213 research outputs found
Students’ Recognition of Function Transformations’ Themes Associated with the Algebraic Representation
The topic of function transformations is a difficult mathematical topic for school and college students. On the other hand, GeoGebra is a new technological tool for mathematics teaching and learning, so we wanted to experiment with this new tool in teaching non-basic function transformations to middle school students. Specifically, we wanted to examine how students conceive function transformations after working with GeoGebra, when this conceiving relates to the algebraic representation. The research participants were 19 ninth grade high achieving students who learned, with the help of GeoGebra translations, reflection and stretch. During their learning, the participants worked with transformations on the absolute function, the cubic function, and the quartic function. After they finished the transformation unit, the participants solved mathematics problems by means of function transformations. This research is interested in the participants’ solution of problems that included two non-basic functions: the absolute value of the quadratic function and the rationale function. The research findings show that the participants were generally able to solve successfully mathematical problems, by means of transformations on new and non-basic functions. Furthermore, the participants encountered difficulties in working with translations. These difficulties were due to the special algebraic form of the functions. We recommend that mathematics teachers expose middle school students to transformations on different types of non-basic function during learning this mathematical topic. Future researches could examine the impact of activities that include such functions and that are GeoGebra based on students’ conceptions and behavior when performing translations is involved
Corrosion Protection Study of Carbon Steel and 316 Stainless Steel Alloys Coated by Nanoparticles
The Corrosion protection effectiveness of Alimina(Al2O3,50nm)and Zinc oxide (ZnO,30nm) nanoparticales were studied on carbon steel and 316 stainless steel alloys in saline water (3.5%NaCl)at four temperatures: (20,30,40,50 OC)using three electrodes potentiostat. An average corrosion protection efficiencies of 65 %and 80% was achieved using Al2O3 NP's on carbon steel and stainless steel samples respectively, and it seems that no effect of rising temperature on the performances of the coated layers. While ZnO NP'S showed protection efficiency around 65% for the two alloys and little effected by temperature rising on the performanes of the coated layers. The morphology of the coated spesiemses was examined by Atomic force microscope
Protection of Galvanized steel from corrosion in salt media using sulfur nanoparticles
تم دراسة خصائص الكبريت النانوي بوساطة جهاز مجهر القوة الذري. أظهرت قياسات مجهر القوة الذرية الحجم الكلي للكبريت النانوي المحضر بوساطة مزج ثايوسلفات الصوديوم مع مستخلص نبات اليقطين مساويا 93.62نانومتر .تم دراسة حماية التاكل لمعدن الكلفانك ستيل في الوسط الملحي وبمختلف درجات الحرارة بوساطة الكبريت النانوي وتم الحصول على افضل نتائج ثرموديناميكية للمعدن بوجود الكبريت النانوي حيث كفاءة التثبيط ومقاومة لتاكل للمعدن تعطي اعلى قيمة عند اعلى درجة حرارية بوجود المثبط بلمقارنة بغيابة .كذلك سرعة التاكل تقل عند زيادة درجة الحرارة بوجود الكبريت النانوي, القيم الموجة للدالة الحرارية بوجود وبعدم وجود الكبريت النانوي تدل على انه التفاعل ماص للحرارة . لذا يقترح ان الكبريت النانوي مثبط جيد لمعدن الكالفانك ستيل في الوسط الملحي The characteristics of sulfur nanoparticles were studied by using atomic force microscope (AFM) analysis. The atomic force microscope (AFM) measurements showed that the average size of sulfur nanoparticles synthesized using thiosulfate sodium solution through the extract of cucurbita pepo extra was 93.62 nm. Protecting galvanized steel from corrosion in salt media was achieved by using sulfur nanoparticles in different temperatures. The obtained data of thermodynamic in the presence of sulfur nanoparticles referred to high value as compares to counterpart in the absence of sulfur nanoparticles, the high inhibition efficiency (%IE) and corrosion resistance were at high temperature, the corrosion rate or weight loss decreased with increasing temperature in the presence of sulfur nanoparticles. The positive value of enthalpy ∆H* for galvanized steel with and without sulfur nanoparticles indicates that the reaction was endothermic. Therefore, the sulfur nanoparticles can be suggested as good inhibitor for galvanization in salt media
EFFECT OF AMIODARONE ON RABBITS' OPTIC NERVE AND THE AMELIORATIVE EFFECT OF VITAMIN E: FTIR STUDY
Objective: The study aimed to investigate the structural and conformational changes induced by short-term administration of the amiodarone in the optic nerve besides validating whether vitamin E coadministration with amiodarone will improve these changes.
Methods: Thirty New Zealand white rabbits from both sexes were haphazardly categorized into three groups, whereas each group contains ten rabbits (20 eyes). One of these groups served as a control that received an intraperitoneal injection of normal saline. Rabbits in the second group intraperitoneally (ip) injected daily with 160 mg/kg body weight (bw) of amiodarone for two weeks. The last group orally administration 100 mg/kg bw of vitamin E with the 160 mg/kg bw of amiodarone ip daily for two weeks until the time of sacrifice. Fourier transform infrared spectroscopy (FTIR) analysis was conducted on the optic nerve of the all groups.
Results: The results obtained from the FTIR spectrum revealed that the short-term administration of amiodarone caused a significant alteration in the stretching NH-OH region. A newly detected component centered at 3739±1 cm-1 was assigned as strO-H. There was a significant decrease (p˂0.05) in the bandwidth and band position of one component of strO-H that centered at 3598±1 cm-1. Moreover, remaining vibrational bands (O-Hasym and O-Hsym) were shifted to higher frequencies. Coadministration of vitamin E with amiodarone reduced the contour to four components as a control with significant increase in the band position of O-Hasym and the bandwidth of one component of str O-H. Amiodarone administrations lead to reducing the area ratio of asymCH2 to symCH2 and elevation of the area ratio of asymCH2 to asymCH3 while the coadministration of vitamin E returned it as the control ratio. The percentage of the β-turn was significantly increased while the α-helix content was decreased due to amiodarone. The contents of both components were considered mimicking the control values when Vitamin E was co-administered with amiodarone.
Conclusion: The study stated that amiodarone could change the solubility and folding of the optic nerve proteins. Finally, vitamin E intake with amiodarone turns many of these changes induced by amiodarone to normal levels, which make it a good supplement for amiodarone users
A Study of Adiponectin in Children with Diabetes Mellitus
Objectives: Adiponectin is a hormone produced by adipose tissue. It is secreted exclusively by adipocytes and appears to play a role in the pathophysiology of obesity, diabetes mellitus (DM), and its comorbidities. The aim of this study was to assess adiponectin levels in diabetic children with type 1 DM (T1DM) and type 2 DM (T2DM), and to detect its prognostic role in them. Methods: This study was undertaken from April to July 2011 at Minia University Children’s Hospital, Egypt, and included 314 children aged 2–18 years divided into two patient groups. Group I consisted of 164 pre-diagnosed diabetic patients, further subdivided into Group Ia which included 142 patients with T1DM and Group Ib, 22 patients with T2DM; Group 2 included 150 apparently healthy children as a controls; they were age- and sex-matched to the diseased group. Patients were subjected to a thorough history taking, clinical examination, and laboratory investigations including assessment of HbA1c percentages, fasting C-peptide levels, lipid profiles and fasting serum adiponectin levels. Results: Adiponectin levels did not differ significantly between patients with T1DM and T2DM, but it was significantly higher in diabetic patients than in the controls. In T1DM, adiponectin had positive significant correlations with the duration of the disease and waist circumference, while in T2DM, it had a positive significant correlation with the dose of insulin given and negative significant associations with diastolic blood pressure, cholesterol, and C-peptide levels. Conclusion: The results of the study suggest that adiponectin can play a protective role against the metabolic complications of DM
The Frequency of Type 2 Diabetes Mellitus among Diabetic Children in El Minia Governorate, Egypt
Objectives: Type 2 diabetes mellitus (T2DM) in children and adolescents is becoming an increasingly important public health concern throughout the world. This study aimed to estimate the frequency of T2DM among diabetic young people in El-Minia Governorate, Egypt, and to detect its risk factors. Methods: A total of 210 diabetic patients under 18 years old in Minia Governorate were included in the study and underwent a thorough history-taking, a physical examination and laboratory investigations. Results: T2DM was present in 28 patients (13.3%); it was significantly present in 18 females (64.3%) and 20 (71.4%) of them had a positive family history of DM. T2DM patients had significantly higher BMI and waist circumference centiles for age and sex than those with T1DM. Also, haemoglobin A1c %, serum C-peptide and cholesterol levels were significantly higher in T2DM than T1DM patients. Finally, there were weak significant positive correlations between C-peptide level and both BMI and waist circumference. Conclusion: T2DM is no longer a disease of adults but can also occur in children and adolescents. The results suggested that obesity, female gender and a positive family history of DM are risk factors for T2DM. Also, patients with T2DM had poorer glycaemic control and hypercholesterolemia than those with other types of diabetes
Structural and optical properties Investigation of ZnxCd1-xS thin films
CdZnXS1-X thin films with different composition have been deposited on glass substrate by by the spray pyrolysis method at RT using CdCl2 (0.1M),ZnCl2(0.1M)and H2NCSNH2(0.1M)solution and a substrate temperature of ( 400±20°C). X-ray diffraction studies reveal that the films are polycrystalline in nature with hexagonal structure and preferential orientation along (002) . The grain size of the films is found to increase form (37.397 to 46.902) nm with increasing Zinc concentration while the strain and the dislocation density of the films are found to decrease from (7.15 to 4.54) 10 4 rad and from (3.82 to 1.93) 10 14 lines.m-2 respectively . The transmittance spectrums of CdZnxS1-x thin films reveal very pronounced interference effects for photon energies below the fundamental absorption edge by exhibiting interference pattern . The optical energy gap for CdZnxS1-x thin films increases and shifts towards the UV region as the Zn concentration in the films increased .Â
A Study Of Corrosion Behavior Of Low Carbon Steel In Acidic And Basic Washing Water Of Crude Oil Solution At Different Temperatures
The corrosion behavior of low carbon steel in washing water of crude oil solution has been studied potentiostatically at five temperatures in the range ( 303 –343 )K, at pH ( 4 ) and at pH (4,6,7,9,11 ) at (343K)..The corrosion potential shifted to more negative values with increasing temperature and the corrosion current density increased with increasing temperature, the corrosion current density (icorr) decreased with increasing pH in the rang ( 4 – 7 ) and it increased with increasing pH in the rang ( 9 – 11 ) at ( 343 K ), while the corrosion potential generally variation with increasing pH in the rang (4-11)at(343K. From the general results for this study can be seen that thermodynamic and kinetic function were also calculated (?G, ?S, ?H and Ea
A Study Of Corrosion Inhibition Of Low Carbon Steel In Washing Water Of Crude Oil Solution In The Presence Of Folic Acid
The corrosion behavior of low carbon steel in washing water of crude oil solution has been studied potentiostatically at five temperatures in the range (30–70)°C .The corrosion potential shifted to more negative values with increasing temperature and the corrosion current density increased with increasing temperature. Folic acid had on inhibiting effect on the corrosion of low carbon steel in washing water at a concentration (5× 10-4-- 5× 10-3 ) mol/dm3 over the temperature range (30–70)°C. Values of the protection efficiency were calculated from the corrosion current density .From the general results for this study, it can be seen that thermodynamic and kinetic function were also calculated (?G, ?S, ?H and Ea ) to comparison these values in presence and absence of inhibitor (folic acid )
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