Effluent content from albedo degradation and kinetics at different temperatures in the enzymatic peeling of grapefruits

This work studies the variation in the effluent content from the reactor in enzymatic peeling of grapefruits, to determine the loss of soluble solids, reducing sugars and galacturonic acid, the main component from the albedo of the skin to model the solid–liquid transfer in this process. Experiments to study the efficiency of the enzymatic reaction include the effect of the temperature on the kinetics of albedo degradation to find an equation relating both variables and also the activation energy of this process, its value being 36.9 kJ/mol.     

Electrodeposition of Zn–Ni coatings as Cd replacement for corrosion protection of high strength steel

Electrodeposition of Zn–Ni coatings performed in acidic baths are not suitable for high strength steels due to their high susceptibility to hydrogen embrittlement.In this work, Zn–Ni coatings were deposited on a high strength steel (4340) upon stirring conditions from an alkaline bath. A complete characterisation of the coatings (corrosion, morphology and composition) has been accomplished, correlating the electrodeposition conditions with these features. The best protective properties of the grown coatings were achieved for the alloys with a single phase structure of γ-Ni₅Zn₂₁ and a denser morphology. Additionally, the hydrogen content incorporated is lower than even cadmium-coated 4340 steel which has undergone a postbaking dehydrogenation treatment.     

Effect of Silicon and Graphite Degeneration on High-Temperature Oxidation of Ductile Cast Irons in Open Air

Oxidation of Metals - The use of high silicon ductile irons is increasing as they offer some advantages with respect to conventional pearlitic–ferritic grades such as high elongation at...     

Influence of Mn and Cu addition on the hyperfine parameters of amorphous and nanocrystalline FeCoNbB alloys

The effects of Cu and Mn addition on the hyperfine field of FeCoNbB HITPERM alloys are discussed from Mössbauer spectrometry. Amorphous and nanocrystalline samples at different stages of the nanocrystallization were studied. The effect of Cu addition correlates with the observed refinement of the microstructure. Mn mainly partitions to the matrix, decreasing the average hyperfine field of the amorphous matrix, although some Mn remains in the nanocrystalline grains, presumably, in a concentration below the maximum solubility of Mn in -Fe.     

Carbohydrate type and amount alter intravascular processing and catabolism of plasma lipoproteins in guinea pigs

To test the effects of exchanging dietary complex and simple carbohydrate for fat calories on lipoprotein metabolism, guinea pigs were fed two different fat/carbohydrate ratios: 2.5∶58% (w/w) or 25∶29% (w/w) with either sucrose or starch as the carbohydrate source. Animals fed high-fat had higher plasma low-density lipoprotein (LDL) and hepatic cholesterol concentrations than animals fed low-fat diets (P<0.01). The cholesteryl ester content per particle was higher, and the number of triacylglycerol (TAG) molecules was lower in very low density lipoprotein (VLDL) and LDL from animals fed high-fat diets. Intake of high-fat/sucrose resulted in higher plasma LDL concentrations than intake of high-fat/starch, and animals fed low-fat/starch had the highest plasma TAG concentrations associated with VLDL particles containing more TAG molecules, as well as a TAG-enriched LDL. The activity of plasma lecithin cholesteryl:acyl transferase (LCAT) was highest in animals fed high-fat/sucrose, and heart lipoprotein lipase (LPL) activity was higher in animals fed high-fat diets. Hepatic apoprotein B/E (apo B/E) receptor number (B_max) was increased 21% with low-fat diets (P<0.01). These results suggest that the hypercholesterolemia induced by high-fat and by sucrose intake are associated with a higher plasma LCAT activity which results in a cholesteryl ester-enriched VLDL which, by the action of LPL, might be more readily converted to LDL through the delipidation cascade leading to downregulation of hepatic apo B/E receptors. The hypertriglyceridemia associated with low-fat intake may result from increased production of VLDL TAG, which would explain the increased TAG content and the higher TAG/CE ratio of VLDL from animals fed the low-fat/starch diet.     

Wear Behavior of Aluminum Alloys at Slow Sliding Speeds

The investigated slow sliding speeds presented in this work enable the understanding of the wear behavior on aluminum alloys and could possibly facilitate the completion of the previously proposed wear mechanism map for aluminum at this slow sliding speed range. Dry sliding block-on-ring wear tests were carried out on aluminum alloys, AA5754 (Al-Mg), AA6082 (Al-Mg-Si), and AA7075 (Al-Zn-Cu), at a very slow sliding speed range (<0.01 m/s). A bearing steel ring of AISI 52100 was used as the counterbody. Tests were performed at varying contact pressures, 20, 100, and 140 MPa, and sliding speeds ranging from 0.001 to 1.5 m/s. The wear tracks and debris collected were examined by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD), with the aim of analyzing their morphology and composition. At relatively slow sliding speeds (>0.01 m/s), the specimens exhibited a wear process placed at the mild wear regime, characterized by oxidation and delamination mechanisms of both the aluminum specimen and the steel ring. However, at very slow speed range (<0.01 m/s), an increase in the wear rate and the friction coefficient is observed for all of the aluminum alloys, thus suggesting that an alternative wear mechanism could be taking place.     

Vapor characterization of water gel explosives

The vapor components of several water gel explosives have been characterized using Pt-wire preconcentration/capillary gas chromatography; concentration of headspace vapors on Tenax-GC with thermal desorption capillary gas chromatography/mass spectrometry; and liquid chromatography with Thermal Energy Analyzer detection. In addition to normal sensitizing agents almost all of the water gel explosives were found to be contaminated with ethylene glycol dinitrate (EGDN) and nitroglycerine (NG) presumed to occur from storage with dynamites in commerical blasting company magazines. Other trace components are presumed to arise from the manufacturing process.     

Optimising by the response surface methodology the enzymatic elimination of clogging of a microfiltration membrane by pectin cake

The aim of this paper, in which clogging occurs on the filter at a constant vacuum pressure and constant pectin weight, is to find the optimal values of the variables, temperature and time, to know the best conditions to reduce this clogging by enzymatic hydrolysis. Moreover, different properties of the compression of the cake in the filter were determined such as the filtering medium total resistance (R_fT), bed porosity (ε) and the cake‐specific resistance (α) at different times and temperatures. The filter area was 0.142 m², and the value of the mass fraction of solids in the filtered suspension (S) was 0.12. Scanning electron microsopy (SEM) analyses were performed. The results showed that the compressive stress corresponding to the cake improves the flow rate in the filtration flux at the optimal temperature and time for the process, where the enzyme reaches its highest activity. The test results of this study can be applied in different system of filters during cross‐flow filtration.     

Survival of multiple myeloma patients who are potential candidates for early high-dose therapy intensification/ autotransplantation and who were conventionally treated

PURPOSE: To analyze the outcome of patients with multiple myeloma (MM) who were potential candidates for early high-dose therapy (HDT) intensification followed by autotransplantation from a series treated with conventional chemotherapy. PATIENTS AND METHODS: From January 1985 through December 1989, 487 patients with symptomatic MM were entered onto a randomized study to compare melphalan and prednisone (MP) versus vincristine, cyclophosphamide, melphalan, and prednisone (VCMP) /vincristine, carmustine (BCNU), doxorubicin, and prednisone (VBAP). The sub-group of 77 patients who could have been candidates for early intensification with HDT followed by stem-cell support (ie, < 65 years of age, stage II or III disease, performance status < 3, and objective or partial response to initial chemotherapy) are the subjects of this report. RESULTS: Seventy-seven of 487 patients could have been candidates for early intensification. The median age was 56 years (range, 27 to 64). At diagnosis, 12% had abnormal renal function, 16% hypercalcemia, and 42% serum beta 2-microglobulin level > or = 6 mg/L; 62% had stage III disease at diagnosis. Thirty-six patients were initially treated with MP and 41 with VCMP/VBAP. The median response duration to initial chemotherapy was 22 months, and the actuarial probability of being in continued first response at 5 years was 14%. After a median follow-up time of 58 months, 59 patients have died, one was lost to follow-up evaluation, and 17 are still alive 69 to 119 months after initial chemotherapy. The median survival time from initiation of treatment was 60 months and from the time when autotransplantation would be considered, 52 months. The only independent prognostic parameter for survival was renal function at diagnosis. CONCLUSION: The median survival time of patients with MM who are less than 65 years of age and who respond to initial chemotherapy is 5 years. This survival duration is similar to that reported in selected series of patients given early HDT and stresses the importance of ongoing randomized trials to determine the role of HDT in the treatment of younger myeloma patients.