Friction anisotropy at Ni(100)/(100) interfaces: Molecular dynamics studies

The friction of surfaces moving relative to each other must derive from the atomic interaction at interfaces. However, recent experiments bring into question the fundamental understanding of this phenomenon. The analytic theories predict that most perfect clean incommensurate interfaces would produce no static friction, whereas commensurate aligned surfaces would have very high friction. In contrast recent experiments show that the static friction coefficient between clean but 45° misoriented Ni(001) surfaces is only a factor of 4 smaller than for the aligned surfaces (θ∼0°) and clearly does not vanish (θ is defined as the rotation angle between the relative crystallographic orientations of two parallel surfaces). To understand this friction anisotropy and the difference between analytic theory and experiment, we carried out a series of nonequilibrium molecular dynamics simulations at 300 K for sliding of Ni(001)/Ni(001) interfaces under a constant shear force. Our molecular dynamics calculations on interfaces with the top layer roughed (and rms roughness of 0.8 Å) lead to the static frictional coefficients in good agreement with the corresponding experimental data. On the other hand, perfect smooth surfaces (rms roughness of 0 Å) lead to a factor of 34–330 decreasing of static friction coefficients for misaligned surfaces, a result more consistent with the analytic theories. This shows that the major source of the discrepancy is that small amounts of roughness dramatically increase the friction on incommensurate surfaces, so that misaligned directions are comparable to aligned directions

Dentistry and psychology in the care and treatment of odontophobic patients: the concise systematic review

This study aimed to demonstrate the use of psychological methods in the routine care of a dental office. The research was carried out through a literature review in the PubMed, Scielo, Cochrane Library, Web of Science and Scopus, and Google Scholar databases, from 2002 to 2021. Throughout the work, the causes and symptoms of anxiety of these patients during the care process and the view of the dentist was also described in terms of crises of fear and often refusal of treatment by these patients. At the end of the study of the works described above, the great importance of the interdisciplinary work of Psychology and Dentistry as a method of optimizing the care of odontophobic patients was concluded

Gene Expression Analysis Methods on Microarray Data a A Review

In recent years a new type of experiments are changing the way that biologists and other specialists analyze many problems. These are called high throughput experiments and the main difference with those that were performed some years ago is mainly in the quantity of the data obtained from them. Thanks to the technology known generically as microarrays, it is possible to study nowadays in a single experiment the behavior of all the genes of an organism under different conditions. The data generated by these experiments may consist from thousands to millions of variables and they pose many challenges to the scientists who have to analyze them. Many of these are of statistical nature and will be the center of this review. There are many types of microarrays which have been developed to answer different biological questions and some of them will be explained later. For the sake of simplicity we start with the most well known ones: expression microarrays

Student Law Office Conference: A Platform for Student Engagement with Clinical Legal Education?

I was one of a group of students from Northumbria University who organised the first student conference on clinical legal education on Saturday 4th December 2004. This short article is intended to explain why we thought such a conference was necessary and whether it was worthwhile

KECERDASAN SPASIAL SEBAGAI PENUNJANG PENGEMBANGAN KREATIVITAS MAHASISWA DESAIN GRAFIS DALAM PEMBELAJARAN NIRMANA

AbstractNirmana plays an important role on how to organize and prepare the basicelements of a design. By studying Nirmana, students are expected to have anunderstanding, skills, and sensitivity regarding the governance of designelements in forming a harmonious and balanced composition. Sensitivity togovernance of design elements is closely related to spatial intelligence, theability to visualize ideas with regard to space and place. Spatial intelligence is anintelligence possessed by most graphic design student. Spatial intelligence needto be sharpened by the students so that they can understand the meaning andessence of Nirmana (Visual Literacy) subject, so the learning objectives can beachieved. To sharpen students' spatial intelligence, the spatial intelligenceteaching strategy is needed. This paper describes the spatial intelligenceteaching strategy which can be applied to Nirmana (Visual Literacy) subject.The study in this paper uses a qualitative approach, aimed to explore the role ofspatial intelligence teaching strategy to the process of development of creativityof students in learning the Nirmana (Visual Literacy). The analysis process isdone through the collection of data that is measurable. AbstrakNirmana memegang peranan penting tentang bagaimana menata dan menyusun elemen dasar sebuah desain. Dengan mempelajari nirmana,mahasiswa diharapkan dapat memiliki pemahaman, keterampilan, dankepekaan mengenai tatakelola unsur-unsur desain dalam membentuk komposisi yang serasi dan seimbang. Kepekaan terhadap tatakelola unsur-unsur desain tersebut berkaitan erat dengan kecerdasan spasial, yaitu kemampuan memvisualisasi ide-ide yang berkenaan dengan ruang dan tempat. Kecerdasan spasial merupakan kecerdasan yang dimiliki oleh sebagian besar mahasiswa desain grafis. Kecerdasan spasial perlu diasah oleh mahasiswa agar mereka dapat memahamimakna dan esensi mata kuliah nirmana, sehingga tujuan pembelajaran nirmana dapat tercapai dengan baik. Untuk mengasah kecerdasanspasial mahasiswa dibutuhkan strategi pengajaran kecerdasan spasial.Tulisan ini menjelasakan tentang strategi-strategi pengajarankecerdasan spasial yang dapat diterapkan pada mata kuliah nirmana.Studi dalam tulisan ini menggunakan pendekatan kualitatif, bertujuanuntuk mengeksplorasi peran strategi pengajaran kecerdasan spasialterhadap proses pengembangan kreativitas mahasiswa dalampembelajaran nirmana. Proses analisis dilakukan melalui pengumpulandata yang bersifat terukur

Impact of educational intervention regarding hazards of obesity and its preventive measures among students of commerce colleges of Ahmedabad city, Gujarat, India

Background: The prevalence of obesity has increased worldwide in almost every country in all the age groups. A college is a key location for educating students about health, hygiene and nutrition, and for putting in place interventions to promote the health of them. Objective of the study was to know the prevalence of obesity and overweight among students of commerce colleges of Ahmedabad city and to assess knowledge of these students regarding hazards of obesity and its preventive measures before and after educational interventional training.Methods: The present interventional study was undertaken during September 2011 to December 2011 in randomly selected 3 commerce colleges of Ahmedabad city, Gujarat. Total 627 students between the age group of 18 to 23 years were examined after taking written informed consent of their parents using pre-designed, pre-tested, semi-structured proforma. Anthropometric measurements were taken and BMI were calculated. The prevalence of overweight and obesity were determined based on the IOTF (International Obesity Task Force) criteria. Single educational training for 45 minutes was given to the students and their post-intervention knowledge for same was assessed after the training. Thus collected data was analyzed using SPSS 17 (Trial version).Results: Overall, the total number of obese adults identified in whole study population was 64 (10.2%) and numbers of overweight adults were 65 (10.3%). Baseline knowledge of the students regarding hazards of obesity like hypertension, cancer, heart attack and diabetes mellitus was 19.7%, 16.1%, 16.5% and 24.5% respectively which was significantly increased to 93.6%, 94.5%, 96.0% and 94.1% respectively after the intervention. Baseline knowledge of the students regarding preventive measure of obesity like avoiding junk food/ healthy diet, exercise and meditation was 23.6%, 24.4% and 25.9% respectively which was significantly increased to 95.3%, 96.9 and 97.4% respectively after the intervention.Conclusions: There was significant improvement in the knowledge regarding hazards of obesity and its preventive measures among college students after our single educational session

Heat and Mass Transfer in Wood Composite Panels During Hot-Pressing: Part I. A Physical-Mathematical Model

A theoretical model for heat and moisture transfer in wood composite mats during hot-pressing is developed based on the basic principles of mass conservation, momentum of gas flow, energy conservation, and resin curing kinetics. The model provides a mathematical description of the coupled physical phenomenon in hot-pressing process as a closure problem in which fifteen governing equations are rigorously derived to solve fifteen unknown variables of mat environmental conditions. These variables, including mat temperature, gas pressure, and moisture content are linked to basic material properties such as mat density, thermal conductivity, and permeability. Initial and boundary conditions for solving the governing equations are also discussed

A Review on Attacks in Mobile Ad hoc Network (MANET)

MANET (Mobile Ad hoc Network) is a wireless network having no any fixed infrastructure. It consists of autonomous, self-organized wireless mobile nodes, which are to move in or out in the network. MANET performs all the network activities such as message delivery, discovery of route path etc. using its nodes only. It uses the routing protocols such as DSDV, DSR and AODV etc. As there is no clear line of defense in MANET, so, it is more prone to both the legitimate users and the malicious nodes . The presence of these malicious nodes is one of the major the challenges in MANET and it has become necessary to design a very robust solution for the security of MANET. MANET is more vulnerable to attacks because of its openness, dynamic and infrastructure-less nature. The two types of routing attacks are , such as active i.e. Gray Hole Attack, Black Hole Attack, Flooding, Spoofing, Wormhole and passive i.e. Eavesdropping, Traffic Analysis. AODV is used to discover the path from source to destination but its more prone to malicious intent like gray hole and black hole attacks. Gray Hole attack tends to drop the packet while the routing process. In Black Hole attack, the malicious node presents itself as the shortest and newest route to the destination node and attracts the routing packets. This paper presents a focus on the fundamental issues in MANET by describing its related research in the previous year along with its concept, features and vulnerabilities