Hydrogen adsorption configurations on Ge(001) probed with STM

The adsorption of hydrogen on Ge(001) has been studied with scanning tunneling microscopy at 77 K. For low doses (100 L) a variety of adsorption structures has been found. We have found two different atomic configurations for the Ge-Ge-H hemihydride and a third configuration that is most likely induced by the dissociative adsorption of molecular hydrogen. The Ge-Ge-H hemihydride is either buckled antiparallel or parallel to the neighboring Ge-Ge dimers. The latter configuration has recently been predicted by M. W. Radny et al. [J. Chem. Phys. 128, 244707 (2008)], but not observed experimentally yet. Due to the presence of phasons some dimer rows appear highly dynamic

THE INFLUENCE OF THE APPLICATION OF COMMUNICATIVE APPROACH ON THE DEVELOPMENT OF STUDENTS’ ENGLISH VOCABULARY AT THE EIGHTH GRADE OF MTs NEGERI KARANGKENDAL - CIREBON

SAEDI ALFIANTO: THE INFLUENCE OF THE APPLICATION OF COMMUNICATIVE APPROACH ON THE DEVELOPMENT OF STUDENTS’ ENGLISH VOCABULARY AT THE EIGHTH GRADE OF MTs NEGERI KARANGKENDAL. Language is very important. People in the world use language to communicate to each other. They have used language since he born until pass away. They express their thought and their idea using language. So, using language they do cooperation each other on work. In teaching and learning process method or approach is very important, There are a lot of methods or approaches. One of them is the communicative approach. By using communicative approach students can understand the subject matter. They are like grammar, speaking, vocabulary, etc. The aim of this research is to know the influence of the communicative approach on the development of students’ English vocabulary. The method of this research is quantitative. The techniques for collecting data in this research are observation, interview, test, and questionnaire. Then, the writer uses the statistical analysis that is product moment by Pearson. The writer got the result of students response of questionnaire of application of communicative approach is 80.4, the score considered good response. The result of pre test is 47.6 and post test is 69.5. From the score, the students’ development is increase 27.1 point. The influence of development of students’ English vocabulary (rxy) is 0.63 and (rt) is 0.32. The score show that it is significant influence, because (rxy) bigger than (rt). The application of communicative approach influence 39.6% of the development of students’ English vocabulary. After collecting and analyze the data, the writer concludes that the application of communicative approach (X variable) has significant influence on the development of students’ English vocabulary (Y variable). One of the successes of teaching and learning is using the various approach or method of teaching to manage the class more comfortable and enjoyable. So the students get much knowledge

Shape Memory Behavior of Dense and Porous NiTi Alloys Fabricated by Selective Laser Melting

Selective Laser Melting (SLM) of Additive Manufacturing is an attractive fabrication method that employs CAD data to selectively melt the metal powder layer by layer via a laser beam and produce a 3D part. This method not only opens a new window in overcoming traditional NiTi fabrication problems but also for producing porous or complex shaped structures. The combination of SLM fabrication advantages with the unique properties of NiTi alloys, such as shape memory effect, superelasticity, high ductility, work output, corrosion, biocompatibility, etc. makes SLM NiTi alloys extremely promising for numerous applications. The SLM process parameters such as laser power, scanning speed, spacing, and strategy used during the fabrication are determinant factors in composition, microstructural features and functional properties of the SLM NiTi alloy. Therefore, a comprehensive and systematic study has been conducted over Ni50.8 Ti49.2 (at%) alloy to understand the influence of each parameter individually. It was found that a sharp [001] texture is formed as a result of SLM fabrication which leads to improvements in the superelastic response of the alloy. It was perceived that transformation temperatures, microstructure, hardness, the intensity of formed texture and the correlated thermo-mechanical response are changed substantially with alteration of each parameter. The provided knowledge will allow choosing optimized parameters for tailoring the functional features of SLM fabricated NiTi alloys. Without going through any heat treatments, 5.77% superelasticity with more than 95% recovery ratio was obtained in as-fabricated condition only with the selection of right process parameters. Additionally, thermal treatments can be utilized to form precipitates in Ni-rich SLM NiTi alloys fabricated by low energy density. Precipitation could significantly alter the matrix composition, transformation temperatures and strain, critical stress for transformation, and shape memory response of the alloy. Therefore, a systematic aging study has been performed to reveal the effects of aging time and temperature. It was found that although SLM fabricated samples show lower strength than the initial ingot, heat treatments can be employed to make significant improvements in shape memory response of SLM NiTi. Up to 5.5% superelastic response and perfect shape memory effect at stress levels up to 500 MPa was observed in solutionized Ni-rich SLM NiTi after 18h aging at 350ºC. For practical application, transformation temperatures were even adjusted without solution annealing and superelastic response of 5.5% was achieved at room temperature for 600C-1.5hr aged Ni-rich SLM NiTi. The effect of porosity on strength and cyclic response of porous SLM Ni50.1 Ti49.9 (at%) were investigated for potential bone implant applications. It is shown that mechanical properties of samples such as elastic modulus, yield strength, and ductility of samples are highly porosity level and pore structure dependent. It is shown that it is feasible to decrease Young’s modulus of the SLM NiTi up to 86% by adding porosity to reduce the mismatch with that of a bone and still retain the shape memory response of SLM fabricated NiTi. The shape memory effect, as well as superelastic response of porous SLM Ni50.8Ti49.2,were also investigated at body temperature. 32 and 45% porous samples with similar behaviors, recovered 3.5% of 4% deformation at first cycle. The stabilized superelastic response was obtained after clicking experiments

Preparation and assessment of prostaglandin E2 formulated with hydroxypropyl methyl cellulose and span 60 sustained release pessaries (vaginal suppositories)

Prostaglandin E2 (PGE2) is presented as a composed release pessaries utilizing two-polymer base. Hydroxypropyl methyl cellulose HPMC was used as a viscosity modifier and bioadhesive agent. Furthermore, nonionic surfactant span 60 (Sp 60) with or without cholesterol (CH) mixed with the base was used. The defined pessaries were assessed with regards to hardness, weight variation, softening time test and in vitro release studies. Every one of the formulations demonstrated consistency with pharmacopoeial benchmarks. In vitro expressed PGE2 disintegration was completed in phosphate buffer pH 4.5 utilizing USP XXII basket apparatus. TEM demonstrated that the PEG/Sp 60 bases formed niosomal vesicles upon hydration with water while the WH15/Sp 60 gave rise to emulsions when melted in phosphate buffer pH 4.5. Both types of the novel composed release pessaries (WH15/Sp 60 and WH15/HPMC) indicated moderate release rates for PGE2 when no CH detected and the recipes WH15/30%HPMC and PEGIII/SP60 being used as an effective matrix previously to give PGE2 sorting out the release. The outcomes also demonstrated that the CH addition to either WH15 or PEG base brought about increased PGE2 release rates. No interaction amongst PGE2 and excipients were observed from DSC studies.               KEY WORDS: Pessary, PGE2, WH15, HMPC, Sp 60, Polymer, Sustained release, TEM Bull. Chem. Soc. Ethiop. 2018, 32(2), 361-370.DOI: https://dx.doi.org/10.4314/bcse.v32i2.1

Altered Pulmonary Venous Flow Pattern in Young Adults with Atrial Septal Defect

Introduction: Atrial septal defect (ASD) is a common congenital heart disease and causes left-to-right shunting and significant right ventricular (RV) volume overload. The goal of this study was to evaluate the influence of these hemodynamic changes on pulmonary venous flow pattern in young adults.Methods: Complete echocardiographic examination was performed in a group of 40 young adults (aged < 40 years) who had secundum type ASD and was compared to 40 age-matched individuals in control group who had no cardiac abnormality. Systolic and diastolic flow velocities in pulmonary veins (PV), superior vena cava (SVC), inferior vena cava (IVC) and RV functional parameters were recorded and evaluated.Results: As opposed to healthy young individuals who showed distinct S and D waves with diastolic predominance in pulmonary vein Doppler, in patients with ASD a continuous flow with increased systolic peak that began in systole and continued to the late diastole was observed. The RV systolic function increased compared to the control group.Conclusions: In patients with ASD, the pattern of pulmonary veins flow transforms into a single continuous antegrade wave with systolic dominance due to persistent shunting of left atrial blood in to right heart chambers as well as increased RV pump function on pulmonary vein (by means of ASD), SVC and IVC, and could be used as a screening method for the presence of secundum type ASDs in young adults

THE INFLUENCE OF THE APPLICATION OF COMMUNICATIVE APPROACH ON THE DEVELOPMENT OF STUDENTS’ ENGLISH VOCABULARY AT THE EIGHTH GRADE OF MTs NEGERI KARANGKENDAL - CIREBON

SAEDI ALFIANTO: THE INFLUENCE OF THE APPLICATION OF COMMUNICATIVE APPROACH ON THE DEVELOPMENT OF STUDENTS’ ENGLISH VOCABULARY AT THE EIGHTH GRADE OF MTs NEGERI KARANGKENDAL. Language is very important. People in the world use language to communicate to each other. They have used language since he born until pass away. They express their thought and their idea using language. So, using language they do cooperation each other on work. In teaching and learning process method or approach is very important, There are a lot of methods or approaches. One of them is the communicative approach. By using communicative approach students can understand the subject matter. They are like grammar, speaking, vocabulary, etc. The aim of this research is to know the influence of the communicative approach on the development of students’ English vocabulary. The method of this research is quantitative. The techniques for collecting data in this research are observation, interview, test, and questionnaire. Then, the writer uses the statistical analysis that is product moment by Pearson. The writer got the result of students response of questionnaire of application of communicative approach is 80.4, the score considered good response. The result of pre test is 47.6 and post test is 69.5. From the score, the students’ development is increase 27.1 point. The influence of development of students’ English vocabulary (rxy) is 0.63 and (rt) is 0.32. The score show that it is significant influence, because (rxy) bigger than (rt). The application of communicative approach influence 39.6% of the development of students’ English vocabulary. After collecting and analyze the data, the writer concludes that the application of communicative approach (X variable) has significant influence on the development of students’ English vocabulary (Y variable). One of the successes of teaching and learning is using the various approach or method of teaching to manage the class more comfortable and enjoyable. So the students get much knowledge

Using Microwave Irradiation for synthesis of Imides consist of Pyromellitimide

Bispyromellitimides are an important class of substrates in polymer chemistry as monomers in polyimides or their copolymers synthesis.A fast and efficient microwave-assisted synthetic procedure for the preparation of series of these compounds 3(a-h) from the reaction of pyromellitic anhydride and aniline or its derivatives (a-h) is described. Elemental analysis, FT-IR and1H-FT-NMR Spectra revealed the confirmation of these compounds in good agreement