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Hip joint contact loads in older adults during recovery from forward loss of balance by stepping.

Hip joint contact loads in older adults during recovery from forward loss of balance by stepping.

93 The purposes of this study were to 1 determine the effect of balance perturbation intensity 94 on peak hip contact loads during balance recovery using the single step balance recovery[r]

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Three-dimensional chiropractor-patient contact loads during side posture lumbar spinal manipulation: a pilot study

Three-dimensional chiropractor-patient contact loads during side posture lumbar spinal manipulation: a pilot study

Background: Patients with low back pain often seek chiropractic care and more than ninety percent of Chiropractors use lumbar side posture manipulation for the treatment of low back pain. During this procedure chiropractors deliver forces by means of hand contact on the patient in a side lying position. The objective of this pilot study was to report on the three-dimensional forces at the hand contact between the chiropractor and the simulated patient (asymptomatic volunteers) during side posture lumbar high velocity low amplitude adjustments. Methods: In 2005, two licensed chiropractors delivered spinal manipulations to the lumbar spines of the
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Dry Friction and Wear Behavior of Forged Co  29Cr  6Mo Alloy without Ni and C Additions for Implant Applications

Dry Friction and Wear Behavior of Forged Co 29Cr 6Mo Alloy without Ni and C Additions for Implant Applications

(4) From a consideration based on the Hertzian contact theory, it is found that the forged alloy elastically contacts an alumina ball over the entire contact loads tested, resulting in the stress distribution causing mild adhesive wear on the frictional surface. Estimating the contribution of the abrasive wear (the area fraction of the abrasive scars) on the basis of the observation of the wear scar, the calculation of the whole wear factor results in that of the 10 8 mm 2 /N order. The calculate value is correspond to the order of the measured wear factor. Hence, the dominant wear mechanism is mild adhesive wear, though the extrinsic abrasive wear mediated by the wear debris likely coexists.
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Tribological investigation for next generation polymeric micro systems

Tribological investigation for next generation polymeric micro systems

Traditional studies in tribology have typically been performed at load and length scales compatible with the macroscopic devices being designed and studied. These largely empirical studies are often unsatisfactory in the present context because they operate in mechanical regimes very different to the dynamics of MEMS and other small mechanisms, and they lack quantitative analysis based on fundamental atomic-scale phenomena. Commercial atomic force microscopy (AFM), scanning force microscope (SFM) and various custom-built or commercially available micro-tribometers have been expanded and improved since 1996 to examine tribological behavior at the atomic-scale that involved in friction, wear, lubrication and the interaction of contacting surface (Singer, 1992). However, conventional tribological testers, such as pin/ball-on-disk equipment, are not suitable for evaluating tribological properties of materials used in MEMS applications as the contact areas involved in these devices are only a few hundreds of nm 2 and the contact loads are in the μN or mN range. There is a significant gap between the parameter ranges accessible to these different scales of instruments and more traditional tribology test tools (see figure 2.14) (Dvorak, 1998).
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Mechanisms of antiwear tribofilm growth revealed in situ by single-asperity sliding contacts

Mechanisms of antiwear tribofilm growth revealed in situ by single-asperity sliding contacts

macroscopic, multi-asperity contacts (specific asperity contact areas and pressures thus being unknown) that are then analyzed post mortem and ex situ, often after extracting the sample from base stock, potentially altering the tribofilm (20). Although macroscopic in situ studies of zinc polyphosphates under static compression (21, 22) have shown irreversible loss of crystallinity and little increase in polymerization with increased pressure, these studies do not involve dynamic sliding. In situ single-asperity sliding studies have the advantage that contact loads and geometries can be controlled and quantified, local tribofilm properties such as morphological evolution with nanometer resolution, tribofilm volume, friction, adhesion and wear measured concurrently, and results compared with atomistic simulations (8).
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Effect of frictional treatment on the microstructure and surface properties of low-carbon steel

Effect of frictional treatment on the microstructure and surface properties of low-carbon steel

176 GPa under a load of 25 gf and from 204 to 155 GPa under a load of 200 gf. It is for the first time that the effect of a decrease in the elastic modulus is observed for a carbon steel subjected to frictional treatment. It also follows from the microindentation data that frictional treatment increases the capability of the surface of annealed low-carbon (0.17 wt% C) steel to withstand higher contact loads prior to plastic deformation.

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City of Lincoln, Nebraska STEVENS CREEK BASIN TRUNK SEWER TECHNICAL MEMORANDUM NO. 5 PIPE MATERIAL SELECTION TABLE OF CONTENTS

City of Lincoln, Nebraska STEVENS CREEK BASIN TRUNK SEWER TECHNICAL MEMORANDUM NO. 5 PIPE MATERIAL SELECTION TABLE OF CONTENTS

The use of RCP for conveyance of raw sewage has been an industry standard for more than seven decades. RCP is manufactured in several facilities nationwide, several of which are in close proximity to Lincoln. RCP has enjoyed such a following due to its inherent strength, relatively low cost when compared to other products, and lack of ferrous materials in contact with conveyed wastewaters. Originally issued as a tongue and groove joint buttered with mortar, the pipe can now be made in several joint configurations and lined with PVC and other materials. The pipe can be designed to a specific design load termed “D-load pipe,” or can be designed on the basis of allowable stresses resulting from bending and shear. The pipeline specifier must choose the best approach to suit the anticipated design conditions.
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Numerical analysis of bovine trabecular bone by using physiological loads specific to normal walking loads and down stairs loads

Numerical analysis of bovine trabecular bone by using physiological loads specific to normal walking loads and down stairs loads

Second scope of this project is to perform static analysis by using FE package. Nowadays, numerical approaches seem to be very imperative in initial or preliminary study. That due to precision of numerical simulation brings draft taught of the simulation problem. In addition of that, stage of numerical study is far cheaper than constructing or setting apparatus for real experiment. Not repudiate on the experiment work, instance of that, hand-on experimental work is the real situation under a very minimal engineering assumption or constraint. Differently approaches on finite element simulation, the software is tends to excludes any external environment contact to the simulation models. That limitation concludes numerical simulation is just a tool to get a general problem solution near to the real situation.
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Wear and frictional behaviour of metals

Wear and frictional behaviour of metals

The frictional force was recorded during the sliding process for all the materials. Coefficient of friction verses the sliding distances is displayed in Fig. 3 for all the materials under different applied loads. The frictional behaviour for all the materials seems to be steady especially with the brass and the mild steel. Aluminium shows a bit of fluctuation in the value which represents a modification on the surface occurring during the sliding such behaviour was noticed when the materials transfer from surface to another and detachments may occurs leading to the fluctuation in the frication coefficient. This has been reported by [11, 12] when different materials have been tested under dry adhesive wear loadings. With regards of the influence of the applied load on the frictional behaviour of the materials, increase the applied load reduces the friction coefficient especially for the brass and the aluminium materials. Mild steel shows no effect of the applied load on its frictional behaviour. Comparing the three materials, brass exhibits the lowest frication coefficient among others. This is clearly shown in the summarized frictional results in Fig. 3. The differences in the wear and the frictional behaviour of those materials are due to the interaction between the surfaces during the sliding. The roughness of the surfaces may assist in clarifying this.
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Effect of Staircase on a Structure Subjected to Seismic Forces

Effect of Staircase on a Structure Subjected to Seismic Forces

An earthquake is a spontaneous event and behaves quite differently. The force generated by the seismic action of an earthquake is different than other types of loads, such as gravity and wind loads. It strikes the weakest spot in the whole three dimensional building. Ignorance in design and poor quality of construction results many weaknesses in the structure, thus causes serious damage to life and property. Staircase is the part of secondary system of the structures and it is one of the essential part of building because of its functional importance. From geometrical point of view, a stair is composed by inclined elements (beams and slabs) and by short (squat) columns.
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Avian Influenza H7N9/13 and H7N7/13: a Comparative Virulence Study in Chickens, Pigeons, and Ferrets

Avian Influenza H7N9/13 and H7N7/13: a Comparative Virulence Study in Chickens, Pigeons, and Ferrets

Interestingly, the results of a mouse infection study indicate that the human H7N9 isolates replicated more efficiently and were more lethal than the H7N9 viruses of direct avian origin (8). They also tested two H7N9 viruses isolated from birds and three H7N9 strains isolated from humans in the ferret model and showed that all of the viruses replicated to similar levels in the nasal turbinates but that the viral loads in the tonsils, tracheas, and lungs were larger in ferrets infected with the human isolates, which were also able to rep- licate in the brain. Importantly, that group also reported respiratory droplet transmission between ferrets infected with H7N9 viruses iso- lated from humans, indicating the potential for human-to-human transmission of these viruses (8). In contrast, Belser and coworkers found no evidence of efficient droplet-mediated transmission be- tween ferrets (34), and therefore, experimental conditions or strain variations might also influence transmission. In another study, Zhu and coworkers used the ferret model to evaluate the infectivity and transmissibility of another avian H7N9 virus isolated from a human, A/Shanghai/2/13, and found that the virus replicated in the upper and
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1.
													Power electronics based energy management system with storage

1. Power electronics based energy management system with storage

Energy savings and energy efficiency have become top priorities all around the world, stimulated by the Kyoto protocol and other pressing needs to reduce fossil fuel consumption [1]. Additionally, energy security is a necessity for many installations such as military bases and health care facilities where reducing energy consumption must be accomplished while keeping critical electrical loads serviced at all times. In this paper, A Power-electronics-based energy management system (EMS) is presented to accomplish peak power control in a single-phase power system while guaranteeing continuous service to critical loads at the same time. Peak power control, also known as peak shaving [2], is a method used to reduce the electricity charges for users with time of use (TOU) contracts and those who pay for the demand charges [1]. The power system does not need to be a micro-grid, meaning that distributed generation (DG) does not need to be part of the power system [4].
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Structural Analysis and Design of Commercial Building for Earthquake Resistance by Using SAP2000

Structural Analysis and Design of Commercial Building for Earthquake Resistance by Using SAP2000

Lateral load acting in the building is earthquake/seismic load and wind load. Earthquake load is determined by calculating lumped mass at floor level and horizontal base shear (IS 1893). It was done by Seismic Coefficient Method. Wind load (IS 875 Part 3) is obtained by design wind speed and design wind pressure. Earthquake load being the pre- dominant one between the two lateral loads, hence its effect was only considered. For the analysis of earthquake load, following methods is generally carriedout:

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Analysis of G+5 Multistored Building

Analysis of G+5 Multistored Building

ABSTRACT: The design process of structural planning and design requires not only imagination andconceptual thinking but also sound knowledge of science of structural engineering besides the knowledge of practical aspects, such as recent design codes, bye laws, backed up by ample experience, intuition and judgment. The purpose of standards is to ensure and enhance the safety, keeping careful balance between economy and safety. In the present study G+6 building at Ananthapuramu is designed (Slabs, Beams, Columns and Footings) using Auto CAD software. In order to design them, it is important to first obtain the plan of the particular building that is, positioning of the particular rooms (Drawing room, bed room, kitchen toilet etc.) such that they serve their respective purpose and also suiting to the requirement and comfort of the inhabitants. Thereby depending on the suitability; plan layout of beams and the position of columns are fixed. Thereafter, the loads are calculated namely the dead loads, which depend on the unit weight of the materials used (concrete, brick) and the live loads, which according to the code IS:456-2000 and HYSD BARS FE415 as per IS:1786-1985. Safe bearing capacity of soil is adopted as 350KN/M 2 at a depth of 6ft and same soil should extent 1.5 times the width of footing below the base of footing. Footings are designed based on the safe bearing capacity of soil. For designing of columns and beams, it is necessary to know the moments they are subjected to. For this purpose, frame analysis is done by limit state method. Designing of slabs depends upon whether it is a one - way or a two way slab, the end conditions and the loading. From the slabs, the loads are transferred to the beam. Thereafter, the loads (mainly shear) from the beams are taken by the columns. Finally, the sections must be checked for all the four components with regard to strength and serviceability.
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Simulation of District Cooling Plant and Efficient Energy Air Cooled Condensers (Part I)

Simulation of District Cooling Plant and Efficient Energy Air Cooled Condensers (Part I)

A large-scale of district cooling plant could save energy consumption costs from 25% to 40% as compared with the sum of conventional centralized air- conditioning system of each building. In addition to a better energy efficiency, there are other environmental and planning benefits such as, reduced water consumption, reduced carbon footprint, minimized noise and vibration impact, flexibility in building design, saving in plant room space, reduced operating re- dundancy and enhanced system reliability [3] [4]. District cooling plant supplies cooling services at the temperature level of 5˚C - 7˚C, while with an expected return temperature of 12˚C - 15˚C. The central cooling plant is mostly assisted with a cold thermal storage unit, which allows the leveling of the cooling loads in the network during the day or season and creates a match in supply and demand of cooling services [5] [6]. Thus, a district cooling network with 8˚C and 15˚C as the supply-return temperature should be an ideal one. Positive to this configura- tion is lower energy loss and higher system efficiency. The energy use in a large district cooling plant before and after the addition of stratified chilled-water sto- rage has been conducted and the average efficiency of the system improved by more than 10% [7].
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Robotic Collision Sensor and/ Axial Compliance Device Protector

Robotic Collision Sensor and/ Axial Compliance Device Protector

High Repeatability: Following a collision, the use of precise locating components enables the Protector to reset to within 0.001 inches of its original position. Generous Range of Motion: During a crash the Protector can comply large distances in response to any type of crash (angular, axial or torsional) thus allowing the robot controller ample time to take corrective action. Rugged Design for Axial Compliance: The rugged design and construction of the Protector, with generous use of hardened tool steel in contact and wear areas, allows the unit to be used as an Axial Compliance Device for end-effectors. The unit can also provide angular and torsional compliance for certain applications.
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Structural Evaluation of Drop Load Effects on Buried Structures

Structural Evaluation of Drop Load Effects on Buried Structures

In this approach, stress wave propagation, contact-impact phenomena arising from accidental dropping of components during the steam generator replacement operations, energy dissipation through yielding of steel reinforcement, concrete cracking, and damping of stress waves in the soil media are modelled The results of drop load analysis (structural deflections, bending moments, and axial forces) are then used for to structural evaluation considering serviceability, damage, and failure limit states.

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Identification of Power Electronics Controlled Loads in Distribution Power System Using 10 Complex MUSIC Technique

Identification of Power Electronics Controlled Loads in Distribution Power System Using 10 Complex MUSIC Technique

With an increasing amount of measurement data, automating power quality characterization and classification of disturbances is desirable. This will require combined effort and knowledge from both electrical power systems and signal processing. A digital signal processor is a specialized microprocessor designed specifically for digital signal processing, generally used in real-time computing. DSP algorithms require a large number of mathematical operations to be performed quickly on a set of data. The digital signal processor can be programmed to perform a variety of signal processing operations, such as filtering, spectrum estimation, and other DSP algorithms [3]. There are so many techniques to perform the DSP operation. Here the MUSIC technique to identify the loads has been considered. The MUSIC method employs a harmonic model and estimates the frequencies and powers of the harmonics in the signal. The MUSIC algorithm is a noise subspace based method. MUSIC detects signal frequencies by performing an eigen decomposition on the data vector covariance matrix from received signal samples.
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A COMPARISON OF SASSI2010 and SAP2000 FIXED-BASE ANALYSIS RESULTS FOR VALIDATION OF A LARGE SCALE NUCLEAR REACTOR BUILDING MODEL

A COMPARISON OF SASSI2010 and SAP2000 FIXED-BASE ANALYSIS RESULTS FOR VALIDATION OF A LARGE SCALE NUCLEAR REACTOR BUILDING MODEL

Two analysis models were created to consider the conditions of cracked and uncracked concrete behavior. However, only uncracked results are presented herein. Uncracked case uses full bending properties for concrete walls and slabs, whereas, the cracked case uses half of the bending properties for the concrete walls and slabs and higher damping. The geometry and applied loads for two models are identical except the assigned concrete properties and damping. For the cracked model, the out-of-plane stiffness is considered cracked for roof, walls, and all floor slabs other than the base. The sectional properties of the out-of-plane stiffness of the cracked elements are reduced to half. The in-plane stiffnesses remain unchanged. The fixed-base model has restrained nodes at the foundation. The RXB was supported on over 2000 zero-length rigid spring elements at the bottom of the foundation. The analysis and design methods used in the development of the SAP2000 analysis model are consistent with the ASCE Standard 4 and the ASCE/SEI 43-05.
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Microgrid Development Using a Grid Tie Inverter

Microgrid Development Using a Grid Tie Inverter

The measurement results of GTI output voltage are shown in Figure 7. The GTI output was in accordance with the gridvoltage output. Measurements of power power were performed on the inverter, load, and line outputs to thegrid. Measurement began by activating the GTI without being connected to thegrid, it marked by value of grid = 0 W power, as shown in Table 4. Test results using the local loads and microgrid configuration, From 170 W power required by loads, is only 14 W loads power supplied from the grid, it indicates that, using a microgrid configuration electrical power requirements to the loads which should have been supplied from the grid, can be reduced up to 91%.
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