bluuebunny/crossref_metadata_2025 huggingface dataset:
Ribes host range and erratic distribution within plants of blackcurrant reversion associated virus provide further evidence for its role as the causal agent of reversion disease
Authors: LATVALA SATU , SUSI PETRI , LEMMETTY ANNE , COX SARAH , JONES A TEIFION , LEHTO KIRSI
Published: February 2008

Reversion is the most important disease of blackcurrant crops world‐wide yet, despite research over more than 70 yr, the causal agent of this disease has not been identified. We reported recently the isolation of a new virus from reverted blackcurrant which had a very close association with the two recognised forms of blackcurrant reversion disease, and was detected in vector gall mites from reverted plants and in plants on which such mites had fed (Lemmetty et al., 1997). These data suggest that this virus, tentatively called blackcurrant reversion associated virus (BRAV), may be the causal agent of reversion disease. We now report the detection of BRAV by immuno‐capture reverse‐transcriptase PCR (IC‐RT‐PCR) in redcurrant and in the wild species, Ribes spicatum and R. alpinum, other known hosts of the reversion agent, but not in the non‐host, gooseberry, graft‐inoculated with scions from reverted blackcurrant plants. We also demonstrate the erratic distribution of BRAV in reversion‐affected blackcurrant plants, another characteristic of the reversion agent. Taken together with our earlier findings, these new data add further support to the suggestion that BRAV is the causal agent of reversion disease. We also report how changes to the various parameters of sample preparation and of the IC‐RT‐PCR protocol affect the sensitivity of BRAV detection.
Toxicity of anethole and its effects on egg production of Ceratitis capitata Wied. (Dipt., tephritidae)
Authors: BAZZONI EMANUELA , PASSINO GIOVANNI SANNA , MORETTI MARIO D L , PROTA ROMOLO
Published: February 2008

We report the effects of anethole on adult Ceratitis capitata Wied. (Diptera, Tephritidae) which cause serious damage to fruit crops. Because of the toxicological and environmental pollution due to the indiscriminate use of organophosphates against the endophagous larvae, the control of this pest is now mainly directed against the adults, by the application of bait sprays. Considerable toxic effects have been obtained by oral administration to adults of nutritive formulations containing 5% anethole with some hydrolised commercial proteins. In this test we observed high values of mortality (85% after 24 h) and a total inhibition of reproductive activity. The toxic effect produced by oral administration of the compound tested appears to be correlated to irreversible damage to the gut of the medfly.

These results acquire a particular importance in view of the introduction of alternative methods for the control of the medfly. In particular, our objective is the testing of relevant formulations of this active principle in field. The use of anethole combined with protein baits, which can be used in the open field, is therefore particularly promising.
Detection and differentiation of African coconut phytoplasmas: RFLP analysis of PCR‐amplified 16S rDNA and DNA hybridisation
Authors: TYMON A M. , JONES P. , HARRISON N A.
Published: February 2008

Phytoplasmas associated with lethal decline diseases of the coconut palm (Cocos nucifera) in west and east Africa were detected by the specific amplification of their 16S rRNA genes. The primers used were based on conserved mollicute‐specific and coconut‐phytoplasma 16S rRNA gene sequences. Phytoplasma 16S rDNA was amplified from all African decline affected palms, some periwinkle maintained phytoplasmas, but not from healthy palms, infected palms from Florida or from the Cocos spiroplasma and Acholeplasma sp. mollicutes. African phytoplasmas were also detected by DNA hybridisation using two probes from the palm lethal yellowing phytoplasma from Florida. Probes hybridised at moderate stringency to dot blots of lethal decline affected palms from Africa, indicating possible genetic relationships between different coconut phytoplasmas. RFLP analysis of rDNA fragments (length c. 1.45 kbp) detected polymorphisms, indicating that the pathogens found in west and east Africa are not identical. This provides a useful tool for further epidemiological studies of African coconut phytoplasmal diseases.
An empirical method for describing the joint effects of environmental and other variables on crop yield
Authors: LARK R M.
Published: February 2008

There is considerable interest in developing understanding of the spatial variation of crop yield within fields in relation to the spatial variation of environmental factors. Such understanding might allow inputs to crops to be used more efficiently by spatially variable application. The joint action of factors on crop yield (whether controlled treatments or environmental variables) may be additive, interactive or potentially limiting in the sense of von Liebig's “Law of the Minimum”. The nature of the joint action of an input and environmental factors has profound implications for the possibility of improving the efficiency of use of the input by spatially variable application. Conventional methods for analysing data on such factors and yield (e.g. multiple regression) make specific assumptions compatible only with a narrow range of permissible models. A procedure is proposed and demonstrated in this paper for the exploratory analysis of data from experiments and/or crop surveys in order to describe the joint action of important factors on crop yield. The procedure could be applied to specific experiments in order to indicate whether there is any scope for optimising rates of an input with respect to one or more spatially variable factors, and for indicating whether the relationship between the local optimum rate of the input and values of these factors is simple (factors act additively or in accordance with the Law of the Minimum) or complex (factors interact).
Genetic studies on seedling vigour in sesame
Authors: MPONDA O K K. , MORSE S. , GIBBON D. , ARTHUR A E.
Published: February 2008

Genetic studies were carried out on seedling and agronomic characters amongst 50 sesame genotypes to estimate the genetic variation, determine the relationships amongst the characters and identify rapidly growing genotypes with vigorous seedling growth. The contribution of genetic variance was highest for the two mature characters, days to first flower (95.6%) and number of nodes to first flower (95.2%), and was medium/high (50–75%) for most of the seedling characters. Strong positive genetic correlations were obtained between various cotyledon and early leaf characteristics measured at 20 days after sowing. Based on these results several genotypes were identified as having rapid seedling growth and these could form an initial gene pool to provide material for screening for tolerance to sesame flea beetle.
Resistance of tomato infected with cucumber mosaic virus satellite RNA to potato spindle tuber viroid
Authors: YANG XICAI , KANG LIANGYI , TIEN PO
Published: February 2008

Tomato (Lycopersicon esculentum cvs Rutgers and Lichun) plants were firstly pre‐inoculated either with a cucumber mosaic virus (CMV) isolate containing satellite RNA (CMV‐S52) or with a CMV isolate without satellite RNA, and then challenged 14 days later with a severe strain of potato spindle tuber viroid (PSTVd). Also, tomato plants transformed with CMV satellite cDNA and non‐transgenic control plants were directly inoculated with PSTVd. Protection effects were assessed by the observation of symptoms and by assay of PSTVd accumulation in tomato plants using return polyacrylamide gel electrophoresis and silver staining. The results indicated that the satellite‐transgenic plants and plants pre‐inoculated with CMV‐S52 showed much milder symptoms of PSTVd infection than the respective control plants. The concentration of PSTVd RNA in the satellite‐transgenic plants and CMV‐S52 pre‐inoculated plants was reduced to about 0.02‐0.03 of the controls. PSTVd infection did not increase the amount of satellite ds‐RNA in plants. It is concluded that the plant resistance to PSTVd is induced by the presence of satellite RNA rather than the CMV infection. It is suggested that as there is considerable sequence similarity between satellite RNA and PSTVd, base pairings may be a cause of reduction of both symptoms and the accumulation of PSTVd.
Diversity in greengram (Vigna radiata (L.) Wilczek) germplasm collection and its potential use in crop improvement
Authors: BISHT I S , MAHAJAN R K , KAWALKAR T G
Published: February 2008

Greengram or mungbean (Vigna radiata (L.) Wilczek), which originated in the Indian sub‐continent, is an important pulse crop in India. Genetic diversity and patterns of variation among 111 accessions representing the better agronomic types from the entire collection of the National Bureau of Plant Genetic Resources were studied. Wide variation in morphological and agronomic traits viz. number of pods per plant, yield per plant, 100‐seed weight, fruit setting capacity, flowering period, maturity, number of pod bearing peduncles, plant height, number of primary branches, length of branch, nodulation and leafiness was observed. Grain yield was found to be significantly correlated with 100‐seed weight and pod length. The data were subjected to cluster and principal components analysis. The accessions were grouped into six discrete and well‐defined clusters. The study demonstrated the patterns of variation at the population level. The multivariate analysis was useful in identifying a group of accessions with yield enhancing traits within a highly diverse group of accessions and their potential value in greengram improvement is suggested.
Effects of light leaf spot (Pyrenopeziza brassicae) on yield of winter oilseed rape (Brassica napus)
Authors: SU H. , FITT B D L , WELHAM S J , SANSFORD C E , SUTHERLAND K G
Published: February 2008

The relationship between development of light leaf spot and yield loss in winter oilseed rape was analysed, initially using data from three experiments at sites near Aberdeen in Scotland in the seasons 1991/92, 1992/93 and 1993/94, respectively. Over the three seasons, single‐point models relating yield to light leaf spot incidence (% plants with leaves with light leaf spot) at GS 3.3 (flower buds visible) generally accounted for more of the variance than single‐point models at earlier or later growth stages. Only in 1992/93, when a severe light leaf spot epidemic developed on leaves early in the season, did the single‐point model for disease severity on leaves at GS 3.5/4.0 account for more of the variance than that for disease incidence at GS 3.3. In 1991/92 and 1992/3, when reasonably severe epidemics developed on stems, the single‐point model for light leaf spot incidence (stems) at GS 6.3 accounted for as much of the variance. Two‐point (disease severity at GS 3.3 and GS 4.0) and AUDPC models (disease incidence/severity) accounted for more of the variance than the single‐point model based on disease incidence at GS 3.3 in 1992/93 but not in the other two seasons. Therefore, a simple model using the light leaf spot incidence at GS 3.3 (x) as the explanatory variable was selected as a predictive model to estimate % yield loss (yr):yr= 0.32x– 0.57. This model fitted all three data sets from Scotland, When data sets from Rothamsted, Rosemaund and Thurloxton in England were used to test it, this single‐point predictive model generally fitted the data well, except when yield loss was clearly not related to occurrence of light leaf spot. However, the regression lines relating observed yield loss to light leaf spot incidence at GS 3.3 often had smaller slopes than the line produce, by the model based on Scottish data.
Comparison of natural and artificial epidemics of take‐all in sequences of winter wheat crops
Authors: BATEMAN G. L. , HORNBY D.
Published: February 2008

Winter wheat was grown for six successive years (Expt 1) and for three successive years (Expt 2) in field experiments on different soil types. Artificial inoculum of the take‐all fungus (Gaeumannomyces graminisvar.triticicultured on autoclaved oat grains) was incorporated in the soil of some of the plots just before, or at, sowing of the first winter wheat crop. Expt 1 tested the incorporation of similar amounts of inoculum (212 kg ha‐1) at different depths. Expt 2 tested different amounts of inoculum at the same, shallow depth. Early sowing (September), late sowing (October) and spring inoculation were additional treatments, applied to the first crop only, in Expt 2.

Seasonal factors apart, the disease outcome in the first year after inoculation depended on amounts and placement of applied inoculum, as well as date of sowing. Deeper inoculum resulted in less disease (Expt 1). Severe take‐all was produced in Expt 2 by incorporating inoculum shallowly in sufficient quantities (400 kg ha‐1or more). Less inoculum (200 kg ha‐1) generated less disease, especially in earlier‐sown plots. Differences in disease amongst inoculum treatments were greatest in the first year and diminished subsequently, particularly where sowing had been early in the first year.

In Expt 1, where first crops exposed to artificial inoculum developed moderate‐to‐severe disease, disease in subsequent second and/or third crops was less. In the fourth crop a second peak of disease occurred, coinciding with a first peak in sequences without added inoculum. Take‐all decline (TAD) appeared to be expressed in all sequences thereafter. In Expt 2 in sequences without added inoculum, TAD occurred after a peak of disease in the second crop. Where 400 kg ha‐1or more of inoculum were added, disease was severe in the first year and decreased progressively in successive years. Disease was less patchy in plots that received artificial inoculum. However, it remains uncertain mat severe disease caused by artificial inoculation achieved an early onset of true TAD.

The infectivity of the top 12 cm of soil in the first 3 yr of Expt 1, determined by bioassay, depended on the depth of added inoculum and amount of disease in subsequent crops. However, at the time of the naturally occurring peak of disease severity (in either inoculated or non‐inoculated plots) it did not predict either disease or TAD.

Differences and similarities amongst epidemics developing naturally and those developing from different amounts and placement of applied inoculum have been revealed. The epidemiological implications of adding inoculum and the potential value of artificially‐created epidemics of take‐all in field trials are discussed.
Effects of irradiance on growth and flowering in the shade plant, cineraria
Authors: YEH D M , ATHERTON J G
Published: February 2008

Effects of total irradiance on growth and flowering were studied in cineraria cv. Cindy Blue grown under warm (mean 21°C) glasshouse conditions. Efficiency of light conversion for leaf and shoot dry weight increase were reduced from 0.08 to 0.02 as the mean daily light integral increased from 0.9 to 4.4 MJ m‐2 day‐1 but no significant difference in leaf area were associated with this. Specific leaf area decreased exponentially from 0.07 to 0.02 m2g1 over the cumulative irradiance range 23 to 127 MJ m‐2 after the start of treatments and thereafter remained stable. A light integral of 19.2 MJ m‐2 were required for initiation of one leaf in plants grown under a daily integral of 4.4 MJ m‐2 day‐1, as compared with only 5.1 MJ m‐2day‐1 required per leaf in plants grown at less than 0.9 MJ m‐2day‐1. Neither chronological duration of juvenile development nor leaf number below the flower was affected by irradiance. However, as the rate of leaf initiation increased with irradiance up to 2.4 MJ m‐2day‐1 so the rate of progress to flower visibility increased linearly with irradiance over the same range. This rate then remained constant from 2.4 to 4.4 MJ m‐2day‐1. Length of the main flowering shoot decreased and the number of flowering shoots increased as irradiance increased from 0.9 to 2.4 MJ m‐2 day‐1 and then remained unchanged by further increases in irradiance.
Properties of Microstructure‐Controllable Porous Yttria‐Stabilized Ziroconia Ceramics Fabricated by Freeze Casting
Authors: Zuo Kai Hui , Zeng Yu‐Ping , Jiang Dongliang
Published: February 2008

Porous yttria‐stabilized ziroconia (YSZ) ceramics were fabricated by freeze casting using aqueous ceramic slurries. Polyvinyl alcohol (PVA) was added to the slurry with the aim of controling the microstructures and properties of the porous YSZ ceramics. The experimental results indicated that the large and noninterconnected lamellar pores of YSZ ceramics without PVA transformed changed into small and interconnected lamellar pores with PVA addition. The porosities of YSZ ceramics with PVA addition were higher than those of YSZ ceramics without PVA addition. The compressive strength of porous YSZ ceramics is the range from 23.57 to 63.86 MPa. All specimens exhibit noncatastrophic failure behaviors.
Microstructure and Creep Behavior of Silicon Nitride and SiAlONs
Authors: Fox Kevin M. , Hellmann John R.
Published: February 2008

Microstructural evolution of silicon nitride (Si3N4) and SiAlON materials and its influence on creep resistance is reviewed. Grain size, grain morphology, and the ratio of α‐ to β‐phase grains play a part in resistance to creep. The glassy, intergranular phase typically has the strongest influence on creep. Creep data are usually obtained using uniaxial tensile or compressive tests, where creep in tension is controlled by cavitation and grain boundary sliding controls creep in compression. The impression creep methodology is also reviewed. An additional creep mechanism, dilation of the SiAlON grain structure, was found to be active in impression creep.
Influence of TiO2 Solid Solution on the Thermal Property and Ionic Conductivity Of Partially Stabilized Zirconia
Authors: Miyazaki Hidetoshi
Published: February 2008

TiO2(0–20 mol%)‐3 mol% yttria‐stabilized zirconia (3YSZ) ceramics were prepared by a solid‐state reaction. With increasing TiO2 content in 3YSZ, the structure of the main phase changed from a monoclinic, tetragonal, and cubic mixture to a tetragonal single phase. Increasing TiO2 content in 3YSZ caused an increase in the average grain size of these ceramics. The thermal conductivity decreased from 4.1 to 2.1 at room temperature with an increase in the TiO2 content. The specific heat of non‐TiO2‐doped 3YSZ was slightly larger than all the doped TiO2–3YSZ at room temperature. When the TiO2 content was >8 mol% in 3YSZ, no abrupt expansion, shrinkage, or cracks were observed on heating and cooling these samples; thus, the thermal stability of 3YSZ was improved by TiO2 solid solution. The ionic conductivity of the samples decreased with increasing TiO2 solid solution.
High‐Yield Synthesis of Nanocrystalline Tin Dioxide by Thermal Decomposition for Use in Gas Sensors
Authors: Agashe Chitra , Aiyer Rohini C. , Garaje Anil
Published: February 2008

High‐yield synthesis of nanocrystalline tin dioxide (nano‐SnO2) using a two‐step thermal decomposition process is reported. Stannous chloride with glacial acetic acid was the precursor to form tin diacetate, whose thermal decomposition gave nano‐SnO2. The yield of respective steps matched well with theoretically expected values, by 85% for tin diacetate and by 94% for nano‐SnO2. Material characterization was done using X‐ray diffraction (phase and particle size) and transmission electron microscopy. The nano‐SnO2 particles were successfully used to develop thick film H2 sensors. The sensor characteristics were closely related to the micro‐structural properties of nano‐SnO2.
Globular clusters and dwarf spheroidal galaxies
Authors: Van Den Bergh Sidney
Published: February 2008

Traditionally, globular clusters and dwarf spheroidal galaxies have been distinguished by using one or more of the following criteria: (i) mass, (ii) luminosity, (iii) size, (iv) mass-to-light ratio and (v) spread in metallicity. However, a few recently discovered objects show some overlap between the domains in parameter space that are occupied by galaxies and clusters. In this Letter, it is shown that ellipticity can, in some cases, be used to help distinguish between globular clusters and dwarf spheroidal galaxies.
Four faint T dwarfs from the UKIRT Infrared Deep Sky Survey (UKIDSS) Southern Stripe
Authors: Chiu Kuenley , Liu Michael C. , Jiang Linhua , Allers Katelyn N. , Stark Daniel P. , Bunker Andrew , Fan Xiaohui , Glazebrook Karl , Dupuy Trent J.
Published: February 2008

We present the optical and near-infrared photometry and spectroscopy of four faint T dwarfs newly discovered from the UKIDSS first data release. The sample, drawn from an imaged area of ∼136 deg2 to a depth of Y= 19.9 (5σ, Vega), is located in the Sloan Digital Sky Survey (SDSS) Southern Equatorial Stripe, a region of significant future deep imaging potential. We detail the selection and followup of these objects, three of which are spectroscopically confirmed brown dwarfs ranging from type T2.5 to T7.5, and one is photometrically identified as early T. Their magnitudes range from Y= 19.01 to 19.88 with derived distances from 34 to 98 pc, making these among the coldest and faintest brown dwarfs known. The T7.5 dwarf appears to be single based on 0.05-arcsec images from Keck laser guide star adaptive optics. The sample brings the total number of T dwarfs found or confirmed by UKIDSS data in this region to nine, and we discuss the projected numbers of dwarfs in the future survey data. We estimate that ∼240 early and late T dwarfs are discoverable in the UKIDSS Large Area Survey (LAS) data, falling significantly short of published model projections and suggesting that initial mass functions and/or birth rates may be at the low end of possible models. Thus, deeper optical data have good potential to exploit the UKIDSS survey depth more fully, but may still find the potential Y dwarf sample to be extremely rare.
Neutrinos as galactic dark matter in the Ursa Major galaxy group?
Authors: Gentile G. , Zhao H. S. , Famaey B.
Published: February 2008

We present the analysis of 23 published rotation curves of disc galaxies belonging to the Ursa Major group of galaxies, with kinematics free of irregularities. The rotation curves are analysed in the context of modified Newtonian dynamics (MOND). We add an extra component to the rotation curve fits, in addition to the stellar and gaseous discs: a speculative halo of constant density made of, for example, neutrinos, which would solve the bulk of the problem currently faced by MOND on rich galaxy cluster scales. We find that this additional unseen mass density is poorly constrained (as expected a priori, given that a neutrino halo never dominates the kinematics), but we also find that the best-fitting value is non-zero: ρ= 3.8 × 10−27 g cm−3, and that a zero density is marginally excluded with 87 per cent confidence; also, the 95 per cent confidence upper limit for the density is ρ= 9.6 × 10−27 g cm−3. These limits are slightly above the expectations from the Tremaine–Gunn phase-space constraints on ordinary 2 eV neutrinos, but in accordance with the maximum density expected for one or two species of 5 eV sterile neutrinos.
The role of the disc magnetization on the hysteresis behaviour of X-ray binaries
Authors: Petrucci Pierre-Olivier , Ferreira Jonathan , Henri Gilles , Pelletier Guy
Published: February 2008

We present a framework for understanding the dynamical and spectral properties of X-ray binaries, where the presence of an organized large-scale magnetic field plays a major role. Such a field is threading the whole accretion disc with an amplitude measured by the disc magnetization μ(r, t) =B2z/(μoPtot), where Ptot is the total, gas and radiation, pressure. Below a transition radius rJ, a jet emitting disc (JED) is settled and drives self-collimated non-relativistic jets. Beyond rJ, no jet is produced despite the presence of the magnetic field and a standard accretion disc (SAD) is established. The radial distribution of the disc magnetization μ adjusts itself to any change in the disc accretion rate , thereby modifying the transition radius rJ.

We propose that a SAD-to-JED transition occurs locally, at a given radius, in a SAD when μ=μmax≃ 1 while the reverse transition occurs in a JED only when μ=μmin≃ 0.1. This bimodal behaviour of the accretion disc provides a promising way to explain the hysteresis cycles followed by X-ray binaries during outbursts.
RECOVERY OF SINAPIC ACID FROM A WASTE STREAM IN THE PROCESSING OF YELLOW MUSTARD PROTEIN ISOLATE
Authors: PRAPAKORNWIRIYA N. , DIOSADY L.L.
Published: February 2008

A large amount of waste permeates generated from the processing of yellow mustard protein was concentrated fivefold using a nanofilter with a molecular weight cut off of 1,000 Da, while approximately 74% of sinapic acid was retained. Sinapic acid was then released from sinapine, its esterified form, by an alkaline hydrolysis. The hydrolyzed solution was acidified to prevent oxidation of the sinapic acid and to precipitate the remaining proteins. Subsequently, sinapic acid and other phenolics were extracted by a two‐stage extraction using a mixture of diethyl ether and ethyl acetate (1:1), 165‐min extraction time and permeate‐to‐solvent ratio of 1:2. Approximately 95% of the sinapic acid in the acidified permeate was finally concentrated in the solvent phase.

PRACTICAL APPLICATIONS

This development has led to an economical process to recover phenolics and to treat effluent from a process of oilseed protein while reducing the use of water during the extraction of protein. A reduction of water usage makes the processing of oilseed protein isolate more economically attractive, and the recovered phenolics may find a use as a nutraceutical. The developed process is not only limited to the recovery of phenolics from mustard, but also applied for recovering phenolic acids, specifically sinapic acid, from waste water from membrane processing of protein from mustard and similar polyphenol‐containing oilseeds.
EFFECTS OF AMIDATED LOW METHOXYL PECTIN ON HEALTHY RESTRUCTURED FISH FOOD FROM MEXICAN FLOUNDER (CYCLOPSETTA CHITTENDENI)
Authors: RODRÍGUEZ NUBIA R. , URESTI ROCIO M. , VELAZQUEZ GONZALO , VÁZQUEZ MANUEL , RAMÍREZ JOSÉ A.
Published: February 2008

Nowadays an increasing demand of functional foods exists. In the case of fish products, pectins can be added to offer an additional healthy value to the consumer with a positive effect in the textural properties. Therefore, it is possible to take advantage of species with low commercial value or that are captured incidentally and sacrificed by error, like Mexican flounder (Cyclopsetta chittendeni). The objective of this work was to determine the effect of the addition of amidated low methoxyl pectins (ALMPs) on the functional and mechanical properties of restructured fish products from Mexican flounder. Different concentration of pectins (0 as control, 10, 20, 30 or 50 g/kg) and degrees of amidation (5, 10 or 25%) were studied. The fish pastes obtained were incubated at 40C for 30 min before they were cooked at 90C for 20 min. Backward extrusion, expressible water (Ew) and color of fish pastes were determined, and treated gels were characterized by changes in mechanical properties (texture profile analysis, puncture test and torsion test), Ew and color. Results obtained suggest that the ALMP with the highest degree of amidation increased mechanical properties and the water‐holding capacity of fish gels. Gels containing 10 g/kg of 10 or 25% ALMP showed adequate mechanical and functional properties with almost no changes perceptible in color attributes. ALMP can be used to offer to consumers healthier fish foods based on mexican flounder.

PRACTICAL APPLICATIONS

A new application to Mexican flounder (Cyclopsetta chittendeni), an abundant fish species in the Gulf of Mexico, was found. High volumes of this species are incidentally caught as part of the shrimp bycatch and discarded because of their small size. The results showed that with the use of amidated low methoxyl pectin as additive, a healthier fish food can be obtained.
EFFECT OF ROTATION ON PROCESS TIME OF THERMALLY PROCESSED MACKEREL IN OIL IN ALUMINUM CANS
Authors: ALI A. ANSAR , SUDHIR B. , MALLICK A.K. , GOPAL T.K. SRINIVASA
Published: February 2008

This study was conducted to standardize the optimum processing condition for thermal processing of mackerel in refined groundnut oil in aluminum cans. The standardization of the product was carried out in still retort at 121.1C at three different Fo (accumulated lethality) values, i.e., 5, 7 and 9. The total process times required to reach the Fovalues 5, 7 and 9 were 34.06, 41.29 and 45.09 min, respectively. The Fo9 was selected for further rotation studies based on sensory analysis and sterility test. Rotation was carried out at 2, 4 and 6 rpm and resulted in the reduction in the process time to 42.08, 41.38 and 38.22 min, respectively, for the same lethality compared to 45.09 min in stationary retort. The cook value also reduced with increase in the rotational speed.

PRACTICAL APPLICATIONS

The present work was carried out to standardize the optimum thermal processing parameters for mackerel in oil medium in aluminum cans and to study the effect of rotation on process time. The standardization of process parameters will help the processors to directly implement in commercial retort operation. The longer duration of thermal processing leads to the deterioration of product quality. Reductions in process time will have an advantageous effect on the sensory and nutritional qualities of thermally processed fish products. The reduction of process time can be achieved by rotating the content of canned product during processing. In rotational study, it has been observed that the total process time could be reduced to 6 min compared to the stationary retort sterilization process at a given temperature and Fo value. This will help the processes to minimize the energy consumption for thermal processing and to produce better quality products.
OVERALL HEAT TRANSFER COEFFICIENTS AND AXIAL TEMPERATURE DISTRIBUTION IN A TRIPLE TUBE HEAT EXCHANGER
Authors: BATMAZ EDIZ , SANDEEP K.P.
Published: February 2008

Computation of overall heat transfer coefficients in a triple tube heat exchanger (TTHE) is more complicated than in the case of a double tube heat exchanger (DTHE) as the two overall heat transfer coefficients are not independent of one other. A new procedure was developed to calculate these overall heat transfer coefficients and an effective overall heat transfer coefficient value for known inlet and outlet temperatures, and heat capacities of the fluids (product and heating/cooling medium). In this study, this newly developed procedure was utilized and the overall heat transfer coefficients and axial temperature distribution of fluids were computed for a cooling process for different flow rates and inlet temperatures of the fluid streams. The effectiveness of the TTHE was compared to that of a DTHE of identical length. It was observed that when the fluids were flowing in a cocurrent manner, the temperature of the cooling medium with lower heat capacity exceeded the temperature of the product before the fluids exit the TTHE, which caused a decrease in the effectiveness of the TTHE.
Complications following tarsal arthrodesis using bone plate fixation in dogs
Authors: Roch S. P. , Clements D. N. , Mitchell R. A. S. , Downes C , Gemmill T. J. , Macias C. , McKee W. M.
Published: February 2008

Objectives:To report the complications encountered following tarsal arthrodesis surgery with bone plate fixation and describe the previously unreported complication of plantar necrosis.

Methods:Medical records of 40 dogs that had been treated by tarsal arthrodesis with bone plate fixation were reviewed to determine the major and minor complications and the associated risk factors.

Results:The major complication rate was 32·5 per cent and the minor complication rate was 42·5 per cent. Pantarsal arthrodeses had a higher major complication rate than partial tarsal arthrodeses. Plantar necrosis was the most common major complication and occurred in 15 per cent of cases. Plantar necrosis occurred more frequently when a bone plate was applied to the medial aspect of the hock, and only occurred in cases where tarsometatarsal joint arthrodesis was performed.

ClinicalSignificance:Plantar necrosis is a catastrophic complication that may be associated with injury to the dorsal pedal artery or perforating metatarsal artery. Application of a bone plate to the medial aspect of the hock should be performed with care during tarsal arthrodesis, particularly where the tarsometatarsal joint is debrided of cartilage. Strict attention to surgical technique and proper postoperative coaptation is critical to reduce the potential for complications with tarsal arthrodesis.
Min-Max Load Model for Optimizing Machining Fixture Performance
Authors: De Meter E. C.
Published: February 2008

Spherical-tipped locators and clamps are often used for the restraint of castings during machining. For structurally rigid castings, contact region deformation and micro-slippage are the predominant modes of workpiece displacement. In turn contact region deformation and micro-slippage are heavily influenced by contact region loading. Maximum loading magnitude has been shown to be a good indicator of workpiece displacement. This paper presents an algorithm which uses the min-max loading criteria as a basis for determining the optimal layout of locators and clamps as well as clamp actuation intensities. The experimentation used for model validation is also discussed along with experimental results.
Bearing Localized Defect Detection by Bicoherence Analysis of Vibrations
Authors: Li C. James , Ma J. , Hwang B.
Published: February 2008

For automatic detection and diagnosis of localized defects in rolling element bearings, bicoherence spectra are used to derive features that signify the condition of a bearing. These features quantitatively describe the degree of phase correlation among any three harmonics of bearing characteristic defect frequencies. In this paper, theory of bicoherence is explored to establish its utilization in the detection of bearing localized defects. Experimental results show that the proposed method is effective in bearing defect detection and sensitive to incipient defects.
A Fuzzy Self-Learning Control Method with Application to Hydroforming Processes
Authors: Park H. J. , Cho H. S.
Published: February 2008

In this paper, a tracking control of hydroforming pressure which is used for precision forming of sheet metals, is considered. In this process, forming pressure of the process needs to be strictly controlled to ensure high quality of the forming products. However, conventional control method alone makes it difficult to achieve satisfactory control performance due to complexities and uncertainties of the process. To overcome this problem, a fuzzy self-learning control scheme is proposed. In the proposed scheme, a series of experiments were performed to show the effectiveness of the proposed control scheme and to investigate influence of the design parameters of the proposed algorithm. The experimental results show that the proposed fuzzy self-learning controller can guarantee good tracking performance and thus, high quality of products even when knowledge of the process is vague, imprecise and fragmentary.
An Experimental Investigation of Damage Evolution in a Ceramic Matrix Composite
Authors: Walter M. E. , Ravichandran G.
Published: February 2008

The mechanical behavior of a glass-ceramic matrix composite, SiC/CAS (calcium aluminosilicate reinforced with unidirectional SiC fibers), is studied. Results based on uniaxial tension experiments are presented for specimens with fibers aligned in the loading direction. Axial and transverse strain gages on all four gage section surfaces and in situ acoustic emission and ultrasonic wave speed measurements were used to monitor the evolution of damage. All measurements were made with high-resolution, continuous data acquisition. Post-test optical and scanning electron microscopy was also used to identify the various micromechanisms of damage. The experimental results demonstrate the existence of “zones of deformation” which are associated with the onset of different damage mechanisms. It is shown that the observed stress-strain behavior can be explained in terms of the material properties of the matrix and the fiber, the material processing, and the postulated zones of deformation.
Thermomechanical Fatigue Behavior of a Quasi-lsotropic SCS-6/Ti-15-3 Metal Matrix Composite
Authors: Hart K. A. , Mall S.
Published: February 2008

The response of a quasi-isotropic laminate of metal matrix composite, SCS-6/Ti-15-3 in a thermomechanical fatigue (TMF) environment was investigated. To achieve this, three sets of fatigue tests were conducted: 1) in-phase TMF (IP-TMF), 2) out-of-phase TMF (OP-TMF), and 3) isothermal fatigue (IF). The fatigue response was dependent on the test condition and the maximum stress level during cycling. The IF, IP-TMF, and OP-TMF conditions yielded shortest fatigue life at higher, intermediate and lower stress levels, respectively. Examination of the failure mode through the variation of strain or modulus during cycling, and post-mortem microscopic evaluation revealed that it was dependent on the fatigue condition and applied stress level. Higher stresses, mostly with IP-TMF and IF conditions, produced a primarily fiber dominated failure. Lower stresses, mostly with the OP-TMF condition, produced a matrix dominated failure. Also, an empirical model based on the observed damage mechanisms was developed to represent the fatigue lives for the three conditions examined here.
Crack Growth Rate Behavior of a Titanium-Aluminide Alloy During Isothermal and Nonisothermal Conditions
Authors: Pernot J. J. , Mall S. , Nicholas T.
Published: February 2008

Observations of isothermal fatigue, isothermal fatigue with superimposed load hold times, and thermomechanical fatigue (TMF) crack growth rate behavior of Ti-24Al-11Nb are presented and compared with results from previous studies on titanium and nickel-base superalloys. Elevated-temperature crack growth mechanisms in this alloy, which involve fatigue, oxidation and creep, and the influence of frequency, temperature, and hold-time are discussed. These mechanisms are used to interpret the observations of TMF crack growth. The limitations of current crack growth rate models based on the linear-elastic fracture mechanics parameter, K, are addressed.
The Importance of Material Structure in the Laser Cutting of Glass Fiber Reinforced Plastic Composites
Authors: Caprino G. , Tagliaferri V. , Covelli L.
Published: February 2008

A previously proposed micromechanical formula, aiming to predict the vaporization energy Qv of composite materials as a function of fiber and matrix properties and fiber volume ratio, was assessed. The experimental data, obtained on glass fiber reinforced plastic panels with different fiber contents cut by a medium power CO2 cw laser, were treated according to a procedure previously suggested, in order to evaluate Qv. An excellent agreement was found between experimental and theoretical Qv values. Theory was then used to predict the response to laser cutting of a composite material with a fiber content varying along the thickness. The theoretical predictions indicated that, in this case, the interpretation of the experimental results may be misleading, bringing to errors in the evaluation of the material thermal properties, or in the prediction of the kerf depth. Some experimental data were obtained, confirming the theoretical findings.
Constitutive Equations for Commercial-Purity Aluminum Deformed Under Hot-Working Conditions
Authors: Puchi E. S.
Published: February 2008

A rational analysis of a number of stress-strain curves for a commercial-purity aluminum has been carried out in order to derive a set of constitutive equations capable of describing the flow stress of the material in terms of the applied strain, rate of straining, and deformation temperature. Such an analysis combines the exponential saturation strain-hardening function earlier proposed by Voce (1948; 1955) with the exponential relationship developed from steady-state creep data at high stresses, and considers the existence of two different regimes of work-hardening. The proposed formalism requires only the use of seven material constants which include the temperature-dependent shear modulus, the activation energy for self-diffusion, one pre-exponential factor, and four stress sensitivity parameters of the strain rate. A satisfactory correlation has been obtained between the experimental values of the flow stress and those predicted for the model, which enables it to be used in conjunction with any algorithm based on finite differences methods or finite elements codes to simulate hot-working operations carried out in this material.
A Constitutive Model for Estimating Multiaxial Notch Strains
Authors: Lee Yung-Li , Chiang Yung J. , Wong Hang-Hong
Published: February 2008

True stress and strain components at a notch are the essential parameters for fatigue life predictions. Nonlinear finite element analysis (FEA) could be the perfect solution to the notch stress and strain calculation, but its usage may be very limited due to intensive CPU time consumption. Estimation techniques for the multiaxial notch stresses and strains from linear FEA results are important and needed. The existing approach—the Hoffmann and Seeger theory—is limited for monotonic loading cases. It appears difficult to extend its application to nonproportional and variable amplitude loading cases. A generalized method for estimating multiaxial notch stresses and strains on the basis of elastic stress solutions is presented here. This method utilizes a two-surface model with the Mroz hardening equation and the associated flow rule to simulate the local notch stress and strain responses for any geometrical constraints of specimens under monotonic, in-phase and out-of-phase loading. The uniaxial material properties associated with the two-surface model are determined by: the Neuber rule, the Glinka rule and FEA results. Comparisons are made with the notch strains calculated by nonlinear FEA and those obtained from strain gages. Reasonable correlations between the measured and predicted notch strains are observed for SAE 1045 material.
Fatigue Damage Calculation Using the Critical Plane Approach
Authors: Chu C.-C.
Published: February 2008

The critical plane approach is applied to model material fatigue behavior under any constant amplitude proportional loading. The most critical plane and the largest damage parameter are determined in closed form for six damage criteria that have been proposed in the literature. The correct procedures of utilizing these closed-form solutions to construct the damage parameter versus fatigue life curve are outlined. It is shown that the common practice of characterizing the material’s fatigue behavior by plotting the damage parameter evaluated on the maximum shear plane against the observed fatigue life violates the principle of the critical plane approach, a problem which can arise during the calibration of any biaxial type of damage criterion. The study emphasizes that the critical plane approach should be consistently applied to both the initial calibration and the subsequent fatigue analysis.
The Role of Gas Dissolution and Induced Crystallization During Microcellular Polymer Processing: A Study of Poly (Ethylene Terephthalate) and Carbon Dioxide Systems
Authors: Baldwin Daniel F. , Shimbo Minuro , Suh Nam P.
Published: February 2008

One of the critical steps in the production of microcellular polymers is the dissolution of gas into a polymer matrix. In this paper, the formation of a gas and semi-crystalline thermoplastic solution is studied in the presence of a crystallizing matrix with particular emphasis on the ultimate effects of crystallinity on microcellular polymer processing. In this particular study, carbon dioxide was selected as the gas and poly (ethylene terephthalate) (PET) as the polymer. Polymer/gas solution formation is the precursor to the microvoid nucleation and growth during microcellular polymer processing. In batch processing, the solution formation is typically accomplished by placing a polymer sample in a high pressure gas environment resulting in the diffusion of gas into the polymer matrix. For gas and semi-crystalline thermoplastic systems, the solution formation process is notably more complex. In particular, PET crystallizes in the presence of high Co2 solution concentrations. The crystallization results in a solution that is relatively difficult to microcellular process, requiring relatively high temperatures as compared to amorphous polymer/gas solutions. However, the resulting crystalline foam has a superior microcellular morphology. In addition, the crystallization of the solution results in a lower solubility, an increased matrix stiffness, and a lower diffusivity. Our analysis includes (1) an experimental characterization of the carbon dioxide-induced crystallization occurring during microcellular polymer processing, indicating a critical gas concentration is required for crystallization, (2) an experimental estimation of the vis-coelastic behavior of amorphous and semi-crystalline PET/CO2 solutions, and (3) an experimental investigation of the effects of crystallinity on microcellular processing and the resulting cell morphology. Crystallinity was found to play a major role in microcellular processing through its effects on (a) cell nucleation mechanisms resulting in larger cell densities due to heterogeneous nucleation at the amorphous/crystalline boundaries and (b) cell growth mechanisms resulting in smaller cell sizes due to the increased matrix stiffness of the semi-crystalline matrix.
An Experimental Investigation of Resin Flow Sensing During Molding Processes
Authors: Kikuchi Akihisa , Higuerey Evelitsa , Coulter John
Published: February 2008

The present investigation focused on the need for sensing subsystems for the monitoring of resin flow dynamics during molding processes. Such subsystems, when combined with process parameter control, will produce intelligent manufacturing systems that could significantly improve manufacturing capabilities. A concise review of potential resin flow monitoring methodologies is included, and a detailed analysis of one particular sensing concept originally investigated at the U. S. Army Materials Technology Laboratory is presented. The concept is based on embedded electronic sensors, and during the present study a resin front monitoring system based on a modified version of this concept was developed. Electrically conductive wires were embedded orthogonally in a nonintersecting manner within mold cavities. Subsequent resin flow was sensed by monitoring the electrical characteristics of circuits which resulted during processing. A novel modification of circuitry was included to allow for the monitoring at multiple locations with a single electronic circuit. The net result of this modification was an improved response time of the overall sensing subsystem. The concept was verified experimentally through the performance of both one-dimensional (TD) and two-dimensional (2-D) experiments. The resin system utilized consisted of a mixture of epoxy resin (EPON 826) and a curing agent (MHHPA). The sensed flow front progression information was validated through controlled injection rate experimentation and flow visualization results obtained with transparent molds. It was concluded that the resin flow sensing subsystem could be applied to relatively slow molding processes. Positive and negative aspects related to the applicability of the sensing method to actual manufacturing processes are discussed.