Amount Of Slippage Research Articles

Mapping vision loss of patients in a glaucoma backlog following the COVID-19 pandemic: a real-world analysis using the Glauc-Strat-Fast risk stratification tool.

Glauc-Strat-Fast is a clinical tool recommended by The Royal College of Ophthalmologists to classify glaucoma patients into strata of risk for significant future sight loss and an estimate of resource requirement. The aim of this study was to map the movement of glaucoma patients across stratification boundaries on Glauc-Strat-Fast during the COVID-19 pandemic. Glauc-Strat-Fast was applied to a consecutive sample of 100 primary open angle glaucoma patients in a backlog at Worcestershire Acute Hospitals NHS Trust. Stratification outcomes were compared between clinic visits prior to the COVID-19 pandemic versus the follow-up visit. Patients were stratified twice separately based on their worse eye (i.e., most affected) and better eye (i.e., least affected) according to Glauc-Strat-Fast. Amount of slippage (difference between target follow-up and actual follow-up) ranged from 2 to 32 months. There was a statistically significant average reduction in visual field mean deviation for better and worse eyes between visits (p = <0.001). At follow-up, no worse eyes were classified as being low risk (green), while 96 were classified as high risk (red). For better eyes, elevation of risk into the highest strata of Glauc-Strat-Fast observed a three-fold increase in patients (19 versus 56) between visits. This retrospective real-world analysis highlights patients' movement into the highest strata on the Glauc-Strat-Fast tool and demonstrates a significant deterioration in visual outcomes during a period of extensive appointment slippage. The findings demonstrate the utility of Glauc-Strat-Fast as a tool for improved patient management.

ADOLESCENT IDIOPATHIC SCOLIOSIS WITH CONCOMITANT SPONDYLOLYSIS: CHOICE OF FUSION LEVELS EVALUATION OF THE OUTCOMES OBTAINED LEAVING THE LYTIC LEVEL NOT INSTRUMENTED

7% of adolescent idiopathic scoliosis (AIS) patients also present with a pars defect. To date, there are no available data on the results of fusion ending proximal to a spondylolysis in the setting of AIS. The aim of this study was to analyze the outcomes of posterior spinal fusion (PSF) in this patient cohort, to investigate if maintaining the lytic segment unfused represents a safe option.Retrospective review of all patients who received PSF for AIS, presented with a spondylolysis or spondylolisthesis and had a min. 2-years follow-up. Demographic data, instrumented levels and preoperative radiographic data were collected. Mechanical complications, coronal or sagittal parameters, amount of slippage and pain levels were evaluated.Data from 22 patients were available (age 14.4 ± 2.5 years), 18 Lenke 1–2 and four Lenke 3–6. Five patients (24%) had an isthmic spondylolisthesis, all Meyerding I. The mean preoperative Cobb angle of the instrumented curves was 58 ± 13°. For 18 patients the lowest instrumented vertebra (LIV) was the last touched vertebra (LTV); for two LIV was distal to the LTV; for two, LIV was one level proximal to the LTV. The number of segments between the LIV and the lytic vertebra ranged from 1 to 6. At the last follow-up, no complications were observed. The residual curve below the instrumentation measured 8.5 ± 6.4°, the lordosis below the instrumented levels was 51.4 ± 13°. The magnitude of the isthmic spondylolisthesis remained constant for all included patients. Three patients reported minimal occasional low back pain.The LTV can be safely used as LIV when performing PSF for the management of AIS in patients with L5 spondylolysis

Adolescent idiopathic scoliosis with concomitant spondylolysis: choice of fusion levels and evaluation of the outcomes obtained leaving the lytic level not instrumented

Purpose7% of adolescent idiopathic scoliosis (AIS) patients also present with a pars defect. To date, there are no available data on the results of fusion ending proximal to a spondylolysis in the setting of AIS. The aim of this study was to analyze the outcomes of posterior spinal fusion (PSF) in this patient cohort, to investigate if maintaining the lytic segment unfused represents a safe option.MethodsRetrospective review of all patients who received PSF for AIS, presented with a spondylolysis or spondylolisthesis and had a min. 2-year follow-up. Demographic data, instrumented levels, and preoperative radiographic data were collected. Mechanical complications, coronal or sagittal parameters, amount of slippage, and pain levels were evaluated.ResultsData from 22 patients were available (age 14.4 ± 2.5 years), 18 Lenke 1–2 and 4 Lenke 3–6. 5 patients (24%) had an isthmic spondylolisthesis, all Meyerding I. The mean preoperative Cobb angle of the instrumented curves was 58 ± 13°. For 18 patients, the lowest instrumented vertebra (LIV) was the last touched vertebra (LTV); for 2, LIV was distal to the LTV; for 2, LIV was one level proximal to the LTV. The number of segments between the LIV and the lytic vertebra ranged from 1 to 6. At the last follow-up, no complications were observed. The residual curve below the instrumentation measured 8.5 ± 6.4°, the lordosis below the instrumented levels was 51.4 ± 13°. The magnitude of the isthmic spondylolisthesis remained constant for all included patients. Three patients reported minimal occasional low back pain.ConclusionThe LTV can be safely used as LIV when performing PSF for the management of AIS in patients with L5 spondylolysis.

Design and Performance Evaluation of Protective Clothing for Emergency Rescue

Abstract Protective clothing is very important to guarantee the safety of emergency rescuers. And proper construction design of clothing will improve the rescue efficacy. This study developed a new set of emergency rescue protective clothing (NC) and evaluated its performance. Clothing fit test, freedom of movement, and rationality of pocket tests were conducted. The results showed that the amount of slippage at the hem, waist of pants, and leg opening of NC has been greatly reduced. The NC had provided better cloth fit and dynamic comfort. The storage capacity of the pockets had been increased, the position and angle design of the pocket made it easier to take and keep the rescue tools.

A novel double slip loads friction damper to control the seismic response of structures

In this study, the performance of a proposed friction damper with two slip loads in controlling the seismic response of steel moment resisting buildings structures under moderate and intense earthquake excitations is investigated. The proposed friction damper initially operates with a smaller slip load and could shift to the higher slip load after a certain amount of slippage when subjected to intense ground motions. In this regard, the hysteresis behavior of the proposed double slip loads (DSL) friction damper is modeled and after necessary verifications is imported to the material library of OpenSees software to be used for parametric study. To evaluate the performance of the proposed DSL damper, three steel moment resisting frame (SMRF) models with 4, 8 and 14 stories are considered that are designed according to the AISC-LRFD and ASCE7-16 codes. Using a suite of earthquake records, nonlinear time history analyses (N-THA) are carried out to determine the optimal slip loads as well as the optimal amount of the slippage in between to minimize the seismic response of the considered models. The smaller slip load is optimally determined by performing N-THA on the structural models equipped with a single slip load friction damper using the earthquake records that are scaled to the design basis earthquake (DBE) level. Then, utilizing the obtained first slip load, N-THA are repeated for the models equipped with DSL friction dampers using the same earthquake records that are now scaled to the maximum credible earthquake (MCE) level to optimally determine the second slip load as well as the amount of the slippage between two slip loads. The genetic algorithm is employed to find the optimal slip loads and the amount of slippage in between. Two scenarios for height-wise variation of the DSL parameters, i.e, the slip loads and the extent of slippage, of the SMRF models are considered. In the first scenario as a practical approach, an upward decreasing pattern of slip loads along the height of the buildings is considered. In second scenario a simple search is performed to optimally identify those parameters for all floors. Furthermore, the performance of the structural models with DSL dampers are compared with those equipped with conventional single slip load systems. The results clearly demonstrate the efficiency of the proposed DSL dampers in effectively reducing the seismic response of the structures in terms of story drifts, residual drifts, absolute floor accelerations, and base shear forces in comparison to the conventional single slip load friction dampers.

Spinal sagittal alignment and trapezoidal deformity in patients with degenerative cervical spondylolisthesis

Degenerative cervical spondylolisthesis (DCS) is a cervical deformity arising from regressive changes where trapezoidal deformity characterized by hypertrophic osteophytes of spinal elements is often observed. There is a paucity of literature about the spinal contour of DCS and trapezoidal vertebrae. We conducted this research to clarify the relationship between spinal sagittal alignment and trapezoidal deformity in DCS. Total seventy-nine patients with cervical spondylosis were enrolled. Twenty-four patients who exhibited cervical spondylolisthesis were classified into DCS group. Other patients were classified into a control group. Measurements of radiographic parameters and trapezoidal deformity were made. DCS was found mostly in C3-C4 and C4-C5 (16 and 10 cases, respectively). T1S and T1-T4 TK was larger in the DCS group than in the control (T1S: 29.9 ± 2.3° vs. 23.7 ± 1.5°, T1-T4 TK: 14.9 ± 2.1° vs. 9.0 ± 1.4°). C2-C7A was smaller in DCS (3.5 ± 3.6° vs. 11.9 ± 2.3°). Trapezoidal deformity was apparent in the vertebra below the slipped segment. Among sagittal parameters, T1S and T1-T4 TK were positively correlated with DCS (r = 0.523 and r = 0.438, respectively). For these correlations with DCS, both logistic and linear regression models predicted threshold values of approximately 30° for T1S and 15° for T1-T4 TK responsible for DCS. DCS was mostly found in the middle cervical region. Among sagittal parameters, enlarged T1S and T1-T4 TK, which were strongly correlated with amount of slippage, was considered affected to DCS. Cervical kyphosis and trapezoidal deformity also exhibited strong correlations with DCS, and were considered responsible for clinical instability.

Slip flow through microchannels with lubricant-infused bi-dimensional textured surfaces

Lubricant-infused textured surfaces, where a secondary liquid impregnates textures, have been employed as an alternative to gas-cushioned textured surfaces. However, the drag reduction capabilities of this new class of textured surfaces in the laminar regime have not been explored. In this work, a pressure-driven flow through microchannels containing lubricant-infused bi-dimensional textures was numerically investigated to assess their slippage properties. A large parameter ranges, Reynolds numbers 1–1000; viscosity ratio 0–1; constriction ratio 0.1–10; lubricant fraction 0–1, were employed in the simulations. Upon balancing the velocity continuity and shear stress at the liquid–lubricant interface, we could capture the viscous effects of lubricant on the amount of slippage. The effective slip length was computed as a function of relevant non-dimensional flow and geometrical parameters for texture configurations such as posts and holes. A significant amount of dissipation in the lubricant phase was observed for a viscosity ratio greater than 0.1 for both the texture configurations investigated. However, an increased viscosity ratio between the lubricant and liquid bettered the performance of the posts compared to holes at low-lubricant fractions. The inertial effects on the effective slip length were alleviated with an increase in viscosity of the underlying lubricant, for a surface covered with holes compared to posts. Furthermore, it was shown that the validity of scaling laws for the effective slip length from the gas-cushioned textured surfaces to liquid-infused textured surfaces could be extended upon incorporating the effects of inertia and viscosity ratio. The results presented here will help in designing efficient lubricant-infused textured surfaces for drag reduction both in internal and external flow settings.

Association of Lumbar Spondylolisthesis With Low Back Pain and Symptomatic Lumbar Spinal Stenosis in a Population-based Cohort: The Wakayama Spine Study.

Cross-sectional study. To determine the association between lumbar spondylolisthesis and low back pain and symptomatic lumbar spinal stenosis (LSS) in a population-based cohort. The basic epidemiology of lumbar spondylolisthesis is not well known. There is little information regarding the association between lumbar spondylolisthesis and clinical symptoms such as low back pain and LSS symptoms. This cross-sectional study included data from 938 participants (308 males, 630 females; mean age, 67.3 years; range, 40-93 years). Lumbar spondylolisthesis was defined as a slip of ≥5%. Diagnostic criteria for symptomatic LSS required the presence of both leg symptoms and radiographic LSS findings on magnetic resonance imaging. The prevalence of low back pain and symptomatic LSS was compared between those with or without spondylolisthesis. Furthermore, we determined the association between the amount of slippage and presence of symptomatic LSS. The prevalence of spondylolisthesis at any level was 15.8% in the total sample, 13.0% in males, and 17.1% in females; the prevalence was not significantly different between males and females (P = 0.09). In both, males and females, symptomatic LSS was related to spondylolisthesis [odds ratio (OR): 2.07; 95% CI: 1.20-3.44]; however, no such association was found for spondylolisthesis and presence of low back pain. The amount of slippage was not related to the presence of symptomatic LSS (P = 0.93). This population-based cohort study revealed that lumbar spondylolisthesis had a closer association with leg symptoms than with low back pain. There was a significant difference in the presence of symptomatic LSS between participants with and without spondylolisthesis. However, the amount of slippage was not related to the presence of symptomatic LSS. 3.

The method of constructing the diagrams of tangential stresses in the contact zone of an axle wheel with soil

The process of interaction of the driving wheels of mobile energy resources with soil is considered. A computational and experimental method is proposed for plotting the shear stresses in the contact zone of the skid wheel with a supporting surface, based on the use of normal stresses obtained for specific ground conditions. The character of the interaction of the driving wheel of the tractor with various types of supporting base has been studied in detail: a dirt road, stubble, a field prepared for sowing. It is revealed that, contrary to the generally accepted ideas, the slipping wheel has practically no adhesion zone in the contact spot. After touching the tiller of the supporting surface, it immediately begins to shift backward. Therefore, when calculating the shear stresses in the contact spot of the skid wheel with the support, it is more correct to assume that the shift of the elementary points increases as they move away from the entrance to the contact zone and depends on the amount of slippage. When rolling the drive wheel, even with a slight slippage on the deformable surface, there is practically no bonding zone at the point of contact between the two contacting bodies (the tire and the ground). On the surface of the soil, normal stresses reach their maximum, gradually decreasing with increasing depths of its layers. With a slight slipping (up to 10 %), the maximum tangential stresses occur at the back of the contact spot - in the zone of the largest shear deformations of the soil. As the traction load increases, the tangential contact stresses are shifted to the center of the contact patch - to the zone where the deformations of the soil did not exceed the optimum level characteristic for each specific soil type. Thus, the elongation of the tire contact patch is effectively up to a certain level limited by the limiting values of shear deformation of the soil above which the tangential stresses cease to grow and even begin to decline for most types of cohesive soils. It was found that an excessive increase in shear deformation of the soil at slippage leads to a decrease in the efficiency of the wheeled propulsor.

Association of Lumbar Spondylolisthesis with Low Back Pain and Symptomatic Lumbar Spinal Stenosis in a Population-Based Cohort: The Wakayama Spine Study

Introduction Despite the high number of surgeries performed for spondylolisthesis, the basic epidemiology of lumbar spondylolisthesis in the general population is not well known. The aim of this study was to clarify the association of lumbar spondylolisthesis with symptomatic lumbar spinal stenosis (LSS) in a population-based cohort study with participants representing the general Japanese population. Patients and Methods This cross-sectional study included 938 participants (308 men, 630 women; mean age, 67.3 years; range, 40–93 years). Lumbar radiographs were obtained for all the participants, with lumbar spondylolisthesis classified as a slip of more than 5% on the lateral view. The diagnosis for symptomatic LSS required the presence of both leg symptoms and radiographic lumbar spinal stenosis on magnetic resonance imaging. The presence of symptomatic LSS was compared between participants with and those without lumbar spondylolisthesis using statistical analysis. Furthermore, we clarified the association between the amount of slippage and the presence of neurogenic claudication. Results The prevalence of spondylolisthesis at any level was 15.8% overall, 13.0% in men and 17.1% in women, with no significant difference between genders. The prevalence of symptomatic LSS was 9.0% overall, 9.4% in men, and 8.7% in women. Logistic regression analysis after adjustment for age, gender, and BMI showed that there existed a significant association of spondylolisthesis with symptomatic LSS overall. (OR: 2.07, 95% CI: 1.20–3.44). While, among participants with L4 anterior spondylolisthesis, the mean percentage slip in those with neurogenic claudication was 14 ± 1.2% and those without was 14 ± 0.5%, with no significant difference. Conclusion This population-based cohort study revealed that there was a significant association of spondylolisthesis with neurogenic claudication, although the amount of slippage was not related to the presence of neurogenic claudication.

Optimization of the Racking Hitch Knot: How Many Half Hitches and Which Suture Material Provide the Greatest Security?

Reliable methods of fixation of soft tissue and bone are of utmost importance in reconstructive shoulder surgery and in many orthopaedic applications. Current methods of securing lesser tuberosity osteotomies performed during shoulder arthroplasty and tuberosity fixation performed during repair of proximal humeral fractures often rely on alternating half hitches or surgeon's knots regardless of the suture configuration used passing through the tissue (eg, Mason-Allen, Krackow). The racking hitch knot in contrast to half hitches allows sequential tightening, even under tension, with minimal risk of knot slippage or premature locking. These knot characteristics allow the surgeon to stepwise improve their reduction before committing and locking a construct, preventing hanging knots or under-tensioned repairs. However, little data exist to support the use the racking hitch knot to guide decision making regarding how to back up the knot or to explain the effect of suture material on security and strength. The objectives of our study were (1) to identify the optimal number of half hitches necessary to maintain knot security for a single knot; (2) to evaluate if a difference exists in the relative behavior of racking hitch knots when tied using different suture materials; and (3) to define the biomechanical differences between the racking hitch and two other knot configurations commonly used in shoulder surgery (Weston and square knots). Using an Instron device we tested the effect of adding supplemental half hitches (from one to four) to the racking hitch. Additionally, a selection of commercially available braided nonabsorbable polyethylene sutures and different knot configurations (racking hitch, Weston knot, and square knot) also were tested. Data were compared using ANOVA. Increasing the number of half hitches improved knot performance in peak load testing and cyclic testing, revealing a significant difference between the racking hitch supplemented with one and four half hitches (199.2 N versus 428.8 N, p < 0.05). Force Fiber™ #2 (359.6 N) and FiberWire(®) #2 (302 N) showed increased loads to failure compared with Ethibond Excel™ #2 or Force Fiber™ #3/4, whereas Ethibond Excel™ had the least amount of slippage during cyclic testing (0.09 mm). The racking hitch knot had considerably higher loads to failure (359.6 N) than the Weston (145.2 N) or square (77 N) knots. The racking hitch knot exhibited significantly higher loads to failure and comparable knot slippage (elongation during cyclic testing) when compared with other commonly used knots. According to the biomechanical data, the addition of four half hitches to supplement the racking hitch and the choice of FiberWire(®) #2 or Force Fiber™ #2 suture resulted in increased knot security. This knot adds a tool to the arsenal for surgeons best suited for repairs requiring a high degree of knot security and reliable tissue tensioning.

Continuous wave peristaltic motion in a robot

We have developed several innovative designs for a new kind of robot that uses a continuous wave of peristalsis for locomotion, the same method that earthworms use, and report on the first completed prototypes. This form of locomotion is particularly effective in constrained spaces, and although the motion has been understood for some time, it has rarely been effectively or accurately implemented in a robotic platform. As an alternative to robots with long segments, we present a technique using a braided mesh exterior to produce smooth waves of motion along the body of a worm-like robot. We also present a new analytical model of this motion and compare predicted robot velocity to a 2D simulation and a working prototype. Because constant-velocity peristaltic waves form due to accelerating and decelerating segments, it has been often assumed that this motion requires strong anisotropic ground friction. However, our analysis shows that with smooth, constant velocity waves, the forces that cause accelerations within the body sum to zero. Instead, transition timing between aerial and ground phases plays a critical role in the amount of slippage, and the final robot speed. The concept is highly scalable, and we present methods of construction at two different scales.

Synthesis and X-ray structure of novel 2- and 3-heteroatom-substituted ansa-zirconocene complexes

New ansa -zirconocene complexes with amino and alkoxy substituents attached to the η 5 -bonded indenyl fragment have been synthesized. Crystallographic analysis showed that heteroatom substituents, especially those in the 3-position on the indenyl ligand, have a substantial effect on the structure of metallocenes leading to an increase in the gap aperture in those complexes. New ansa -zirconocene complexes with amino ( 8 – 11 ) and alkoxy ( 12 ) substituents attached to the η 5 -bonded indenyl fragment have been synthesized by the reaction of ZrCl 4 with the appropriate dilithium salt in toluene. In addition to HRMS, NMR spectroscopy, and elemental analysis, all new metallocenes have been characterized by single crystal X-ray analysis. Crystallographic analysis showed that heteroatom substituents, especially those in the 3-position on the indenyl ligand, have a substantial effect on the structure of metallocenes leading to an increase in the gap aperture in those complexes. Slippage of the indenyl fragments toward η 3 -bonding was found to correlate with the electron donating ability of the substituent in the 3-position, being larger for amino than alkoxy substituents. Based upon the amount of slippage, 3-amino-substituted indenyl complexes bear strong resemblance to a fluorenyl complexes.

Active Surface Topographies in Constrained Hydrogel Films

AbstractPeriodic wrinkles or corrugations can appear on the free surfaces of constrained hydrogel films. The constraint generates a residual compressive stress that is partially relieved through deviation of free surfaces from a planar configuration. The morphology, amplitude and wavelength of the surface instability are generally well-defined and depend on the strength of the constraint. If swelling of the hydrogel overcomes the constraint, the film can slip along its substrate, altering the resultant compressive stress and surface topography. By tuning this slippage, we aim to direct the surface features presented by thin hydrogel films. Active control of surface morphology could have important implications in several applications ranging from sensors to controlled cell attachment and detachment.In this work, we discuss a method of tuning the amount of slippage and surface topography of patterned poly(N-isopropylacrylamide) (poly-NIPAAm) films. The films were fabricated from photo-crosslinkable polymers comprising NIPAAm and photo-active methacroyloxy-benzophenone (MaBP) monomers. The patterned films were anchored to a substrate through a hydrogen-bonding self-assembled monolayer. The relationship between pattern geometry, pattern dimensions, and solvent were investigated with respect to the mechanical instability generated at the free surface. We observed that the wavelength, width, and amplitude of the instability always increased with the thickness of the polymer pattern. The morphology of the surface instability, however, was especially sensitive to thickness of the pattern, the solvent, and the spatial position with respect to the edge of polymer pattern. If the slippage of the film against the substrate is minimal, a wrinkle pattern in the form of bicusps was observed. If the compressive stress exceeded the hydrogen-bonding anchors, slippage of the film generated either a blister pattern or a honeycomb pattern.

GENETIC SCREENING AND SELFHOOD

Click to increase image sizeClick to decrease image size Notes 1. See, in particular, Robertson (1994 Robertson, John A. 1994. Children of choice: Freedom and the new reproductive technologies, Princeton: Princeton University Press. [Google Scholar]). 2. See, for instance, Buchanan et al. (2000 Buchanan, Allen, Dan, W. Brock, Norman, Daniels and Daniel, Wikler. 2000. From chance to choice: Genetics and justice, Cambridge and New York: Cambridge University Press. [Crossref] , [Google Scholar]) and Resnik (1997 Resnik, David B. 1997. Genetic engineering and social justice: A Rawlsian approach. Social Theory and Practice, 23(3): 427–49. [Crossref], [PubMed] , [Google Scholar]). 3. While there is much fantastic and philosophical speculation about enhancing desirable traits such as intelligence, memory and physical agility and endurance, at least for now, genetic modification is technically more in the realm of gene replacement therapy and epigenetics, which permits the regulation of gene expression. 4. See Fukuyama (2003 Fukuyama, Francis. 2003. Our posthuman future: Consequences of the biotechnology revolution, London: Profile Books. [Google Scholar]). 5. There is, however, a considerable amount of slippage throughout Habermas's essay and he does not always remain within the limits of this epistemic approach. 6. It should be noted that I use the term ‘epistemic regimes’ in reference to Michel Foucault's analysis of the modern ‘episteme’ in books such as The Order of Things (1970 Foucault, Michel. 1970. The order of things: An archaeology of the human sciences, New York: Random House. [Google Scholar]), though I am not suggesting that the details of his analysis need be adopted. 7. See Nancy's ‘Introduction’ to Who Comes After the Subject? (1991). 8. Although Nancy references Arendt infrequently, he does acknowledge the significance of her reflections on ‘human plurality’, especially in relation to Heidegger. Related to this, his emphasis on the notion of ‘who’ and on birth draws on Arendt, as do his reflections on spacing in the book The Experience of Freedom (1995). It should be noted that Nancy's reflections on ontology and ethics constitute an extremely complex and often allusive engagement with the Western philosophical tradition, and especially with Kant, Hegel and Heidegger. My comments on his work are brief and necessarily leave much to be explained further. 9. See Nancy (2000 Nancy , Jean-Luc 2000 . Being singular plural . Translated by Robert D. Richardson and Anne E. O'Byrne . Stanford : Stanford University Press .[Crossref] , [Google Scholar]) for a further explication of the notion of singularity and its necessary relation to co-presence or ‘being-with’, itself a central idea in his extension of Arendt. 10. On the issue of how the notion of singularity relates to conceptions of the subject, see especially Nancy's ‘Introduction’ to Who Comes After the Subject? (1991 Derrida, Jacques. 1991. “‘Eating well,’ or the calculation of the subject”. In Who comes after the subject?, Edited by: Eduardo, Cadava, Peter, Connor and Jean-Luc, Nancy. New York: Routledge. [Google Scholar]) and, in the same volume, the interview with Jacques Derrida: ‘“Eating well,” or the calculation of the subject’. See also Nancy (1995). 11. This depends in part on the breadth of one's definition of the ‘technological’. 12. I emphasise ‘child’ here because, on the face of it, PGD does allow that embryos—or rather pre-embryos—be treated as fungible. 13. I am presupposing the success of the PGD and IVF process to make my point here, which in practice is far from guaranteed. For an insightful empirical study of the use of PGD in the United Kingdom, see Franklin and Roberts (2006 Franklin, Sarah and Roberts, Celia. 2006. Born and made: An ethnography of pre-implantation genetic diagnosis, Princeton: Princeton University Press. [Crossref] , [Google Scholar]).

How Tax Credits Have Affected the Rehabilitation of the Boston Office Market

This paper is concerned with the extent to which rehabilitation tax credits affect the conditional probability of commercial real estate rehabilitation. The analysis suggests that rehabilitation tax credits have been a significant determinant of the conditional probability of rehabilitation in the Boston office market. A significant portion of rehabilitation tax credit investment is investment that would have been invested elsewhere, about 60% to 65% in certain periods, but rising to as high as 90% in other periods. The findings indicate that the rehabilitation tax credit has a significant and substantial influence on the conditional probability of rehabilitation. The findings also reveal that the greatest amount of slippage, not too surprisingly, generally occurs when the tax credit is low and when the gain from rehabilitation before the tax credit is high.

An elastoplastic continuum model for a wound roll with interlayer slippage

In paper industry the nip rollers used in the winding process and the clamping devices used to lift rolls during transport cause interlayer slippage in the rolls. A certain amount of slippage is acceptable, and sometimes even desired, but excess slippage can, in the worst case, render the roll useless. Numerical analysis of the stresses and strains in the roll can aid in the design process of winders and clamps. Since the number of layers in a roll may be several thousands, a full contact mechanical model of the layered structure is not feasible. The computational cost is significantly reduced by using a continuum approach and considering the layered structure as a continuum with slip surfaces. In this paper a model for rolls wound of orthotropic material is developed. The elastoplastic jointed material model with shear limits based on Coulomb friction is extended to orthotropic materials. The model is implemented into the FE-program ABAQUS and used to study the stresses, layer-to-layer slippage and J-line formation in a paper roll in rolling contact against a winding drum. The deformation of a roll due to compressive clamping forces is also calculated. It is found that the plastic flow (i.e., slippage) significantly affects the stress distribution in the roll.

Wire failures in ropes and their influence on local wire strain behaviour in tension-tension fatigue

Experimental work using multiple strain gauges has investigated the take-up of load by a wire at either side of a break and how this is affected by fatigue cycling. In addition the effect of a wire break on other wires at the same cross-section has been investigated. The results indicate that a significant amount of slippage can occur for up to 20000 cycles after a wire has broken, causing the load transfer length to change from two strand lay lengths to around three. The transfer length was found to be much lower for Lang's lay rope than ordinary lay and this was attributed to the greater interlayer forces in Lang's lay ropes. With respect to the effect of wire breaks on other wires at the same cross-section it was found that the primary increase is in the strains in wires in the same strand, although wire strains in adjacent strands also increase to some extent. Wires on the opposite side of the rope construction were found to show a decrease in surface strain after the break which may be attributed to local bending effects.

Characteristics of the Turning Motion of a Tracked Vehicle under Traction on a Loose Sandy Soil —Inner/Outer Track During Driving Action—

The turnability characteristics of a flexible tracked vehicle under traction on a loose sandy flat surface are investigated theoretically and experimentally for both the inner and the outer track while being driven. Based on soil mechanics relationships between the surface and the flexible track belt, the turnabilities of the inner and the outer track are considered looking at the surface shear resistance as a function of lateral and longitudinal slip velocity and the amount of slippage. Using terrain-track system constants, the relationships of the amount of depression, the thrust, the compaction resistance of the inner and the outer track, the effective tractive effort, the turning moment of a given tracked vehicle, and the turning radius are predicted for several kinds of steering ratio. From the results, it is determined that the vehicle speed decreases with the increment of turning radius along with the increment of resultant effective tractive effort, and the slip ratio of the outer track is always larger than that of the inner track. The amounts of depression of the front idler of the inner and the outer track decrease with slip ratio while those of the rear sprocket increase. The turning resistance moment of the inner track is always larger than that of the outer track for each surface shear resistance.

Self loosening behavior of bolted joints under transverse cyclic loading.

Although plastic materials are widely used as insulators in electric equipment, the mismatch of the thermal expansion cefficients between the plastic and the metallic materials may cause problems. For instance, in bolted joint structures the mismatch of the thermal expansion coefficients causes transverse cyclic relative slippage and loosening of bolts. In the work described in this paper the loosening behavior of these bolted joints under transverse loading was analyzed taking into account the relative slippage on the interface between the bolt head and the jointed body. The amount of slippage was calculated using this mismatch of the thermal expansion between both the jointed bodies and the bending elastic deformation of the bolts. The analytical results were confirmed by experimental results. Using these results we identify highly durable bolted fastening structures.