Petrographic and petrophysical characterization of some Paleozoic rocks,Um Bogma area,Southwest Sinai,Egypt

Sixty-two samples were collected from the five formations at Um Bogma area, (Southwest Sinai, Egypt). Nine samples were collected from Sarabit El Khedim Formation, ten samples were collected from Abu Hamata Formation, eighteen samples were collected from Adedia Formation, eight samples were collected from Um Bogma Formation and eighteen samples were collected from Abu Thora Formation.The Paleozoic rocks at Um Bogma area, consist mainly of sandstones, siltstones, shales, limestone and dolostones, which are unconformably overlie igneous and metamorphic rocks (granite, diorite and gneiss) of Precambrian age.The petrographic studies were applied to identify different rock units, different facies and its diagenetic history and to reveal its effect on the storage capacity properties. Different types of porosity (oversized, intergranular, fracture and vuggy porosities) have been identified based on the petrographic investigation of the studied thin sections.The Paleozoic sandstone rock samples are characterized by porosity average about 19% for Facies 1 (quartz wack) and about 18%for Facies 2 (quartz arenite) and permeability average 420?mD for Facies 1 (quartz wack) and 690?mD for Facies 2 (quartz arenite), so these rocks can be considered as good reservoir rocks. The Paleozoic carbonate rock samples (Facies 3) are characterized by poor porosity (less than 7%) and very low permeability (less than 0.5?mD), which caused by matrix and diagenetic processes and refer to bad reservoir rocks.Porosity can be linked to the two derived electrical properties (formation resistivity factor and electrical tortuosity) of the studied Paleozoic rocks at Um Bogma area. The electrical tortuosity has significant effects on both permeability and formation resistivity factor. The permeability decreases with increasing electrical tortuosity and the relation between both of them is inverse relationship with good coefficient of correlation. The permeability decreases with increasing electrical tortuosity and the relations between both of them are inverse relationships with high coefficient of correlation. The formation resistivity factor increases with increasing electrical tortuosity and the relations between both of them are positive relationships with a fair to very high coefficient of correlation.     

Resilient BBU placement in 5G C-RAN over optical aggregation networks

Photonic Network Communications - The huge data demand envisioned for the 5G requires radical changes in the mobile network architecture and technology. Centralized radio access network (C-RAN) is...     

Comparative studies of some local oil seeds and seed cakes

A survey on the chemical constituents (protein, fat, carbohydrates, ash, fibre, calcium, phosphorus, iron) of 4 seeds and their cakes was done. These seeds are safflower seed (Carthamus tinctorius variety Giza 1), sunflower seeds (Helianthus annuus variety Giza 1), linseeds (Linum usitatissimum variety Giza 4) and imported rape seeds (Brassica napus Erglue). Caloric value of these seeds and seed cakes was calculated, PER, NPR and NPU were determined. No great variation was found with respect to the moisture content. The 4 seeds are rich in protein and fat. The ash content varies from (5.11 ± 0.26)% to (3.17 ± 0.13)%. The fiber content was low in both safflower and sunflower seeds and higher in both linseeds and rape seeds. The caloric values of the different seeds were very close. The seeds were found to be rich in phosphorus and low in calcium and contain considerable amounts of iron. The average PER values were 1.51, 1.61, 1.59, 1.84 and 2.50 for safflower seed cake, sunflower seed cake, linseed cake, rape seed cake and casein diet respectively. The average NPR was 3.11, 2.84, 2.84, 3.05 and 3.53 for safflower seed cake, sunflower seed cake, linseed cake, rape seed cake and casein respectively. The NPU values of the seed meals were 48.5, 49.3, 47.4 and 93.6 compared with 67.8 for casein. Using the different criteria (PER, NPR and NPU), it was clear that the protein quality of sunflower seed is very close to that of the linseed. Comparing the protein quality of safflower seed with those of both sunflower and linseed, NPU was in the same range, while PER was somewhat lower and NPR was higher than those of safflower and sunflower seed.     

N-nitrosamines and residual nitrite in cured meats from the Dutch market

Summary A total of 140 samples of 16 kinds of cured meats were analyzed for contents of residual nitrite andN-nitrosamines. Nitrite was determined by reaction with sulfanilamide/naphthylethylenediamine and colorimetric measurement.N-nitrosamines were isolated from the samples by vacuum distillation and determined by gas-chromatography with chemiluminescence detection (GC-TEA). In six samples no nitrite was detectable (< 1 mg NaNO₂/kg), the remaining samples contained 1–140 mg NaNO₂/kg, median value 6.8 mg/kg. In 46 samples (33%) noN-nitrosamines were detected, i.e. less than 0.1–0.5 g/kg of the individual nitrosamines, depending upon their structure.N-nitrosodimethylamine (NDMA) was the nitrosamine present most frequently, in 75 samples, contents were 0.1–0.9 g/kg, mean 0.3 g/kg. OtherN-nitrosamines found were:N-nitrosopiperidine (NPIP), 10 times, 0.3-25 g/kg;N-nitrosodiethylamine (NDEA), three times, 0.2–0.9 g/kg;N-nitrosopyrrolidine (NPYR), three times, 1.3–4.2 g/kg;N-nitrosomorpholine, once, 0.7 g/kg andN-nitrosothiazolidine (NTHZ), 36 times, 0.5–91 g/kg, mean 5.7 g/kg. NTHZ was found most often and with the highest contents in smoked products. Frying of bacon and cured, smoked pork bellies led to substantially increased levels of NPYR in both products, and for the pork bellies also of NTHZ. In five samples of cured, smoked pork bellies after frying NTHZ-contents of 3.6–490 g/kg (mean 179) were found. No correlation between residual nitrite levels andN-nitrosamine contents could be established. Investigations during the nineteen seventies gave much higher levels for NDMA, NDEA, NPIP and NPYR in Dutch cured meats than now found; at that time NTHZ was not measured.

---

N-Nitrosamine und Restnitrit in holländischen Fleischerzeugnissen

Zusammenfassung Insgesamt wurden 140 Proben von 16 verschiedenen Fleischerzeugnissen auf ihren Gehalt an Restnitrit und flüchtigenN-Nitrosamine geprüft Nitrit wurde nach Reaktion mit Sulfanilamid/Naphthylethylendiamin colorimetrisch bestimmt.N-Nitrosamine wurden mittels Vakuumdestillation aus den Proben isoliert und mit Gaschromatographie-Chemiluminescenzdetektion (GC-TEA) gemessen. In 6 Proben war kein Nitrit nachweisbar (< 1 mg NaN0₂/kg), die Nitritgehalte der übrigen Proben lagen zwischen 1 und 140 mg NaNO₂/kg, Medianwert 6,8 mg/kg. In 46 Proben (33%) waren keineN-Nitrosamine nachweisbar d.h. weniger als 0,1–0,5 g/kg.N-Nitrosodimethylamin (NDMA) kam am häufigsten vor, in 75 Proben mit Gehalten von 0,1–0,9 g/kg, Mittelwert 0,3 g/kg. Von den sonstigen Nitrosaminen waren nachweisbar:N-Nitrosopiperidin (NPIP), 0,3–25 g/kg (zehnmal);N-Nitrosodiethylamin (NDEA), 0,2–91 g/kg (dreimal),N-Nitrosopyrrolidin (NPYR), 1,3–4,2 g/kg (dreimal),N-Nitrosomorpholin (NMOR), 0,7 g/kg (einmal) undN-Nitrosothiazolidin (NTHZ), 0,5–91 g/kg (36mal), Mittelwert 5,7 g/kg. NTHZ wurde am häufigsten und mit den höchsten Mengen in geräucherten Produkten gefunden. Braten von Bacon und Frühstückspeck erhöhte die Gehalte an NPYR erheblich in beiden Produkten und bei Frühstückspeck auch den Gehalt an NTHZ. In 5 Proben Frühstückspeck wurden nach dem Braten NTHZ-Gehalte von 3,6–490 g/kg (Mittelwert 179) gemessen. Es konnte keine Beziehung zwischen den Gehalten an Restnitrit undN-Nitrosaminen festgestellt werden. Untersuchungen in den siebziger Jahren ergaben viel höhere Gehalte an NDMA, NDEA, NPIP und NPYR in holländischen Fleischwaren als die jetzt gefundenen; auf NTHZ wurde damals nicht analysiert.

     

The antioxidant activity of amino acids in two vegetable oils

Of 27 amino acids studied, most had some antioxidant activity when added in aqueous solution to either safflower oil or a mixture of sunflower and cottonseed oil (active oxygen and storage methods). Cysteine-HCl, glutamic acid-HCl (in the mixture), and glutamic acid-HCl (in safflower oil) behaved as prooxidants. When added as a solid, most amino acids were ineffective. The protection factors of these amino acids were less than 1.3 in safflower oil with methionine, proline, lysine and cysteine providing the highest activ-ity. In the oil mixture (which had a higher metal content) lysine, arginine, glutamic acid, methionine, and hydroxyproline were anti-oxidant with protection factors of up to 1.85. Chelation of metals by amino acids was presumably responsible for the antioxidant activity. The increase in cysteine concentration up to 1% has more than doubled the protection factor in Bint oil (compared with the 0.01% level), whereas with some other amino acids the increase was either small or slight.     

Occurrence of 5α-cholesta-7,24-dien-3β-ol and 23-dehydrolophenol in the bean lipids of Vanilla madagascariensis

Eleven 4-desmethylsterols, four 4,4-dimethylsterols, and twelve 4-methylsterols were identified in Vanilla madagascariensis beans. The 4-desmethylsterol fraction was characterized by a high level of 5α-cholesta-7,24(25)-dien-3β-ol (35.3%). The 4-methylsterol fraction was characterized by a high level of 31-norcycloartenol (57.5%) and the presence of 23-dehydrolophenol (9.4%). Cycloartenol (72.9%), cyclosadol (12.7%), parkeol (9.7%), and 24-dehydrotirucallol (4.7%) were identified in the 4,4-dimethylsterol fraction.     

Effects of processing on oxidative stability of sesame oil extracted from intact and dehulled seeds

Oxidative stability of oils extracted from intact and dehulled sesame seeds was determined by monitoring changes in fatty acid composition, iodine value (IV), peroxide value (PV), conjugated diene (CD), para-anisidine value (p-AV), and 2-thiobarbituric acid (TBA) value and by nuclear magnetic resonance spectroscopy after storage under Schaal oven conditions at 65°C for up to 35 d. The oils from coated seeds were more stable, as reflected in PV, CD, p-AV and TBA values, than those extracted from dehulled seeds after roasting at 200°C, steaming at 100°C, roasting at 200°C plus steaming, or microwaving at 2450 MHz, except for TBA values of oil from microwaved seeds. After 35 d of storage at 65°C, the CD, p-AV, and TBA values of extracted oil from dehulled microwaved seeds were 17.72, 10.20, and 1.22, respectively, while those of their coated counterparts were significantly (P<0.05) different at 14.20, 16.47, and 1.26, respectively. Few significant changes were evident in the fatty acid composition of oil obtained from either coated and dehulled seeds subjected to different treatments. Nuclear magnetic resonance analyses found that R_ao (aliphatic to olefinic protons) and R_ad (aliphatic to diallylmethylene protons) ratios increased steadily over the entire storage period, which indicated progressive oxidation of unsaturated fatty acids.     

Mapping local microstructure and mechanical performance around carbon nanotube grafted silica fibres: methodologies for hierarchical composites

The introduction of carbon nanotubes (CNTs) modifies bulk polymer properties, depending on intrinsic quality, dispersion, alignment, interfacial chemistry and mechanical properties of the nanofiller. These effects can be exploited to enhance the matrices of conventional microscale fibre-reinforced polymer composites, by using primary reinforcing fibres grafted with CNTs. This paper presents a methodology that combines atomic force microscopy, polarised Raman spectroscopy, and nanoindentation techniques, to study the distribution, alignment and orientation of CNTs in the vicinity of epoxy-embedded micrometre-scale silica fibres, as well as, the resulting local mechanical properties of the matrix. Raman maps of key features in the CNT spectra clearly show the CNT distribution and orientation, including a 'parted' morphology associated with long grafted CNTs. The hardness and indentation modulus of the epoxy matrix were improved locally by 28% and 24%, respectively, due to the reinforcing effects of CNTs. Moreover, a slower stress relaxation was observed in the epoxy region containing CNTs, which may be due to restricted molecular mobility of the matrix. The proposed methodology is likely to be relevant to further studies of nanocomposites and hierarchical composites.     

Rheological studies of the cure of epoxy/polyester powder coatings containing titanium dioxide

The cure characteristics of a series of powder coatings containing titanium dioxide dispersed in an epoxy/polyester matrix are reported. The titanium dioxide pigments were produced via both the chloride and sulfate routes and coated with varying amounts of alumina and silica. Comparison data for formulations containing zinc oxide and silica are also included. The time to gelation for these powder coatings depends on a number of factors. Increasing the level of flow agent significantly reduces the time to gelation. The presence of traces of zinc inhibits cure in the case of the sulfate-based pigments. Varying levels of alumina and silica in the coating on the titanium dioxide coating also influence the time to gelation. Increasing the level of silica on the chloride-based coating increases the time to gelation, whereas in the case of the sulfate based coating the time to gelation is shortened. These differences are attributed to the effects of zinc in the coating and the effectiveness of the dicyandiamide catalysts.