Geology and potentiality of basalts in Jabal Eghei area (Libya) : doctoral dissertation

Bazalti pokrivaju veći deo područja Jabal Eghei i deo su vulkanske provincije Tibesti. To su stratifikovani bazalti, izliveni preko proterozojskih metamorfita i granita i preko litološki različitih stena tercijarne starosti. Nastali tokom tri odvojene faze vulkanske aktivnosti u periodu između 12 i 8 Ma (I faza), 7- 4 Ma (II faza) i mlađe od 4 Ma (III faza). Osnovni minerali u bazaltima prema zastupljenosti su olivin, klinopiroksen i plagioklas, a od sporednih se javljaju minerali iz grupe spinela (magnetit ± ilmenit) i ostaci vulkanskog stakla. U bazaltima treće vulkanske faze utvrđeno je i prisustvo analcimiziranih leucita, analcima i renita, koji do sada nisu bili dokazani na ispitivanom području. Preovlađujuće strukture su porfirska i ofitska, a teksture masivna i vezikularna. Fizičko-mehanička svojstva bazalta su u očekivanim granicama, a sa geomehaničke tačke gledišta ispitivani bazalti su dosta homogeni. Iz rezultata tih proučavanja i ispitivanja metodom ultrazvuka, može se zaključiti da bazalti porfirske strukture i masivne teksture pokazuju najbolja svojstva sa aspekta kvaliteta kamena kao stenske mase. Bazaltni prah kao punilo testiran je sa aspekta mogućnosti pripreme kompozitnog materijala pogodnog za izlaganje kavitaciji, a rezultati pokazuju da hibridni kompozitni materijal koji se sastoji od bazaltnog praha i čestica glinice ima poboljšanu kavitacijsku otpornost u odnosu na čistu matricu i mikro kompozit koji se sastoji od bazaltnog praha i materijala matriksa. Ovaj materijal, pored toga, ima veoma dobra estetska svojstva i svojstva materijala otpornog na abraziju. Kod ocene potencijalnosti izdvojene su tri rudne formacije, koje obuhvataju bazalte sve tri vulkanske faze. Sa aspekta ukupne potencijalnosti područje Jabal Eghei predstavlja područje velike potencijalnosti za otkrivanje, istraživanje i definisanje budućih ležišta bazalta kao rudnih formacija velikog rasprostranjenja i dobrih kvalitativnih karakteristika, bilo da se radi o građevinskom kamenu, sirovini za bazaltna vlakna i kompozitne materijale.Basalts cover most of the Jabal Eghei area and are part of the Tibesti volcanic province. These are stratified basalts, covering Proterozoic metamorphites and granites and lithologically different rocks of Tertiary age. Basalts were formed during three separate phases of volcanic activity between 12 and 8 Ma (Phase I), 7- 4 Ma (Phase II) and less than 4 Ma (Phase III). The most abundant minerals in basalts are olivine, clinopyroxene and plagioclase, while the minor minerals are from the spinel group (magnetite ± ilmenite) and volcanic glass residues. In the basalts of the third volcanic phase, the presence of analcimitised leucite, analcime and rhoenite was detected, which has not been proven in the studied area so far. The predominant textures are porphyric and ophitic, while the structures are massive and vesicular. The physico-mechanical properties of basalt are within the expected limits, and from a geomechanical point of view, the tested basalts are quite homogeneous. From the results of these studies and tests by ultrasonic method, it can be concluded that the basalts of porphyric texture and massive structure exhibit the best properties in terms of stone quality as a rock mass. Basalt powder as a filler has been tested for the possibility of preparing a composite material suitable for cavitation exposure, and the results show that a hybrid composite material consisting of basalt powder and alumina particles has improved cavitation resistance over a pure matrix and a micro composite consisting of basalt powder and matrix material. This material has also very good aesthetic and abrasion-resistant properties. In the assessment of potentiality, three ore formations were identified, comprising basalts of all three volcanic phases. In terms of overall potential, the Jabal Eghei area is a high potential area for the discovery, exploration and definition of future basalt deposits as ore formations of large extent and of good qualitative characteristics, whether as building stone, basalt fiber raw materials and composite materials

Relationship between serum thyrotropin and urine albumin excretion in euthyroid subjects with diabetes

Background Microalbuminuria represents vascular and endothelial dysfunction. Thyroid hormones can influence urine albumin excretion as it exerts crucial effects on the kidney and on the vascular system. This study explores the relationship between serum thyrotropin and urine albumin excretion in euthyroid patients with diabetes. Methods A total of 433 patients with type 1 or 2 diabetes were included in this retrospective cross-sectional study. Data included anthropometric measurements and biochemical parameters from diabetes clinic. Males with urine albumin creatinine ratio >2.5 and female’s >3.5 mg/mmoL were considered to have microalbuminuria. Results 34.9% of the patients had microalbuminuria. Prevalence of microalbuminuria increased according to TSH quartiles (26.9, 34.6, 38.5 and 44.9%, P for trend = 0.02). In a fully adjusted logistic regression model, higher TSH concentrations were associated with high prevalence of microalbuminuria (adjusted odds ratio 2.06 [95% CI: 1.14–3.72]; P = 0.02), while comparing the highest with the lowest quartile of TSH. Multiple linear regression analysis showed an independent association between serum TSH and urine albumin creatinine ratio (β = 0.007, t = 2.03 and P = 0.04). The risk of having microalbuminuria was higher with rise in TSH concentration in patients with younger age (<65 years), raised body mass index (≥25 kg/m2), hypertension, type 2 diabetes and hyperlipidaemia and age was the most important determinant (P for interaction = 0.02). Conclusion Serum TSH even in the euthyroid range was positively associated with microalbuminuria in euthyroid patients with diabetes independent of traditional risk factors. This relationship was strongest in patients with components of the metabolic syndrome

Maturation in serum thyroid function parameters over childhood and puberty:results of a longitudinal study

Context: Serum thyroid hormone levels differ between children and adults, but have not been studied longitudinally through childhood. Objective: To assess changes in thyroid-stimulating hormone (TSH) and thyroid hormone levels over childhood and their interrelationships. Design: Cohort study. Setting: The Avon Longitudinal Study of Parents and Children, a population-based birth cohort. Participants: A total of 4442 children who had thyroid function measured at age 7, and 1263 children who had thyroid function measured at age 15. Eight hundred eighty-four children had measurements at both ages. Main Outcome Measures: Reference ranges for TSH, free tri-iodothyronine (FT3), free thyroxine (FT4), their longitudinal stability, and interrelationships. Results: Children at age 7 years had a higher FT3 [6.17 pmol/L, standard deviation (SD) 0.62] than children at age 15 (5.83 pmol/L, SD 0.74); P , 0.0001 with 23.2% of children at age 7 having FT3 above the adult reference range. Higher FT3 levels at age 7 in boys (P = 0.0001) and girls (P = 0.04) were associated with attainment of a more advanced pubertal stage at age 13. TSH was positively associated with FT3 at age 7 and age 15 even after adjusting for confounders. In contrast, TSH was negatively associated with FT

Experimental investigation of foamy oil flow in solution gas-drive

Bibliography: p. 152-158Many pages are in colour

Geology and potentiality of basalts in Jabal Eghei area (Libya) : doctoral dissertation

Bazalti pokrivaju veći deo područja Jabal Eghei i deo su vulkanske provincije Tibesti. To su stratifikovani bazalti, izliveni preko proterozojskih metamorfita i granita i preko litološki različitih stena tercijarne starosti. Nastali tokom tri odvojene faze vulkanske aktivnosti u periodu između 12 i 8 Ma (I faza), 7- 4 Ma (II faza) i mlađe od 4 Ma (III faza). Osnovni minerali u bazaltima prema zastupljenosti su olivin, klinopiroksen i plagioklas, a od sporednih se javljaju minerali iz grupe spinela (magnetit ± ilmenit) i ostaci vulkanskog stakla. U bazaltima treće vulkanske faze utvrđeno je i prisustvo analcimiziranih leucita, analcima i renita, koji do sada nisu bili dokazani na ispitivanom području. Preovlađujuće strukture su porfirska i ofitska, a teksture masivna i vezikularna. Fizičko-mehanička svojstva bazalta su u očekivanim granicama, a sa geomehaničke tačke gledišta ispitivani bazalti su dosta homogeni. Iz rezultata tih proučavanja i ispitivanja metodom ultrazvuka, može se zaključiti da bazalti porfirske strukture i masivne teksture pokazuju najbolja svojstva sa aspekta kvaliteta kamena kao stenske mase. Bazaltni prah kao punilo testiran je sa aspekta mogućnosti pripreme kompozitnog materijala pogodnog za izlaganje kavitaciji, a rezultati pokazuju da hibridni kompozitni materijal koji se sastoji od bazaltnog praha i čestica glinice ima poboljšanu kavitacijsku otpornost u odnosu na čistu matricu i mikro kompozit koji se sastoji od bazaltnog praha i materijala matriksa. Ovaj materijal, pored toga, ima veoma dobra estetska svojstva i svojstva materijala otpornog na abraziju. Kod ocene potencijalnosti izdvojene su tri rudne formacije, koje obuhvataju bazalte sve tri vulkanske faze. Sa aspekta ukupne potencijalnosti područje Jabal Eghei predstavlja područje velike potencijalnosti za otkrivanje, istraživanje i definisanje budućih ležišta bazalta kao rudnih formacija velikog rasprostranjenja i dobrih kvalitativnih karakteristika, bilo da se radi o građevinskom kamenu, sirovini za bazaltna vlakna i kompozitne materijale.Basalts cover most of the Jabal Eghei area and are part of the Tibesti volcanic province. These are stratified basalts, covering Proterozoic metamorphites and granites and lithologically different rocks of Tertiary age. Basalts were formed during three separate phases of volcanic activity between 12 and 8 Ma (Phase I), 7- 4 Ma (Phase II) and less than 4 Ma (Phase III). The most abundant minerals in basalts are olivine, clinopyroxene and plagioclase, while the minor minerals are from the spinel group (magnetite ± ilmenite) and volcanic glass residues. In the basalts of the third volcanic phase, the presence of analcimitised leucite, analcime and rhoenite was detected, which has not been proven in the studied area so far. The predominant textures are porphyric and ophitic, while the structures are massive and vesicular. The physico-mechanical properties of basalt are within the expected limits, and from a geomechanical point of view, the tested basalts are quite homogeneous. From the results of these studies and tests by ultrasonic method, it can be concluded that the basalts of porphyric texture and massive structure exhibit the best properties in terms of stone quality as a rock mass. Basalt powder as a filler has been tested for the possibility of preparing a composite material suitable for cavitation exposure, and the results show that a hybrid composite material consisting of basalt powder and alumina particles has improved cavitation resistance over a pure matrix and a micro composite consisting of basalt powder and matrix material. This material has also very good aesthetic and abrasion-resistant properties. In the assessment of potentiality, three ore formations were identified, comprising basalts of all three volcanic phases. In terms of overall potential, the Jabal Eghei area is a high potential area for the discovery, exploration and definition of future basalt deposits as ore formations of large extent and of good qualitative characteristics, whether as building stone, basalt fiber raw materials and composite materials

Experimental and numerical assessment of the flexural response of banana fiber sandwich epoxy composite

Abstract Recently, most service or product-oriented industries have been focusing on their activities to uphold the green and sustainable environment protocol owing to the increased environmental pollution. Concerning this issue, industries are now concentrating on developing recyclable or waste materials products. This research advocates developing and validating a banana fiber sandwich composite to promote the beneficial usage of bio-waste. The composite sandwich specimens were fabricated with resin-impregnated woven banana fiber mat as a skin, and the core was reinforced with three different weight percentages (5, 7.5 and 10%) of chopped banana fiber. The sandwich specimens were pressed into a three-point bending test to validate the structural integrity. The flexural characteristics like flexural strength and modulus were examined experimentally, whereas the key strength indices like flexural stiffness and core shear modulus were evaluated analytically. Post-fracture surfaces were studied through a scanning electron microscope to investigate the failure mechanism. The experimental and analytical results indicate that 10% banana fiber content in the sandwich core increases the flexural strength and flexural modulus to 225% and 147%, respectively, compared to the neat epoxy core. The numerical simulation was also performed through FEA to validate the experimental findings. The numerical results are in good concurrence with the experimental one

Basalt-Polyester Hybrid Composite Materials for Demanding Wear Applications

Basalt as a filler in a polymer-based composite material fulfils the demand of being natural, environment-friendly material for the production of various composite materials. The material could be used as protective layer and the abrasion should be tested in order to evaluate the properties of the material. The cavitation test enables the evaluation of the possible service in conditions that simulate the extensive erosion. The presence of basalt in the matrix improves the resistance to cavitation. The possibility to further improve the material could be obtained using the reinforcement of the matrix itself by incorporation of submicron ceramic particles into the composite. The obtained hybrid composite material with the addition of reinforcement in the matrix further improves the cavitation resistance