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Canfor, a producer of lumber, pulp and paper needed a solution to replace aging 30-inch (760mm) fiberglass reinforced pipe. A new PE-RT product now expands PE into industrial applications requiring resistance to high temperatures and having a Hydrostatic Design Basis (HDB) of 800psi (55 bar) at 180°F (82.2°C). Through chemical processes, Canfor cooks, washes, and extracts pulp fiber from wood that results in both acidic and caustic effluent with temperatures normally in the 50–60°C range or as high as 70–75°C. Traditional fiberglass pipes have experienced repeated joint failures over time, whereas heat-fused HDPE pipe provides solutions reducing unnecessary maintenance and a longer service life. Standard PE4710 High Density Polyethylene Pipes (HDPE) have pressure ratings limited to 140°F (60°C) and are not normally acceptable for such high temperature acidic and caustic effluent. Additionally, the potential for higher oxidation-reduction potential (ORP) from residual chlorine levels and bleaching also justified turning to a different material based on the potential oxidative attack at high temperatures. The new PE-RT resin protects against oxidative attacks at high temperatures and the flexible heat-fused HDPE pipe provides considerable cost savings during installation. Compared to fiberglass, up to eight 40-foot lengths of HDPE pipe can be joined by heat fusion per day, whereas only two 6-meter (20-foot) lengths of FRP pipe can be wrapped per day. The presentation will highlight photos during the installation process and report the advantages of using the new pipe material. This project provides reference for expanding HDPE pipe into new applications using PE-RT materials.

This study reports our experience of developing a series of biomedical engineering (BME) courses having active and experiential learning components in an interdisciplinary learning environment. In the first course, BME465: biomechanics, students were immersed in a simulation laboratory setting involving mannequins that are currently used for teaching in the School of Nursing. Each team identified possible technological challenges directly related to the biomechanics of the mannequin and presented an improvement overcoming the challenge. This approach of exposing engineering students to a problem in a clinical learning environment enhanced the adaptive and experiential learning capabilities of the course. In the following semester, through BME448: medical devices, engineering students were partnered with nursing students and exposed to simulation scenarios and real-world clinical settings. They were required to identify three unmet needs in the real-world clinical settings and propose a viable engineering solution. This approach helped BME students to understand and employ real-world applications of engineering principles in problem solving while being exposed to an interdisciplinary collaborative environment. A final step was for engineering students to execute their proposed solution from either BME465 or BME448 courses by undertaking it as their capstone senior design project (ENGR401-402). Overall, the inclusion of clinical immersions in interdisciplinary teams in a series of courses not only allowed the integration of active and experiential learning in continuity but also offered engineers more practice of their profession, adaptive expertise, and an understanding of roles and expertise of other professionals involved in enhancement of healthcare and patient safety.

Computational Pipeline Monitoring (CPM) leak detection in liquid pipelines can be unreliable or have a high number of false alarms during transient hydraulic events. This paper presents techniques for avoiding these false alarms and for improving leak detectability during steady state operations. Application of this approach has improved both the sensitivity and reliability of CPM-based leak detection systems. When a pipeline is in steady-state operation, the leak detection thresholds can be reduced. When a transient is detected, the thresholds are increased to a higher value. Because of known errors in data measurement and the time at which the measurement was made, large uncertainties in the line-pack prediction can exist during these transient events. In this paper, CPM reliability is improved using dual thresholds; tight threshold for near steady state and relaxed threshold for transient operation. In the presented study, different transient triggers in a pipeline have been implemented to the dual threshold method in order to show the effect of transient thresholds on the reliability of the CPM models or the reduction in the number of false alarms. When the CPM model determines that a transient event is occurring, the imbalance threshold is increased to a pre-set higher value. The transient threshold will remain high until the transient event diminishes, then the thresholds will return to their original steady-state value after a pre-set wait period. This applies to each leak detection window and to each flow meter-to-flow meter section in the CPM model. Detailed information about the dual thresholds approach and the transient triggers is provided in the full paper. Results from the implementation of this method and the quantitative improvement of the CPM reliability and sensitivity will also be presented.Copyright © 2014 by ASME

This paper presents the development of an exergy and thermoeconomic analysis of a wheat flour agro-industrial plant, which was aimed to evaluate the energy use and establish the operation cost of its components, and to understand the cost formation process and the cost flow. It was found that throughout the production process exists an exergy destruction ratio of 95,08 %. It identified improvement opportunities in relation to cost, has recommended alterations with regard matter flows or an economic investment for change some components with low exergoeconomic factors: 2% planer of wheat bran, 3% knurled roller grinding benches and 5% smooth roller grinding benches. Copyright © 2015 by ASME. American Society of Mechanical Engineers (ASME)

PHWR (also known as CANDU) primary heat transport (PHT) system is to make the pressurized heavy water through the reactor fuel channel, take away the heat produced by the fission of uranium fuel (i.e. fuel cooling), through the reactor feeder pipes, into the Steam Generator. PHWR reactor feeder flow value are a very important parameters, which are stable and meets the requirements of the design, plays an important role in the NPP safe operation. This paper summarize the Qinshan CANDU reactor feeder flow measurement in practice, based on the feeder flow measurement principle and measurement data are analyzed and studied, including feeder flow measurement stages, site preparation of material and equipment, data measurement methods, data analysis methods, dealing with flow measurement uncertainties, and some other key point need to be attention. The Qinshan CANDU reactor feeder flow measurement schedules create the same type of CANDU units commissioning records in the world, which is not only shorten the commissioning critical path time, but also laid the foundation for the safety operation. The reasons for the Qinshan success are also to analyze in this article. Finally, this paper based on the experience of Qinshan CANDU feeder flow measurement, put forward some suggestions on organization and implementation to minimize human error and increase its efficiency, and hope for the help on the similar work area in the future.

Conversion of citrus processing waste (CPW) generated during juice production into value added co-products is an important aspect of the juice industry as it offers a solution to waste disposal issues. Currently the practice of drying citrus waste to produce citrus pulp pellets (CPP) for use as cattle feed is profitable. However, until the recent rise in value, CPP value was marginal and often did not meet production costs. Another concern has been volatile organic emissions during CPP production. Only one third of the residual peel oil present in citrus waste is recovered during CPP production with most being vented to the atmosphere during drying and is a growing environmental concern. Improvements in limonene recovery and development of alternative value added co-products obtained from CPW could add substantial value to the citrus crop. For current CPP production, the energy required to dry CPW is the major cost involved and approximately 25 lb of limonene are obtained per ton of CPP produced. Since limonene is recovered during evaporation/concentration of pressed peel juice using a waste heat evaporator, little additional cost is associated with limonene recovery. The concentrated citrus molasses produced may be added back to the press cake or fermented to make ethanol, but only contains a third of the sugars in CPW that are fermentable by conventional yeast. While utilizing the entire CPW stream for ethanol using hydrolysis and fermentation is more involved, three times the amount of ethanol can be obtained compared to using press liquor alone. Most of the limonene must be removed as it inhibits fermentation. In the process developed 85–95% of the limonene contained in CPW can be removed and recovered by steam stripping. This greatly reduces concerns associated with the release of volatile organic compounds (VOCs) during processing of CPW and the limonene recovered has a value equal or greater than stripping costs. Using a mixture of enzymes and yeast, the CPW is then hydrolyzed and fermented simultaneously to produce ethanol followed by distillation to remove and recover the ethanol. Enzyme costs to hydrolyze and liquefy CPW have been reduced to less than a dollar per gallon of ethanol produced, and the economics for distillation are still being optimized. The distillation residues contain half the solids of raw citrus waste that can still be utilized as a CPP product. Other uses for the residues such as incorporation of the pectic materials into building product and paper additives, and ion exchange materials for wastewater remediation are also in development. Paper published with permission.

This paper describes the resin treatment system developed by Bucher Alimentech NZ Ltd. (BAN) for the treatment of Citrus Products containing pulp and cloud. These products can be pure juices, core or pulp washes, or peel extracts and comminutes. The system does not use filtration membranes to first clarify the feed stream, instead a pulp reduced stream containing cloud is treated through the resin beds. Processes including debittering, colour adjustment, and ratio adjustment are described. Benefits are defined. Paper published with permission.

In recent times, Origami has received an increasing research interest because of its capability to produce foldable tessellations and structures. This paper describes a new modular tetrahedral representation called “Kinetogami”. We embed the cuts and joining patterns into the crease pattern and create folded hinges across basic structural units (BSU), typically not done in Origami. We demonstrate sets of explicit 2D fabrication lay-outs and construction rules in order to fold reconfigurable structures and mechanisms in 3D by using a single flat paper sheet. The structural and combinatorial characteristics of Kinetogamic derivatives are further explored in a hierarchical manner. Inspired by Kinetogami, we design a family of multi-limbed tetrahedral robotic form that reconfigures and adapts. The kinematic properties of individual limbs are investigated and multiple gaits involving flipping, squatting/rising, squirming and slithering are synthesized for a representative hexapod robot. Our newly developed folding design paradigm provides affordances for a novel generation of robotic motion actuation and transformable reconfiguration.Copyright © 2012 by ASME

Creating highly articulated miniature structures requires assembling a large number of small parts. This is a very challenging task and increases cost of mechanical assemblies. Insert molding presents the possibility of creating a highly articulated structure in a single molding step. This can be accomplished by placing multiple metallic bearings in the mold and injecting plastic on top of them. In theory, this idea can generate a multi degree of freedom structures in just one processing step without requiring any post molding assembly operations. However, the polymer material has a tendency to shrink on top of the metal bearings and hence jam the joints. Hence, until now insert molding has not been used to create articulated structures. This paper presents a theoretical model for estimating the extent of joint jamming that occurs due to the shrinkage of the polymer on top of the metal bearings. The level of joint jamming is seen as the effective torque needed to overcome the friction in the revolute joints formed by insert molding. We then use this model to select the optimum design parameters which can be used to fabricate functional, highly articulating assemblies while meeting manufacturing constraints. Our analysis shows that the strength of weld-lines formed during the in-mold assembly process play a significant role in determining the minimum joint dimensions necessary for fabricating functional revolute joints. We have used the models and methods described in this paper to successfully fabricate the structure for a minimally invasive medical robot prototype with potential applications in neurosurgery. To the best of our knowledge, this is the first demonstration of building an articulated structure with multiple degrees of freedom using insert molding.

High-density citrus pulp is becoming increasingly popular in the beverage industry; however, its unique rheological behavior poses some challenges for its processing in heat exchangers, including high pressures resulting from its high viscosity and the difficulties producing an even mixture. The rheological behavior of 850 g/l citrus pulp has been studied at different temperatures between 20 °C and 80 °C and applied to computerized fluid dynamics (CFD) simulations of flow in circular pipes and annular heat exchangers in order to determine flow characteristics and solutions for pulp mixing. Paper published with permission.

Joint loading is a recently developed mechanical modality, which potentially provides a therapeutic regimen to activate bone formation and prevent degradation of joint tissues. To our knowledge, however, few joint loading devices are available for clinical or point-of-care applications. Using a voice-coil actuator, we developed an electromechanical loading system appropriate for human studies and preclinical trials that should prove both safe and effective. Two specific tasks for this loading system were development of loading conditions (magnitude and frequency) suitable for humans, and provision of a convenient and portable joint loading apparatus. Desktop devices have been previously designed to evaluate the effects of various loading conditions using small and large animals. However, a portable knee loading device is more desirable from a usability point of view. In this paper, we present such a device that is designed to be portable, providing a compact, user-friendly loader. The portable device was employed to evaluate its capabilities using a human knee model. The portable device was characterized for force-pulse width modulation duty cycle and loading frequency properties. The results demonstrate that the device is capable of producing the necessary magnitude of forces at appropriate frequencies to promote the stimulation of bone growth and which can be used in clinical studies for further evaluations.

Southern Gardens Citrus and the Florida Department of Environmental Protection (FDEP), in a cooperative effort at the Clewiston citrus processing facility, reduced SO2 emissions by 80% and particulate matter emissions by 73%. This project also reduced costly diesel fuel use by 25%, increased citrus pulp feed mill operation efficiency, and saved the company more than $4 million a year. Paper published with permission.

The interest in renewable and cleaner fuels has stimulated ethanol production in the last decades. Some of the drivers for that ever increasing production were the Brazilian Alcohol Program, Kyoto Protocol and the replacement in USA of the octane booster MBTE (methyl-tert-buthyl ether) for ethanol. The world’s largest producers of ethanol are The United States of America and Brazil, where the main sources are corn and sugar cane, respectively. Production flow via pipeline is the safest and most cost effective way to connect the producers, usually spread across the country, to the distribution terminals. However, in USA there are evidences that ethanol may have caused stress corrosion cracking (SCC) in pipelines and also in storage tanks. Controversially, in Brazil ethanol has been transported and stored since the 1970’s without any indication of SCC. The aim of this work is to evaluate the susceptibility of the steel API 5L X70 [1] to SCC in different ethanol (corn and sugar cane) using slow strain rate testing (SSRT). These tests were carried out on notched specimens according to NACE TM 0111 [2]. The SSRT results carried out in corn ethanol have shown a considerable reduction of plastic elongation and a mixed fracture micromechanism of quasi-cleavage and intergranular facets clearly indicating a susceptibility of the API 5L X70 steel to SCC. The SSRT also demonstrated that the carbon steel tested here is completely immune to SCC in sugar cane ethanol.

This paper presents the effect of indium (In) content on the melting temperature, wettabililty, dross formation, and oxidation characteristics of the Sn-2Ag-3Bi-xIn alloy. The melting temperature of the Sn-2Ag-3Bi-xIn alloy (2 ≤ x ≤ 6) was lower than 473 K. The melting range between the solidus and liquidus temperatures was approximately 20 K, irrespective of the indium content. As the indium content increased, the wetting time increased slightly and the maximum wetting force remained to be mostly constant. The dross formation decreased to approximately 50% when adding 1In to Sn-2Ag-3Bi, and no dross formation was observed in the case of Sn-2Ag-3Bi-xIn alloy (x ≥ 1.5) at 523 K for 180 min. Upon approaching the inside of the oxidized solder of the Sn-2Ag-3Bi-1.5In alloy from the surface, the O and In contents decreased and the Sn content increased based on depth profiling analysis using Auger electron spectroscopy (AES). The mechanism for restraining dross (Sn oxidation) of Sn-2Ag-3Bi alloy with addition of indium may be due to surface segregation of indium. This is due to the lower formation energy of indium oxide than those of Sn oxidation.

A work on the design and construction of biodiesel batch reactor with improved settling capability for production of biodiesel from fresh palm oil (FPO) and fresh vegetable oil (FVO) is presented. A centrifuge separator, 41 litres capacity, operating at 1400rpm was incorporated into the integrated reactor. Biodiesel production was done using transesterification method. Two experiments were carried out under different reaction conditions such as time and temperature to determine biodiesel yield. The optimum biodiesel yield was achieved at a reaction time of 56 minutes and reaction temperature of 140°F and a lower yield was gotten at a temperature of 131°F and 50 minutes. A clear yellow color was obtained at a temperature of 140°F. The centrifuge achieved separation and settling within an average of 55 minutes. A characterization test carried out to determine the biodiesel density, specific density, flash point, pour point, and cloud point showed that the produced biodiesel agreed with the ASTMD 6751 standard for biodiesel test and have similar properties with conventional diesel which can therefore be used in diesel engines so as to reduce environmental pollution and encourage diversity in energy source.Copyright © 2014 by ASME

Cellulosic nanofibers have been electrospun with an antitumor agent Cisplatin. Cellulose acetate (CA) and Cisplatin were co-electrospun using a coaxial electrospinning system. For the outer sheath, a solution of 7.5wt% CA in Acetone and DMAc (2:1) was used. The inner core consisted of Cisplatin dissolved in DMF at a concentration of 5mg/ml. Drug-loaded nanofibers from Cellulose pulp (2wt%) dissolved in NMMO. H2O were also produced. The solutions were electrospun in a high voltage electric field of 25–30 kV. Characterization of neat and drug-loaded nanofibers was performed using Scanning electron microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS). The characterization studies have shown the formation of nanofibers having both sporadic beads with internal agglomeration and conjugation of Cisplatin on the nanofiber surfaces.Copyright © 2014 by ASME

Margarine as a raw material has a multiple uses in the production of bio-organic materials such as refined oil and butter. It passes through many industrial stages before beginning the process of refining and packaging it to the consumer. One of these important stages is the melting process, which wastes an immense amount of thermal power. The large rate of thermal power consumption occurs due to the huge reservoirs in which the margarine is stored (500 m3–1500 m3 Savola International Company-Suez Gulf region-Egypt). With drawing margarine from the reservoirs is a cost and time intensive process due to the solid state of margarine at environmental temperatures. Dry saturated steam is passed through the heat exchanger pipes inside the reservoir to melt the required amount of margarine. In some cases, this process can take up to 8 h in the summer and 12 h in the winter, which can be amplified by the loss of heat energy from the reservoir throughout the day, especially during the night periods. Moreover, steam boilers that use heavy fuel or natural gas can cause serious environmental damage as a result of emissions, such as the carbon oxide and nitrous oxide compounds. In contrast, solar energy is one of the cleanest and environmentally friendly renewable energies and should be invested as an alternative heat source for the melting process of margarine. As mentioned before, the melting of margarine is considered a heating process that consumes a huge amount of thermal energy. Therefore, solar thermal power can play a vital role in the process of melting margarine. Generally, temperature requirements of solar industrial heat applications range from 60 °C to 260 °C. Cylindrical PTC systems look very promising for delivering industrial heating process applications in the range of 95 °C–350 °C delivery temperature [1]. For solar thermal applications, the operating design conditions of solar collectors should be well above the desired operating conditions of the application to ensure stability of the operation. Therefore, flat plate collectors and evacuated tube collectors are eliminated from this study due to the previous reason and its lower efficiencies compared against the PTC [2]. This is why medium to medium–high temperature solar collectors are used [3,4]. Most of the production processes of the food industry such as milk products, vegetable, meat, fruits, and beer are run at temperatures below or near 100–130 °C. In addition, many cleaning processes such as pasteurizing, sterilizing, drying, hydrolyzing, distillation, washing, polymerization, and cooking processes are conducted under thermal applications [5,6]. Thus, switching to a renewable energy source, such as solar energy, can result in cost savings as well as decrease the negative impacts the production process has on the environment. The production process of margarine requires a large amount of heat in which solar thermal power is a viable and more cost effective source of energy. The problem originally emerged when Savola's company officials (Savola International Company in Margarine industrial Suez Gulf region-Egypt) decided to optimize the time, energy, and cost of the production process. They summarized their problems into the following points: The process of margarine melts takes more than 12 h to obtain 100–200 m3 of melted margarine per day. Which costs the equivalent amount of 476,120 m3 per day of natural gas (100,000 $/month). Reduction of CO2, NO2, and CO emissions is a must according to environmental laws. After reviewing the configuration of their heating process, using solar thermal power as a clean energy alternative seemed to be the most viable solution. Egypt has a great potential for solar energy. It is calculated that an amount of 6–7 kW h/m2/day of global radiation is in the Suez Gulf region-Egypt [8]. Therefore, it is very promising to utilize this vast amount of untapped solar energy in this industrial heating process. The aim of this research is to present a feasibility study, assessing the impact of using solar thermal power as an alternative source of energy in the margarine melting process. In this study, solar PTC is used instead of a conventional steam boiler. Water–steam and/or Therminol-VP1 [7] HTO are utilized through the PTC representing two different configurations. The data results of the conventional configuration (config1) are compared with the PTC–water steam configuration (config2) and PTC–Therminol configuration (config3) according to the hourly cost parameter ($/h). The study plan is organized as follows: The process configurations for the proposed systems are performed and the design limits are investigated. The mathematical model that represents the proposed systems is constructed. Three cases are compared (solar direct vapor generation (two configurations) was conventional configuration). Practical and analytical solutions for the process problems are studied and executed. solar desalination system (SDS) software package (a part of renewable energy desalination system (REDS) that were developed by the authors) was used to model all the system units [8–11]. 2. Margarine Melting Heating Process 2.1. The Process Problems. The problem began when Savola's-Egypt officials decided to evaluate the productive performance of their company. In their current configuration, a steam boiler running on fuels is used in the heating process. The company was faced with several problems identified as below. Wasted time, especially in the winter it requires melting about 100–300 m3 within approximately 12 h. This requires a significant amount of time before the canning process can begin. In addition, the steam boiler has to be operated during night hours to collect the melted margarine early in the morning before the canning process. It is noted that the fuel consumption is also very high, especially in the case of heavy fuel operations. As the average daily consumption reached 1 m3 or more, which is considered to be a high rate of consumption. The exhaust emissions resulting from the combustion inside the steam boiler today are unacceptable in the light of international regulations which intend to reduce global carbon emissions. Because of the temperature difference during the night especially in winter a large amount of thermal power gets wasted. This increases the operation time and the rate of fuel consumption. Thus, Savola's Egyptian officials contacted the authors to investigate and propose solutions to the existing inefficiencies, while at the same time decreasing the negative impact on the environment.

A modern paper machine is equipped with various finishing units e.g. calenders and coating units in order to produce better optical and printing properties. To accomplish these required properties paper is manipulated between two parallel mounted rolls. The contact area of these rolls is called a nip. The rolls are pressed together using hydraulic loading mechanism in order to achieve required pressure to paper web between the rolls. One of the most important nip unit driving parameter is linear load i.e. force per length. To compensate deflections, which are caused by line load and gravity, the rolls are crowned. In cases, where the total nip force surpass the gravity force of the roll the zero load condition exists. In the other words the roll floats freely and bearing clearances can place themselves arbitrary. To prevent misalignment due to bearing clearances and to achieve more accurate line load control a new closing procedure has been developed. The actual line load level is force-controlled while the approach maneuver of the roll is controlled using positioning sensors. Tampere University of Technology (TUT) has built up an experimental set-up to study both vibration phenomena and behavior of polymer roll cover material. This paper presents the equations and experimental results of a new nip closing procedure.

Computational modeling is very useful in biomechanics to simulate normal and pathologic joint function. It is also useful to determine the efficacies of various surgical procedures performed to treat joint pathologies and simulate their outcomes. Models can be used to estimate in situ measures such as contact pressure distributions that are difficult to acquire through experiments noninvasively. Currently, computational modeling is the only technique available to noninvasively evaluate in vivo joint contact mechanics [1]. However, most models make use of input parameters derived from various general sources such as literature, standards, or experiments and are, therefore, limited for patient-specific applications [2]. Joint injuries, whether ligaments or articular surface, are a significant problem and there is still a need for tools to effectively evaluate joint injuries and associated sequelae [3]. The ability to monitor the initiation and progression of joint instability after injury may aid in determining prognosis, leading to better treatment algorithms. In order to refine or develop treatments that are targeted toward individuals, it is important to focus on subject-specific models. Several modeling techniques exist to evaluate in vivo joint mechanics. The common techniques include image-based FEM [4–13], rigid body spring modeling/discrete element analysis (RBSM) [14–16], or SCM [17–19]. The models are either displacement driven or force driven. Generally, model geometries are acquired from modalities such as computed tomography (CT) [4–8,14,15,19] or MRI [9–11,17,18]. Kinematics are determined through external (surface markers) or internal (biplanar radiography) measures, while tendon forces are estimated from corresponding musculature electromyography (EMG) and cross-sectional area, and ground reaction forces are measured using force platforms [11,20]. These loads and displacement boundary conditions are input into the model to infer joint kinetics/kinematics and resulting surface and/or volumetric stresses and strains. FEM is the most common and accurate method to determine stresses [11,20,21]. However, depending on the complexity of the problem, the process of developing the mesh can be laborious and obtaining a converged solution can be computationally intensive [22], which limits its clinical applicability. Depending on the type of problem (for instance, deformable versus rigid), more simplified analyses can be performed based on relevant assumptions to determine appropriate solutions. This is the basis of RBSM and SCM techniques. Using these methods, joint mechanics can be evaluated in a computationally efficient manner compared to FEM [23], which makes them relevant for clinical applications. The underlying question is whether these methods are competent to provide data that are sufficiently accurate for the intended application. The ability to accurately determine joint mechanics has wide clinical implications, especially in complex joints such as the wrist. It may be possible to sufficiently evaluate changes in joint mechanics as a result of injury or surgical intervention from surface contact mechanics data alone. This can be achieved through the SCM technique, without the need for a complex volumetric analysis [24]. However, the SCM technique has not been extensively used for orthopedic applications. Computational modeling has been extensively applied to the lower extremity to evaluate in vivo joint mechanics [4–11,18]. In the wrist, studies have evaluated in vivo joint mechanics during functional activities [12,14,16,17] and have also simulated the effects of some carpal fractures and limited fusions [13,15,19]. Scapholunate (SL) ligament injury is a commonly occurring wrist ligament injury that can lead to SL joint instability and progressive degenerative changes [25–28]. Prior modeling work on the in vivo effects of SL ligament injury or surgical repair appears to be limited [29,30]. Hence, we investigated differences in radiocarpal in vivo joint mechanics obtained from SCM for normal wrists, after SL ligament injury, and after surgical repair to results from the FEM “gold standard.” We did not intend to make comparisons between the normal, injured, and postoperative states. Our goal was to show that contact outcomes obtained from SCM would be comparable to those obtained from a similar FEM analysis regardless of wrist state and to demonstrate the feasibility and applicability of the SCM technique.

One's ability to exert controlled forces on the environment, such as when manipulating fragile objects, is very important in everyday life. This suggests that force regulation is a necessary component of motor control. In robotics, an effective way to implement force control is by imposing a low contact impedance with critical damping, and using admittance control to regulate force output [1,2]. Human limbs can be modeled as second order mechanical systems, under the assumption that tendons are much stiffer than muscle fibers. The mechanical properties of muscle fibers alone render the implementation of the aforementioned direct force control strategy as not efficient. Several studies have demonstrated that the exertion of force onto the environment results in an increase in muscle stiffness [3–5] and a reduction of muscle damping to under critical values [6,7]. Modeling tendons and contractile elements independently requires higher than second order muscle-tendon models [8]. The presence of a tendon elastic element favors an oscillatory response to external disturbances that normally needs to be eliminated [9]. We demonstrated that a higher order model always exhibits an oscillatory free response and cannot be critically dampened for mechanical parameters included within the normal physiological range. This requires the force controller implemented by the central nervous system (CNS) to employ active feedback and feed-forward regulation. We propose that oscillations, whether part of an external disturbance or of the system's response, can be actively compensated for by the CNS with a position control approach, as long as a predictive model of the perturbation, and an internal model of the system's biomechanics are available. This model of control is in agreement with findings previously published by our group that showed how the implementation of an internal feed-forward model trajectory can be part of a force-regulation strategy [10].

This study presents a methodology to determine thumb and index finger kinematics while utilizing a minimal set of markers. The motion capture of skin-surface markers presents inherent challenges for the accurate and comprehensive measurement of digit kinematics. As such, it is desirable to utilize robust methods for assessing digit kinematics with fewer markers. The approach presented in this study involved coordinate system alignment, locating joint centers of rotation, and a solution model to estimate three-dimensional (3-D) digit kinematics. The solution model for each digit was based on assumptions of rigid-body interactions, specific degrees of freedom (DOFs) at each located joint, and the aligned coordinate system definitions. Techniques of inverse kinematics and optimization were applied to calculate the 3-D position and orientation of digit segments during pinching between the thumb and index finger. The 3-D joint center locations were reliably fitted with mean coefficients of variation below 5%. A parameterized form of the solution model yielded feasible solutions that met specified tolerance and convergence criteria for over 85% of the test points. The solution results were intuitive to the pinching function. The thumb was measured to be rotated about the CMC joint to bring it into opposition to the index finger and larger rotational excursions (>10 deg) were observed in flexion/extension compared to abduction/adduction and axial rotation for all joints. While the solution model produced results similar to those computed from a full marker set, the model facilitated the usage of fewer markers, which inherently lessened the effects of passive motion error and reduced the post-experimental effort required for marker processing.

In this work, a semiactive electromagnetic vibration absorber has been developed based on a proposed electromagnetic stiffness adjustable spring model, which presents a new solution for adjusting stiffness in the field of vibration absorber devices. Simulation study on the electromagnetic spring has been performed to determine the structural parameter of the semiactive vibration absorber. An experimental rig is also built up to investigate its practical vibration control effectiveness. Firstly, the finite element model of the test bench is used to analyze its vibration characteristics. Then, the vibration reduction effect is predicted through the simulation analysis, from which the optimal control positions are found. Finally, the experimental studies are also conducted, and the results show that this semiactive electromagnetic vibration absorber has a frequency adjustment range from 21 Hz to 25 Hz, in which considerable vibration reduction from 5 dB to 10 dB can be achieved.

Muscle-driven simulations of human and animal motion are widely used to complement physical experiments for studying movement dynamics. Musculotendon models are an essential component of muscle-driven simulations, yet neither the computational speed nor the biological accuracy of the simulated forces has been adequately evaluated. Here we compare the speed and accuracy of three musculotendon models: two with an elastic tendon (an equilibrium model and a damped equilibrium model) and one with a rigid tendon. Our simulation benchmarks demonstrate that the equilibrium and damped equilibrium models produce similar force profiles but have different computational speeds. At low activation, the damped equilibrium model is 29 times faster than the equilibrium model when using an explicit integrator and 3 times faster when using an implicit integrator; at high activation, the two models have similar simulation speeds. In the special case of simulating a muscle with a short tendon, the rigid-tendon model produces forces that match those generated by the elastic-tendon models, but simulates 2–54 times faster when an explicit integrator is used and 6–31 times faster when an implicit integrator is used. The equilibrium, damped equilibrium, and rigid-tendon models reproduce forces generated by maximally-activated biological muscle with mean absolute errors less than 8.9%, 8.9%, and 20.9% of the maximum isometric muscle force, respectively. When compared to forces generated by submaximally-activated biological muscle, the forces produced by the equilibrium, damped equilibrium, and rigid-tendon models have mean absolute errors less than 16.2%, 16.4%, and 18.5%, respectively. To encourage further development of musculotendon models, we provide implementations of each of these models in OpenSim version 3.1 and benchmark data online, enabling others to reproduce our results and test their models of musculotendon dynamics.

The rheological behavior of concentrated orange juice (FCOJ) has been shown to be shear-thinning in several recent studies. Concentric cylinder viscometers have been used to obtain the rheological data in these studies. The effect of temperature, soluble solids, and pulp content has been described quantitatively. To estimate the pumping power requirements of FCOJ, the mechanical energy balance equation is used together with the necessary estimates of pressure drop due to friction in pipes and fittings estimated from empirical equations. Empirical equations are available to calculate power consumption during agitation of concentrated orange juice in terms of the dimensionless groups: power and agitator Reynolds numbers for several types of agitators. Paper published with permission.

The use of compliance chambers in mock circulatory loop construction is the predominant means of simulating arterial compliance. Utilizing mock circulatory loops as bench test methods for cardiac assist technologies necessitates that they must be capable of reproducing the circulatory conditions that would exist physiologically. Of particular interest is the ability to determine instantaneous compliance of the system, and the ability to change the compliance in real-time. This capability enables continuous battery testing of conditions without stopping the flow to change the compliance chamber settings, and the simulation of dynamic changes in arterial compliance. The method tested involves the use of a compliance chamber utilizing a circular natural latex rubber membrane separating the fluid and air portions of the device. Change in system compliance is affected by the airspace pressure, which creates more reaction force at the membrane to the fluid pressure. A pressure sensor in the fluid portion of the chamber and a displacement sensor monitoring membrane center deflection allow for real-time inputs to the control algorithm. A predefined numerical model correlates the displacement sensor data to the volume displacement of the membrane. The control algorithm involves a tuned π loop maintaining the volume distention of the membrane via regulation of the air space pressure. The proportional integral (PI) controller tuning was achieved by creating a computational model of the compliance chamber using Simulink™ Simscape® toolboxes. These toolboxes were used to construct a model of the hydraulic, mechanical, and pneumatic elements in the physical design. Parameter Estimation™ tools and Design Optimization™ methods were employed to determine unknown physical parameters in the system, and tune the process controller used to maintain the compliance setting. It was found that the resulting control architecture was capable of maintaining compliance along a pressure-volume curve and allowed for changes to the compliance set point curve without stopping the pulsatile flow.

Lamellar atomically-thin sheets such as graphene (and its bulk equivalent graphite) and molybdenum disulfide have emerged as excellent solid lubricants at the macro scale and show great promise as protective coatings for nanoscopic applications. In this study, the failure mechanisms of graphene under sliding are examined using atomistic simulations. An atomic tip is slid over a graphene membrane that is adhered to a semi-infinite substrate. The impact of sliding velocity and substrate rigidity on the wear and frictional behavior of graphene is studied. In addition, the interplay of adhesive and abrasive wear on the graphene coating is also examined. The preliminary results indicate that graphene has excellent potential as a nanoscale due to its atomically-thin configuration and high load carrying capacity.Copyright © 2012 by ASME

The concern with Fitness-For-Service (FFS) assessment using stochastic analysis for aged pressure equipments with local metal loss has been growing for the last several years. The structural integrity assessment based on reliability helps to make a decision as to whether to run or repair the equipments with local metal loss. As for analysis of failure probability, it is important to clear which variables affect highly the structural integrity. The stochastic property of the influential parameter needs to be clarified. There has, however, been little study to analyze quantitatively the sensitivity of the parameters for the FFS assessment of the components with local metal loss. In this study, the effects of parameters on plastic collapse of the damaged component were evaluated utilizing parameter sensitivity study. Additionally, sensitivity indices for the component with several shapes of local metal loss were analyzed. It was found from the results that the corrosion rate has much influence on probability of failure. Finally, practical stochastic analysis procedure for the component with local metal loss was proposed. In the proposed procedure, the parameter which has consistently low sensitivity to limit state was used as constant value.

Most Citrus Concentrate Plants with operating Feed Mills in production today incorporate standard single pass, 180° furnace configuration, parallel flow, direct-fired pulp dryers with either natural gas, or fuel oil fired burners. Paper published with permission.

One of the main limiting factors when a green field pulp mill intends to increase its production is the capacity of the Tomlinson boiler by which the cooking chemicals are recovered. Since a boiler of this kind has a service life of some thirty years and represents a substantial investment, it is not an easy decision to replace it for a minor production increase. This study takes a novel approach to the problem. The excess black liquor is assumed to be recovered in a black liquor gasifier, an emerging technology for alternative black liquor recovery. Black liquor gasification in itself has been studied considerably during the last decade. In this study it is combined with the gasification of biomass, i.e. bark and wood, which is already available at a pulp mill. The resulting hybrid energy system, with a gas turbine and a gas expander, offers interesting possibilities: good off-design performance and high efficiency with respect to the fuel quality.Copyright © 1998 by ASME

On rare occasions, a portion of an uncut fiber will exit the discharge chute of a consumer hammer mill type chipper/shredder and remain at rest with its inboard portion in the neighborhood of the rotating elements. Disturbing the fiber may cause it to commit to the rotating flails and be pulled instantaneously back into the machine. A number of investigators have postulated that an operator who grasps a fiber that subsequently experiences this pull-in phenomenon cannot release it fast enough to avoid being dragged into the flails. This hypothesis is discredited by both analytical and experimental analyses.

Limited quantities of dried juice sacs have been produced commercially in Florida since the late 1950’s. Several citrus processors have been involved in this production at one time or another and one well known processor is currently producing relatively small but significant quantities. Workers at the University of Florida’s Agricultural Research and Education Center at Lake Alfred, as well as at the USDA’s Utilization Research Labs at Winter Haven, Florida and Pasadena, California have been advocating this speciality by-product citing the tangible advantages of the higher return as compared to that of dried orange pulp for animal feed. At the same time they point out the intangible benefits of removing one of the major sources of air pollutants from the stack emissions of feed mills. Paper published with permission.

The use of pulp wash as an aid in the production of citrus juice has gained acceptance since 1957. Earlier use is known, but real recognition seemed to await a certain period in the development of frozen orange juice concentrate, and a freeze. The history of this product could be divided into three time periods each approximately equal. The first period of time was certainly formative in which the product enjoyed all of the advantages of novelty. The second period of time was characterized by increasing competition and need for lowering costs. This required that the plants measure the fruit in terms of pounds of soluble solids and that they recover as product all that could be had without an unquestionable damage to quality. The demand for more recovery of the soluble solids exceeded the capability of any mechanical finishing equipment to distinguish between the juice left on a quite dry pulp and the pulp, which still had good juice on it. This brought about fresh thinking and new processing ideas, including one of gently rinsing the juice from a wet pulp. This became known as “Pulp Wash” and was developed during the third period of time. Paper published with permission.

The Citrus Processing industry has come a long way in the last twenty years. In some respects the handling of plant wastes may be said to have kept pace with this growth. Two decades ago, the only by-product was peel oil. Peelings and pulp were hauled away to groves or other suitable locations by crude forerunners of modern dump trucks. The more remote this location was the better since the odor could be terrific. Any suitable lake or city sewer or underground well was used for liquid wastes. Paper published with permission.

The importance of this development to the citrus industry need not be further discussed as all of you are well aware of financial advantage possible through pulp washing. Paper published with permission.

Pelleting of complete formula feeds in this country started in the early 1930’s. Today, it is estimated that over thirty million tons are pelleted annually. Pelleting of single ingredients, such as citrus fines, alfalfa meal, wheat by-products, and sugar beet pulp, received their impetus in the early 1950’s. Today, it appears that large quantities of citrus pulp will be pelleted for the domestic and foreign markets. Paper published with permission.

Processors of citrus fruit are faced with disposal of the pulp left over after juice is extracted from the fruit. Generally, the pulp is dried in steam or oil fired dryers and then sold as cattle feed. If disposal of the pulp is the prime factor of interest to the operator; shredding and hot air drying is sufficient. For more efficient removal of water from the pulp and the obtainment of other by-products, mainly citrus molasses and stripper oil, consideration should be given to the installation of presses and a molasses evaporator. Most authorities will agree that water can be evaporated more efficiently in a multiple effect evaporator than in a hot air dryer. Presses and an evaporator represent considerable investment, therefore the decision to install a Molasses Plant must be weighed carefully, balancing potential savings against the installed cost. Paper published with permission.

Automated control is an old story in the concentrate industry and is typified by the normal evaporator control systems, brix blenders, etc. that are installed in all of the concentrate plants. The phase of automation to be discussed here concerns the control of the rate of oranges being conveyed from the storage bins to and through the juicing operation. The purpose of this control system is to allow the extraction, finishing and pulp wash processes to take place at continuous uniform rates in direct and continued relationship to evaporator requirements. Paper published with permission.

Bulk storage of dried citrus pulp at Plymouth was first considered because our customers, many of whom have been buying our pulp for 15 years, were adopting feeding systems which fitted bulk feeds, and because bag and bag dumping costs seemed to provide a source for sizeable savings. Paper published with permission.

Beginning in August 2013, Anadarko Petroleum formed the “20A Project Initiative” for qualifying 20 ksi equipment for a Deepwater Gulf of Mexico (GoM) development. This paper will cover the systems approach used for the qualification (verification, validation and quality) of a system of components, including sub-assemblies and assemblies that are required for a 20 ksi development. The systems approach begins with the framework and management of this framework inside the overall development process. The systems approach categorizes each component by mode of operation (many pieces of equipment are used in multiple operational modes). These modes of operation are Drilling, Completions, Production and Intervention, and are the engineering systems used to manage the qualification of over 200 components to industry standards and U.S. government requirements. The functional requirements for each component are defined and vendors selected. Each component is then stewarded through a project-management process for design, verification, validation and quality. This process culminates with the integration of these components back into a system that can be qualified for use in an HPHT environment. This paper addresses the submittal to regulatory authority for approval to use the newly developed and qualified 20 ksi equipment for a deepwater GoM development. This project ends in 2019. This six-year development journey presented challenges and achieved breakthrough technologies for the industry. This journey, its organizational approach using systems engineering techniques and integration processes are presented.

The growing interest in citrus pulp, or frozen, stabilized juice sacs, stems from the rapid influx of high quality citrus juices and juice added beverages into the market. Juice sacs have been recovered for many years and it has not been until the past few years that this practice evolved into a sophisticated technology. Paper published with permission.

In most large citrus processing plants world-wide, the peel is made into cattle feed. The peel is shredded, mixed with lime, allowed to react, and pressed. The liquid from the pressing is evaporated and recycled into the peel or sold as molasses. The press cake is dried in single pass, direct fired rotary dryers with co-current flow of heating gasses and product. Paper published with permission.

One of the most perplexing problems that confronts the designer of citrus processing machinery and equipment is that of corrosion resistance. Citrus waste product, pulp, and juice have a citric acid content of around 2.7% by weight which will quickly destroy paint or lacquer finishes and will rapidly corrode carbon or low alloy steels. Only the highly alloyed chromium nickel steels, monel, inconel, pure nickel, some of the bronzes, tin and copper can withstand the corrosive attack of citrus juice and pulp. Paper published with permission.

Dried citrus pulp is an important by-product of the citrus processing industry. It is a bulky, granular, carbohydrate concentrate livestock feed produced by drying the peel, seed, and rag refuse of citrus fruit. Approximately 324,159 tons of citrus pulp were produced in 1964–65 (2). This amount will probably increase by more than 60 percent during the next 10 years, since the orange crop is expected to increase from the 1964–65 estimate of 83,000,000 boxes to 183,000,000 by 1975 with 80 percent of the oranges being processed (7). The 1975 grapefruit crop is expected to be 30,000,000 boxes with over one-half being processed. These increases in citrus production could mean that by 1975 over 650,000 tons of dried pulp would be produced in the State. Paper published with permission.