2,177 research outputs found
Investigation into laser re-melting of inconel 625 HVOF coating blended with WC
High velocity oxy-fuel (HVOF) spraying of Diamalloy 1005 powders mixed with WC particles onto steel (304) is considered and laser re-melting of the resulting coatings is examined. Laser re-melting process is modeled to determine the melt layer thickness while temperature increase is formulated using the Fourier heating law. The morphological and metallurgical analyses prior and post laser re-melting process are carried out using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). X-ray diffraction (XRD) technique is used to determine the residual stress developed in the coating while the analytical formulation is adopted to predict the residual stress levels at the coating base material interface. The indentation tests are carried out to determine the Young’s modulus and fracture toughness of the coating prior to laser re-melting. Corrosion resistance of coating is measured using potentiodynamic polarization technique prior and post laser treatment process. The predictions of the melt layer thickness are in good agreement with experimental results. The presence of WC particles modifies temperature rise and its gradient in the coating while affecting the Young’s modulus, residual stress levels, and fracture toughness of the coating. The differences in the thermal properties of Inconel 625 powders and WC particles result in formation of small size cellular structure through polyphase solidification. WC dissolution in the central region of the large polycrystalline cells is observed due to the loss of carbon through carbonic gas formation. The results of corrosion tests prevail that significant improvement of corrosion resistance can be achieved after laser treatment process
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Fatty acid bioaccessibility and structural breakdown from in vitro digestion of almond particles.
Previous studies have shown that the size of almond particles influences lipid bioaccessibility during digestion. However, the extent of structural breakdown of almond particles during gastric digestion and its impact on lipid bioaccessibility is unclear. In this study, in vitro digestion of almond particles was conducted using a dynamic model (Human Gastric Simulator) and a static model (shaking water bath). Structural breakdown of particles during the gastric phase occurred only in the Human Gastric Simulator, as evidenced by a reduction in particle size (15.89 ± 0.68 mm2 to 12.19 ± 1.29 mm2, p < 0.05). Fatty acid bioaccessibility at the end of the gastric phase was greater in the Human Gastric Simulator than in the shaking water bath (6.55 ± 0.85% vs. 4.54 ± 0.36%, p < 0.01). Results showed that the in vitro model of digestion which included peristaltic contractions (Human Gastric Simulator) led to breakdown of almond particles during gastric digestion which increased fatty acid bioaccessibility
Recycling of mine wastes as raw materials for the construction sector: Solutions based on materials circularity and sustainable resource governance
The mining industry in general, and the phosphate industry in specific is an important mainstream in terms of waste rocks as it generates huge amounts of waste rocks and tailings during their activities. As a matter of example, the phosphate mining in Morocco produces amounts up to 150 million tons or even more of waste rocks and tailings each year. Non-polluting mine wastes (Tailings and waste rock) must be regarded as an opportunity to create new value. The reuse of these wastes, depending on their chemical, mineralogical and geotechnical properties, as alternative raw material in construction and building materials field constitutes a promising environmental solution. The main objective of our studies in Morocco was to investigate the feasibility of using non-polluting mine wastes to produce materials especially for the construction sector, such as using phosphate mine wastes as cementing materials, as additives in mortars or concrete, or as raw materials for bricks, ceramics and geopolymers or aggregates for roads construction and B25 concrete. The phosphate waste rock has to be classified in the category of natural aggregates that are similar to conventional materials. Laboratory and pilot scale investigations demonstrated that recycling mine wastes from may be feasible. The presentation will be focused mainly will be focused mainly on the valorization of phosphate waste rock an alternative aggregate in the construction sector. In addition, Jerada coal mine wastes recycling investigate the use of an integrated and circular approach based on coal recovery and waste rock recycling as alternative clays and aggregates (gravel and sand) in the construction sector. Froth flotation was used to recover coal particles using diesel as a collector and Methyl Isobutyl Carbinol as a frother. The tailings of coal flotation process (CFT) were used to manufacture fired bricks at a pilot scale. Then, gravel and sand obtained after a CMWR screening were tested as alternative materials for concrete production. The choice of the construction sector is based on its capacity to absorb huge quantity of materials
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Dietary Omega-3 Polyunsaturated Fatty Acid Deprivation Does Not Alter Seizure Thresholds but May Prevent the Anti-seizure Effects of Injected Docosahexaenoic Acid in Rats.
Background: Brain concentrations of omega-3 docosahexaenoic acid (DHA, 22:6n-3) have been reported to positively correlate with seizure thresholds in rodent seizure models. It is not known whether brain DHA depletion, achieved by chronic dietary omega-3 polyunsaturated fatty acid (PUFA) deficiency, lowers seizure thresholds in rats. Objective: The present study tested the hypothesis that lowering brain DHA concentration with chronic dietary n-3 PUFA deprivation in rats will reduce seizure thresholds, and that compared to injected oleic acid (OA), injected DHA will raise seizure thresholds in rats maintained on n-3 PUFA adequate and deficient diets. Methods: Rats (60 days old) were surgically implanted with electrodes in the amygdala, and subsequently randomized to the AIN-93G diet containing adequate levels of n-3 PUFA derived from soybean oil or an n-3 PUFA-deficient diet derived from coconut and safflower oil. The rats were maintained on the diets for 37 weeks. Afterdischarge seizure thresholds (ADTs) were measured every 4-6 weeks by electrically stimulating the amygdala. Between weeks 35 and 37, ADTs were assessed within 1 h of subcutaneous OA or DHA injection (600 mg/kg). Seizure thresholds were also measured in a parallel group of non-implanted rats subjected to the maximal pentylenetetrazol (PTZ, 110 mg/kg) seizure test. PUFA composition was measured in the pyriform-amygdala complex of another group of non-implanted rats sacrificed at 16 and 32 weeks. Results: Dietary n-3 PUFA deprivation did not significantly alter amygdaloid seizure thresholds or latency to PTZ-induced seizures. Acute injection of OA did not alter amygdaloid ADTs of rats on the n-3 PUFA adequate or deficient diets, whereas acute injection of DHA significantly increased amygdaloid ADTs in rats on the n-3 PUFA adequate control diet as compared to rats on the n-3 PUFA deficient diet (P < 0.05). Pyriform-amygdala DHA percent composition did not significantly differ between the groups, while n-6 docosapentaenoic acid, a marker of n-3 PUFA deficiency, was significantly increased by 2.9-fold at 32 weeks. Conclusion: Chronic dietary n-3 PUFA deficiency does not alter seizure thresholds in rats, but may prevent the anti-seizure effects of DHA
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A single meal has the potential to alter brain oxylipin content.
Our objective was to determine whether consumption of a single meal has the potential to alter brain oxylipin content. We examined the cerebrum of mice fed a single high-fat/high-sucrose Western meal or a low-fat/low-sucrose control meal, as well as fasted mice. We found no changes in fatty acid composition of cerebrum across the groups. The cerebral oxylipin profile of mice fed a Western meal is distinct from the profile of mice fed a low-fat/low-sucrose meal. Cerebral gene expression of cyclooxygenase 1, cyclooxygenase 2, and epoxide hydrolase 1 were elevated in Western meal-fed mice compared to low-fat/low-sucrose meal-fed mice. Mice that consumed either meal had lower gene expression of cytochrome P450, family 2, subfamily j, polypeptide 12 than fasted mice. Our data in this hypothesis-generating study indicates that the composition of a single meal has the potential to alter brain oxylipins and the gene expression of the enzymes responsible for their production
Estimation of TNF- α and LDH in Chronic Periodontitis Patients in Mosul
The objective of the study is to estimate salivary concentration of TNF-α and LDH level in chronic periodontitis and control group, and correlate them with periodontal parameters. The study group consisted of 44 patients suffering from chronic periodontitis, aging between ≤16-45 years old and 40 control samples collected from healthy individuals ranged between 16-40 years old .Chronic periodontitis was assessed on the basis of several periodontal parameters, including probing pocket depth (PPD), clinical attachment loss (CAL), bleeding on probing (BOP) and plaque index (PI). 5ml of unstimulated saliva was collected from patients and control groups to measure salivary biomarkers by ELISA technique. the mean concentrations of TNF-α in the study and control groups were (6.9pg/ml) and (5.6 pg/ml) respectively, data analysis showed no significant difference between the two groups (P< 0.05), and the mean LDH level in chronic periodontitis was (7.7855) and in control group the mean was (0.5555) and the difference was highly significant )p≤ 0.000). Salivary TNF-α and LDH showed positive correlation with clinical periodontal parameters
Some Technological Properties of Sawn Board Eucalyptus Camaldulensis Denh.Grown In Askikalak
This study deals with wood density and static bending boards property of Eucalyptus camaldulensis Den. It was conducted using standardized, defect-free test specimens. Boards of air drying showed lowest value (749.117 kg/cm²) of static bending when compared with kiln (812.267kg/cm²) and solar (815.267kg/cm²) drying respectively, whereas, the quarter sawing boards recorded the lowest rates (586.633kg/cm²) when compared with flat sawn boards (1008.467kg/cm²), Also 2cm thickness level achieved the lowest rate (747.367kg/cm²) when compared with other two levels 4cm (812.650 kg/cm²) and 6cm (837.633kg/cm²) of thickness. But, there were no any significant effects of wood density on the studied factors. E. camaldulensis in Kurdistan Region of Iraq has potential for traditional uses and by itself it can be harvested by applying suitable techniques at plantation areas, in saw mills and drying for utilization
Ligamentum flavum cyst in the lumbar spine: a case report and review of the literature
Degenerative changes in the lumbar spine can be followed by cystic changes. Most reported intraspinal cysts are ganglion or synovial cysts. Ligamentum flavum pseudocyst, as a cystic lesion in the lumbar spine, is a rare and unusual cause of neurologic signs and symptoms and is usually seen in elderly persons (due to degenerative changes). They are preferentially located in the lower lumbar region, while cervical localization is rare. Complete removal of the cyst leads to excellent results and seems to preclude recurrence. We report the case of a right-sided ligamentum flavum cyst occurring at L3–L4 level in a 70-year-old woman, which was surgically removed with excellent postoperative results and complete resolution of symptoms. In addition, we discuss and review reports in the literature
Variation in morphology and branching pattern of superior mesenteric artery
The anatomical variations of superior mesenteric artery branches are common. In this study we reported an extraordinary morphology and branching of superior mesenteric artery, during our routine dissection of a 38-year-old Sudanese male cadaver, where the superior mesenteric artery forms an arch over the confluence of inferior vena cava and left renal vein.
Other variations observed were: 1) The superior mesenteric artery shares the same origin of coeliac trunk; 2) The unusual origin of right hepatic artery.
We think that the knowledge of these variations plays an important role in conducting and planning of radiological and surgical procedures especially in hepatobiliary and pancreatic surgery. Morphology and branching patterns of this artery is anecdotic, which makes this case the most unique
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