Search

The analytical solution of the bending problem for a clamped rectangular plate with a variable in-plane stiffness is found by using the method of superposition. The flexural rigidity of the plate varies across its width according to an exponential function. First, the analytical solution for a simply supported rectangular plate with a variable in-plane stiffness is obtained, and then the bending problem for the plate clamped at its four edges is solved analytically by the superposition of one simply supported plate under the transverse load and two simply supported plates under pure bending. The influence of the variable in-plane stiffness, aspect ratio, and different boundary conditions on the deflection and bending moment is studied by numerical examples. The analytical solution presented here may be helpful for the design of rectangular plates with a variable in-plane stiffness.

The wide field view (WFV) sensor on-board GF-1 satellite can acquire multi-spectral data with moderate spatial resolution, which holds great potential for monitoring the Earth's surface. This study assesses WFV data through cross-comparison of spectral band reflectances and vegetation indices with Landsat-7 Enhanced Thematic Mapper plus (ETM+) data. The four vegetation indices considered in this study are the normalized difference vegetation index (NDVI), the enhanced vegetation index (EVI), the ratio vegetation index (RVI), and the soil adjusted vegetation index (SAVI). The R2 between the WFV and ETM+ data were 0.82, 0.89, 0.92, and 0.80 for the blue, green, red, and near-infrared bands reflectance, and 0.90, 0.84, 0.83, and 0.91 for NDVI, EVI, RVI, and SAVI, respectively. The results displayed a high correlation between the spectral reflectances and vegetation indices of the two sensors’ data, which indicated the reliability of the WFV data. Furthermore, the WFV data were better than the ETM+ data with regards to spatial and temporal resolutions.

We present limits on spin-independent dark matter-nucleon interactions using a $10.6$ $\mathrm{g}$ Si athermal phonon detector with a baseline energy resolution of $\sigma_E=3.86 \pm 0.04$ $(\mathrm{stat.})^{+0.19}_{-0.00}$ $(\mathrm{syst.})$ $\mathrm{eV}$. This exclusion analysis sets the most stringent dark matter-nucleon scattering cross-section limits achieved by a cryogenic detector for dark matter particle masses from $93$ to $140$ $\mathrm{MeV}/c^2$, with a raw exposure of $9.9$ $\mathrm{g}\cdot\mathrm{d}$ acquired at an above-ground facility. This work illustrates the scientific potential of detectors with athermal phonon sensors with eV-scale energy resolution for future dark matter searches., Comment: 7 pages, 4 figures, this version includes ancillary files from official data release

To enlarge the interaction structure to a feasible dimension and to decrease the required magnetic field to an available strength, the gyrotron devices at THz frequencies must be designed with a high-order-mode interaction, which is weaker in a beam–wave interaction and more susceptible to mode competition. Using the same interaction structure (a circular waveguide) as in the gyrotron traveling-wave amplifier (gyro-TWT), but replacing the axial magnetic field of the gyro-TWT with a tapered helical magnetic field, we found that the gyrating electrons are able to perform strong interaction with the TE11 mode in the THz region. Through an example case, we explored the behavior of the particles and wave fields as in a beam–wave interaction under a modified scheme of the gyro-TWT with a numerical simulation code. The equations required for the simulation are presented. The simulation result of the example case indicates that, through the TE11 beam–wave interaction under the presented scheme, more than one quarter of the beam energy can be converted to the wave at 612.7 GHz and to heat, dissipated on the waveguide wall, of radius 2.5 cm.

Solid-state for high power RF application is an attracting and interesting technology which is now become popular in accelerator field. To adopt and master such technique, a 500MHz, 80kW solid-state amplifier is thus developed in NSRRC. The amplifier is consisted of 100 900W amplifier modules which are driving by identical modules. Each module contains input and output directional couplers and status monitoring circuits. To have longer life time and better performance, the RF power transistors are integrated with water cooled heat sink directly. In such a way, the transistors have higher output power and better efficiency. The RF power of each module is combined through coaxial combiner while its DC power is provided by parallel connected DC power supplies which can provide better redundancy and reliability. The home-made solid-state amplifier is demonstrated to have quite high quality RF power and reliability with acceptable power combination efficiency.

A proper cryogenic environment is essential for the operation of superconducting devices. A test area for the superconducting radio-frequency modules (SRF) has been established in the RF laboratory at National Synchrotron Radiation Research Center in Taiwan; these modules require much liquid helium during conditioning and performance tests; a cooling capacity of 120 W is expected for the acceptance test of the SRF module. The cryogenic environment of the test area is completed on transferring the liquid helium over a remarkable length of 205 m from the two cryogenic plants at Taiwan Light Source, with a valve box located at each end to control and to measure the cryogenic flow. Flexible cryogenic transfer lines of concentric four-tube type are chosen for both the supply of liquid helium and the return of cold helium gas. Functional examination of this long transfer system was first achieved with a 500-L Dewar in the radio-frequency laboratory; an SRF module was then installed in the test area for practical operation. The primary concern about the cryogenic transfer system is the heat loss; a measurement technique based on the principle of thermodynamics is developed and proposed herein. With the available sensors inside the valve boxes and the heaters inside the 500-L Dewar and the test SRF module, this technique has proved promissing from the measured results.

Background Establishing a stand-alone cryogenic test stand is of vital importance to ensure the highly reliable and available operation of superconducting radio-frequency module in a synchrotron light source. Operating a cryogenic test stand relies strongly on a capability to deliver two-phase helium along long cryogenic transfer lines. A newly constructed cryogenic test stand with flexible cryogenic transfer lines of length 220 m at National Synchrotron Radiation Research Center is required to support a superconducting radio-frequency module operated at 126.0 kPa with a 40-W dynamic load for a long-term reliability test over weeks. It is designed based on a simple analytical approach with the introduction of a so-called tolerance factor that serves to estimate the pressure drops in transferring a two-phase helium flow with a substantial transfer cryogenic heat load. Tolerance factor 1.5 is adopted based on safety factor 1.5 commonly applied in cryogenic designs to estimate the total mass flow rate of liquid helium demanded. A maximum 60-W dynamic load is verified with experiment measured with heater power 60 W instead after the cryogenic test stand has been installed. Results Aligning the modeled cryogenic accumulated static heat load with the results measured in situ, actual tolerance factor 1.287 is obtained. The feasibility and validity of our simple analytical approach with actual tolerance factor 1.287 have been scrutinized by using five test cases with varied operating conditions. Calculated results show the discrepancies of the pressure drops between the estimated and measured values for both liquid helium and cold gaseous helium transfer lines have an underestimate 0.11 kPa and an overestimate 0.09 kPa, respectively. A discrepancy is foreseen, but remains acceptable for engineering applications from a practical point of view. Conclusions The simple analytical approach with the introduction of a tolerance factor can provide not only insight into optimizing the choice of each lossy cryogenic piping element of the transfer lines in the design phase but also firm guidance for upgrading the present cryogenic transfer lines for its subsequent application.

Objective To report our experience in the management of catecholaminergic polymorphic ventricular tachycardia in Hong Kong Chinese children. Methods This case series study was conducted in a tertiary paediatric cardiology centre in Hong Kong. All paediatric patients diagnosed at our centre with catecholaminergic polymorphic ventricular tachycardia from January 2008 to October 2014 were included. Results Ten patients (five females and five males) were identified. The mean age at presentation and at diagnosis were 11.0 (standard deviation, 2.9) years and 12.5 (2.8) years, respectively. The mean delay time from first presentation to diagnosis was 1.5 (standard deviation, 1.3) years. They presented with recurrent syncope and six patients had a history of aborted cardiac arrest. Four patients were initially misdiagnosed to have epilepsy. Catecholaminergic polymorphic ventricular tachycardia was diagnosed by electrocardiogram at cardiac arrest (n=2), or provocation test, either by catecholamine infusion test (n=6) or exercise test (n=2). Mutations of the RyR2 gene were confirmed in six patients. Nine patients were commenced on beta-blockers after diagnosis. Despite medications, three patients developed aborted or resuscitated cardiac arrest (n=2) and syncope (n=1). Left cardiac sympathetic denervation was performed in five patients and an implantable cardioverter defibrillator was implanted in another. There was no mortality during follow-up. Conclusions Catecholaminergic polymorphic ventricular tachycardia should be considered in children who present with recurrent syncope during exercise or emotional stress. Despite beta-blocker treatment, recurrent ventricular arrhythmias occur and may result in cardiac arrest.

SUMMARY— Malonaldehyde was shown to react with bovine plasma albumin under aqueous conditions by a pH-dependent reaction exhibiting first-order kinetics. The maximum reaction rate observed was near pH 4.30. The reaction was shown to involve the e-amino lysine and N-terminal amino aspartic acid groups on the protein as judged by their loss to reaction with 1-fluoro-2,4-dinitrobenzene. Malonaldehyde did not appear to participate in an intermolecular cross-linking reaction with gelatin sols over a wide pH range. Presumptive evidence was obtained for the reaction of malonaldehyde, derived from autoxidized lipid, with the c-amino lysine functions on bovine plasma albumin. A nucleophilic 1,4-addition of the free amino functions on the protein to the end carbon atom of the α,β-unsaturated carbonyl system of the free enol of malonaldehyde to form an enamine linkage is postulated to be the mechanism for this reaction.

BACKGROUND AND PURPOSE: The purpose of this study was to investigate the risk factors for new symptomatic vertebral compression fractures after vertebroplasty at the thoracolumbar junction. MATERIALS AND METHODS: We conducted a retrospective analysis of 53 patients treated with percutaneous vertebroplasty at the thoracolumbar junction (T12, L1). The follow-up period was 15–27 months. The occurrence of new symptomatic vertebral compression fractures was recorded after vertebroplasty. We evaluated patient age and sex, amount of injected cement, vacuum clefts in the collapsed bodies, initial wedge angle of the compression fracture, change of the wedge angle after vertebroplasty, intradiskal cement leak, and percentage of height restoration of the vertebral body. In this report, we surveyed the possible risk factors for new symptomatic vertebral compression fractures. RESULTS: Thirty-nine (74%) of the 53 patients had fluid and/or air in the compression fracture at the thoracolumbar junction (T12, L1). Eight (20.5%) of the 39 patients with vacuum clefts had new symptomatic compression fracture after vertebroplasty between 1 month and 4 days after surgery to 23 months and 4 days after surgery. The patients with new symptomatic compression fracture had higher initial wedge angle and wedge angle change (more than 7°) after vertebroplasty than those without fractures; these data were considered statistically significant. CONCLUSIONS: The incidence of vacuum clefts in the compression fracture at the thoracolumbar junction is high (74%). The severity of initial wedge angle and wedge angle change affects the incidence of new symptomatic compression fracture.

Tris(8-hydroxyquinolato) aluminum ( Alq 3), a prototypical molecule for organic light-emitting devices, has been studied via synchrotron radiation photoemission to investigate (1) the surface electronic structure of the molecules at room temperature and at elevated temperatures, (2) adsorption onto the inorganic Si (001)-2×1 surface, and (3) doping with the alkaline metal Mg . For case (1), three chemical environments of carbon are resolved. Moreover, the shake-up satellite structures are detected in all the N 1s, C 1s, O 1s, and Al 2p core-level spectra, but with different magnitudes. Annealing allows for a charge redistribution within Alq 3 itself. As to case (2), the organic molecules not only passivate the dangling bonds, but also rupture the dimer bonds. The wave function of the surface dangling bonds and of the pyridyl side of an 8-quinolinol ligand overlaps greatly so that charge is polarized towards, the organic adlayer. However, the polarization diminishes at greater coverage. With regard to case (3), the N 1s core-level spectra appear as an Mg -induced charge-transfer component with a binding energy lower than the original component. This new component grows gradually in intensity with increasing concentration of the dopant. Moreover, Mg also affects the O 1s core, as manifested by a component lying at a +1.09 eV higher binding energy than the original component. The Mg 2p core-level spectra, although rather broad, exhibit a shift toward a lower binding energy with increasing Mg vapor. Upon examining all these experimental results, we propose that Mg in the surface Alq 3 molecules forms clusters. Each cluster attaches to a pyridyl ring, affecting not only the nitrogen atom at that ring, but also the oxygen atom in the adjacent phenoxide ring. The depleted charge in the affected oxygen then flows about its adherent ligand and resides on the pyridyl ring at that ligand, resulting in a high Alq 3 anion state.

P&O algorithm is one of the most common used MPPT tracking techniques in the Photovoltaic (PV) systems due to its simple structure, less use of parameters and easy implementation. Traditional Perturbation and Observation (P&O) MPPT algorithm (Tavares et al. 2009) used a fixed step size to track the Maximum Power Point (MPP) during the perturbation period. The step size of perturbation is decided by the needs of tracking speed and steady state oscillations. When a larger perturbation step size is chose, a faster tracking speed can be obtained. However, larger oscillations will be generated near the MPP and cause significant power losses. Conversely, to use a smaller perturbation step size can reduce the power oscillations and losses, but also the tracking speed. To solve this problem, a modified P&O MPPT algorithm is proposed to use a variable step size technique to perturb and track the MPP of the PV systems. When the operating point of PV modules is far away from the MPP, the system will automatically increase the perturbation step size to reinforce the tracking speed. When the operating point is close to the MPP, the system will also automatically reduce the perturbation step size to a certain extent in order to reduce power oscillations and losses.

We study a lattice model of an interacting uniform self-avoiding star polymer with f branches. A 1/d -expansion for the limiting reduced free energy is derived through order 1/d for general f and, for f = 3, to order 1/d 2 . The terms in the expansion are independent of f and agree term by term with the corresponding expansion for interacting self-avoiding walks. We also present a miscellany of numerical results obtained by more conventional series and Monte Carlo techniques. All our results, both past and present, support the conjecture that the limiting reduced free energies of f -stars, walks and polygons are identical for all values of the interaction parameter .

A semipurified test diet containing 1% linolenate as the sole dietary essential fatty acid was fed to a group of rainbow trout (Salmo gairdneri) for 34 months. The fish matured and the eggs produced were hatched. The second generation fry were fed our laboratory diet for 3 months. The growth of these fry was normal. Histologic examinations revealed no abnormality in liver, heart and kidney tissues of the fry during the three month period.

We consider uniform star polymers on a variety of lattices, with an additional contact interaction between pairs of vertices which are unit distance apart and are not joined by an edge of the star. We present some rigorous results and other evidence which indicate that these systems have the same limiting free energy as self-interacting self-avoiding walks. We discuss the extension of these results to other homeomorphism types and to systems with an additional surface interaction term.

We have employed synchrotron radiation photoemission to investigate the tris(8-hydroxyquinolato) aluminum (Alq3) molecules adsorbed on an inorganic Si(001)-2×1 surface at room temperature. The surface-related valence states associated with the dimers and backbonds lying a couple of eV below the Fermi level reduce in strength upon Alq3 adsorption, indicating that the organic molecules not only passivate the dangling bonds but also rupture the dimer bonds. The wave function of the surface dangling bonds and of the pyridyl side of an 8-quinolinol ligand overlaps greatly so that charge is polarized toward the organic adlayer, resulting in the appearance of low-energy components in both N 1s and C 1s core-level spectra, which is similar to the case of Mg-doped Alq3. However, the polarization diminishes at greater coverage, in which case both 1s cores behave as in the nominal states.

A superconducting radio-frequency (SRF) module is commonly used for a high-energy accelerator; its purpose is to provide energy to the particle beam. Because of the low power dissipation and smaller impedance of a higher-order mode for this module, it can provide more power to the particle beam with better stability through decreasing the couple bunch instability. A RF coupler is necessary to transfer the high power from a RF generator to the cavity. A coupler of coaxial type is a common choice. With high-power operation, it might suffer from multipacting, which is a resonance phenomenon due to re-emission of secondary electrons. Applying a bias voltage between inner and outer conductors of the coaxial coupler might increase or decrease the strength of the multipacting effect. We studied the effect of a bias voltage on multipacting using numerical simulation to track the motion of the electrons. The simulation results and an application for SRF operation with a large beam current are presented in this paper.

The term "human papillomavirus" has been used as the keyword during searching titles, abstracts, and keywords based on the online version of Science Citation Index (SCI), Web of Science from 1993 to 2008. Twelve document types were found among the 14,943 papers published in 1,072 journals that were listed in 99 SCI subject categories. All the articles referring to human papillomavirus were assessed by using the following aspects: characteristics of publication output, distribution of output in journals, publication output of source country, source institute, and analysis of word clusters in title, author keywords, and keywords plus. The results have shown that the USA ranked first using five publication indicators including total, single country, international, first author, and corresponding author publications. China has had the sharpest rise of publications since 2004. The top four European countries in 2008 were France, Germany, the UK, and Italy, respectively. Trend studies with word cluster analysis were performed with regards to the areas of immunology, screening methodology, behavioral sciences, economics, and meta-analysis. All those areas have shown a sharp upward rise since 2004. In addition, hypermethylation-induced inactivation of the p16 gene in the early stages of oncogenesis has been getting more interest in recent years.

(BrXP-50), was conducted. Morphological analyses and mechanical tests were combined to evaluate the toughening mechanisms of modified PA-6 and the fracture mechanism of unmodified PA-6. We conclude that the fracture mechanism of unmodified PA-6 in the impact test is crazing-cracking under the dilatational stress created by the plastic constraint, while that of the BrXP-50 elastomer modified PA-6 is plastic tearing limited by the ultimate tensile strain. Cavitation of BrXP-50 elastomer particles occurred in the impact test, and is proposed as a controlling step in toughening: it relieves the plastic constraint so that the cracking process is postponed and additional plastic deformation can occur, leading to higher impact toughness.

Particle swarm optimization (PSO) algorithm is a heuristic global optimization technology based on colony intelligence. For improving the searching ability of this algorithm, a search factor is added into the movement of the particle to develop it, and the developed PSO algorithm is used for optimal design of water-supply pipe network. Reliability constraint, which is based on the principle of average distribution flux, is added into the process of optimal design to avoid producing tree pipe network for the reason of economic flux distribution. The algorithm is applied to a simple test network. Comparison with the results of basic PSO algorithm shows that the developed algorithm has stronger global optimizing ability and better search accuracy for optimal design of water-supply pipe network.

Selected values are gathered for the crystalline compounds HgTe, CdTe, and ZnTe and their elements. Then the phase diagram and remaining thermodynamic data for these binaries and the Hg-Cd-Te, Hg-Zn-Te,and Cd-Zn-Te ternaries are fit with an associated solution model for the liquid phase anda quasiregular model for the pseudobinaries. Finally, no adjustable model parameters remaining, some features of the Hg-Cd-Zn-Te quaternary are calculated.

We have employed synchrotron radiation photoemission to investigate the electronic structure of tris(8-hydroxyquinolato) aluminum $({\mathrm{Alq}}_{3})$ at room temperature as well as at elevated temperatures. The dependence of the molecular state cross sections on the photon energy is demonstrated. Three chemical environments of carbon are resolved, accompanied with at least two shake-up satellite structures. Small loss structures are detected in other N $1s$, O $1s$, and Al $2p$ core-level spectra, but with various magnitudes. Annealing produces charge redistribution of the molecular states within ${\mathrm{Alq}}_{3}$ itself. ${\mathrm{Alq}}_{3}$ is stable at high temperature.

Synchrotron radiation photoemission was used to investigate the electronic structure of magnesium deposited on tris(8-hydroxyquinolato) aluminum $(\mathrm{Al}{q}_{3})$ with the film thickness from one molecular layer to a thick solid. In a monolayer-thick $\mathrm{Al}{q}_{3}$ on the $\mathrm{Si}(001)\text{\ensuremath{-}}2\ifmmode\times\else\texttimes\fi{}1$ surface, the organic molecules accept from the charge at the surface dimers. However, as Mg is deposited on top of this thin $\mathrm{Al}{q}_{3}$ film, the surface dimers underneath the film start to show reacted magnesium silicide, indicating clearly a prompt diffusion of Mg through $\mathrm{Al}{q}_{3}$. In regard to the $\mathrm{Al}{q}_{3}$ solid, the highest occupied molecular orbital of $\mathrm{Al}{q}_{3}$ shifts monotonically towards high binding energy, and the lowest unoccupied molecular orbital remains fixed in energy with increasing Mg concentration. The N $1s$ core appears an Mg-induced charge-transfer component with a binding energy lower than the original component. This new component grows gradually in intensity with increasing concentration of the dopant. Its energy separation from the original component is $\ensuremath{-}1.51\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ at small exposure, but widened up to $\ensuremath{-}1.85\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ at large coverages. Moreover, Mg also affects the O $1s$ core as manifested by a components lying at $+1.09\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ higher binding energy than the original component. The Mg $2p$ core-level spectra, although rather broad, exhibit a shift towards lower binding energy with increasing Mg vapor. All these experimental evidences suggest that magnesium organometallic complex residing in the surface exhibits an electronic structure differently from the bulk. We propose that Mg in the surface $\mathrm{Al}{q}_{3}$ molecules forms actually clusters. It attaches to a pyridyl ring, affecting not only the nitrogen atom at that ring, but the oxygen atom in the adjacent phenoxide ring. The depleted charge in the affected oxygen flows then about its adherent ligand and resides on the pyridyl ring at that ligand, resulting in a high $\mathrm{Al}{q}_{3}$ anion state.

A new architecture of the sigma-dela modulators using a chopper-stabilized configuration is described. It is shown that using this new architecture and without any other circuit techniques, a sigma-delta modulator becomes immune from the contamination of the inherent low-frequency noise, such as offset noise, flicker noise, and clock feedthrough noise. The new architecture can be easily designed from the existing architectures without any stability problems. As an example, a second-order sigma-delta modulator is designed by using the new architecture. The simulation results show excellent immunity from the low-frequency noise. >

The paper describes an object-oriented system that smoothly integrates procedural function invocation and declarative rule reasoning into a single homogeneous system. This allows efficient computations expressed as external functions to be incorporated into rule systems to improve computational efficiency and extensibility of intelligent systems. We first discuss the differences between declarative rules and procedural functions. We then describe an object-oriented model that incorporates both of these. The model has a translation phase and an execution phase. We also discuss problems arising from the different ways that data are represented (terms in rules vs. data objects in functions), from the existence of user-defined types in functions and the necessary argumentations to the unification process in the rule system. >

Heel pain or calcaneodynia is a common clinical complaint which has a myriad of causes ranging from plantar fasciitis to stress fracture. In many instances, the etiology of the heel pain is difficult to ascertain simply on the basis of history and physical examination. Therefore, the clinician may enlist various diagnostic imaging modalities to clarify the source of pain. Of all the imaging techniques, magnetic resonance imaging (MRI) has proven its worth in the diagnosis of heel pain. This article outlines the various causes of heel pain and their associated imaging findings.

A new test of peripheral color contrast is described. A high-definition color monitor driven by a personal computer with a graphics interface card displays an annulus subtending 25 degrees at the eye. The color contrast between the annulus and the background can be varied. Forty-five degrees of the annulus is randomly removed in one of four quadrants. Patients are asked to identify the position of the gap while fixating a central spot. The minimum color contrast between annulus and background at which the identification is possible is between 13-16% for the protan, deuteran, and tritan axis in normal subjects. This threshold value changes little with age, refractive error, or pupillary aperture, and test-retest variability is low. Testing one eye takes only 1-2 min. The test was applied to ocular-hypertensive and glaucomatous patients. All patients with glaucoma had thresholds greater than two standard deviations (SD) above the normal mean. In addition, 97% of glaucoma patients had thresholds greater than four SDs, and 95% had thresholds more than five SDs above the normal mean. Most patients with ocular hypertension and clinical signs indicating a low or medium risk of conversion to glaucoma had thresholds under the upper limit of normal. High-risk patients with ocular hypertension fell into two groups. One approximated to normal; the other had elevated thresholds, which in many cases were more than four SDs above the normal mean. The epidemiologic consequences of this test are discussed.

Arguments are given favoring values for the high temperature heat capacity and Gibbs energy of formation of CdTe that are different from those we used previously. Based on these, the quaternary phase diagram has been reanalyzed. The changes are discussed and the new associated liquid phase model parameters given.

Four experimental diets containing different proportions of beef tallow and salmon oil were prepared. Each diet was fed to triplicate groups of juvenile coho salmon (Oncorhynchus kisutch) for 14 wk. The final fish weight was greatest with a diet containing 8% each of tallow and salmon oil. Fatty acid analysis indicated that the dietary salmon oil provided adequate quantities of the ω3 fatty acids required by the coho salmon. Fish body lipid saturation increased only slightly as the concentration of tallow in the diet increased. Beef tallow was found to be a good source of dietary energy when used in conjunction with a fish oil rich in ω3 fatty acids.Key words: beef tallow as source of dietary energy, coho salmon (Oncorhynchus kisutch), growth, feed efficiency, body lipid composition

Nine diets, each containing different levels of linoleic acid (18:2 omega 6) and linolenic (18:3 omega 3) were fed to duplicate groups of rainbow trout for 14 weeks. The growth rate, feed efficiency, accumulated mortality, and fatty acid composition of neutral fat and phospholipids of these groups of fish were determined. The growth was slow in the groups of fish receiving diets containing (A) low concentration of 18:3 omega 3and (B) high concentration (5%) of 18:2 omega 6. The accumulated mortality was high in these groups of fish. The diet containing 1% of 18:3 omega 3 alone supported rapid fish growth with low mortality . The feed efficiency of this diet was also high. The metabolism of 18:2 omega 6 and 18:3 omega 3 in fish and their conversion to more unsaturated fatty acids typical of fish lipids was investigated.

The validity of the 2-thiobarbituric acid (TBA) procedure for the measurement of oxidative rancidity by the determination of malonaldehyde (MA) as the red pigment with an absorption max at 532 mµ has been questioned [J. Am. Oil Chem. Soc.39, 34 (1962)]. Side reactions were reported to occur yielding degradation of TBA to products which absorb at the same wave length as the TBA-MA complex and at 450 mµ.

Rheological behavior of dispersed two-phase polymer melts has been investigated by means of a capillary rheometer. The two-phase systems chosen for study were blends of two polymers: high-density polyethylene and polystyrene, which are incompatible in the molten state. In order to investigate the state of dispersion, photographs were taken of the microstructure of extrudate samples, showing that the polystyrene forms long fibers or droplets as a discrete phase dispersed in the polyethylene which forms a continuous phase. Measurements were made of the axial pressure distributions of the two-phase molten polymers flowing through circular tubes, which permit one, according to the theory advanced by Han, to determine viscous and elastic properties of the melts. Also measured was melt die swell ratio. It has been found from the two independent experimental techniques that there exist a maximum and/or minimum elastic property at a certain blending ratio, and that the elastic property decreases first with L/D ratio of a capillary and then levels off.

Measurements were taken of both viscous and elastic properties of polystyrene melts, using a capillary rheometer recently constructed byHan. The viscous property is determined from the slope of the axial pressure distribution, and the elastic property is determined from the exit pressure, which is obtained at the tube exit when the straight line portion of the axial pressure profile is extrapolated to the exit of the tube. Previous studies ofHan demonstrated that the exit pressure thus obtained can be correlated with die swell ratios, and that the exit pressure is equal to the normal stress difference for polymer melts in fully developed viscometric flow. The present study of polystyrene melts corroborates all previous correlations obtained with high density polyethylene and polypropylene melts as regard the exit pressure measurements. A salient feature of the method employed here is that it requires only a single capillary, long enough to assure that flow is fully developed.

The propaganda policy of Communist leaders in China today is based on the theory that economic reforms must be accompanied by a political indoctrination program which stimulates mass action against “enemies,” both internal and external. Procedures are controlled by a powerful propaganda machine.

We investigated the growth of rainbow trout (Salmo gairdneri) fed diets containing an animal fat (lard) as a source of energy. Nine diets, identical in gross energy, but containing three levels of protein, were each fed to duplicate groups offish for 14 weeks. The control diets contained 22% herring oil; in the test diets, 33 and 50% of the dietary herring oil was replaced by lard. The final fish weight, feed consumption, feed efficiency, and fish liver size were about the same in the groups offish receiving control and test diets containing the same protein level.