Isobaric thermal expansivities of mixtures ofm-cresol and quinoline from 0.1 to 400 MPa at 303 to 503 K

Isobaric thermal expansivities, α _p (p, T), of five binary mixtures ofm-cresol with quinoline (0.1499, 0.2998, 0.5005, 0.6325, and 0.8501 mol fraction ofm-cresol) were measured in a pressure-controlled scanning calorimeter over the pressure range from just above the saturation vapor pressures to 400 MPa, and at 303.15, 353.15, 403.15, 453.15, and 503.15 K. Molecular association ofm-cresol with itself and ofm-cresol with quinoline exerts large effects on the pressure and temperature behavior of α _p isotherms. The extent of association changes significantly with conditions in all except the 2∶1 mixture as demonstrated by the crossing of isotherms at lower pressures as the temperature increases. In the 2∶1m-cresol quinoline mixture the extent of association is not perturbed significantly by temperature change and the mixture behaves like a simple liquid, exhibiting a unique crossing point of α _p isotherms.     

Model fuel desulfurization and denitrogenation using copper and cerium modified mesoporous material (MSU-S) through adsorption process

The application of MSU-S, CeO₂-MSU-S, and Cu₂O-MSU-S in desulfurization and denitrogenation of model fuel containing benzothiophene (BT), dibenzothiophene (DBT), quinoline and carbazole were studied in batch and continuous process. The copper-modified MSU-S showed the highest capacity to adsorb sulfur and nitrogen compounds compared to other adsorbents. The adsorption selectivity of all adsorbents for nitrogen was slightly higher than for sulfur, indicating the selective adsorption of nitrogen over sulfur. The Langmuir model represented better equilibrium data fitting than Freundlich model for carbazole, DBT, and BT adsorption on MSU-S, CeO₂-MSU-S, and Cu₂O-MSU-S. It was found that quinoline adsorption data on MSU-S, CeO₂-MSU-S, and Cu₂O-MSU-S can be presented by Freundlich model very well. The kinetics of adsorption followed the pseudo-second-order model for all species over each adsorbent. According to the breakthrough curve order, the adsorptive selectivity for the adsorbates increased in the order of DBT < BT < carbazole < quinoline for MSU-S and CeO₂-MSU-S, and BT < DBT < carbazole < quinoline for Cu₂O-MSU-S.     

Life in oil: Hydrocarbon-degrading bacterial mineralization in oil spill-polluted marine environment

The biodegradation of hydrocarbons by microorganisms is one of the primary ways by which an oil spill is eliminated from contaminated sites. One such spill was that of the Russian tanker the Nakhodka that spilled heavy oil into the Sea of Japan on January 2, 1997. This paper describes the three main processes of the Nakhodka oil spill, including: (1) the weathering of hydrocarbon-degrading bacteria (genus Pseudomonas) and crystallized organic compounds from the Nakhodka oil spill-polluted seashores after nine years; (2) the laboratory-scale biodegradation of the Nakhodka oil spill over a 429-day period; and (3) the bioavailability of kaolinite clay minerals and the role they play in seawater polluted with the Nakhodka oil spill. Upon the slow evaporation of the Nakhodka oil spill during the 9-year weathering, the dendritic crystal growth of paraffin (a mixture of alkanes) occurred in the oil crust under natural conditions. Heavy metals were obtained in the original heavy oil samples of three seashores in the Sea of Japan. Si, S, Ti, Cr, Ni, Cu, and Zn were found in the original Nakhodka oil spill samples whereas these heavy metals and S were no longer present after 9 years. The anaerobic reverse side of the oil crust contained numerous coccus-type bacteria associated with halite. The hydrocarbon-degrading bacteria and paraffin wax in the oil crust may have a significant effect on the weathering processes of the Nakhodka oil spill during the 9-year bioremediation. A biodegradation process of heavy oil from the Nakhodka oil spill by indigenous microbial consortia was monitored over 429 days in the laboratory. The indigenous microbial consortia consisted of bacteria and fungi as well as the bacterium Pseudomonas aeruginosa isolated from Atake seashore, Ishikawa Prefecture, Japan. Both bacteria and fungi had a significant role in the observed biodegradation of heavy oil during the 429-day bioremediation with respect to the pH of the solution. Hydrocarbon-degrading bacteria had a tendency to play the greatest role under neutral to alkaline condition (pH; 7–7.8). On the contrary, when pH shifted to acidic (pH; 2–4) levels, the fungi took over to degrade heavy oil. During the period, the aliphatic hydrocarbons were reduced significantly but the aromatic hydrocarbons remained relatively constant even after 429 days of bioremediation. Experimental study was undertaken to investigate the bioavailability of kaolinite clay minerals and the role they play in seawater polluted with the Nakhodka oil spill. TEM/EDS imaging suggested that the clays present in oil-polluted seawater were capable of stimulating oil-degrading bacteria probably because Si from clays facilitates bacterial usage of oil and C-O-Na-Si complexes on the surfaces of bacterial cell walls are a stimulator for oil-degrading bacterial growth in seawater contaminated with the Nakhodka oil spill.     

Influence of organic and inorganic compounds on oxidoreductive decolorization of sulfonated azo dye C.I. Reactive Orange 16

An isolated bacterial strain is placed in the branch of the Bacillus genus on the basis of 16S rRNA sequence and biochemical characteristics. It decolorized an individual and mixture of dyes, including reactive, disperse and direct. Bacillus sp. ADR showed 88% decolorization of sulfonated azo dye C.I. Reactive Orange 16 (100 mg L⁻¹) with 2.62 mg of dye decolorized g⁻¹ dry cells h⁻¹ as specific decolorization rate along with 50% reduction in COD under static condition. The optimum pH and temperature for the decolorization was 7–8 and 30–40 °C, respectively. It was found to tolerate the sulfonated azo dye concentration up to 1.0 g L⁻¹. Significant induction in the activity of an extracellular phenol oxidase and NADH–DCIP reductase enzymes during decolorization of C.I. Reactive Orange 16 suggest their involvement in the decolorization. The metal salt (CaCl₂), stabilizers (3,4-dimethoxy benzyl alcohol and o-tolidine) and electron donors (sodium acetate, sodium formate, sodium succinate, sodium citrate and sodium pyruvate) enhanced the C.I. Reactive Orange 16 decolorization rate of Bacillus sp. ADR. The 6-nitroso naphthol and dihydroperoxy benzene were final products obtained after decolorization of C.I. Reactive Orange 16 as characterized using FTIR and GC–MS.     

The <Emphasis Type="Italic">α–β</Emphasis> Transition of Nitrogen

It is well-known that, aside from its triple point, nitrogen exhibits a solid-to-solid transition at about 35 K that is of some interest as a secondary reference temperature. During the recently published highly accurate measurements of the triple point of nitrogen (Metrologia 43, 435 (2006)), an extensive study was made also of the solid α–β transition of nitrogen, using both the continuous heating method and the pulse-heating method. This transition is of significantly lower quality than the triple point of nitrogen. A very high thermal resistance and a large time constant characterize the transition. Therefore, even the determination of the self-heating of the thermometer requires a very long time. A value of T ₉₀ = 35.620 K with an expanded uncertainty U = 8 mK for the coverage factor k = 2 was found, differing by +6 mK from the published CCT-recommended value. The reproducibility of the value was better than ± 5 mK. In addition to the temperature value found for the transition, a comparison is made with previous measurements on this point, and an overview is given of the available information about it.     

Monitoring of population shifts in an enriched nitrifying system under gradually increased cadmium loading

The changes in nitrifying bacterial population under cadmium loading were monitored and evaluated in a laboratory scale continuous-flow enriched nitrification system. For this purpose, the following molecular microbiological methods were used: slot–blot hybridization, denaturing gradient gel electrophoresis (DGGE), real-time PCR followed by melting curve analysis, cloning and sequence analysis. The initial cadmium concentration was incrementally increased from 1 to 10 mg/l which led to a drop in ammonia removal efficiency from 99 to 10%. Inhibition was recovered when cadmium loading was stopped. During the second application of cadmium, nitrifying population became more tolerant. Even at 15 mg/l Cd, only a minor inhibition was observed. To investigate the variations in ammonia and nitrite oxidizing bacteria populations in a period of 483 days, ammonia monooxygenase (amoA) and 16S rRNA genes-based molecular techniques were used. An obvious shift was experienced in the diversity of ammonia oxidizers after the first application of 10 mg/l Cd. Metal-tolerant ammonia oxidizing species became dominant and the microbial diversity sharply shifted from Nitrosomonas and Nitrosococcus sp. to Nitrosospira sp. which were observed to tolerate higher cadmium loadings. This result indicated that the extent of nitrification inhibition was not only related to the metal concentration and quantity of microorganisms but also depended on the type of species.     

The fracture toughness of polybutadiene and other elastomers in cold nitrogen gas

The fracture toughness of crosslinked polybutadiene was measured using the double torsion method, with chilled nitrogen gas as the environment. High fracture energies were found as the gas temperature approached the nitrogen boiling point (77K). As temperature increased to 115 K,G _lc decreased from about 7 to 1 kJm^–2. Above this temperature, fracture toughness increased again, but no reliable data could be gained by this method, when the temperature exceeded 135 K. The range of fracture toughness observed for this polymer is about one half that previously recorded, using liquid nitrogen. Crooa!ink density has a modest effect upon fracture toughness. Strain crystallizing natural rubber and non-strain crystallizing polyisobutyiene rubber were either lightly or heavily crosslinked, and the fracture toughness also measured in nitrogen at 95 and 125 K. Again,G _lc decreased at the higher temperature for both polymer types, but -the natural rubber was significantly tougher than the polybutadiene, whilst the polyiombutyiena was more fragile.     

Feasibility of <Emphasis Type="Italic">m</Emphasis>-cresol degradation using an indigenous mixed microbial culture with glucose as co-substrate

An indigenous mixed culture of microorganisms, isolated from the soil of a gasoline filling station, was used in degrading m-cresol in presence of glucose as an alternative carbon source. Initial glucose concentration was kept at either 250 or 500 mg l⁻¹, to initiate and support necessary culture growth, and that of m-cresol was varied between 50 and 400 mg l⁻¹. A maximum total biomass yield value of 0.925 g g⁻¹ was obtained at 100 mg l⁻¹ m-cresol and 500 mg l⁻¹ glucose initial concentrations in the media. Variation in the experimentally observed specific growth rate revealed that m-cresol initial concentrations, above 100 mg l⁻¹, inhibited the culture growth irrespective of the glucose concentrations used in the study. Complete degradation of m-cresol was observed within a time period of 18–26 h depending upon the initial concentrations of m-cresol and glucose in the media; on the other hand, glucose utilization was quick and preceded m-cresol degradation. A sum kinetics model was used to describe the variation in the culture specific growth rate, which gave a high coefficient of determination (R ²) value >0.98. From the interaction parameter values obtained by solving this model, the inhibitory effect of glucose on m-cresol degradation by the culture was found to be more pronounced compared to the effect of m-cresol on glucose utilization. This study showed good potential of the indigenous mixed culture in degrading m-cresol when it is provided with a simple alternative carbon source, such as glucose, for supporting its growth.     

Constraint-modified J−R curves and its application to ductile crack growth

The concept of J-controlled crack growth is extended to J–A ₂ controlled crack growth using J as the loading level and A ₂ as the constraint parameter. It is shown that during crack extension, the parameter A ₂ is an appropriate constraint parameter due to its independence of applied loads under fully plastic conditions or large-scale yielding. A wide range of constraint level is considered using five different types of specimen geometry and loading configuration; namely, compact tension (CT), three-point bend (TPB), single edge-notched tension (SENT), double edge-notched tension (DENT) and centre-cracked panel (CCP). The upper shelf initiation toughness J _IC, tearing resistance T _R and J–R curves tested by Joyce and Link (1995) for A533B steels using the first four specimens are analysed. Through finite element analysis at the applied load of J _IC, the values of A ₂ for all specimens are determined. The framework and construction of constraint-modified J–R curves using A ₂ as the constraint parameter are developed and demonstrated. A procedure of transferring the J–R curves determined from standard ASTM procedure to non-standard specimens or practical cracked structures is outlined. Based on the test data, the constraint-modified J–R curves are presented for the test material of A533B steel. Comparison shows the experimental J–R curves can be reproduced or predicted accurately by the constraint-modified J–R curves for all specimens tested. Finally, the variation of J–R curves with the size of test specimens is produced. The results show that larger specimens tend to have lower crack growth resistance curves.     

Effect of packaging materials and storage conditions on bacterial growth,off‐odour,pH and colour in chicken breast fillets

A comparison was made of the effect of different packaging materials on bacterial growth, off‐odour, pH and colour of chicken breast fillets stored at 4°C. For one of the packaging materials, the effects of temperature (4°C and 8°C) and initial oxygen present (0%, 2% and 4%) on bacterial growth, off‐odour, pH and colour in chicken breast fillets were also evaluated. Chicken breast fillets stored in the packaging material with the highest oxygen transmission rate (OTR) measured at actual storage conditions had the highest bacterial growth and the highest degree of off‐odour. Chicken breast fillets stored in packaging material mainly consisting of expanded PET had similar bacterial growth and off‐odour as in the barrier display film (BDF) packages, despite a smaller headspace volume and lower initial concentration of CO₂. No differences in discoloration and pH of the chicken breast fillets, due to storage temperature and amount of initial oxygen present, were found when one of the packaging materials was studied. In the early phase of the storage period, Pseudomonas spp. constituted the majority of the total viable counts, while after about 12 days, lactic acid bacteria dominated. At the end of the storage period, both Pseudomonas spp. and Enterobacteriaceae were present in high numbers. Significant differences in counts of Brochothrix thermosphacta were only obtained with initial presence of oxygen. The storage temperature had greater impact on microbial growth and off‐odour than the initial presence of oxygen in the packages. Copyright © 2004 John Wiley & Sons, Ltd.     

Effect of fracture path on the toughness of weld metal

The crack propagation direction may affect weld metal fracture behavior. This fracture behavior has been investigated using two sets of single edge notched bend (SENB) specimens; one with a crack propagating in the welding direction (B×2B) and the other with a crack propagating from the top in the root direction (B×B) of a welded joint. Two different weld metals were used, one with low and one with high toughness values. For Weld Metal A, two specimen types have been used (B×B and B×2B) both with deep cracks. The weld metal A (with high toughness values) has reasonably uniform properties between weld root and cap. The resulting J-R curves show little effect of the specimen type, are ductile to the extent that the toughness exceeds the maximum J_max, value allowed by validity limits and testing is in the large –scale yielding regime. In the case of weld metal B (with low toughness values) with two specimen types (B×B and B×2B) the B×B specimen has shallow cracks while the B×2B specimen has deep cracks. Both resulting J-R curves show unstable behavior despite the fact that the types of specimen and their constraints are different. The analysis has shown that crack propagation direction is most influential for a weldment with low toughness in the small scale yielding regime, whereas its influence diminishes due to ductile tearing during stable crack growth and large scale yielding. The results have shown that these effects are different in both the crack initiation phase and during stable crack growth, indicating a dependence on weld metal toughness and the microstructure of the weld metal. It can be concluded that, if resistance curves during stable crack growth do not show differences in both notch orientations, the fracture toughness values of the whole weld metal can be treated as uniform.     

Effect of Micro-Phase Separation on Magnetic Response in Pr-Doping YBa2Cu3O7−δ Single Crystals

Pr-doping Y_0.928Pr_0.072Ba₂Cu₃O_7−δ superconducting single crystal was studied systemically by the magnetic response measurement below T _c . DC magnetization shows a possible existence of micro-phase separation caused by the non-uniform distribution of Pr ions in microstructure during the growth procedure. The magnetic field dependence of critical current density J _c and pinning force density F _p had been obtained from the magnetization hysteresis loop. Flux pinning mechanisms in different magnetic fields had been discussed using the scaling function as well as the ratio of the pinning force field at H _on and H _peak. We find that the peak effect is influenced by the micro-phase separation which is caused by the non-uniform distribution of Pr ions in microstructure during the growth procedure. The interface between the different T _c superconductivity areas can be the effective pinning center which is useful to the appearance of peak effect. The value of the ratio of the maximum pinning force field to the irreversibility field is discussed. The conclusion is consistent with the model constructed by Wen et al.; we finally draw out the thermomagnetic phase diagram for our samples.      

Phytofiltration of cadmium from water by Limnocharis flava (L.) Buchenau grown in free-floating culture system

A hydroponics experiment was conducted to examine the phytofiltration of Cd by Limnocharis flava (L.) Buchenau grown in low-level Cd-contaminated water. For this, 45 d old seedlings of L .flava were transferred to a floating-support culture system containing nutrient solution spiked with four levels of Cd (0.5, 1, 2 and 4 mg l⁻¹) and were separately harvested after 3, 7, 21 and 30 d. After 30 d harvesting, the percentage removal of Cd from the above four treatments reached up to 98, 96, 95 and 93%, respectively. Interestingly, all treatments had higher growth rate than control at 95% confidence level and plants still remained healthy at 4 mg l⁻¹ Cd exposure. The bioaccumulation study showed a linear relationship of Cd (R² = 0.896–0.999) in all plant parts with the exposure time (3–30 d) and Cd concentrations in hydroponics system (0.5–4 mg l⁻¹). Although, the root of L. flava had higher Cd concentration than leaf and peduncles, the total Cd concentrations in aerial plant parts were higher than the roots. The maximum bioconcentration factor (BCF) and translocation factor (TF) value of L. flava were calculated as 984.42 and 1.43, respectively. Estimated Cd accumulation capacity of L. flava per unit area (m²) was found to be in the range of 218. 35–1698.92 mg m⁻².The experimental results demonstrated that L. flava is a suitable candidate for the phytofiltartion (>93%) of Cd from low-level Cd-contaminated water.     

Role of metal resistant plant growth promoting bacteria in ameliorating fly ash to the growth of Brassica juncea

In this study, we have shown that the plant growth promoting bacterial strain NBRI K24 and strain NBRI K3 from fly ash (FA) contaminated soil reduce the toxicity of Ni and Cr in Brassica juncea (Indian mustard) and promote plant growth under pot culture experiments. Isolated strains NBRI K24 and NBRI K3 were characterized based on the 16S rDNA sequencing and identified as Enterobacter aerogenes and Rahnella aquatilis respectively. Both the strains were siderophore producing and found capable of stimulating plant biomass and enhance phytoextraction of metals (Ni and Cr) from FA by metal accumulating plant i.e. B. juncea. Concurrent production of siderophores, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, indole acetic acid (IAA) and phosphate solubilization revealed their plant growth promotion potential.     

Ecotoxicological screening of reclaimed disinfected wastewater by Vibrio fischeri bioassay after a chlorination–dechlorination process

It is well known that different substances can react with chlorine in a water disinfection process to produce disinfection by-products (DBPs). Some of these substances have proven to be carcinogenic in humans and animals. Because it is not possible to detect all DBPs produced in chlorinated wastewater, toxicity tests have been proposed as a useful tool for screening toxic chemicals in treated wastewater. In this study, the Microtox^® bioassay with Vibrio fischeri was used to evaluate the formation of toxic by-products in wastewater, after a chlorination–dechlorination disinfection treatment. All the variables were found to be normally distributed, so analysis of variance could be directly applied without transformation of variables. Significant correlations were obtained between toxicity values and total carbon, total inorganic carbon, total nitrogen, chlorine, and pH. In contrast, total organic carbon, chemical oxygen demand, electrical conductivity and turbidity had no effect on toxicity formation. Toxicity increased with the Cl₂:NH₄⁺ ratio at a higher chlorine concentration released from combined chlorine. Regression models provided a good fit for effective concentration (EC50) as a function of total carbon and total nitrogen, after 5, 10, and 15 min of exposure. These models had greater multiple determination coefficients than previously reported for similar studies, without autocorrelation in the residuals as indicated by the Durbin–Watson statistic test. The measured and predicted ecotoxicity values were strongly correlated.     

Treatment of textile effluent using bacteria-immobilized graphene oxide nanocomposites: evaluation of effluent detoxification using <Emphasis Type="Italic">Bellamya bengalensis</Emphasis>

Recent studies have reported graphene-based nanomaterials as novel scaffolds for the development of vigorous biocatalytic systems. The present study investigated polyacrylic acid-linked graphene oxide (GO)–gelatin nanocomposite for the immobilization of moderately halotolerant engineered bacterial consortium consisting of Dietzia sp., Bacillus sp. and Pseudomonas mendocina. This biocatalyst was subsequently applied for treatment of hypersaline textile effluents collected from local textile manufacturing and processing units. Effluent treatment efficiency of this biocatalyst was assessed in terms of its dye, surfactant and salt-removal abilities from collected effluents. High metabolic activity recorded in the case of immobilized bacterial cells indicated that immobilization had stimulated improved growth as well as electrolyte and pH tolerance in bacterial cells. Examination of the treated effluents suggested approximately 99% removal of COD, color (dyes), electrolytes and surfactant. Probable cyto-genotoxic potential and oxidative stress inducing the ability of both untreated and treated effluents was determined with Bellamya bengalensis (fresh water snail). Comet formation in hepatopancreatic cells of snails exposed to untreated effluent was significantly higher than in individuals exposed to treated effluents which in turn were similar to organisms treated as control. Hence, results of this study indicated efficient performance of GO-based biocatalyst in augmenting biodegradation and detoxification of textile effluent. The low cost incurred during the synthesis and application of bacteria-immobilized GO nanocomposite and its reusability potential determined herein established the process of effluent treatment reported in this study as a promising approach for commercial wastewater treatment.     

Combined effect of chill storage and modified atmosphere packaging on mussels (Mytilus galloprovincialis) preservation

Changes in biochemical indices, microbial growth, headspace and sensory quality of mussels which had been packaged in two modified atmospheres [Modified atmosphere packaging (MAP) 1: 60% CO₂/20% N₂/20% O₂ and MAP 2: 60% CO₂/40% N₂] and under vacuum (VP) were studied for 14 days. The results showed better quality retention and greater shelf life of mussels packaged under MAP 1 as compared to MAP 2 and VP samples. Increase in total volatile basic nitrogen followed the order: MAP 1 < MAP 2, VP < air (control) samples while increase in trimethylamine nitrogen followed the order: MAP 1 < air < MAP 2 < VP. The 2‐thiobarbituric acid (TBA) values of MAP 1 and air samples were significantly higher (p < 0.05) than the TBA values of VP and MAP 2 samples. MAP 1 showed a greater (p < 0.05) inhibition effect on total viable count of mussel samples than all other packaging conditions. Based primarily on odour scores, the MAP 1 samples remained acceptable up to ca. 10–11 days, the MAP 2 and VP up to ca. 7–8 days while the air‐packaged samples up to ca. 5–6 days of storage. Copyright © 2007 John Wiley & Sons, Ltd.     

Effects of Au/Fe and Fe nanoparticles on Serratia bacterial growth and production of biosurfactant

The overall objective of this study was to compare the effects of Au/Fe and Fe nanoparticles on the growth and performance of Serratia Jl0300. The nanoparticle effect was quantified not only by the bacterial growth on agar plate after 1 hour interaction with the nanoparticles, but also by its production of a biosurfactant from used vegetable oil. The nanoparticles were prepared using the foam method. The concentrations of the nanoparticles used for the bacterial interaction study were varied from 1 mg/L to 1 g/L. The test results showed that the effect of nanoparticles on the bacterial growth and biosurfactant production varied with nanoparticle type, concentrations, and interaction time with the bacteria. Au/Fe nanoparticles didn't show toxicity to Serratia after short time (1 h) exposure, while during 8 days fermentation Au/Fe nanoparticles inhibited the growth of Serratia as well as the biosurfactant production when the concentration of the nanoparticles was higher than 10 mg/L. Fe nanoparticles showed inhibition effects to bacterial growth both after short time and long time interaction with Serratia, as well as to biosurfactant production when its concentration was higher than 100 mg/L. Based on the trends observed in this study, analytical models have been developed to predict the bacterial growth and biosurfactant production with varying concentrations of nanoparticles.     

A comparative study of the physical and mechanical properties of three natural corals based on the criteria for bone–tissue engineering scaffolds

Coral has been used for bone grafts since 1970. Because coral has the advantages of good osteoconduction, biocompatibility, and biodegradation, it is also suitable for scaffolds used in bone–tissue engineering. However, the skeletons of different species of corals often vary significantly, and very few studies focus on the assessment of the permeability and mechanical properties of coral structure. In order to better understand the use of coral in bone tissue–engineering, we selected three typical models (Acropora sp., Goniopora sp., and Porites sp.) to analyze for pore size, porosity, permeability, and mechanical strength. We found Goniopora and Porites had homogenous structure and Acropora had oriented pores and irregular pore size. Acropora had the largest permeability, however, the transverse section was closed and the useful size was limited because of its habitat type. Porites had the smallest pore size and had the lowest permeability. Our data indicated that Goniopora sp. can be considered as the most promising source of scaffolds for bone–tissue engineering because of its high porosity (73%) and that its permeability and mechanics were similar to those in human cancellous bone. In conclusion, we analyzed the impact of the macroporous structure of coral on the permeability and mechanical properties that provide indicators for designing the optimal scaffold for bone–tissue engineering.     

Influence of the Preservation Process on the Quality of Carp Fillets

An investigation was carried out on the microbiological quality of carp fillets linked to slaughtering methods, variation in temperature, storage time and packing as well as recording the main bacterial flora (total aerobic bacteria, Enterobacteria and Pseudomonas sp. and lactic acid bacteria). The results of this study showed the following. (i) The working room temperature (5–18°C) and dipping of the fillets in ice water did not have any influence on the microbiological quality of the carp fillets. However, for industrial purposes it would be more adequate to work at low temperature. (ii) The packaging process (air, vacuum or modified atmosphere) had significant effects on the microbiology of the fillets. (iii) Only those fillets under a modified atmosphere offered a shelf-life of 10 days or more (up to 14 days). (iv) MA packaging with 50% CO₂ gave the best results with regard to limiting microbiological growth. (v) Storage of the fillets at a temperature higher than 3°C should be prohibited as well as potential breaks in the cold chain.