Adjustable Platform Research Articles

Towards a Carbon-Neutral Energy Sector: Opportunities and Challenges of Coordinated Bioenergy Supply Chains-A PSE Approach

The electricity generation sector needs to reduce its environmental impact and dependence on fossil fuel, mainly from coal. Biomass is one of the most promising future options to produce electricity, given its potential contribution to climate change mitigation. Even though biomass is an old source of energy, it is not yet a well-established commodity. The use of biomass in large centralised systems requires the establishment of delivery channels to provide the desired feedstock with the necessary attributes, at the right time and place. In terms of time to deployment and cost of the solution, co-combustion/co-gasification of biomass and coal are presented as transition and short-medium term alternatives towards a carbon-neutral energy sector. Hence, there is a need to assess an effective introduction of co-combustion/co-gasification projects in the current electricity production share. The purpose of this work is to review recent steps in Process Systems Engineering towards bringing into reality individualised and ad-hoc solutions, by building a common but adjustable design platform to tailored approaches of biomass-based supply chains. Current solutions and the latest developments are presented and future needs under study are also identified.

Characterization of intracochlear rupture forces in fresh human cadaveric cochleae.

To develop a method to measure the forces required for a probe to translocate from the scala tympani (ST) to the scala vestibuli (SV) in fresh human cochleae. Translocation of cochlear implant electrodes from the ST to the SV may lead to suboptimal audiologic outcomes. Prior work investigating the rupture forces of human intracochlear membranes comes from a single study conducted on isolated ex vivo cadaveric specimens. Fresh (postmortem <120 h), nonfixed, never-frozen human temporal bones underwent preparation consisting of surgical isolation of the cochleae and exposure of the osseous spiral lamina, basilar membrane, and Reissner's membrane complex by removing bone covering the ST and the SV. Each isolated cochlea was mounted to a force sensor using an adjustable mounting platform. A 300-μm-diameter ball-tipped probe was attached to a piezoelectric linear motor and advanced at 1 mm/s from the ST to the SV while recording force from the load cell concurrent with video. Ten specimens were successfully exposed and analyzed. The range of rupture forces was 42 to 122 mN, with a mean of 88 mN. Nine of the 10 specimens failed via simple puncture, whereas one failed by being avulsed from its medial attachment. Using a novel technique, we report the forces required to translocate a model of an electrode from the ST to the SV. Correlation to human perceptual ability is necessary to determine if a surgeon can detect such translocation during cochlear implant surgery.

Selective synthesis and redox sequence of a heterobimetallic nickel/copper complex of the noninnocent Siamese-twin porphyrin.

The Siamese-twin porphyrin (1H4) is a redox noninnocent pyrazole-expanded porphyrin with two equivalent dibasic {N4} binding sites. It is now shown that its selective monometalation can be achieved to give the nickel(II) complex 1H2Ni with the second {N4} site devoid of a metal ion. This intermediate is then cleanly converted to 1Ni2 and to the first heterobimetallic Siamese-twin porphyrin 1CuNi. Structural characterization of 1H2Ni shows that it has the same helical structure previously seen for 1Cu2, 1Ni2, and free base 1H6(2+). Titration experiments suggest that the metal-devoid pocket of 1H2Ni can accommodate two additional protons, giving [1H4Ni](2+). Both bimetallic complexes 1Ni2 and 1CuNi feature rich redox chemistry, similar to the recently reported 1Cu2, including two chemically reversible oxidations at moderate potentials between -0.3 and +0.5 V (vs Cp2Fe/Cp2Fe(+)). The locus of these oxidations, in singly oxidized [1Ni2](+) and [1CuNi](+) as well as twice oxidized [1CuNi](2+), has been experimentally derived from comparison of the electrochemical properties of the complete series of complexes 1Cu2, 1Ni2, and 1CuNi, and from electron paramagnetic resonance (EPR) spectroscopy and X-ray absorption spectroscopy (XAS) (Ni and Cu K edges). All redox events are largely ligand-based, and in heterobimetallic 1CuNi, the first oxidation takes place within its Cu-subunit, while the second oxidation then occurs in its Ni-subunit. Adding pyridine to solutions of [1Ni2](+) and [1CuNi](2+) cleanly converts them to metal-oxidized redox isomers with axial EPR spectra typical for Ni(III) having significant dz(2)(1) character, reflecting close similarity with nickel complexes of common porphyrins. The possibility of selectively synthesizing heterobimetallic complexes 1MNi from a symmetric binucleating ligand scaffold, with the unusual situation of three distinct contiguous redox sites (M, Ni, and the porphyrin-like ligand), further expands the Siamese-twin porphyrin's potential to serve as an adjustable platform for multielectron redox processes in chemical catalysis and in electronic applications.

Resistance exercise heart rate recovery in youth with Prader‐Willi syndrome, nonsyndromal obese children and lean controls (881.13)

Prader‐Willi Syndrome (PWS) is a genetic disorder characterized by excess adiposity, low lean mass and hypotonia. Heart rate recovery (HRR), a determinant of all‐cause mortality, is slower in PWS in response to endurance exercise. This study examined how adiposity and PWS influence resistance exercise HRR. Eight PWS youth (age=11.5±3.5 y, body fat=44.1±3.9 %) and 16 nonsyndromal obese (OB: age=9.5±1.2 y, body fat=39.5±4.5 %) and 12 lean (LN: age=9.1±1.2 y, body fat=17.8±5.1 %) children completed six sets of a bench‐stepping protocol. Each set consisted of 10 steps per leg onto an adjustable platform (~20% of stature) while donning a weighted vest (~50% of lean body mass), followed by one minute of rest. HRR value (HRRV) was calculated as the difference between test termination HR and HR one minute after exercise. One‐way ANOVA showed PWS had a significantly lower HRRV (44±13 beats) compared to OB (63±20 beats; p=0.035) and LN (63±13 beats; p=0.044). Similar to previous research in submaximal endurance exercise, nonsyndromal OB and LN children recovered faster than PWS, suggesting adiposity alone did not affect resistance exercise HRR. The lower HRRV in PWS may be attributed to poor cardiovascular fitness and/or autonomic nervous system dysfunction inherent to the syndrome. Further, resistance exercise HRRVs appeared comparable to previously studied endurance exercise HRRVs in youth.Grant Funding Source: Supported by USAMRAA Award W81XWH‐08‐1‐0025

Controllable 3D display system based on frontal projection lenticular screen

A novel auto-stereoscopic three-dimensional (3D) projection display system based on the frontal projection lenticular screen is demonstrated. It can provide high real 3D experiences and the freedom of interaction. In the demonstrated system, the content can be changed and the dense of viewing points can be freely adjusted according to the viewers’ demand. The high dense viewing points can provide smooth motion parallax and larger image depth without blurry. The basic principle of stereoscopic display is described firstly. Then, design architectures including hardware and software are demonstrated. The system consists of a frontal projection lenticular screen, an optimally designed projector-array and a set of multi-channel image processors. The parameters of the frontal projection lenticular screen are based on the demand of viewing such as the viewing distance and the width of view zones. Each projector is arranged on an adjustable platform. The set of multi-channel image processors are made up of six PCs. One of them is used as the main controller, the other five client PCs can process 30 channel signals and transmit them to the projector-array. Then a natural 3D scene will be perceived based on the frontal projection lenticular screen with more than 1.5 m image depth in real time. The control section is presented in detail, including parallax adjustment, system synchronization, distortion correction, etc. Experimental results demonstrate the effectiveness of this novel controllable 3D display system.

Microwave System for Head Imaging

A wideband microwave system for head imaging is presented. The system includes an array of 16 corrugated tapered slot antennas that are installed on an adjustable platform. A switching device is used to enable the antennas to sequentially send a wideband 1-4 GHz microwave signal and capture the backscattered signals. Those signals are recorded using suitably designed virtual instrument software architecture. To test the capability of the system to detect brain injuries, a low-cost mixture of materials that emulate the frequency-dispersive electrical properties of the major brain tissues across the frequency band 1-4 GHz are used to construct a realistic-shape head phantom. A target that emulates a realistic hemorrhage stroke is fabricated and inserted in two different locations inside the fabricated head phantom. A preprocessing algorithm that utilizes the symmetry of the two halves of human head is used to extract the target response from the background reflections. A post-processing confocal algorithm is used to get an image of the phantom and to accurately detect the presence and location of the stroke.

Wideband and Unidirectional Folded Antenna for Heart Failure Detection System

A wideband folded antenna, which is specifically designed for an early heart failure detection system operating at the ultra-high frequency (UHF) band, is presented. The design procedure starts with a planar structure that includes a loop antenna, a dual monopole, and a loaded parasitic patch. To significantly reduce the size of the antenna and achieve directional radiation as needed for the intended application, the planar structure is folded to form a three-dimensional antenna with the dimensions $0.1\lambda\times 0.29\lambda\times 0.09\lambda$ , where $\lambda$ is the wavelength at the lowest operating frequency. The final tested antenna achieves a peak gain of 4.2 dBi, front-to-back ratio of 7–13 dB and efficiency of more than 87% over 62% fractional bandwidth (560–1060 MHz) at 10-dB return-loss reference. The antenna in addition to a compact microwave transceiver and an adjustable platform are then used to build a monostatic-radar-based heart failure detection system. The system is tested on an artificial torso phantom to verify the potential of such a system in the early detection of heart failure. The used imaging algorithm and obtained promising results are reported in the letter.

Three-Dimensional Open-Ended Slot Antenna for Heart Failure Detection System Employing Differential Technique

The design of a folded open-ended slot antenna for an early-stage congestive heart failure (CHF) detection system operating at ultra-high frequency (UHF) is presented. The antenna is formed using a three-dimensional open-ended slot with a compact size of 0.24 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.09λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.04 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> (λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the lowest operating frequency of the antenna), and a slotted microstrip feeder used to achieve wide operating bandwidth of 58% (550-1000 MHz). A CHF detection system is then built using the proposed antenna, a compact microwave sensor, and a differential detection technique. The main objective of such a system is to map the torso area searching for any fluid accumulation in the lungs as the main symptom of CHF. To that end, a pair of the proposed antenna is attached to an adjustable platform to vertically scan the torso. A differential detection technique is applied on the backscattered signals to map the scattering profile of the torso and detect any changes in the electrical properties of the lungs caused by fluid accumulation. A detection threshold is applied to differentiate between healthy and unhealthy cases. The obtained images have a pixel resolution of 0.1 cm in depth and 1 cm in height. The experimental results on an artificial torso indicate that the system can detect fluid differences as small as 4 mL, with a measurement error of less than 3%.

Experimental study on subaperture testing with iterative triangulation algorithm

Applying the iterative triangulation stitching algorithm, we provide an experimental demonstration by testing a Φ120 mm flat mirror, a Φ1450 mm off-axis parabolic mirror and a convex hyperboloid mirror. By comparing the stitching results with the self-examine subaperture, it shows that the reconstruction results are in consistent with that of the subaperture testing. As all the experiments are conducted with a 5-dof adjustment platform with big adjustment errors, it proves that using the above mentioned algorithm, the subaperture stitching can be easily performed without a precise positioning system. In addition, with the algorithm, we accomplish the coordinate unification between the testing and processing that makes it possible to guide the processing by the stitching result.

Design and Assembly of an Antenna Demonstration System [Education Column

This paper describes the design, assembly, and operation of a self-contained wireless demonstration system that required only dc power supplies. The system demonstrated polarization effects, radiation patterns, gain, directivity, and signal interference from environmental barriers for dipole, corner reflector (simulated antenna array), Quagi, and embedded patch antennas. The system included an RF oscillator, high-frequency amplifiers, RF bandpass filters, a signal-strength indicator, and multiple adjustable antenna-mounting platforms.

Subway Ventilation and Air Conditioning System Operating Mode of Study

In this study, a regional standard practice in the construction of the subway stations and tunnels for the study, with the SES software, a mathematical model of the closed system, platform screen door (PSD) systems, hybrid air conditioning system (adjustable ventilated platform doors [1]) to run the program properly simulate the conditions. Analysis of annual energy consumption of each system to be; while the traditional mode of operation of the system to explore and optimization; ventilation and air conditioning system for the new subway rational design and operation and management of scientific data to provide valuable information..

Robot for Boiler Header Inspection “LS-01”

Inspection of boiler headers is routinely being performed in Tenaga Nasional Berhad (TNB) thermal power plants. It is very important to inspect boiler header from time to time to check for signs of possible failures because they are thick walled and exposed to various operating conditions. The currently used method is to insert a fiber optic camera probe into the boiler header entry manually by human. This work is very tedious and the inspector often has difficulties to acquire full coverage of the inner wall images. Therefore, it is proposed that a robotic system is developed to carry the fibre optic probe into the boiler headers and assist in a more efficient and reliable boiler header inspection. The developed robot prototype must be small enough to enter the header and must also have the capability to traverse the whole length of boiler header while carrying the existing fibre optic probe as well as cater for boiler header with different diameters. LS-01, presented in this paper, is the first boiler header inspection robot prototype developed, equipped with semi-intelligent system and adjustable entry platform, and is capable of traversing inside boiler headers with various tube configurations. It has been tested in accordance with the engineering requirements set by TNB. Testing has shown the potential of the robot to be applied in a real boiler header inspection processes.

Subway Ventilation and Air Conditioning System Operating Mode of Study

In this study, a regional standard practice in the construction of the subway stations and tunnels for the study, with the SES software, a mathematical model of the closed system, platform screen door (PSD) systems, hybrid air conditioning system (adjustable ventilated platform doors [1]) to run the program properly simulate the conditions. Analysis of annual energy consumption of each system to be; while the traditional mode of operation of the system to explore and optimization; ventilation and air conditioning system for the new subway rational design and operation and management of scientific data to provide valuable information..

MO-D-BRB-10: Optical Surface Imaging for Online Rotation Correction and Real-Time Motion Monitoring with Threshold Gating for Frameless Cranial Stereotactic Radiosurgery

Purpose: To develop an image‐guided procedure for online head‐rotation correction and real‐time motion monitoring with threshold gating for clinical frameless stereotactic radiosurgery(SRS) using video‐based optical 3D surfaceimaging (AlignRT) to ensure accurate tumor localization and clinically‐acceptable head motion at all treatment couch angles during treatment. Methods: Eight patients, immobilized with a deep‐head mold and a mouth‐piece fixed to the couch, were treated with single‐fraction frameless SRS. The planning target volume was defined by a 3.0mm‐margin around the gross tumor volume for these patients with brainmetastasis. A ceiling‐mounted AlignRT system with three camera pods was used to correct residual head rotation before cone‐beam computed tomography(CBCT) setup, verify setup at all treatment couch angles, and monitor the head motion with 1.0mm gating threshold for beam hold. The external contour of the planing CT and on‐site surface reference images were used for setup verification and motion monitoring, respectively, using the maximum visible skin surface within the entire mid‐to‐upper face as the region of interest. An anthropomorphous head phantom and an adjustable platform (accuracy of 0.1 mm) were used to determine the geometric accuracy of frameless setup procedure and AlignRT motion detection. Results: The phantom experiment shows that the motion detection accuracy was less than 0.1 mm. For these patients, <1 degree head rotation was achieved at the setup by using surface‐image‐guided head repositioning. The patient head motion was found to be <1.0mm for 98% of the time after CBCT setup, while the beam‐hold gating was used for <1% of beam‐on time. The required workload and machine time of this procedure are similar to those of conventional frame‐based SRS. Conclusions: This non‐invasive frameless SRS procedure provides accurate and reliable means to perform clinical SRS. The image‐guided setup and motion control provides adequate accuracy, yet more convenient to the patients, comparing with frame‐based SRS. This research is in part supported by VisionRT through a clinical research agreement.

Enhancement of Adaptability of Parallel Kinematic Machines With an Adjustable Platform

The design of an industrial robot involves a number of conflicting objectives in general. A parallel kinematic machine (PKM) is known to achieve high precision and heavy load capacity but with the sacrifice of large workspace and high dexterity. Therefore, existing PKMs are mostly dedicated to a specific task with relatively poor adaptability to task variations. In this paper, the concept of an adjustable platform is proposed to enhance the adaptability of a PKM for various tasks. It is demonstrated that the adjustment of the dimensions of a base platform or end-effector platform has a significant impact on the performance of a PKM including its workspace and overall stiffness distribution. Both offline and online adjustment modes are presented. The offline adjustment brings a new dimension for reconfigurability and thus increases the versatility of a parallel robot for different tasks. The online adjustment turns a parallel robot into a redundant PKM, and therefore its overall performance against task requirements can be improved. A planar PKM and a Stewart robot with an adjustable platform are used as case studies in order to demonstrate the advantages of the proposed concept.

Cervical Spine Imaging Using Mini–C-arm Fluoroscopy

Direct and scatter radiation was measured during cadaveric cervical spine imaging with a mini-C-arm fluoroscope. The purpose of this study was to evaluate radiation exposure to the patient and surgeon when using a mini-C-arm fluoroscope to image the cervical spine. Prior studies have quantified radiation exposure using large C-arm fluoroscopy during procedures involving the cervical, thoracic, and lumbar spine. To our knowledge, no studies have quantified radiation exposure during mini-C-arm fluoroscopy of the cervical spine. A calibrated OEC MINI 6800 C-arm was used to image a prepared cadaveric cervical spine specimen, which included the skull. The specimen was suspended on an adjustable polycarbonate platform. Thirteen film badge dosimeters were mounted at various positions and angles to detect direct and scatter radiation. Recorded exposure levels were collected and analyzed. Surgeon exposures from the mini-C-arm were considerably lower than previously reported with the standard C-arm, but nonetheless concerning. Patient exposures were considerable and not always reduced compared with values from the standard C-arm. The kVp generated by the mini-C-arm was similar to the standard C-arm. Dosimeters mounted in the same plane recorded dissimilar amounts of radiation during the same test, which underscores the influence of shape on the amount of reflected scatter. Although using a mini-C-arm unit may reduce exposure levels, substantial exposure to both patient and staff is still achievable. Use of a mini-C-arm for cervical spine imaging reduces exposure to the surgeon more effectively than to the patient. To lower the risk of radiation exposure in the cadaver laboratory, a mini-C-arm should be used in each instance that offers appropriate visualization. In the operating room, all appropriate radiation dose-reducing measures should be strictly enforced by supervising physicians to minimize risk to patients, medical staff, and themselves.

Patient and Surgeon Radiation Exposure: Comparison of Standard and Mini-C-Arm Fluoroscopy

Background: Use of c-arm fluoroscopy is common in the operating room, outpatient clinic, and emergency department. Consequently, there is a concern regarding radiation exposure. Mini-c-arm fluoroscopes have gained popularity; however, few studies have quantified exposure during mini-c-arm imaging of a body part larger than a hand or wrist. The purpose of this study was to measure radiation exposure sustained by the patient and surgeon during the use of large and mini-c-arm fluoroscopy of an ankle specimen. Methods: Standard and mini-c-arm fluoroscopes were used to image a cadaver ankle specimen, which was suspended on an adjustable platform. Dosimeters were mounted at specific positions and angulations to detect direct and scatter radiation. Testing was conducted under various scenarios that altered the proximity of the specimen and the radiation source. We attempted to capture a range of exposure data under conditions ranging from a best to a worst-case scenario, as one may encounter in a procedural setting. Results: With all configurations tested, measurable exposure during use of the large-c-arm fluoroscope was considerably higher than that during use of the mini-c-arm fluoroscope. Patient and surgeon exposure was notably amplified when the specimen was positioned closer to the x-ray source. The exposure values that we measured during ankle fluoroscopy were consistently higher than the exposure values that have been recorded previously during hand or wrist imaging. Conclusions: Exposure of the patient and surgeon to radiation depends on the tissue density and the shape of the imaged extremity. Elevated exposure levels can be expected when larger body parts are imaged or when the extremity is positioned closer to the x-ray source. When it is possible to satisfactorily image an extremity with use of the mini c-arm, it should be chosen over its larger counterpart. Clinical Relevance: Orthopaedists should exercise caution, and consistently follow radiation safety guidelines, when using c-arm fluoroscopes because there is a real risk of radiation exposure.

Experimental platform to assess the weight relief lifting and sitting pivot transfer movements

Several times per day, manual wheelchair (MW) users perform weight relief lifting or sitting pivot transfer movements using only their upper limbs. These motions generate significant articular constraints that could lead to musculo-skeletal disorders. The geometry of the hardware configurations of manual wheelchairs influence the movements produced by these MW users. To evaluate this influence, it was necessary to design an instrumented and adjustable experimental platform that would allow the articular efforts of the weight relief lifting and sitting pivot transfer movements to be estimated. The experimental platform that we have developed is composed of 5 adjustable modules: 2 seat modules, 2 armrest modules, and 1 footrest module. These modules are instrumented to allow the effort exerted by the subjects on their environment to be measured, while a motion capture system records the position of reflective markers positioned on the subject. The measured data, coupled with kinematic, anthropometric and dynamic models, make it possible to estimate the articular effort. The results reported in the literature confirm our results, thus validating our method and our instrumentation.

Cervical Spine Imaging Using Standard C-Arm Fluoroscopy

A cadaveric cervical spine specimen is imaged with a standard C-arm fluoroscope during a simulated procedure. Patient and surgeon exposure to radiation is estimated by placing dosimeters at various locations in 3-dimensional space. The purpose of this study was to evaluate radiation exposure to patient and surgeon when using C-arm fluoroscopy during a simulated cadaveric surgical procedure involving the cervical spine. The use of mobile fluoroscopy has become commonplace in orthopaedics. With the current trend towards minimal access techniques, fluoroscopy has become requisite to achieving satisfactory outcomes. Studies have shown that spine surgeons may be at elevated risk for radiation exposure compared to other orthopaedists. Exposure while using C-arm fluoroscopy for procedures involving the pelvis, as well as thoracic and lumbar spine has been documented. However, there are no equivalent studies that evaluate exposure during cervical spine imaging. A standard OEC 9800 C-arm was used to image a prepared cadaveric cervical spine specimen, which was suspended on an adjustable platform. Film badge dosimeters were mounted at various positions and angles to detect direct and scatter radiation. Testing was conducted in various radiation dose mapping "scenarios." The configurations tested altered the proximity of the specimen and jig relative to the radiation source. We attempted to capture radiation exposure in various locations, from a best-case to a worst-case scenario, as may be realistically encountered in a procedural setting. RESULTS.: Potential exposure to the patient and surgeon were consistently measurable, and of concern. As the imaged specimen was positioned closer to the radiation source, exposure to the patient was markedly amplified. Exposure to the surgeon did not increase as dramatically. There was a great degree of variability in the exposure doses recorded by the peripheral dosimeters. Even dosimeters that were placed in the same plane diverged widely in their measured exposure. This highlights the influence of the shape of the imaged specimen on reflected scatter. Scatter radiation doses on both sides of the specimen were similar. Care should be taken when working on both sides of the imaged subject. Considerable radiation exposure can be encountered when working with a C-arm fluoroscope if appropriate precautions are not observed. All appropriate radiation dose-reducing measures should be strictly enforced by the supervising physician to minimize risk to the patient and the medical team.

The action of plantar pressure on flexion reflex pathways in the isolated human spinal cord

Objective To investigate the conditioning effects of plantar pressure on flexion reflex excitability in patients with motor complete spinal cord injury (SCI). Methods In five motor complete SCI subjects, the non-nociceptive flexion reflex was evoked via electrical stimulation of the right sural nerve and was recorded from the ipsilateral tibialis anterior muscle. Pressure ranging from 25 to 80 kPa was applied to the metatarsal heads through an adjustable platform incorporated into a foot rest and a comparison of the reflex size made between control conditions and during pressure application. Results In all subjects, a significant depression of the long latency flexion reflex was observed when pressure was applied to the foot sole. The short latency flexion reflex appearing at latencies less than 100 ms was absent in all patients. Conclusions The results demonstrate that flexion reflex excitability in the isolated human spinal cord can be modulated by adequate activation of plantar mechanoreceptors. Significance Activation of plantar mechanoreceptors is a feature of normal standing and walking. Rehabilitation for standing and walking in SCI commonly uses body weight support based protocols. The strong inhibitory actions of plantar pressure on reflex pathways in the isolated human spinal cord suggest that sensory feedback from the foot sole may be an important factor in successful rehabilitation of standing and stepping in SCI patients.