Sharp Loss Research Articles

48.3: LCD Overdrive Frame Memory Reduction using Scalable DCT‐based Compression

AbstractUsing a scalable DCT‐based compression method of low hardware complexity we have reduced the size of the memory that is required for LCD overdrive. Compression ratios up to 16 do not lead to a noticeable loss of sharpness or artifacts. Due to the application of a novel technique this holds also for still images.

Studies on the Hydrodynamics of Chaotic Bubbling in a Gas‐Liquid Bubble Column with a Single Nozzle

AbstractIn this work, the chaotic bubbling mechanism in a gas‐liquid bubble column with a single nozzle was investigated. The signal for the analysis was the time series of pressure fluctuations measured from a pressure transducer probe placed in the bubble column close to the nozzle. In order to study the bubbling process, statistical analysis, qualitative and quantitative nonlinear analyses were carried out for the pressure fluctuations. Power spectra used as standard statistical measures provided preliminary evidence that bubbling in the middle values of gas flow rates may be chaotic in nature. Phase plots provided a qualitative means of analyzing the fine geometry structure of the attractor reconstructed from the bubbling time signal. Positive finite estimates of the Kolmogorov entropy provided a quantitative evidence of behavior consistent with chaos. Besides previous diagnostic tools, the local nonlinear short‐term prediction was also used as a supplement method. It was found that the bubbling process exhibits a deterministic chaotic behavior in a certain range of the gas flow rate. When increasing the gas flow rate, the sequence of periodic bubbling, primary and advanced chaotic bubbling, and jetting or random bubbling were successively observed. However, no clear period doubling sequence leading to chaotic behavior was observed. The sharp loss of the ability to predict the pressure signal successfully with the nonlinear prediction method provides the strongest evidence of the presence of the chaotic bubbling. The variations of the nonlinear invariants, such as the Kolmogorov entropy and the correlation dimension together with the plot of the correlation integral with the operation conditions, might be developed as potential and effective quantitative tools for flow regime identification of the bubbling process.

A new allele of the mouse hairless gene interferes with Hox/LacZ transgene regulation in hair follicle primordia

A new autosomal recessive mouse mutation, causing loss of hair in homozygous mice 2–3 weeks after birth, arose spontaneously in a colony at the National Institute for Medical Research (NIMR), Mill Hill, London in early 1998. Complementation analysis confirmed that this mutation was an allele of the hairless gene ( hr). The gene symbol hr rhbm (hairless-rhino-bald Mill Hill) was assigned to reflect the source of the colony. Here we show the molecular defect in these mutants, which is a substantial deletion at the 3′-end of the hairless gene. Morphological and immunological analysis of the new hairless mutation was performed at early postnatal stages. In an effort to address the molecular and cellular mechanisms of the hairless phenotype, we analysed developmental stages before the establishment of alopecia. Using a HoxLacZ reporter line of transgenic mice, epidermal placode formation was followed in embryos. Homozygous mutant embryos ( hr rhbmh /hr rhbmh ), containing the LacZ reporter under the control of a Hoxb4 gene enhancer, display sharp loss of LacZ staining in epidermal cells invaginating to form the embryonic hair follicle placode. In the light of targeted mutagenesis data involving a Hox gene in the hair development [Genes Dev. 12 (1) (1998) 11], we discuss the potential implication of the hr rhbmh locus in cascades of Hox gene regulation during embryogenesis.

Hydroxylated secondary dopants for surface resistance enhancement in transparent poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonate) thin films

The addition of small, hydroxylated secondary dopants (SDs) can greatly decrease the surface resistance (SR) of poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonate) (PEDOT–PSS) thin films with virtually no loss in film transparency. For example when 2,2′-thiodiethanol or glycerol are added to an aqueous suspension of PEDOT–PSS, thin films cast from the suspension exhibit approximately five-to-seven-fold decrease in surface electrical resistance while their optical transparencies remain nearly constant, or, in some cases, increase slightly. This behavior is strikingly different from that of conducting polymer films doped with standard ionic dopants, wherein decreases in surface resistance are accompanied by a sharp loss in film transparency. These findings may be important to the development of plastic “throwaway” electronics such as liquid crystal displays (LCDs), organic light emitting diode (OLED) displays, imaging materials for flexible substrates, and organic field-effect transistors (FETs). Studies using mid-IR spectroscopic data and deuterated solvents support the premise that 2,2′-thiodiethanol enhances film properties by stabilizing the PEDOT–PSS electrostatic interactions. This dopant enables formation of films with conductivities as high as 98 S/cm and optical transparencies of 84%. Solution thermodynamic analysis indicates that it exerts a chaotropic effect on the aqueous solvent that may aid its ability to enhance film properties.

Criterion of the appearance of diamond-shaped pores in dispersely filled polymers

Introduction of a small fraction of large particles often embrittles a polymer, and the rupture of the polymer occurs at small relative elongation. The sharp loss of the deformability of the composite is caused by the appearance of so-called diamond-shaped pores [1] observed previously in [2, 3]. It was shown that the size of particles responsible for the appearance of diamondshaped pores is determined by the critical crack opening and, therefore, by the breakdown viscosity of the matrix polymer. Rupture of particles or their separation from the matrix under tension gives rise to the formation of pores whose shape is determined by the size of particles [1]. Small and large particles form oval pores and diamondshaped pores, respectively. With further tension, the two types of pores that appear behave differently. An oval pore develops only along the material-elongation direction. A diamond-shaped pore grows in three directions, parallel and perpendicular to the sample tension axis, in particular, along the sample thickness, which leads to early failure. In polymers deformed by the propagation of a neck, the problem is compounded, because the growth of pores is often localized in the narrow formed neck. As a result, the material breaks down at small macroscopic strain. Although the fracture process (growth of diamond-shaped pores) is typically plastic at the mesoscale, the material behaves as a brittle material at the macroscale. This work aims to determine the dependence of the critical size of particles at which diamond-shaped cracks appear on the properties of the polymer matrix. Lukoten F 3802 medium-density polyethylene, Lipol A4-70 polypropylene, and 168030-070 low-density polyethylene are used for composites. Polymers were filled with powdered-rubber particles with sizes from 50 to 600 μm. A monodisperse filler was obtained by grading the polymers into grain sizes with a standard set of sieves. Each polymer was mixed with rubber particles in a single-screw laboratory extruder. The filler

Nonlinear Bubbling Hydrodynamics in a Gas-Liquid Bubble Column with a Single Nozzle

In this work, the chaotic bubbling mechanism in a gas-liquid bubble column with a single nozzle was investigated. The signal for the analysis was the time series of pressure fluctuations measured from a pressure transducer probe placed in the bubble column close to the nozzle. In order to study the bubbling process, statistical analysis, qualitative and quantitative non-linear analyses were carried out for the pressure fluctuations. Power spectra used as standard statistical measures provided preliminary evidence that bubbling in the middle values of gas flow rates may be chaotic in nature. Phase plots provided a qualitative means of analyzing the fine geometry structure of the attractor reconstructed from the bubbling time signal. Positive finite estimates of the Kolmogorov entropy provided a quantitative evidence of behavior consistent with chaos. Besides previous diagnostic tools, the local non-linear short-term prediction was also used as a supplement method. It was found that the bubbling process exhibits a deterministic chaotic behavior in a certain range of the gas flow rate. When increasing the gas flow rate, the sequence of periodic bubbling, primary and advanced chaotic bubbling, and jetting or random bubbling were successively observed. However, no clear period doubling sequence leading to chaotic behavior was observed. The sharp loss of the ability to predict the pressure signal successfully with the non-linear prediction method provides a strongest evidence of the presence of the chaotic bubbling. The variations of the non-linear invariants, such as the Kolmogorov entropy and the correlation dimension together with the plot of the correlation integral with the operation conditions, might be developed as potential and effective quantitative tools for flow regime identification of the bubbling process.

Dynamics of inflation in Turkey during the 1990s

This article assesses the credibility of disinflation programmes in Turkey during the nineties, where several programmes of reform took place. The empirical results show that there was a sharp loss of credibility at the end of the 1991 and at the beginning of the 1994 and during the Asian crisis. The programme that the Central Bank implemented after the crisis was able to increase the level of credibility of the CBRT policies. Loss of credibility is registered during the end of the 1995, while various political events took place and during the 1997 following the world economic conditions and the outflow of capitals.

Extreme Return Reversal in the Stock Market

According to the efficient markets hypothesis, market returns are unpredictable and random around long-term market norms. In a perfectly efficient market, historical returns offer no useful insight into the formation of future return expectations. Behavioral finance theory suggests otherwise. Even if nobody can predict when the market will take a severe drop (such as down 20%), the overreaction hypothesis suggests that forward-looking returns will be above average after severe market drops. Market evidence presented here shows that severe downturns in the overall market are consistently followed by superior returns during the 12 months following. When investors overreact by giving extreme weight to recent negative returns, they run the risk of missing subsequent above-average rates of return. Going forward, the overreaction hypothesis predicts a reversal of the sharp losses following the collapse of the Internet stock bubble and the terrorist attacks on New York City and Washington.

Flexural and Split Cylinder Strengths of HSC at Elevated Temperatures

This paper investigates the effect of elevated temperature on the flexural strength (FS) and split cylinder strength (SCS) of high strength concrete (HSC). Four concrete mixes of 50, 90, 110, and 130 MPa grade were prepared and subjected to elevated temperature exposure of 200°C and 400°C, and cooled under slow and quick cooling conditions. In addition, 130 MPa grade concrete specimens were also subjected to 100°C and 600°C exposure temperatures to compare FS and SCS under elevated temperatures. It was observed that with the increase in the elevated temperature, the FS and SCS experienced significant losses. The loss was found to be higher for richer concretes. FS was observed to experience a sharp loss at low temperatures that became gradual later at high temperatures. SCS, however, experienced a gradual loss, though sharper than FS, with the increase in temperature. The results indicated that cooling had a significant effect on the residual values and quick cooling caused greater loss in FS and SCS, than slow cooling at elevated temperatures. The quick cooling was noted to produce maximum loss over slow cooling at temperatures around 400°C.

Multifunction pump for handling gaseous liquids in process engineering

Pumping liquids with a high gas content can be problematic, causing sharp losses in head and flow or even total cessation of pump flow. German pump manufacturer SERO believes its Multifunction SRZS Pumps provide the ideal solution for such challenging situations, offering a combination of the advantages of side-channel and radial flow centrifugal pump hydraulics. Together these achieve high pump heads, even at relatively high gas entrainments, combined with low NPSH values. Since its introduction in 1988, some 8000 SRZS pumps have been produced, and the company reports continuing growth in demand.

An empirical test of likelihood and timing of speculative attacks: the case of Malaysia and Singapore

This paper attempts to identify the role of monetary policies in exerting speculative pressure on the Malaysian and Singaporean exchange rates that occurred in 1997. The analysis is based on a Brownian motion model with absorbing barrier. It is shown that the likelihood of devaluation, as reflected in the forward premium, has been highly sensitive to the behavior of M2 and foreign reserves, specifically the M2 to reserve ratio. Thus, periodic sharp losses of foreign reserves—combined with expansionary monetary policy—appear to have contributed to the pressures that resulted in the crisis of 1997.

Electron correlation effects in resonant inelastic X-ray scattering of NaV2O5.

Element- and site-specific resonant inelastic x-ray scattering spectroscopy (RIXS) is employed to investigate electron correlation effects in NaV2O5. In contrast to single photon techniques, RIXS at the vanadium L3 edge is able to probe d-d* transitions between V d-bands. A sharp energy loss feature is observed at -1.56 eV, which is well reproduced by a model calculation including correlation effects. The calculation identifies the loss feature as excitation between the lower and upper Hubbard bands and permits an accurate determination of the Hubbard interaction term U = 3.0 +/- 0.2 eV.

Wavelength Dependence of Photooxidation vs Photofragmentation of Chromocene

Photooxidation and metal−ligand photolysis reactions of bis(cyclopentadienyl)chromium, chromocene, in the range 24 390−15 630 cm-1 are studied in the gas phase by using time-of-flight mass spectroscopic detection. Photooxidation of the intact chromocene molecule unexpectedly dominates in the range 23 530−24 000 cm-1. The relative importance of photooxidation compared to photofragmentation is strongly wavelength dependent. A prominent species at all wavelengths is the chromium ion, but in a wavelength region corresponding to the lowest energy ligand to metal charge transfer excited electronic state absorption, the strongest peak is from the chromocene ion. The excitation spectra are reported for three selected species: chromocene ion, mono(cyclopentadienyl)chromium ion, and the chromium ion. The spectrum obtained by monitoring the metal ion contains sharp peaks that are assigned to neutral chromium atom resonances. Sharp losses of intensities in the molecular ion spectra are observed at these wavelengths. The wavelength dependencies of the photoreactions are interpreted and explained in terms of the identity of the initially populated excited electronic state and the ionization energy of the molecule. When the initially populated excited electronic state is the ligand to metal charge transfer state, the first photon causes minimal bond weakening and the second photon excites the intact chromocene above the ionization energy, resulting in efficient ionization of the parent molecule. When the initially populated state is a lower energy ligand field excited electronic state, bond weakening occurs and absorption of a second photon results in significant photodissociation producing intense fragment peaks dominated by the metal ion peak.

Litter fall, decomposition and nutrient release in three semi-arid forests of the Duero basin, Spain

Summary The production of litter, the weight loss dynamic of forest litter decomposition, and the dynamics of bioelement loss during leaf litter decomposition were determined in three forest ecosystems located in a semi-arid zone of the Duero basin, Province of Zamora, Spain, over 2 years. The three ecosystems were a climax evergreen oak (Quercus rotundifolia Lam.) woodland, a paraclimax stone pine (Pinus pinea L.) forest, and a disclimax maritime pine (Pinus pinaster Sol.) forest. The mean total production of litter in the oak forest was 2320 kg ha ‐1 year ‐1 , quite similar to the P. pinea pine forest, at 2400 kg ha ‐1 year ‐1 and higher than that of the P. pinaster pine forest at 1728 kg ha ‐1 year ‐1 . Leaves and needles accounted for most of this total production (78, 89 and 96 per cent, respectively). No significant differences were found among the different leaf decomposition processes, except for the oak leaves introduced in the pine ecosystems. A relationship between time (independent variable) and the remaining leaf weight was found, which followed a negative exponential curve, DM (dry matter) = A + B exp(‐Ct). About 30 per cent of the weight was lost during the first 4 months. This indicates that climate (semi-arid conditions) speeds decomposition in the short term. The decomposition indices were determined for leaves only and for total litter. Considering total litter and leaves separately, several relations were established for K, Ko and Kd decomposition indices. K and Ko in natural conditions decrease in the following order: evergreen oak > stone pine > maritime pine. The Q. rotundifolia woodland potentially returns a greater amount of N and Ca than both Pinus forests. A litter-bag method was used for the determination of the dynamics of the decomposing leaves. A progressive loss of P and Mg in the decomposing oak leaves and pine needles, and a sharp loss of K were observed: in contrast, a tendency to retain N and Ca was also seen. Pinus pinaster forest had the lowest annual N and P returns.

Effects of Habitat Disturbance and Protected Areas on Mammals of Peninsular Malaysia

I studied a network of small forested areas (2-2744 ha) that are protected as forestry research control sites and nature reserves in Peninsular Malaysia. These areas are officially known in Malaysia as Virgin Jungle Reserves ( VJRs). They are unlogged and are usually part of a larger, generally logged forest. I examined the effects of habitat disturbance on the species richness and composition of the mammal communities in seven of these protected areas ( 70-304 ha) and in adjoining logged forest, exotic monoculture plantation, or "farm bush." Thirty-eight species of mammals were recorded through direct observation, identification of tracks, or other signs. The size of the remaining area of natural forest, including both logged and unlogged forest but not including exotic timber plantations, or farm bush, was the most important factor affecting the mammal communities in all seven areas. The presence of species followed a nested subset pattern. A loss of large herbivores and carnivores, in particular, was apparent between areas of natural forest of 6551 to ≥10,000 ha. When areas of natural forest of ≤459 ha were considered, size continued to be critical; a sharp loss in mammal species richness was apparent between 70 and 164 ha. The area of the natural forest in which a protected area was located largely determined the mammal species richness and composition in the protected area. Differences in habitat quality accounted for the differences in mammal communities between protected areas and their adjoining vegetation. The preservation of small undisturbed areas can effectively enhance certain mammal communities in a disturbed landscape. The survival of some mammal species, however, including the largest carnivores and herbivores, will be determined by the area of surviving forest as a whole. A positive management strategy would be to retain large, continuous areas of forest wherever possible, in preference to fragmenting forest, and to build on existing small protected-area networks, such as the VJR network in Peninsular Malaysia, so that logged forests contain a rich mix of undisturbed protected areas.

Diät und Kostaufbau nach Gastrektomie

Malnutrition and severe weight loss are the most frequent complications after total gastrectomy. Malabsorption, due to loss of stomach reservoir with shortened transit time, bacterial overgrowth and relative pancreatic enzyme insuffciency, have been discussed. Other reasons are inadequate calorie intake explained by lack of appetite, early satiety, disturbance of taste and psychological problems. A correct dietary regimen with 40 kcal/kg body weight/day (15–20% protein, 30–40% fat and 50% carbohydrates) is necessary. Before and after discharge from hospital, patients should repeatedly be introduced by an experienced dietitian to increase the intake of energy and nutrient-rich foods, to increase meal frequency to about 6–8 small-sized meals per day, and to separate solid and liquid food items. Food restrictions should be given only in case persistent problems such as dumping, diarrhea or steatorrhea. For malnourished patients or patients with major problems after operation, a home enteral nutrition via catheter jejunostomy can be organized. Malnutrition and sharp weight loss are not inevitable consequences after total gastrectomy. After an adaptive time the patients are able to stabilize their weight or to gain weight, and about 1 year postoperatively most of the totally gastrectomized patients are able to eat the same nutrients as before the operation. Postoperative disturbances in digestion and a decrease in food intake can be avoided with a careful nutritional follow-up and dietary education, especially in the early postoperative period when patients have the most difficulties with taking adequate nutrition.

Thermal and mechanical properties of ethylene/α-olefin copolymers produced over (2-MeInd)2ZrCl2/MAO system

Thermal and mechanical properties of ethylene/α-olefin copolymers (LLDPE) produced over bis(2-methyl indenyl)zirconium dichloride((2-MeInd)2ZrCl2) were compared with those of LLDPEs synthesized with a conventional heterogeneous Ziegler–Natta (Z–N) catalyst, titanium tetrachloride supported on magnesium diethoxide with diisobutyl phthalate as an internal donor(Mg(OEt)2/DIBP/TiCl4). DSC thermogram of LLDPE by the Z–N catalyst showed that the melting peak moved to a lower temperature region and the peak became broader as the density of LLDPE decreased. On the other hand, in case of LLDPE produced over (2-MeInd)2ZrCl2, the melting peak shifted to a lower temperature zone with the decreasing copolymer density without a significant loss in the peak sharpness. The density of LLDPE was a decreasing function of mole fraction of α-olefin, and the decrease was more pronounced as the molecular weight of the incorporated α-olefin increased. However, when the density was plotted against weight fraction of α-olefin, a similar declining curve was observed irrespective of the type of α-olefins except the LLDPE made by the Z–N catalyst in which more α-olefin units were required to reach the same density as that of LLDPEs by (2-MeInd)2ZrCl2. LLDPE made by the Z–N catalyst had lower tensile strength but similar elongation and elastic modulus compared to those of poly(ethylene-co-1-dodecene) and poly(ethylene-co-1-octadecene) synthesized by (2-MeInd)2ZrCl2. Poly(ethylene-co-1-hexene) by (2-MeInd)2ZrCl2, however, exhibited lower elastic modulus and higher elongation compared with the other LLDPEs. Measurement of dynamic mechanical properties of LLDPEs revealed that β-transition peak appeared at a lower temperature and became more intense, as the density decreased, until the crystallinity of LLDPEs disappeared completely when the β-transition peak became fixed around −45°C. γ-transition was monitored at around −125°C and was thought to be induced by the limited motion of the main backbone chain.

Sonographic imaging of normal and osteoarthritic cartilage

This study was undertaken to describe representative sonographic features of normal and osteoarthritic cartilage. Sonographic evaluation was performed with real-time ultrasound equipment, using 7.5-, 10-, 13-, 15-, and 20-MHz transducers. Normal and osteoarthritic cartilage has been studied in healthy subjects and in patients with osteoarthritis. Ultrasonography allows a safe, quick, and careful evaluation of both normal and osteoarthritic cartilage. A spectrum of images ranging from loss of cartilage transparency to marked narrowing of the cartilage layer can be depicted clearly in patients with osteoarthritis. Loss of clarity of the cartilaginous band and loss of the normal sharpness of the synovial space-cartilage interface are the earlier features of cartilage damage. Although the value of ultrasonography in the evaluation of articular cartilage remains to be determined, this imaging method can be regarded as a useful bedside procedure for initial diagnostic screening of osteoarthritic femoral condylar cartilage.

Analysis of a Complex Gaseous Mixture by TG-MS and TG-FTIR

The thermal decomposition of sodium ethyl xanthate (SEX) was used to compare the techniques of pyrolysis-gas chromatography-mass spectrometry (py-GC-MS), thermogravimetry-Fourier transform infrared spectroscopy (TG-FTIR), and TG-MS. In the py-GC-MS analysis, SEX was pyrolysed at 400°C in an inert atmosphere. Major gases evolved were carbon disulfide, diethyl sulfide, ethanol, and carbonyl sulfide. The TG of SEX exhibited a sharp mass loss at 201°C (42.3%) and a gradual mass loss at 217-325°C (20.8 %). The MS spectra of the evolved gases were complex due to overlapping of molecular, isotope, and fragment ion signals. Using the MS in selected ion monitoring mode, the major gases evolved were found to be carbon disulfide and carbonyl sulfide. The FTIR spectra of the evolved gases displayed vibrational frequencies due to alkanes, carbonyls, carbonyl sulfide, and carbon disulfide. From the analyses it was concluded that py-GC-MS provided unambiguous gas identification. Interpretation of the MS results was reliant on the py-GC-MS results, and the FTIR data was limited to identifying gases with very characteristic vibration frequencies.

Biodiversity patterns in Indian Ocean corals, and effects of taxonomic error in data

Corals from 26 sites in the Indian Ocean, from numerous taxonomic sources, are analysed for distribution patterns after applying a consistent synonymy. The data set contains double the amount of distribution information used previously. Cluster analysis shows several contiguous regional groupings within this ocean, and no geographically dispersed groupings exist. Between-site species similarity correlates negatively with distance between sites. Coral species diversity and genus diversity plotted with latitude and longitude confirm that a band of high diversity stretches across the entire Indian Ocean, but that in this Ocean, unlike the Pacific and greater Caribbean area, there is no clear gradient with latitude at least up to the latitudinal limits of coral growth. About half the species are widespread throughout the Indian Ocean. Species frequency/distribution curves and cumulative frequency curves show that 150 species occur at only 2–4 sites. Multi-dimensional scaling (MDS) analysis using only these species confirms that they are important in forming sub-regional groupings which are superimposed on a general Indian Ocean homogeneity. The perennial problem of error in taxonomic data sets is examined. Increasing taxonomic error is introduced into the data using random methods. It is found that about 25% more error can be added to this data set before the relationship between similarity coefficient and geographical distance between pairs of sites is lost. Measures extracted from the clustering procedure using the original data and the data sets with added taxonomic error, show a sharp loss in cluster formation after addition of about 10 or 20% more error.