajuato, México; 4Departamento de Materiales Moleculares, Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Campus Juriquilla, Querètaro, México Abstract: Advances in nanotechnology are producing an accelerated proliferation of new nanomaterial composites that are likely to become an important source of engineered health-related products. Nanoparticles with antifungal effects are of great interest in the formulation of microbicidal materials. Fungi are found as innocuous commensals and colonize various habitats in and on humans, especially the skin and mucosa. As growth on surfaces is a natural part of the Candida spp. lifestyle, one can expect that Candida organisms colonize prosthetic devices, such as dentures. Macromolecular systems, due to their properties, allow efficient use of these materials in various fields, including the creation of reinforced nanoparticle polymers with antimicrobial activity. This review briefly summarizes the results of studies conducted during the past decade and especially in the last few years focused on the toxicity of different antimicrobial polymers and factors influencing their activities, as well as the main applications of antimicrobial polymers in dentistry. The present study addresses aspects that are often overlooked in nanotoxicology studies, such as careful time-dependent characterization of agglomeration

  18. Below knee prosthetic socket designs and suspension systems.

    Science.gov (United States)

    Edwards, M L

    2000-08-01

    The prosthetic socket must act as a customized connection between the residual limb's surrounding tissues and the prosthetic components. The socket must be designed to control weight bearing, suspension, and ambulation stability. When making a below-the-knee socket, the prosthetist attempts to maximize loading and minimize displacements, such as vertical, transverse, or rotational. This article discusses the engineering designs or shapes of the two basic forms of below-the-knee prosthetic sockets used today.

  19. Prospects in using carbon-carbon composite materials based on viscose carbon fibers for the space technology needs

    International Nuclear Information System (INIS)

    Due to the unique combination of low density, high mechanical strength under elevated temperatures, high resistance to thermal shock loads and ablation resistance, carbon-carbon composite materials (CCCM) are widely used for manufacturing of highly thermally loaded structural components. The important scientific and technical difficulty is to increase and stabilize CCCM properties, reduce cost and leads to searching for new raw materials and engineering solutions. The article describes the prospects of replacing carbon fiber fills based on PAN-precursors which are traditionally used for producing CCCM by carbon fillers on the basis of viscose raw material; shows the advantages of using viscose-based carbon fibers when forming products of complex shape as well as the possibility of obtaining products with high functional characteristics. The creation of CCCM of layered reinforcement structure, in which carbon fabric layers interleave with layers of discontinuous carbon fibers, enabled to increase the overall density of carbon composites, to ensure sufficiently high level of mechanical characteristics and resistance to ablation

  20. The role of osteoblasts in peri-prosthetic osteolysis.

    LENUS (Irish Health Repository)

    O'Neill, S C

    2013-08-01

    Peri-prosthetic osteolysis and subsequent aseptic loosening is the most common reason for revising total hip replacements. Wear particles originating from the prosthetic components interact with multiple cell types in the peri-prosthetic region resulting in an inflammatory process that ultimately leads to peri-prosthetic bone loss. These cells include macrophages, osteoclasts, osteoblasts and fibroblasts. The majority of research in peri-prosthetic osteolysis has concentrated on the role played by osteoclasts and macrophages. The purpose of this review is to assess the role of the osteoblast in peri-prosthetic osteolysis. In peri-prosthetic osteolysis, wear particles may affect osteoblasts and contribute to the osteolytic process by two mechanisms. First, particles and metallic ions have been shown to inhibit the osteoblast in terms of its ability to secrete mineralised bone matrix, by reducing calcium deposition, alkaline phosphatase activity and its ability to proliferate. Secondly, particles and metallic ions have been shown to stimulate osteoblasts to produce pro inflammatory mediators in vitro. In vivo, these mediators have the potential to attract pro-inflammatory cells to the peri-prosthetic area and stimulate osteoclasts to absorb bone. Further research is needed to fully define the role of the osteoblast in peri-prosthetic osteolysis and to explore its potential role as a therapeutic target in this condition.

  1. An extremely lightweight fingernail worn prosthetic interface device

    Science.gov (United States)

    Yetkin, Oguz; Ahluwalia, Simranjit; Silva, Dinithi; Kasi-Okonye, Isioma; Volker, Rachael; Baptist, Joshua R.; Popa, Dan O.

    2016-05-01

    Upper limb prosthetics are currently operated using several electromyography sensors mounted on an amputee's residual limb. In order for any prosthetic driving interface to be widely adopted, it needs to be responsive, lightweight, and out of the way when not being used. In this paper we discuss the possibility of replacing such electrodes with fingernail optical sensor systems mounted on the sound limb. We present a prototype device that can detect pinch gestures and communicate with the prosthetic system. The device detects the relative position of fingers to each other by measuring light transmitted via tissue. Applications are not limited to prosthetic control, but can be extended to other human-machine interfaces.

  2. Dental prosthetic status and prosthetic need of the institutionalized elderly living in geriatric homes in mangalore: a pilot study.

    Science.gov (United States)

    Shenoy, Rekha P; Hegde, Vijaya

    2011-01-01

    Introduction. To promote oral health among the elderly, we need to know their prosthetic status and prosthetic need. Hence, a survey of prosthetic status and need of elderly inmates of old age homes in Mangalore was done. Materials and Methods. A cross-sectional study was undertaken, and 133 subjects aged 60 years and above were examined (54.9% males and 45.1% females). Results. Eighty-eight percent of those examined were fully edentulous, and only 12% had complete dentures; none of the study subjects had partial dentures. Prosthetic status was significantly associated with gender (P = .024), while prosthetic need and gender were not significantly associated (P = .395). Conclusions. A high unmet need for prosthetic care existed among the institutionalized elderly surveyed.

  3. Carbon pipette-based electrochemical nanosampler.

    Science.gov (United States)

    Yu, Yun; Noël, Jean-Marc; Mirkin, Michael V; Gao, Yang; Mashtalir, Olha; Friedman, Gary; Gogotsi, Yury

    2014-04-01

    Sampling ultrasmall volumes of liquids for analysis is essential in a number of fields from cell biology to microfluidics to nanotechnology and electrochemical energy storage. In this article, we demonstrate the possibility of using nanometer-sized quartz pipettes with a layer of carbon deposited on the inner wall for sampling attoliter-to-picoliter volumes of fluids and determining redox species by voltammetry and coulometry. Very fast mass-transport inside the carbon-coated nanocavity allows for rapid exhaustive electrolysis of the sampled material. By using a carbon pipette as the tip in the scanning electrochemical microscope (SECM), it can be precisely positioned at the sampling location. The developed device is potentially useful for solution sampling from biological cells, micropores, and other microscopic objects. PMID:24655227

  4. Three-dimensional carbon nanotube based photovoltaics

    Science.gov (United States)

    Flicker, Jack

    2011-12-01

    Photovoltaic (PV) cells with a three dimensional (3D) morphology are an exciting new research thrust with promise to create cheaper, more efficient solar cells. This work introduces a new type of 3D PV device based on carbon nanotube (CNT) arrays. These arrays are paired with the thin film heterojunction, CdTe/CdS, to form a complete 3D carbon nanotube PV device (3DCNTPV). Marriage of a complicated 3D structure with production methods traditionally used for planar CdTe solar cell is challenging. This work examines the problems associated with processing these types of cells and systematically alters production methods of the semiconductor layers and electrodes to increase the short circuit current (Isc), eliminate parasitic shunts, and increase the open circuit voltage (Voc). The main benefit of 3D solar cell is the ability to utilize multiple photon interactions with the solar cell surface. The three dimensionality allows photons to interact multiple times with the photoactive material, which increases the absorption and the overall power output over what is possible with a two dimensional (2D) morphology. To quantify the increased power output arising from these multiple photon interactions, a new absorption efficiency term, eta3D, is introduced. The theoretical basis behind this new term and how it relates to the absorption efficiency of a planar cell, eta 2D, is derived. A unique model for the average number of multiple photon impingements, Gamma, is proposed based on three categories of 3D morphology: an infinite trench, an enclosed box, and an array of towers. The derivation of eta3D and Gamma for these 3D PV devices gives a complete picture of the enhanced power output over 2D cells based on CNT array height, pitch, radius, and shape. This theory is validated by monte carlo simulations and experiment. This new type of 3D PV devices has been shown to work experimentally. The first 3DCNTPV cells created posses Isc values of 0.085 to 17.872mA/cm2 and Voc values

  5. Preparation of perlite-based carbon dioxide absorbent.

    Science.gov (United States)

    He, H; Wu, L; Zhu, J; Yu, B

    1994-02-01

    A new highly efficient carbon dioxide absorbent consisting of sodium hydroxide, expanded perlite and acid-base indicator was prepared. The absorption efficiency, absorption capacity, flow resistance and color indication for the absorbent were tested and compared with some commercial products. The absorbent can reduce the carbon dioxide content in gases to 3.3 ppb (v/v) and absorbs not less than 35% of its weight of carbon dioxide. Besides its large capacity and sharp color indication, the absorbent has an outstanding advantage of small flow resistance in comparison with other commercial carbon dioxide absorbents. Applications in gas analysis and purification were also investigated.

  6. Carbon Dot Based Sensing of Dopamine and Ascorbic Acid

    OpenAIRE

    Upama Baruah; Neelam Gogoi; Achyut Konwar; Manash Jyoti Deka; Devasish Chowdhury; Gitanjali Majumdar

    2014-01-01

    We demonstrate carbon dot based sensor of catecholamine, namely, dopamine and ascorbic acid. Carbon dots (CDs) were prepared from a green source: commercially available Assam tea. The carbon dots prepared from tea had particle sizes of ∼0.8 nm and are fluorescent. Fluorescence of the carbon dots was found to be quenched in the presence of dopamine and ascorbic acid with greater sensitivity for dopamine. The minimum detectable limits were determined to be 33 μM and 98 μM for dopamine and ascor...

  7. A five-fingered underactuated prosthetic hand: hardware and its control scheme

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jing-dong; JIANG Li; CAI He-gao; LIU hong

    2008-01-01

    A five-fingered underactuated prosthetic hand controlled by surface EMG (electromyographic) sig-nals is presented in this paper. The prosthetic hand was designed with simplicity, lightweight and dexterity on the requirement of anthropomorphic hands. Underactuated self-adaptive theory was adopted to decrease the number of motors and weight. The control part of the prosthetic hand was based on a surface EMG motion pat-tern classifier which combines LM-based (Levenberg-Marquardt) neural network with the parametric AR ( au-toregressive) model. This motion pattern classifier can successfully identify the flexions of the thumb, the index finger and the middle finger by measuring the surface EMG signals through two electrodes mounted on the flexor digitorum profundus and flexor pollicis longus. Furthermore, via continuously controlling a single finger' s mo-tion, the five-fingered underactuated prosthetic hand can achieve more prehensile postures such as power grasp,centralized grip, fingertip grasp, cylindrical grasp, etc. The experimental results show that the classifier has a great potential application to the control of bionic man-machine systems because of its fast learning speed, high recognition capability and strong robustness.

  8. Deformation Resistance Effect of PAN-based Carbon Fibers

    Institute of Scientific and Technical Information of China (English)

    ZHENG Lixia; LI Zhuoqiu; SONG Xianhui; LU Yong

    2009-01-01

    The deformation resistance effect of polyacrylonitrile(PAN)-based carbon fibers was investigated,and the variatipn law of electrical resistivity under tensile stress was analyzed.The results show that the gauge factor(fractional change in resistance per unit strain)of PAN-based carbon fibers is 1.38,which is lower than that of the commonly-used resistance strain gauge.These may due to that the electrical resistivity of carbon fibers decreases under tensile stress.In addition when the carbon fibers are stretched,the change of its resistance is caused by fiber physical dimension and the change of electric resistivity,and mainly caused by the change of physical dimension.The mechanical properties of carbon fiber monofilament were also measured.

  9. Finite Element Analysis of Fracture Toughness of Pyrolytic Carbon in Prosthetic Heart Valve%人工心瓣热解炭断裂韧性有限元分析

    Institute of Scientific and Technical Information of China (English)

    张建辉; 邢兴

    2012-01-01

    This article used ANSYS to conduct simulation analysis of compact tension and 3 points bending test for the isotropic pyrolytic carbon and pyrolytic carbon-coated graphite composite material used in heart valve prosthesis, calculated the plane strain fracture toughness KIC and compared the calculated results with the results of related experiments, then analyzed the effectiveness of the method that used ANSYS to calculate KIC as well as the influence of the thickness ratio of the coating and substrate and crack tip radius for the KIC of pyrolytic carbon-coated graphite composite material. Results showed that the KIC of the pure pyrolytic carbon and graphite material were respectively 1. 176 MPa √m and 1. 415 MPa √m, which were close to the results of related experiments, verifying the accuracy of using ANSYS to calculate KIC ; the KIC of composite material of pyrolytic carbon-coated graphite reduced with the increase of thickness ratio for the coating and substrate. The fracture toughness of composite material was better than that of pure pyrolytic carbon or graphite composite material when the thickness ratio of coating and substrate was on the low side; pyrolitic carbon-coated graphite had a limit notch root radius p0, which was about 5 μm, when the notch root radius p >p0, the measured value of KIC was proportional to p1/2 , and when p < po, the measured value of KIC was in line with the value of samples with sharp crack.%利用有限元分析软件ANSYS,对人工心瓣各向同性热解炭和热解炭包覆石墨复合材料进行紧凑拉伸以及三点弯曲实验仿真分析,计算材料的平面应变断裂韧性KIC,并将计算结果与相关实验结果进行对比,分析利用ANSYS计算KIC方法的有效性,以及涂层与基体厚度比、裂纹尖端半径对热解炭包覆石墨复合材料KIC值的影响.结果表明,纯热解炭和石墨材料的ANSYS计算KIC值分别为1.176 MPa√m以及1.415 MPa√m,与相关实验结果接近,验证

  10. High-Conductance Thermal Interfaces Based on Carbon Nanotubes Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a novel thermal interface material (TIM) that is based on an array of vertical carbon nanotubes (CNTs) for high heat flux applications. For...

  11. Recent advances in carbon-based dots for electroanalysis.

    Science.gov (United States)

    Yulong, Ying; Xinsheng, Peng

    2016-04-25

    Carbon-based dots represent a new type of quantum dot with unique and well-defined properties owing to their quantum confinement and edge effects, which are widely employed in sensing, light-emitting diodes, nanomedicine, photocatalysis, electrocatalysis, bioimaging, etc. In this review, we update the latest research results of carbon-based dots in this rapidly evolving field of electroanalysis, place emphases on their applications as sensors and give future perspectives for developing more smart sensors.

  12. A geometrical optimization of a magneto-rheological rotary brake in a prosthetic knee

    Science.gov (United States)

    Gudmundsson, K. H.; Jonsdottir, F.; Thorsteinsson, F.

    2010-03-01

    Magneto-rheological (MR) fluids have been successfully introduced to prosthetic devices. One such device is a biomechanical prosthetic knee that uses MR fluids to actively control its rotary stiffness. The brake is rotational, utilizing the MR fluid in shear mode. In this study, the geometrical design of the MR brake is addressed. This includes the design of the magnetic circuit and the geometry of the fluid chamber. Mathematical models are presented that describe the rotary torque of the brake. A novel perfluorinated polyether (PFPE)-based MR fluid is introduced, whose properties are tailored for the prosthetic knee. On-state and off-state rheological measurements of the MR fluid are presented. The finite element method is used to evaluate the magnetic flux density in the MR fluid. The design is formulated as an optimization problem, aiming to maximize the braking torque. A parametric study is carried out for several design parameters. Subsequently, a multi-objective optimization problem is defined that considers three design objectives: the field-induced braking torque, the off-state rotary stiffness and the weight of the brake. Trade-offs between the three design objectives are investigated which provides a basis for informed design decisions on furthering the success of the MR prosthetic knee.

  13. Carbon Nanotube-Based Permeable Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Holt, J K; Park, H G; Bakajin, O; Noy, A; Huser, T; Eaglesham, D

    2004-04-06

    A membrane of multiwalled carbon nanotubes embedded in a silicon nitride matrix was fabricated for use in studying fluid mechanics on the nanometer scale. Characterization by fluorescent tracer diffusion and scanning electron microscopy suggests that the membrane is void-free near the silicon substrate on which it rests, implying that the hollow core of the nanotube is the only conduction path for molecular transport. Assuming Knudsen diffusion through this nanotube membrane, a maximum helium transport rate (for a pressure drop of 1 atm) of 0.25 cc/sec is predicted. Helium flow measurements of a nanoporous silicon nitride membrane, fabricated by sacrificial removal of carbon, give a flow rate greater than 1x10{sup -6} cc/sec. For viscous, laminar flow conditions, water is estimated to flow across the nanotube membrane (under a 1 atm pressure drop) at up to 2.8x10{sup -5} cc/sec (1.7 {micro}L/min).

  14. Carbon Nanotube Tower-Based Supercapacitor

    Science.gov (United States)

    Meyyappan, Meyya (Inventor)

    2012-01-01

    A supercapacitor system, including (i) first and second, spaced apart planar collectors, (ii) first and second arrays of multi-wall carbon nanotube (MWCNT) towers or single wall carbon nanotube (SWCNT) towers, serving as electrodes, that extend between the first and second collectors where the nanotube towers are grown directly on the collector surfaces without deposition of a catalyst and without deposition of a binder material on the collector surfaces, and (iii) a porous separator module having a transverse area that is substantially the same as the transverse area of at least one electrode, where (iv) at least one nanotube tower is functionalized to permit or encourage the tower to behave as a hydrophilic structure, with increased surface wettability.

  15. Principles of obstacle avoidance with a transfemoral prosthetic limb

    NARCIS (Netherlands)

    van Keeken, Helco G.; Vrieling, Aline H.; Hof, At L.; Postema, Klaas; Otten, Bert

    2012-01-01

    In this study, conditions that enable a prosthetic knee flexion strategy in transfemoral amputee subjects during obstacle avoidance were investigated. This study explored the hip torque principle and the static ground principle as object avoidance strategies. A prosthetic limb simulator device was u

  16. 21 CFR 870.3935 - Prosthetic heart valve holder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prosthetic heart valve holder. 870.3935 Section 870.3935 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... heart valve holder. (a) Identification. A prosthetic heart valve holder is a device used to hold...

  17. Stiffness and hysteresis properties of some prosthetic feet

    NARCIS (Netherlands)

    Jaarsveld, van H.W.L.; Grootenboer, H.J.; Vries, de J.; Koopman, H.F.J.M.

    1990-01-01

    A prosthetic foot is an important element of a prosthesis, although it is not always fully recognized that the properties of the foot, along with the prosthetic knee joint and the socket, are in part responsible for the stability and metabolic energy cost during walking. The stiffness and the hyst

  18. Raoultella ornithinolytica: An unusual pathogen for prosthetic joint infection

    Directory of Open Access Journals (Sweden)

    Piseth Seng

    2016-01-01

    Full Text Available We herein report the first case of a prosthetic joint infection caused by Raoultella ornithinolytica in an immunocompetent patient. The clinical outcome was favorable after a two-stage prosthetic exchange and a six-month course of antimicrobial therapy.

  19. Prosthetic Rehabilitation in Children: An Alternative Clinical Technique

    Directory of Open Access Journals (Sweden)

    Nádia Carolina Teixeira Marques

    2013-01-01

    Full Text Available Complete and partial removable dentures have been used successfully in numerous patients with oligodontia and/or anodontia. However, there is little information in the literature regarding the principles and guidelines to prosthetic rehabilitation for growing children. This case report describes the management of a young child with oligodontia as well as the treatment planning and the prosthetic rehabilitation technique.

  20. Room temperature ferromagnetism in a phthalocyanine based carbon material

    Energy Technology Data Exchange (ETDEWEB)

    Honda, Z., E-mail: honda@fms.saitama-u.ac.jp; Sato, K.; Sakai, M.; Fukuda, T.; Kamata, N. [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Hagiwara, M.; Kida, T. [KYOKUGEN (Center for Quantum Science and Technology under Extreme Conditions), Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)

    2014-02-07

    We report on a simple method to fabricate a magnetic carbon material that contains nitrogen-coordinated transition metals and has a large magnetic moment. Highly chlorinated iron phthalocyanine was used as building blocks and potassium as a coupling reagent to uniformly disperse nitrogen-coordinated iron atoms on the phthalocyanine based carbon material. The iron phthalocyanine based carbon material exhibits ferromagnetic properties at room temperature and the ferromagnetic phase transition occurs at T{sub c} = 490 ± 10 K. Transmission electron microscopy observation, X-ray diffraction analysis, and the temperature dependence of magnetization suggest that the phthalocyanine molecules form three-dimensional random networks in the iron phthalocyanine based carbon material.

  1. Carbon nanotube based pressure sensor for flexible electronics

    Energy Technology Data Exchange (ETDEWEB)

    So, Hye-Mi [Department of Nano Mechanics, Nanomechanical Systems Research Division, Korea Institute of Machinery and Materials, Daejeon 305-343 (Korea, Republic of); Sim, Jin Woo [Advanced Nano Technology Ltd., Seoul 132-710 (Korea, Republic of); Kwon, Jinhyeong [Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of); Yun, Jongju; Baik, Seunghyun [SKKU Advanced Institute of Nanotechnology (SAINT), Department of Energy Science and School of Mechanical Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Chang, Won Seok, E-mail: paul@kimm.re.kr [Department of Nano Mechanics, Nanomechanical Systems Research Division, Korea Institute of Machinery and Materials, Daejeon 305-343 (Korea, Republic of)

    2013-12-15

    Highlights: • The electromechanical change of vertically aligned carbon nanotubes. • Fabrication of CNT field-effect transistor on flexible substrate. • CNT based FET integrated active pressure sensor. • The integrated device yields an increase in the source-drain current under pressure. - Abstract: A pressure sensor was developed based on an arrangement of vertically aligned carbon nanotubes (VACNTs) supported by a polydimethylsiloxane (PDMS) matrix. The VACNTs embedded in the PDMS matrix were structurally flexible and provided repeated sensing operation due to the high elasticities of both the polymer and the carbon nanotubes (CNTs). The conductance increased in the presence of a loading pressure, which compressed the material and induced contact between neighboring CNTs, thereby producing a dense current path and better CNT/metal contacts. To achieve flexible functional electronics, VACNTs based pressure sensor was integrated with field-effect transistor, which is fabricated using sprayed semiconducting carbon nanotubes on plastic substrate.

  2. Influence of rectification procedure on the counter-torque force of prosthetic screws of implant-retained frameworks

    Directory of Open Access Journals (Sweden)

    Mauro Antonio de Arruda Nobilo

    2008-01-01

    Full Text Available Objective: To evaluate the counter-force of prosthetic screws before and after the rectification procedure of the seating base of prosthetic framework screws. Methods: With a metal matrix containing three replicas of conical abutments (Micro-Unit; Conexão placed at 10 mm from center to center, ten multiple cast structures were made of a titanium monoblock. The multiple cast structures were fastened onto the metal matrix abutments with a torque of 10 NCm. The screwing sequence was performed from the central pillar towards the distal ones. The force (Ncmnecessary for counter-torque was evaluated using a digital torque meter (TQ3000; Lutron, Taipei, Taiwan. This procedure was carried out before and after rectification of the seating base of the prosthetic screws, by means of a manual rectifier tip (Conexão Sistemas de Prótese, São Paulo, Brazil. The mean counter-torque values were calculated for each structure before and after rectification. The t-Test for paired samples was used to compare the evaluated situations. Results: Significant difference was observed between the mean counter-torque force value of the prosthetic screws before (5.78±1.03Ncm and after (7.06±0.62Ncm the rectification procedures (p<0.01. Conclusion: The rectifying process of the seating base significantly increased the values of force required to counter-torque the prosthetic screws of cast implant-retained multiple frameworks.

  3. Prosthetic knee design by simulation

    Energy Technology Data Exchange (ETDEWEB)

    Hollerbach, K; Hollister, A

    1999-07-30

    Although 150,000 total knee replacement surgeries are performed annually in North America, current designs of knee prostheses have mechanical problems that include a limited range of motion, abnormal gait patterns, patellofemoral joint dysfunction, implant loosening or subsidence, and excessive wear. These problems fall into three categories: failure to reproduce normal joint kinematics, which results in altered limb function; bone-implant interface failure; and material failure. Modern computer technology can be used to design, prototype, and test new total knee implants. The design team uses the full range of CAD-CAM to design and produce implant prototypes for mechanical and clinical testing. Closer approximation of natural knee kinematics and kinetics is essential for improved patient function and diminished implant loads. Current knee replacement designs are based on 19th Century theories that the knee moves about a variable axis of rotation. Recent research has shown, however, that knee motion occurs about two fixed, offset axes of rotation. These aces are not perpendicular to the long axes of the bones or to each other, and the axes do not intersect. Bearing surfaces of mechanisms that move about axes of rotation are surfaces of revolution of those axes which advanced CAD technology can produce. Solids with surfaces of revolution for the two axes of rotation for the knee have been made using an HP9000 workstation and Structural Ideas Master Series CAD software at ArthroMotion. The implant's CAD model should closely replicate movements of the normal knee. The knee model will have a range of flexion-extension (FE) from -5 to 120 degrees. Movements include varus, valgus, internal and external rotation, as well as flexion and extension. The patellofemoral joint is aligned perpendicular to the FE axis and replicates the natural joint more closely than those of existing prostheses. The bearing surfaces will be more congruent than current designs and should

  4. Effect of Anodization on the Graphitization of PANbased Carbon Fibers of PAN-based Carbon Fibers

    Institute of Scientific and Technical Information of China (English)

    HE Dongmei; YAO Yinghua; XU Shihai; CAI Qingyun

    2011-01-01

    One-step pretreatment,anodization,is used to activate the polyacrylonitrile (PAN)-based carbon fibers instead of the routine two-step pretreatment,sensitization with SnCl2 and activation with PdCl2 The effect of the anodization pretreatment on the graphitization of PAN-based carbon fibers is investigated as a function of Ni-P catalyst.The PAN-based carbon fibers are anodized in H3PO4 electrolyte resulting in the formation of active sites,which thereby facilitates the following electroless Ni-P coating.Carbon fibers in the presence and absence of Ni-P coatings are heat treated and the structural changes are characterized by X-ray diffraction and Raman spectroscopy,both of which indicate that the graphitization of PAN-based carbon fibers are accelerated by both the anodization treatment and the catalysts Ni-E Using the anodized carbon fibers,the routine two-step pretreatment,sensitization and activation,is not needed.

  5. Prosthetic heart valves: Objective Performance Criteria versus randomized clinical trial.

    Science.gov (United States)

    Grunkemeier, Gary L; Jin, Ruyun; Starr, Albert

    2006-09-01

    The current Food and Drug Administration (FDA) heart valve guidance document uses an objective performance criteria (OPC) methodology to evaluate the clinical performance of prosthetic heart valves. OPC are essentially historical controls, but they have turned out to be an adequate, and perhaps optimal, study design in this situation. Heart valves have a simple open-and-close mechanism, device effectiveness is easy to document, and the common complications (thromboembolism, thrombosis, bleeding, leak, and infection) are well known and easily detected. Thus, randomized clinical trials (RCTs) have not been deemed necessary for the regulatory approval of prosthetic heart valves. The OPC are derived from the average complication rates of all approved heart valves. Studies based on OPC have been shown to work well; many different valve models have gained FDA market approval based on this methodology. Although heart valve RCTs are not required by the FDA, they have been done to compare valves or treatment regimens after approval. Recently, the Artificial Valve Endocarditis Reduction Trial (AVERT) was designed to compare a new Silzone sewing ring, designed to reduce infection, with the Standard sewing ring on a St. Jude Medical heart valve. This was the largest heart valve RCT ever proposed (4,400 valve patients, followed for as long as 4 years), but it was stopped prematurely because of a high leak rate associated with the Silzone valve. Examining the results showed that a much smaller, OPC-based study with 800 patient-years would have been sufficient to disclose this complication of the Silzone valve. PMID:16928482

  6. Methane Adsorption Study Using Activated Carbon Fiber and Coal Based Activated Carbon

    Institute of Scientific and Technical Information of China (English)

    Guo Deyong; Li Fei; Liu Wenge

    2013-01-01

    Inlfuence of ammonium salt treatment and alkali treatment of the coal based activated carbon (AC) and activated carbon ifber (ACF) adsorbents on methane adsorption capacity was studied via high-pressure adsorption experiment. Sur-face functional groups and pore structure of two types of adsorbents were characterized by the application of infrared ab-sorption spectroscopy (IR) and low temperature liquid nitrogen adsorption method. The results show that both ammonium salt treatment and alkali treatment have obvious effect on changing BET, pore volume as well as pore size distribution of adsorbents; and methane adsorption capacity of the activated carbon ifber is the maximum after the ammonium salt treatment.

  7. Patient-adapted treatment for prosthetic hip joint infection.

    Science.gov (United States)

    Baker, Richard P; Furustrand Tafin, Ulrika; Borens, Olivier

    2015-01-01

    Hip joint replacement is 1 of the most successful surgical procedures of the last century and the number of replacements implanted is steadily growing. An infected hip arthroplasty is a disaster, it leads to patient suffering, surgeon's frustration and significant costs to the health system. The treatment of an infected hip replacement is challenging, healing rates can be low, functional results poor with decreased patient satisfaction. However, if a patient-adapted treatment of infected hip joints is used a success rate of above 90% can be obtained.Patient-adapted treatment is based on 5 important concepts: teamwork; understanding the biofilm; diagnostic accuracy; correct definition and classification of PJI; and patient-tailored treatment.This review presents a patient-adapted treatment strategy to prosthetic hip infection. It incorporates the best aspects of the single and staged surgical strategies and promotes the short interval philosophy for the 2-stage approach. PMID:26044528

  8. Epoxy based photoresist/carbon nanoparticle composites

    DEFF Research Database (Denmark)

    Lillemose, Michael; Gammelgaard, Lauge; Richter, Jacob;

    2008-01-01

    We have fabricated composites of SU-8 polymer and three different types of carbon nanoparticles (NPs) using ultrasonic mixing. Structures of composite thin films have been patterned on a characterization chip with standard UV photolithography. Using a four-point bending probe, a well defined stress...... is applied to the composite thin film and we have demonstrated that the composites are piezoresistive. Stable gauge factors of 5-9 have been measured, but we have also observed piezoresistive responses with gauge factors as high as 50. As SU-8 is much softer than silicon and the gauge factor of the composite...

  9. Surgical and prosthetic treatment for microphthalmia syndromes.

    Science.gov (United States)

    Wavreille, O; François Fiquet, C; Abdelwahab, O; Laumonier, E; Wolber, A; Guerreschi, P; Pellerin, P

    2013-03-01

    Our aim was to evaluate the long-term outcomes of prosthetic treatment and orbital expansion in the management of microphthalmia syndromes. We did a retrospective single-centre study of all cases of microphthalmia treated between 1989 and 2010. The patients were divided into three groups: isolated microphthalmia, microphthalmia associated with micro-orbitism, and complex microphthalmia syndrome. To evaluate the results a score was computed for each patient by assessing the length of the palpebral fissure, the depth of the conjunctival fornix, and local complications together with an evaluation of the satisfaction of patients and their families. Forty-four children were included (27 boys and 17 girls). Twenty-seven had unilateral microphthalmia (61%) and 17 bilateral microphthalmia (39%). Twelve patients were lost to follow up. The mean duration of follow-up was 12 years (range 4-21). Management involved an ocular conformer in only 31 patients (71%). The treatment was deemed satisfactory in all except 10 children. Surgical treatment with orbital expansion permitted good symmetry of the orbital cavities with a final mean difference of 9% (range 3-17) compared with the initial 16.8% (range 13.6-20.3). The prosthetic treatment gives satisfactory results. Despite limited indications and difficult follow-up, our experience emphasises the value of surgical treatment for severe micro-orbitism.

  10. Nano-yarn carbon nanotube fiber based enzymatic glucose biosensor

    OpenAIRE

    Zhu, Z.; Song, W.; Burugapalli, K; Moussy, F; Li, Y-L; Zhong, X-H

    2010-01-01

    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2010 IOP Publishing Ltd. A novel brush-like electrode based on carbon nanotube (CNT) nano-yarn fiber has been designed for electrochemical biosensor applications and its efficacy as an enzymatic glucose biosensor demonstrated. The CNT nano-yarn fiber was spun directly from a chemical-vapor-deposition (CVD) gas flow reaction using a mixture of ethanol and acetone as the carbon...

  11. Carbon Nanotubes Based Glucose Needle-type Biosensor

    OpenAIRE

    Hong Li; Yongquan Li; Minghao Sim; Wenjun Guan; Jinyan Jia

    2008-01-01

    A novel needle-type biosensor based on carbon nanotubes is reported. The biosensor was prepared by packing a mixture of multi-wall carbon nanotubes (MWCNTs), graphite powder and glucose oxidase (Gox) freeze-dried powder into a glass capillary of 0.5 mm inner diameter. The resulting amperometric biosensor was characterized electrochemically using amperometry in the presence of hydrogen peroxide and in the presence of glucose. The glucose biosensor sensitivity was influenced by the glucose oxid...

  12. COMMERCIAL VIABILITY ANALYSIS OF LIGNIN BASED CARBON FIBRE

    OpenAIRE

    Michael Chien-Wei Chen

    2014-01-01

    Lignin is a rich renewable source of aromatic compounds. As a potentialpetroleum feedstock replacement, lignin can reduce environmental impacts such ascarbon emission. Due to its complex chemical structure, lignin is currently underutilized.Exploiting lignin as a precursor for carbon fibre adds high economic value to lignin andencourages further development in lignin extraction technology. This report includes apreliminary cost analysis and identifies the key aspects of lignin-based carbon fi...

  13. Carbon nanotube-based coatings on titanium

    Indian Academy of Sciences (India)

    Elzbieta Dlugon; Wojciech Simka; Aneta Fraczek-Szczypta; Wiktor Niemiec; Jaroslaw Markowski; Marzena Szymanska; Marta Blazewicz

    2015-09-01

    This paper reports results of the modification of titanium surface with multiwalled carbon nanotubes (CNTs). The Ti samples were covered with CNTs via electrophoretic deposition (EPD) process. Prior to EPD process, CNTs were functionalized by chemical treatment. Mechanical, electrochemical and biological properties of CNT-covered Ti samples were studied and compared to those obtained for unmodified titanium surface. Atomic force microscopy was used to investigate the surface topography. To determine micromechanical characteristics of CNT-covered metallic samples indentation tests were conducted. Throughout electrochemical studies were performed in order to characterize the impact of the coating on the corrosion of titanium substrate. In vitro experiments were conducted using the human osteoblast NHOst cell line. CNT layers shielded titanium from corrosion gave the surface-enhanced biointegrative properties. Cells proliferated better on the modified surface in comparison to unmodified titanium. The deposited layer enhanced cell adhesion and spreading as compared to titanium sample.

  14. Carbon-Based Compounds and Exobiology

    Science.gov (United States)

    Kerridge, John; DesMarais, David; Khanna, R. K.; Mancinelli, Rocco; McDonald, Gene; diBrozollo, Fillipo Radicati; Wdowiak, Tom

    1996-01-01

    The Committee for Planetary and Lunar Explorations (COMPLEX) posed questions related to exobiological exploration of Mars and the possibility of a population of carbonaceous materials in cometary nuclei to be addressed by future space missions. The scientific objectives for such missions are translated into a series of measurements and/or observations to be performed by Martian landers. These are: (1) A detailed mineralogical, chemical, and textural assessment of rock diversity at a landing site; (2) Chemical characterization of the materials at a local site; (3) Abundance of Hydrogen at any accessible sites; (4) Identification of specific minerals that would be diagnostic of aqueous processes; (5) Textual examination of lithologies thought to be formed by aqueous activity; (6) Search for minerals that might have been produced as a result of biological processes; (7) Mapping the distribution, in three dimensions, of the oxidant(s) identified on the Martian surface by the Viking mission; (8) Definition of the local chemical environment; (9) Determination of stable-isotopic ratios for the biogenic elements in surface mineral deposits; (10) Quantitative analysis of organic (non-carbonate) carbon; (11) Elemental and isotopic composition of bulk organic material; (12) Search for specific organic compounds that would yield information about synthetic mechanisms, in the case of prebiotic evolution, and about possible bio-markers, in the case of extinct or extant life; (13) and Coring, sampling, and detection of entrained gases and cosmic-ray induced reaction products at the polar ice cap. A discussion of measurements and/or observations required for cometary landers is included as well.

  15. Carbon nanotubes and carbon onions for modification of styrene-acrylate copolymer based nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Merijs-Meri, Remo; Zicans, Janis; Ivanova, Tatjana; Bitenieks, Juris [Institute of Polymer Materials, Riga Technical University, Azenes street 14/24, LV-1048, Riga (Latvia); Kuzhir, Polina; Maksimenko, Sergey [Institute of Nuclear Problems, Belarus State University, Bobruiskaya str. 11, 220030, Minsk (Belarus); Kuznetsov, Vladimir; Moseenkov, Sergey [Boreskov Institute of Catalyst Siberian branch of RAS, pr. Lavrentieva 5, 630090, Novosibirsk (Russian Federation)

    2014-05-15

    Styrene acrylate polymer (SAC) nanocomposites with various carbon nanofillers (multiwalled carbon nanotubes MWCNTs and onion like carbon OLC) are manufactured by means of latex based routes. Concentration of the carbon nanofillers is changed in a broad interval starting from 0.01 up to 10 wt. %. Elastic, dielectric and electromagnetic properties of SAC nanocomposites are investigated. Elastic modulus, electrical conductivity and electromagnetic radiation absorption of the investigated SAC nanocomposites increase along with rising nanofiller content. The effect of the addition of anisometric MWCNTs on the elastic properties of the composite is higher than in the case of the addition of OLC. Higher electrical conductivity of the OLC containing nanocomposites is explained with the fact that reasonable agglomeration of the nanofiller can promote the development of electrically conductive network. Efficiency of the absorption of electromagnetic radiation depends on the development of conductive network within the SAC matrix.

  16. Mesoporous Carbon-based Materials for Alternative Energy Applications

    Science.gov (United States)

    Cross, Kimberly Michelle

    Increasing concerns for the escalating issues activated by the effect of carbon dioxide emissions on the global climate from extensive use of fossil fuels and the limited amount of fossil resources has led to an in-depth search for alternative energy systems, primarily based on nuclear or renewable energy sources. Recent innovations in the production of more efficient devices for energy harvesting, storage, and conversion are based on the incorporation of nanostructured materials into electrochemical systems. The aforementioned nano-electrochemical energy systems hold particular promise for alternative energy transportation related technologies including fuel cells, hydrogen storage, and electrochemical supercapacitors. In each of these devices, nanostructured materials can be used to increase the surface area where the critical chemical reactions occur within the same volume and mass, thereby increasing the energy density, power density, electrical efficiency, and physical robustness of the system. Durable corrosion resistant carbon support materials for fuel cells have been designed by adding conductive low cost carbon materials with chemically robust ceramic materials. Since a strict control of the pore size is mandatory to optimize properties for improved performance, chemical activation agents have been utilized as porogens to tune surface areas, pore size distributions, and composition of carbon-based mesoporous materials. Through the use of evaporative self-assembly methods, both randomly disordered and surfactant-templated, ordered carbon-silica nanocomposites have been synthesized with controlled surface area, pore volume, and pore size ranging from 50-800 m2/g, 0.025-0.75 cm3/g, and 2-10 nm, respectively. Multi-walled carbon nanotubes (MWNTs) ranging from 0.05-1.0 wt. % were added to the aforementioned carbon-silica nanocomposites, which provided an additional increase in surface area and improved conductivity. Initially, a conductivity value of 0.0667 S

  17. Predicting prosthetic prescription after major lower-limb amputation

    Directory of Open Access Journals (Sweden)

    Linda Resnik, PT, PhD, OCS

    2015-09-01

    Full Text Available We describe prosthetic limb prescription in the first year following lower-limb amputation and examine the relationship between amputation level, geographic region, and prosthetic prescription. We analyzed 2005 to 2010 Department of Veterans Affairs (VA Inpatient and Medical Encounters SAS data sets, Vital Status death data, and National Prosthetic Patient Database data for 9,994 Veterans who underwent lower-limb amputation at a VA hospital. Descriptive statistics and bivariates were examined. Cox proportional hazard models identified factors associated with prosthetic prescription. Analyses showed that amputation level was associated with prosthetic prescription. The hazard ratios (HRs were 1.41 for ankle amputation and 0.46 for transfemoral amputation compared with transtibial amputation. HRs for geographic region were Northeast = 1.49, Upper Midwest = 1.26, and West = 1.39 compared with the South (p < 0.001. African American race, longer length of hospital stay, older age, congestive heart failure, paralysis, other neurological disease, renal failure, and admission from a nursing facility were negatively associated with prosthetic prescription. Being married was positively associated. After adjusting for patient characteristics, people with ankle amputation were most likely to be prescribed a prosthesis and people with transfemoral amputation were least likely. Geographic variation in prosthetic prescription exists in the VA and further research is needed to explain why.

  18. Predicting prosthetic prescription after major lower-limb amputation.

    Science.gov (United States)

    Resnik, Linda; Borgia, Matthew

    2015-01-01

    We describe prosthetic limb prescription in the first year following lower-limb amputation and examine the relationship between amputation level, geographic region, and prosthetic prescription. We analyzed 2005 to 2010 Department of Veterans Affairs (VA) Inpatient and Medical Encounters SAS data sets, Vital Status death data, and National Prosthetic Patient Database data for 9,994 Veterans who underwent lower-limb amputation at a VA hospital. Descriptive statistics and bivariates were examined. Cox proportional hazard models identified factors associated with prosthetic prescription. Analyses showed that amputation level was associated with prosthetic prescription. The hazard ratios (HRs) were 1.41 for ankle amputation and 0.46 for transfemoral amputation compared with transtibial amputation. HRs for geographic region were Northeast = 1.49, Upper Midwest = 1.26, and West = 1.39 compared with the South (p length of hospital stay, older age, congestive heart failure, paralysis, other neurological disease, renal failure, and admission from a nursing facility were negatively associated with prosthetic prescription. Being married was positively associated. After adjusting for patient characteristics, people with ankle amputation were most likely to be prescribed a prosthesis and people with transfemoral amputation were least likely. Geographic variation in prosthetic prescription exists in the VA and further research is needed to explain why. PMID:26562228

  19. Potential reduction of carbon emissions from Crude Palm Oil production based on energy and carbon balances

    International Nuclear Information System (INIS)

    Highlights: ► We evaluate energy and carbon equivalence from CPO production based on a CBM. ► Energy spent and produced via carbon movement from palm oil mill was determined. ► Scenarios were formulated to evaluate the potential reduction of carbon emission. ► Utilization of biomass from palm oil mill shows the high potential of C-reduction. -- Abstract: This study aimed to evaluate energy and carbon equivalences (CE) associated with palm oil milling and to evaluate sustainability alternatives for energy consumption. Appropriate ways to reduce carbon emissions were also evaluated. A field survey was carried out to quantify the input and output of energy and materials following the conceptual framework of a carbon-balanced model (CBM), which exclude other non-CO2 greenhouse gases. Survey results indicate that the electrical energy consumption for daily mill start-up averaged 18.7 ± 5.4 kWh/ton Fresh Fruit Bunches (FFBs). This energy is equivalent to 114.4 ± 33.2 kWh/ton Crude Palm Oil (CPO) which was found to be offset by that generated in the mills using palm fiber as a solid fuel. Currently, organic residues contained in the wastewater are anaerobically converted to methane. The methane is used as fuel to generate electricity and sold to an outside grid network at a generation rate of 8.1 ± 2.1 kWh/ton FFB. Based on the CBM approach, carbon emissions observed from the use of fossil energy in palm oil milling were very small; however, total carbon emission from oil palm plantation and palm oil milling were found to be 12.3 kg CE/ton FFB, resulting in the net carbon reduction in CPO production of 2.8 kg CE/ton FFB or 53.7 kg CE/ha-y. Overall, the sum of C-reduction was found 1.2 times greater than that of C-emission. This figure can be increased up to 5.5, if all biomass by-products are used as fuel to generate electricity only. The full potential for carbon reduction from palm oil milling is estimated at 0.94 kW of electric power for every hectare of

  20. Carbon Dot Based Sensing of Dopamine and Ascorbic Acid

    Directory of Open Access Journals (Sweden)

    Upama Baruah

    2014-01-01

    Full Text Available We demonstrate carbon dot based sensor of catecholamine, namely, dopamine and ascorbic acid. Carbon dots (CDs were prepared from a green source: commercially available Assam tea. The carbon dots prepared from tea had particle sizes of ∼0.8 nm and are fluorescent. Fluorescence of the carbon dots was found to be quenched in the presence of dopamine and ascorbic acid with greater sensitivity for dopamine. The minimum detectable limits were determined to be 33 μM and 98 μM for dopamine and ascorbic acid, respectively. The quenching constants determined from Stern-Volmer plot were determined to be 5 × 10−4 and 1 × 10−4 for dopamine and ascorbic acid, respectively. A probable mechanism of quenching has been discussed in the paper.

  1. Upper limb prosthetic use in Slovenia.

    Science.gov (United States)

    Burger, H; Marincek, C

    1994-04-01

    The article deals with the use of different types of upper limb prostheses in Slovenia. Four hundred and fourteen upper limb amputees were sent a questionnaire on the type of their prosthesis, its use and reasons for non-use, respectively. The replies were subject to statistical analysis. Most of the questioned upper limb amputees (70%) wear a prosthesis only for cosmesis. The use of a prosthesis depends on the level of upper limb amputation, loss of the dominant hand, and time from amputation. Prosthetic success appears to be unrelated to age at the time of amputation and the rehabilitation programme. The most frequent reason for not wearing a prosthesis is heat and consequent sweating of the stump. More than a third of amputees are dissatisfied with their prostheses.

  2. Gait analysis in lower-limb amputation and prosthetic rehabilitation.

    Science.gov (United States)

    Esquenazi, Alberto

    2014-02-01

    Gait analysis combined with sound clinical judgment plays an important role in elucidating the factors involved in the pathologic prosthetic gait and the selection and effects of available interventions to optimize it. Detailed clinical evaluation of walking contributes to the analysis of the prosthetic gait, but evaluation in the gait laboratory using kinetic and kinematic data is often necessary to quantify and identify the particular contributions of the variables impacting the gait with confidence and assess the results of such intervention. The same approach can be considered when selecting prosthetic components and assessing leg length in this patient population.

  3. Cropland carbon fluxes in the United States: increasing Geospatial Resolution of Inventory-Based Carbon Accounting

    Energy Technology Data Exchange (ETDEWEB)

    West, Tristram O. [ORNL; Brandt, Craig C [ORNL; Baskaran, Latha Malar [ORNL; Hellwinckel, Chad M [ORNL; Marland, Gregg [ORNL; Nelson, Richard G [ORNL; De La Torre Ugarte, Daniel G [ORNL; Post, Wilfred M [ORNL

    2010-01-01

    Net annual soil carbon change, fossil fuel emissions from cropland production, and cropland net primary productivity were estimated and spatially distributed using land cover defined by the Moderate Resolution Imaging Spectroradiometer (MODIS) and by the Cropland Data Layer (CDL). Spatially resolved estimates of net ecosystem exchange (NEE) and net ecosystem carbon balance (NECB) were developed. NEE represents net on-site vertical fluxes of carbon. NECB represents all on-site and off-site carbon fluxes associated with crop production. Estimates of cropland NEE using moderate resolution (~1km2) land cover data were generated for the conterminous US and compared with higher resolution (30m) estimates of NEE and with direct measurements of CO2 flux from croplands in Illinois and Nebraska. Estimates of NEE using the CDL (30m resolution) had a higher correlation with eddy covariance flux tower estimates compared with estimates of NEE using MODIS. Estimates of NECB are primarily driven by net soil carbon change, fossil-fuel emissions associated with crop production, and CO2 emissions from the application of agricultural lime. NEE and NECB for US croplands were -274 and 7 Tg C yr-1 for 2004, respectively. Use of moderate to high resolution satellite-based land cover data enables improved estimates of cropland carbon dynamics.

  4. CARBON-CONTAINING COMPOSITES BASED ON METALS

    Directory of Open Access Journals (Sweden)

    VAGANOV V. E.

    2015-10-01

    Full Text Available Problem statement Among the developed technologies metal-composites production,a special place takes powder metallurgy, having fundamental differences from conventionally used foundry technologies. The main advantages of this technology are: the possibility of sensitive control, the structure and phase composition of the starting components, and ultimately the possibility of obtaining of bulk material in nanostructured state with a minimum of processing steps. The potential reinforcers metals include micro and nano-sized oxides, carbides, nitrides, whiskers. The special position is occupied with carbon nanostructures (CNS: С60 fullerenes, single-layer and multi-layer nanotubes, onions (spherical "bulbs", nano-diamonds and graphite,their properties are being intensively studied in recent years. These objects have a high thermal and electrical conductivity values, superelasticity, and have a strength approximate to the theoretical value, which can provide an obtaining composite nanomaterial with a unique set of physical and mechanical properties. In creation of a metal matrix composite nanomaterials (CM, reinforced by various CNS, a special attention should be given to mechanical activation processes (MA already at the stage of preparation of the starting components affecting the structure, phase composition and properties of aluminum-matrix composites. Purpose. To investigate the influence of mechanical activation on the structure and phase composition of aluminum-matrix composites. Conclusion. The results of the study of the structure and phase composition of the initial and mechanically activated powders and bulk-modified metal-composites are shown, depending on the type and concentration of modifying varieties CNS, regimes of MA and parameters of compaction. The study is conducted of tribological properties of Al-CNS OF nanostructured materials.

  5. Cropland carbon fluxes in the United States: increasing geospatial resolution of inventory-based carbon accounting.

    Science.gov (United States)

    West, Tristram O; Brandt, Craig C; Baskaran, Latha M; Hellwinckel, Chad M; Mueller, Richard; Bernacchi, Carl J; Bandaru, Varaprasad; Yang, Bai; Wilson, Bradly S; Marland, Gregg; Nelson, Richard G; De la Torre Ugarte, Daniel G; Post, Wilfred M

    2010-06-01

    Net annual soil carbon change, fossil fuel emissions from cropland production, and cropland net primary production were estimated and spatially distributed using land cover defined by NASA's moderate resolution imaging spectroradiometer (MODIS) and by the USDA National Agricultural Statistics Service (NASS) cropland data layer (CDL). Spatially resolved estimates of net ecosystem exchange (NEE) and net ecosystem carbon balance (NECB) were developed. The purpose of generating spatial estimates of carbon fluxes, and the primary objective of this research, was to develop a method of carbon accounting that is consistent from field to national scales. NEE represents net on-site vertical fluxes of carbon. NECB represents all on-site and off-site carbon fluxes associated with crop production. Estimates of cropland NEE using moderate resolution (approximately 1 km2) land cover data were generated for the conterminous United States and compared with higher resolution (30-m) estimates of NEE and with direct measurements of CO2 flux from croplands in Illinois and Nebraska, USA. Estimates of NEE using the CDL (30-m resolution) had a higher correlation with eddy covariance flux tower estimates compared with estimates of NEE using MODIS. Estimates of NECB are primarily driven by net soil carbon change, fossil fuel emissions associated with crop production, and CO2 emissions from the application of agricultural lime. NEE and NECB for U.S. croplands were -274 and 7 Tg C/yr for 2004, respectively. Use of moderate- to high-resolution satellite-based land cover data enables improved estimates of cropland carbon dynamics. PMID:20597291

  6. A three-dimensional finite element model of the transibial residual limb and prosthetic socket to predict skin temperatures.

    Science.gov (United States)

    Peery, Jeffrey T; Klute, Glenn K; Blevins, Joanna J; Ledoux, William R

    2006-09-01

    Amputees who wear prosthetic limbs often experience discomfort from blisters and sores due to mechanical insult; these skin conditions are exacerbated by elevated skin temperatures and excessive perspiration within the prosthetic socket. The goal of this study was to create a tool for developing new prostheses that accommodate varying thermal loads arising from everyday activities. A three-dimensional thermal model of a transtibial residual limb and prosthesis was constructed using the finite element (FE) method. Transverse computerized tomography (CT) scans were used to specify the geometry of the residual limb and socket. Thermal properties from the literature were assigned to both biological tissue and prosthetic socket elements. The purpose of this work was to create a model that would aid in testing the effect of new prosthesis designs on skin temperature. To validate its output, the model was used to predict the skin temperature distribution in a common prosthetic socket system (silicone liner, wool sock, and carbon fiber socket) at rest with no mechanical loading. Skin temperatures were generally elevated near muscle and decreased anteriorly and at the distal end. Experimental temperature measurements taken at the skin-prosthesis interface of five human subjects were used to validate the model. Data extracted from the thermal model at anterior, posterior, lateral, and medial locations were typically within one standard deviation of experimental results; the mean temperatures were within 0.3 degree C for each section and were within 0.1 degree C overall.

  7. Vertically Aligned Carbon Nanofiber based Biosensor Platform for Glucose Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Al Mamun, Khandaker A.; Tulip, Fahmida S.; MacArthur, Kimberly; McFarlane, Nicole; Islam, Syed K.; Hensley, Dale

    2014-03-01

    Vertically aligned carbon nanofibers (VACNFs) have recently become an important tool for biosensor design. Carbon nanofibers (CNF) have excellent conductive and structural properties with many irregularities and defect sites in addition to exposed carboxyl groups throughout their surfaces. These properties allow a better immobilization matrix compared to carbon nanotubes and offer better resolution when compared with the FET-based biosensors. VACNFs can be deterministically grown on silicon substrates allowing optimization of the structures for various biosensor applications. Two VACNF electrode architectures have been employed in this study and a comparison of their performances has been made in terms of sensitivity, sensing limitations, dynamic range, and response time. The usage of VACNF platform as a glucose sensor has been verified in this study by selecting an optimum architecture based on the VACNF forest density. Read More: http://www.worldscientific.com/doi/abs/10.1142/S0129156414500062

  8. Carbon anodes for a lithium secondary battery based on polyacrylonitrile

    Energy Technology Data Exchange (ETDEWEB)

    Wu Yuping [Tsinghua Univ., Beijing (China). Inst. of Nuclear Energy Technology]|[Chinese Academy of Sciences, Beijing (China). Inst. of Chemistry; Fang Shibi; Jiang Yingyan [Chinese Academy of Sciences, Beijing (China). Inst. of Chemistry

    1998-10-01

    Carbon anode materials for a lithium secondary battery based on polyacrylonitrile (PAN) are studied by using elemental analysis, X-ray powder diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The reversible lithium capacity and charging voltage curves of carbons from PAN are affected by the heat-treatment temperature, the rate of temperature rise and the soak time. These factors lead to a change in nitrogen content, cyclization and cross-linking processes, the carbon structure, and the number of micropores. The reversible capacity reches 426 mAh g{sup -1} at 600 C; the lower the rate of temperature rise, the higher the reversible capacity. The addition of phosphoric acid can favour the cyclization process of PAN, and can increase the number of micropores in the resulting carbon. It can also act as setting agent for graphene molecules and can improve the regularity of the carbon structure. In addition, the doped phosphorus is bonded with C and O, and dispersed homogeneously in the bulk carbon structure. This results in an increase in d{sub 002}. Such doping can enhance the reversible capacity above and below 0.9 V. (orig.)

  9. Two-degree-of-freedom powered prosthetic wrist

    Directory of Open Access Journals (Sweden)

    Peter J. Kyberd, PhD

    2011-07-01

    Full Text Available Prosthetic wrists need to be compact. By minimizing space requirements, a wrist unit can be made for people with long residual limbs. This prosthetic wrist uses two motors arranged across the arm within the envelope of the hand. The drive is transmitted by a differential so that it produces wrist flexion and extension, pronation and supination, or a combination of both. As a case study, it was controlled by a single-prosthesis user with pattern recognition of the myoelectric signals from the forearm. The result is a compact, two-degree-of-freedom prosthetic wrist that has the potential to improve the functionality of any prosthetic hand by creating a hand orientation that more closely matches grasp requirements.

  10. Hydrogen Adsorption in Carbon-Based Materials Studied by NMR

    Science.gov (United States)

    Wu, Yue; Kleinhammes, Alfred; Anderson, Robert; Mao, Shenghua

    2007-03-01

    Hydrogen adsorption in carbon-based materials such as boron-doped graphite and boron-doped single-walled carbon nanotubes (SWNTs) were investigated by nuclear magnetic resonance (NMR). ^1H NMR is shown to be a sensitive and quantitative probe for detecting adsorbed gas molecules such as H2, methane, and ethane. NMR measurements were carried out in-situ under given H2 pressure up to a pressure of over 100 atm. From such ^1H NMR measurement, the amount of adsorbed H2 molecules was determined versus pressure. This gives an alternative method for measuring the adsorption isotherms where the H2 signature is identified based on spin properties rather than weight or volume as in gravimetric and volumetric measurements. The measurement shows that boron doping has a favorable effect on increasing the adsorption enthalpy of H2 in carbon-based systems. This work was done in collaboration with NREL and Department of Chemistry, University of Pennsylvania, within the DOE Center of Excellence on Carbon-based Hydrogen Storage Materials and is supported by DOE.

  11. Reducing carbon transaction costs in community based forest management

    NARCIS (Netherlands)

    Skutsch, Margaret M.

    2004-01-01

    The paper considers the potential for community based forest management (of existing forests) in developing countries, as a future CDM strategy, to sequester carbon and claim credits in future commitment periods. This kind of forestry is cost effective, and should bring many more benefits to local p

  12. Reducing carbon transaction costs in community-based forest management

    NARCIS (Netherlands)

    Skutsch, Margaret M.

    2005-01-01

    The article considers the potential for community-based forest management (of existing forests) in developing countries, as a future CDM strategy, to sequester and mitigate carbon and to claim credits in future commitment periods. This kind of forestry is cost-effective, and should bring many more b

  13. Prosthetic Knee Septic Arthritis due to Pseudomonas stutzeri

    Directory of Open Access Journals (Sweden)

    Jihad Bishara

    2000-01-01

    Full Text Available Prosthetic joint infection is usually caused by Staphylococcus aureus, coagulase-negative staphylococci and, less commonly, by Gram-negative bacilli and anaerobes. A case of prosthetic joint infection due to Pseudomonas stutzeri in a 73-year-old female with acute promyelocytic leukemia is presented, and the pertinent literature is reviewed. Although the patient had prolonged neutropenia, the infection was successfully treated with antibiotics and without artificial joint replacement.

  14. Carbon dynamics of Oregon and Northern California forests and potential land-based carbon storage.

    Science.gov (United States)

    Hudiburg, Tara; Law, Beverly; Turner, David P; Campbell, John; Donato, Dan; Duane, Maureen

    2009-01-01

    Net uptake of carbon from the atmosphere (net ecosystem production, NEP) is dependent on climate, disturbance history, management practices, forest age, and forest type. To improve understanding of the influence of these factors on forest carbon stocks and flux in the western United States, federal inventory data and supplemental field measurements at additional plots were used to estimate several important components of the carbon balance in forests in Oregon and Northern California during the 1990s. Species- and ecoregion-specific allometric equations were used to estimate live and dead biomass stores, net primary productivity (NPP), and mortality. In the semiarid East Cascades and mesic Coast Range, mean total biomass was 8 and 24 kg C/m2, and mean NPP was 0.30 and 0.78 kg C.m(-2).yr(-1), respectively. Maximum NPP and dead biomass stores were most influenced by climate, whereas maximum live biomass stores and mortality were most influenced by forest type. Within ecoregions, mean live and dead biomass were usually higher on public lands, primarily because of the younger age class distribution on private lands. Decrease in NPP with age was not general across ecoregions, with no marked decline in old stands (>200 years old) in some ecoregions. In the absence of stand-replacing disturbance, total landscape carbon stocks could theoretically increase from 3.2 +/- 0.34 Pg C to 5.9 +/- 1.34 Pg C (a 46% increase) if forests were managed for maximum carbon storage. Although the theoretical limit is probably unattainable, given the timber-based economy and fire regimes in some ecoregions, there is still potential to significantly increase the land-based carbon storage by increasing rotation age and reducing harvest rates. PMID:19323181

  15. Dynamic Investigation of Interface Stress on Below-Knee Residual Limb in a Prosthetic Socket

    Institute of Scientific and Technical Information of China (English)

    贾晓红; 张明; 王人成; 金德闻

    2004-01-01

    The dynamic effects of inertial loads on the interface stresses between a residual limb and the trans-tibial prosthetic socket were investigated. A 3-D nonlinear finite element model, based on the actual geometry of the residual limb, including internal bones and socket liner, was developed to study the mechanical interaction between the socket and the residual limb during walking. To simulate the friction/slip boundary conditions between the skin and liner, automated surface-to-surface contact was used. The results show that interface pressure and shear stress have a similar double-peaked waveform shape in the stance phase. The average difference in interface stresses between the cases with and without consideration of inertial forces is 8.4% in the stance phase and 20.1% in the swing phase. The results suggest that the dynamic effects of inertial loads on interface stress distribution during walking must be considered in prosthetic socket design.

  16. Membrane-based systems for carbon capture and hydrogen purification

    Energy Technology Data Exchange (ETDEWEB)

    Berchtold, Kathryn A [Los Alamos National Laboratory

    2010-11-24

    This presentation describes the activities being conducted at Los Alamos National Laboratory to develop carbon capture technologies for power systems. This work is aimed at continued development and demonstration of a membrane based pre- and post-combustion carbon capture technology and separation schemes. Our primary work entails the development and demonstration of an innovative membrane technology for pre-combustion capture of carbon dioxide that operates over a broad range of conditions relevant to the power industry while meeting the US DOE's Carbon Sequestration Program goals of 90% CO{sub 2} capture at less than a 10% increase in the cost of energy services. Separating and capturing carbon dioxide from mixed gas streams is a first and critical step in carbon sequestration. To be technically and economically viable, a successful separation method must be applicable to industrially relevant gas streams at realistic temperatures and pressures as well as be compatible with large gas volumes. Our project team is developing polymer membranes based on polybenzimidazole (PBI) chemistries that can purify hydrogen and capture CO{sub 2} at industrially relevant temperatures. Our primary objectives are to develop and demonstrate polymer-based membrane chemistries, structures, deployment platforms, and sealing technologies that achieve the critical combination of high selectivity, high permeability, chemical stability, and mechanical stability all at elevated temperatures (> 150 C) and packaged in a scalable, economically viable, high area density system amenable to incorporation into an advanced Integrated Gasification Combined-Cycle (IGCC) plant for pre-combustion CO{sub 2} capture. Stability requirements are focused on tolerance to the primary synthesis gas components and impurities at various locations in the IGCC process. Since the process stream compositions and conditions (temperature and pressure) vary throughout the IGCC process, the project is focused on

  17. Nanoporous Carbide-Derived Carbon Material-Based Linear Actuators

    Directory of Open Access Journals (Sweden)

    Janno Torop

    2009-12-01

    Full Text Available Devices using electroactive polymer-supported carbon material can be exploited as alternatives to conventional electromechanical actuators in applications where electromechanical actuators have some serious deficiencies. One of the numerous examples is precise microactuators. In this paper, we show for first time the dilatometric effect in nanocomposite material actuators containing carbide-derived carbon (CDC and polytetrafluoroetylene polymer (PTFE. Transducers based on high surface area carbide-derived carbon electrode materials are suitable for short range displacement applications, because of the proportional actuation response to the charge inserted, and high Coulombic efficiency due to the EDL capacitance. The material is capable of developing stresses in the range of tens of N cm-2. The area of an actuator can be dozens of cm2, which means that forces above 100 N are achievable. The actuation mechanism is based on the interactions between the high-surface carbon and the ions of the electrolyte. Electrochemical evaluations of the four different actuators with linear (longitudinal action response are described. The actuator electrodes were made from two types of nanoporous TiC-derived carbons with surface area (SA of 1150 m2 g-1 and 1470 m2 g-1, respectively. Two kinds of electrolytes were used in actuators: 1.0 M tetraethylammonium tetrafluoroborate (TEABF4 solution in propylene carbonate and pure ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMITf. It was found that CDC based actuators exhibit a linear movement of about 1% in the voltage range of 0.8 V to 3.0 V at DC. The actuators with EMITf electrolyte had about 70% larger movement compared to the specimen with TEABF4 electrolyte.

  18. Rotationplasty with Vascular Reconstruction for Prosthetic Knee Joint Infection

    Directory of Open Access Journals (Sweden)

    Masahide Fujiki

    2015-01-01

    Full Text Available Rotationplasty is used most often as a function-preserving salvage procedure after resection of sarcomas of the lower extremity; however, it is also used after infection of prosthetic knee joints. Conventional vascular management during rotationplasty is to preserve and coil major vessels, but recently, transection and reanastomosis of the major vessels has been widely performed. However, there has been little discussion regarding the optimal vascular management of rotationplasty after infection of prosthetic knee joints because rotationplasty is rarely performed for this indication. We reviewed four patients who had undergone resection of osteosarcomas of the femur, placement of a prosthetic knee joint, and rotationplasty with vascular reconstruction from 2010 to 2013. The mean interval between prosthetic joint replacement and rotationplasty was 10.4 years and the mean interval between the diagnosis of prosthesis infection and rotationplasty was 7.9 years. Rotationplasty was successful in all patients; however, in one patient, arterial thrombosis developed and necessitated urgent surgical removal and arterial reconstruction. All patients were able to walk independently with a prosthetic limb after rehabilitation. Although there is no consensus regarding the most appropriate method of vascular management during rotationplasty for revision of infected prosthetic joints, vascular transection and reanastomosis is a useful option.

  19. Predicting prosthetic prescription after major lower-limb amputation.

    Science.gov (United States)

    Resnik, Linda; Borgia, Matthew

    2015-01-01

    We describe prosthetic limb prescription in the first year following lower-limb amputation and examine the relationship between amputation level, geographic region, and prosthetic prescription. We analyzed 2005 to 2010 Department of Veterans Affairs (VA) Inpatient and Medical Encounters SAS data sets, Vital Status death data, and National Prosthetic Patient Database data for 9,994 Veterans who underwent lower-limb amputation at a VA hospital. Descriptive statistics and bivariates were examined. Cox proportional hazard models identified factors associated with prosthetic prescription. Analyses showed that amputation level was associated with prosthetic prescription. The hazard ratios (HRs) were 1.41 for ankle amputation and 0.46 for transfemoral amputation compared with transtibial amputation. HRs for geographic region were Northeast = 1.49, Upper Midwest = 1.26, and West = 1.39 compared with the South (p amputation were most likely to be prescribed a prosthesis and people with transfemoral amputation were least likely. Geographic variation in prosthetic prescription exists in the VA and further research is needed to explain why.

  20. Production of graphene oxide from pitch-based carbon fiber

    OpenAIRE

    Miyeon Lee; Jihoon Lee; Sung Young Park; Byunggak Min; Bongsoo Kim; Insik In

    2015-01-01

    Pitch-based graphene oxide (p-GO) whose compositional/structural features are comparable to those of graphene oxide (GO) was firstly produced by chemical exfoliation of pitch-based carbon fiber rather than natural graphite. Incorporation of p-GO as nanofillers into poly(methyl methacrylate) (PMMA) as a matrix polymer resulted in excellent mechanical reinforcement. p-GO/PMMA nanocomposite (1 wt.-% p-GO) demonstrated 800% higher modulus of toughness of neat PMMA.

  1. Engineered Carbon-Nanomaterial-Based Electrochemical Sensors for Biomolecules.

    Science.gov (United States)

    Tiwari, Jitendra N; Vij, Varun; Kemp, K Christian; Kim, Kwang S

    2016-01-26

    The study of electrochemical behavior of bioactive molecules has become one of the most rapidly developing scientific fields. Biotechnology and biomedical engineering fields have a vested interest in constructing more precise and accurate voltammetric/amperometric biosensors. One rapidly growing area of biosensor design involves incorporation of carbon-based nanomaterials in working electrodes, such as one-dimensional carbon nanotubes, two-dimensional graphene, and graphene oxide. In this review article, we give a brief overview describing the voltammetric techniques and how these techniques are applied in biosensing, as well as the details surrounding important biosensing concepts of sensitivity and limits of detection. Building on these important concepts, we show how the sensitivity and limit of detection can be tuned by including carbon-based nanomaterials in the fabrication of biosensors. The sensing of biomolecules including glucose, dopamine, proteins, enzymes, uric acid, DNA, RNA, and H2O2 traditionally employs enzymes in detection; however, these enzymes denature easily, and as such, enzymeless methods are highly desired. Here we draw an important distinction between enzymeless and enzyme-containing carbon-nanomaterial-based biosensors. The review ends with an outlook of future concepts that can be employed in biosensor fabrication, as well as limitations of already proposed materials and how such sensing can be enhanced. As such, this review can act as a roadmap to guide researchers toward concepts that can be employed in the design of next generation biosensors, while also highlighting the current advancements in the field.

  2. Engineered Carbon-Nanomaterial-Based Electrochemical Sensors for Biomolecules.

    Science.gov (United States)

    Tiwari, Jitendra N; Vij, Varun; Kemp, K Christian; Kim, Kwang S

    2016-01-26

    The study of electrochemical behavior of bioactive molecules has become one of the most rapidly developing scientific fields. Biotechnology and biomedical engineering fields have a vested interest in constructing more precise and accurate voltammetric/amperometric biosensors. One rapidly growing area of biosensor design involves incorporation of carbon-based nanomaterials in working electrodes, such as one-dimensional carbon nanotubes, two-dimensional graphene, and graphene oxide. In this review article, we give a brief overview describing the voltammetric techniques and how these techniques are applied in biosensing, as well as the details surrounding important biosensing concepts of sensitivity and limits of detection. Building on these important concepts, we show how the sensitivity and limit of detection can be tuned by including carbon-based nanomaterials in the fabrication of biosensors. The sensing of biomolecules including glucose, dopamine, proteins, enzymes, uric acid, DNA, RNA, and H2O2 traditionally employs enzymes in detection; however, these enzymes denature easily, and as such, enzymeless methods are highly desired. Here we draw an important distinction between enzymeless and enzyme-containing carbon-nanomaterial-based biosensors. The review ends with an outlook of future concepts that can be employed in biosensor fabrication, as well as limitations of already proposed materials and how such sensing can be enhanced. As such, this review can act as a roadmap to guide researchers toward concepts that can be employed in the design of next generation biosensors, while also highlighting the current advancements in the field. PMID:26579616

  3. Resorcinol–formaldehyde based carbon nanospheres by electrospraying

    Indian Academy of Sciences (India)

    Chandra S Sharma; Sandip Patil; Suman Saurabh; Ashutosh Sharma; R Venkataraghavan

    2009-06-01

    Carbon nanospheres were synthesized using sol–gel processing of organic and aqueous resorcinol formaldehyde (RF) sols combined with electrospraying technique. RF sol was electrosprayed to form nanodroplets which were collected on a Si wafer. After oven drying at 60°C for 12 h, RF nano-droplets were pyrolyzed at 900°C in an inert atmosphere to yield the carbon nanospheres. This study reports the optimization of various process parameters including needle diameter, applied electric potential and liquid flow rate in order to get spherical, mono-disperse particles. For the organic RF sol, the optimized parameters, needle diameter 0.241 mm, electric potential, 1.5 kV/cm and a flow rate of 0.8 ml/h, enabled the synthesis of nearly monodispersed carbon nano-spheres with diameter of 30.2 ± 7.1 nm. With the same conditions, aqueous RF sol produced irregularly shaped nanoparticles with a smaller mean diameter and much higher variance (17.4 ± 8.0 nm). The surface properties were significantly influenced by the surface morphologies as demonstrated by the water contact angle (WCA) studies. The surface covered with the RF derived carbon nano-spheres was extremely hydrophilic (WCA 10.1°) as compared to a much weaker hydrophilicity of the RF derived carbon films (WCA 83.3°). The hydrophilic carbon nanospheres reported here may have potential applications as adsorbents and in controlled drug delivery, biosensors and carbon-based microelectromechanical systems (C-MEMS) including bio-MEMS.

  4. The "true" incidence of surgically treated deep prosthetic joint infection after 32,896 primary total hip arthroplasties

    DEFF Research Database (Denmark)

    Gundtoft, Per Hviid; Overgaard, Søren; Schønheyder, Henrik Carl;

    2015-01-01

    BACKGROUND AND PURPOSE: It has been suggested that the risk of prosthetic joint infection (PJI) in patients with total hip arthroplasty (THA) may be underestimated if based only on arthroplasty registry data. We therefore wanted to estimate the "true" incidence of PJI in THA using several data...

  5. Working cycles of devices based on bistable carbon nanotubes

    Science.gov (United States)

    Shklyaev, Oleg; Mockensturm, Eric; Crespi, Vincent; Carbon Nanotubes Collaboration

    2013-03-01

    Shape-changing nanotubes are an example of variable-shape sp2 carbon-based systems where the competition between strain and surface energies can be moderated by an externally controllable stimuli such as applied voltage, temperature, or pressure of gas encapsulated inside the tube. Using any of these stimuli one can transition a bistable carbon nanotube between the collapsed and inflated states and thus perform mechanical work. During the working cycle of such a device, energy from an electric or heat source is transferred to mechanical energy. Combinations of these stimuli allow the system to convert energy between different sources using the bistable shape-changing tube as a mediator. For example, coupling a bistable carbon nanotube to the heat and charge reservoirs can enable energy transfer between heat and electric forms. The developed theory can be extended to other nano-systems which change configurations in response to external stimuli.

  6. Dental Prosthetic Status and Prosthetic Needs of Institutionalised Elderly Population in Oldage Homes of Jabalpur City, Madhya Pradesh, India

    OpenAIRE

    Deogade, Suryakant C.; Vinay, S.; Naidu, Sonal

    2012-01-01

    Oral disorders are cumulative throughout life and hence unfavourable outcomes are likely to be greatest among the elderly. A descriptive cross-sectional study was conducted among institutionalized geriatric population in old-age homes of Jabalpur city, Madhya Pradesh, to assess their prosthetic status and prosthetic needs. A cross-sectional survey was conducted in all the four old-age homes of Jabalpur city, Madhya Pradesh state, India. All residents aged 60 years and above formed the study p...

  7. Hybrid Aluminum Composite Materials Based on Carbon Nanostructures

    Directory of Open Access Journals (Sweden)

    Tatiana S. Koltsova

    2015-09-01

    Full Text Available We investigated formation of carbon nanofibers grown by chemical deposition (CVD method using an acetylene-hydrogen mixture on the surface of micron-sized aluminum powder particles. To obtain uniform distribution of the carbon nanostructures on the particles we deposited nickel catalyst on the surface by spraying from the aqueous solution of nickel nitrate. It was found that increasing the time of the synthesis lowers the rate of growth of carbon nanostructures due to the deactivation of the catalyst. The Raman spectroscopy measurements confirm the presence of disordered carbon corresponding to CNFs in the specimen. X-ray photoelectron spectroscopy showed the presence of aluminum carbide in the hot pressed samples. An aluminum composite material prepared using 1 wt.% CNFs obtained by uniaxial cold pressing and sintering showed 30% increase in the hardness compared to pure aluminum, whereas the composites prepared by hot pressing showed 80% increase in the hardness. Composite materials have satisfactory ductility. Thus, the aluminum based material reinforced with carbon nanostructures should be appropriate for creating high-strength and light compacts for aerospace and automotive applications and power engineering.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7355

  8. Carbon microelectromechanical systems (C-MEMS) based microsupercapacitors

    KAUST Repository

    Agrawal, Richa

    2015-05-18

    The rapid development in miniaturized electronic devices has led to an ever increasing demand for high-performance rechargeable micropower scources. Microsupercapacitors in particular have gained much attention in recent years owing to their ability to provide high pulse power while maintaining long cycle lives. Carbon microelectromechanical systems (C-MEMS) is a powerful approach to fabricate high aspect ratio carbon microelectrode arrays, which has been proved to hold great promise as a platform for energy storage. C-MEMS is a versatile technique to create carbon structures by pyrolyzing a patterned photoresist. Furthermore, different active materials can be loaded onto these microelectrode platforms for further enhancement of the electrochemical performance of the C-MEMS platform. In this article, different techniques and methods in order to enhance C-MEMS based various electrochemical capacitor systems have been discussed, including electrochemical activation of C-MEMS structures for miniaturized supercapacitor applications, integration of carbon nanostructures like carbon nanotubes onto C-MEMS structures and also integration of pseudocapacitive materials such as polypyrrole onto C-MEMS structures. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  9. Design characteristics of pediatric prosthetic knees.

    Science.gov (United States)

    Andrysek, Jan; Naumann, Stephen; Cleghorn, William L

    2004-12-01

    We examined whether pediatric prosthetic single-axis knees can theoretically provide the beneficial functional characteristics of polycentric knees and the design considerations needed to realize this. Five children and their parents provided subjective opinions of the relative importance of functional requirements (FRs) for the knee. FRs related to comfort, fatigue, stability, and falling were found to be of high importance, while sitting appearance and adequate knee flexion were of lower importance. Relationships were drawn between these FRs and deductions were made regarding the importance of associated design parameters. Stance-phase control was rated to be of greatest importance followed by toe clearance. Models were developed for five knees including four- and six-bar knees, corresponding to two commercially available components, and for three configurations of a single-axis knee. Stance-phase control, specifically stability after heel-strike and swing-phase initiation at push-off, and toe clearance were simulated. The results suggest that a single-axis knee design incorporating stance-phase control will mutually satisfy the identified set of highly and moderately important FRs. PMID:15614992

  10. Prosthetic rehabilitation of the upper limb amputee

    Directory of Open Access Journals (Sweden)

    Bernard O′Keeffe

    2011-01-01

    Full Text Available The loss of all or part of the arm is a catastrophic event for a patient and a significant challenge to rehabilitation professionals and prosthetic engineers. The large, upper extremity amputee population in India has, historically, been poorly served, with most having no access to support or being provided with ineffective prostheses. In recent years, the arrival of organisations like Otto Bock has made high quality service standards and devices accessible to more amputees. This review attempts to provide surgeons and other medical professionals with an overview of the multidisciplinary, multistage rehabilitation process and the solution options available. With worldwide upper extremity prosthesis rejection rates at significant levels, the review also describes some of the factors which influence the outcome. This is particularly relevant in the Indian context where the service can involve high cost investments. It is the responsibility of all contributing professionals to guide vulnerable patients through the process and try to maximise the benefit that can be obtained within the resources available.

  11. Toxicology of antimicrobial nanoparticles for prosthetic devices

    Science.gov (United States)

    Nuñez-Anita, Rosa Elvira; Acosta-Torres, Laura Susana; Vilar-Pineda, Jorge; Martínez-Espinosa, Juan Carlos; de la Fuente-Hernández, Javier; Castaño, Víctor Manuel

    2014-01-01

    Advances in nanotechnology are producing an accelerated proliferation of new nanomaterial composites that are likely to become an important source of engineered health-related products. Nanoparticles with antifungal effects are of great interest in the formulation of microbicidal materials. Fungi are found as innocuous commensals and colonize various habitats in and on humans, especially the skin and mucosa. As growth on surfaces is a natural part of the Candida spp. lifestyle, one can expect that Candida organisms colonize prosthetic devices, such as dentures. Macromolecular systems, due to their properties, allow efficient use of these materials in various fields, including the creation of reinforced nanoparticle polymers with antimicrobial activity. This review briefly summarizes the results of studies conducted during the past decade and especially in the last few years focused on the toxicity of different antimicrobial polymers and factors influencing their activities, as well as the main applications of antimicrobial polymers in dentistry. The present study addresses aspects that are often overlooked in nanotoxicology studies, such as careful time-dependent characterization of agglomeration and ion release. PMID:25187703

  12. Peri-prosthetic fracture vibration testing

    Energy Technology Data Exchange (ETDEWEB)

    Cruce, Jesse R [Los Alamos National Laboratory; Erwin, Jenny R [Los Alamos National Laboratory; Remick, Kevin R [Los Alamos National Laboratory; Cornwell, Phillip J [Los Alamos National Laboratory; Menegini, R. Michael [INDIANA UNIV.; Racanelli, Joe [STRYKER ORTHOPARDICS

    2010-11-08

    The purpose of this study was to establish a test setup and vibration analysis method to predict femoral stem seating and prevent bone fracture using accelerometer and force response data from an instrumented stem and impactor. This study builds upon earlier studies to identify a means to supplement a surgeon's tactile and auditory senses by using damage identification techniques normally used for civil and mechanical structures. Testing was conducted using foam cortical shell sawbones prepared for stems of different geometries. Each stem was instrumented with an accelerometer. Two impactor designs were compared: a monolithic impactor and a two-piece impactor, each with an integrated load cell and accelerometer. Acceleration and force measurements were taken in the direction of impaction. Comparisons between different methods of applying an impacting force were made, including a drop tower and a surgical hammer. The effect of varying compliance on the data was also investigated. The ultimate goal of this study was to assist in the design of an integrated portable data acquisition system capable of being used in future cadaveric testing. This paper will discuss the experimental setup and the subsequent results of the comparisons made between impactors, prosthetic geometries, compliances, and impact methods. The results of this study can be used for both future replicate testing as well as in a cadaveric environment.

  13. Paper-based ultracapacitors with carbon nanotubes-graphene composites

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jian, E-mail: lijian@gwu.edu, E-mail: keidar@gwu.edu; Cheng, Xiaoqian; Brand, Cameron; Shashurin, Alexey; Keidar, Michael, E-mail: lijian@gwu.edu, E-mail: keidar@gwu.edu [Department of Mechanical and Aerospace Engineering, The George Washington University, Washington, DC 20052 (United States); Sun, Jianwei; Reeves, Mark [Department of Physics, The George Washington University, Washington, DC 20052 (United States)

    2014-04-28

    In this paper, a paper-based ultracapacitors were fabricated by the rod-rolling method with the ink of carbon nanomaterials, which were synthesized by arc discharge under various magnetic conditions. Composites of carbon nanostructures, including high-purity single-walled carbon nanotubes (SWCNTs) and graphene flakes were synthesized simultaneously in a magnetically enhanced arc. These two nanostructures have promising electrical properties and synergistic effects in the application of ultracapacitors. Scanning electron microscope, transmission electron microscope, and Raman spectroscopy were employed to characterize the properties of carbon nanostructures and their thin films. The sheet resistance of the SWCNT and composite thin films was also evaluated by four-point probe from room temperature to the cryogenic temperature as low as 90 K. In addition, measurements of cyclic voltammetery and galvanostatic charging/discharging showed the ultracapacitor based on composites possessed a superior specific capacitance of up to 100 F/g, which is around three times higher than the ultracapacitor entirely fabricated with SWCNT.

  14. Constraining future terrestrial carbon cycle projections using observation-based water and carbon flux estimates.

    Science.gov (United States)

    Mystakidis, Stefanos; Davin, Edouard L; Gruber, Nicolas; Seneviratne, Sonia I

    2016-06-01

    The terrestrial biosphere is currently acting as a sink for about a third of the total anthropogenic CO2  emissions. However, the future fate of this sink in the coming decades is very uncertain, as current earth system models (ESMs) simulate diverging responses of the terrestrial carbon cycle to upcoming climate change. Here, we use observation-based constraints of water and carbon fluxes to reduce uncertainties in the projected terrestrial carbon cycle response derived from simulations of ESMs conducted as part of the 5th phase of the Coupled Model Intercomparison Project (CMIP5). We find in the ESMs a clear linear relationship between present-day evapotranspiration (ET) and gross primary productivity (GPP), as well as between these present-day fluxes and projected changes in GPP, thus providing an emergent constraint on projected GPP. Constraining the ESMs based on their ability to simulate present-day ET and GPP leads to a substantial decrease in the projected GPP and to a ca. 50% reduction in the associated model spread in GPP by the end of the century. Given the strong correlation between projected changes in GPP and in NBP in the ESMs, applying the constraints on net biome productivity (NBP) reduces the model spread in the projected land sink by more than 30% by 2100. Moreover, the projected decline in the land sink is at least doubled in the constrained ensembles and the probability that the terrestrial biosphere is turned into a net carbon source by the end of the century is strongly increased. This indicates that the decline in the future land carbon uptake might be stronger than previously thought, which would have important implications for the rate of increase in the atmospheric CO2 concentration and for future climate change. PMID:26732346

  15. Automated hexahedral mesh generation from biomedical image data: applications in limb prosthetics.

    Science.gov (United States)

    Zachariah, S G; Sanders, J E; Turkiyyah, G M

    1996-06-01

    A general method to generate hexahedral meshes for finite element analysis of residual limbs and similar biomedical geometries is presented. The method utilizes skeleton-based subdivision of cross-sectional domains to produce simple subdomains in which structured meshes are easily generated. Application to a below-knee residual limb and external prosthetic socket is described. The residual limb was modeled as consisting of bones, soft tissue, and skin. The prosthetic socket model comprised a socket wall with an inner liner. The geometries of these structures were defined using axial cross-sectional contour data from X-ray computed tomography, optical scanning, and mechanical surface digitization. A tubular surface representation, using B-splines to define the directrix and generator, is shown to be convenient for definition of the structure geometries. Conversion of cross-sectional data to the compact tubular surface representation is direct, and the analytical representation simplifies geometric querying and numerical optimization within the mesh generation algorithms. The element meshes remain geometrically accurate since boundary nodes are constrained to lie on the tubular surfaces. Several element meshes of increasing mesh density were generated for two residual limbs and prosthetic sockets. Convergence testing demonstrated that approximately 19 elements are required along a circumference of the residual limb surface for a simple linear elastic model. A model with the fibula absent compared with the same geometry with the fibula present showed differences suggesting higher distal stresses in the absence of the fibula. Automated hexahedral mesh generation algorithms for sliced data represent an advancement in prosthetic stress analysis since they allow rapid modeling of any given residual limb and optimization of mesh parameters.

  16. State-of-the-art materials used for maxillofacial prosthetic reconstruction.

    Science.gov (United States)

    Lontz, J F

    1990-04-01

    The present state-of-the-art rests primarily on three general types of polymeric materials based on chemical configurations, that of polyacrylates, polydimethylsiloxane, and segmented block polyetherurethanes. Each of these types is currently prominent in a wide range of dental prosthodontics and surgical prosthetics with continued chemical variants emerging to attain enhanced biocompatibility for safety and effectiveness. However, owing to the disproportionally lower demand, the state-of-the-art for maxillofacial restorative prosthetics has not focused adequately on the specific array of the properties needed for the ideal prosthesis. To approach the ideality will require synthesizing new molecular configurations adjusted with component structures either as block copolymers or as intermediate oligomers. The synthetic effects must have a comprehensive plan of immediate assessments on terms of biocompatibility for safety to orofacial tissues and effective durability against all conceivable deterioration of the chemical structure. Above all, inasmuch as the skilled art and techniques of maxillofacial prosthetics is a custom-made specialty allied to the prosthodontics, the improved material for ideality should be readily amenable to molding by the well-established dental stone mold technology, for reasons of cost and simplicity. PMID:2186936

  17. Secure Microprocessor-Controlled Prosthetic Leg for Elderly Amputees: Preliminary Results

    Directory of Open Access Journals (Sweden)

    S. Krut

    2011-01-01

    Full Text Available We introduce a new prosthetic leg design, adapted to elderly trans-femoral amputees. Technical progress in prosthesis design mainly concerns active individuals. An important number of elderly amputees are not very mobile, tire easily, present reduced muscle strength, and have difficulties managing their balance. Therefore, the needs and characteristics of this specific population are very different from those of younger ones and the prosthetic solutions are not adapted. Our artificial knee has been designed to fulfill the specific requirements of this population in terms of capabilities, transfer assistance, security, intuitiveness, simplicity of use, and types of physical activity to be performed. We particularly focused our efforts on ensuring safe and secure stand-to-sit transfers. We developed an approach to control the different states of the prosthetic joint (blocked, free, resistant, associated with different physical activities. Amputee posture and motion are observed through a single multi-axis force sensor embedded in the prosthesis. The patient behaves naturally, while the controller analyses his movements in order to detect his intention to sit down. The detection algorithm is based on a reference pattern, calibrated individually, to which the sensor data are compared, and submitted to a set of tests allowing the discrimination of the intention to sit down from other activities. Preliminary validation of the system has been performed in order to verify the applicability of the prosthesis to different tasks: walking, standing, sitting down, standing up, picking up an object from a chair, slope and stair climbing.

  18. Prosthetic Rehabilitation of Patients After Surgical Treatment of Maxillary Tumors with Respect to Upper Airway Protection.

    Science.gov (United States)

    Rolski, D; Kostrzewa-Janicka, J; Nieborak, R; Przybyłowska, D; Stopa, Z; Mierzwińska-Nastalska, E

    2016-01-01

    As a consequence of surgical treatment of maxillary tumors, a connection between oral and nasal cavities is formed, which leads to serious functional disorders, manifested by inability to normally ingest food, proper speech articulation, and to respiratory route disorders and upper airway inflammation. These morphological and functional disorders are intensified by adjunctive radio- or chemotherapy. The aim of this paper is to present different possible methods of rehabilitation, including application of interim obturators and individually planned prosthetic restorations to improve respiratory efficiency in patients after extensive maxillary resections. In the course of prosthetic treatment, cooperation with the laryngologist to consider every aspect of chronic paranasal sinusitis, accompanied by concurrent inflammation of oral, nasal, or laryngeal mucous membranes, was of paramount importance. Based on the quality of life questionnaire, used in this study, evident improvement in the masticatory efficiency, speech articulation, and respiration was observed. Particularly good effects were obtained in edentulous patients, in whom implant-prosthetic treatment was possible to apply. Comprehensive and multidisciplinary care of postoperative patients greatly contributes to their better quality of life and facilitates their return to prior living conditions, as well as to occupational and family lives. PMID:26820729

  19. A powered prosthetic intervention for bilateral transfemoral amputees.

    Science.gov (United States)

    Lawson, Brian E; Ruhe, Brian; Shultz, Amanda; Goldfarb, Michael

    2015-04-01

    This paper presents the design and validation of a control system for a pair of powered knee and ankle prostheses to be used as a prosthetic intervention for bilateral transfemoral amputees. The control system leverages communication between the prostheses for enhanced awareness and stability, along with power generation at the knee and ankle joints to better restore biomechanical functionality in level ground walking. The control methodology employed is a combination of an impedance-based framework for weight-bearing portions of gait and a trajectory-based approach for the nonweight-bearing portions. The control system was implemented on a pair of self-contained powered knee and ankle prostheses, and the ability of the prostheses and control approach to provide walking functionality was assessed in a set of experimental trials with a bilateral transfemoral amputee subject. Specifically, experimental data from these trials indicate that the powered prostheses and bilateral control architecture provide gait kinematics that reproduce healthy gait kinematics to a greater extent than the subject's daily-use passive prostheses.

  20. Carbon Nanotubes Based Glucose Needle-type Biosensor

    Directory of Open Access Journals (Sweden)

    Hong Li

    2008-03-01

    Full Text Available A novel needle-type biosensor based on carbon nanotubes is reported. Thebiosensor was prepared by packing a mixture of multi-wall carbon nanotubes (MWCNTs,graphite powder and glucose oxidase (Gox freeze-dried powder into a glass capillary of 0.5mm inner diameter. The resulting amperometric biosensor was characterizedelectrochemically using amperometry in the presence of hydrogen peroxide and in thepresence of glucose. The glucose biosensor sensitivity was influenced by the glucoseoxidase concentration within the MWCNTs mixture. The optimized glucose needle-typebiosensor displayed better sensitivity and stability, and a detected range of up to 20 mM.Based on its favorable stability, the needle biosensor was first time used in real-timemonitoring system as a kind of online glucose detector. The decay of current response isless than 10% after 24-hour continuous observation.

  1. Carbon based materials for electronic bio-sensing

    Directory of Open Access Journals (Sweden)

    Maria D. Angione

    2011-09-01

    Full Text Available Bio-sensing represents one of the most attractive applications of carbon material based electronic devices; nevertheless, the complete integration of bioactive transducing elements still represents a major challenge, particularly in terms of preserving biological function and specificity while maintaining the sensor's electronic performance. This review highlights recent advances in the realization of field-effect transistor (FET based sensors that comprise a bio-receptor within the FET channel. A birds-eye view will be provided of the most promising classes of active layers as well as different device architectures and methods of fabrication. Finally, strategies for interfacing bio-components with organic or carbon nano-structured electronic active layers are reported.

  2. Smart Behavior of Carbon Fiber Reinforced Cement-based Composite

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The electrical characteristics of cement-based material can be remarkably improved by the addition of short carbon fibers.Carbon fiber reinforced cement composite (CFRC) is an intrinsically smart material that can sense not only the stress andstrain, but also the temperature. In this paper, variations of electrical resistivity with external applied load, and relationof thermoelectric force and temperature were investigated. Test results indicated that the electrical signal is related to theincrease in the material volume resistivity during crack generation or propagation and the decrease in the resistivity duringcrack closure. Moreover, it was found that the fiber addition increased the linearity and reversibility of the Seebeck effect inthe cement-based materials. The change of electrical characteristics reflects large amount of information of inner damage andtemperature differential of composite, which can be used for stress-strain or thermal self-monitoring by embedding it in theconcrete structures.

  3. Electric Double-layer Capacitor Based on Activated Carbon Material

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this study electric double-layer capacitors (EDLCs) based on activated carbon material and organic electrolyte (tetraethyl ammonium tetrafluoroborate) were explored. The fabrication method for EDLC is presented and the performance of EDLC was examined by using the cyclic voltammetry, constant-current charging and discharging technique, electrochemical impedance spectroscopy measurements. Influence of various components and design parameters on the performance of the capacitors were preliminarily investigated. Up to now, EDLC based on carbon materials can deliver 20.7 W/kg at the discharge rate ofI=0.3 mA, together with the energy density of 8.5 Wh/kg. Equivalent series resistance (ESR) is 0.716 Ω.cm2. The specific power of the capacitor is low and further attempts to raise the power capability of the capacitors are necessary. Some considerations are put forward to further improve the performance of EDLC.

  4. Carbon Nanotube Based Spike Neuromorphic Devices and Circuits

    OpenAIRE

    Shen, Alex

    2014-01-01

    Fabrication and operation of carbon nanotube (CNT) based electronic devices called "synapstors," with the goal of emulating the functions of biological synapses, are reported. These synapstors have a structure akin to field-effect transistors, utilizing a random network of single-wall semiconducting CNTs as its conducting channel. Analog spike signal processing with low power consumption was demonstrated. These synaptic devices are capable of carrying out logic, learning, and memory functions...

  5. Wideband electrical characterisation of carbon-based nanocomposites

    OpenAIRE

    Molenberg, Isabel

    2012-01-01

    Nanocomposite materials are composed of two or more different materials having different physical properties forming distinct ‘phases’. At least one of these constituents has dimensions of the order of the nanometre and the properties of these nanoparticles lead to the creation of a unique composite material. In particular, nanocomposites based on high aspect ratio particles like carbon nanotubes should exhibit outstanding mechanical, thermal and electrical properties at very small particle c...

  6. Strain Sensors Based on Carbon Nanotube - Polymer Coatings

    OpenAIRE

    Grabowski, Krzysztof; Zbyrad, Paulina; Wilmański, Alan; Uhl, Tadeusz

    2014-01-01

    In this work there have been investigated the potential usage of the CNT's as strain sensors for the structural health monitoring based on the spray coatings. Experimental work was performed on the metal and glass-reinforced composites. Multiwalled Carbon Nanotubes (MWCNTs) were mixed with different matrix materials (acrylic and epoxy) and then applied to the test material with the use of two techniques (screen printing and spray coating). Futhermore, sensors were investigated using SEM. Resp...

  7. DNA Based Carbon Nanotube Porphyrin Nanohybrids Molecular Recognization and Regeneration

    OpenAIRE

    Riccitelli, Molly M; Zhang, Hanyu; Choi, Jong Hyun

    2013-01-01

    In the search to improve solar cells, scientists are exploring new materials that will provide better current transfer. One material that has emerged as a strong contender is the single walled carbon nanotube (SWNT). Current DNA-SWNT based films combined with chromophores have poor operational lifetimes compared to commercial solar cells. Once exposed to light the chromophore begins to degrade, eventually rendering the solar cell unusable. To solve this problem, we used a method involving mul...

  8. Microstructure and properties of pitch-based carbon composites

    Science.gov (United States)

    Blanco; Santamaria; Bermejo; Bonhomme; Menendez

    1999-11-01

    Pitches prepared in the laboratory by thermal treatment and air-blowing of a commercial coal-tar pitch were used as matrix precursors of carbon composites using granular petroleum coke, foundry coke, amorphous graphite and anthracite. Pitches were characterized by standard procedures (elemental analysis, softening point, solubility tests and carbon yield) and light microscopy (mesophase content). Pitch pyrolysis behaviour was monitored by thermogravimetric analysis and from the optical texture of cokes. Pitch wettability to the different carbons, at different temperatures, was also studied. Experimental conditions selected for the preparation of composites were based on pitch composition and properties. The main microstructural features of composites were determined by light microscopy and scanning electron microscopy. Composite properties were described in terms of their density, porosity and compressive strength, and related to composite microstructure and the characteristics of the precursors. Thermal treatment and air-blowing of pitch improved carbon composite structure and properties. The lowest porosities and best mechanical properties were observed in those composites obtained with the thermally treated pitches combined with foundry coke and anthracite.

  9. Carbon-based strong solid acid for cornstarch hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Nata, Iryanti Fatyasari, E-mail: yanti_tkunlam@yahoo.com [Chemical Engineering Study Program, Faculty of Engineering, Lambung Mangkurat University, Jl. A. Yani Km. 36 Banjarbaru, South Kalimantan 70714 (Indonesia); Irawan, Chairul; Mardina, Primata [Chemical Engineering Study Program, Faculty of Engineering, Lambung Mangkurat University, Jl. A. Yani Km. 36 Banjarbaru, South Kalimantan 70714 (Indonesia); Lee, Cheng-Kang, E-mail: cklee@mail.ntust.edu.tw [Department of Chemical Engineering, National Taiwan University of Science and Technology, 43 Keelung Rd. Sec.4, Taipei 106, Taiwan (China)

    2015-10-15

    Highly sulfonated carbonaceous spheres with diameter of 100–500 nm can be generated by hydrothermal carbonization of glucose in the presence of hydroxyethylsulfonic acid and acrylic acid at 180 °C for 4 h. The acidity of the prepared carbonaceous sphere C4-SO{sub 3}H can reach 2.10 mmol/g. It was used as a solid acid catalyst for the hydrolysis of cornstarch. Total reducing sugar (TRS) concentration of 19.91 mg/mL could be obtained by hydrolyzing 20 mg/mL cornstarch at 150 °C for 6 h using C4-SO{sub 3}H as solid acid catalyst. The solid acid catalyst demonstrated good stability that only 9% decrease in TRS concentration was observed after five repeat uses. The as-prepared carbon-based solid acid catalyst can be an environmentally benign replacement for homogeneous catalyst. - Highlights: • Carbon solid acid was successfully prepared by one-step hydrothermal carbonization. • The acrylic acid as monomer was effectively reduce the diameter size of particle. • The solid acid catalyst show good catalytic performance of starch hydrolysis. • The solid acid catalyst is not significantly deteriorated after repeated use.

  10. Feasibility of Haze Governance Based on Carbon Sink Mode

    Institute of Scientific and Technical Information of China (English)

    Jie; HE; Quanquan; WANG

    2015-01-01

    In recent years,there are research findings of haze formation in various fields of academic circle. It has proved that causes of haze take on diverse characteristics. Thus,from both the natural and human perspective,haze governance should be diverse. Research conclusions on causes of haze formation mainly focus on special geographical structure,and meteorological factors such as relatively stable atmosphere,high rate of calm wind,high relative humidity and temperature of air,and human factors such as industrial pollution,automotive exhaust emissions,aerosol pollution,eutrophication of soil water,and change of city underlying surface. Carbon sink mode is a new channel for haze governance.In carbon sink mode,it is feasible to regulate relative humidity and temperature in air,enhance global wind,and reduce fine particles and microorganisms of air pollution,so as to reduce haze pollution. Besides,China’s special potential of carbon sink market makes it possible to govern haze on the base of carbon sink.

  11. Lignin-based carbon fibers: Carbon nanotube decoration and superior thermal stability

    KAUST Repository

    Xu, Xuezhu

    2014-08-23

    Lignin-based carbon fibers (CFs) decorated with carbon nanotubes (CNTs) were synthesized and their structure, thermal stability and wettability were systematically studied. The carbon fiber precursors were produced by electrospinning lignin/polyacrylonitrile solutions. CFs were obtained by pyrolyzing the precursors and CNTs were subsequently grown on the CFs to eventually achieve a CF–CNT hybrid structure. The processes of pyrolysis and CNT growth were conducted in a tube furnace using different conditions and the properties of the resultant products were studied and compared. The CF–CNT hybrid structure produced at 850 °C using a palladium catalyst showed the highest thermal stability, i.e., 98.3% residual weight at 950 °C. A mechanism for such superior thermal stability was postulated based on the results from X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopy, and electron energy loss spectroscopy analyses. The dense CNT decoration was found to increase the hydrophobicity of the CFs.

  12. Consumer satisfaction in prosthetics and orthotics facilities.

    Science.gov (United States)

    Geertzen, J H B; Gankema, H G J; Groothoff, J W; Dijkstra, P U

    2002-04-01

    The aim of this study was to assess consumer/patient satisfaction with the services of the prosthetics and orthotics (P&O) facilities in the north of the Netherlands, using a modified SERVQUAL questionnaire. In this questionnaire, consumer interests and experiences are assessed on a 5-point Likert scale. The questionnaire consisted of 30 items covering 5 domains: tangibles, reliability, responsiveness, assurance and empathy and the consumers were invited to give an overall rating of satisfaction (scale 1-10). Consumers of four P&O facilities were asked to participate. In total 496 consumers (aged 0-76) participated; 279 consumers received orthopaedic shoes and 217 consumers received either prostheses or orthoses. An overall satisfaction rating of 8 or higher was given by 75% of the consumers (mean 8.0; sd=1.2). Consumers were defined as satisfied with the services of the P&O facility if they rated their experiences on a certain item equal or better than their rating of its importance. Eighty-five percent (85%) or more of the consumers were satisfied with the P&O facility in 24 of the 30 (80%) items of the SERVQUAL questionnaire. Of the 6 less unsatisfying items, 3 were related to the domain "tangibles", 2 were related to the domain "empathy" and 1 to the domain "responsiveness". The management of the P&O facility can use this information to increase consumer satisfaction by improving quality and service at these items. In general, the degree of consumer overall satisfaction was not related to age, gender, and type of assistive device or "length of relationship of consumer" and P&O facility. Only consumers who received orthopaedic shoes rated their overall satisfaction significantly lower (0.3) than consumers who received other types of devices. This difference is clinically not relevant. PMID:12043928

  13. Consumer satisfaction in prosthetics and orthotics facilities.

    Science.gov (United States)

    Geertzen, J H B; Gankema, H G J; Groothoff, J W; Dijkstra, P U

    2002-04-01

    The aim of this study was to assess consumer/patient satisfaction with the services of the prosthetics and orthotics (P&O) facilities in the north of the Netherlands, using a modified SERVQUAL questionnaire. In this questionnaire, consumer interests and experiences are assessed on a 5-point Likert scale. The questionnaire consisted of 30 items covering 5 domains: tangibles, reliability, responsiveness, assurance and empathy and the consumers were invited to give an overall rating of satisfaction (scale 1-10). Consumers of four P&O facilities were asked to participate. In total 496 consumers (aged 0-76) participated; 279 consumers received orthopaedic shoes and 217 consumers received either prostheses or orthoses. An overall satisfaction rating of 8 or higher was given by 75% of the consumers (mean 8.0; sd=1.2). Consumers were defined as satisfied with the services of the P&O facility if they rated their experiences on a certain item equal or better than their rating of its importance. Eighty-five percent (85%) or more of the consumers were satisfied with the P&O facility in 24 of the 30 (80%) items of the SERVQUAL questionnaire. Of the 6 less unsatisfying items, 3 were related to the domain "tangibles", 2 were related to the domain "empathy" and 1 to the domain "responsiveness". The management of the P&O facility can use this information to increase consumer satisfaction by improving quality and service at these items. In general, the degree of consumer overall satisfaction was not related to age, gender, and type of assistive device or "length of relationship of consumer" and P&O facility. Only consumers who received orthopaedic shoes rated their overall satisfaction significantly lower (0.3) than consumers who received other types of devices. This difference is clinically not relevant.

  14. Methods for characterization of mechanical and electrical prosthetic vacuum pumps

    Directory of Open Access Journals (Sweden)

    Oluseeni Komolafe, PhD

    2013-11-01

    Full Text Available Despite increasingly widespread adoption of vacuum-assisted suspension systems in prosthetic clinical practices, there remain gaps in the body of scientific knowledge guiding clinicians’ choices of existing products. In this study, we identified important pump-performance metrics and developed techniques to objectively characterize the evacuation performance of prosthetic vacuum pumps. The sensitivity of the proposed techniques was assessed by characterizing the evacuation performance of two electrical (Harmony e-Pulse [Ottobock; Duderstadt, Germany] and LimbLogic VS [Ohio Willow Wood; Mt. Sterling, Ohio] and three mechanical (Harmony P2, Harmony HD, and Harmony P3 [Ottobock] prosthetic pumps in bench-top testing. Five fixed volume chambers ranging from 33 cm3 (2 in.3 to 197 cm3 (12 in.3 were used to represent different air volume spaces between a prosthetic socket and a liner-clad residual limb. All measurements were obtained at a vacuum gauge pressure of 57.6 kPa (17 inHg. The proposed techniques demonstrated sensitivity to the different electrical and mechanical pumps and, to a lesser degree, to the different setting adjustments of each pump. The sensitivity was less pronounced for the mechanical pumps, and future improvements for testing of mechanical vacuum pumps were proposed. Overall, this study successfully offers techniques feasible as standards for assessing the evacuation performance of prosthetic vacuum pump devices.

  15. Methods for characterization of mechanical and electrical prosthetic vacuum pumps.

    Science.gov (United States)

    Komolafe, Oluseeni; Wood, Sean; Caldwell, Ryan; Hansen, Andrew; Fatone, Stefania

    2013-01-01

    Despite increasingly widespread adoption of vacuum-assisted suspension systems in prosthetic clinical practices, there remain gaps in the body of scientific knowledge guiding clinicians' choices of existing products. In this study, we identified important pump-performance metrics and developed techniques to objectively characterize the evacuation performance of prosthetic vacuum pumps. The sensitivity of the proposed techniques was assessed by characterizing the evacuation performance of two electrical (Harmony e-Pulse [Ottobock; Duderstadt, Germany] and LimbLogic VS [Ohio Willow Wood; Mt. Sterling, Ohio]) and three mechanical (Harmony P2, Harmony HD, and Harmony P3 [Ottobock]) prosthetic pumps in bench-top testing. Five fixed volume chambers ranging from 33 cm(3) (2 in.(3)) to 197 cm(3) (12 in.(3)) were used to represent different air volume spaces between a prosthetic socket and a liner-clad residual limb. All measurements were obtained at a vacuum gauge pressure of 57.6 kPa (17 inHg). The proposed techniques demonstrated sensitivity to the different electrical and mechanical pumps and, to a lesser degree, to the different setting adjustments of each pump. The sensitivity was less pronounced for the mechanical pumps, and future improvements for testing of mechanical vacuum pumps were proposed. Overall, this study successfully offers techniques feasible as standards for assessing the evacuation performance of prosthetic vacuum pump devices.

  16. Biomechanical design considerations for transradial prosthetic interface: A review.

    Science.gov (United States)

    Sang, Yuanjun; Li, Xiang; Luo, Yun

    2016-03-01

    Traditional function and comfort assessment of transradial prostheses pay scant attention to prosthetic interface. With better understanding of the biomechanics of prosthetic interface comes better efficiency and safety for interface design; in this way, amputees are more likely to accept prosthetic usage. This review attempts to provide design and selection criteria of transradial interface for prosthetists and clinicians. Various transradial socket types in the literature were chronologically reviewed. Biomechanical discussion of transradial prosthetic interface design from an engineering point of view was also done. Suspension control, range of motion, stability, as well as comfort and safety of socket designs have been considered in varying degrees in the literature. The human-machine interface design should change from traditional "socket design" to new "interface design." From anatomy and physiology to biomechanics of the transradial residual limb, the force and motion transfer, together with comfort and safety, are the two main aspects in prosthetic interface design. Load distribution and transmission should mainly rely on achieving additional skeletal control through targeted soft tissue relief. Biomechanics of the residual limb soft tissues should be studied to find the relationship between mechanical properties and the comfort and safety of soft tissues.

  17. Prosthetic alignment effects on gait symmetry: a case study.

    Science.gov (United States)

    Andres, R O; Stimmel, S K

    1990-05-01

    The loss of a significant portion of a lower extremity causes changes in the usual pattern of human ambulation. These changes have been documented kinematically, kinetically and metabolically, giving insight into the costs of limb amputation relative to ambulatory efforts. The role of the prosthetist is to provide a limb substitute to achieve the best gait performance, while assuring maximum comfort for the patient. This case study examined the effects of antero-posterior alignment of a below-knee prosthesis on sagittal plane gait kinematics by comparing the anatomical side with the prosthetic side. The greatest changes due to variations of alignment were found during the prosthetic stance phase; knee angles showed the greatest asymmetry between anatomical and prosthetic sides. The stance phase on the prosthetic side was reduced with anterior socket displacement due to early knee flexion and toe-off. Posterior socket displacement caused a greater maximum centre of gravity height, but anterior socket displacement caused greater knee flexion which decreased the maximum centre of gravity height. Asymmetries in temporal and other kinematic parameters were not always minimal at the optimal alignment subjectively selected by a certified prosthetist. Comparisons of asymmetry ratios with prosthetic side data revealed the subclinical sensitivity of this amputee to antero-posterior alignment discrepancies.

  18. Amperometric biosensor based on glassy carbon electrode modified with long-length carbon nanotube and enzyme

    Science.gov (United States)

    Furutaka, Hajime; Nemoto, Kentaro; Inoue, Yuki; Hidaka, Hiroki; Muguruma, Hitoshi; Inoue, Hitoshi; Ohsawa, Tatsuya

    2016-05-01

    An amperometric biosensor based on a glassy carbon electrode modified with long-length multiwalled carbon nanotubes (MWCNTs) and enzyme nicotinamide-adenine-dinucleotide-dependent glucose dehydrogenase (GDH) is presented. We demonstrate the effect of the MWCNT length on the amperometric response of the enzyme biosensor. The long length of MWCNT is 200 µm (average), whereas the normal length of MWCNT is 1 µm (average). The response of the long MWCNT–GDH electrode is 2 times more sensitive than that of the normal-length MWCNT–GDH electrode in the concentration range from 0.25–35 mM. The result of electrochemical impedance spectroscopy measurements suggest that the long-length MWCNT–GDH electrode formed a better electron transfer network than the normal-length one.

  19. Carbon nanobuds based on carbon nanotube caps: a first-principles study

    Science.gov (United States)

    Choi, Ji Il; Kim, Hyo Seok; Kim, Han Seul; Lee, Ga In; Kang, Jeung Ku; Kim, Yong-Hoon

    2016-01-01

    Based on density functional theory calculations, we here show that the formation of a fullerene C60 carbon ``nanobud'' (CNB) on carbon nanotube (CNT) caps is energetically more favorable than that on CNT sidewalls. The dominant CNB formation mode for CNT caps is found to be the [2 + 2] cycloaddition reaction as in the conventional CNT sidewall case. However, it is identified to be exothermic in contrast to the endothermic reaction on CNT sidewalls. Computed reaction pathways further demonstrate that the formation (dissociation) barrier for the CNT cap-based CNB is slightly lower (significantly higher) than that of the CNT sidewall-based CNB, indicating an easier CNB formation as well as a higher structural stability. Additionally, performing matrix Green's function calculations, we study the charge transport properties of the CNB/metal electrode interfaces, and show that the C60 bonding to the CNT cap or open end induces resonant transmissions near the Fermi level. It is also found that the good electronic linkage in the CNT cap-C60 cycloaddition bonds results in the absence of quantum interference patterns, which contrasts with the case of the CNB formed on an open-ended CNT that shows a Fano resonance profile.Based on density functional theory calculations, we here show that the formation of a fullerene C60 carbon ``nanobud'' (CNB) on carbon nanotube (CNT) caps is energetically more favorable than that on CNT sidewalls. The dominant CNB formation mode for CNT caps is found to be the [2 + 2] cycloaddition reaction as in the conventional CNT sidewall case. However, it is identified to be exothermic in contrast to the endothermic reaction on CNT sidewalls. Computed reaction pathways further demonstrate that the formation (dissociation) barrier for the CNT cap-based CNB is slightly lower (significantly higher) than that of the CNT sidewall-based CNB, indicating an easier CNB formation as well as a higher structural stability. Additionally, performing matrix Green

  20. Risk-Based Comparison of Carbon Capture Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Engel, David W.; Dalton, Angela C.; Dale, Crystal; Jones, Edward

    2013-05-01

    In this paper, we describe an integrated probabilistic risk assessment methodological framework and a decision-support tool suite for implementing systematic comparisons of competing carbon capture technologies. Culminating from a collaborative effort among national laboratories under the Carbon Capture Simulation Initiative (CCSI), the risk assessment framework and the decision-support tool suite encapsulate three interconnected probabilistic modeling and simulation components. The technology readiness level (TRL) assessment component identifies specific scientific and engineering targets required by each readiness level and applies probabilistic estimation techniques to calculate the likelihood of graded as well as nonlinear advancement in technology maturity. The technical risk assessment component focuses on identifying and quantifying risk contributors, especially stochastic distributions for significant risk contributors, performing scenario-based risk analysis, and integrating with carbon capture process model simulations and optimization. The financial risk component estimates the long-term return on investment based on energy retail pricing, production cost, operating and power replacement cost, plan construction and retrofit expenses, and potential tax relief, expressed probabilistically as the net present value distributions over various forecast horizons.

  1. Carbon-Nanotube-Based Electrodes for Biomedical Applications

    Science.gov (United States)

    Li, Jun; Meyyappan, M.

    2008-01-01

    A nanotube array based on vertically aligned nanotubes or carbon nanofibers has been invented for use in localized electrical stimulation and recording of electrical responses in selected regions of an animal body, especially including the brain. There are numerous established, emerging, and potential applications for localized electrical stimulation and/or recording, including treatment of Parkinson s disease, Tourette s syndrome, and chronic pain, and research on electrochemical effects involved in neurotransmission. Carbon-nanotube-based electrodes offer potential advantages over metal macroelectrodes (having diameters of the order of a millimeter) and microelectrodes (having various diameters ranging down to tens of microns) heretofore used in such applications. These advantages include the following: a) Stimuli and responses could be localized at finer scales of spatial and temporal resolution, which is at subcellular level, with fewer disturbances to, and less interference from, adjacent regions. b) There would be less risk of hemorrhage on implantation because nano-electrode-based probe tips could be configured to be less traumatic. c) Being more biocompatible than are metal electrodes, carbon-nanotube-based electrodes and arrays would be more suitable for long-term or permanent implantation. d) Unlike macro- and microelectrodes, a nano-electrode could penetrate a cell membrane with minimal disruption. Thus, for example, a nanoelectrode could be used to generate an action potential inside a neuron or in proximity of an active neuron zone. Such stimulation may be much more effective than is extra- or intracellular stimulation via a macro- or microelectrode. e) The large surface area of an array at a micron-scale footprint of non-insulated nanoelectrodes coated with a suitable electrochemically active material containing redox ingredients would make it possible to obtain a pseudocapacitance large enough to dissipate a relatively large amount of electric charge

  2. Carbon-based strong solid acid for cornstarch hydrolysis

    Science.gov (United States)

    Nata, Iryanti Fatyasari; Irawan, Chairul; Mardina, Primata; Lee, Cheng-Kang

    2015-10-01

    Highly sulfonated carbonaceous spheres with diameter of 100-500 nm can be generated by hydrothermal carbonization of glucose in the presence of hydroxyethylsulfonic acid and acrylic acid at 180 °C for 4 h. The acidity of the prepared carbonaceous sphere C4-SO3H can reach 2.10 mmol/g. It was used as a solid acid catalyst for the hydrolysis of cornstarch. Total reducing sugar (TRS) concentration of 19.91 mg/mL could be obtained by hydrolyzing 20 mg/mL cornstarch at 150 °C for 6 h using C4-SO3H as solid acid catalyst. The solid acid catalyst demonstrated good stability that only 9% decrease in TRS concentration was observed after five repeat uses. The as-prepared carbon-based solid acid catalyst can be an environmentally benign replacement for homogeneous catalyst.

  3. Lignin Based Carbon Materials for Energy Storage Applications

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Sabornie [ORNL; Saito, Tomonori [ORNL; Rios, Orlando [ORNL; Johs, Alexander [ORNL

    2014-01-01

    The implementation of Li-ion battery technology into electric and hybrid electric vehicles and portable electronic devices such as smart phones, laptops and tablets, creates a demand for efficient, economic and sustainable materials for energy storage. However, the high cost and long processing time associated with manufacturing battery-grade anode and cathode materials are two big constraints for lowering the total cost of batteries and environmentally friendly electric vehicles. Lignin, a byproduct of the pulp and paper industry and biorefinery, is one of the most abundant and inexpensive natural biopolymers. It can be efficiently converted to low cost carbon fibers with optimal properties for use as anode materials. Recent developments in the preparation of lignin precursors and conversion to carbon fiber-based anode materials have created a new class of anode materials with excellent electrochemical characteristics suitable for immediate use in existing Li- or Na-ion battery technologies.

  4. Carbon Nano tubes Based Mixed Matrix Membrane for Gas Separation

    International Nuclear Information System (INIS)

    Carbon nano tubes based mixed matrix membrane (MMM) was prepared by the solution casting method in which the functionalized multi walled carbon nano tubes (f-MWNTs) were embedded into the polyimide membrane and the resulting membranes were characterized. The effect of nominal MWNTs content between 0.5 and 1.0 wt % on the gas separation properties were looked into. The morphologies of the MMM also indicated that at 0.7 % loading of f- MWNTs, the structures of the MMM showed uniform finger-like structures which have facilitated the fast gas transport through the polymer matrix. It may also be concluded that addition of open ended and shortened MWNTs to the polymer matrix can improve its permeability by increasing diffusivity through the MWNTs smooth cavity. (author)

  5. CVD synthesis of carbon-based metallic photonic crystals

    CERN Document Server

    Zakhidov, A A; Baughman, R H; Iqbal, Z

    1999-01-01

    Three-dimensionally periodic nanostructures on the scale of hundreds of nanometers, known as photonic crystals, are attracting increasing interest because of a number of exciting predicted properties. In particular, interesting behavior should be obtainable for carbon- based structures having a dimensional scale larger than fullerenes and nanotubes, but smaller than graphitic microfibers. We show here how templating of porous opals by chemical vapor deposition (CVD) allows us to obtain novel types of graphitic nanostructures. We describe the synthesis of new cubic forms of carbon having extended covalent connectivity in three dimensions, which provide high electrical conductivity and unit cell dimensions comparable to optical wavelengths. Such materials are metallic photonic crystals that show intense Bragg diffraction. (14 refs).

  6. A Taste Sensor Based on a Carbon Nanotube

    Science.gov (United States)

    Takagi, Keisuke; Hirata, Takamichi; Akiya, Masahiro

    A taste sensor consisting of a back-gate type field effect transistor(FET) chip based on carbon nanotube compound materials[poly(ethylene glycol)(PEG)-grafted single-walled carbon nanotubes(PEG-SWNTs)] was developed. The results of impedance measurements for five tastes (sourness, saltiness, bitterness, sweetness, and umami), are shown much difference for specific tastes which are difficult to identify by using Langmuir-Blodgett(LB)film. Moreover, the sensor is able to distinguish most of the experimental taste materials with a short response time. Characteristics of the sensor involve in taste material concentration , initial impedance and frequency characteristics. A clear difference is observed over five basic taste materials.

  7. Surgical-prosthetic treatment of large mandibular cysts

    Directory of Open Access Journals (Sweden)

    Džambas Ljubiša D.

    2003-01-01

    Full Text Available This paper presents a combined surgical-prosthetic procedure of reconstructing mandibular bone defect in a 53 year old patient, following enucleation of a mandibular cyst (Cystectomy Partsch II. After a thorough diagnostic evaluation, a surgical procedure was planned with the particular attention to the nature of the disease, patient’s condition, size and extension of the cyst, tissue loss, and the possibilities of prosthetic management of a mandibular bone defect with partial postresection dental prosthesis. It is of great importance to point to the significance of teamwork of a maxillofacial surgeon and a specialist in prosthodontics. This kind of cooperation provided very effective and less risky soft tissue, as well as bone tissue regeneration (osteogenesis. The patient’s recovery was fast, and he could return to his daily activities and work without significant changes regarding quality of life after surgery and prosthetic treatment.

  8. 基于Fuzzy-CMAC的人体假肢系统智能控制方法研究%Study on Intelligent Control of Human Body Prosthetic Leg Based on Fuzzy-CMAC

    Institute of Scientific and Technical Information of China (English)

    喻洪流; 徐兆红; 卢博睿; 张定国

    2012-01-01

    To meet the need of parameter personalization and walking speed variance of patients, leg prostheses have parameter systems with complex features including nonlinearity and parameter uncertainty, however conventional mathematic models can not meet the demand for the actual control because the IPL knee torque is indirectly caused by the nonlinear damping at the knee joint. Hence intelligent prosthetic leg (IPL) system is required. In this work a dynamic model of self-made hydraulic IPL with the nonlinear damper control parameters and hip torque was established, and an inverse dynamic compound controller of PD-FCMAC for tracking the knee swing was designed. A case simulation showed that an arbitrary trajectory could be tracked in less than 5 s, which proved that the designed controller had high real-time performance with good precision.%由于需要适应患者的参数个性化与步速变化,人体大腿假肢系统参数具有模型非线性与参数不确定性等复杂系统特性,因此需要寻求有效的智能控制方法.以一种自制的液压型智能大腿假肢结构为例,首先建立基于非线性阻尼控制参数与人体髋关节力矩的人机动力学模型,根据智能假腿的复杂系统特性设计一种PD-FCMAC逆动态复合控制模型,实现膝关节轨迹跟踪控制.以所建立的假腿实验样机动力学模型为对象,对PD-FCMAC方法进行实验仿真.实验结果表明,大腿假肢膝关节可以在约0.5s时间内跟踪好目标曲线,具有良好的实时性与精度,且获得的膝关节阻力矩结果与膝关节角度曲线的循环交变规律一致.

  9. Base hydrolysis kinetics of HMX-based explosives using sodium carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, R.L.; Skidmore, C.; Flesner, R.L.; Dell`orco, P.C.; Spontarelli, T.; Uher, K.J.; Kramer, J.F. [Los Alamos National Lab., NM (United States); Bell, D.A. [Wyoming Univ., Laramie, WY (United States)

    1996-07-01

    Sodium carbonate has been identified as a possible hydrolysis reagent for decomposing HMX-based explosives to water soluble, non-energetic products. In this study, the reaction kinetics of sodium carbonate hydrolysis are examined and a reaction model is developed. The rate of hydrolysis is reaction rate limited, opposed to mass transfer limited, up to 150{degrees}C. Greater than 99% of the explosive solids in powder form are destroyed in less than 10 minutes at a temperature of 150{degrees}C. The primary products from sodium carbonate hydrolysis are sodium nitrite, formate, nitrate, acetate, glycolate, hexamine, nitrogen gas, nitrous oxide, and ammonia.

  10. Uncemented allograft-prosthetic composite reconstruction of the proximal femur

    Directory of Open Access Journals (Sweden)

    Li Min

    2014-01-01

    Full Text Available Background: Allograft-prosthetic composite can be divided into three groups names cemented, uncemented, and partially cemented. Previous studies have mainly reported outcomes in cemented and partially cemented allograft-prosthetic composites, but have rarely focused on the uncemented allograft-prosthetic composites. The objectives of our study were to describe a surgical technique for using proximal femoral uncemented allograft-prosthetic composite and to present the radiographic and clinical results. Materials and Methods: Twelve patients who underwent uncemented allograft-prosthetic composite reconstruction of the proximal femur after bone tumor resection were retrospectively evaluated at an average followup of 24.0 months. Clinical records and radiographs were evaluated. Results: In our series, union occurred in all the patients (100%; range 5-9 months. Until the most recent followup, there were no cases with infection, nonunion of the greater trochanter, junctional bone resorption, dislocation, allergic reaction, wear of acetabulum socket, recurrence, and metastasis. But there were three periprosthetic fractures which were fixed using cerclage wire during surgery. Five cases had bone resorption in and around the greater trochanter. The average Musculoskeletal Tumor Society (MSTS score and Harris hip score (HHS were 26.2 points (range 24-29 points and 80.6 points (range 66.2-92.7 points, respectively. Conclusions: These results showed that uncemented allograft-prosthetic composite could promote bone union through compression at the host-allograft junction and is a good choice for proximal femoral resection. Although this technology has its own merits, long term outcomes are yet not validated.

  11. Predicting the effective thermal conductivity of carbon nanotube based nanofluids

    Energy Technology Data Exchange (ETDEWEB)

    Sastry, N N Venkata; Bhunia, Avijit; Sundararajan, T; Das, Sarit K [Department of Mechanical Engineering, Indian Institute of Technology, Madras, Chennai 600 036 (India)

    2008-02-06

    Adding a small volume fraction of carbon nanotubes (CNTs) to a liquid enhances the thermal conductivity significantly. Recent experimental findings report an anomalously wide range of enhancement values that continue to perplex the research community and remain unexplained. In this paper we present a theoretical model based on three-dimensional CNT chain formation (percolation) in the base liquid and the corresponding thermal resistance network. The model considers random CNT orientation and CNT-CNT interaction forming the percolating chain. Predictions are in good agreement with almost all available experimental data. Results show that the enhancement critically depends on the CNT geometry (length), volume fraction, thermal conductivity of the base liquid and the nanofluid (CNT-liquid suspension) preparation technique. Based on the physical mechanism of heat conduction in the nanofluid, we introduce a new dimensionless parameter that alone characterizes the nanofluid thermal conductivity with reasonable accuracy ({approx} {+-} 5%)

  12. Towards a carbon-negative sustainable bio-based economy

    Directory of Open Access Journals (Sweden)

    Bartel eVanholme

    2013-06-01

    Full Text Available The bio-based economy relies on sustainable, plant-derived resources for fuels, chemicals, materials, food and feed rather than on the evanescent usage of fossil resources. The cornerstone of this economy is the biorefinery, in which renewable resources are intelligently converted to a plethora of products, maximizing the valorization of the feedstocks. Innovation is a prerequisite to move a fossil-based economy towards sustainable alternatives, and the viability of the bio-based economy depends on the integration between plant (green and industrial (white biotechnology. Green biotechnology deals with primary production through the improvement of biomass crops, while white biotechnology deals with the conversion of biomass into products and energy. Waste streams are minimized during these processes or partly converted to biogas, which can be used to power the processing pipeline. The sustainability of this economy is guaranteed by a third technology pillar that uses thermochemical conversion to valorize waste streams and fix residual carbon as biochar in the soil, hence creating a carbon-negative cycle. These three different multidisciplinary pillars interact through the value chain of the bio-based economy.

  13. Towards a carbon-negative sustainable bio-based economy.

    Science.gov (United States)

    Vanholme, Bartel; Desmet, Tom; Ronsse, Frederik; Rabaey, Korneel; Van Breusegem, Frank; De Mey, Marjan; Soetaert, Wim; Boerjan, Wout

    2013-01-01

    The bio-based economy relies on sustainable, plant-derived resources for fuels, chemicals, materials, food and feed rather than on the evanescent usage of fossil resources. The cornerstone of this economy is the biorefinery, in which renewable resources are intelligently converted to a plethora of products, maximizing the valorization of the feedstocks. Innovation is a prerequisite to move a fossil-based economy toward sustainable alternatives, and the viability of the bio-based economy depends on the integration between plant (green) and industrial (white) biotechnology. Green biotechnology deals with primary production through the improvement of biomass crops, while white biotechnology deals with the conversion of biomass into products and energy. Waste streams are minimized during these processes or partly converted to biogas, which can be used to power the processing pipeline. The sustainability of this economy is guaranteed by a third technology pillar that uses thermochemical conversion to valorize waste streams and fix residual carbon as biochar in the soil, hence creating a carbon-negative cycle. These three different multidisciplinary pillars interact through the value chain of the bio-based economy. PMID:23761802

  14. Performance of carbon-based hot frit substrates: I, Low pressure helium and hydrogen testing

    International Nuclear Information System (INIS)

    The performance of various carbon-based materials in flowing, high-temperature helium and hydrogen is described. These materials which are candidate hot frit substrates for possible application in a PBR include various grades of graphite, carbon-carbon and vitreous carbon. Vitreous carbon showed extremely good performance in helium, while that of the various graphite grades was quite variable and, in some cases, poor. Purified grades performed better than unpurified grades, but in all cases large sample-to-sample variations in weight loss were observed. For carbon-carbon samples, the performance was intermediate. Since the weight loss in these samples was in large measure due to the loss of the densification media, improvements in the performance of carbon-carbon may be possible. With respect to the performance in hydrogen, high weight losses were observed, re-enforcing the need for coating carbon-based materials for service in a flowing hydrogen environment

  15. Performance of carbon-based hot frit substrates: I, Low pressure helium and hydrogen testing

    Energy Technology Data Exchange (ETDEWEB)

    Barletta, R.; Adams, J.; Svandrlik, J.; Powell, J.R.

    1993-07-01

    The performance of various carbon-based materials in flowing, high-temperature helium and hydrogen is described. These materials which are candidate hot frit substrates for possible application in a PBR include various grades of graphite, carbon-carbon and vitreous carbon. Vitreous carbon showed extremely good performance in helium, while that of the various graphite grades was quite variable and, in some cases, poor. Purified grades performed better than unpurified grades, but in all cases large sample-to-sample variations in weight loss were observed. For carbon-carbon samples, the performance was intermediate. Since the weight loss in these samples was in large measure due to the loss of the densification media, improvements in the performance of carbon-carbon may be possible. With respect to the performance in hydrogen, high weight losses were observed, re-enforcing the need for coating carbon-based materials for service in a flowing hydrogen environment.

  16. Influence of metal-containing carbon fibers on the properties of carbon-filled plastics based on aromatic polyamide

    Science.gov (United States)

    Burya, A. I.; Safonova, A. M.; Rula, I. V.

    2012-07-01

    The influence of metal-containing carbon fibers on the thermal properties of carbon-filled phenylone-based plastics has been investigated. It has been shown that carbometallic fibers containing in their composition 20- 30 mass % of a finely dispersed metal (Co, Cu) are promising fillers of phenylone C-2 for making carbonfilled plastics working in frictional units of various machines and mechanisms.

  17. Copper-based Composite Materials Reinforced with Carbon Nanostructures

    Directory of Open Access Journals (Sweden)

    Tatiana Larionova

    2015-09-01

    Full Text Available The present work is devoted to development of high performance Cu-based material reinforced with carbon. For this purpose Cu-C composite powders were produced by one-step CVD process. The powders containing carbon nanofibers and graphene were subjected to compacting and analyzed. Mechanical properties of Cu-carbon nanofibers (CNFs and Cu-graphene composites were compared to traditional Cu-graphite and pure copper samples compacted under the same technology. Cu-CNFs material showed the best performance (1.7 times increase in the hardness compared to copper, that is primarily explained by the smallest matrix grain size, which growth is inhibited by the homogeneously dispersed CNFs. Friction coefficient of the Cu-(17-33vol.%CNF was found to be 9 times less than that of pure copper and coincides within the error with Cu-graphite, however the wear of Cu-33vol.%CNF reduced by more than 2 times over Cu-33vol.% graphite samples.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7348

  18. Dental prosthetic status and prosthetic needs of institutionalised elderly population in oldage homes of jabalpur city, madhya pradesh, India.

    Science.gov (United States)

    Deogade, Suryakant C; Vinay, S; Naidu, Sonal

    2013-12-01

    Oral disorders are cumulative throughout life and hence unfavourable outcomes are likely to be greatest among the elderly. A descriptive cross-sectional study was conducted among institutionalized geriatric population in old-age homes of Jabalpur city, Madhya Pradesh, to assess their prosthetic status and prosthetic needs. A cross-sectional survey was conducted in all the four old-age homes of Jabalpur city, Madhya Pradesh state, India. All residents aged 60 years and above formed the study population. The recording of prosthetic status and prosthetic needs was carried out according to the World Health Organisation (WHO) Oral Health Assessment Form (1997). A total of 224 individuals were included in the study of which 123 were females and 101 were males. Seventy five percent of the females and 55 % of the males had no prostheses in their upper arch and 61 % of the females and 76 % of the males had no prostheses in their lower arch. More number of males presented with 'Bridges' in their upper arch when compared to females (P value = 0.006). Highest prosthetic need in males was multi-unit prosthesis (42 % in upper arch and 41 % in lower arch) whereas, females' required full prosthesis (39 % in both the upper arch and lower arches). Ageing presents some formidable challenges, particularly with the institutionalised. This study clearly demonstrates a high insufficiency of prosthetic care among the institutionalized elderly population. Any preparation towards the provision of oral health care should not be limited to treatment alone but, more importantly focus on empowering this elderly community with information and education programmes. PMID:24431796

  19. Dental prosthetic status and prosthetic needs of institutionalised elderly population in oldage homes of jabalpur city, madhya pradesh, India.

    Science.gov (United States)

    Deogade, Suryakant C; Vinay, S; Naidu, Sonal

    2013-12-01

    Oral disorders are cumulative throughout life and hence unfavourable outcomes are likely to be greatest among the elderly. A descriptive cross-sectional study was conducted among institutionalized geriatric population in old-age homes of Jabalpur city, Madhya Pradesh, to assess their prosthetic status and prosthetic needs. A cross-sectional survey was conducted in all the four old-age homes of Jabalpur city, Madhya Pradesh state, India. All residents aged 60 years and above formed the study population. The recording of prosthetic status and prosthetic needs was carried out according to the World Health Organisation (WHO) Oral Health Assessment Form (1997). A total of 224 individuals were included in the study of which 123 were females and 101 were males. Seventy five percent of the females and 55 % of the males had no prostheses in their upper arch and 61 % of the females and 76 % of the males had no prostheses in their lower arch. More number of males presented with 'Bridges' in their upper arch when compared to females (P value = 0.006). Highest prosthetic need in males was multi-unit prosthesis (42 % in upper arch and 41 % in lower arch) whereas, females' required full prosthesis (39 % in both the upper arch and lower arches). Ageing presents some formidable challenges, particularly with the institutionalised. This study clearly demonstrates a high insufficiency of prosthetic care among the institutionalized elderly population. Any preparation towards the provision of oral health care should not be limited to treatment alone but, more importantly focus on empowering this elderly community with information and education programmes.

  20. Hybrid Carbon-Based Nanostructured Platforms for the Advanced Bioreactors.

    Science.gov (United States)

    Levchenko, I; Mai-Prochnow, A; Yick, S; Bilek, M M M; Kondyurin, A; Han, Z J; Fang, J; Cvelbar, U; Mariotti, D; Ostrikov, K

    2015-12-01

    Mankind faces several global challenges such as chronic and acute hunger, global poverty, energy deficiency and environment conservation. Common biotechnologies based on batch, fluidbed and other similar processes are now extensively used for the production of a wide range of products such as antibiotics, biofuels, cultured and fermented food products. Unfortunately, these processes suffer from low efficiency, high energy demand, low controllability and rapid biocatalyst degradation by microbiological attack, and thus still are not capable of seriously addressing the global hunger and energy deficiency challenges. Moreover, sustainable future technologies require minimizing the environmental impact of toxic by-products by implementing the "life produces organic matter, organic matter sustains life" principle. Nanostructure-based biotechnology is one of the most promising approaches that can help to solve these challenges. In this work we briefly review the unique features of the carbon-based nanostructured platforms, with some attention paid to other nanomaterials. We discuss the main building blocks and processes to design and fabricate novel platforms, with a focus on dense arrays of the vertically-aligned nanostructures, mainly carbon nanotubes and graphene. Advantages and disadvantages of these systems are considered. PMID:26682454

  1. Carbon nanotube transistor based high-frequency electronics

    Science.gov (United States)

    Schroter, Michael

    At the nanoscale carbon nanotubes (CNTs) have higher carrier mobility and carrier velocity than most incumbent semiconductors. Thus CNT based field-effect transistors (FETs) are being considered as strong candidates for replacing existing MOSFETs in digital applications. In addition, the predicted high intrinsic transit frequency and the more recent finding of ways to achieve highly linear transfer characteristics have inspired investigations on analog high-frequency (HF) applications. High linearity is extremely valuable for an energy efficient usage of the frequency spectrum, particularly in mobile communications. Compared to digital applications, the much more relaxed constraints for CNT placement and lithography combined with already achieved operating frequencies of at least 10 GHz for fabricated devices make an early entry in the low GHz HF market more feasible than in large-scale digital circuits. Such a market entry would be extremely beneficial for funding the development of production CNTFET based process technology. This talk will provide an overview on the present status and feasibility of HF CNTFET technology will be given from an engineering point of view, including device modeling, experimental results, and existing roadblocks. Carbon nanotube transistor based high-frequency electronics.

  2. Carbonic anhydrase 5 regulates acid-base homeostasis in zebrafish.

    Directory of Open Access Journals (Sweden)

    Ruben Postel

    Full Text Available The regulation of the acid-base balance in cells is essential for proper cellular homeostasis. Disturbed acid-base balance directly affects cellular physiology, which often results in various pathological conditions. In every living organism, the protein family of carbonic anhydrases regulate a broad variety of homeostatic processes. Here we describe the identification, mapping and cloning of a zebrafish carbonic anhydrase 5 (ca5 mutation, collapse of fins (cof, which causes initially a collapse of the medial fins followed by necrosis and rapid degeneration of the embryo. These phenotypical characteristics can be mimicked in wild-type embryos by acetazolamide treatment, suggesting that CA5 activity in zebrafish is essential for a proper development. In addition we show that CA5 regulates acid-base balance during embryonic development, since lowering the pH can compensate for the loss of CA5 activity. Identification of selective modulators of CA5 activity could have a major impact on the development of new therapeutics involved in the treatment of a variety of disorders.

  3. CMOS considerations in nanoelectromechanical carbon nanotube-based switches

    Energy Technology Data Exchange (ETDEWEB)

    Yousif, M Y A; Lundgren, P; Ghavanini, F; Enoksson, P; Bengtsson, S [Micro- and Nanosystems Group, BioNano Systems Laboratory, Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-412 96 Gothenburg (Sweden)

    2008-07-16

    In this paper, we focus on critical issues directly related to the viability of carbon nanotube-based nanoelectromechanical switches, to perform their intended functionality as logic and memory elements, through assessment of typical performance parameters with reference to complementary metal-oxide-semiconductor devices. A detailed analysis of performance metrics regarding threshold voltage control, static and dynamic power dissipation, speed, and integration density is presented. Apart from packaging and reliability issues, these switches seem to be competitive in low power, particularly low-standby power, logic and memory applications.

  4. CMOS considerations in nanoelectromechanical carbon nanotube-based switches

    Science.gov (United States)

    Yousif, M. Y. A.; Lundgren, P.; Ghavanini, F.; Enoksson, P.; Bengtsson, S.

    2008-07-01

    In this paper, we focus on critical issues directly related to the viability of carbon nanotube-based nanoelectromechanical switches, to perform their intended functionality as logic and memory elements, through assessment of typical performance parameters with reference to complementary metal-oxide-semiconductor devices. A detailed analysis of performance metrics regarding threshold voltage control, static and dynamic power dissipation, speed, and integration density is presented. Apart from packaging and reliability issues, these switches seem to be competitive in low power, particularly low-standby power, logic and memory applications.

  5. Gas Sensors Based on Coated and Doped Carbon Nanotubes

    Science.gov (United States)

    Li, Jing; Meyyappan, Meyya

    2008-01-01

    Efforts are underway to develop inexpensive, low-power electronic sensors, based on single-walled carbon nanotubes (SWCNTs), for measuring part-per-million and part-per-billion of selected gases (small molecules) at room temperature. Chemically unmodified SWCNTs are mostly unresponsive to typical gases that one might wish to detect. However, the electrical resistances of SWCNTs can be made to vary with concentrations of gases of interest by coating or doping the SWCNTs with suitable materials. Accordingly, the basic idea of the present development efforts is to incorporate thus-treated SWCNTs into electronic devices that measure their electrical resistances.

  6. Novel gas sensors based on carbon nanotube networks

    Energy Technology Data Exchange (ETDEWEB)

    Sayago, I; Aleixandre, M; Horrillo, M C; Fernandez, M J; Gutierrez, J [Laboratorio de Sensores IFA-CSIC, Serrano 144, 28006 Madrid (Spain); Terrado, E; Lafuente, E; Maser, W K; Benito, A M; Martinez, M T; Munoz, E [Instituto de CarboquImica CSIC, Miguel Luesma Castan 4, 50018 Zaragoza (Spain); Urriolabeitia, E P; Navarro, R [Departamento de Quimica Inorganica, ICMA (Universidad de Zaragoza-CSIC), 50009 Zaragoza (Spain)], E-mail: sayago@ifa.cetef.csic.es, E-mail: edgar@icb.csic.es

    2008-08-15

    Novel resistive gas sensors based on single-walled carbon nanotube (SWNT) networks as the active sensing element nave been investigated for gas detection. SWNTs networks were fabricated by airbrushing on alumina substrates. As-produced- and Pd-decorated SWNT materials were used as sensitive layers for the detection of NO{sub 2} and H{sub 2}, respectively. The studied sensors provided good response to NO{sub 2} and H{sub 2} as well as excellent selectivities to interfering gases.

  7. Laser-induced production of large carbon-based toroids

    International Nuclear Information System (INIS)

    We report on the production of large carbon-based toroids (CBTs) from fullerenes. The process involves two-step laser irradiation of a mixed fullerene target (76% C60, 22% C70). Transmission electron microscopy (TEM) clearly identifies toroidal-shaped structures as well as Q-shaped constructs. The typical diameters of the CBTs are ∼0.2-0.3 μm with tubular diameters of ∼50-100 nm, but toroids as wide as 0.5 μm are observed making them nanostructures on the verge of being microstructures

  8. Graphene-Based Carbon Materials for Electrochemical Energy Storage

    Directory of Open Access Journals (Sweden)

    Fei Liu

    2013-01-01

    Full Text Available Because of their unique 2D structure and numerous fascinating properties, graphene-based materials have attracted particular attention for their potential applications in energy storage devices. In this review paper, we focus on the latest work regarding the development of electrode materials for batteries and supercapacitors from graphene and graphene-based carbon materials. To begin, the advantages of graphene as an electrode material and the existing problems facing its use in this application will be discussed. The next several sections deal with three different methods for improving the energy storage performance of graphene: the restacking of the nanosheets, the doping of graphene with other elements, and the creation of defects on graphene planes. State-of-the-art work is reviewed. Finally, the prospects and further developments in the field of graphene-based materials for electrochemical energy storage are discussed.

  9. EUD-based biological optimization for carbon ion therapy

    Energy Technology Data Exchange (ETDEWEB)

    Brüningk, Sarah C., E-mail: sarah.brueningk@icr.ac.uk; Kamp, Florian; Wilkens, Jan J. [Department of Radiation Oncology, Technische Universität München, Klinikum rechts der Isar, Ismaninger Str. 22, München 81675, Germany and Physik-Department, Technische Universität München, James-Franck-Str. 1, Garching 85748 (Germany)

    2015-11-15

    Purpose: Treatment planning for carbon ion therapy requires an accurate modeling of the biological response of each tissue to estimate the clinical outcome of a treatment. The relative biological effectiveness (RBE) accounts for this biological response on a cellular level but does not refer to the actual impact on the organ as a whole. For photon therapy, the concept of equivalent uniform dose (EUD) represents a simple model to take the organ response into account, yet so far no formulation of EUD has been reported that is suitable to carbon ion therapy. The authors introduce the concept of an equivalent uniform effect (EUE) that is directly applicable to both ion and photon therapies and exemplarily implemented it as a basis for biological treatment plan optimization for carbon ion therapy. Methods: In addition to a classical EUD concept, which calculates a generalized mean over the RBE-weighted dose distribution, the authors propose the EUE to simplify the optimization process of carbon ion therapy plans. The EUE is defined as the biologically equivalent uniform effect that yields the same probability of injury as the inhomogeneous effect distribution in an organ. Its mathematical formulation is based on the generalized mean effect using an effect-volume parameter to account for different organ architectures and is thus independent of a reference radiation. For both EUD concepts, quadratic and logistic objective functions are implemented into a research treatment planning system. A flexible implementation allows choosing for each structure between biological effect constraints per voxel and EUD constraints per structure. Exemplary treatment plans are calculated for a head-and-neck patient for multiple combinations of objective functions and optimization parameters. Results: Treatment plans optimized using an EUE-based objective function were comparable to those optimized with an RBE-weighted EUD-based approach. In agreement with previous results from photon

  10. Carbon-based composite electrocatalysts for low temperature fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Popov, Branko N. (Columbia, SC); Lee, Jog-Won (Columbia, SC); Subramanian, Nalini P. (Kennesaw, GA); Kumaraguru, Swaminatha P. (Honeoye Falls, NY); Colon-Mercado, Hector R. (Columbia, SC); Nallathambi, Vijayadurga (T-Nagar, IN); Li, Xuguang (Columbia, SC); Wu, Gang (West Columbia, SC)

    2009-12-08

    A process for synthesis of a catalyst is provided. The process includes providing a carbon precursor material, oxidizing the carbon precursor material whereby an oxygen functional group is introduced into the carbon precursor material, and adding a nitrogen functional group into the oxidized carbon precursor material.

  11. Synthesis of the Carbon Nanomaterials Based on Renewable Bioresources

    Directory of Open Access Journals (Sweden)

    N.A. Chan

    2014-07-01

    Full Text Available The effectiveness and feasibility of producing nanoscale carbon materials from renewable bioresources were shown as an example marsh mass. The mechanisms of synthesis of amorphous organic carbon from sphagnum moss species modified by a liquid peat phase of humic nature are discussed. A fundamentally new way of producing carbon nanotubes by mechanical activation of amorphous organic carbon is described.

  12. A proposed model of the response of the anophthalmic socket to prosthetic eye wear and its application to the management of mucoid discharge.

    Science.gov (United States)

    Pine, Keith R; Sloan, Brian H; Jacobs, Robert J

    2013-08-01

    Mucoid discharge associated with prosthetic eye wear can be a distressing condition that affects the quality of life of people who have lost an eye. Discharge is the second highest concern of experienced prosthetic eye wearers after health of the companion eye and is prevalent in anophthalmic populations. Specific causes of mucoid discharge such as infections and environmental allergens are well understood, but non-specific causes are unknown and an evidence based protocol for managing non-specific discharge is lacking. Current management is based on prosthesis removal and cleaning, and professional re-polishing of the prosthesis. Tear protein deposits accumulate on prosthetic eyes. These deposits mediate the response of the socket to prosthetic eye wear and their influence (good and bad) is determined by differing cleaning regimes and standards of surface finish. This paper proposes a three-phase model that describes the response of the socket to prosthetic eye wear. The phases are: An initial period of wear of a new (or newly-polished) prosthesis when homeostasis is being established (or re-established) within the socket; a second period (equilibrium phase) where beneficial surface deposits have built up on the prosthesis and wear is safe and comfortable, and a third period (breakdown phase) where there is an increasing likelihood of harm from continued wear. The proposed model provides a rationale for a personal cleaning regime to manage non-specific mucoid discharge. Professional care of prosthetic eyes is also important for the management of discharge and evidence for effective surface finishing is reported in this study. Taken together, the proposed regimes for personal and professional care comprise a protocol for managing discharge associated with prosthetic eye wear. The protocol describes prosthetic eye cleaning methods and frequency, and suggests minimum standards for professional polishing. If confirmed, the protocol has the potential to resolve the

  13. Titanium-based zeolitic imidazolate framework for chemical fixation of carbon dioxide

    Science.gov (United States)

    A titanium-based zeolitic imidazolate framework (Ti-ZIF) with high surface area and porous morphology was synthesized and itsefficacy was demonstrated in the synthesis of cyclic carbonates from epoxides and carbon dioxide.

  14. Research of System Building Basing on the Low Carbon Economy About Carbon Accounting for the Enterprise

    Directory of Open Access Journals (Sweden)

    Yao Liqiong

    2016-01-01

    Full Text Available As global warming has become truth, is developing as a new economic model, The new economic development model has given rise to an important branch of environmental accounting, namely carbon accounting. At first, this paper discusses the carbon accounting theoretical foundation comprehensively, and then analyzes the environment of the construction of the carbon accounting system. The focus of the article is to build enterprise carbon accounting system, it covers the confirmation and measurement, record and information disclosure of the enterprise carbon accounting on the way of low carbon economy, its core is the processing of carbon emission rights, information disclosure mode and content, etc.; The purpose of this paper is to build enterprise carbon accounting system which is suitable for China’s national conditions, in order to provide certain reference and theoretical support for the low carbon economy development of our country.

  15. Simulation of devices based on carbon nanotubes and graphene

    Science.gov (United States)

    Abramov, I. I.; Labunov, V. A.; Kolomejtseva, N. V.; Romanova, I. A.

    2014-12-01

    The simulation results of different devices based on carbon nanotubes (CNT) and graphene are described in the paper. The combined numerical model of hybrid integrated structures including resonant tunneling diode and field-effect transistor (RTD-FET) is proposed. Simulation of RTD-FET based on CNT of different types (chirality) was realized with the use of the developed model. The technique of express simulation of nanoradio based on CNT of the type I (based on only single CNT) and of the type II (hybrid radio) is developed. Proposed models can be used for calculation of nanoradio characteristics such as: 1) resonant frequency of CNT; 2) oscillation amplitude of CNT; 3) CNT IV-characteristics depending on different factors. Results of device simulation based on single-wall and multi-wall CNT are given in the paper. IV-characteristics of nanoscale resonant tunneling structure based on graphene-on-SiC were calculated. As well as it was investigated the influence of different parameters on the electrical characteristic of graphene-based nanostructures.

  16. Carbon contributions from roots in cotton based rotations

    Science.gov (United States)

    Tan, D. K. Y.; Hulugalle, N. R.

    2012-04-01

    Most research on the decline in soil organic carbon (SOC) stocks in Australian cotton farming systems has focussed on the inputs from above-ground crop residues, with contribution from roots being less studied. This paper aims to outline the contribution of cotton roots and roots of other crops to soil carbon stocks in furrow-irrigated Vertisols in several cotton (Gossypium hirsutum L.)-based rotations. Data was collected from cotton-based rotation systems: cotton monoculture, cotton-vetch (Vicia benghalensis) Roth.), cotton-wheat (Triticum aestivum L.), cotton-wheat-vetch, cotton-corn, corn-corn, cotton-sorghum (Sorghum bicolor L.) and from BollgardTM II (Bt) and non-Bt cotton. Land management systems were permanent beds, with or without standing stubble, and conventional tillage. Root growth in the surface 0.10 m was measured with the core-break method, and that in the 0.10 to 1.0 m depth with a minirhizotron and I-CAP image capture system. These measurements were used to derive root C added to soil through intra-seasonal root death (Clost), C in roots remaining at the end of season (Croot), and total root C added to soil (Ctotal = Croot + Clost). Ctotal in non-Bt cotton (Sicot 80RRF, 0.9 t C/ha/year) was higher than in Bt cotton (Sicot 80RRF, 0.6 t C/ha/year). Overall, Ctotal from cotton roots ranges between 0.5 to 5 t C/ha/year, with Clost contributing 25-70%. Ctotal was greater with vetch than with wheat and was in the order of vetch in cotton-wheat-vetch (5.1 t C/ha/year) > vetch in cotton-vetch (1.9 t C/ha/year) > wheat in cotton-wheat (1.6 t C/ha/year) = wheat in cotton-wheat-vetch (1.7 t C/ha/year). Intra-seasonal root mortality accounted for 12% of total root carbon in vetch and 36% in wheat. Average corn Ctotal with monoculture was 9.3 t/ha and with cotton-corn 5.0 t/ha. Ctotal averaged between both treatments was, thus, of the order of 7.7 t C/ha/year and average Clost 0.04 t/ha/yr. Sorghum roots contributed less carbon with conventional tillage (8.2 t

  17. Determining asymmetry of roll-over shapes in prosthetic walking

    NARCIS (Netherlands)

    Curtze, C.; Otten, B.; Hof, A.L.; Postema, K.

    2011-01-01

    How does the inherent asymmetry of the locomotor system in people with lower-limb amputation affect the ankle-foot roll-over shape of prosthetic walking? In a single-case design, we evaluated the walking patterns of six people with lower-limb amputation (3 transtibial and 3 transfemoral) and three m

  18. PROSTHETIC GAIT OF UNILATERAL TRANSFEMORAL AMPUTEES - A KINEMATIC STUDY

    NARCIS (Netherlands)

    JAEGERS, SMHJ; ARENDZEN, JH; DEJONGH, HJ

    1995-01-01

    Objective: The prosthetic gait of unilateral transfemoral amputees. Design: Case series. Setting: Laboratory of Gait Analysis (GIGA-system of K-lab) in the Department of Rehabilitation of a university hospital. Patients: Eleven men with transfemoral amputation (mean age 35.7 years) participated. The

  19. Prosthetic Hand For Holding Rods, Tools, And Handles

    Science.gov (United States)

    Belcher, Jewell G., Jr.; Vest, Thomas W.

    1995-01-01

    Prosthetic hand with quick-grip/quick-release lever broadens range of specialized functions available to lower-arm amputee by providing improved capabilities for gripping rods, tools, handles, and like. Includes two stationary lower fingers opposed by one pivoting upper finger. Lever operates in conjunction with attached bracket.

  20. Selective criteria for successful long-term prosthetic use.

    Science.gov (United States)

    Mueller, M J; Delitto, A

    1985-07-01

    The purpose of this study was to identify criteria contributing to successful long-term prosthetic use in patients with an amputation secondary to vascular disease. All elderly patients with a unilateral below-knee amputation or an above-knee amputation, secondary to vascular disease, seen in our clinic between 1977 and 1982 were included in this telephone survey. Of those contacted, 37 of 38 below-knee amputees (BKAs) and 7 of 18 above-knee amputees (AKAs) still wore their prostheses at least part of every day (success). We used a two-tailed chi-square to compare the success of the BKAs with the success of the AKAs. The BKAs were successful more often (X2 = 24.81, df = 1, p less than .001). All AKAs also were characterized according to age, time from prescription, obesity, ambulatory status, strength, range of motion, sex, general compliance, and medical problems after prosthetic prescription. Of these criteria, only compliance and medical problems after prescription showed a significant difference between successful and nonsuccessful long-term AKA prosthetic users (X2 = 5.76, df = 1, p less than .05 for each criterion). As the demands of quality assurance and diagnostic related groupings increase, these results can assist the physical therapy clinician in setting realistic goals for the geriatric amputee and help predict if the patient will be a successful prosthetic user.

  1. Development of a prototype over-actuated biomimetic prosthetic hand.

    Directory of Open Access Journals (Sweden)

    Matthew R Williams

    Full Text Available The loss of a hand can greatly affect quality of life. A prosthetic device that can mimic normal hand function is very important to physical and mental recuperation after hand amputation, but the currently available prosthetics do not fully meet the needs of the amputee community. Most prosthetic hands are not dexterous enough to grasp a variety of shaped objects, and those that are tend to be heavy, leading to discomfort while wearing the device. In order to attempt to better simulate human hand function, a dexterous hand was developed that uses an over-actuated mechanism to form grasp shape using intrinsic joint mounted motors in addition to a finger tendon to produce large flexion force for a tight grip. This novel actuation method allows the hand to use small actuators for grip shape formation, and the tendon to produce high grip strength. The hand was capable of producing fingertip flexion force suitable for most activities of daily living. In addition, it was able to produce a range of grasp shapes with natural, independent finger motion, and appearance similar to that of a human hand. The hand also had a mass distribution more similar to a natural forearm and hand compared to contemporary prosthetics due to the more proximal location of the heavier components of the system. This paper describes the design of the hand and controller, as well as the test results.

  2. Consumer satisfaction with the services of prosthetics and orthotics facilities

    NARCIS (Netherlands)

    Bosmans, Joline; Geertzen, Jan; Dijkstra, Pieter U.

    2009-01-01

    Consumer satisfaction with the services provided in a prosthetics and orthotics (PO) facility has seldom been studied. The aim of this study was to analyze consumer satisfaction regarding the services provided by 15 PO facilities in The Netherlands. Consumers (n=1,364) of these PO facilities who wer

  3. 21 CFR 890.3025 - Prosthetic and orthotic accessory.

    Science.gov (United States)

    2010-04-01

    ... intended for medical purposes to support, protect, or aid in the use of a cast, orthosis (brace), or prosthesis. Examples of prosthetic and orthotic accessories include the following: A pelvic support band and belt, a cast shoe, a cast bandage, a limb cover, a prosthesis alignment device, a postsurgical pylon,...

  4. Early prosthetic valve endocarditis caused by Corynebacterium kroppenstedtii.

    Science.gov (United States)

    Hagemann, Jürgen Benjamin; Essig, Andreas; Herrmann, Manuel; Liebold, Andreas; Quader, Mohamed Abo

    2015-12-01

    Corynebacterium (C.) kroppenstedtii is a rarely detected agent of bacterial infections in humans. Here, we describe the first case of prosthetic valve endocarditis caused by C. kroppenstedtii. Application of molecular methods using surgically excised valve tissue was a cornerstone for the establishment of the microbiological diagnosis, which is crucial for targeted antimicrobial treatment.

  5. Case report of Streptomyces endocarditis of a prosthetic aortic valve.

    Science.gov (United States)

    Mossad, S B; Tomford, J W; Stewart, R; Ratliff, N B; Hall, G S

    1995-01-01

    We describe the first case of prosthetic valve endocarditis due to a Streptomyces sp. The patient presented with fever, cutaneous embolic lesions, and bacteremia 3 months after aortic valve replacement. Treatment required valve replacement and a long course of parenteral imipenem. PMID:8586732

  6. Case report of Streptomyces endocarditis of a prosthetic aortic valve.

    OpenAIRE

    Mossad, S B; Tomford, J W; Stewart, R; Ratliff, N B; Hall, G. S.

    1995-01-01

    We describe the first case of prosthetic valve endocarditis due to a Streptomyces sp. The patient presented with fever, cutaneous embolic lesions, and bacteremia 3 months after aortic valve replacement. Treatment required valve replacement and a long course of parenteral imipenem.

  7. Design and Implementation of Prosthetic Arm using Gear Motor Control Technique with Appropriate Testing

    CERN Document Server

    Neogi, Biswarup; Ghosal, Soumya; Das, Achintya; Tibarewala, D N

    2011-01-01

    Any part of the human body replication procedure commences the prosthetic control science. This paper highlights the hardware design technique of a prosthetic arm with implementation of gear motor control aspect. The prosthetic control arm movement has been demonstrated in this paper applying processor programming and with the successful testing of the designed prosthetic model. The architectural design of the prosthetic arm here has been replaced by lighter material instead of heavy metal, as well as the traditional EMG (electro myographic) signal has been replaced by the muscle strain.

  8. Carbon Nanotube Based Chemical Sensors for Space and Terrestrial Applications

    Science.gov (United States)

    Li, Jing; Lu, Yijiang

    2009-01-01

    A nanosensor technology has been developed using nanostructures, such as single walled carbon nanotubes (SWNTs), on a pair of interdigitated electrodes (IDE) processed with a silicon-based microfabrication and micromachining technique. The IDE fingers were fabricated using photolithography and thin film metallization techniques. Both in-situ growth of nanostructure materials and casting of the nanostructure dispersions were used to make chemical sensing devices. These sensors have been exposed to nitrogen dioxide, acetone, benzene, nitrotoluene, chlorine, and ammonia in the concentration range of ppm to ppb at room temperature. The electronic molecular sensing of carbon nanotubes in our sensor platform can be understood by intra- and inter-tube electron modulation in terms of charge transfer mechanisms. As a result of the charge transfer, the conductance of p-type or hole-richer SWNTs in air will change. Due to the large surface area, low surface energy barrier and high thermal and mechanical stability, nanostructured chemical sensors potentially can offer higher sensitivity, lower power consumption and better robustness than the state-of-the-art systems, which make them more attractive for defense and space applications. Combined with MEMS technology, light weight and compact size sensors can be made in wafer scale with low cost. Additionally, a wireless capability of such a sensor chip can be used for networked mobile and fixed-site detection and warning systems for military bases, facilities and battlefield areas.

  9. The composites based on plasticized starch and carbon nanotubes.

    Science.gov (United States)

    Cheng, Jing; Zheng, Pengwu; Zhao, Feng; Ma, Xiaofei

    2013-08-01

    In this study, the nanocomposite films based on plasticized starch and modified-carbon nanotubes were prepared using a simple casting method. Carbon nanotubes (CNTs) were oxidized to prepare CNT oxide (OCNT) by Hummer's method, and OCNTs were reduced by glucose to obtain reduced CNT (RCNT). The thermogravimetric (TG) curves revealed that OCNTs and RCNTs contained about 15 and 8wt% oxygen-containing groups, respectively. The UV-vis spectra proved that CNTs with the aid of the dispersant TNWDIS, OCNTs and RCNTs possessed the good stability in water. As the fillers, CNTs, OCNTs and RCNTs were introduced into plasticized-starch (PS) matrix to obtain the composites. They had the obvious reinforcing effect on PS matrix. The composites containing 4wt% RCNT had the maximum tensile strength of 19.5MPa, in contrast to 3.89MPa of PS. Among of them, PS/CNT composites showed the best moisture resistance. And the PS-based CNT, OCNT and RCNT composites exhibited approximate electrical conductivities. PMID:23587994

  10. Heat Dissipation for Microprocessor Using Multiwalled Carbon Nanotubes Based Liquid

    Directory of Open Access Journals (Sweden)

    Bui Hung Thang

    2013-01-01

    Full Text Available Carbon nanotubes (CNTs are one of the most valuable materials with high thermal conductivity (2000 W/m·K compared with thermal conductivity of Ag 419 W/m·K. This suggested an approach in applying the CNTs in thermal dissipation system for high power electronic devices, such as computer processor and high brightness light emitting diode (HB-LED. In this work, multiwalled carbon nanotubes (MWCNTs based liquid was made by COOH functionalized MWCNTs dispersed in distilled water with concentration in the range between 0.2 and 1.2 gram/liter. MWCNT based liquid was used in liquid cooling system to enhance thermal dissipation for computer processor. By using distilled water in liquid cooling system, CPU’s temperature decreases by about 10°C compared with using fan cooling system. By using MWCNT liquid with concentration of 1 gram/liter MWCNTs, the CPU’s temperature decreases by 7°C compared with using distilled water in cooling system. Theoretically, we also showed that the presence of MWCNTs reduced thermal resistance and increased the thermal conductivity of liquid cooling system. The results have confirmed the advantages of the MWCNTs for thermal dissipation systems for the μ-processor and other high power electronic devices.

  11. Heat dissipation for microprocessor using multiwalled carbon nanotubes based liquid.

    Science.gov (United States)

    Hung Thang, Bui; Trinh, Pham Van; Chuc, Nguyen Van; Khoi, Phan Hong; Minh, Phan Ngoc

    2013-01-01

    Carbon nanotubes (CNTs) are one of the most valuable materials with high thermal conductivity (2000 W/m · K compared with thermal conductivity of Ag 419 W/m · K). This suggested an approach in applying the CNTs in thermal dissipation system for high power electronic devices, such as computer processor and high brightness light emitting diode (HB-LED). In this work, multiwalled carbon nanotubes (MWCNTs) based liquid was made by COOH functionalized MWCNTs dispersed in distilled water with concentration in the range between 0.2 and 1.2 gram/liter. MWCNT based liquid was used in liquid cooling system to enhance thermal dissipation for computer processor. By using distilled water in liquid cooling system, CPU's temperature decreases by about 10°C compared with using fan cooling system. By using MWCNT liquid with concentration of 1 gram/liter MWCNTs, the CPU's temperature decreases by 7°C compared with using distilled water in cooling system. Theoretically, we also showed that the presence of MWCNTs reduced thermal resistance and increased the thermal conductivity of liquid cooling system. The results have confirmed the advantages of the MWCNTs for thermal dissipation systems for the μ -processor and other high power electronic devices.

  12. Significant Performance Enhancement in Asymmetric Supercapacitors based on Metal Oxides, Carbon nanotubes and Neutral Aqueous Electrolyte

    OpenAIRE

    Arvinder Singh; Amreesh Chandra

    2015-01-01

    Amongst the materials being investigated for supercapacitor electrodes, carbon based materials are most investigated. However, pure carbon materials suffer from inherent physical processes which limit the maximum specific energy and power that can be achieved in an energy storage device. Therefore, use of carbon-based composites with suitable nano-materials is attaining prominence. The synergistic effect between the pseudocapacitive nanomaterials (high specific energy) and carbon (high specif...

  13. Fe-catalyzed carbon nanotubes for high-energy density carbon-based supercapacitors

    Science.gov (United States)

    Emmett, Robert; Karakaya, Mehmet; Roberts, Mark; Arcilla-Velez, Margarita; Podila, Ramakrishna; Rao, Apparao

    2014-03-01

    Carbon nanotubes (CNTs) are one of the most suitable supercapacitor electrode materials due to their high mechanical strength, electrical conductivity, and surface area. Albeit these unique properties of CNTs, energy density of carbon-based double layer capacitors is limited by the inability of CNTs to actively participate in redox processes. Here, we show that electrochemical characteristics of CNTs can be improved by activating the residual Fe catalyst to participate in Faradaic charge storage via Fe2+ ->Fe3+ redox process. By using traditional liquid injection chemical vapor deposited CNTs which contains 5.7 wt.% residual Fe catalyst (R. Andrews et al.,, Chem. Phys. Letters, 303, 467-474 (1999)), the capacitance of CNT electrodes can be increased from 20 F/g to 150 F/g, in the range of -0.2 to 1.2 V. The use of Fe containing CNTs to manufacture supercapacitor electrodes with increased energy density and charge capacity of with high charge/discharge rates with extremely long-term cycle stability will be discussed. Research supported by US NSF CMMI Grant1246800.

  14. Electroadsorption Desalination with Carbon Nanotube/PAN-Based Carbon Fiber Felt Composites as Electrodes

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2014-01-01

    Full Text Available The chemical vapor deposition method is used to prepare CNT (carbon nanotube/PCF (PAN-based carbon fiber felt composite electrodes in this paper, with the surface morphology of CNT/PCF composites and electroadsorption desalination performance being studied. Results show such electrode materials with three-dimensional network nanostructures having a larger specific surface area and narrower micropore distribution, with a huge number of reactive groups covering the surface. Compared with PCF electrodes, CNT/PCF can allow for a higher adsorption and desorption rate but lower energy consumption; meanwhile, under the condition of the same voltage change, the CNT/PCF electrodes are provided with a better desalination effect. The study also found that the higher the original concentration of the solution, the greater the adsorption capacity and the lower the adsorption rate. At the same time, the higher the solution’s pH, the better the desalting; the smaller the ions’ radius, the greater the amount of adsorption.

  15. Lyocell Based Carbon Carbon Composite for Use as a Large Exit Cone Material Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA Office of the Chief Technologist (OCT) has identified a "carbon-carbon nozzle (domestic source)" as a "Top Technical Challenge" in the 2011-2016 timeframe...

  16. Research of System Building Basing on the Low Carbon Economy About Carbon Accounting for the Enterprise

    OpenAIRE

    Yao Liqiong

    2016-01-01

    As global warming has become truth, is developing as a new economic model, The new economic development model has given rise to an important branch of environmental accounting, namely carbon accounting. At first, this paper discusses the carbon accounting theoretical foundation comprehensively, and then analyzes the environment of the construction of the carbon accounting system. The focus of the article is to build enterprise carbon accounting system, it covers the confirmation and measureme...

  17. Synthesis of polybenzoxazine based nitrogen-rich porous carbons for carbon dioxide capture

    Science.gov (United States)

    Wan, Liu; Wang, Jianlong; Feng, Chong; Sun, Yahui; Li, Kaixi

    2015-04-01

    Nitrogen-rich porous carbons (NPCs) were synthesized from 1,5-dihydroxynaphthalene, urea, and formaldehyde based on benzoxazine chemistry by a soft-templating method with KOH chemical activation. They possess high surface areas of 856.8-1257.8 m2 g-1, a large pore volume of 0.15-0.65 cm3 g-1, tunable pore structure, high nitrogen content (5.21-5.32 wt%), and high char yields. The amount of the soft-templating agent F127 has multiple influences on the textural and chemical properties of the carbons, affecting the surface area and pore structure, impacting the compositions of nitrogen species and resulting in an improvement of the CO2 capture performance. At 1 bar, high CO2 uptake of 4.02 and 6.35 mmol g-1 at 25 and 0 °C was achieved for the sample NPC-2 with a molar ratio of F127 : urea = 0.010 : 1. This can be attributed to its well-developed micropore structure and abundant pyridinic nitrogen, pyrrolic nitrogen and pyridonic nitrogen functionalities. The sample NPC-2 also exhibits a remarkable selectivity for CO2/N2 separation and a fast adsorption/desorption rate and can be easily regenerated. This suggests that the polybenzoxazine-based NPCs are desirable for CO2 capture because of possessing a high micropore surface area, a large micropore volume, appropriate pore size distribution, and a large number of basic nitrogen functionalities.Nitrogen-rich porous carbons (NPCs) were synthesized from 1,5-dihydroxynaphthalene, urea, and formaldehyde based on benzoxazine chemistry by a soft-templating method with KOH chemical activation. They possess high surface areas of 856.8-1257.8 m2 g-1, a large pore volume of 0.15-0.65 cm3 g-1, tunable pore structure, high nitrogen content (5.21-5.32 wt%), and high char yields. The amount of the soft-templating agent F127 has multiple influences on the textural and chemical properties of the carbons, affecting the surface area and pore structure, impacting the compositions of nitrogen species and resulting in an improvement of the

  18. A glucose biosensor based on partially unzipped carbon nanotubes.

    Science.gov (United States)

    Hu, Huifang; Feng, Miao; Zhan, Hongbing

    2015-08-15

    An amperometric glucose biosensor based on direct electron transfer of glucose oxidase (GOD) self-assembled on the surface of partially unzipped carbon nanotubes (PUCNTs) modified glassy carbon electrode (GCE) has been successfully fabricated. PUCNTs were synthesized via a facile chemical oxidative etching CNTs and used as a novel immobilization matrix for GOD. The cyclic voltammetric result of the PUCNT/GOD/GCE showed a pair of well-defined and quasi-reversible redox peaks with a formal potential of -0.470V and a peak to peak separation of 37mV, revealing that the fast direct electron transfer between GOD and the electrode has been achieved. It is notable that the glucose determination has been achieved in mediator-free condition. The developed biosensor displayed satisfactory analytical performance toward glucose including high sensitivity (19.50μA mM(-1)cm(-2)), low apparent Michaelis-Menten (5.09mM), a wide linear range of 0-17mM, and also preventing the interference from ascorbic acid, uric acid and dopamine usually coexisting with glucose in human blood. In addition, the biosensor acquired excellent storage stabilities. This facile, fast, environment-friendly and economical preparation strategy of PUCNT-GOD may provide a new platform for the fabrication of biocompatible glucose biosensors and other types of biosensors. PMID:25966382

  19. Recent advances in molecular electronics based on carbon nanotubes.

    Science.gov (United States)

    Bourgoin, Jean-Philippe; Campidelli, Stéphane; Chenevier, Pascale; Derycke, Vincent; Filoramo, Arianna; Goffman, Marcelo F

    2010-01-01

    Carbon nanotubes (CNTs) have exceptional physical properties that make them one of the most promising building blocks for future nanotechnologies. They may in particular play an important role in the development of innovative electronic devices in the fields of flexible electronics, ultra-high sensitivity sensors, high frequency electronics, opto-electronics, energy sources and nano-electromechanical systems (NEMS). Proofs of concept of several high performance devices already exist, usually at the single device level, but there remain many serious scientific issues to be solved before the viability of such routes can be evaluated. In particular, the main concern regards the controlled synthesis and positioning of nanotubes. In our opinion, truly innovative use of these nano-objects will come from: (i) the combination of some of their complementary physical properties, such as combining their electrical and mechanical properties, (ii) the combination of their properties with additional benefits coming from other molecules grafted on the nanotubes, and (iii) the use of chemically- or bio-directed self-assembly processes to allow the efficient combination of several devices into functional arrays or circuits. In this article, we outline the main issues concerning the development of carbon nanotubes based electronics applications and review our recent results in the field.

  20. Self-Monitoring Strengthening System Based on Carbon Fiber Laminate

    Directory of Open Access Journals (Sweden)

    Rafal Krzywon

    2016-01-01

    Full Text Available Externally bonded composites reinforced with high-strength fibers are increasingly popular in construction, especially in structures’ strengthening, where the best possible mechanical properties are required. At the same time the ability to autodetect threats is one of the most desirable features of contemporary structures. The authors of the paper have developed an intelligent fabric, wherein the carbon fibers play the role of not only tensile reinforcement but also strain sensor. The idea is based on the construction of the strain gauge, where the thread of carbon fibers arranged in zig-zag pattern works as electrical conductor and is insulated by parallel thread of glass or acrylic fibers. Preliminary laboratory tests were designed to create effective measurement techniques and assess the effectiveness of the strengthening of selected building structures, as reinforced concrete and timber beams. Presented in the paper, selected results of these studies are very promising, although there were some noted problems to be considered in next steps. The main problem here is the control of the cross section of the fibers tow, affecting the total resistance of the fabric. One of the main deficiencies of the proposed solution is also sensitivity to moisture.

  1. A Review: Carbon Nanotube-Based Piezoresistive Strain Sensors

    Directory of Open Access Journals (Sweden)

    Waris Obitayo

    2012-01-01

    Full Text Available The use of carbon nanotubes for piezoresistive strain sensors has acquired significant attention due to its unique electromechanical properties. In this comprehensive review paper, we discussed some important aspects of carbon nanotubes for strain sensing at both the nanoscale and macroscale. Carbon nanotubes undergo changes in their band structures when subjected to mechanical deformations. This phenomenon makes them applicable for strain sensing applications. This paper signifies the type of carbon nanotubes best suitable for piezoresistive strain sensors. The electrical resistivities of carbon nanotube thin film increase linearly with strain, making it an ideal material for a piezoresistive strain sensor. Carbon nanotube composite films, which are usually fabricated by mixing small amounts of single-walled or multiwalled carbon nanotubes with selected polymers, have shown promising characteristics of piezoresistive strain sensors. Studies also show that carbon nanotubes display a stable and predictable voltage response as a function of temperature.

  2. Possibility of magnetic resonance imaging application in teaching preclinical dentistry - endodontic and prosthetic treatment prognosis

    International Nuclear Information System (INIS)

    Background. The necessary condition for successful both endodontic and prosthetic reconstruction treatment is the precise mapping of the shape of dental cavities. The aim of this work is an elaboration and verification of the possibility of using 3D Spin Echo MRI techniques in teaching preclinical dentistry both in endodontic and prosthetics specialty. Objectives. Author' aim was to obtain an elaboration and a verification, whether there exists a possibility to use, at the level of in vitro analysis, techniques of the Magnetic Resonance Imaging, which are based on the 3D sequence of the Spin Echo that may in the future find employment in the teaching of preclinical dentistry, clinical dental therapy and diagnostics within the scope of: a dimensional imaging of the inner topography of teeth and spatial structure of a chamber and root canals of teeth for the therapeutic and didactic aims; introduction of a nondestructive and a non-impressional method of reconstruction of the topography of the inner spaces of the human teeth for the purposes of the reconstructive dentistry. Material and Methods. 6 extracted molar teeth were used for measurements without additional preparation, after endodontic and prosthetic preparation. MR measurements were carried out on a 4.7 T research MRI system equipped with Maran DRX console. Results. Figures show 3D images of outer surface, inner space of the teeth before and after endodontic preparation and internal tooth fixation constructed using both classical methods (polymer mass impression) and non-impressional methods (MRI representation). The sizes of the presented volumes were calculated. Internal tooth volumes were determined before and after endodontic treatment; total tooth volumes were also measured. Research proceedings made it possible to compare the quality of internal tooth space after preparation for inner root canals fixations constructed using both classical methods and non-impressional MRI method. Conclusions. The results

  3. Effects of Salivary Oxidative Markers on Edentulous Patients' Satisfaction with Prosthetic Denture Treatments: A Pilot Study.

    Directory of Open Access Journals (Sweden)

    Chia-Huang Chang

    Full Text Available The purpose of this study was to assess relationships among periodontal conditions, salivary antioxidant levels, and patients' satisfaction with their prostheses.This study was conducted at the Division of Prosthodontics, Department of Dentistry, Taipei Medical University Hospital. The periodontal condition of patients was based on an assessment of the plaque index (PI and gingival index (GI. The pH value, flow rate, and buffer capacity of the saliva were estimated. The salivary total antioxidant status (TAS and superoxide dismutase (SOD level were also determined. Patients' satisfaction with prosthetic treatments was evaluated using the Chinese version of the short-form Oral Health Impact Profile (OHIP-14C. A multivariate regression model was used to determine whether patients' satisfaction with prosthetic treatment was affected by their oral health status.In total, 35 edentulous patients were recruited. In the Spearman correlation analysis, salivary pH (r = -0.36, p = 0.03 and the buffer ability (r = -0.48, p<0.01 were associated with OHIP-14C scores. In the multivariate analysis, patients who had a higher GI also had a higher score of physical disabilities (β = 1.38, p = 0.04. Levels of SOD increased with the scores of psychological discomfort (β = 0.33 U/g protein, p = 0.04.This study suggested that both the GI and SOD levels were associated with patients' satisfaction with prosthetic treatments. To the best of our knowledge, this is the first study to elucidate the relationship between OHIP scores and salivary oxidative markers in edentulous patients.

  4. Carbon carry capacity and carbon sequestration potential in China based on an integrated analysis of mature forest biomass.

    Science.gov (United States)

    Liu, YingChun; Yu, GuiRui; Wang, QiuFeng; Zhang, YangJian; Xu, ZeHong

    2014-12-01

    Forests play an important role in acting as a carbon sink of terrestrial ecosystem. Although global forests have huge carbon carrying capacity (CCC) and carbon sequestration potential (CSP), there were few quantification reports on Chinese forests. We collected and compiled a forest biomass dataset of China, a total of 5841 sites, based on forest inventory and literature search results. From the dataset we extracted 338 sites with forests aged over 80 years, a threshold for defining mature forest, to establish the mature forest biomass dataset. After analyzing the spatial pattern of the carbon density of Chinese mature forests and its controlling factors, we used carbon density of mature forests as the reference level, and conservatively estimated the CCC of the forests in China by interpolation methods of Regression Kriging, Inverse Distance Weighted and Partial Thin Plate Smoothing Spline. Combining with the sixth National Forest Resources Inventory, we also estimated the forest CSP. The results revealed positive relationships between carbon density of mature forests and temperature, precipitation and stand age, and the horizontal and elevational patterns of carbon density of mature forests can be well predicted by temperature and precipitation. The total CCC and CSP of the existing forests are 19.87 and 13.86 Pg C, respectively. Subtropical forests would have more CCC and CSP than other biomes. Consequently, relying on forests to uptake carbon by decreasing disturbance on forests would be an alternative approach for mitigating greenhouse gas concentration effects besides afforestation and reforestation.

  5. Prosthetic hand sensor placement: Analysis of touch perception during the grasp

    Directory of Open Access Journals (Sweden)

    Mirković Bojana

    2014-01-01

    Full Text Available Humans rely on their hands to perform everyday tasks. The hand is used as a tool, but also as the interface to “sense” the world. Current prosthetic hands are based on sophisticated multi-fingered structures, and include many sensors which counterpart natural proprioceptors and exteroceptors. The sensory information is used for control, but not sent to the user of the hand (amputee. Grasping without sensing is not good enough. This research is part of the development of the sensing interface for amputees, specifically addressing the analysis of human perception while grasping. The goal is to determine the small number of preferred positions of sensors on the prosthetic hand. This task has previously been approached by trying to replicate a natural sensory system characteristic for healthy humans, resulting in a multitude of redundant sensors and basic inability to make the patient aware of the sensor readings on the subconscious level. We based our artificial perception system on the reported sensations of humans when grasping various objects without seeing the objects (obstructed visual feedback. Subjects, with no known sensory deficits, were asked to report on the touch sensation while grasping. The analysis included objects of various sizes, weights, textures and temperatures. Based on this data we formed a map of the preferred positions for the sensors that is appropriate for five finger human-like robotic hand. The final map was intentionally minimized in size (number of sensors.

  6. Analysis of carbon based materials under fusion relevant thermal loads

    International Nuclear Information System (INIS)

    Carbon based materials (CBMs) are used in fusion devices as plasma facing materials for decades. They have been selected due to the inherent advantages of carbon for fusion applications. The main ones are its low atomic number and the fact that it does not melt but sublimate (above 3000 C) under the planned working conditions. In addition, graphitic materials retain their mechanical properties at elevated temperatures and their thermal shock resistance is one of the highest, making them suitable for thermal management purpose during long or extremely short heat pulses. Nuclear grade fine grain graphite was the prime form of CBM which was set as a standard but when it comes to large fusion devices created nowadays, thermo-mechanical constraints created during transient heat loads (few GW.m-2 can be deposited in few ms) are so high that carbon/carbon composites (so-called Carbon Fiber Composites (CFCs)) have to be utilized. CFCs can achieve superior thermal conductivity as well as mechanical properties than fine grain graphite. However, all the thermo-mechanical properties of CFCs are highly dependent on the loading direction as a consequence of the graphite structure. In this work, the background on the anisotropy of the graphitic structures but also on the production of fine grain graphite and CFCs is highlighted, showing the major principles which are relevant for the further understanding of the study. Nine advanced CBMs were then compared in terms of microstructure and thermo-mechanical properties. Among them, two fine grain graphites were considered as useful reference materials to allow comparing advantages reached by the developed CFCs. The presented microstructural investigation methods permitted to make statements which can be applied for CFCs presenting similarities in terms of fiber architecture. Determination of the volumetric percentage of the major sub-units of CFCs, i.e. laminates, felt layers or needled fiber groups, lead to a better understanding on

  7. Carbon Nanotube Based Groundwater Remediation: The Case of Trichloroethylene.

    Science.gov (United States)

    Jha, Kshitij C; Liu, Zhuonan; Vijwani, Hema; Nadagouda, Mallikarjuna; Mukhopadhyay, Sharmila M; Tsige, Mesfin

    2016-01-01

    Adsorption of chlorinated organic contaminants (COCs) on carbon nanotubes (CNTs) has been gaining ground as a remedial platform for groundwater treatment. Applications depend on our mechanistic understanding of COC adsorption on CNTs. This paper lays out the nature of competing interactions at play in hybrid, membrane, and pure CNT based systems and presents results with the perspective of existing gaps in design strategies. First, current remediation approaches to trichloroethylene (TCE), the most ubiquitous of the COCs, is presented along with examination of forces contributing to adsorption of analogous contaminants at the molecular level. Second, we present results on TCE adsorption and remediation on pure and hybrid CNT systems with a stress on the specific nature of substrate and molecular architecture that would contribute to competitive adsorption. The delineation of intermolecular interactions that contribute to efficient remediation is needed for custom, scalable field design of purification systems for a wide range of contaminants. PMID:27455218

  8. A carbon nanotube based ammonia sensor on cotton textile

    Science.gov (United States)

    Han, Jin-Woo; Kim, Beomseok; Li, Jing; Meyyappan, M.

    2013-05-01

    A single-wall carbon nanotube (CNT) based ammonia (NH3) sensor was implemented on a cotton yarn. Two types of sensors were fabricated: Au/sensing CNT/Au and conducting/sensing/conducting all CNT structures. Two perpendicular Au wires were designed to contact CNT-cotton yarn for metal-CNT sensor, whereas nanotubes were used for the electrode as well as sensing material for the all CNT sensor. The resistance shift of the CNT network upon NH3 was monitored in a chemiresistor approach. The CNT-cotton yarn sensors exhibited uniformity and repeatability. Furthermore, the sensors displayed good mechanical robustness against bending. The present approach can be utilized for low-cost smart textile applications.

  9. Carbon Nanotube Based Groundwater Remediation: The Case of Trichloroethylene

    Directory of Open Access Journals (Sweden)

    Kshitij C. Jha

    2016-07-01

    Full Text Available Adsorption of chlorinated organic contaminants (COCs on carbon nanotubes (CNTs has been gaining ground as a remedial platform for groundwater treatment. Applications depend on our mechanistic understanding of COC adsorption on CNTs. This paper lays out the nature of competing interactions at play in hybrid, membrane, and pure CNT based systems and presents results with the perspective of existing gaps in design strategies. First, current remediation approaches to trichloroethylene (TCE, the most ubiquitous of the COCs, is presented along with examination of forces contributing to adsorption of analogous contaminants at the molecular level. Second, we present results on TCE adsorption and remediation on pure and hybrid CNT systems with a stress on the specific nature of substrate and molecular architecture that would contribute to competitive adsorption. The delineation of intermolecular interactions that contribute to efficient remediation is needed for custom, scalable field design of purification systems for a wide range of contaminants.

  10. Limiting factors for carbon based chemical double layer capacitors

    Science.gov (United States)

    Rose, M. Frank; Johnson, C.; Owens, T.; Stevens, B.

    1993-01-01

    The Chemical Double Layer (CDL) capacitor improves energy storage density dramatically when compared with conventional electrolytic capacitors. When compared to batteries, the CDL Capacitor is much less energy dense; however, the power density is orders of magnitude better. As a result, CDL-battery combinations present an interesting pulse power system with many potential applications. Due to the nature of the CDL it is inherently a low voltage device. The applications of the CDL can be tailored to auxiliary energy and burst mode storages which require fast charge/discharge cycles. Typical of the applications envisioned are power system backup, directed energy weapons concepts, electric automobiles, and electric actuators. In this paper, we will discuss some of the general characteristics of carbon-based CDL technology describing the structure, performance parameters, and methods of construction. Further, analytical and experimental results which define the state of the art are presented and described in terms of impact on applications.

  11. Recent advances in Carbon Nanotube based Enzymatic Fuel Cells

    Directory of Open Access Journals (Sweden)

    Serge eCosnier

    2014-10-01

    Full Text Available This review summarizes recent trends in the field of enzymatic fuel cells. Thanks to the high specificity of enzymes, biofuel cells can generate electrical energy by oxidation of a targeted fuel (sugars, alcohols or hydrogen at the anode and reduction of oxidants (O2, H2O2 at the cathode in complex media. The combination of carbon nanotubes, enzymes and redox mediators was widely exploited to develop biofuel cells since the electrons, involved in the bio-electrocatalytic processes, can be efficiently transferred from or to an external circuit. Original approaches to construct electron transfer based CNT-bioelectrodes and impressive biofuel cell performances are reported as well as biomedical applications.

  12. Nano-yarn carbon nanotube fiber based enzymatic glucose biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Zhigang; Burugapalli, Krishna; Moussy, Francis [Brunel Institute for Bioengineering, Brunel University, Uxbridge, Middlesex UB8 3PH (United Kingdom); Song, Wenhui [Wolfson Centre for Materials Processing, Mechanical Engineering, School of Engineering and Design, Brunel University, Uxbridge, Middlesex UB8 3PH (United Kingdom); Li Yali; Zhong Xiaohua, E-mail: wenhui.song@brunel.ac.uk [School of Materials Science and Engineering, Tianjin University, Weijin Road 92, Nankai District, Tianjin 300073 (China)

    2010-04-23

    A novel brush-like electrode based on carbon nanotube (CNT) nano-yarn fiber has been designed for electrochemical biosensor applications and its efficacy as an enzymatic glucose biosensor demonstrated. The CNT nano-yarn fiber was spun directly from a chemical-vapor-deposition (CVD) gas flow reaction using a mixture of ethanol and acetone as the carbon source and an iron nano-catalyst. The fiber, 28 {mu}m in diameter, was made of bundles of double walled CNTs (DWNTs) concentrically compacted into multiple layers forming a nano-porous network structure. Cyclic voltammetry study revealed a superior electrocatalytic activity for CNT fiber compared to the traditional Pt-Ir coil electrode. The electrode end tip of the CNT fiber was freeze-fractured to obtain a unique brush-like nano-structure resembling a scale-down electrical 'flex', where glucose oxidase (GOx) enzyme was immobilized using glutaraldehyde crosslinking in the presence of bovine serum albumin (BSA). An outer epoxy-polyurethane (EPU) layer was used as semi-permeable membrane. The sensor function was tested against a standard reference electrode. The sensitivities, linear detection range and linearity for detecting glucose for the miniature CNT fiber electrode were better than that reported for a Pt-Ir coil electrode. Thermal annealing of the CNT fiber at 250 deg. C for 30 min prior to fabrication of the sensor resulted in a 7.5 fold increase in glucose sensitivity. The as-spun CNT fiber based glucose biosensor was shown to be stable for up to 70 days. In addition, gold coating of the electrode connecting end of the CNT fiber resulted in extending the glucose detection limit to 25 {mu}M. To conclude, superior efficiency of CNT fiber for glucose biosensing was demonstrated compared to a traditional Pt-Ir sensor.

  13. Nano-yarn carbon nanotube fiber based enzymatic glucose biosensor.

    Science.gov (United States)

    Zhu, Zhigang; Song, Wenhui; Burugapalli, Krishna; Moussy, Francis; Li, Ya-Li; Zhong, Xiao-Hua

    2010-04-23

    A novel brush-like electrode based on carbon nanotube (CNT) nano-yarn fiber has been designed for electrochemical biosensor applications and its efficacy as an enzymatic glucose biosensor demonstrated. The CNT nano-yarn fiber was spun directly from a chemical-vapor-deposition (CVD) gas flow reaction using a mixture of ethanol and acetone as the carbon source and an iron nano-catalyst. The fiber, 28 microm in diameter, was made of bundles of double walled CNTs (DWNTs) concentrically compacted into multiple layers forming a nano-porous network structure. Cyclic voltammetry study revealed a superior electrocatalytic activity for CNT fiber compared to the traditional Pt-Ir coil electrode. The electrode end tip of the CNT fiber was freeze-fractured to obtain a unique brush-like nano-structure resembling a scale-down electrical 'flex', where glucose oxidase (GOx) enzyme was immobilized using glutaraldehyde crosslinking in the presence of bovine serum albumin (BSA). An outer epoxy-polyurethane (EPU) layer was used as semi-permeable membrane. The sensor function was tested against a standard reference electrode. The sensitivities, linear detection range and linearity for detecting glucose for the miniature CNT fiber electrode were better than that reported for a Pt-Ir coil electrode. Thermal annealing of the CNT fiber at 250 degrees C for 30 min prior to fabrication of the sensor resulted in a 7.5 fold increase in glucose sensitivity. The as-spun CNT fiber based glucose biosensor was shown to be stable for up to 70 days. In addition, gold coating of the electrode connecting end of the CNT fiber resulted in extending the glucose detection limit to 25 microM. To conclude, superior efficiency of CNT fiber for glucose biosensing was demonstrated compared to a traditional Pt-Ir sensor. PMID:20348597

  14. Ablation Properties of the Carbon-Based Composites Used in Artificial Heat Source Under Fire Accident

    Institute of Scientific and Technical Information of China (English)

    TANG; Xian; HUANG; Jin-ming; ZHOU; Shao-jian; LUO; Zhi-fu

    2012-01-01

    <正>The ablation properties of the carbon-based composites used in artificial heat source under fire accident were investigated by the arc heater. In this work, we tested the carbon-based composites referring to Fig. 1. Their linear/mass ablation ratio and ablation morphologies were studied. The results showed that the carbon-based composites used in artificial heat source behaved well

  15. Output-based rebating of carbon taxes in the neighbor’s backyard

    OpenAIRE

    Böhringer, Christoph; Bye, Brita; Fæhn, Taran; Rosendahl , Knut Einar

    2014-01-01

    We investigate how carbon taxes combined with output-based rebating (OBR) in an open economy perform in interaction with the carbon policies of a large neighboring trading partner. Analytical results suggest that whether the purpose of the OBR policy is to compensate firms for carbon tax burdens or to maximize welfare (accounting for global emission reductions), the second-best OBR rate should be positive in most cases. Further, it should fall with the introduction of carbon taxation in the n...

  16. Output-based rebating of carbon taxes in the neighbor's backyard. Competitiveness, leakage and welfare

    OpenAIRE

    Christoph Böhringer; Brita Bye; Taran Fæhn; Knut Einar Rosendahl

    2014-01-01

    We investigate how carbon taxes combined with output-based rebating (OBR) in an open economy perform in interaction with the carbon policies of a large neighboring trading partner. Analytical results suggest that whether the purpose of the OBR policy is to compensate firms for carbon tax burdens or to maximize welfare (accounting for global emission reductions), the second-best OBR rate should be positive in most cases. Further, it should fall with the introduction of carbon taxation in the n...

  17. Alternative industrial carbon emissions benchmark based on input-output analysis

    Science.gov (United States)

    Han, Mengyao; Ji, Xi

    2016-05-01

    Some problems exist in the current carbon emissions benchmark setting systems. The primary consideration for industrial carbon emissions standards highly relate to direct carbon emissions (power-related emissions) and only a portion of indirect emissions are considered in the current carbon emissions accounting processes. This practice is insufficient and may cause double counting to some extent due to mixed emission sources. To better integrate and quantify direct and indirect carbon emissions, an embodied industrial carbon emissions benchmark setting method is proposed to guide the establishment of carbon emissions benchmarks based on input-output analysis. This method attempts to link direct carbon emissions with inter-industrial economic exchanges and systematically quantifies carbon emissions embodied in total product delivery chains. The purpose of this study is to design a practical new set of embodied intensity-based benchmarks for both direct and indirect carbon emissions. Beijing, at the first level of carbon emissions trading pilot schemes in China, plays a significant role in the establishment of these schemes and is chosen as an example in this study. The newly proposed method tends to relate emissions directly to each responsibility in a practical way through the measurement of complex production and supply chains and reduce carbon emissions from their original sources. This method is expected to be developed under uncertain internal and external contexts and is further expected to be generalized to guide the establishment of industrial benchmarks for carbon emissions trading schemes in China and other countries.

  18. Space-based lidar measurements of global ocean carbon stocks

    Science.gov (United States)

    Behrenfeld, Michael J.; Hu, Yongxiang; Hostetler, Chris A.; Dall'Olmo, Giorgio; Rodier, Sharon D.; Hair, John W.; Trepte, Charles R.

    2013-08-01

    Global ocean phytoplankton biomass (Cphyto) and total particulate organic carbon (POC) stocks have largely been characterized from space using passive ocean color measurements. A space-based light detection and ranging (lidar) system can provide valuable complementary observations for Cphyto and POC assessments, with benefits including day-night sampling, observations through absorbing aerosols and thin cloud layers, and capabilities for vertical profiling through the water column. Here we use measurements from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) to quantify global Cphyto and POC from retrievals of subsurface particulate backscatter coefficients (bbp). CALIOP bbp data compare favorably with airborne, ship-based, and passive ocean data and yield global average mixed-layer standing stocks of 0.44 Pg C for Cphyto and 1.9 Pg for POC. CALIOP-based Cphyto and POC data exhibit global distributions and seasonal variations consistent with ocean plankton ecology. Our findings support the use of spaceborne lidar measurements for advancing understanding of global plankton systems.

  19. A Review of Carbon Nanotubes-Based Gas Sensors

    Directory of Open Access Journals (Sweden)

    Yun Wang

    2009-01-01

    Full Text Available Gas sensors have attracted intensive research interest due to the demand of sensitive, fast response, and stable sensors for industry, environmental monitoring, biomedicine, and so forth. The development of nanotechnology has created huge potential to build highly sensitive, low cost, portable sensors with low power consumption. The extremely high surface-to-volume ratio and hollow structure of nanomaterials is ideal for the adsorption of gas molecules. Particularly, the advent of carbon nanotubes (CNTs has fuelled the inventions of gas sensors that exploit CNTs' unique geometry, morphology, and material properties. Upon exposure to certain gases, the changes in CNTs' properties can be detected by various methods. Therefore, CNTs-based gas sensors and their mechanisms have been widely studied recently. In this paper, a broad but yet in-depth survey of current CNTs-based gas sensing technology is presented. Both experimental works and theoretical simulations are reviewed. The design, fabrication, and the sensing mechanisms of the CNTs-based gas sensors are discussed. The challenges and perspectives of the research are also addressed in this review.

  20. Multi-walled carbon nanotube-based RF antennas.

    Science.gov (United States)

    Elwi, Taha A; Al-Rizzo, Hussain M; Rucker, Daniel G; Dervishi, Enkeleda; Li, Zhongrui; Biris, Alexandru S

    2010-01-29

    A novel application that utilizes conductive patches composed of purified multi-walled carbon nanotubes (MWCNTs) embedded in a sodium cholate composite thin film to create microstrip antennas operating in the microwave frequency regime is proposed. The MWCNTs are suspended in an adhesive solvent to form a conductive ink that is printed on flexible polymer substrates. The DC conductivity of the printed patches was measured by the four probe technique and the complex relative permittivity was measured by an Agilent E5071B probe. The commercial software package, CST Microwave Studio (MWS), was used to simulate the proposed antennas based on the measured constitutive parameters. An excellent agreement of less than 0.2% difference in resonant frequency is shown. Simulated and measured results were also compared against identical microstrip antennas that utilize copper conducting patches. The proposed MWCNT-based antennas demonstrate a 5.6% to 2.2% increase in bandwidth, with respect to their corresponding copper-based prototypes, without significant degradation in gain and/or far-field radiation patterns.

  1. Robotic hand with locking mechanism using TCP muscles for applications in prosthetic hand and humanoids

    Science.gov (United States)

    Saharan, Lokesh; Tadesse, Yonas

    2016-04-01

    This paper presents a biomimetic, lightweight, 3D printed and customizable robotic hand with locking mechanism consisting of Twisted and Coiled Polymer (TCP) muscles based on nylon precursor fibers as artificial muscles. Previously, we have presented a small-sized biomimetic hand using nylon based artificial muscles and fishing line muscles as actuators. The current study focuses on an adult-sized prosthetic hand with improved design and a position/force locking system. Energy efficiency is always a matter of concern to make compact, lightweight, durable and cost effective devices. In natural human hand, if we keep holding objects for long time, we get tired because of continuous use of energy for keeping the fingers in certain positions. Similarly, in prosthetic hands we also need to provide energy continuously to artificial muscles to hold the object for a certain period of time, which is certainly not energy efficient. In this work we, describe the design of the robotic hand and locking mechanism along with the experimental results on the performance of the locking mechanism.

  2. Benefits of microprocessor-controlled prosthetic knees to limited community ambulators: systematic review.

    Science.gov (United States)

    Kannenberg, Andreas; Zacharias, Britta; Pröbsting, Eva

    2014-01-01

    The benefits of microprocessor-controlled prosthetic knees (MPKs) have been well established in community ambulators (Medicare Functional Classification Level [MFCL]-3) with a transfemoral amputation (TFA). A systematic review of the literature was performed to analyze whether limited community ambulators (MFCL-2) may also benefit from using an MPK in safety, performance-based function and mobility, and perceived function and satisfaction. We searched 10 scientific databases for clinical trials with MPKs and identified six publications with 57 subjects with TFA and MFCL-2 mobility grade. Using the criteria of a Cochrane Review on prosthetic components, we rated methodological quality moderate in four publications and low in two publications. MPK use may significantly reduce uncontrolled falls by up to 80% as well as significantly improve indicators of fall risk. Performance-based outcome measures suggest that persons with MFCL-2 mobility grade may be able to walk about 14% to 25% faster on level ground, be around 20% quicker on uneven surfaces, and descend a slope almost 30% faster when using an MPK. The results of this systematic review suggest that trial fittings may be used to determine whether or not individuals with TFA and MFCL-2 mobility grade benefit from MPK use. Criteria for patient selection and assessment of trial fitting success or failure are proposed.

  3. Benefits of microprocessor-controlled prosthetic knees to limited community ambulators: Systematic review

    Directory of Open Access Journals (Sweden)

    Andreas Kannenberg, MD, PhD

    2015-03-01

    Full Text Available The benefits of microprocessor-controlled prosthetic knees (MPKs have been well established in community ambulators (Medicare Functional Classification Level [MFCL]-3 with a transfemoral amputation (TFA. A systematic review of the literature was performed to analyze whether limited community ambulators (MFCL-2 may also benefit from using an MPK in safety, performance-based function and mobility, and perceived function and satisfaction. We searched 10 scientific databases for clinical trials with MPKs and identified six publications with 57 subjects with TFA and MFCL-2 mobility grade. Using the criteria of a Cochrane Review on prosthetic components, we rated methodological quality moderate in four publications and low in two publications. MPK use may significantly reduce uncontrolled falls by up to 80% as well as significantly improve indicators of fall risk. Performance-based outcome measures suggest that persons with MFCL-2 mobility grade may be able to walk about 14% to 25% faster on level ground, be around 20% quicker on uneven surfaces, and descend a slope almost 30% faster when using an MPK. The results of this systematic review suggest that trial fittings may be used to determine whether or not individuals with TFA and MFCL-2 mobility grade benefit from MPK use. Criteria for patient selection and assessment of trial fitting success or failure are proposed.

  4. An illusionary prosthetic design for a unilateral cleft palate patient

    Directory of Open Access Journals (Sweden)

    Andaç Barkın Bavbek

    2014-01-01

    Full Text Available The prosthetic rehabilitation is an important part of the cleft lip and palate therapy assisting orthodontic and orthognathic treatments. Prosthesis does not only help to improve function and aesthetics but also needs to facilitate a better oral health. The aim of this report is to introduce the prosthetic approach of a 21-year-old female unilateral cleft palate patient that considered reinforcing the mobile canine adjacent to the cleft, easing the elimination of dental plaque from the remaining fistula and reaching an accurate occlusion. Facial aesthetics was established by the illusionary effect of a removable crown complex which is joined onto a fixed partial denture with a precision attachment system.

  5. Customized mold radiotherapy with prosthetic apparatus for oral cancers

    International Nuclear Information System (INIS)

    Eight patients (6 males, 2 females; median age, 78 years; age range, 31-94 years) were treated by mold radiotherapy with a prosthetic apparatus for oral cancers between October 2006 and March 2013. The primary sites were the tongue in 3 cases, hard palate and buccal mucosa in 2 cases each, and oral floor in 1 case. The type of treatment consisted of radical radiotherapy and palliative radiotherapy in 2 cases each, and preoperative radiotherapy, postoperative radiotherapy, additional radiotherapy after external beam radiotherapy and systemic chemotherapy in 1 case each. Patients received 40-50 Gy in 8-10 fractions with mold radiotherapy. Two patients who received radical radiotherapy showed no signs of recurrence or metastasis. The present therapy contributed to patients' palliative, postoperative, and preoperative therapy. Mold radiotherapy with a prosthetic appliance was performed safely and was a useful treatment for several types of oral cancer. (author)

  6. Contemporary management of prosthetic valve endocarditis: principals and future outlook.

    Science.gov (United States)

    O'Connor, Cormac T; Kiernan, Thomas J

    2015-05-01

    Infective endocarditis involving prosthetic valves accounts for 20% of all endocarditis cases. Rising in prevalence due to increasing placement of valvular prostheses, prosthetic valve endocarditis (PVE) is more difficult to diagnose by conventional methods, associated with more invasive infection and increased mortality. This report explores the existing literature in identifying a direct approach to the management of PVE; such as adjuncts to establishing a diagnosis (for instance positron emission tomography/computed tomography and radiolabeled leukocyte scintigraphy), the trends in specific pathogens associated with PVE and the recommended antimicrobials for each. The patterns of disease requiring surgical intervention are also highlighted and explored. In addition, a 5-year outlook offers consolidated knowledge on epidemiological trends of both culprit organisms and population subgroups suffering (and projected to suffer) from PVE. PMID:25865118

  7. Asymmetric electrochemical supercapacitor, based on polypyrrole coated carbon nanotube electrodes

    International Nuclear Information System (INIS)

    Highlights: • Polypyrrole (PPy) coated multiwalled carbon nanotubes (MWCNT) were prepared. • New method is based on the use of new electrochemically active dopants for PPy. • The dopans provided dispersion of MWCNT and promoted PPy coating formation. • Symmetric PPy–MWCNT supercapacitors showed high capacitance and low resistance. • Asymmetric PPy–MWCNT/VN–MWCNT devices and modules allowed larger voltage window. - Abstract: Conductive polypyrrole (PPy) polymer – multiwalled carbon nanotubes (MWCNT) composites were synthesized using sulfanilic acid azochromotrop (SPADNS) and sulfonazo III sodium salt (CHR-BS) as anionic dopants for chemical polymerization of PPy. The composites were tested for application in electrodes of electrochemical supercapacitors (ES). Sedimentation tests, electrophoretic deposition experiments and Fourier transform infrared spectroscopy (FTIR) investigations showed that strong adsorption of anionic CHR-BS on MWCNT provided MWCNT dispersion. The analysis of scanning and transmission electron microscopy data demonstrated that the use of CHR-BS allowed the formation of PPy coatings on MWCNT. As a result, the composites, prepared using CHR-BS, showed higher capacitance, compared to the composites, prepared using SPADNS. The electrodes, containing MWCNT, coated with PPy showed a capacitance of 179 F g−1 for active mass loading of 10 mg cm−2, good capacitance retention at scan rates in the range of 2–100 mV s−1 and excellent cyclic stability. Asymmetric ES devices, containing positive PPy–MWCNT electrodes and negative vanadium nitride (VN)–MWCNT electrodes showed significant improvement in energy storage performance, compared to the symmetric ES due to the larger voltage window. The low impedance and high capacitance of the individual cells paved the way to the development of modules with higher voltage, which showed good electrochemical performance

  8. Rapid Molecular Microbiologic Diagnosis of Prosthetic Joint Infection

    OpenAIRE

    Cazanave, Charles; Kerryl E. Greenwood-Quaintance; Hanssen, Arlen D.; Karau, Melissa J.; Schmidt, Suzannah M.; Gomez Urena, Eric O.; Mandrekar, Jayawant N.; OSMON, DOUGLAS R.; Lough, Lindsay E.; Pritt, Bobbi S.; Steckelberg, James M.; Patel, Robin

    2013-01-01

    We previously showed that culture of samples obtained by prosthesis vortexing and sonication was more sensitive than tissue culture for prosthetic joint infection (PJI) diagnosis. Despite improved sensitivity, culture-negative cases remained; furthermore, culture has a long turnaround time. We designed a genus-/group-specific rapid PCR assay panel targeting PJI bacteria and applied it to samples obtained by vortexing and sonicating explanted hip and knee prostheses, and we compared the result...

  9. Lactococcus garvieae Endocarditis on a Prosthetic Biological Aortic Valve.

    Science.gov (United States)

    Tsur, A; Slutzki, T; Flusser, D

    2015-09-01

    Lactococcus garvieae (LG) endocarditis is a rare disease in humans. There are only about 16 reported cases in the world. We report a 76-year-old male patient with LG endocarditis. In depth interview with the patient revealed that 2 weeks prior to admission, he had eaten sushi containing raw fish. Unlike many of the other infections reported, which were on a native mitral valve, our patient's vegetation was on a prosthetic aortic valve.

  10. Increasing risk of prosthetic joint infection after total hip arthroplasty

    DEFF Research Database (Denmark)

    Dale, Håvard; Fenstad, Anne M; Hallan, Geir;

    2012-01-01

    Background and purpose The risk of revision due to infection after primary total hip arthroplasty (THA) has been reported to be increasing in Norway. We investigated whether this increase is a common feature in the Nordic countries (Denmark, Finland, Norway, and Sweden). Materials and methods The...... explain this increase. We believe that there has been an actual increase in the incidence of prosthetic joint infections after THA....

  11. The Role of Prosthetic Dentistry in Mass Disaster Identification

    OpenAIRE

    Vermylen, Y.

    2002-01-01

    Dentistry plays a very important role in the identification of the victims in mass disasters. More than 50% of the identification work is concluded by dental means and investigation. Prosthetic work, and especially full rehabilitations with dental implants, crowns and bridges, is very valuable for dental identification. The biggest problems, however, are full upper and lower dentures. Marking of dentures would be a very valuable aid in identification procedures and very easy to do at a law...

  12. Peri-Prosthetic Infection in the Orthopedic Tumor Patient

    OpenAIRE

    Daniel Allison MD, MBA, FACS; Eddie Huang, MD; Elke Ahlmann, MD; Scott Carney, MD; Ling Wang, PA-C; Lawrence Menendez, MD, FACS

    2014-01-01

    Background: Infection complicates traditional joint reconstruction prostheses in up to 7% of cases, with even higher rates in oncologic cases.  Questions / Purposes: The authors ask if prosthetic infection in bone tumor patients is associated with any epidemiologic, treatment, or outcome variables that could influence management of these difficult conditions.  Patients and Methods: Authors retrospectively reviewed 329 consecutive bone tumor (malignant and benign) patients treated with h...

  13. PATIENT SATISFACTION WITH ORTHOPEDIC AND PROSTHETIC MEDICAL DEVICES

    Directory of Open Access Journals (Sweden)

    Ivona Malovecká

    2015-09-01

    Full Text Available Collecting information about patient satisfaction with orthopedic and prosthetic medical devices in terms of utility, tolerance, and compliance is essential for verifying and improving the quality of these devices. In addition, such information is useful for improving the patients’ quality of life, and the quality management systems of health care providers. This study assessed patient satisfaction with these devices from a sample of patients with orthopedic, neurologic, and rheumatic diseases at the Specialized Hospital for Orthopedic Prosthetics and at the premises of the Dispenser of Orthopedic and Prosthetic Medical Devices, both in Bratislava in the Slovak Republic. The assessment involved a translated and validated questionnaire about patient satisfaction with orthopedic and prosthetic medical devices to evaluate key factors of weight, fit, appearance, comfort, pain free, free of abrasiveness, ease of application, and durability of each device. The study samples consisted of patients with lower limb problems (42.5%, spine problems (26.9%, and a combination of leg and spine issues (25.9%. Orthopedic disease occurred in 73.6% of these patients, a combination of orthopedic and neurologic disease in 13.5%, and neurologic disease in 7.3%. Orthopedic insoles (36.3%, hip belts (17.6%, and the corset on the spine (5.2% were the most used devices. Overall, the medical devices rated highly, with a high proportion of patients voting “strongly satisfied” in five of the eight key factors (range 51.8 to 63.2%, followed by a moderately lower proportion for durability (43.5%, comfort (37.3%, and appearance (31.1%. The comfort in wearing the device received the greatest patient dissatisfaction (22.8% of patients, followed by appearance (12.4%, and then fit (7.3%.

  14. Fungal prosthetic joint infection after total knee arthroplasty

    OpenAIRE

    Reddy, Kankanala J; Shah, Jay D; Rohit V Kale; T Jayakrishna Reddy

    2013-01-01

    Fungal prosthetic joint infection after total knee arthroplasty (TKA) is a rare complication. Lacunae exist in the management of this complication. 62 year old lady presented with pain and swelling in left knee and was diagnosed as Candida tropicalis fungal infection after TKA. She underwent debridement, resection arthroplasty and antifungal plus antibiotic loaded cement spacer insertion, antifungal therapy with fluconazole followed by delayed revision TKA and further fluconazole therapy. Tot...

  15. Lactococcus garvieae Endocarditis on a Prosthetic Biological Aortic Valve.

    Science.gov (United States)

    Tsur, A; Slutzki, T; Flusser, D

    2015-09-01

    Lactococcus garvieae (LG) endocarditis is a rare disease in humans. There are only about 16 reported cases in the world. We report a 76-year-old male patient with LG endocarditis. In depth interview with the patient revealed that 2 weeks prior to admission, he had eaten sushi containing raw fish. Unlike many of the other infections reported, which were on a native mitral valve, our patient's vegetation was on a prosthetic aortic valve. PMID:25295408

  16. Indium-111 leukocyte localization in infected prosthetic graft

    Energy Technology Data Exchange (ETDEWEB)

    Purnell, G.L.; Walker, C.W.; Allison, J.W.; Dalrymple, G.V. (Univ. of Arkansas for Medical Sciences, Little Rock (USA))

    1990-08-01

    Infective endocarditis can be difficult to prove, even in the face of strong clinical suspicion. A case in which standard methods of diagnosis failed to demonstrate endocarditis in a patient with recurrent Staphylococcus aureus bacteremia and porcine aortic valve is reported. An In-111 labelled leukocyte SPECT study demonstrated uptake in the aortic root and leaflets, and autopsy demonstrated vegetations on the leaflets. In-111 may prove useful in demonstrating endocarditis in patients with prosthetic valve infection.

  17. [[Medico-historical findings of (neuro-) prosthetics: an online survey].

    Science.gov (United States)

    Ohnemus, Dirk; Otte, Andreas

    2014-01-01

    This article presents an online survey on medico-historical (neuro-)prostheses. Important findings of the past 3000 years are outlined: toe prostheses from ancient Egypt, the Capua leg prosthesis, Götz von Berlichingen's artificial hands and Sauerbruch's prosthetic arm. These historical examples are compared with modern neuroprosthetics. It is also shown that historical prostheses were in no way primitive and, even more, that ancient people already used first intelligent medical engineering approaches. PMID:26548022

  18. Temporospatial changes of carbon footprint based on energy consumption in China

    Institute of Scientific and Technical Information of China (English)

    CHUAI Xiaowei; LAI Li; HUANG Xianjin; ZHAO Rongqin; WANG Wanjing; CHEN Zhigang

    2012-01-01

    Study on regional carbon emission is one of the hot topics under the background of global climate change and low-carbon economic development,and also help to establish different low-carbon strategies for different regions.On the basis of energy consumption and land use data of different regions in China from 1999 to 2008,this paper established carbon emission and carbon footprint models based on total energy consumption,and calculated the amount of carbon emissions and carbon footprint in different regions of China from 1999 to 2008.The author also analyzed carbon emission density and per unit area carbon footprint for each region.Finally,advices for decreasing carbon footprint were put forward.The main conclusions are as follows:(1) Carbon emissions from total energy consumption increased 129% from 1999 to 2008 in China,but its spatial distribution pattern among different regions just slightly changed,the sorting of carbon emission amount was:Eastern China > Northern China > Central and Southern China > Southwest China > Northwest China.(2) The sorting of carbon emission density was:Eastern China > Northeast China > Central and Southern China > Northern China > Southwest China > Northwest China from 1999 to 2003,but from 2004 Central and Southern China began to have higher carbon emission density than Northeast China,the order of other regions did not change.(3) Carbon footprint increased significantly since the rapid increasing of carbon emissions and less increasing area of productive land in different regions of China from 1999 to 2008.Northern China had the largest carbon footprint,and Northwest China,Eastern China,Northern China,Central and Southern China followed in turn,while Southwest China presented the lowest area of carbon footprint and the highest percentage of carbon absorption.(4) Mainly influenced by regional land area,Northern China presented the highest per unit area carbon footprint and followed by Eastern China,and Northeast

  19. Single-Walled Carbon-Nanotubes-Based Organic Memory Structures.

    Science.gov (United States)

    Fakher, Sundes; Nejm, Razan; Ayesh, Ahmad; Al-Ghaferi, Amal; Zeze, Dagou; Mabrook, Mohammed

    2016-01-01

    The electrical behaviour of organic memory structures, based on single-walled carbon-nanotubes (SWCNTs), metal-insulator-semiconductor (MIS) and thin film transistor (TFT) structures, using poly(methyl methacrylate) (PMMA) as the gate dielectric, are reported. The drain and source electrodes were fabricated by evaporating 50 nm gold, and the gate electrode was made from 50 nm-evaporated aluminium on a clean glass substrate. Thin films of SWCNTs, embedded within the insulating layer, were used as the floating gate. SWCNTs-based memory devices exhibited clear hysteresis in their electrical characteristics (capacitance-voltage (C-V) for MIS structures, as well as output and transfer characteristics for transistors). Both structures were shown to produce reliable and large memory windows by virtue of high capacity and reduced charge leakage. The hysteresis in the output and transfer characteristics, the shifts in the threshold voltage of the transfer characteristics, and the flat-band voltage shift in the MIS structures were attributed to the charging and discharging of the SWCNTs floating gate. Under an appropriate gate bias (1 s pulses), the floating gate is charged and discharged, resulting in significant threshold voltage shifts. Pulses as low as 1 V resulted in clear write and erase states. PMID:27598112

  20. Carbon nanotube-based supercapacitors using low cost collectors

    Science.gov (United States)

    Amirhoseiny, Maryam; Zandi, Majid; Mosayyebi, Abolghasem; Khademian, Mehrzad

    2016-01-01

    In this work, electrochemical double layer supercapacitors were fabricated using multiwalled carbon nanotube (MWCNT) composite microfilm as electrode. To improve the electrochemical properties, MWCNTs were functionalized with -COOH by acid treatments. CNT/PVA films have been deposited on different current collectors by spin coating to drastically enhance the electrode performance. Electrode fabrication involved various stages preparing of the CNT composite, and coating of the CNT/PVA paste on different substrates which also served as current collector. Al, Ni and graphite were used and compared as current collectors. The surface morphology of the fabricated electrodes was investigated with scanning electrode microscopy (SEM). Overall cell performance was evaluated with a multi-channel potentiostat/galvanostat analyzer. Each supercapacitor cell was subjected to charge-discharge cycling study at different current rates from 0.2Ag-1 to 1Ag-1. The results showed that graphite-based electrodes offer advantages of significantly higher conductivity and superior capacitive behavior compared to thin film electrodes formed on Ni and Al current collectors. The specific capacitance of graphite based electrode is found to be 29Fg-1.

  1. Single-Walled Carbon-Nanotubes-Based Organic Memory Structures

    Directory of Open Access Journals (Sweden)

    Sundes Fakher

    2016-09-01

    Full Text Available The electrical behaviour of organic memory structures, based on single-walled carbon-nanotubes (SWCNTs, metal–insulator–semiconductor (MIS and thin film transistor (TFT structures, using poly(methyl methacrylate (PMMA as the gate dielectric, are reported. The drain and source electrodes were fabricated by evaporating 50 nm gold, and the gate electrode was made from 50 nm-evaporated aluminium on a clean glass substrate. Thin films of SWCNTs, embedded within the insulating layer, were used as the floating gate. SWCNTs-based memory devices exhibited clear hysteresis in their electrical characteristics (capacitance–voltage (C–V for MIS structures, as well as output and transfer characteristics for transistors. Both structures were shown to produce reliable and large memory windows by virtue of high capacity and reduced charge leakage. The hysteresis in the output and transfer characteristics, the shifts in the threshold voltage of the transfer characteristics, and the flat-band voltage shift in the MIS structures were attributed to the charging and discharging of the SWCNTs floating gate. Under an appropriate gate bias (1 s pulses, the floating gate is charged and discharged, resulting in significant threshold voltage shifts. Pulses as low as 1 V resulted in clear write and erase states.

  2. Piezoresistivity in Carbon Fiber Reinforced Cement Based Composites

    Institute of Scientific and Technical Information of China (English)

    Bing CHEN; Keru WU; Wu YAO

    2004-01-01

    The resu lts of some i nteresti ng investigation on the piezoresistivity of ca rbon fi ber reinforced cement based com posites (CFRC) are presented with the prospect of developing a new nondestructive testing method to assess the integrity of the composite. The addition of short carbon fibers to cement-based mortar or concrete improves the structural performance and at the same time significantly decreases the bulk electrical resistivity. This makes CFRC responsive to the smart behavior by measuring the resistance change with uniaxial pressure. The piezoresistivity of CFRC under different stress was studied, at the same time the damage occurring inner specimens was detected by acoustic emission as well. Test results show that there exists a marking pressure dependence of the conductivity in CFRC, in which the so-called negative pressure coefficient of resistive (NPCR) and positive pressure coefficient of resistive (PPCR) are observed under low and high pressure. Under constant pressures, time-dependent resistivity is an outstanding characteristic for the composites, which is defined as resistance creep. The breakdown and rebuild-up process of conductive network under pressure may be responsible for the pressure dependence of resistivity.

  3. Nanodevices based on Membrane-Carbon Nanotube Hybrid Structures

    Science.gov (United States)

    Jin, Hye Jun; Kim, Tae Hyun; Namgung, Seon; Hong, Seunghun; Lee, Sang Hun; Park, Tai Hyun

    2010-03-01

    Proteins in cell membrane have been drawing attention due to their versatile functionalities such as ion transfer for neuronal activity and selective binding for sensory systems. However, it is still very difficult to manipulate and study those proteins because they easily lose their functionalities without lipid membranes. We developed a method to coat lipid membranes containing various functional membrane proteins on single-walled carbon nanotube (swCNT)-based field effect transistors (FETs). In this hybrid structure, the activity of membrane proteins can be monitored by underlying swCNT-FETs, allowing us to easily study the functionalities of membrane proteins. Furthermore, we built advanced devices based on these hybrid structures. For an example, we coated lipid membrane containing `olfactory receptors' on swCNT-FETs, resulting in `bioelectric nose' systems. The bioelectric nose system had high sensitivity and human nose-like selectivity to odorant molecules. This talk will also discuss about the future prospect of these membrane-CNT hybrid structures.

  4. Processing of Prosthetic Heart Valve Sounds from Anechoic Tank Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J V; Meyer, A W

    2001-03-20

    People with serious cardiac problems have had their life span extended with the development of the prosthetic heart valve. However, the valves operate continuously at approximately 39 million cycles per year and are therefore subject to structural failures either by faulty design or material fatigue. The development of a non-invasive technique using an acoustic contact microphone and sophisticated signal processing techniques has been proposed and demonstrated on limited data sets. In this paper we discuss an extension of the techniques to perform the heart valve tests in an anechoic like. Here the objective is to extract a ''pure'' sound or equivalently the acoustical vibration response of the prosthetic valves in a quiet environment. The goal is to demonstrate that there clearly exist differences between values which have a specific mechanical defect known as single leg separation (SLS) and non-defective valves known as intact (INT). We discuss the signal processing and results of anechoic acoustic measurements on 50 prosthetic valves in the tank. Finally, we show the results of the individual runs for each valve, point out any of the meaningful features that could be used to distinguish the SLS from INT and summarize the experiments.

  5. NIRS monitoring of muscle contraction to control a prosthetic device

    Science.gov (United States)

    Bianchi, Thomas; Zambarbieri, Daniela; Beltrami, Giorgio; Verni, Gennaro

    1999-01-01

    The fitting of upper-extremity amputees requires special efforts, and its significance has been increased by the development of the myoelectrically controlled prosthetic arm. This solution is not free of problems due to the nature of the amputation, to the electromagnetic noise affecting the myelectrical signal and to the perspiration due to the contact between socket and the residual limb. Starting from the fact that NIRS and electromyographic signals are similar during a muscle contraction, we have first studied the NIRS signal during forearm muscle contractions in normal and amputee subjects. Then a new system to interface the NIRS unit and the myoelectrical prosthetic hand has been developed. The NIRS unit has been used as optical sensor and all the operations (I/O and signal processing) are performed via software. This system has been tested on normal and amputee subjects performing hand grasping using a visual biofeedback control scheme. All the subjects have been able to perform these operations demonstrating the NIRS technique. This could represent an alternative solution for controlling a prosthetic device.

  6. Evaluation of new suspension system for limb prosthetics

    Science.gov (United States)

    2014-01-01

    Background Good prosthetic suspension system secures the residual limb inside the prosthetic socket and enables easy donning and doffing. This study aimed to introduce, evaluate and compare a newly designed prosthetic suspension system (HOLO) with the current suspension systems (suction, pin/lock and magnetic systems). Methods All the suspension systems were tested (tensile testing machine) in terms of the degree of the shear strength and the patient’s comfort. Nine transtibial amputees participated in this study. The patients were asked to use four different suspension systems. Afterwards, each participant completed a questionnaire for each system to evaluate their comfort. Furthermore, the systems were compared in terms of the cost. Results The maximum tensile load that the new system could bear was 490 N (SD, 5.5) before the system failed. Pin/lock, magnetic and suction suspension systems could tolerate loads of580 N (SD, 8.5), 350.9 (SD, 7) and 310 N (SD, 8.4), respectively. Our subjects were satisfied with the new hook and loop system, particularly in terms of easy donning and doffing. Furthermore, the new system is considerably cheaper (35 times) than the current locking systems in the market. Conclusions The new suspension system could successfully retain the prosthesis on the residual limb as a good alternative for lower limb amputees. In addition, the new system addresses some problems of the existing systems and is more cost effective than its counterparts. PMID:24410918

  7. Iodine-125 orbital brachytherapy with a prosthetic implant in situ

    Energy Technology Data Exchange (ETDEWEB)

    Stannard, Clare [Groote Schuur Hospital and Cape Town Univ. (South Africa). Dept. of Radiation Oncology; Maree, Gert; Munro, Roger [Groote Schuur Hospital and Cape Town Univ. (South Africa). Dept. of Medical Physics; Lecuona, Karin [Groote Schuur Hospital and Cape Town Univ. (South Africa). Dept. of Ophthalmology; Sauerwein, Wolfgang [Universitaetsklinikum Essen (Germany). Strahlenklinik, NCTeam

    2011-05-15

    Purpose: Brachytherapy is one method of irradiating the orbit after enucleation of an eye with a malignant tumor that has a potential to recur. It consists of 6 trains of I-125 seeds placed around the periphery of the orbit, a shorter central train, and a metal disc, loaded with seeds, placed beneath the eyelids. The presence of a prosthetic orbital implant requires omission of the central train and adjustment of the activity of the seeds in the anterior orbit around the prosthesis. Patients and Methods: This is a retrospective review of the technical modifications and outcome of 12 patients treated in this manner: 6 with retinoblastoma, 5 with malignant melanoma, and 1 with an intraocular rhabdomyosarcoma. The median dose was 35.5 Gy in 73 hours for retinoblastoma and 56 Gy in 141 hours for malignant melanoma. Patients with retinoblastoma and rhabdomyosarcoma also received chemotherapy. Results: The tubes can be placed satisfactorily around the prosthesis. The increased activity in the anterior half of the tubes produced comparable dose distributions. There have been no orbital recurrences, no extrusion of the prosthesis, and cosmesis is good. Conclusion: Insertion of a prosthetic implant at the time of enucleation greatly enhances the subsequent cosmetic appearance. This should be encouraged unless there is frank tumor in the orbit. Orbital brachytherapy without the central train continues to give excellent local control. The short treatment time and good cosmesis are added advantages. The patient is spared the expense and inconvenience of removing and replacing the prosthetic implant. (orig.)

  8. Prosthetic Leg Control in the Nullspace of Human Interaction

    Science.gov (United States)

    Gregg, Robert D.; Martin, Anne E.

    2016-01-01

    Recent work has extended the control method of virtual constraints, originally developed for autonomous walking robots, to powered prosthetic legs for lower-limb amputees. Virtual constraints define desired joint patterns as functions of a mechanical phasing variable, which are typically enforced by torque control laws that linearize the output dynamics associated with the virtual constraints. However, the output dynamics of a powered prosthetic leg generally depend on the human interaction forces, which must be measured and canceled by the feedback linearizing control law. This feedback requires expensive multi-axis load cells, and actively canceling the interaction forces may minimize the human's influence over the prosthesis. To address these limitations, this paper proposes a method for projecting virtual constraints into the nullspace of the human interaction terms in the output dynamics. The projected virtual constraints naturally render the output dynamics invariant with respect to the human interaction forces, which instead enter into the internal dynamics of the partially linearized prosthetic system. This method is illustrated with simulations of a transfemoral amputee model walking with a powered knee-ankle prosthesis that is controlled via virtual constraints with and without the proposed projection. PMID:27746585

  9. Enhancing the capacitances of electric double layer capacitors based on carbon nanotube electrodes by carbon dioxide activation and acid oxidization

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Polarizable electrodes of electric double layer capacitors(EDLCs) were made from carbon nanotubes(CNTs).Effect of carbon dioxide activation together with acid oxidation for the electrodes on the characteristics and performances of electrodes and EDLCs was studied.Carbon dioxide activation changed the microstructure of the electrodes,increased the effective surface area of CNTs and optimized the distribution of apertures of the electrodes.Acid oxidization modified the surface characteristics of CNTs.Based on the polarizable electrodes treated by carbon dioxide activation and acid oxidization,the performances of EDLCs were greatly enhanced.The specific capacitance of the electrodes with organic electrolyte was increased from 21.8 F/g to 60.4 F/g.

  10. Closing the carbon cycle through rational use of carbon-based fuels.

    Science.gov (United States)

    MacElroy, J M Don

    2016-01-01

    In this paper, a brief overview is presented of natural gas as a fuel resource with subsequent carbon capture and re-use as a means to facilitate reduction and eventual elimination of man-made carbon emissions. A particular focus is shale gas and, to a lesser extent, methane hydrates, with the former believed to provide the most reasonable alternative as a transitional fuel toward a low-carbon future. An emphasis is placed on the gradual elimination of fossil resource usage as a fuel over the coming 35 to 85 years and its eventual replacement with renewable resources and nuclear power. Furthermore, it is proposed that synthesis of chemical feedstocks from recycled carbon dioxide and hydrogen-rich materials should be undertaken for specific applications in the transport sector which require access to high energy density fuels. To achieve the latter, carbon dioxide capture is imperative and possible synthetic routes for chemical feedstock production are briefly reviewed.

  11. Closing the carbon cycle through rational use of carbon-based fuels.

    Science.gov (United States)

    MacElroy, J M Don

    2016-01-01

    In this paper, a brief overview is presented of natural gas as a fuel resource with subsequent carbon capture and re-use as a means to facilitate reduction and eventual elimination of man-made carbon emissions. A particular focus is shale gas and, to a lesser extent, methane hydrates, with the former believed to provide the most reasonable alternative as a transitional fuel toward a low-carbon future. An emphasis is placed on the gradual elimination of fossil resource usage as a fuel over the coming 35 to 85 years and its eventual replacement with renewable resources and nuclear power. Furthermore, it is proposed that synthesis of chemical feedstocks from recycled carbon dioxide and hydrogen-rich materials should be undertaken for specific applications in the transport sector which require access to high energy density fuels. To achieve the latter, carbon dioxide capture is imperative and possible synthetic routes for chemical feedstock production are briefly reviewed. PMID:26667055

  12. Perspective of Chinese Forest Carbon Absorption Trade Based on Low-Carbon Economy

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The paper analyzes the basis of forest carbon trade including the feasibility of carbon absorption trade,main body,platform and standard.The purposes of capital of carbon absorption trade is introduced.Caron absorption trade capital can be used to resettle ecological migrants,absorb employment,build forest and increase fund,increase local income,enhance forest science and technology development and launch environmental proportion.The perspective of developing forest carbon absorption trade is pointed out and the practical problems of developing forest carbon trade need to be solved.For example,the property problem of forest resources,value calculation problem of forest resources and sustainable development of forest.

  13. Carbon Cryogel and Carbon Paper-Based Silicon Composite Anode Materials for Lithium-Ion Batteries

    Science.gov (United States)

    Woodworth, James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. 6 One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nano-foams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. 1-5 Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  14. Silicon Composite Anode Materials for Lithium Ion Batteries Based on Carbon Cryogels and Carbon Paper

    Science.gov (United States)

    Woodworth, James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nanofoams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  15. Highly Efficient Procedure for the Synthesis of Fructone Fragrance Using a Novel Carbon based Acid

    Directory of Open Access Journals (Sweden)

    Xuezheng Liang

    2010-08-01

    Full Text Available The novel carbon based acid has been synthesized via one-step hydrothermal carbonization of furaldehyde and hydroxyethylsulfonic acid. A highly efficient procedure for the synthesis of fructone has been developed using the novel carbon based acid. The results showed that the catalyst possessed high activity for the reaction, giving a yield of over 95%. The advantages of high activity, stability, reusability and low cost for a simple synthesis procedure and wide applicability to various diols and β-keto esters make this novel carbon based acid one of the best choices for the reaction.

  16. Carbon nanotube macrofilm-based nanocomposite electrodes for energy applications

    Science.gov (United States)

    Cao, Zeyuan

    Finding new electrode materials for energy conversion and storage devices have been the focus of recent research in the fields of science and engineering. Suffering from poor electronic conductivity, chemical and mechanical stability, active electrode materials are usually coupled with different carbon nanostructured materials to form nanocomposite electrodes, showing promising electrochemical performance. Among the carbon nanostructured materials, carbon nanotube (CNT) macrofilms draw great attention owing to their extraordinary properties, such as a large specific surface area, exceptionally high conductivity, porous structure, flexibility, mechanical robustness, and adhesion. They could effectively enhance the electrochemical performance of the incorporated active materials in the nanocomposites. In this dissertation, CNT macrofilm-based nanocomposites are investigated for rechargeable lithium-ion batteries, supercapacitors, and electrocatalysts of fuel cells. The progressive research developed various nanocomposites from cathode materials to anode materials followed by a general nanocomposite solution due to the unique adhesive property of the fragmented CNT macrofilms. The in-situ synthesis strategy are explored to in-situ deposit unlithiated cathode materials V2O5 and lithiated cathode materials LiMn2O4 nanocrystals in the matrix of the CNT macrofilms as nanocomposites to be paired with metallic lithium in half cells. The presence of oxygen-containing functional groups on the surface of the CNT macrofilms after purification can enhance the association with the active materials to enable the facilitated transport of solvated ions to the electrolyte/electrode interfaces and increase the diffusion kinetics, consequently enhancing the battery performance in terms of high specific capacity, rate capability, and cycling stability. It is also significant to demonstrate a reliable, low-cost, and effective route to synthesize the family of metal oxides (MxOy (M=Fe, Co

  17. Carbon nanotube macrofilm-based nanocomposite electrodes for energy applications

    Science.gov (United States)

    Cao, Zeyuan

    Finding new electrode materials for energy conversion and storage devices have been the focus of recent research in the fields of science and engineering. Suffering from poor electronic conductivity, chemical and mechanical stability, active electrode materials are usually coupled with different carbon nanostructured materials to form nanocomposite electrodes, showing promising electrochemical performance. Among the carbon nanostructured materials, carbon nanotube (CNT) macrofilms draw great attention owing to their extraordinary properties, such as a large specific surface area, exceptionally high conductivity, porous structure, flexibility, mechanical robustness, and adhesion. They could effectively enhance the electrochemical performance of the incorporated active materials in the nanocomposites. In this dissertation, CNT macrofilm-based nanocomposites are investigated for rechargeable lithium-ion batteries, supercapacitors, and electrocatalysts of fuel cells. The progressive research developed various nanocomposites from cathode materials to anode materials followed by a general nanocomposite solution due to the unique adhesive property of the fragmented CNT macrofilms. The in-situ synthesis strategy are explored to in-situ deposit unlithiated cathode materials V2O5 and lithiated cathode materials LiMn2O4 nanocrystals in the matrix of the CNT macrofilms as nanocomposites to be paired with metallic lithium in half cells. The presence of oxygen-containing functional groups on the surface of the CNT macrofilms after purification can enhance the association with the active materials to enable the facilitated transport of solvated ions to the electrolyte/electrode interfaces and increase the diffusion kinetics, consequently enhancing the battery performance in terms of high specific capacity, rate capability, and cycling stability. It is also significant to demonstrate a reliable, low-cost, and effective route to synthesize the family of metal oxides (MxOy (M=Fe, Co

  18. Highly Efficient Procedure for the Synthesis of Fructone Fragrance Using a Novel Carbon based Acid

    OpenAIRE

    Xuezheng Liang; Shao-Qin Lv; Lin-Mei Rong; Sheng-Xian Zhao; Chunqing Li; Baowei Hu; Chenze Qi

    2010-01-01

    The novel carbon based acid has been synthesized via one-step hydrothermal carbonization of furaldehyde and hydroxyethylsulfonic acid. A highly efficient procedure for the synthesis of fructone has been developed using the novel carbon based acid. The results showed that the catalyst possessed high activity for the reaction, giving a yield of over 95%. The advantages of high activity, stability, reusability and low cost for a simple synthesis procedure and wide applicability to various diols ...

  19. STUDENTS' SELF-ASSESSMENT IN PRE-CLINICAL AND CLINICAL EDUCATION OF PROSTHETIC DENTISTRY

    Directory of Open Access Journals (Sweden)

    Dimiter Kirov

    2014-09-01

    Full Text Available Background: The ability to self-assess is a critical skill that all health professionals must be able to do, in order to achieve competence. This is essential for the doctors of dental medicine. During their education and practice they apply different clinical and para-clinical procedures. The aim is to evaluate the students' self-assessment skills during the education of clinic and pre-clinic of prosthetic dentistry. Material and methods: After the completion of certain work - preparation for full veneer crown, a questionnaire was provided to each student in preclinical course (n=30 and clinical course (n=30 for self-evaluation. The questionnaire involved: axial reduction, occlusal reduction, facial and lingual reduction, smoothing and finishing. The answers were based on the standard for the university grading scale. Than, the same questionnaire was fulfilled by the assistant professor without seeing students' self-evaluation. Results and Discussion: Results have been reported in percentages. 100% respond rate has been achieved. The students from the preclinical course tend to overestimate their performance (50%. The students from the clinical course tend to submit overall lower grades than the faculty evaluation (25%. Conclusions: The students from clinics have better self-assessment skills. The discrepancy was most pronounced in the junior students. The different evaluations (self-assessment and assistant professor's help students to improve their understanding of certain principles and improve the teaching effectiveness of education of prosthetic dentistry.

  20. Design, Sensing and Control of a Robotic Prosthetic Eye for Natural Eye Movement

    Directory of Open Access Journals (Sweden)

    J. J. Gu

    2006-01-01

    Full Text Available Loss of an eye is a tragedy for a person, who may suffer psychologically and physically. This paper is concerned with the design, sensing and control of a robotic prosthetic eye that moves horizontally in synchronization with the movement of the natural eye. Two generations of robotic prosthetic eye models have been developed. The first generation model uses an external infrared sensor array mounted on the frame of a pair of eyeglasses to detect the natural eye movement and to feed the control system to drive the artificial eye to move with the natural eye. The second generation model removes the impractical usage of the eye glass frame and uses the human brain EOG (electro-ocular-graph signal picked up by electrodes placed on the sides of a person's temple to carry out the same eye movement detection and control tasks as mentioned above. Theoretical issues on sensor failure detection and recovery, and signal processing techniques used in sensor data fusion, are studied using statistical methods and artificial neural network based techniques. In addition, practical control system design and implementation using micro-controllers are studied and implemented to carry out the natural eye movement detection and artificial robotic eye control tasks. Simulation and experimental studies are performed, and the results are included to demonstrate the effectiveness of the research project reported in this paper.

  1. Pressure casting technique for transtibial prosthetic socket fit in developing countries

    Directory of Open Access Journals (Sweden)

    Peter Vee Sin Lee, PhD

    2014-03-01

    Full Text Available This study investigated a low-cost and low-skill dependent pressure casting technique (PCAST to fabricate and fit transtibial (TT prosthetic sockets in a developing country. Thirteen adult volunteers (average age 47 yr with unilateral TT amputation participated. After fitting, five participants were lost to follow-up (four rejected the prosthesis and one died. The eight remaining participants used the prosthesis for an average of 167 +/– 1 d and indicated regular use throughout this period. Success was evaluated by measures of satisfaction (Satisfaction with Prosthesis Questionnaire [SATPRO], physical function, and gait recorded after fitting and following the usage period. SATPRO results showed high levels of satisfaction on both occasions. After the usage period, the timed up-and-go and six-minute walk performances increased by 1.7 +/– 2.0 s and 60 +/– 29 m (p = 0.001, respectively, whereas gait speed, cadence, step and stride length, support base, and percent gait cycle times remained unchanged. The results show that a TT PCAST socket (with some minor modifications was successfully fitted to eight of the participants (success rate of 62%. It is reasonable to conclude that this technique may assist people with TT amputation in a developing country where there is a lack of trained personnel. Importantly, this technique may reduce TT prosthetic costs and increase fitting opportunity in a developing country.

  2. Pressure casting technique for transtibial prosthetic socket fit in developing countries.

    Science.gov (United States)

    Lee, Peter Vee Sin; Lythgo, Noel; Laing, Sheridan; Lavranos, Jimmy; Thanh, Nguyen Hai

    2014-01-01

    This study investigated a low-cost and low-skill dependent pressure casting technique (PCAST) to fabricate and fit transtibial (TT) prosthetic sockets in a developing country. Thirteen adult volunteers (average age 47 yr) with unilateral TT amputation participated. After fitting, five participants were lost to follow-up (four rejected the prosthesis and one died). The eight remaining participants used the prosthesis for an average of 167 +/- 1 d and indicated regular use throughout this period. Success was evaluated by measures of satisfaction (Satisfaction with Prosthesis Questionnaire [SATPRO]), physical function, and gait recorded after fitting and following the usage period. SATPRO results showed high levels of satisfaction on both occasions. After the usage period, the timed up-and-go and six-minute walk performances increased by 1.7 +/- 2.0 s and 60 +/- 29 m (p = 0.001), respectively, whereas gait speed, cadence, step and stride length, support base, and percent gait cycle times remained unchanged. The results show that a TT PCAST socket (with some minor modifications) was successfully fitted to eight of the participants (success rate of 62%). It is reasonable to conclude that this technique may assist people with TT amputation in a developing country where there is a lack of trained personnel. Importantly, this technique may reduce TT prosthetic costs and increase fitting opportunity in a developing country.

  3. Influence of anatomic reference on the buccal contour of prosthetic crowns

    Directory of Open Access Journals (Sweden)

    Flávia Sabrina Queirós Vasconcelos

    2009-09-01

    Full Text Available During clinical practice, when performing prosthetic rehabilitation with single crowns, improper reproduction of the dental contour by the dental laboratory is a common occurrence. Therefore, the present study evaluated the fidelity of the reproduction of the buccal contour in an upper left canine performed by three Dental Prosthesis Technicians (DPT using the indirect laminate veneer technique. First, the DPTs confected the veneers based on a model obtained from the upper arch of a dental dummy, containing a replica of an upper left canine with a prosthetic preparation for a laminate veneer. Then, the same DPTs received other identical models, now with the replica of the upper left canine with no preparation, to be used as an anatomical reference for confecting the laminate veneers. The laminate veneers were then bonded to the plaster models and had their buccal contour individually measured. Measurements were also made of the buccal contour of the reference canine. The data were analyzed by ANOVA and the t-test (p = 0.05. Results showed 100% of buccal overcontour when the laminate veneers were compared to the reference canine, regardless of which DPT confected the veneer and regardless of using or not the anatomical reference. The DPTs who participated in the present study were unable to acomplish a faithful anatomical reproduction of the buccal contour, creating an overcontour in all samples. This situation may be responsible for increasing the probability of periodontal and esthetic harm in clinical practice.

  4. A neurorobotic platform for locomotor prosthetic development in rats and mice

    Science.gov (United States)

    von Zitzewitz, Joachim; Asboth, Leonie; Fumeaux, Nicolas; Hasse, Alexander; Baud, Laetitia; Vallery, Heike; Courtine, Grégoire

    2016-04-01

    Objectives. We aimed to develop a robotic interface capable of providing finely-tuned, multidirectional trunk assistance adjusted in real-time during unconstrained locomotion in rats and mice. Approach. We interfaced a large-scale robotic structure actuated in four degrees of freedom to exchangeable attachment modules exhibiting selective compliance along distinct directions. This combination allowed high-precision force and torque control in multiple directions over a large workspace. We next designed a neurorobotic platform wherein real-time kinematics and physiological signals directly adjust robotic actuation and prosthetic actions. We tested the performance of this platform in both rats and mice with spinal cord injury. Main Results. Kinematic analyses showed that the robotic interface did not impede locomotor movements of lightweight mice that walked freely along paths with changing directions and height profiles. Personalized trunk assistance instantly enabled coordinated locomotion in mice and rats with severe hindlimb motor deficits. Closed-loop control of robotic actuation based on ongoing movement features enabled real-time control of electromyographic activity in anti-gravity muscles during locomotion. Significance. This neurorobotic platform will support the study of the mechanisms underlying the therapeutic effects of locomotor prosthetics and rehabilitation using high-resolution genetic tools in rodent models.

  5. Loading applied on prosthetic knee of transfemoral amputee: comparison of inverse dynamics and direct measurements.

    Science.gov (United States)

    Dumas, R; Cheze, L; Frossard, L

    2009-11-01

    Inverse dynamics is the most comprehensive method that gives access to the net joint forces and moments during walking. However it is based on assumptions (i.e., rigid segments linked by ideal joints) and it is known to be sensitive to the input data (e.g., kinematic derivatives, positions of joint centres and centre of pressure, inertial parameters). Alternatively, transducers can be used to measure directly the load applied on the residuum of transfemoral amputees. So, the purpose of this study was to compare the forces and moments applied on a prosthetic knee measured directly with the ones calculated by three inverse dynamics computations--corresponding to 3 and 2 segments, and "ground reaction vector technique"--during the gait of one patient. The maximum RMSEs between the estimated and directly measured forces (i.e., 56 N) and moment (i.e., 5 N m) were relatively small. However the dynamic outcomes of the prosthetic components (i.e., absorption of the foot, friction and limit stop of the knee) were only partially assessed with inverse dynamic methods.

  6. Effects of Salivary Oxidative Markers on Edentulous Patients’ Satisfaction with Prosthetic Denture Treatments: A Pilot Study

    Science.gov (United States)

    Feng, Sheng-Wei; Miao, Nae-Fang; Lin, Pei-Huan; Lin, Che-Tong; Tsai, Shin-Han; Huang, Yung-Kai

    2016-01-01

    Objectives The purpose of this study was to assess relationships among periodontal conditions, salivary antioxidant levels, and patients’ satisfaction with their prostheses. Methods This study was conducted at the Division of Prosthodontics, Department of Dentistry, Taipei Medical University Hospital. The periodontal condition of patients was based on an assessment of the plaque index (PI) and gingival index (GI). The pH value, flow rate, and buffer capacity of the saliva were estimated. The salivary total antioxidant status (TAS) and superoxide dismutase (SOD) level were also determined. Patients’ satisfaction with prosthetic treatments was evaluated using the Chinese version of the short-form Oral Health Impact Profile (OHIP-14C). A multivariate regression model was used to determine whether patients’ satisfaction with prosthetic treatment was affected by their oral health status. Results In total, 35 edentulous patients were recruited. In the Spearman correlation analysis, salivary pH (r = -0.36, p = 0.03) and the buffer ability (r = -0.48, pedentulous patients. PMID:26986841

  7. Actuation mechanisms of carbon nanotube-based architectures

    Science.gov (United States)

    Geier, Sebastian; Mahrholz, Thorsten; Wierach, Peter; Sinapius, Michael

    2016-04-01

    State of the art smart materials such as piezo ceramics or electroactive polymers cannot feature both, mechanical stiffness and high active strain. Moreover, properties like low density, high mechanical stiffness and high strain at the same time driven by low energy play an increasingly important role for their future application. Carbon nanotubes (CNT), show this behavior. Their active behavior was observed 1999 the first time using paper-like mats made of CNT. Therefore the CNT-papers are electrical charged within an electrolyte thus forming a double- layer. The measured deflection of CNT material is based on the interaction between the charged high surface area formed by carbon nanotubes and ions provided by the electrolyte. Although CNT-papers have been extensively analyzed as well at the macro-scale as nano-scale there is still no generally accepted theory for the actuation mechanism. This paper focuses on investigations of the actuation mechanisms of CNT-papers in comparison to vertically aligned CNT-arrays. One reason of divergent results found in literature might be attributed to different types of CNT samples. While CNT-papers represent architectures of short CNTs which need to bridge each other to form the dimensions of the sample, the continuous CNTs of the array feature a length of almost 3 mm, along which the experiments are carried out. Both sample types are tested within an actuated tensile test set-up under different conditions. While the CNT-papers are tested in water-based electrolytes with comparably small redox-windows the hydrophobic CNT-arrays are tested in ionic liquids with comparatively larger redox-ranges. Furthermore an in-situ micro tensile test within an SEM is carried out to prove the optimized orientation of the MWCNTs as result of external load. It was found that the performance of CNT-papers strongly depends on the test conditions. However, the CNT-arrays are almost unaffected by the conditions showing active response at negative

  8. Mitral isthmus ablation in patients with prosthetic mitral valves

    Institute of Scientific and Technical Information of China (English)

    LONG De-yong; MA Chang-sheng; JIANG Hong; DONG Jian-zeng; LIU Xing-peng; HUANG He; TANG Yan-hong; WU Gang; HUANG Cong-xin

    2010-01-01

    Background Previous studies have investigated the technique of linear ablation at the mitral isthmus (MI) in patients with idopathic atrial fibrillation (AF), but MI ablation in patients with prosthetic natural mitral valves (MVs) was not described in detail. Present study sought to summarize our initial experience of ablating MI in patients with prosthetic MVs Methods Patients with drug refractory AF and prosthetic MVs were eligible for this study, and the patients with natural MVs but received MI ablation served as control group. Left atrium (LA) mapping and ablation was carried out guided by CARTO system. The anatomy of MI was assessed via computer topography scan.Results During the study period, a consecutive of 19 patients (male/female=12/7, mean age of (48±-6) years) with prosthetic MVs (16 with metal valves, 3 with biologic valves) entered for AF ablation, other 35 patients served as control group. In study group, mapping along MI documented lower voltages ((2.0±1.0) vs. (3.1±1.3) mV, P=0.002), more fragmented potentials (19/19 vs. 20/15, P<0.001 ), and higher impedance ((132±34) vs. (110±20) Ω, P=0.004). After initial ablation, more residual gaps along the MI lesions were found in study group (2.4±0.4 vs. 1.7±0.3, P <0.001). The mean length of MI ((6.2±3.3) vs. (7.1±2.3) cm, P=0.25) was comparable between 2 groups, but the MI in study group was much thicker ((3.1 ±1.8) vs. (2.1±1.07) cm, P=0.01 ) and all were found as pouch type (19/19 vs. 2/35, P <0.001). The follow-up results were comparable (65.1% vs. 72.3%, P=0.30).Conclusion For patients with prosthetic MVs, linear ablation at MI could be successfully carried out despite anatomical and pathological changes.

  9. A survey of prosthetic eye wearers to investigate mucoid discharge

    Directory of Open Access Journals (Sweden)

    Pine K

    2012-05-01

    Full Text Available Keith Pine1, Brian Sloan2, Joanna Stewart3, Robert J Jacobs11Department of Optometry and Vision Science, 2Department of Ophthalmology, New Zealand National Eye Centre, 3Section of Epidemiology and Biostatistics, School of Population Health, University of Auckland, Auckland, New ZealandBackground: This study aimed to better understand the causes and treatments of mucoid discharge associated with prosthetic eye wear by reviewing the literature and surveying anophthalmic patients.Methods: An anonymous questionnaire was completed by 429 prosthetic eye wearers who used visual analog scales to self-measure their discharge experience for four discharge characteristics: frequency, color, volume, and viscosity. These characteristics were analyzed with age, ethnicity, years wearing a prosthesis, eye loss cause, removal and cleaning regimes, hand-washing behavior, age of current prosthesis, and professional repolishing regimes as explanatory variables. Eighteen ocularists’ Web sites containing comments on the cause and treatment of discharge were surveyed.Results: Associations were found between discharge frequency and cleaning regimes with more frequent cleaning accompanying more frequent discharge. Color was associated with years of wearing and age, with more years of wearing and older people having less colored discharge. Volume was associated with cleaning regimes with more frequent cleaners having more volume. Viscosity was associated with cleaning regimes and years of wearing with more frequent cleaning and shorter wearing time accompanying more viscous discharge. No associations were found between discharge characteristics and ethnicity, eye loss cause, hand washing, age of current prosthesis, or repolishing regimes. Forty-seven percent of ocularists’ Web sites advised that discharge was caused by surface deposits on the prosthesis, 29% by excessive handling of the prosthesis, and 24% by other causes.Conclusions: A standardized treatment

  10. Novel Method to Evaluate Angular Stiffness of Prosthetic Feet From Linear Compression Tests

    OpenAIRE

    Adamczyk, Peter G.; Roland, Michelle; Hahn, Michael E.

    2013-01-01

    Lower limb amputee gait during stance phase is related to the angular stiffness of the prosthetic foot, which describes the dependence of ankle torque on angular progression of the shank. However, there is little data on angular stiffness of prosthetic feet, and no method to directly measure it has been described. The objective of this study was to derive and evaluate a method to estimate the angular stiffness of prosthetic feet using a simple linear compression test. Linear vertical compress...

  11. JRRD Then & Now: VA Prosthetic and Sensory Aids Service—65 Years of Progress

    OpenAIRE

    Lucille Beck, PhD

    2013-01-01

    The JRRD article written by Stewart in 1965 entitled “Twenty Years of Progress” highlighted the progress of the Veteran Administration’s Prosthetic and Sensory Aids Service since World War II. Recognizing the importance of prosthetic and sensory aids to Veteran healthcare during those early days set the foundation for the department of today to become the largest and most comprehensive provider of prosthetic devices and sensory aids in the world.

  12. Erosion mechanism and erosion products in carbon-based materials

    Energy Technology Data Exchange (ETDEWEB)

    Arkhipov, N.; Bakhtin, V.; Barsuk, V.; Kurkin, S.; Mironova, E.; Piazza, G.; Safronov, V. E-mail: vsafr@rico.ttk.ru; Scaffidi-Argentina, F.; Toporkov, D.; Vasenin, S.; Wuerz, H.; Zhitlukhin, A

    2002-12-01

    Plasma/material interaction was studied in disruption simulation experiments at the plasma gun facility MK-200. Graphite and carbon-fibre composites were exposed to pulsed energetic plasma under heat loads typically expected for disruptions in future tokamaks. Erosion rates, erosion mechanisms and the properties of the eroded carbon have been studied.

  13. A study on the cytotoxicity of carbon-based materials.

    Science.gov (United States)

    Saha, Dipendu; Heldt, Caryn L; Gencoglu, Maria F; Vijayaragavan, K Saagar; Chen, Jihua; Saksule, Ashish

    2016-11-01

    With an aim to understand the origin and key contributing factors towards carbon-induced cytotoxicity, we have studied five different carbon samples with diverse surface area, pore width, shape and size, conductivity and surface functionality. All the carbon materials were characterized with surface area and pore size distribution, X-ray photoelectron spectroscopy (XPS) and electron microscopic imaging. We performed cytotoxicity study in Caco-2 cells by colorimetric assay, oxidative stress analysis by reactive oxygen species (ROS) detection, cellular metabolic activity measurement by adenosine triphosphate (ATP) depletion and visualization of cellular internalization by TEM imaging. The carbon materials demonstrated a varying degree of cytotoxicity in contact with Caco-2 cells. The lowest cell survival rate was observed for nanographene, which possessed the minimal size amongst all the carbon samples under this study. None of the carbons induced oxidative stress to the cells as indicated by the ROS generation results. Cellular metabolic activity study revealed that the carbon materials caused ATP depletion in cells and nanographene caused the highest depletion. Visual observation by TEM imaging indicated the cellular internalization of nanographene. This study confirmed that the size is the key cause of carbon-induced cytotoxicity and it is probably caused by the ATP depletion within the cell. PMID:27524001

  14. Essays on the economics of forestry-based carbon mitigation

    NARCIS (Netherlands)

    Benítez-Ponce, P.C.

    2005-01-01

    Keywords:climate change, carbon costs, afforestation, risk, secondary forests, conservation payments, ecosystem services

    This thesis is a collection of articles that deal with the economics of carbon sequestration in forests. It pays

  15. Efficacy of proprioceptive neuromuscular facilitation techniques versus traditional prosthetic training for improving ambulatory function in transtibial amputees

    Directory of Open Access Journals (Sweden)

    Pallavi Sahay, MPT

    2014-06-01

    Full Text Available The objective of this randomized controlled trial was to evaluate the efficacy of proprioceptive neuromuscular facilitation (PNF techniques in comparison to traditional prosthetic training (TPT in improving ambulatory function in transtibial amputees. Thirty study participants (19 men and 11 women with unilateral transtibial amputation participated in the study. They were randomly allocated to either the traditional training group (i.e., TPT (n = 15 or the PNF training group (n = 15. The treatment in the TPT group consisted of weight-bearing, weight-shifting, balance, and gait exercises for 30 minutes daily for 10 treatment sessions. In the PNF group, the same activities were performed by employing PNF principles and techniques. The outcome measures were gait parameters (e.g., stride width, step length, and stride length and the Locomotor Capabilities Index (LCI. The between-group comparisons at the end of the trial showed that the PNF group showed significant improvement in gait parameters and in the LCI, compared to the TPT group (p < 0.05. The results of the study suggested that prosthetic training based on proprioceptive feedback is more effective than the traditional prosthetic programme in improving ambulatory function.

  16. Carbon Nanotube-Based Structural Health Monitoring Sensors

    Science.gov (United States)

    Wincheski, Russell; Jordan, Jeffrey; Oglesby, Donald; Watkins, Anthony; Patry, JoAnne; Smits, Jan; Williams, Phillip

    2011-01-01

    Carbon nanotube (CNT)-based sensors for structural health monitoring (SHM) can be embedded in structures of all geometries to monitor conditions both inside and at the surface of the structure to continuously sense changes. These CNTs can be manipulated into specific orientations to create small, powerful, and flexible sensors. One of the sensors is a highly flexible sensor for crack growth detection and strain field mapping that features a very dense and highly ordered array of single-walled CNTs. CNT structural health sensors can be mass-produced, are inexpensive, can be packaged in small sizes (0.5 micron(sup 2)), require less power than electronic or piezoelectric transducers, and produce less waste heat per square centimeter than electronic or piezoelectric transducers. Chemically functionalized lithographic patterns are used to deposit and align the CNTs onto metallic electrodes. This method consistently produces aligned CNTs in the defined locations. Using photo- and electron-beam lithography, simple Cr/Au thin-film circuits are patterned onto oxidized silicon substrates. The samples are then re-patterned with a CNT-attracting, self-assembled monolayer of 3-aminopropyltriethoxysilane (APTES) to delineate the desired CNT locations between electrodes. During the deposition of the solution-suspended single- wall CNTs, the application of an electric field to the metallic contacts causes alignment of the CNTs along the field direction. This innovation is a prime candidate for smart skin technologies with applications ranging from military, to aerospace, to private industry.

  17. Carbon nanotube thin film transistors based on aerosol methods

    International Nuclear Information System (INIS)

    We demonstrate a fabrication method for high-performance field-effect transistors (FETs) based on dry-processed random single-walled carbon nanotube networks (CNTNs) deposited at room temperature. This method is an advantageous alternative to solution-processed and direct CVD grown CNTN FETs, which allows using various substrate materials, including heat-intolerant plastic substrates, and enables an efficient, density-controlled, scalable deposition of as-produced single-walled CNTNs on the substrate directly from the aerosol (floating catalyst) synthesis reactor. Two types of thin film transistor (TFT) structures were fabricated to evaluate the FET performance of dry-processed CNTNs: bottom-gate transistors on Si/SiO2 substrates and top-gate transistors on polymer substrates. Devices exhibited on/off ratios up to 105 and field-effect mobilities up to 4 cm2 V-1 s-1. The suppression of hysteresis in the bottom-gate device transfer characteristics by means of thermal treatment in vacuum and passivation by an atomic layer deposited Al2O3 film was investigated. A 32 nm thick Al2O3 layer was found to be able to eliminate the hysteresis.

  18. Nonlinear behaviour of electrostatically actuated carbon nanotube-based devices

    International Nuclear Information System (INIS)

    In this paper nonlinear behaviour of electrostatically actuated carbon nanotubes (CNTs) is investigated. The model comprises a clamped-clamped CNT suspended over a graphite ground electrode plate from which a potential difference is imposed. The actuation is based on ac and dc applied voltages and it is assumed that the neutral axis of bending is stretched when the beam is deflected, and also, the interatomic interaction forces between CNT and ground plate are considered. The versatile Galerkin's method is employed to reduce the nonlinear integral-partial-differential equation of motion to a nonlinear ordinary differential equation in time, and then, the reduced equation is solved by direct numerical integration. In the dc voltage actuation case, the pull-in/pull-out phenomena, hysteresis characteristic, pull-in time duration and the response of the system are studied. The obtained results are compared with the molecular dynamics method. Eventually, a nano-switch immune to input noise is proposed, which relies on the hysteresis characteristic of the system. In combined ac and dc voltage actuations, the vibrational behaviour and nonlinear frequency response of nano-resonator are studied.

  19. Carbon nanotube-cuprous oxide composite based pressure sensors

    Institute of Scientific and Technical Information of China (English)

    Kh. S. Karimov; Muhammad Tariq Saeed Chani; Fazal Ahmad Khalid; Adam Khan; Rahim Khan

    2012-01-01

    In this paper,we present the design,the fabrication,and the experimental results of carbon nanotube (CNT) and Cu2O composite based pressure sensors.The pressed tablets of the CNT-Cu2O composite are fabricated at a pressure of 353 MPa.The diameters of the multiwalled nanotubes (MWNTs) are between 10 nm and 30 nm.The sizes of the Cu2O micro particles are in the range of 3-4 μrn.The average diameter and the average thickness of the pressed tablets are 10 mm and 4.0 mm,respectively.In order to make low resistance electric contacts,the two sides of the pressed tablet are covered by silver pastes.The direct current resistance of the pressure sensor decreases by 3.3 times as the pressure increases up to 37 kN/m2.The simulation result of the resistance-pressure relationship is in good agreement with the experimental result within a variation of ±2%.

  20. Pregnancy with prosthetic heart valves - 30 years' nationwide experience in Denmark

    DEFF Research Database (Denmark)

    Sillesen, Martin; Hjortdal, Vibeke; Vejlstrup, Niels;

    2011-01-01

    Pregnancy in women with prosthetic heart valves remains a risk factor for both mother and fetus, but unselected and unbiased outcome and complication data remain scarce. We analyzed nationwide outcome data from 1977 to 2007 for all pregnancies in women with prosthetic valves.......Pregnancy in women with prosthetic heart valves remains a risk factor for both mother and fetus, but unselected and unbiased outcome and complication data remain scarce. We analyzed nationwide outcome data from 1977 to 2007 for all pregnancies in women with prosthetic valves....

  1. Activated carbon and single-walled carbon nanotube based electrochemical capacitor in 1 M LiPF{sub 6} electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Azam, M.A., E-mail: asyadi@utem.edu.my [Carbon Research Technology Research Group, Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka (Malaysia); Jantan, N.H.; Dorah, N.; Seman, R.N.A.R.; Manaf, N.S.A. [Carbon Research Technology Research Group, Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka (Malaysia); Kudin, T.I.T. [Ionics Materials & Devices Research Laboratory, Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, Selangor (Malaysia); Yahya, M.Z.A. [Ionics Materials & Devices Research Laboratory, Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, Selangor (Malaysia); National Defence University of Malaysia, Kem Sungai Besi, 57000 Kuala Lumpur (Malaysia)

    2015-09-15

    Highlights: • Activated carbon and single-walled CNT based electrochemical capacitor. • Electrochemical analysis by means of CV, charge/discharge and impedance. • 1 M LiPF{sub 6} non-aqueous solution as an electrolyte. • AC/SWCNT electrode exhibits a maximum capacitance of 60.97 F g{sup −1}. - Abstract: Carbon nanotubes have been extensively studied because of their wide range of potential application such as in nanoscale electric circuits, textiles, transportation, health, and the environment. Carbon nanotubes feature extraordinary properties, such as electrical conductivities higher than those of copper, hardness and thermal conductivity higher than those of diamond, and strength surpassing that of steel, among others. This research focuses on the fabrication of an energy storage device, namely, an electrochemical capacitor, by using carbon materials, i.e., activated carbon and single-walled carbon nanotubes, of a specific weight ratio as electrode materials. The electrolyte functioning as an ion carrier is 1 M lithium hexafluorophosphate. Variations in the electrochemical performance of the device, including its capacitance, charge/discharge characteristics, and impedance, are reported in this paper. The electrode proposed in this work exhibits a maximum capacitance of 60.97 F g{sup −1} at a scan rate of 1 mV s{sup −1}.

  2. Activated carbon and single-walled carbon nanotube based electrochemical capacitor in 1 M LiPF6 electrolyte

    International Nuclear Information System (INIS)

    Highlights: • Activated carbon and single-walled CNT based electrochemical capacitor. • Electrochemical analysis by means of CV, charge/discharge and impedance. • 1 M LiPF6 non-aqueous solution as an electrolyte. • AC/SWCNT electrode exhibits a maximum capacitance of 60.97 F g−1. - Abstract: Carbon nanotubes have been extensively studied because of their wide range of potential application such as in nanoscale electric circuits, textiles, transportation, health, and the environment. Carbon nanotubes feature extraordinary properties, such as electrical conductivities higher than those of copper, hardness and thermal conductivity higher than those of diamond, and strength surpassing that of steel, among others. This research focuses on the fabrication of an energy storage device, namely, an electrochemical capacitor, by using carbon materials, i.e., activated carbon and single-walled carbon nanotubes, of a specific weight ratio as electrode materials. The electrolyte functioning as an ion carrier is 1 M lithium hexafluorophosphate. Variations in the electrochemical performance of the device, including its capacitance, charge/discharge characteristics, and impedance, are reported in this paper. The electrode proposed in this work exhibits a maximum capacitance of 60.97 F g−1 at a scan rate of 1 mV s−1

  3. Fluoroethylene Carbonate Addition Effect on Electrochemical Properties of Mixed Carbonate-based Organic Electrolyte Solution for a Capacitor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mingyeong; Kim, Seok [Pusan National Univ., Busan (Korea, Republic of); Kim, Ickjun; Yang, Sunhye [Korea Electrotechnology Research Institute, Changwon (Korea, Republic of)

    2014-02-15

    In this paper, organic solvent electrolytes were prepared by a mixture of propylene carbonate (PC), dimethyl carbonate (DMC), tetraethylammonium tetrafluoroborate (TEABF{sub 4}) as a salt, and by containing a different content of fluoroethylene carbonate (FEC) as an additive agenT{sup -} The aim of this paper is to evaluate the ionic properties of propylene carbonate (PC)/dimethyl carbonate (DMC) mixtures as solvents for a capacitor application, in view of improving the electrochemical performances. The bulk resistance and interfacial resistance of the mixture electrolytes were investigated using an AC impedance method. The morphology of carbon-based electrodes which were contained in different electrolytes was analyzed by scanning electron microscopy (SEM) method. From the experimental results, by increasing the FEC content, capacitance of electrodes was increased, and the interfacial resistance was decreased. In particular, by a content of 2 vol % FEC in 0.2 M TEABF{sub 4} PC/DMC solvent, the electrolyte showed the superior capacitance. However, when FEC content exceeds 2 vol %, the capacitance was decreased and the interfacial resistance was increased.

  4. States of Carbon Nanotube Supported Mo-Based HDS Catalysts

    Institute of Scientific and Technical Information of China (English)

    Hongyan Shang; Chenguang Liu; Yongqiang Xu; Jieshan Qiu; Fei Wei

    2006-01-01

    The dispersion of the active phase and loading capacity of the Mo species on carbon nanotube (CNT) was studied by the XRD technique. The reducibility properties of Co-Mo catalysts in the oxide state over CNTs were investigated by TPR, while the sulfided Co-Mo/CNT catalysts were characterized by means of the XRD and LRS techniques. The activity and selectivity with respect to the hydrodesulfurization (HDS) performances on carbon nanotube supported Co-Mo catalysts were evaluated. It was found that the main active molybdenum species in the oxide state MoO3/CNT catalysts were MoO2, but not MoO3, as generally expected. The maximum loading before the formation of the bulk phase was lower than 6% (percent by mass, based on MoO3). TPR studies revealed that the active species in the oxide state Co-Mo/CNT catalysts were reduced more easily at relatively lower temperatures in comparison to those of the Co-Mo/γ-Al2O3 catalysts, indicating that the CNT support promoted or favored the reduction of the active species. The active species of a Co-Mo-0.7/CNT catalyst were more easily reduced than those of the Co-Mo/CNT catalysts with Co/Mo atomic ratios of 0.2, 0.35, and 0.5, respectively, suggesting that the Co/Mo atomic ratio has a great effect on the reducibility of the active species. It was found that the incorporation of cobalt improved the dispersion of the molybdenum species on the support, and a phenomenon of mobilization and re-dispersion had occurred during the sulfurization process, resulting in low valence state Mo3S4 and Co-MoS2.17 active phases. HDS measurements showed that the Co-Mo/CNT catalysts were more active than the Co-Mo/γ-Al2O3 ones for the desulfurization of DBT, and the hydrogenolysis/hydrogenation selectivity of the Co-Mo/CNT catalysts was also much higher than those of the Co-Mo/γ-Al2O3. The Co-Mo/CNT catalyst with a Co/Mo atomic ratio of 0.7 showed the highest activity, whereas the catalyst with a Co/Mo atomic ratio of 0.35 had the highest selectivity.

  5. Thermally Conductive Tape Based on Carbon Nanotube Arrays

    Science.gov (United States)

    Kashani, Ali

    2011-01-01

    To increase contact conductance between two mating surfaces, a conductive tape has been developed by growing dense arrays of carbon nanotubes (CNTs, graphite layers folded into cylinders) on both sides of a thermally conductive metallic foil. When the two mating surfaces are brought into contact with the conductive tape in between, the CNT arrays will adhere to the mating surface. The van der Waals force between the contacting tubes and the mating surface provides adhesion between the two mating surfaces. Even though the thermal contact conductance of a single tube-to-tube contact is small, the tremendous amount of CNTs on the surface leads to a very large overall contact conductance. Interface contact thermal resistance rises from the microroughness and the macroscopic non-planar quality of mating surfaces. When two surfaces come into contact with each other, the actual contact area may be much less than the total area of the surfaces. The real area of contact depends on the load, the surface roughness, and the elastic and inelastic properties of the surface. This issue is even more important at cryogenic temperatures, where materials become hard and brittle and vacuum is used, which prevents any gas conduction through the interstitial region. A typical approach to increase thermal contact conductance is to use thermally conducting epoxies or greases, which are not always compatible with vacuum conditions. In addition, the thermal conductivities of these compounds are often relatively low. The CNTs used in this approach can be metallic or semiconducting, depending on the folding angle and diameter. The electrical resistivity of multiwalled carbon nanotubes (MWCNTs) has been reported. MWCNTs can pass a current density and remain stable at high temperatures in air. The thermal conductivity of a MWCNT at room temperature is measured to be approximately 3,000 W/m-K, which is much larger than that of diamond. At room temperature, the thermal conductance of a 0.3 sq cm

  6. Structural evolution of Eucalyptus tar pitch-based carbons during carbonization

    International Nuclear Information System (INIS)

    Wood tar pitches are generated as by-products by the charcoal manufacturing industry. They have a macromolecular structure constituted mainly by phenolic, guaiacylic, and siringylic units common to lignin. Due to their characteristics, biopitches are been investigated as precursors of carbon materials such as carbon fibers, bioelectrodes and activated carbons. In the present work the structural evolution of Eucalyptus tar pitches under carbonization is investigated, which is important for the improvement of planning and control of pitch processing and end-product properties during carbon material production. The studies involve X-ray diffraction and infrared analyses, besides helium density, BET surface area and BJH pore volume measurements. The results showed that the conversion of pitch into carbon basically involves three steps: (1) Up to around 600 deg C the material has an highly disordered structure, being the release of aliphatic side chains and volatiles the main events taking place. (2) Between 600 deg C and 800 deg C, condensation of aromatic rings occurs to form bi-dimensional hexagonal networks so that micro- and mesoporosity are developed. The 800 deg C-coke is constituted by two phases: one highly disordered and another more crystalline. (3) Over 800 deg C, both phases are gradually ordered. As defects are gradually removed, surface area and porosity decrease, approaching zero for the 2100 deg C-coke

  7. Multiscale Hybrid Micro-Nanocomposites Based on Carbon Nanotubes and Carbon Fibers

    Directory of Open Access Journals (Sweden)

    Fawad Inam

    2010-01-01

    Full Text Available Amino-modified double wall carbon nanotube (DWCNT-NH2/carbon fiber (CF/epoxy hybrid micro-nanocomposite laminates were prepared by a resin infusion technique. DWCNT-NH2/epoxy nanocomposites and carbon fiber/epoxy microcomposites were made for comparison. Morphological analysis of the hybrid composites was performed using field emission scanning electron microscope. A good dispersion at low loadings of carbon nanotubes (CNTs in epoxy matrix was achieved by a bath ultrasonication method. Mechanical characterization of the hybrid micro-nanocomposites manufactured by a resin infusion process included three-point bending, mode I interlaminar toughness, dynamic mechanical analysis, and drop-weight impact testing. The addition of small amounts of CNTs (0.025, 0.05, and 0.1 wt% to epoxy resins for the fabrication of multiscale carbon fiber composites resulted in a maximum enhancement in flexural modulus by 35%, a 5% improvement in flexural strength, a 6% improvement in absorbed impact energy, and 23% decrease in the mode I interlaminar toughness. Hybridization of carbon fiber-reinforced epoxy using CNTs resulted in a reduction in and dampening characteristics, presumably as a result of the presence of micron-sized agglomerates.

  8. Carbon nanotube-based functional materials for optical limiting.

    Science.gov (United States)

    Chen, Yu; Lin, Ying; Liu, Ying; Doyle, James; He, Nan; Zhuang, Xiaodong; Bai, Jinrui; Blau, Werner J

    2007-01-01

    Optical limiting is an important application of nonlinear optics, useful for the protection of human eyes, optical elements, and optical sensors from intense laser pulses. An optical limiter is such a device that strongly attenuates high intensity light and potentially damaging light such as focused laser beams, whilst allowing for the high transmission of ambient light. Optical limiting properties of carbon nanotube suspensions, solubilized carbon nanotubes, small molecules doped carbon nanotubes and polymer/carbon nanotube composites have been reviewed. The optical limiting responses of carbon nanotube suspensions are shown to be dominated by nonlinear scattering as a result of thermally induced solvent-bubble formation and sublimation of the nanotubes, while the solubilized carbon nanotubes optically limit through nonlinear absorption mechanism and exhibit significant solution-concentration-dependent optical limiting responses. In the former case the optical limiting results are independent of nanotube concentrations at the same linear transmittance as that of the solubilized systems. Many efforts have been invested into the research of polymer/carbon nanotube composites in an attempt to allow for the fabrication of films required for the use of nanotubes in a real optical limiting application. The higher carbon nanotube content samples block the incident light more effectively at higher incident energy densities or intensities. The optical limiting mechanism of these composite materials is quite complicated. Besides nonlinear scattering contribution to the optical limiting, there may also be other contributions e.g., nonlinear absorption, nonlinear refraction, electronic absorption and others to the optical limiting. Further improvements in the optical limiting efficiency of the composites and in the dispersion and alignment properties of carbon nanotubes in the polymer matrix could be realized by variation of both nanostructured guest and polymer host, and by

  9. Highly effective metal vapor absorbents based on carbon nanotubes

    Science.gov (United States)

    Liu, Zongwen; Gao, Yihua; Bando, Yoshio

    2002-12-01

    It was shown that, when filled with gallium, carbon nanotubes can absorb copper vapor with extraordinarily high efficiency. The copper vapor generated from the supporting copper grid upon heating to 800 °C in an electron microscope under a pressure of 1.0×10-5 Pa quickly deposited into the carbon nanotubes and formed an alloy with gallium where the vapor pressure is up to 500 times higher (5×10-3 Pa). These filled carbon nanotubes may be used as highly sensitive toxic or radioactive metal vapor absorbents since gallium also tends to form alloys with metals like mercury and uranium.

  10. Solution-based carbohydrate synthesis of individual solid, hollow, and porous carbon nanospheres using spray pyrolysis.

    Science.gov (United States)

    Wang, Chengwei; Wang, Yuan; Graser, Jake; Zhao, Ran; Gao, Fei; O'Connell, Michael J

    2013-12-23

    A facile and scalable solution-based, spray pyrolysis synthesis technique was used to synthesize individual carbon nanospheres with specific surface area (SSA) up to 1106 m(2)/g using a novel metal-salt catalyzed reaction. The carbon nanosphere diameters were tunable from 10 nm to several micrometers by varying the precursor concentrations. Solid, hollow, and porous carbon nanospheres were achieved by simply varying the ratio of catalyst and carbon source without using any templates. These hollow carbon nanospheres showed adsorption of to 300 mg of dye per gram of carbon, which is more than 15 times higher than that observed for conventional carbon black particles. When evaluated as supercapacitor electrode materials, specific capacitances of up to 112 F/g at a current density of 0.1 A/g were observed, with no capacitance loss after 20,000 cycles.

  11. Factors influencing high voltage performance of coconut char derived carbon based electrical double layer capacitor made using acetonitrile and propylene carbonate based electrolytes

    Science.gov (United States)

    Hu, Changzheng; Qu, Weiguo; Rajagopalan, Ramakrishnan; Randall, Clive

    2014-12-01

    Symmetric EDLCs made using high purity carbon electrodes derived from coconut char were tested using 1 M Tetraethylammonium hexafluorophosphate dissolved in two different solvents namely acetonitrile and propylene carbonate. The cell voltage of the capacitor made using propylene carbonate can be extended to 3.5 V and it exhibited good cycling and thermal stability upto 70 °C while the voltage was limited to below 3.0 V in acetonitrile. XPS analysis of the positive and negative electrodes of EDLCs post cycling showed that the primary degradation products were related to ring opening reactions in propylene carbonate based electrolytes while water played a key role in degradation of acetonitrile based EDLCs.

  12. Developing inorganic carbon-based radiocarbon chronologies for Holocene lake sediments in arid NW China

    Science.gov (United States)

    Zhang, Jiawu; Ma, Xueyang; Qiang, Mingrui; Huang, Xiaozhong; Li, Shuang; Guo, Xiaoyan; Henderson, Andrew C. G.; Holmes, Jonathan A.; Chen, Fahu

    2016-07-01

    Inorganic carbonates are often used to establish radiocarbon (14C) chronologies for lake sediments when terrestrial plant remains (TPR) are rare or when bulk organic matter is insufficient for dating, a problem that is common for many lakes in arid regions. However, the reservoir effect (RE), as well as old carbon contributed from the lakes catchment make it difficult to establish reliable chronologies. Here we present a systematic study of inorganic 14C ages of two lake-sediment sequences, one from a small-enclosed saline lake - Lake Gahai in Qaidam Basin, and the other from a large freshwater lake - Lake Bosten in Xinjiang. Modern dissolved inorganic carbon (DIC) of the lakes, paleo-lake sediments exposed in the catchment, and mollusk shells in core sediments from Lake Gahai were dated to assess the RE and the contribution of pre-aged carbon to the old ages in the cores. We propose a statistical regression to assess more than one RE for the 14C carbonate ages within our sedimentary sequences. Old radiocarbon ages contributed by detrital carbonates were assessed by comparing the ages of mollusk shells with those of carbonates at the same sediment depths. We established the RE of the authigenic component and assessed detrital old carbon contributions to our two sites, and this was used to correct the 14C ages. Based on this approach, we developed age models for both cores, and tested them using 210Pb ages in both cores and TPR-based 14C-ages recovered from Lake Bosten. We further tested our age models by comparing carbonate-based oxygen isotope (δ18O) records from both lakes to an independently-dated regional speleothem δ18O record. Our results suggest if sedimentary sequences are densely dated and the RE and the contribution of old carbon from detrital carbonates can be ascertained, robust chronological frameworks based on carbonate-based 14C determinations can be established.

  13. Multifunctional structural supercapacitor composites based on carbon aerogel modified high performance carbon fiber fabric.

    Science.gov (United States)

    Qian, Hui; Kucernak, Anthony R; Greenhalgh, Emile S; Bismarck, Alexander; Shaffer, Milo S P

    2013-07-10

    A novel multifunctional material has been designed to provide excellent mechanical properties while possessing a high electrochemical surface area suitable for electrochemical energy storage: structural carbon fiber fabrics are embedded in a continuous network of carbon aerogel (CAG) to form a coherent but porous monolith. The CAG-modification process was found to be scalable and to be compatible with a range of carbon fiber fabrics with different surface properties. The incorporation of CAG significantly increased the surface area of carbon fiber fabrics, and hence the electrochemical performance, by around 100-fold, resulting in a CAG-normalized specific electrode capacitance of around 62 F g(-1), determined by cyclic voltammetry in an aqueous electrolyte. Using an ionic liquid (IL) electrolyte, the estimated energy density increased from 0.003 to 1 Wh kg(-1), after introducing the CAG into the carbon fiber fabric. 'Proof-of-concept' multifunctional structural supercapacitor devices were fabricated using an IL-modified solid-state polymer electrolyte as a multifunctional matrix to provide both ionic transport and physical support for the primary fibers. Two CAG-impregnated carbon fabrics were sandwiched around an insulating separator to form a functioning structural electrochemical double layer capacitor composite. The CAG-modification not only improved the electrochemical surface area, but also reinforced the polymer matrix surrounding the primary fibers, leading to dramatic improvements in the matrix-dominated composite properties. Increases in in-plane shear strength and modulus, of up to 4.5-fold, were observed, demonstrating that CAG-modified structural carbon fiber fabrics have promise in both pure structural and multifunctional energy storage applications.

  14. DC conductivity of silicon nitride based carbon-ceramic composites

    Directory of Open Access Journals (Sweden)

    B. Fényi

    2007-12-01

    Full Text Available The silicon nitride ceramics are usually known as strongly refractory and enduring materials and have typical electrically insulating properties. If the reinforcing phase of ceramic composite (that is mainly put in the material to improve mechanical properties is a good electrical conductor, it is worth to investigate the composite in electrical aspect. In this work carbon nanotubes, black-carbon and graphite were added to the basic silicon nitride ceramic and the electrical conductivity of the prepared carbon-ceramic composites was determined. The conductivity of the ceramic composites with different type and concentration of the carbon additives was observed by applying four point DC resistance measurements. Insulator and conductor composites in a wide conductivity range can be produced depending on the type and quantity of the additives. The additive types as well as the sintering parameters have influence on the basic electrical properties of the conductor composites.

  15. Natural Gas Based Electricity Production and Low Carbon Technology Options

    Science.gov (United States)

    Concerns regarding air quality, global climate change, and the national energy security impacts of the intensive use of fossil fuels and their environmental impacts in the power generation sector have raised interest in alternative low carbon electricity generation technology and...

  16. Techno-economic evaluation of different CO2-based processes for dimethyl carbonate production

    DEFF Research Database (Denmark)

    Kongpanna, Pichayapan; Pavarajarn, Varong; Gani, Rafiqul;

    2015-01-01

    ; and (4) synthesis from ethylene carbonate. The processes avoid the use of toxic chemicals such as phosgene, CO and NO that are required in conventional DMC production processes. From preliminary thermodynamic analysis, the yields of DMC are found to have the following order (higher to lower): ethylene......In this work, several chemical processes for production of dimethyl carbonate (DMC) based on CO2 utilization are evaluated. Four CO2-based processes for production of DMC are considered: (1) direct synthesis from CO2 and methanol; (2) synthesis from urea; (3) synthesis from propylene carbonate...... carbonate route > urea route > propylene carbonate route > direct synthesis from CO2. Therefore, only the urea and ethylene carbonate routes are further investigated by comparing their performances with the commercial BAYER process on the basis of kg of DMC produced at a specific purity. The ethylene...

  17. A catechol biosensor based on electrospun carbon nanofibers

    OpenAIRE

    Dawei Li; Zengyuan Pang; Xiaodong Chen; Lei Luo; Yibing Cai; Qufu Wei

    2014-01-01

    Carbon nanofibers (CNFs) were prepared by combining electrospinning with a high-temperature carbonization technique. And a polyphenol biosensor was fabricated by blending the obtained CNFs with laccase and Nafion. Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscope (FE-SEM) were, respectively, employed to investigate the structures and morphologies of the CNFs and of the mixtures. Cyclic voltammetry and chronoamperometry were empl...

  18. Microstructure and surface properties of lignocellulosic-based activated carbons

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Garcia, P., E-mail: pegonzal@quim.ucm.es [Departamento de Quimica Inorganica, Facultad de Ciencias Quimicas, Universidad Complutense, E-28040, Madrid (Spain); Centeno, T.A. [Instituto Nacional del Carbon-CSIC, Apartado 73, E-33080 Oviedo (Spain); Urones-Garrote, E. [Centro Nacional de Microscopia Electronica, Universidad Complutense, E-28040, Madrid (Spain); Avila-Brande, D.; Otero-Diaz, L.C. [Departamento de Quimica Inorganica, Facultad de Ciencias Quimicas, Universidad Complutense, E-28040, Madrid (Spain)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Activated carbons were produced by KOH activation at 700 Degree-Sign C. Black-Right-Pointing-Pointer The observed nanostructure consists of highly disordered graphene-like layers with sp{sup 2} bond content Almost-Equal-To 95%. Black-Right-Pointing-Pointer Textural parameters show high surface area ( Almost-Equal-To 1000 m{sup 2}/g) and pore width of 1.3-1.8 nm. Black-Right-Pointing-Pointer Specific capacitance reaches values as high as 161 F/g. - Abstract: Low cost activated carbons have been produced via chemical activation, by using KOH at 700 Degree-Sign C, from the bamboo species Guadua Angustifolia and Bambusa Vulgaris Striata and the residues from shells of the fruits of Castanea Sativa and Juglans Regia as carbon precursors. The scanning electron microscopy micrographs show the conservation of the precursor shape in the case of the Guadua Angustifolia and Bambusa Vulgaris Striata activated carbons. Transmission electron microscopy analyses reveal that these materials consist of carbon platelet-like particles with variable length and thickness, formed by highly disordered graphene-like layers with sp{sup 2} content Almost-Equal-To 95% and average mass density of 1.65 g/cm{sup 3} (25% below standard graphite). Textural parameters indicate a high porosity development with surface areas ranging from 850 to 1100 m{sup 2}/g and average pore width centered in the supermicropores range (1.3-1.8 nm). The electrochemical performance of the activated carbons shows specific capacitance values at low current density (1 mA/cm{sup 2}) as high as 161 F/g in the Juglans Regia activated carbon, as a result of its textural parameters and the presence of pseudocapacitance derived from surface oxygenated acidic groups (mainly quinones and ethers) identified in this activated carbon.

  19. Carbon-based electrocatalysts for advanced energy conversion and storage

    OpenAIRE

    Zhang, Jintao; Xia, Zhenhai; Dai, Liming

    2015-01-01

    Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) play curial roles in electrochemical energy conversion and storage, including fuel cells and metal-air batteries. Having rich multidimensional nanoarchitectures [for example, zero-dimensional (0D) fullerenes, 1D carbon nanotubes, 2D graphene, and 3D graphite] with tunable electronic and surface characteristics, various carbon nanomaterials have been demonstrated to act as efficient metal-free electrocatalysts for ORR and OER ...

  20. Febrication of Carbon-Nanotube-Forest Based Bolometer

    OpenAIRE

    Wood, Brian; Dyer, J. S.; Thurgood, V. A.; Shen, T. -C.

    2014-01-01

    Due to the nearly-vertical alignment and the band structure of graphite, carbon nanotube forests could have near-unity emissivity which make them ideal candidates as the absorbers for radiometric devices. However, forest height, carbon nanotube density, and the presence of surface defects will affect the total reflectance and transmittance. With optimized growth conditions, a total reflectance of 0.003 and a transmittance of 0.001 has been achieved in the 2 µm - 16 µm spectral region. Fabrica...

  1. Palladium on Nitrogen-Doped Mesoporous Carbon: A Bifunctional Catalyst for Formate-Based, Carbon-Neutral Hydrogen Storage.

    Science.gov (United States)

    Wang, Fanan; Xu, Jinming; Shao, Xianzhao; Su, Xiong; Huang, Yanqiang; Zhang, Tao

    2016-02-01

    The lack of safe, efficient, and economical hydrogen storage technologies is a hindrance to the realization of the hydrogen economy. Reported herein is a reversible formate-based carbon-neutral hydrogen storage system that is established over a novel catalyst comprising palladium nanoparticles supported on nitrogen-doped mesoporous carbon. The support was fabricated by a hard template method and nitridated under a flow of ammonia. Detailed analyses demonstrate that this bicarbonate/formate redox equilibrium is promoted by the cooperative role of the doped nitrogen functionalities and the well-dispersed, electron-enriched palladium nanoparticles. PMID:26763714

  2. Palladium on Nitrogen-Doped Mesoporous Carbon: A Bifunctional Catalyst for Formate-Based, Carbon-Neutral Hydrogen Storage.

    Science.gov (United States)

    Wang, Fanan; Xu, Jinming; Shao, Xianzhao; Su, Xiong; Huang, Yanqiang; Zhang, Tao

    2016-02-01

    The lack of safe, efficient, and economical hydrogen storage technologies is a hindrance to the realization of the hydrogen economy. Reported herein is a reversible formate-based carbon-neutral hydrogen storage system that is established over a novel catalyst comprising palladium nanoparticles supported on nitrogen-doped mesoporous carbon. The support was fabricated by a hard template method and nitridated under a flow of ammonia. Detailed analyses demonstrate that this bicarbonate/formate redox equilibrium is promoted by the cooperative role of the doped nitrogen functionalities and the well-dispersed, electron-enriched palladium nanoparticles.

  3. Adsorptive removal of hydrophobic organic compounds by carbonaceous adsorbents: A comparative study of waste-polymer-based,coal-based activated carbon, and carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    Fei Lian; Chun Chang; Yang Du; Lingyan Zhu; Baoshan Xing; Chang Liu

    2012-01-01

    Adsorption of the hydrophobic organic compounds (HOCs) trichloroethylene (TCE),1,3-dichlorobenzene (DCB),1,3-dinitrobenzene (DNB) and γ-hexachlorocyclohexane (HCH) on five different carbonaceous materials was compared.The adsorbents included three polymer-based activated carbons,one coal-based activated carbon (F400) and multiwalled carbon nanotubes (MWNT).The polymerbased activated carbons were prepared using KOH activation from waste polymers:polyvinyl chloride (PVC),polyethyleneterephthalate (PET) and tire rubber (TR).Compared with F400 and MWNT,activated carbons derived from PVC and PET exhibited fast adsorption kinetics and high adsorption capacity toward the HOCs,attributed to their extremely large hydrophobic surface area (2700 m2/g) and highly mesoporous structures.Adsorption of small-sized TCE was stronger on the tire-rubber-based carbon and F400 resulting from the pore-filling effect.In contrast,due to the molecular sieving effect,their adsorption on HCH was lower.MWNT exhibited the lowest adsorption capacity toward HOCs because of its low surface area and characteristic of aggregating in aqueous solution.

  4. Carbon Based Electrodes Modified with Horseradish Peroxidase Immobilized in Conducting Polymers for Acetaminophen Analysis

    OpenAIRE

    Cecilia Cristea; Robert Sandulescu; Anca Florea; Mihaela Tertis

    2013-01-01

    The development and optimization of new biosensors with horseradish peroxidase immobilized in carbon nanotubes-polyethyleneimine or polypyrrole nanocomposite film at the surface of two types of transducer is described. The amperometric detection of acetaminophen was carried out at −0.2 V versus Ag/AgCl using carbon based-screen printed electrodes (SPEs) and glassy carbon electrodes (GCEs) as transducers. The electroanalytical parameters of the biosensors are highly dependent on their configur...

  5. Influence of electrode preparation on the electrochemical behaviour of carbon-based supercapacitors

    OpenAIRE

    Ruiz Ruiz, Vanesa; Blanco Rodríguez, Clara; Granda Ferreira, Marcos; Menéndez López, Rosa María; Santamaría Ramírez, Ricardo

    2007-01-01

    [EN] This work investigates the influence of electrode preparation on the electrochemical behaviour of carbon-based supercapacitors. Studies were performed using the same activated carbon and polymer polyvynilidene fluoride (PVDF) in the same proportions (10 wt.% PVDF). Only the way in which these components were mixed was modified. The procedure for mixing the activated carbon and the polymer has a significant influence on the electrochemical behaviour of the electrode used in a supercapacit...

  6. Fabrication and Optimization of Carbon Nanomaterial-Based Lithium-Ion Battery Anodes

    OpenAIRE

    Somnhot, Parina

    2012-01-01

    Lithium-ion batteries possess high energy and power densities, making them ideal candidates for energy storage requirements in various military applications. Commercially produced lithium-ion battery anodes are commonly graphitic carbon-based. However, graphitic carbons are limited in surface area and possess slow intercalation kinetics. The energy and power density demands of future technologies require improved lithium-ion battery performance. Carbon nanomaterials, such as carbide-derived c...

  7. Measurement of 5-eV atomic oxygen using carbon-based films: preliminary results

    OpenAIRE

    White, C de B; Roberts, G. T.; Chambers, A.R.

    2005-01-01

    Carbon-based sensors have been developed to measure the atmospheric neutral atomic oxygen (AO) flux experienced by spacecraft in low Earth orbit. Thin- and thick-film carbon sensor elements were deposited onto an alumina substrate between thick-film gold tracks and silver palladium solder pads. AO flux is deduced by measuring resistance changes as the carbon film erodes and applying a simple theory. A wide range of responses were observed that are dependent on the deposition process and post ...

  8. Research Status and Development Trend of Intelligent Prosthetic Knee%假肢智能膝关节的研究现状和发展趋势

    Institute of Scientific and Technical Information of China (English)

    王振平; 喻洪流; 杜妍辰; 曹武警; 胡杰

    2015-01-01

    In recent years,with the increasing number of amputation caused by traffic accidents,natural disasters or cardiovascular diseases,the research on about intelligent prosthetic knee has become a research focus. However,the control of intelligent prosthetic knee with high performance is still the difficulty of research. In this paper,based on the classification of intelligent prosthetic knee,control methods of intelligent knee joint were ana-lyzed,and the future development trend of intelligent prosthetic knee was discussed as well.%近年来,随着交通、工伤事故、自然灾害以及心血管等造成的截肢人数的增多,假肢智能膝关节的研究成为各国研究的热点,而高性能的假肢智能膝关节的控制仍然是研究的难点。本文在对假肢智能膝关节进行分类的基础上,对智能膝关节的测控方法进行了分析,并对假肢智能膝关节未来发展趋势进行展望。

  9. Postoperative transcutaneous oxygen measurement in the prediction of delayed wound healing and prosthetic fitting among amputees during rehabilitation. A pilot study.

    Science.gov (United States)

    Yablon, S A; Novick, E S; Jain, S S; Inhoffer, M; Graves, D E

    1995-01-01

    Postoperative assessment of amputation wound healing remains largely subjective in nature, being based on the physician's clinical judgement. These considerations significantly impact on the rehabilitation course, as premature prosthetic fitting may result in wound breakdown. Alternatively, delayed healing may result in prolonged hospital length of stay. Few attempts have been made to correlate objective parameters of limb perfusion with amputation wound healing or prosthetic fitting outcome during the rehabilitation phase of treatment. A pilot study was conducted, in which the transcutaneous oxygen monitor, a noninvasive device measuring transcutaneous partial pressure of oxygen (tcpO2), was applied to the stumps of 11 consecutive above-or below-knee amputees admitted for rehabilitation after amputation. All patients were tested within 1 wk of admission and 45 days of amputation. The treatment team was blinded as to the test results. A direct correlation was observed between wound healing outcome and tcpO2 results (Fisher's exact test [FET], P = 0.03), and no patient with a tcpO2 of rpbi], = -0.835; P = 0.01), delayed prosthetic fitting (rpbi = 0.742; p = 0.01), and poorer wound healing at admission (rpbi = 0.932; P = 0.001). Postoperative tcpO2 measurement may have use in objectively identifying patients at greater risk of delayed wound healing and prosthetic fitting, although further study is warranted.

  10. Physical and chemical properties of selected agricultural byproduct-based activated carbons and their ability to adsorb geosmin.

    Science.gov (United States)

    Ng, Chilton; Losso, Jack N; Marshall, Wayne E; Rao, Ramu M

    2002-09-01

    The objectives of this study were to evaluate selected physical and chemical properties of agricultural byproduct-based activated carbons made from pecan shells and sugarcane bagasse, and compare those properties to a commercial coal-based activated carbon as well as to compare the adsorption efficiency of these carbons for geosmin. Comparison of the physical and chemical properties of pecan shell- and bagasse-based carbons to the commercial carbon, Calgon Filtrasorb 400, showed that pecan shell carbon, but not the bagasse carbon, compared favorably to Filtrasorb 400, especially in terms of surface area, bulk density, ash and attrition. A carbon dosage study done in a model system showed the amount of geosmin adsorbed to be greater for Filtrasorb 400 and the bagasse-based carbon at low carbon concentrations than for the pecan shell carbons, but geosmin adsorption was similar in all carbons at higher carbon dosages. Application of the Freundlich isotherm model to the adsorption data showed that carbons made by steam activation of pecan shells or sugarcane bagasse had geosmin adsorption characteristics most like those of the commercial carbon. In terms of physical, chemical and adsorptive properties, steam-activated pecan shell carbon most resembled the commercial carbon and has the potential to replace Filtrasorb 400 in applications involving removal of geosmin from aqueous environments.

  11. Xeroderma Pigmentosum with Melanoma of Face and Its Prosthetic Management

    International Nuclear Information System (INIS)

    Xeroderma pigmentosum is a rare genetic disorder, characterized by cutaneous, ocular and neurological symptoms. Squamous cell carcinoma and melanoma are also its secondary characters. This case report is about maxillofacial prosthetic management of a 10 years old child presented with xeroderma pigmentosum. The nose of the patient was excised surgically due to melanoma. This case report elaborates the role of prosthodontist and the whole procedure of constructing the nasal prosthesis via conventional technique by using the patient's sibling nasal form as template. Regular follow up revealed marked improvement in esthetics, function and ultimately patient's quality of life. (author)

  12. Development and marketing of a prosthetic urinary control valve system

    Science.gov (United States)

    Tenney, J. B., Jr.; Rabinowitz, R.; Rogers, D. W.; Harrison, H. N.

    1983-01-01

    An implantable prosthetic for the control of urinary incontinence was developed and marketed. Three phases are presented: bench development studies, animal trials, and human clinical trials. This work was performed under the direction of a Research Team at Rochester General Hospital (RGH). Bench trials were completed on prototype hardware and provided early verification of the device's ability to withstand repeated cyclic testing. Configurational variants were evaluated and a preferred design concept was established. Silicone rubber (medical grade) was selected as the preferred material for the prosthesis.

  13. Artifact reduction strategies for prosthetic heart valve CT imaging

    OpenAIRE

    Habets, Jesse; Symersky, Petr; Leiner, Tim; de Mol, Bas A. J. M.; Willem P Th M Mali; Budde, Ricardo P.J.

    2012-01-01

    Multislice CT evaluation of prosthetic heart valves (PHV) is limited by PHV-related artifacts. We assessed the influence of different kV settings, a metal artifact reduction filter (MARF) and an iterative reconstruction algorithm (IR) on PHV-induced artifacts in an in vitro model. A Medtronic-Hall tilting disc and St Jude bileafet PHV were imaged using a 64-slice scanner with 100 kV/165 mAs, 120 kV/100 mAs, 140 kV/67 mAs at an equal CTDIvol. Images were reconstructed with (1) filtered back pr...

  14. Reconstruction of Exenterated Orbit using Combined Surgical and Prosthetic Approach.

    Science.gov (United States)

    Prithviraj, D R; Gupta, Anish; Khare, Sumit; Garg, Pooja; Pujari, Malesh

    2011-05-01

    Reconstruction of an exenterated orbit remains a challenge. Orbital prostheses are nowadays are made of silicone elastomers. A major limitation with silicone orbital prostheses is their relatively short life span. This case report describes the treatment of a patient with an exenterated orbit using a combined surgical and prosthetic approach. The upper and lower eyelids were reconstructed surgically using a deltopectoral flap. A sectional eye prosthesis was made and placed in the modified bottle-neck shaped defect to restore the patient's appearance and confidence. PMID:21969903

  15. Prosthetic rehabilitation of a patient with facial mucormycosis

    Directory of Open Access Journals (Sweden)

    Digvijay Sanjay Deshpande

    2014-01-01

    Full Text Available Facial mucormycosis is a known complication in patients with immunological or metabolic compromise. Mainstay of treatment includes reversal of the compromised state, systemic antifungals and repeated radical debridements. The resultant deformity following debridement causes gross morbidity and psycho-social embarrassment. Surgical reconstruction is difficult on account of co-morbid diseases. Nonsurgical prosthetic rehabilitation gives fairly accurate correction in these patients. We report a case of a 62-year-old male diabetic with facial mucormycosis where debridement resulted in a gross morbid defect. However, effective rehabilitation was achieved using extraoral prosthesis.

  16. Mobile Carbon Monoxide Monitoring System Based on Arduino-Matlab for Environmental Monitoring Application

    Science.gov (United States)

    Azieda Mohd Bakri, Nur; Junid, Syed Abdul Mutalib Al; Razak, Abdul Hadi Abdul; Idros, Mohd Faizul Md; Karimi Halim, Abdul

    2015-11-01

    Nowadays, the increasing level of carbon monoxide globally has become a serious environmental issue which has been highlighted in most of the country globally. The monitoring of carbon monoxide content is one of the approaches to identify the level of carbon monoxide pollution towards providing the solution for control the level of carbon monoxide produced. Thus, this paper proposed a mobile carbon monoxide monitoring system for measuring the carbon monoxide content based on Arduino-Matlab General User Interface (GUI). The objective of this project is to design, develop and implement the real-time mobile carbon monoxide sensor system and interfacing for measuring the level of carbon monoxide contamination in real environment. Four phases or stages of work have been carried out for the accomplishment of the project, which classified as sensor development, controlling and integrating sensor, data collection and data analysis. As a result, a complete design and developed system has been verified with the handheld industrial standard carbon monoxide sensor for calibrating the sensor sensitivity and measurement in the laboratory. Moreover, the system has been tested in real environments by measuring the level of carbon monoxide in three different lands used location; industrial area; residential area and main road (commercial area). In this real environment test, the industrial area recorded the highest reading with 71.23 ppm and 82.59 ppm for sensor 1 and sensor 2 respectively. As a conclusion, the mobile realtime carbon monoxide system based on the Arduino-Matlab is the best approach to measure the carbon monoxide concentration in different land-used since it does not require a manual data collection and reduce the complexity of the existing carbon monoxide level concentration measurement practise at the same time with a complete data analysis facilities.

  17. Accountable Accounting: Carbon-Based Management on Marginal Lands

    Directory of Open Access Journals (Sweden)

    Tara L. DiRocco

    2014-04-01

    Full Text Available Substantial discussion exists concerning the best land use options for mitigating greenhouse gas (GHG emissions on marginal land. Emissions-mitigating land use options include displacement of fossil fuels via biofuel production and afforestation. Comparing C recovery dynamics under these different options is crucial to assessing the efficacy of offset programs. In this paper, we focus on forest recovery on marginal land, and show that there is substantial inaccuracy and discrepancy in the literature concerning carbon accumulation. We find that uncertainty in carbon accumulation occurs in estimations of carbon stocks and models of carbon dynamics over time. We suggest that analyses to date have been largely unsuccessful at determining reliable trends in site recovery due to broad land use categories, a failure to consider the effect of current and post-restoration management, and problems with meta-analysis. Understanding of C recovery could be greatly improved with increased data collection on pre-restoration site quality, prior land use history, and management practices as well as increased methodological standardization. Finally, given the current and likely future uncertainty in C dynamics, we recommend carbon mitigation potential should not be the only environmental service driving land use decisions on marginal lands.

  18. Low carbon spaces : area-based carbon emission reduction : a scoping study

    OpenAIRE

    Tyndall Centre for Climate Change Research; Sustainable Development Commission

    2002-01-01

    The SDC appointed a team led by the Tyndall Centre for Climate Change Research to review existing experiences on 'carbon reduction' at the sub-UK scale and to draw out lessons and recommendations. Prepared for the Sustainable Development Commission by the Tyndall Centre for Climate Change Research. Publisher PDF

  19. Cropland Carbon Fluxes in the United States: Increasing Geospatial Resolution of Inventory-based Carbon Accounting

    Science.gov (United States)

    Net annual soil carbon change, fossil fuel emissions from cropland production, and cropland net primary productivity were estimated and spatially distributed using land cover defined by the Moderate Resolution Imaging Spectroradiometer (MODIS) and by the Cropland Data Layer (CDL). Spatially resolved...

  20. Ceramics in Restorative and Prosthetic DENTISTRY1

    Science.gov (United States)

    Kelly, J. Robert

    1997-08-01

    This review is intended to provide the ceramic engineer with information about the history and current use of ceramics in dentistry, contemporary research topics, and potential research agenda. Background material includes intra-oral design considerations, descriptions of ceramic dental components, and the origin, composition, and microstructure of current dental ceramics. Attention is paid to efforts involving net-shape processing, machining as a forming method, and the analysis of clinical failure. A rationale is presented for the further development of all-ceramic restorative systems. Current research topics receiving attention include microstructure/processing/property relationships, clinical failure mechanisms and in vitro testing, wear damage and wear testing, surface treatments, and microstructural modifications. The status of the field is critically reviewed with an eye toward future work. Significant improvements seem possible in the clinical use of ceramics based on engineering solutions derived from the study of clinically failed restorations, on the incorporation of higher levels of "biomimicry" in new systems, and on the synergistic developments in dental cements and adhesive dentin bonding.

  1. The Concept and Theoretical Implications of Carbon Emissions Rights Based on Individual Equity%The Concept and Theoretical Implications of Carbon Emissions Rights Based on Individual Equity

    Institute of Scientific and Technical Information of China (English)

    Pan Jiahua; Zheng Yan

    2011-01-01

    Climate change has become a hot topic in international environmental negotiations. For post-Kyoto international climate regime negotiations, many countries have proposed a variety of frameworks to share the emission reduction responsibilities and allocate carbon emission rights, and have tried to quantify the emission reduction obligations of all countries based on the perspectives of international equity and individual equity. In this paper, the authors have distinguished the concepts of carbon emissions rights based on these two perspectives respectively, have analyzed the relationship between carbon emissions per capita and economic development, and have calculated and compared the proportion of cumulative emissions per capita of different countries in history and future, and then authors conclude that emission reduction obligations should be allocated based on each country's conditions, including historical emissions, development stage, and future demands. Developed countries should take the initiative to significantly reduce their emissions because they have already accomplished their industrialization process. However, developing countries are still in the process of industrialization, which requires more emission rights to meet their development needs. For China, the concept of carbon emissions based on individual equity can be used as a theoretical tool for the allocating the international carbon emissions rights.

  2. Carbon-Dot-Based Nanosensors for the Detection of Intracellular Redox State.

    Science.gov (United States)

    Liu, Ye; Tian, Ye; Tian, Yefei; Wang, Yajun; Yang, Wuli

    2015-11-25

    Carbon-dot-based nanosensors are prepared through sequentially assembling a polymer/carbon dot multilayer shell on mesoporous silica nanoparticles with different crosslinking densities of disulfide bonds; they can be utilized to evaluate the gluthathione (GSH) concentration. In vitro cell assays demonstrate the feasibility of using such nanosensors in evaluating the intracellular redox state of different cells. PMID:26450796

  3. Copper-decorated carbon nanotubes-based composite electrodes for nonenzymatic detection of glucose

    OpenAIRE

    Pop, A.(National Institute for Physics and Nuclear Engineering, Bucharest, Romania); Manea, F.; Orha, C.; Motoc, S.; Llinoiu, E.; Vaszilcsin, N.; Schoonman, J.

    2012-01-01

    The aim of this study was to prepare three types of multiwall carbon nanotubes (CNT)-based composite electrodes and to modify their surface by copper electrodeposition for nonenzymatic oxidation and determination of glucose from aqueous solution. Copper-decorated multiwall carbon nanotubes composite electrode (Cu/CNT-epoxy) exhibited the highest sensitivity to glucose determination.

  4. Copper-decorated carbon nanotubes-based composite electrodes for nonenzymatic detection of glucose

    NARCIS (Netherlands)

    Pop, A.; Manea, F.; Orha, C.; Motoc, S.; Llinoiu, E.; Vaszilcsin, N.; Schoonman, J.

    2012-01-01

    The aim of this study was to prepare three types of multiwall carbon nanotubes (CNT)-based composite electrodes and to modify their surface by copper electrodeposition for nonenzymatic oxidation and determination of glucose from aqueous solution. Copper-decorated multiwall carbon nanotubes composite

  5. Development of effective nanobiocatalytic systems through the immobilization of hydrolases on functionalized carbon-based nanomaterials

    NARCIS (Netherlands)

    Pavlidis, Ioannis V.; Vorhaben, Torge; Tsoufis, Theodoros; Rudolf, Petra; Bornscheuer, Uwe T.; Gournis, Dimitrios; Stamatis, Haralambos

    2012-01-01

    In this study we report the use of functionalized carbon-based nanomaterials, such as amine-functionalized graphene oxide (GO) and multi-walled carbon nanotubes (CNTs), as effective immobilization supports for various lipases and esterases of industrial interest. Structural and biochemical character

  6. A mechanism to compensate undesired stiffness in joints of prosthetic hands

    NARCIS (Netherlands)

    Smit, G.; Plettenbrug, D.H.; Van der Helm, F.C.T.

    2014-01-01

    Background: Cosmetic gloves that cover a prosthetic hand have a parasitic positive stiffness that counteracts the flexion of a finger joint. Objectives: Reducing the required input torque to move a finger of a prosthetic hand by compensating the parasitic stiffness of the cosmetic glove. Study des

  7. Prosthetic joint infection due to Lysobacter thermophilus diagnosed by 16S rRNA gene sequencing.

    Science.gov (United States)

    Dhawan, B; Sebastian, S; Malhotra, R; Kapil, A; Gautam, D

    2016-01-01

    We report the first case of prosthetic joint infection caused by Lysobacter thermophilus which was identified by 16S rRNA gene sequencing. Removal of prosthesis followed by antibiotic treatment resulted in good clinical outcome. This case illustrates the use of molecular diagnostics to detect uncommon organisms in suspected prosthetic infections.

  8. Shape sensing for computer aided below-knee prosthetic socket design.

    Science.gov (United States)

    Fernie, G R; Griggs, G; Bartlett, S; Lunau, K

    1985-04-01

    Shape sensing is useful in the computer aided prosthetic fitting process for two purposes. 1. To input characteristic prosthetic shapes that have been developed over the years through the experience of prosthetists. 2. To provide an accurate and rapid measurement of the anatomical shape of the stump. This paper describes two instruments which have been built to meet these objectives.

  9. Prosthetic fitting, use, and satisfaction following lower-limb amputation: A prospective study

    Directory of Open Access Journals (Sweden)

    Joseph B. Webster, MD

    2013-01-01

    Full Text Available Providing a satisfactory, functional prosthesis following lower-limb amputation is a primary goal of rehabilitation. The objectives of this study were to describe the rate of successful prosthetic fitting over a 12 mo period; describe prosthetic use after amputation; and determine factors associated with greater prosthetic fitting, function, and satisfaction. The study design was a multicenter prospective cohort study of individuals undergoing their first major lower-limb amputation because of vascular disease and/or diabetes. At 4 mo, unsuccessful prosthetic fitting was significantly associated with depression, prior arterial reconstruction, diabetes, and pain in the residual limb. At 12 mo, 92% of all subjects were fit with a prosthetic limb and individuals with transfemoral amputation were significantly less likely to have a prosthesis fit. Age older than 55 yr, diagnosis of a major depressive episode, and history of renal dialysis were associated with fewer hours of prosthetic walking. Subjects who were older, had experienced a major depressive episode, and/or were diagnosed with chronic obstructive pulmonary disease had greater functional restriction. Thus, while most individuals achieve successful prosthetic fitting by 1 yr following a first major nontraumatic lower-limb amputation, a number of medical variables and psychosocial factors are associated with prosthetic fitting, utilization, and function.

  10. Brown-Pigmented Mycobacterium mageritense as a Cause of Prosthetic Valve Endocarditis and Bloodstream Infection.

    Science.gov (United States)

    McMullen, Allison R; Mattar, Caline; Kirmani, Nigar; Burnham, Carey-Ann D

    2015-08-01

    Mycobacterium spp. are a rare cause of endocarditis. Herein, we describe a case of Mycobacterium mageritense prosthetic valve endocarditis. This organism produced an unusual brown pigment on solid media. Cultures of valve tissue for acid-fast bacilli might be considered in some cases of apparently culture-negative prosthetic valve endocarditis.

  11. Fabrication and electrochemical behavior of single-walled carbon nanotube/graphite-based electrode

    Energy Technology Data Exchange (ETDEWEB)

    Moghaddam, Abdolmajid Bayandori [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran P.O. Box 14155-6455, Tehran (Iran, Islamic Republic of); Medical Nanotechnology Research Centre, Medical Sciences/University of Tehran, P.O. Box 14155-6451, Tehran (Iran, Islamic Republic of); Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran P.O. Box 14155-6455, Tehran (Iran, Islamic Republic of)], E-mail: Ganjali@khayam.ut.ac.ir; Dinarvand, Rassoul [Medical Nanotechnology Research Centre, Medical Sciences/University of Tehran, P.O. Box 14155-6451, Tehran (Iran, Islamic Republic of); Razavi, Taherehsadat [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran P.O. Box 14155-6455, Tehran (Iran, Islamic Republic of); Riahi, Siavash [Institute of Petroleum Engineering, Faculty of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Rezaei-Zarchi, Saeed [Department of Biology, Payam-e-Noor University, Yazd (Iran, Islamic Republic of); Norouzi, Parviz [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran P.O. Box 14155-6455, Tehran (Iran, Islamic Republic of)

    2009-01-01

    An electrochemical method for determining the dihydroxybenzene derivatives on glassy carbon (GC) has been developed. In this method, the performance of a single-walled carbon nanotube (SWCNT)/graphite-based electrode, prepared by mixing SWCNTs and graphite powder, was described. The resulting electrode shows an excellent behavior for redox of 3,4-dihydroxybenzoic acid (DBA). SWCNT/graphite-based electrode presents a significant decrease in the overvoltage for DBA oxidation as well as a dramatic improvement in the reversibility of DBA redox behavior in comparison with graphite-based and glassy carbon (GC) electrodes. In addition, scanning electron microscopy (SEM) and atomic force microscopy (AFM) procedures performed for used SWCNTs.

  12. Preparation and Morphological Study of Coal-tar-based Carbon Foam

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-ying; ZHU Jiang-jiang; ZHANG Chang-xing; WANG Yi-min; WANG Yan-ping; YU Ming-fang

    2006-01-01

    A novel process for fabricating coal-tar pitch derived carbon foam was introduced. The coal-tar based mesophase pitch was characterized by Infrared Spectrum and Wide Angle X-ray Diffraction. Scanning Electron Microscope was used for the morphological study of carbon foam. The results showed that the pitch foam with pores of 300 - 500 μm and low density of 0.2 - 0.5 g/cm-3 could be successfully fabricated and further carbonized and graphtized to obtain a novel carbon foam.

  13. Septic arthritis caused by Mycobacterium fortuitum and Mycobacterium abscessus in a prosthetic knee joint: case report and review of literature.

    Science.gov (United States)

    Wang, Shu-Xiang; Yang, Chang-Jen; Chen, Yu-Chuan; Lay, Chorng-Jang; Tsai, Chen-Chi

    2011-01-01

    Nontuberculous mycobacterium (NTM) is an infrequent cause of prosthetic knee joint infections. Simultaneous infection with different NTM species in a prosthetic knee joint has not been previously reported. A case of prosthetic knee joint infection caused by Mycobacterium abscessus and M. fortuitum is described in this report. The patient was successfully treated with adequate antibiotics and surgery. The clinical features of sixteen previously reported cases of prosthetic knee joint infection caused by NTM are reviewed.

  14. Carbon Nanotube Film-Based Speaker Developed in Tsinghua University

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ A research group from Tsinghua University led by Prof.Fan Shoushan,Member of the Chinese Academy of Sciences,and Jiang Kaili,associate professor of Physics,found that carbon nanotube thin film could act as a speaker once fed by audio frequency electric currents.These carbon nanotube loudspeakers are only tens of a nanometer thick,transparent,flexible and stretchable,which can be further tailored into any shape and size.These results have been published in the journal Nano Letter.

  15. Enhancing anaerobic digestion of complex organic waste with carbon-based conductive materials.

    Science.gov (United States)

    Dang, Yan; Holmes, Dawn E; Zhao, Zhiqiang; Woodard, Trevor L; Zhang, Yaobin; Sun, Dezhi; Wang, Li-Ying; Nevin, Kelly P; Lovley, Derek R

    2016-11-01

    The aim of this work was to study the methanogenic metabolism of dog food, a food waste surrogate, in laboratory-scale reactors with different carbon-based conductive materials. Carbon cloth, carbon felt, and granular activated carbon all permitted higher organic loading rates and promoted faster recovery of soured reactors than the control reactors. Microbial community analysis revealed that specific and substantial enrichments of Sporanaerobacter and Methanosarcina were present on the carbon cloth surface. These results, and the known ability of Sporanaerobacter species to transfer electrons to elemental sulfur, suggest that Sporanaerobacter species can participate in direct interspecies electron transfer with Methanosarcina species when carbon cloth is available as an electron transfer mediator. PMID:27611035

  16. Research of fiber carbon dioxide sensing system based laser absorption spectrum

    Science.gov (United States)

    Wei, Yubin; Zhang, Tingting; Li, Yanfang; Zhao, Yanjie; Wang, Chang; Liu, Tongyu

    2012-02-01

    Carbon dioxide is one of the important gas need to be detected in coal mine safety. In the mine limited ventilation environment, Concentration of carbon dioxide directly affects the health of coal miners. Carbon dioxide is also one of important signature Gas in spontaneous combustion forecasting of coal goaf area, it is important to accurately detect concentration of carbon dioxide in coal goaf area. This paper proposed a fiber carbon dioxide online sensing system based on tunable diode laser spectroscopy. The system used laser absorption spectroscopy and optical fiber sensors combined, and a near-infrared wavelength 1608nm fiber-coupled distributed feedback laser (DFB) as a light source and a 7cm length gas cell, to achieve a high sensitivity concentration detection of carbon dioxide gas. The technical specifications of sensing system can basically meet the need of mine safety.

  17. The effect of gamma ray irradiation on PAN-based intermediate modulus carbon fibers

    International Nuclear Information System (INIS)

    Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) were conducted on PAN-based intermediate modulus carbon fibers to investigate the structure and surface hydrophilicity of the carbon fibers before and after gamma irradiation. Two methods were used to determine Young’s modulus of the carbon fibers. The results show that gamma ray irradiation improved the degree of graphitization and introduced compressive stress into carbon fiber surface. Gamma ray also improved the carbon fiber surface hydrophilicity through increasing the value of O/C and enhancing the quantity of oxygen functional groups on carbon fibers. No distinct morphology change was observed after gamma ray irradiation. The Young’s modulus of the fibers increased with increasing irradiation dose

  18. The effect of gamma ray irradiation on PAN-based intermediate modulus carbon fibers

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bin [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Feng, Yi, E-mail: fyhfut@163.com [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Qian, Gang; Zhang, Jingcheng [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Zhuang, Zhong; Wang, Xianping [Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2013-11-15

    Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) were conducted on PAN-based intermediate modulus carbon fibers to investigate the structure and surface hydrophilicity of the carbon fibers before and after gamma irradiation. Two methods were used to determine Young’s modulus of the carbon fibers. The results show that gamma ray irradiation improved the degree of graphitization and introduced compressive stress into carbon fiber surface. Gamma ray also improved the carbon fiber surface hydrophilicity through increasing the value of O/C and enhancing the quantity of oxygen functional groups on carbon fibers. No distinct morphology change was observed after gamma ray irradiation. The Young’s modulus of the fibers increased with increasing irradiation dose.

  19. Mechanical design and performance specifications of anthropomorphic prosthetic hands: A review

    Directory of Open Access Journals (Sweden)

    Joseph T. Belter, MS, BS

    2013-08-01

    Full Text Available In this article, we set forth a detailed analysis of the mechanical characteristics of anthropomorphic prosthetic hands. We report on an empirical study concerning the performance of several commercially available myoelectric prosthetic hands, including the Vincent, iLimb, iLimb Pulse, Bebionic, Bebionic v2, and Michelangelo hands. We investigated the finger design and kinematics, mechanical joint coupling, and actuation methods of these commercial prosthetic hands. The empirical findings are supplemented with a compilation of published data on both commercial and prototype research prosthetic hands. We discuss numerous mechanical design parameters by referencing examples in the literature. Crucial design trade-offs are highlighted, including number of actuators and hand complexity, hand weight, and grasp force. Finally, we offer a set of rules of thumb regarding the mechanical design of anthropomorphic prosthetic hands.

  20. Mechanical design and performance specifications of anthropomorphic prosthetic hands: a review.

    Science.gov (United States)

    Belter, Joseph T; Segil, Jacob L; Dollar, Aaron M; Weir, Richard F

    2013-01-01

    In this article, we set forth a detailed analysis of the mechanical characteristics of anthropomorphic prosthetic hands. We report on an empirical study concerning the performance of several commercially available myoelectric prosthetic hands, including the Vincent, iLimb, iLimb Pulse, Bebionic, Bebionic v2, and Michelangelo hands. We investigated the finger design and kinematics, mechanical joint coupling, and actuation methods of these commercial prosthetic hands. The empirical findings are supplemented with a compilation of published data on both commercial and prototype research prosthetic hands. We discuss numerous mechanical design parameters by referencing examples in the literature. Crucial design trade-offs are highlighted, including number of actuators and hand complexity, hand weight, and grasp force. Finally, we offer a set of rules of thumb regarding the mechanical design of anthropomorphic prosthetic hands.

  1. TESTS METALLIC BIOMATERIALS FOR COMPUTER-AIDED DESIGN AND MANUFACTURING OF FIXED PROSTHETIC RESTORATIONS

    Directory of Open Access Journals (Sweden)

    Anna M. RYNIEWICZ

    2014-03-01

    Full Text Available A direct metal laser sintering method (DMLS is a new technology used for getting structures by the CAD/CAM procedures. The aim of the elaboration was a question of structural identification and setting strength parameters of titanium (Ticp and its alloy (Ti6Al4V which are used to serve as base for those permanent prosthetic supplements which are later manufactured with the employment of CAD/CAM systems. The research work was performed on Ticp samples – those which were intended for manufacture of structures by decrement milling working, and Ti6Al4V samples that comes from laser increment sintering of powder. According to the results obtained, the following conclusion has been derived: when strength aspect is discussed, the DMLS method is a preferred one for manufacturing of load structures in dentistry and may be an alternate way for the CAD/CAM system used in decrement processing.

  2. A systematic literature review of the effect of different prosthetic components on human functioning with a lower-limb prosthesis

    NARCIS (Netherlands)

    van der Linde, H; Hofstad, CJ; Postema, K; Geertzen, JHB

    2004-01-01

    A correct prosthetic prescription can be derived from adapting the functional benefits of a prosthesis to the functional needs of the prosthetic user. For adequate matching, the functional abilities of the amputees are of value, as well as the technical and functional aspects of the various prosthet

  3. Outdoor dynamic subject-specific evaluation of internal stresses in the residual limb: hydraulic energy-stored prosthetic foot compared to conventional energy-stored prosthetic feet.

    Science.gov (United States)

    Portnoy, Sigal; Kristal, Anat; Gefen, Amit; Siev-Ner, Itzhak

    2012-01-01

    The prosthetic foot plays an important role in propelling, breaking, balancing and supporting body loads while the amputee ambulates on different grounds. It is therefore important to quantify the effect of the prosthetic foot mechanism on biomechanical parameters, in order to prevent pressure ulcers and deep tissue injury. Our aim was to monitor the internal stresses in the residuum of transtibial amputation (TTA) prosthetic-users ambulating on different terrains, which the amputees encounter during their daily activities, i.e. paved floor, grass, ascending and descending stairs and slope. We specifically aimed to compare between the internal stresses in the TTA residuum of amputees ambulating with a novel hydraulic prosthetic foot compared to conventional energy storage and return (ESR) prosthetic feet. Monitoring of internal stresses was accomplished using a portable subject-specific real-time internal stress monitor. We found significant decrease (phydraulic foot, compared to walking with ESR feet. The loading rate calculated while ambulating with the hydraulic foot was at least three times lower than the loading rate calculated while ambulating with the ESR foot. Although the average decrease in internal stresses was ≈ 2-fold larger when replacing single-toe ESR feet with the hydraulic foot than when replacing split-toed ESR feet with the hydraulic foot, the differences were statistically insignificant. Our findings suggest that using a hydraulic prosthetic foot may protect the distal tibial end of the TTA residuum from high stresses, therefore preventing pressure-related injury and pain.

  4. Autotrophic carbon budget in coral tissue: a new 13C-based model of photosynthate translocation.

    Science.gov (United States)

    Tremblay, Pascale; Grover, Renaud; Maguer, Jean François; Legendre, Louis; Ferrier-Pagès, Christine

    2012-04-15

    Corals live in symbiosis with dinoflagellates of the genus Symbiodinum. These dinoflagellates translocate a large part of the photosynthetically fixed carbon to the host, which in turn uses it for its own needs. Assessing the carbon budget in coral tissue is a central question in reef studies that still vexes ecophysiologists. The amount of carbon fixed by the symbiotic association can be determined by measuring the rate of photosynthesis, but the amount of carbon translocated by the symbionts to the host and the fate of this carbon are more difficult to assess. In the present study, we propose a novel approach to calculate the budget of autotrophic carbon in the tissue of scleractinian corals, based on a new model and measurements made with the stable isotope (13)C. Colonies of the scleractinian coral Stylophora pistillata were incubated in H(13)CO (-)(3)-enriched seawater, after which the fate of (13)C was followed in the symbionts, the coral tissue and the released particulate organic carbon (i.e. mucus). Results obtained showed that after 15 min, ca. 60% of the carbon fixed was already translocated to the host, and after 48 h, this value reached 78%. However, ca. 48% of the photosynthetically fixed carbon was respired by the symbiotic association, and 28% was released as dissolved organic carbon. This is different from other coral species, where coral tissue after 48 h. Results show that our (13)C-based model could successfully trace the carbon flow from the symbionts to the host, and the photosynthetically acquired carbon lost from the symbiotic association. PMID:22442377

  5. Prosthetic leg powered by MR brake and SMA wires

    Science.gov (United States)

    Nguyen, The; Munguia, Vicente; Calderon, Jose

    2014-04-01

    Current knee designs for prosthetic legs rely on electric motors for both moving and stationary states. The electric motors draw an especially high level of current to sustain a fixed position. The advantage of using magnetorheological (MR) fluid is that it requires less current and can have a variable braking torque. Besides, the proposed prosthetic leg is actuated by NiTinol wire, a popular shape memory alloy (SMA). The incorporation of NiTinol gives the leg more realistic weight distribution with appropriate arrangement of the batteries and wires. The prosthesis in this research was designed with MR brake as stopping component and SMA wire network as actuating component at the knee. The MR brake was designed with novel non-circular shape for the rotor that improved the braking torque while minimizing the power consumption. The design also helped simplify the control of braking process. The SMA wire network was design so that the knee motion was actively rotated in both directions. The SMA wires were arranged and played very similar role as the leg's muscles. The study started with the overall solid design of the knee including both MR and SMA parts. Theoretical models were derived and programmed in Simulink for both components. The simulation was capable of predicting the power required for moving the leg or hold it in a fixed position for a certain amount of time. Subsequently, the design was prototyped and tested to validate the theoretical prediction. The theoretical models were updated accordingly to correlate with the experimental data.

  6. Classifying prosthetic use via accelerometry in persons with transtibial amputations

    Directory of Open Access Journals (Sweden)

    Morgan T. Redfield, MSEE

    2013-12-01

    Full Text Available Knowledge of how persons with amputation use their prostheses and how this use changes over time may facilitate effective rehabilitation practices and enhance understanding of prosthesis functionality. Perpetual monitoring and classification of prosthesis use may also increase the health and quality of life for prosthetic users. Existing monitoring and classification systems are often limited in that they require the subject to manipulate the sensor (e.g., attach, remove, or reset a sensor, record data over relatively short time periods, and/or classify a limited number of activities and body postures of interest. In this study, a commercially available three-axis accelerometer (ActiLife ActiGraph GT3X+ was used to characterize the activities and body postures of individuals with transtibial amputation. Accelerometers were mounted on prosthetic pylons of 10 persons with transtibial amputation as they performed a preset routine of actions. Accelerometer data was postprocessed using a binary decision tree to identify when the prosthesis was being worn and to classify periods of use as movement (i.e., leg motion such as walking or stair climbing, standing (i.e., standing upright with limited leg motion, or sitting (i.e., seated with limited leg motion. Classifications were compared to visual observation by study researchers. The classifier achieved a mean +/– standard deviation accuracy of 96.6% +/– 3.0%.

  7. Classifying prosthetic use via accelerometry in persons with transtibial amputations.

    Science.gov (United States)

    Redfield, Morgan T; Cagle, John C; Hafner, Brian J; Sanders, Joan E

    2013-01-01

    Knowledge of how persons with amputation use their prostheses and how this use changes over time may facilitate effective rehabilitation practices and enhance understanding of prosthesis functionality. Perpetual monitoring and classification of prosthesis use may also increase the health and quality of life for prosthetic users. Existing monitoring and classification systems are often limited in that they require the subject to manipulate the sensor (e.g., attach, remove, or reset a sensor), record data over relatively short time periods, and/or classify a limited number of activities and body postures of interest. In this study, a commercially available three-axis accelerometer (ActiLife ActiGraph GT3X+) was used to characterize the activities and body postures of individuals with transtibial amputation. Accelerometers were mounted on prosthetic pylons of 10 persons with transtibial amputation as they performed a preset routine of actions. Accelerometer data was postprocessed using a binary decision tree to identify when the prosthesis was being worn and to classify periods of use as movement (i.e., leg motion such as walking or stair climbing), standing (i.e., standing upright with limited leg motion), or sitting (i.e., seated with limited leg motion). Classifications were compared to visual observation by study researchers. The classifier achieved a mean +/- standard deviation accuracy of 96.6% +/- 3.0%.

  8. Dynamic interface pressure distributions of two transtibial prosthetic socket concepts.

    Science.gov (United States)

    Dumbleton, Tim; Buis, Arjan W P; McFadyen, Angus; McHugh, Brendan F; McKay, Geoff; Murray, Kevin D; Sexton, Sandra

    2009-01-01

    In this study, we investigated and compared the dynamic interface pressure distribution of hands-off and hands-on transtibial prosthetic systems by means of pressure mapping. Of the 48 established unilateral amputees recruited, half (n = 24) had been wearing pressure-cast prostheses (IceCast Compact) and the other half (n = 24) had been wearing hand-cast sockets of the patellar tendon bearing design. We measured the dynamic pressure profile of more than 90% of the area within each prosthetic socket by means of four Tekscan F-Scan socket transducer arrays. We compared the interface pressure between socket concepts. We found that the distribution of dynamic pressure at the limb-socket interface was similar for the two intervention (socket prescription) groups. However, a significant difference was found in the magnitude of the interface pressure between the two socket concepts; the interface pressures recorded in the hands-off sockets were higher than those seen in the hands-on concept. Despite the differences in interface pressure, the level of satisfaction with the sockets was similar between subject groups. The sockets instrumented for this study had been in daily use for at least 6 months, with no residual-limb health problems.

  9. Consumer satisfaction with the services of prosthetics and orthotics facilities.

    Science.gov (United States)

    Bosmans, Joline; Geertzen, Jan; Dijkstra, Pieter U

    2009-03-01

    Consumer satisfaction with the services provided in a prosthetics and orthotics (P&O) facility has seldom been studied. The aim of this study was to analyze consumer satisfaction regarding the services provided by 15 P&O facilities in The Netherlands. Consumers (n = 1,364) of these P&O facilities who were fitted with a prosthesis, orthopaedic shoes, an orthosis, or another device, were asked to rate the overall services provided and whether they were satisfied with the device provided and its delivery time. Additionally, they filled in a modified SERVQUAL questionnaire (see Appendix). Consumers gave the service provided by P&O facilities a mean overall rating of 8.1. The highest ratings were given by consumers fitted with a prosthesis (mean overall rating of services: 8.4). In total, 78% of the consumers were satisfied with the device provided and 93% with the delivery time. The results of our study showed that, on the SERVQUAL, 50% of the statements fulfilled the criteria for a satisfactory quality of the services. The overall consumer rating of the service provided by P&O facilities is high and depends on the device provided. The outcomes on the SERVQUAL were moderate. In future, it is important to study consumer satisfaction more extensively in order to improve the quality of P&O services in daily practice. Additionally, specific questionnaires need to be developed to measure all aspects of prosthetic and orthotic care, with the aim to improve the services. PMID:19235068

  10. Quantifying prosthetic gait deviation using simple outcome measures

    Science.gov (United States)

    Kark, Lauren; Odell, Ross; McIntosh, Andrew S; Simmons, Anne

    2016-01-01

    AIM: To develop a subset of simple outcome measures to quantify prosthetic gait deviation without needing three-dimensional gait analysis (3DGA). METHODS: Eight unilateral, transfemoral amputees and 12 unilateral, transtibial amputees were recruited. Twenty-eight able-bodied controls were recruited. All participants underwent 3DGA, the timed-up-and-go test and the six-minute walk test (6MWT). The lower-limb amputees also completed the Prosthesis Evaluation Questionnaire. Results from 3DGA were summarised using the gait deviation index (GDI), which was subsequently regressed, using stepwise regression, against the other measures. RESULTS: Step-length (SL), self-selected walking speed (SSWS) and the distance walked during the 6MWT (6MWD) were significantly correlated with GDI. The 6MWD was the strongest, single predictor of the GDI, followed by SL and SSWS. The predictive ability of the regression equations were improved following inclusion of self-report data related to mobility and prosthetic utility. CONCLUSION: This study offers a practicable alternative to quantifying kinematic deviation without the need to conduct complete 3DGA. PMID:27335814

  11. Polyurethane Foam-Based Ultramicroporous Carbons for CO2 Capture.

    Science.gov (United States)

    Ge, Chao; Song, Jian; Qin, Zhangfeng; Wang, Jianguo; Fan, Weibin

    2016-07-27

    A series of sustainable porous carbon materials were prepared from waste polyurethane foam and investigated for capture of CO2. The effects of preparation conditions, such as precarbonization, KOH to carbon precursor weight ratio, and activation temperature, on the porous structure and CO2 adsorption properties were studied for the purpose of controlling pore sizes and nitrogen content and developing high-performance materials for capture of CO2. The sample prepared at optimum conditions shows CO2 adsorption capacities of 6.67 and 4.33 mmol·g(-1) at 0 and 25 °C under 1 bar, respectively, which are comparable to those of the best reported porous carbons prepared from waste materials. The HCl treatment experiment reveals that about 80% of CO2 adsorption capacity arises from physical adsorption, while the other 20% is due to the chemical adsorption originated from the interaction of basic N groups and CO2 molecules. The relationship between CO2 uptake and pore size at different temperatures indicates that the micropores with pore size smaller than 0.86 and 0.70 nm play a dominant role in the CO2 adsorption at 0 and 25 °C, respectively. It was found that the obtained carbon materials exhibited high recyclability and high selectivity to adsorption of CO2 from the CO2 and N2 mixture. PMID:27376177

  12. Feasibility study of algae-based Carbon Dioxide capture

    Science.gov (United States)

    SUMMARY: The biomass of microalgae contains approximately 50% carbon, which is commonly obtained from the atmosphere, but can also be taken from commercial sources that produce CO2, such as coal-fired power plants. A study of operational demonstration projects is being undertak...

  13. Formation of silicon carbide nanorods from wood-based carbons

    NARCIS (Netherlands)

    Hata, T; Castro, [No Value; Fujisawa, M; Imamura, Y; Bonnamy, S; Bronsveld, P; Kikuchi, H

    2005-01-01

    Man-made ceramic wood similar to petrified wood found in nature can be used at high temperature as the high oxidation rate of carbon above 500 degrees C is suppressed by a mu m thin SiC coating similar to the shuttle's heat shield. Possible applications are in the field of energy production, e.g., g

  14. Algae Based Carbon Capture and Utilization feasibility study : - initial analysis of carbon capture effect based on Zhoushan case pre-study in China

    OpenAIRE

    Sen, Cong

    2012-01-01

    This pre-feasibility study was taken out by the co-operation with Zhejiang University, the CEU lab in Zhejiang University is taking researches of the algae based carbon dioxide capture technology, this report mainly aims to evaluate the GHG mitigation effect of this technology and give suggestions.   This study was carried out at Zhejiang University based on the Zhoushan islands waste incineration power plant project, the report presents the initial feasibility study for the algae based carbo...

  15. Nomex-derived activated carbon fibers as electrode materials in carbon based supercapacitors

    Science.gov (United States)

    Leitner, K.; Lerf, A.; Winter, M.; Besenhard, J. O.; Villar-Rodil, S.; Suárez-García, F.; Martínez-Alonso, A.; Tascón, J. M. D.

    Electrochemical characterization has been carried out for electrodes prepared of several activated carbon fiber samples derived from poly (m-phenylene isophthalamide) (Nomex) in an aqueous solution. Depending on the burn-off due to activation the BET surface area of the carbons was in the order of 1300-2800 m 2 g -1, providing an extensive network of micropores. Their capability as active material for supercapacitors was evaluated by using cyclic voltammetry and impedance spectroscopy. Values for the capacitance of 175 F g -1 in sulfuric acid were obtained. Further on, it was observed that the specific capacitance and the performance of the electrode increase significantly with increasing burn-off degree. We believe that this fact can be attributed to the increase of surface area and porosity with increasing burn-off.

  16. Carbon-Based Adsorbents for Postcombustion CO2 Capture: A Critical Review.

    Science.gov (United States)

    Creamer, Anne Elise; Gao, Bin

    2016-07-19

    The persistent increase in atmospheric CO2 from anthropogenic sources makes research directed toward carbon capture and storage imperative. Current liquid amine absorption technology has several drawbacks including hazardous byproducts and a high-energy requirement for regeneration; therefore, research is ongoing to develop more practical methods for capturing CO2 in postcombustion scenarios. The unique properties of carbon-based materials make them specifically promising for CO2 adsorption at low temperature and moderate to high partial pressure. This critical review aims to highlight the development of carbon-based solid sorbents for postcombustion CO2 capture. Specifically, it provides an overview of postcombustion CO2 capture processes with solid adsorbents and discusses a variety of carbon-based materials that could be used. This review focuses on low-cost pyrogenic carbon, activated carbon (AC), and metal-carbon composites for CO2 capture. Further, it touches upon the recent progress made to develop metal organic frameworks (MOFs) and carbon nanomaterials and their general CO2 sorption potential. PMID:27257991

  17. Carbon-Based Adsorbents for Postcombustion CO2 Capture: A Critical Review.

    Science.gov (United States)

    Creamer, Anne Elise; Gao, Bin

    2016-07-19

    The persistent increase in atmospheric CO2 from anthropogenic sources makes research directed toward carbon capture and storage imperative. Current liquid amine absorption technology has several drawbacks including hazardous byproducts and a high-energy requirement for regeneration; therefore, research is ongoing to develop more practical methods for capturing CO2 in postcombustion scenarios. The unique properties of carbon-based materials make them specifically promising for CO2 adsorption at low temperature and moderate to high partial pressure. This critical review aims to highlight the development of carbon-based solid sorbents for postcombustion CO2 capture. Specifically, it provides an overview of postcombustion CO2 capture processes with solid adsorbents and discusses a variety of carbon-based materials that could be used. This review focuses on low-cost pyrogenic carbon, activated carbon (AC), and metal-carbon composites for CO2 capture. Further, it touches upon the recent progress made to develop metal organic frameworks (MOFs) and carbon nanomaterials and their general CO2 sorption potential.

  18. Glucose Biosensor Based on a Glassy Carbon Electrode Modified with Polythionine and Multiwalled Carbon Nanotubes

    OpenAIRE

    Wenwei Tang; Lei Li; Lujun Wu; Jiemin Gong; Xinping Zeng

    2014-01-01

    A novel glucose biosensor was fabricated. The first layer of the biosensor was polythionine, which was formed by the electrochemical polymerisation of the thionine monomer on a glassy carbon electrode. The remaining layers were coated with chitosan-MWCNTs, GOx, and the chitosan-PTFE film in sequence. The MWCNTs embedded in FAD were like "conductive wires" connecting FAD with electrode, reduced the distance between them and were propitious to fast direct electron transfer. Combining with good ...

  19. Carbon Storage in an Extensive Karst-distributed Region of Southwestern China based on Multiple Methods

    Science.gov (United States)

    Guo, C.; Wu, Y.; Yang, H.; Ni, J.

    2015-12-01

    Accurate estimation of carbon storage is crucial to better understand the processes of global and regional carbon cycles and to more precisely project ecological and economic scenarios for the future. Southwestern China has broadly and continuously distribution of karst landscapes with harsh and fragile habitats which might lead to rocky desertification, an ecological disaster which has significantly hindered vegetation succession and economic development in karst regions of southwestern China. In this study we evaluated the carbon storage in eight political divisions of southwestern China based on four methods: forest inventory, carbon density based on field investigations, CASA model driven by remote sensing data, and BIOME4/LPJ global vegetation models driven by climate data. The results show that: (1) The total vegetation carbon storage (including agricultural ecosystem) is 6763.97 Tg C based on the carbon density, and the soil organic carbon (SOC) storage (above 20cm depth) is 12475.72 Tg C. Sichuan Province (including Chongqing) possess the highest carbon storage in both vegetation and soil (1736.47 Tg C and 4056.56 Tg C, respectively) among the eight political divisions because of the higher carbon density and larger distribution area. The vegetation carbon storage in Hunan Province is the smallest (565.30 Tg C), and the smallest SOC storage (1127.40 Tg C) is in Guangdong Province; (2) Based on forest inventory data, the total aboveground carbon storage in the woody vegetation is 2103.29 Tg C. The carbon storage in Yunnan Province (819.01 Tg C) is significantly higher than other areas while tropical rainforests and seasonal forests in Yunnan contribute the maximum of the woody vegetation carbon storage (account for 62.40% of the total). (3) The net primary production (NPP) simulated by the CASA model is 68.57 Tg C/yr, while the forest NPP in the non-karst region (account for 72.50% of the total) is higher than that in the karst region. (4) BIOME4 and LPJ

  20. Breakthrough CO₂ adsorption in bio-based activated carbons.

    Science.gov (United States)

    Shahkarami, Sepideh; Azargohar, Ramin; Dalai, Ajay K; Soltan, Jafar

    2015-08-01

    In this work, the effects of different methods of activation on CO2 adsorption performance of activated carbon were studied. Activated carbons were prepared from biochar, obtained from fast pyrolysis of white wood, using three different activation methods of steam activation, CO2 activation and Potassium hydroxide (KOH) activation. CO2 adsorption behavior of the produced activated carbons was studied in a fixed-bed reactor set-up at atmospheric pressure, temperature range of 25-65°C and inlet CO2 concentration range of 10-30 mol% in He to determine the effects of the surface area, porosity and surface chemistry on adsorption capacity of the samples. Characterization of the micropore and mesopore texture was carried out using N2 and CO2 adsorption at 77 and 273 K, respectively. Central composite design was used to evaluate the combined effects of temperature and concentration of CO2 on the adsorption behavior of the adsorbents. The KOH activated carbon with a total micropore volume of 0.62 cm(3)/g and surface area of 1400 m(2)/g had the highest CO2 adsorption capacity of 1.8 mol/kg due to its microporous structure and high surface area under the optimized experimental conditions of 30 mol% CO2 and 25°C. The performance of the adsorbents in multi-cyclic adsorption process was also assessed and the adsorption capacity of KOH and CO2 activated carbons remained remarkably stable after 50 cycles with low temperature (160°C) regeneration. PMID:26257348