153 research outputs found

    Bioethanol Production from Lignocellulosic Biomass

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    An overview of the basic technology to produce bioethanol from lignocellulosic biomass is presented in this context. The conventional process includes two main steps. First, lignocellulose must be pretreated in order to remove lignin and enhance the penetration of hydrolysis agents without chemically destruction of cellulose and hemicellulose. Second, the pretreated material is converted to bioethanol by hydrolysis and fermentation. Some typical published studies and popular processing methods in attempts to improve the biomass conversion to bioethanol and increase the cost-effectiveness are also introduced briefly. Herein, the refinery of the resulted raw bioethanol mixture to obtain higher concentrated solution is not regarded

    Preparation and characterization of magnesium hydroxyapatite coatings on 316L stainless steel

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    Magnesium hydroxyapatite coatings (MgHAp) were deposited on the surface of 316L stainless steel (316L SS) substrates by electrodeposition technique. Different concentrations of Mg2+ ion were incorporated into the apatite structure by adding Mg(NO3)2 into electrolyte solution containing 3×10-2 M Ca(NO3)2, 1.8×10-2 M NH4H2PO4 and   6×10-2 M NaNO3. With Mg2+ concentration 1×10-3 M, the obtained coatings have 0.2 wt% Mg2+. The influences of scanning potential ranges, scanning times to deposit MgHAp coatings were researched. The analytical results FTIR, SEM, X-ray, EDX, thickness and adhension strength showed that MgHAp coatings were single phase of HAp, fibrous shapes, thickness 8.1 µm and adhesion strength 7.20 MPa at the scanning potential ranges of 0÷-1.7 V/SCE and scanning times of 5 scans. Keywords. 316L SS, Electrodeposition, MgHAp

    ELECTRODEPOSITION OF CO-DOPED HYDROXYAPATITE COATING ON 316L STAINLESS STEEL

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    Hydroxyapatite (HAp) co-doped by magnesium (Mg), strontium (Sr), sodium (Na) and fluorine (F) were deposited on the 316L stainless steel (316L SS) substrate by electrodeposition method. The influences of scanning potential ranges, scanning times, scanning rates to form MgSrFNaHAp coating were investigated. The analytical results FTIR, SEM, Xray, EDX, thickness and adhension of the obtained coating at scanning potential ranges of 0 ÷ -1.7 V/SCE; scaning times of 5, scanning rate of 5 mV/s showed that MgSrFNaHAp coatings were single phase crystals of HAp, rod shape with the thickness 8.9 µm and the adhesion strength reached 8.38 MPa

    Ho Chi Minh's Thoughts On Control Of The State's Power And Lessons For Vietnam

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    In Vietnam, the State’s power is unified, agencies shall assign, coordinate and control each other in the exercises of the legislative, executive, and judicial powers. This is necessary to prevent abuse of power and ensure the state’s power. The Constitution 1946 was written by Ho Chi Minh (1890 -1969) and created a mechanism and foundation to control the state’s power in Vietnam. Nearly, in the Constitution 2013, the issue of controlling state power is recorded. The assignment and control are reflected in the assignment of the scope of power to each state agency. From the approach of philosophical, social philosophy, and political philosophy, through research and analysis documents in Ho Chi Minh Complete Collection; of previous researchers and policies, legal of Vietnam’s Government on control of the state's power and lessons for Vietnam today. The result shows that Ho Chi Minh’s thought on controlling power has shown the basic contents related to asserting that the power owner belongs to the people and focusing on supervision; use the Constitution to limit state power. The article also gives experiences when studying Ho Chi Minh's thoughts on state power control over Vietnam today

    Novel products of reaction between K[PtCl3(eugenol)] and some pyridine’s derivatives

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    The interaction between K[PtCl3(Eug)] (M0) and either 4-carboxylpyridine (4-Cpy) or 4-methylpyridine (4-MePy) has been studied for the first time. The structures of unusual resulting complexes, namely [PtCl(Eug-1H)(4-CPy)] (M1), trans-[PtCl2(4-MePy)2] (M2), trans-[PtCl2(Eug)(4-MePy)] (M3) were determined by means of platinum analysis, IR, 1H NMR spectroscopy and single-crystal X-ray diffraction. In these complexes, the amines coordinate with Pt(II) via the N atom and eugenol (Eug) in M1, M3 coordinates with Pt(II) via ethylenic double bond of the allyl group. In M1, the deprotonated eugenol is bound up with Pt(II) not only at the C=Callyl but also at C atom of the benzene ring to generate the metallacyclic complex. M2 and M3 possess trans configuration. Keywords. Eugenol, platinum(II) complex, 4-carboxylpyridine, 4-methylpyridine

    A Giant Frontal Meningioma with Psychiatric Symptoms in a Young Woman: A Case Report

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    Background:Frontal meningioma is often asymptomatic but patients might experience psychiatric symptoms. Since symptoms are atypical in giant meningioma, to the best of our knowledge, we present a rare clinical scenario. Case Presentation: A 24-year old female patient with no medical history presented with two months of depressive symptoms, personality changes such as easy irritability, and feelings of frustration and mental depression, as well as forgetfulness and blurred vision. Brain magnetic resonance imaging (MRI) revealed a well-defined markedly enhancing lesion in the left frontal region measuring 65 x 70 x 70 mm with mass effects to the adjacent brain tissue and associated surrounding edema which was pressed to the frontal horn of the lateral ventricle. The patient underwent frontal unilateral craniotomy and excision of the tumor. After surgery, the quality of life was improved. Conclusion: Meningioma with psychiatric symptoms is quite rare. This clinical case helps clinicians avoid missing symptoms and use appropriate management strategies for patients with giant meningiomas

    Spondylolysis-induced Multilevel Lumbar Spondylolisthesis; Challenges in Lumbar Spine Surgery

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    Lumbar spondylolysis and multilevel lumbar spondylolysis account for 4.4-5.8% and 0.3% of the general population, and multilevel lumbar spondylolysis resulting in spondylolisthesis is even rarer. Herein, we report two cases of three-level lumbar spondylolisthesis because of spondylolysis: A 49-year-old woman was admitted to the hospital for dull lower back pain over the past 8 months, with exacerbating symptoms when standing and walking. Spasticity at lumbar region and radiculopathy at S1 nerve root was found on examination and a 63-year-old man was admitted to the hospital because of numbness and perianal sensory disturbances with difficulty urinating 2 weeks ago, the symptoms gradually increased to the time of examination. Both patients were diagnosed with multilevel lumbar spondylolisthesis because of spondylolysis and were indicated for posterior lumbar interbody fusion (PLIF). After surgery, both patients recovered well without any significant complications. The improved treatment results suggest the application of PLIF technique to treat spondylolysis-induced multilevel lumbar spondylolisthesis

    Electrodeposition of HAp coatings on Ti6Al4V alloy and its electrochemical behavior in simulated body fluid solution

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    Hydroxyapatite (HAp) coatings were prepared on Ti6Al4V substrate by electrodeposition method from electrolyte solution containing Ca(NO3)2, NH4H2PO4 and NaNO3. The results show that the HAp coatings were single phase crystals of HAp. Scanning electron microscope (SEM) images present that HAp/Ti6Al4V have flake shapes which arrange to form like-coral agglomerates. In vitro test of the Ti6Al4V and HAp/Ti6Al4V in simulated body fluid (SBF) solution was investigated with different immersion times. pH of SBF solution decreased and the mass of materials increased. SEM images prove the formation of apatite on the surface of Ti6Al4V and HAp/Ti6Al4V. The corrosion current density during immersion time of substrate is always higher than the one of HAp/Ti6Al4V because the deposited HAp can protect well for the substrate

    Determinants of organic food purchasing intention: an empirical study of local consumers in Da Nang city, Central Vietnam

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    With the rapid economic development in the past decades, Vietnamese people are more and more aware of the role of safe food for their health and that of their families. Currently, the trend of organic food consumption is happening faster, especially in urban areas. The study aims to determine the influence of transparent information and knowledge about organic products on consumers' attitudes, trust, and subjective norms affecting their purchase intention of organic products. Data were collected from 420 consumers in Da Nang city, Central Vietnam. Exploratory Factor Analysis (EFA) method and Structural Equation Modeling (SEM) were used to evaluate the scale's reliability and identify the impact factors. The results show that attitudes and trust have a positive relationship with the intention to buy organic food. In addition, research shows that trust is a predecessor of attitudes and mediates the relationship between information, knowledge about organic food, and intention to buy organic food. The study's findings are consistent with previous literature and provide implications for food managers, organic food businesses, and the community
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