Search

Nanoscale and submicron powder of zinc oxide (ZnO) is known as a highly efficient photocatalyst that is promising for solving the problem of wastewater treatment from toxic organic pollutants including phenol and its derivatives. The results of laboratory studies of ZnO preparation by a simple, energy-saving, and highly productive method of solution–combustion synthesis from a mixture of solutions of zinc nitrate and glycine, as well as the use of the ZnO powder synthesized by combustion for the photocatalytic decomposition of phenol, are presented. The modes and characteristics of combustion, phase composition, chemical composition, and structure of the combustion product at different ratios of glycine with zinc nitrate were determined. It is shown that calcination at 650 °C reduces the content of carbon impurity in the combustion product to ~1 wt.% and leads to obtaining ZnO powder in the form of porous agglomerates up to 100 μm in size sintered from crystalline nanoscale and submicron ZnO particles with an average crystallite size of 44 nm. The ZnO powder exhibits high photocatalytic activity, leading to the almost complete degradation of phenol in an aqueous solution under the action of ultraviolet irradiation in less than 4 h.

The effect of heat treatment on the mechanical properties (hardness, plasticity, yield and tensile strength) and corrosion resistance of several cast magnesium alloys with additions of rare earth metals (Y, Nd and Gd), and their surface modification by plasma electrolytic oxidation (PEO) were investigated. It was found that the heat treatment of the alloys results information of Mg12YZn, Mg3Zn3Y2 and Mg24Y5 based LPSO-phases and causes an increase in hardness and tensile strength by 5-7 and 20-25%, respectively, but at the same time, corrosion resistance of the alloysdrops by 10-20 times. PEO of the alloys after heat treatment reduced the corrosion currents by 1-3 orders of magnitude without changing the corrosion potential.

Results from experiments on the annealing of icosahedral small particles (ISPs) of copper in different gas media are presented. The growth of nanowhisker structures and nanopores on the surfaces of ISPs is observed. The multilayer internal structure of annealed ISPs that incorporate a metallic core, cavities, and copper oxide layers is revealed.

Aiming at better understanding of the deformation mechanisms involved into plastic deformation of duplex stainless steels, acoustic emission (AE) measurements were performed during room temperature tensile deformation of model steels and alloys with different phase structure including single phase i Fe­30Cr and £ SUS316L steels and duplex i­£ SUS329J4L, Fe­24Cr­6Ni alloys. The real time AE investigations were complemented by microscopic investigations of deformed microstructures. The quantitative AE analysis revealed different AE patterns which were correlated with underlying deformation mechanisms and microstructural transformations. The cluster analysis of AE power spectral densities has been proven effective in revealing specific groups of signals (clusters) which appear on different deformation stages in different steel variants, which can be correlated with involved source mechanisms of plastic deformation and microstructural processes including dislocation slip in either fcc or bcc lattice of £ or i phase, respectively, twinning in the SUS 316L steel and £­iA martensitic transformation in the Fe­24Cr­6Ni model alloy. [doi:10.2320/matertrans.MBW201203]

The concentration of hydrogen with different binding energies and acoustic emission initiated by indentation in VT1-0 commercial titanium in the initial state and after barocryodeformation are measured. The acoustic parameters are found to correlate with the hydrogen concentration in the material.

Hydrogen with different bond energies and indentation-induced acoustic emission in the initial (homogenized) state of Kh18N10T stainless steel and after barocryodeformation by 18 and 31% are studied. A correlation between the acoustic parameters and the hydrogen content in the material is found.

Resume L’hemorragie aigue demeure une des premieres causes de mortalite en traumatologie et ce malgre les progres de la chirurgie et de la radiologie interventionnelle. La strategie transfusionnelle est une des cles de la reanimation du choc hemorragique. Des donnees recentes sur la physiopathologie des troubles de l’hemostase au cours du choc hemorragique et sur la physiologie de l’hemostase permettent aujourd’hui de preconiser un recours plus precoce a la transfusion sanguine dans ce cadre.

We report the case of an acute respiratory failure in a 36-year-old woman who presented a peripartum cardiomyopathy (PPCM). PPCM is a dilated cardiomyopathy with impaired systolic function that occurs between the last month of pregnancy and the five months following delivery. It is a rare disorder of unknown origin associated with high mortality (50%). Echocardiography confirms the diagnosis by showing a left ventricular dilatation and a decreased ejection fraction. Up to date, the treatment remains symptomatic.

Processing of fruits and vegetables in 603 × 700 cans for institutional use is a common commercial practice. The present time-temperature treatments for assuring commercial sterility are often excessive and unavoidably detrimental to product quality. Using the count reduction system of process lethality evaluation, canned whole peeled tomatoes packed in juice and fruits packed in syrup were experimentally flame sterilized as rapidly in 603 × 700 cans as in 303 × 406 cans.

Increases in ultrafiltration rates were obtained by treating whey with acid, calcium-sequestering agents, or compounds to modify specific protein side chains, or by increasing the ionic strength. The proteins in whey, examined by scanning electron microscopy, underwent marked structural changes corresponding to these changes in the chemical environment. Depending upon the treatment, membrane fouling deposits showed strands, lattice networks, beaded matrixes, helical structures, or protein sheets of varying thickness. The protein forms were affected by the pH, the quantity of reagent added, and the protein functional group which was modified. Fouling of membranes was reduced when formation of protein sheets over the membrane was retarded.

Summary Scanning electron microscopy (SEM) was used to study the fouling deposits from cottage cheese whey on ultrafiltration membranes. Several types of deposits were observed: micro-organisms, granules, thin strands, coarse fibres and sheets of varying thickness. Surface deposits of sheet forming materials appear to be the principal cause of membrane flux decline. The progressive build-up of deposits was demonstrated directly on ultrafiltration membranes and by simulation of fouling on membranes having uniform pores discernible by SEM. SEM was found to be a simple and effective tool for study of membrane fouling.

Signals of acoustic emission (AE) arising in the process of uniaxial stretching of specimens of pipe steels of various grades heat treated under conditions of commercial production are studied. The AE signals are classified into groups according to the shape of the spectral density curve. A classification including four basic groups of signals and their modifications is suggested.

Spontaneous rupture of the spleen is a rare complication of chronic calcifying pancreatitis. Anaemia and haemorrhagic shock may occur but pain is the first symptom making diagnosis more difficult. We report the case of a 32-year-old man suffering from chronic pancreatic pathology who developed a spontaneous splenic rupture. He complained of abdominal pain without haemorrhagic shock. An abdominal CT-scan revealed a rupture of the spleen with a haemoperitoneum.

A semi-analytical (concerning the particle temperature) semi-numerical (concerning the fluid temperature) solution to the differential equations governing heat transfer to axially rotating liquid/particulate canned foods was obtained using Duhamel's theorem and a numerical 4th-order Runge-Kutta scheme. This solution avoids some of the shortcomings of earlier solutions such as the requirement for constant heating medium temperature, the need for empirical formulas, or the use of unrealistic assumptions regarding the fluid temperature. the agreement between the proposed solution and limiting case analytical results was very good. A maximum fluid temperature difference of less than 2C was momentarily observed at the beginning of heating; differences between particle surface temperatures were even smaller. Comparison between predicted values and experimental data from the literature showed good agreement only as far as the fluid temperature was concerned; particle surface temperatures deviated significantly.

Particle surface temperatures were measured by liquid crystals that allowed unrestricted motion of the monitored particles. Liquid-particle film heat transfer coefficients (hp) were considerably higher than published values which were determined with particles attached to thermocouple wires. In general, as a result of the particle motion, hp increased with increasing rotational speed and increasing fluid viscosity. Furthermore, hp values were higher for Teflon spheres than for aluminum spheres. Results for the overall (heating medium/container wall/internal liquid) heat transfer coefficients were consistent with published observations.

A new method, involving the use of liquid crystals as temperature sensors, was developed to measure surface temperatures on moving particles. The method involves coating the monitored particles with aqueous solutions of encapsulated liquid crystals and recording the color changes on the particle surface as a function of temperature. Experimentally measured particle surface and liquid temperatures were used to calculate heat transfer coefficients for water-heated, axially rotating, cylindrical acrylic vessels containing liquid and solid spherical particles. The theoretical analysis associated with calculating the heat transfer coefficients from the experimental data is presented. The method is illustrated by measuring overall (heating medium/container wall/internal liquid) and liquid-particle film heat transfer coefficients for Teflon spheres in deion-ized water and aluminum spheres in 1.5 cSt silicone fluid.

A mathematical procedure was developed to estimate heat transfer coefficients for heated rotating cans of food comprised of a liquid and spherical particles. The method uses experimental data for only the fluid temperature, and heat transfer coefficients are obtained by comparing predicted with experimental fluid temperature data in the Laplace transform plane. Results obtained using the procedure were compared with experimentally obtained heat transfer coefficients from the literature for three cases: potato spheres in deionized water, Teflon spheres in deionized water, and aluminum spheres in silicone fluid. Agreement between predicted and experimental results depended upon the agreement of the experimental conditions and the assumptions associated with the model.

High temperature thermal death parameters for Bacillus stearothermophilus TH24 (NCDO 1096) spores in water were determined using a computer-controlled reactor. The equipment produced and recorded accurate, reproducible square-wave temperature transients during very short heating times (−0.1 sec). Survivor curves and the phantom thermal death time (TDT) curve between 130°C and 155°C from reactor data were compared to results from oilbath-heated capillary tubes between 115°C and 135°C. The TDT curve was nonlinear in the high temperature range but could be described by two lines with z = 9.3C° for temperatures between 115°C and 145°C and z = 16.9C° for temperatures above 145°C. An Arrhenius plot did not represent the data better.

Since the last decade, hemofiltration and especially high volume hemofiltration has rapidly evolved from a somewhat experimental treatment towards a potentially effective “adjunctive” therapy in severe septic shock and especially refractory or catecholamine resistant hypodynamic septic shock. Nevertheless, this approach lacks prospective randomized studies (PRT'S) evaluating the critical role of early hemofiltration in sepsis. An important step forward which could be called the “big bang” in term of hemofiltration was the publication of a PRT in patients with acute renal failure (ARF) (1). Before this study (2), nobody believed that hemofiltration could change the survival rate in intensive care. Since that big bang, many physicians consider that hemofiltration at a certain dose can change the survival rate in intensive care. So the world of hemofiltration in ICU is not a definitive world, it is still in expansion. Indeed, we now have to try to define what will be the exact dose we need in septic acute renal failure. This dose might well be “higher” than 35 ml/kg/hour in the septic acute renal failure “group” as suggested by many studies (2–5). At present, it is the issue of continuous dose of high volume hemofiltration that has to be tested in future randomized studies. Since the Vicenza study (2) has shown that 35 ml/kg/h is the best dose in terms of survival, dealing with non septic acute renal failure in ICU, several studies from different groups have shown that, in septic acute renal failure, a higher dose might correlate with better survival. This has also been shown in some way by the study of the “Vicenza group” but not with a statistically significant value (2). New PRT'S have just started in Europe like the IVOIRE study (hIgh VOlume in Intensive caRE) (6) and the RENAL study. Another large study is looking more basically at dose in non septic acute renal failure in Australasia and is led by the group of Rinaldo Bellomo in Melbourne (7) as well as the ATN study (8) led by Palevsky and colleagues in the USA, also testing the importance of dose in the treatment for ARF. Nevertheless, “early goal-directed hemofiltration therapy” like early goal directed therapy (9) has to be studied in our critical ill patients. Regarding this issue, fewer studies, mainly retrospective exist, but again the IVOIRE study (6) will address this issue by studying septic patients with acute renal injury according to the Rifle classification (10). So, this review focuses on the early application and on the adequate dose of continuous high volume hemofiltration in septic shock in order to improve not only hemodynamics, but survival in this very severely ill cohort of patients. This could well be called the “big bang of hemofiltration” as one could never have anticipated that an adequate dose of hemofiltration could markedly influence the survival rate of ICU-septic acute renal failure patients. On top of the use of early and adequate dose of hemofiltration in sepsis, a higher dose could also provide better renal recovery rate and reduce the risk of associate chronic dialysis in these patients. Furthermore, this paper also reviews “brand” new theories regarding the rationale for hemofiltration in sepsis. Finally, this paper also addresses the so-called negative studies as well anticipated side effects.

Haemoglobin E beta thalassaemia is the commonest form of severe thalassaemia in many Asian countries, but little is known about its natural history, the reasons for clinical diversity, or its management. We studied 109 Sri Lankan patients with the disorder over 5 years. 25 patients were not receiving transfusion; transfusion was stopped with no deleterious effect in a further 37. We identified several genetic and environmental factors that might contribute to the phenotypic diversity of the disorder, including modifiers of haemoglobin F production, malaria, and age-related changes in adaptive function. Our findings suggest that haemoglobin E beta thalassaemia can be managed without transfusion in many patients, even with low haemoglobin levels. Age-related changes in the pattern of adaptation to anaemia suggest that different and more cost-effective approaches to management should be explored.

The tylosin-biosynthetic (tyl) gene cluster occupies about 1% of the genome of Streptomycesfradiae and includes at least 43 open reading frames. In addition to structural genes required for tylosin production, the tyl cluster contains three resistance determinants and several regulatory genes. Tylosin production is evidently controlled by pathway-specific and pleiotropic regulators with the likely involvement of y-butyrolactone signalling factors. Accumulation of the polyketide aglycone is controlled by glycosylated macrolides and optimal performance of the complex polyketide synthase enzyme requires the activity of an editing thioesterase.

A numerical analysis was performed to evaluate the convective heat transfer coefficients at the particle-liquid interface as a time-dependent function of system properties for liquid foods containing particulates. The transient energy equations for the sphere and fluid were solved by an alternating-direction implicit method to find the temperature distribution near the particle surface for near zero relative velocity, Re = 0.1. The instantaneous convective heat transfer coefficients varied over the sphere surface and heat flow reversal was observed near the rear stagnation region, which caused the displacement of the coldest point from the center to the particle surface. Lethality computations showed that the critical point was shifted from the particle center toward the rear stagnation point.

Spherical gellan gum gel particles in an aqueous medium were heated in a clear acrylic can under axial rotation. Thermochromic liquid crystals (TLCs) dispersed in a few gel particles provided a means for remotely monitoring temperature changes in the particles. Because of matching refractive indices, the particles without incorporated TLCs became virtually invisible in the aqueous medium and allowed uninterrupted observation of the TLC-containing particles. The ranges of temperatures converted from colors of digitized images of the particles as well as the duration of the colors in the particle were in fair agreement with the limits of mathematically predicted time-temperature curves.

PARMILA (Phase And Radial Motion in Ion Linear Accelerators) is a drift‐tube linac (DTL) ion‐beam dynamics code. Over its long life, many versions have developed. The Los Alamos Accelerator Code Group distributes a version, for which a manual is available. Unless otherwise specified, all mentions of PARMILA in this document refer to that LAACG‐distributed version. Until recently, this documented and distributed version functioned only under CTSS. Users who wished to run on a different operating system needed to convert the code themselves. PARMILA now operates under UNICOS, a much more widely available CRAY operating system, and under VAX/VMS. This paper describes some new features of the code, and gives directions for obtaining the manual and the UNICOS and VMS versions of the code.

Mechanical deaeration in a vacuum closing machine and flame deaeration achieved comparable results in removing noncondensible gases from low-liquid packs of canned green beans and apple slices. Residual headspace oxygen was calculated from experimental measurements of pressure, void volume, and percent oxygen. Prolonged (> 5 set) exposure of hot filled samples to mechanical vacuum prior to seaming did not result in lower residual oxygen. Sample changes through 9 mo storage were not influenced by deaeration method; consequently, residual oxygen or vacuum in cooled samples immediately after sampling may be used to assess adequacy of air removal.

In mechanical deaeration of sliced apples, pears and cut green beans, increasing fill temperatures or chamber vacuum enhanced product deaeration, whereas increasing dwell time under vacuum from 3 to 9 sec did not (p < 0.05). Product ability to resist explosion when subject to sudden vacuum varied with products, firmness and temperature. Control of fill temperature was necessary for proper removal of oxygen from the canned products.

Overall heat transfer coefficients to water and silicone fluids in cans rotating in a steam retort were correlated by (Eq. A): ((A)) where the Reynolds number, pND2/μ, based on the rotational speed of the can, was varied over the range 12 < Re

Four silicone oils with viscosities ranging from 0.0013 Pa-s to 0.3385 Pa-s were used as model liquid foods to measure the heating rates in a specially-designed single-can flame sterilizer. A previously-developed mathematical heat transfer model was experimentally tested with respect to the effect of liquid viscosity, can rotation, combustion gases crossflow velocity, and can-burner separation. For all the cases studied, order of magnitude agreement was obtained between experimentally measured and predicted heating rates, with experimental values ranging from 0.16°C/s to 0.52°C/s.

This work is a theoretical and experimental analysis of heat transfer to a free falling film of homogeneous fluid food. Fluid falls vertically in a thin film through a stagnant steam environment. the thermal energy equation governing the steady state heat transfer is solved numerically by a finite element method. the Froude number and the Peclet number characterize the fluid flow and heat transfer. Water was used as the experimental test fluid in the steam infusion unit. Average fluid temperatures measured as a function of position compare well with model predictions. the model was incorporation into a kinetic model to predict the extent of microbial destruction expected with the time/temperature treatment.

Methods of detecting the activities of endogenous tomato pectin esterase and polygalacturonase were developed and used to measure heat resistance parameters for enzymes in tomato homogenates. Addition of 0.44% gluconic acid reduced heat resistance of pectin esterase which is responsible for gel formation in canned whole peeled tomatoes. However, heat inactivation of tomato polygalacturonase, which is responsible for general degradation of texture/consistency in tomato products, was not significantly affected by addition of up to 1.65% by wt gluconic acid. Pectic enzymes in canned whole peeled tomatoes packed in juice in 303 × 406 cans were inactivated in 35 min at 98.9 and 101.7°C, 26 min at 110.0°C or 25 min at 118.3°C.

To improve membrane performance and extend the interval between cleanings, a two-step ultrafiltration process is proposed consisting of prefiltration with an open-pored membrane followed by normal ultrafiltration. Three to fourfold increases in permeation rate were observed in laboratory-scale experiments when whey was prefiltered through ultrafiltration membranes of graded porosity to remove microorganisms and protein complexes. It is postulated that fouling occurs when the larger whey constituents settle on the membrane in a lattice network which fills in and is coated over with smaller, sheet-forming whey proteins such as β-lactoglobulin. Fouling substances were studied with scanning electron microscopy and identified by sodium dodecyl sulfate gel electrophoresis.

Clingstone peach and Bartlett pear slices were successfully sterilized by high vacuum flame processes without the conventional covering of syrup or water. The processes developed are simple and continuous, and applicable to commercial use. With the exception of blanching and deaeration, the processes use existing canning practices. Through 18 months storage, more of the original flavor and texture of the fresh fruit was retained by HVFS packs than by the comparable conventional packs. No spoilage was experienced in any of the packs.

Cottage cheese whey solutions containing sodium dodecyl sulfate were resolved electrophoretically on 5% sodium dodecyl sulfate polyacrylamide gels. Major bands were identified by comparing their electrophoretic mobilities to those of known whey components. Other components were identified principally from molecular weights determined from a calibration correlating mobility and molecular weight. Conditions which affect polymerization of proteins were studied in whey and solutions of purified beta-lactoglobulin. Formation of a number of polymers was induced by concentrating the whey samples, lowering the temperature, adjusting pH, or adding salts. The dimer, trimer, tetramer, and octamer of beta-lactoglobulin, the dimer and trimer of bovine serum albumin, and several unidentified components in the 100,000 to 300,000 molecular weight range were observed. The octamer state of beta-lactoglobulin was observed in whey at pH values between 5.1 and 8.0, at temperatures below 10 C, and with .2M addition of potassium thiocyanate, potassium iodide, calcium chloride, or sodium acetate. Similar polymer formation, and temperature and pH effects, were observed with solutions of purified beta-lactoglobulin, which contained dimers, trimers, and tetramers. The beta-lactoglobulin octamer in whey samples could be dissociated by the addition of acid. The bovine serum albumin dimer appeared in whey at pH above 6.2 and at -minus 1 C.

Slices of four major commercial clingstone peach varieties, slices of Bartlett pears from major growing areas, and mixtures of diced peaches and pears were successfully vacuum packed without the conventional covering syrup or water. For selected packs, the fruits were sweetened to the desired cutout ∘Brix value with concentrated syrup. The high vacuum flame sterilized packs (HVFS) required only 7.5 min total heating for pear and peach slices and 5.5 min for diced fruit to achieve biological stability. Because of the minimal process, all HVFS fruits retained more of the original flavor attributes and texture of the fresh fruit through 18 months storage than did the conventional packs. Omission of the covering liquid, combined with the necessary blanching treatment, allowed packing of 1/3 more fruit into a standard size can.

Heat transfer rates were measured for steam-heated, rotating cans containing potato spheres in water. Can rotational speed (9.3–101 rpm), sphere size (22.2–35.0 mm), and potato volume fraction (0.107–0.506) were varied in 14 triplicated experiments. Overall heat transfer coefficients were correlated within ±25% with physical properties and operating variables by an equation derived by dimensional analysis. Film coefficients (hp) for heat transfer from the water to potatoes in the can were determined by thermocouple measurement of potato surface temperatures; values were found to be finite and nearly invariant, averaging hp= 160 ± 30 W/m2K. The lack of variation of hp suggested that for the experimental conditions tested, there was little relative motion between liquid and particles.

Deposits formed on the membrane during ultrafiltration of aqueous solutions of individual whey proteins were examined under a scanning electron microscope. Gamma-globulin formed granules which agglomerated and stacked into layers to form a porous matrix on the membrane. Beta-lactoglobulin and bovine serum albumin both formed sheets on the membrane and formed multimers which were identified by sodium dodecyl sulfate gel electrophoresis. Beta-lactoglobulin also formed strands where deposits were not thick. Alpha-lactalbumin formed smooth spherical particles which did not hinder water permeation greatly. Studies of ultrafiltration rate indicated that beta-lactoglobulin and gamma-globulin were most significant in causing permeation flux decline by surface fouling.

Heat transfer studies were performed with clay suspensions and sugar solutions in 303 × 406 cans heated singly in a flame process simulator. Experimental results show that the can wall temperature does not reach excessive temperatures and that the temperature distribution throughout the can is uniform. The slowest heating point was on the axis near the end of the can but this temperature lagged the center temperature by less than 3°C even with adverse heating conditions (i.e., no head space). The liquid-side heat transfer coefficient in 60% sucrose solution at 30 rpm was measured to be 466 ± 34 W/m2K based on the cylindrical area of the can. Rotational speed had only a small effect on heating rate in the range of 10 to 120 rpm.