Structure Deficiency Research Articles

Graft Extrusion Related to the Position of Allograft in Lateral Meniscal Allograft Transplantation: Biomechanical Comparison Between Parapatellar and Transpatellar Approaches Using Finite Element Analysis

To compare the relation of extrusion of the graft with the position of the allograft between the parapatellar and transpatellar approaches and to show the primary importance of an anatomically correct position by comparing the chondroprotective effects after lateral meniscal allograft transplantation (MAT) with those of normal healthy knees. Geometrical data from patients who underwent magnetic resonance imaging evaluation after lateral MAT were used as baseline input data for 3-dimensional and finite element analysis. The inclusion criteria were patients with symptomatic knees that had undergone meniscectomy who underwent lateral MAT with a minimum follow-up of 2years. Patients with generalized arthritis, lower limb malalignment with greater than 5° valgus or varus, or uncorrected joint instability caused by ligament structure deficiency were excluded from this study. Patients were divided into the parapatellar group (25 patients) and transpatellar group (20 patients) according to surgical approach. The mean width of the extruded meniscus was 4.32 ± 0.58mm in the parapatellar group and 3.00 ± 0.61mm in the transpatellar group (P < .0001). The mean relative percentage of extrusion was 42.48% ± 7.82% in the parapatellar group and 28.21% ± 4.49% in the transpatellar group (P < .0001). The mean angle between the bony bridge and the center of the tibial plateau was significantly greater in the parapatellar group (16.69° ± 2.68°) than in the transpatellar group (5.29° ± 1.55°, P < .0001). The mean distance from the entry point of the bony bridge to the center of the tibial plateau was also greater in the parapatellar group (16.68 ± 2.56mm) than in the transpatellar group (10.81 ± 1.37mm, P< .0001). The distance from the entry point of the bony bridge to the center of the tibial plateau significantly influenced the obliquity of the bony bridge in the parapatellar group (P= .002). On finite element analysis, the transpatellar approach was more similar to the intact knee model in terms of the contact area and stress of the lateral meniscus and medial meniscus as well as the maximum compressive and maximum shear stresses. Compared with the parapatellar approach, the transpatellar approach had lower maximum contact stress on the menisci and lower maximum compressive stress and maximum shear stress on the femoral and tibial articular surfaces. The transpatellar approach led to a more anatomically correct positioning of the grafted meniscus with less meniscal extrusion than did the parapatellar approach in lateral MAT. Furthermore, the transpatellar model had lower maximum contact stress on the menisci than did the parapatellar model, and it also had lower maximum compressive stress and maximum shear stress on the femoral and tibial articular surfaces. The transpatellar approach is likely to have a more anatomic placement of graft with a subsequent greater chondroprotective effect; thereby, it may reduce the overall risk of degenerative osteoarthritis after lateral MAT.

An Appraisal of ‘Developer-Finance’ Option for the Redevelopment of Family Properties in Lagos, Nigeria

Family properties bequeathed by deceased parents are to be found in considerable numbers within the core and central business district (CBD) of most Nigerian older cities. A number of these properties are old and derelict having suffered considerable physical deterioration and functional obsolescence. Such properties are therefore not making the highest and best use of their respective sites while they possess considerable latent values waiting to be released by injecting capital into their redevelopment. However, given their ownership structure and title deficiency among others, this category of properties hardly qualifies for funding through the conventional methods. More often than not, ‘developer-finance’ happens to provide the only pliable method of financing their redevelopment. Regretfully, this mode of financing often runs into trouble with the project either poorly executed or abandoned midway. This paper examines the manner in which ‘developerfinance’ is currently practiced in Lagos Metropolis with a view to identifying grey areas and making recommendations for needful improvement. The study revealed, among others, that the use of ‘developer finance’ in the study area is limited in scope - limited to certain geographical areas, certain categories of properties, and also limited in terms of the scale of development. The study also revealed a number of fundamental but avoidable pitfalls which tend to endanger the practice and aggravate the associated risks. Remedies are suggested to forestall abuses and eliminate observed lapses.Key words: Developer-finance, Inherited property, Redevelopment, Nigeria.

Quantile hydrologic model selection and model structure deficiency assessment: 1. Theory

A theory for quantile based hydrologic model selection and model structure deficiency assessment is presented. The paper demonstrates that the degree to which a model selection problem is constrained by the model structure (measured by the Lagrange multipliers of the constraints) quantifies structural deficiency. This leads to a formal definition of model structure deficiency (or rigidity). Model structure deficiency introduces a bias in the prediction of an observed quantile, which is often not equal across quantiles. Structure deficiency is therefore diagnosed when any two quantile predictions for a given model structure cross since unequal bias across quantiles result in quantile predictions crossing. The analysis further suggests that the optimal value of quantile specific loss functions order different model structures by its structure deficiencies over a range of quantiles. In addition to such novelties, quantile hydrologic model selection is a frequentist approach that seeks to complement existing Bayesian approaches to hydrological model uncertainty.

Quantile hydrologic model selection and model structure deficiency assessment: 2. Applications

Quantile hydrologic model selection and structure deficiency assessment is applied in three case studies. The performance of quantile model selection problem is rigorously evaluated using a model structure on the French Broad river basin data set. The case study shows that quantile model selection encompasses model selection strategies based on summary statistics and that it is equivalent to maximum likelihood estimation under certain likelihood functions. It also shows that quantile model predictions are fairly robust. The second case study is of a parsimonious hydrological model for dry land areas in Western India. The case study shows that an intuitive improvement in the model structure leads to reductions in asymmetric loss function values for all considered quantiles. The asymmetric loss function is a quantile specific metric that is minimized to obtain a quantile specific prediction model. The case study provides evidence that a quantile-wise reduction in the asymmetric loss function is a robust indicator of model structure improvement. Finally a case study of modeling daily streamflow for the Guadalupe River basin is presented. A model structure that is least deficient for the study area is identified from nine different model structures based on quantile structural deficiency assessment. The nine model structures differ in interception, routing, overland flow and base flow conceptualizations. The three case studies suggest that quantile model selection and deficiency assessment provides a robust mechanism to compare deficiencies of different model structures and helps to identify better model structures. In addition to its novelty, quantile hydrologic model selection is a frequentist approach that seeks to complement existing Bayesian approaches to hydrological model uncertainty.

Microwave rapid preparation of LiNi0.5Mn1.5O4 and the improved high rate performance for lithium-ion batteries

Spinel LiNi0.5Mn1.5O4 is rapidly synthesized by using microwave heating at 700°C for 7min (MW700C7m). The crystal structure, morphology and elemental deficiency of MW700C7m are carefully studied by Rietveld refinement of XRD patterns, scanning and transmission electron microcopy, and redox titration, in comparison with the sample synthesized by conventional heating at 700°C for 48h (CP700C48h). Both MW700C7m and CP700C48h are well refined using the Fd-3m space group. Microwave irradiation not only accelerates the crystal growth of spinel LiNi0.5Mn1.5O4, but also results in preferential growth behavior. Cyclic voltammetry (CV) of MW700C7m presents low polarization and better structural stability. Galvanostatic charge–discharge cycling of MW700C7m and CP700C48h have minor Mn3+/4+ redox peaks beside Ni2+/4+ redox peaks. At normal current rate, both MW700C7m and CP700C48h present good capacities, close to the theoretical value. At high current rate, MW700C7m delivers much better capacity than CP700C48h. MW700C7m delivers capacity of 108.7mAhg−1 at 10C-rates and fades less than 1% after 150 cycles. The severe capacity loss of LiNi0.5Mn1.5O4 cathodes is still a problem when cycling is carried out at high and low temperatures. Under various temperatures, the contribution and effect of Mn3+/4+ and Ni2+/4+ redox for the capacity are studied in detail.

A Study on Semi-Physical Simulation for Marine Gas Turbine Generator Set Based on Hardware Agent

The simulation research on gas turbine generator set has the important practical significance for its main development direction in marine power plant. The research object is semi-physical simulation for marine gas turbine generator set. This paper presents a new type of semi-physical simulation scheme based on “hardware agent” through reviewing the existing the structure characteristics and deficiency of semi-physical simulation system of gas turbine device. The theoretical basis and operation control strategy and framework of the new project were discussed. The experiments on sudden load-up and load rejection were made based on new type of semi-physical simulation system for marine gas turbine set and had a good test effect.

Aluminium speciation and phytotoxicity in alkaline soils

Aim Highly alkaline soils (pH > 9.0) may adversely affect agricultural crop productivity. Problems encountered include poor structure and nutrient deficiency. Research based on solution cultures suggests that aluminium (Al) phytotoxicity may occur in soils with pH > 9.0, but little research has been undertaken on actual soils under controlled conditions. The nature of the Al species responsible and the pH regime of the soils when this occurs are unknown.

A study on utilizing a chloride bath to electroform MEMS devices with high aspect ratio structures

Addressing the problems that occurred for electroforming of MEMS devices with high aspect ratio and geometry-complex structures, the electrochemical properties of a chloride bath are studied in this paper. It has been found that the tensile stress of nickel film from the chloride bath with the addition of saccharine is significantly reduced. Our results also suggested that, compared to the commonly used sulfamate bath, the chloride bath has higher throwing power and covering power, possibly due to its higher conductivity and polarizability. In addition, the presence of saccharine provided a finer grain nickel film with a smoother surface. Furthermore, the MEMS-based latching devices with narrow bars of 50 µm width and 500 µm thickness were obtained from the chloride bath, while the same devices with structure deficiency (incomplete structures) were frequently observed from the sulfamate bath. The finite element method simulations using the ANSYS software for the current density distribution on the surface of different aspect ratio latching structures were carried out. After considering the electrochemical perspectives from both baths, the mechanisms for the deficiency formation from the sulfamate bath and the absence of the deficiencies from the chloride bath were proposed and discussed.

The influence of heat treatment on the properties of shape memory fibers. II. Tensile properties, dimensional stability, recovery force relaxation, and thermomechanical cyclic properties

AbstractShape memory fibers (SMFs) were prepared via a melt spinning process. The fibers were subject to different heat treatments to eliminate internal stress and structure deficiency caused during the melt spinning process. The influences of heat treatments on the SMF thermal properties, molecular orientation, tensile properties, dimensional stability, recovery force relaxation, and thermomechanical cyclic properties were studied. It was found that the heat treatments increased soft segment crystallinity and phase separation while decreased molecular orientation. The low‐temperature heat treatment increased the breaking elongation, shape fixity ratios, and decreased boiling water shrinkage while shape recovery ratios were decreased. High‐temperature treatment increased both the shape recovery ratios, fixity ratios, recovery stress stability and at the same time decreasing the fiber mechanical strength. The results from differential scanning calorimetry, molecular orientation apparatus, and cyclic tensile testing were used to illustrate the mechanism governing the mechanical properties and shape memory effect. To obtain comprehensive outstanding properties, the SMF is expected to be treated at a high temperature because of the hard segment high glass transition temperature. Unfortunately, the heat treatment could not be conducted at a too high temperature because the SMF became too tacky and soft due to the melting of the soft segment phase. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Influence of heat treatment on the properties of shape memory fibers. I. Crystallinity, hydrogen bonding, and shape memory effect

AbstractShape memory fibers (SMFs) were prepared via melt spinning. The fibers underwent different heat treatments to eliminate internal stress and structure deficiency caused during melt spinning. The influences of heat treatments on the SMF crystallinity, molecular orientation, hydrogen bonding, and shape memory behavior were studied. It was found with increasing heat‐treatment temperature, the soft segment crystallinity, crystallite dimension, and microphase separation increased, and the hydrogen bonding in the hard segment phase increased. Low temperature heat treatments decreased the shape recovery ratios while increasing the shape fixity ratios as a result of internal stress releasing and molecules disorientation. High temperature heat treatments increased the hard segment stability. Increasing heat‐treatment temperature resulted in the improvement of both the shape recovery and fixity, because it promoted the phase separation. The results from DSC, DMA, XRD, and FTIR were used to illustrate the mechanism governing these properties difference. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Structural inhomogeneity effects in resistive superconducting transitions of the magnetic superconductor RuSr2(Gd1.5Ce0.5)Cu2O10−δ

The study of granular effects in resistive superconducting transitions of ceramic ruthenocuprate RuSr2(Gd1.5Ce0.5)Cu2O10−δprepared by a solid-state reaction method is presented for samples as prepared (ASP) and annealed (12 hours at 845°C) in pure oxygen at 62 atm. The resistive transitions for different measuring currents and applied magnetic fields (up to 8 T) bear evidence of granularity effects determined by inhomogeneous structure of the samples. This is dictated by the polycrystalline structure (with a grain size of a few μm) and oxygen deficiency in grain boundary regions. The resistive curves show clearly the intragranular and intergranular superconducting transitions, the intergranular superconductivity being determined by the Josephson coupling between the grains. This has allowed determination of intragranular (Tc0) and intergranular (Tcg) critical temperatures, which are ≈ 34 K and ≈ 9.4 K in ASP sample, and ≈ 37.3 K and ≈ 32.8 K in the 62-atm sample in zero field. The magnetic-field dependences of these characteristic temperatures were studied and discussed. In general, the granularity effects are most pronounced in the ASP sample where great sensitivity to applied current and low magnetic field is found. These effects become, however, much weaker after oxygen annealing.

Crystal structure and oxygen deficiency of zirconium-oxide nano particles

Crystal structure and oxygen deficiency of zirconium-oxide nano particles

Nature of structure defects in rhombohedral series of La1−xAxMnO3+δ (A=Na, K)

A series of polycristalline samples of the type La1−xAxMnO3+δ (A=Na, K), quenched in air at 800°C, have been analyzed by X-ray, sample density and average valence of Mn ions, in order to determine structure type defectiveness and its evolution vs. atomic fraction of Na and K. It is found that from crystallochemical point of view, both the series are highly similar. They represent solid solutions of rhombohedral symmetry and of the perovskite structure type, both extending slightly over xA∼0.25. Variation of the average valence of Mn ions in the series, confirms initial structure deficiency (2Δ) of the binary matrix to be of cationic type i.e. La(1−Δ)Mn(1−Δ)O3+Δ, partly compensated by the excess oxygen (Δ), the latter as presumably located in vacant positions of the metal sublattices. Within the domain of homogeneity, the solid solutions exhibit some anomalies at xNa∼0.138 and at xK∼0.147, both connected with a substantial change of the structure type defectiveness and clearly seen on xA variations of the (La=Mn)-site deficiency (Δ). The experimental sample densities indicate that the excess oxygen, present in the matrix, quickly disappears vs. lanthanum substituent (at xNa∼0.04 and at xK∼0.05), but the cationic deficiency persists in the series up to the concentrations of the anomalies given above where it vanishes. On further increase of sodium or potassium content, the crystal structure, being free of any defects, starts to exhibit an increasing level of oxygen deficiency Δoxyg=(3+2x−VMn)/2.

Studies of BaO–In 2O 3–CuO ternary system : Part II: crystallochemical characterization of the (β)-solid solution

A detailed crystallochemical characterization of the (β)-phase found in BaO–In 2O 3–CuO ternary system at 930°C is presented. The phase originates from binary terminal Ba 2In 3O 6.5 (Ba 1.6In 2.4)O 5.2 and expands into the ternary system as a triangularly shaped domain, resulting from a double substitution of the (Ba 1.6+ m In 0.4− m )(In 2− n Cu n )O 5.2−( m+ n)/2 type. The phase exhibits an already characterized crystal structure, known as the ‘doubled’ perovskite type, which was earlier ascribed to Ba 2InCuO 4.5 and to the series of Ba 2In 2− x Cu x O 5−Δ type solid solution. Based on a comparison of the experimental sample densities with those calculated for several models of possible distribution of the M-structure components it was shown that up to 50 at.% Ba, only oxygen deficiency persists in the crystal structure of the (β)-phase. However, on crossing the above mentioned concentration, an increasing number of vacancies appear in its (In+Cu) sublattice (the perovskite B-site), thus additionally increasing the overall structure deficiency. In spite of this, stability of the crystal structure increases.

Pulsed KrF laser annealing of Ni/Si0.76Ge0.24 films

Pulsed KrF laser annealing can suppress the island structure formation and Ge segregation associated with the interfacial reactions of Ni/Si0.76Ge0.24. For the Ni/Si0.76Ge0.24 films annealed at an energy density of 0.1–0.3 J/cm2 nickel germanosilicide associated with the amorphous overlayer was formed, while at energy densities above 0.4 J/cm2 cellular structures of Ge-deficient Si1−xGex islands surrounded by Ni(Si1−xGex)2 due to the constitutional supercooling occurred. For the continuous Ni(Si1−xGex) films grown at 200 °C, subsequent laser annealing at a higher energy density of 0.6–1.0 J/cm2 caused transformation into homogeneous Ni(Si0.76Ge0.24)2 films without island structure and Ge deficiency which readily appeared on furnace annealing at temperatures above 400 °C. At energy densities above 1.6 J/cm2 the same cellular structures as described above were also noted.

A cluster of esterase genes on chromosome 3R of Drosophila melanogaster includes homologues of esterase genes conferring insecticide resistance in Lucilia cuprina.

We identify an esterase isozyme in Drosophila melanogaster, EST 23, which shares biochemical, physiological, and genetic properties with esterase E3, which is involved in resistance to organophosphate insecticides in Lucilia cuprina. Like E3, the D. melanogaster EST 23 is a membrane-bound alpha-esterase which migrates slowly toward the anode at pH 6.8. Both enzymes have similar preferences for substrates with shorter acid side chain lengths. Furthermore, on the basis of their high sensitivity to inhibition by paraoxon and their insensitivity to inhibition by eserine sulfate, both enzymes were classified as subclass I carboxylesterases. The activity of each enzyme peaks early in development and, again, in the adult stage. Both enzymes are found in the male reproductive system and larval and adult digestive tissues, the latter being consistent with a role for these enzymes in organophosphate resistance. Fine structure deficiency mapping localized Est 23 to cytological region 84D3 to E1-2 on the right arm of chromosome 3. Moreover, we show that the genes encoding three other esterase phenotypes also map to the same region; these phenotypes involve allozymic differences in EST 9 (formerly EST C), ali-esterase activity, defined by the hydrolysis of methyl butyrate, and malathion carboxylesterase activity, defined by hydrolysis of the organophosphate malathion. This cluster corresponds closely to that encompassing E3 and malathion carboxylesterase on chromosome 4 in L. cuprina, the homologue of chromosome 3R in D. melanogaster.

On the crystallochemistry and superconductivity of the (Bi 1±xCu ±x) 8Sr 6Ca 6Cu 9O 24+z

A series of solid solutions of the (Bi 1−xCu x) 8Sr 6Ca 6Cu 9O 24+z type with 0.08 ≥ x ≥ −0.225 has been prepared in air at 850°C and identified through X-ray, density, average valency of copper and low temperature resistivity measurements. The Cu-rich side of the series starts from x ≅ 0.06, whereas that of Bi-rich one, comparatively wider, reaches composition very close to x = −0.202. Within the single phase region, lattice parameter a of the 2212-structure type unit cell, remains practically constant (around 0.54 nm). At the same time, the parameter c exhibits a regular decrease vs. growing concentration of bismuth and finally it reaches the value 3.0625 nm at x = −0.202. The average valency of copper within the series shows a minimum value 2.17 at x = 0.00. Starting from this value it grows up linearly in both directions, slightly along the Cu-rich side and more efficiently along the Bi-rich one. The atomic content of the elementary unit cell (Z), expressed as number of molecules of MeO 1+y-type (Me = sum of the metallic structure components in their atomic fractions) and calculated from sample densities, indicates that the structure deficiency is characteristic of all the series. However, within its Bi-rich part the deficiency occurs to be much deeper than in the Cu-rich equivalent. Thus, the intermediate composition with x = 0 i.e. Bi 8Sr 6Ca 6Cu 24+9V(Cu)/2, characteristic of minimum deficiency, minimum valency of copper and minimum T c, divides the series into two sub-regions, each of extremely different type of structure deficiency and different critical temperature behaviour.

Transport critical current density of melt-processed (QMG) YBa 2Cu 3O x bulk superconductors

Transport critical currents of melt-processed (QMG) YBa 2Cu 3O x bulk superconductors were measured by a d.c. four probe method. The QMC bulk specimens have high J c characteristics of ≈ 1 × 10 4 A cm −2 at 5 T for the magnetic field parallel to a–b plane. The angular dependence of J c upon the direction of applied magnetic field showed some characteristic features which could not be described by simple flux pinning. This indicates that anisotropic pinning is relatively strong. The pinning caused by the layered structure, twin boundaries and oxygen deficiency, as well as pinning by the Y 2BaCuO 5 phase, play important roles in determining the J c of the QMG YBa 2Cu 3O x bulk superconductors.

Social Structure and Food Deficiency

Previous articleNext article No AccessReportsSocial Structure and Food DeficiencyLenore MandersonLenore Manderson Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Current Anthropology Volume 27, Number 3Jun., 1986 Sponsored by the Wenner-Gren Foundation for Anthropological Research Article DOIhttps://doi.org/10.1086/203438 Views: 4Total views on this site Copyright 1986 The Wenner-Gren Foundation for Anthropological ResearchPDF download Crossref reports no articles citing this article.

LAENNEC'S OBSERVATIONS ON PARTIAL DILATATION OF THE HEART

Sluggish oxygen reduction reaction (ORR) is a rate-limiting step in some electrochemical devices such as fuel cells. Thus, the synthesis and development of high performance, inexpensive and durable catalysts for ORR is a necessity. Metallic nanostructures decorated heteroatoms-doped carbons have been recognized as excellent catalysts in energy applications. However, nitrogen-doped partially oxidized three-dimensional carbonaceous supports were seldom studied for ORR. Herein, the synthesis of low Fe-Co bimetallic contents deposited on three-dimensional (3D) activated carbon (AC) is reported as an efficient and cost-effective catalyst for ORR in alkaline electrolyte. In the present work, AC was thermally treated by direct heat in air at 430 °C to enhance its electrochemical activity through increasing structure deficiency. AC and nitrogen doped AC (N-AC) were used to synthesize Fe-Co/AC and Fe-Co/N-AC. In both Fe-Co/AC and Fe-Co/N-AC, low amounts of non-precious Fe and Co nanoparticles were deposited on carbonaceous substrates. The air oxidation process, for partially oxidation of carbon structure and catalyst post treatment, was used for introducing defects to the catalyst structure. The performance of synthesized samples was evaluated by ORR process in alkaline medium.