Investigation of low- and high cycle fatigue in Al 2024-T4 alloy

The article presents the results of low-(LCF) and high (HCF) fatigue in samples of aluminum alloy 2024-T4, which is used in aircraft construction, mainly for highly loaded structural components, including for plating and fuselage frames and girders rotor blades of helicopters. This alloy is used where it is required a high strength to weight ratio of the product and high resistance to fatigue. Moreover, it is poorly weldable and has a low corrosion resistance. The tests were performed on hourglass and cylindrical samples, with a parallel and perpendicular orientation relative to the "direction of embodiment" or blank sheet rolling direction. Material for the study was collected from the production line design elements PZL-130 Orlik TC-II. There have been a description of the analytical results in the form of Manson-Coffin and Morrow equations.

Sheet thinning prediction method based on localized friction effect in deep-drawing

The paper investigated the effect of localized friction on sheet thinning under lubricated conditions in the deep-drawing process. The Finite Element Analysis (FEA) was used to evaluate the sheet thinning of the AISI 304 sheet under six segmented blank-sheet interfaces. Different values of variable coefficient of friction (VCOF) in each segmented area were investigated, and the sheet thickness values at the considered areas were measured. The regression analysis models (Linear Regression, Response Surface Method, and Polynomial Regression) was used to determine the relationships between VCOF and sheet thinning. The results showed that the Linear Regression showed the best fit. The significant factor analysis was also carried out to determine how the localized friction affected the sheet thinning. The contributions of VCOF from at least two segmented areas affected the sheet thinning at any particular location. The obtained relationships of the VCOF and sheet thinning could be beneficial for the localized friction control for highly complex shapes.

Pattern of Different Types of Fingerprints amongst the Community- an Observational Cross Sectional Study

Background: No two people have exactly the same fingerprints. Even identical twins, with identical DNA, have different fingerprints. This uniqueness allows fingerprints to be used in all sort of ways, including background checks, biometric security, mass disaster identification, and of course, in criminal situations. This scientific examination of fingerprints for identification purposes is known as dactylography. Aim: To prove the uniqueness and study various pattern of fingerprint in an individual. Objectives: 1) To study pattern of fingerprints for identification of an individual, 2) To study different types of fingerprints and keep statistical data of loops, whorls, arches and compound/composite in a group of individual, and 3) To study different methods of fingerprinting in an individual. Methodology: The study was conducted among individuals under the age group of 25-40 years, including 50 males and 50 females. The study was conducted based on Henry Galton method. The fingerprints were taken by means of an ink pad on a blank sheet; a magnifying glass was used for clarity of the finger impressions. Result: There are 4 types of fingerprints namely loops-52.16%, whorls-34.99%, composite-10.04% and arches-2.81%. Conclusion: On this basis uniqueness of fingerprints was proved. Fingerprints are considered as secondary evidence in the court of law, even though it is used as a primary and the most basic source of identification of an individual. Also according to our study the percentage of types of fingerprints varied.

Planning and providing mental health services for a community

The fundamental building blocks of modern mental health services (primary care provision, inpatient wards, and some form of multi-disciplinary community team) are broadly established in high-income countries. In low- and middle-income countries, the availability of each of these three components is highly variable and investment often reflects local traditions and practices. Planning rarely begins with a blank sheet, and while it should be informed by local needs assessment and epidemiology, it is likely to be an exercise in the possible. Strengthening primary care provision and establishing multi-disciplinary teams that can provide outreach to the most severely ill are key to success. Organizational simplicity and stability, coupled with effective liaison with social care, mark effective systems.

Starting with a Blank Sheet

Determining principles of war and the mental effort required to articulate them are important for military officers. During a crisis when time is short and there are many demands on our attention, we must simplify and extract general rules from conflicting data points. Principles of War have been espoused for centuries, but the urge to codify such rules took on added impetus in the twentieth century. Today, such principles are considered invaluable learning tools at military schools. Yet, it is time for an update, because those used today were devised a century ago by a soldier who had little or no insight into warfare at sea or in the air. His precepts have survived, largely intact, until the present day. The result has been a distorted view of war. We must begin anew—not to reshape the earlier principles, but to look at modern war and devise new ones that govern the new environment.

Redrawing Operation a Star Shape from Cylindrical Shape Using Experimental and FE Analysis

The aim of this paper is to design and fabricate a star die and a cylindrical die to produce a star shape by redrawing the cylindrical shape and comparing it to the conventional method of producing a star cup drawn from the circular blank sheet using experimental (EXP) and finite element simulation (FES). The redrawing and drawing process was done to produce a star cup with the dimension of (41.5 × 34.69mm), and (30 mm). The finite element model is performed via mechanical APDL ANSYS18.0 to modulate the redrawing and drawing operation. The results of finite element analysis were compared with the experimental results and it is found that the maximum punch force (39.12KN) recorded with the production of a star shape drawn from the circular blank sheet when comparing the punch force (32.33 KN) recorded when redrawing the cylindrical shape into a star shape. This is due to the exposure of the cup produced drawn from the blank to the highest tensile stress. The highest value of the effective stress (709MPa) and effective strain (0.751) recorded with the star shape drawn from a circular blank sheet. The maximum value of lamination (8.707%) is recorded at the cup curling (the concave area) with the first method compared to the maximum value of lamination (5.822%) recorded at the cup curling (the concave area) with the second method because of this exposure to the highest concentration of stresses. The best distribution of thickness, strains, and stresses when producing a star shape by

Handwriting in children with Attention Deficient Hyperactive Disorder: role of graphology

Background Handwriting difficulties are common in children with attention deficient hyperactive disorder (ADHD). The aim of our study was to find distinctive characteristics of handwriting in children with ADHD by using graphology to analyze physical characteristics and patterns, and to evaluate whether graphological analysis is an effective ADHD diagnostic tool for clinicians. Method The cohort included 49 children aged 13–18 years attending a tertiary neurology and epilepsy center in 2016–2017; 22 had a previous DSM-IV/V diagnosis of ADHD. The children were asked to write a 10–12-line story in Hebrew on a blank sheet of paper with a blue pen over a 20-min period. The samples were analyzed by a licensed graphologist blinded to the clinical details of the children against a predetermined handwriting profile of individuals with ADHD. Each ADHD characteristic identified in each sample was accorded 1 point, up to a total of 15 points. Patients with a graphology score of 9–15 were considered to have ADHD. Results There were 21 boys (43%) and 28 girls (57%) in the cohort; 15 boys (71.4%) and 7 girls (25%) had a DSM-IV/V diagnosis of ADHD. The mean graphology score was significantly higher in the children who had a DSM-IV/V diagnosis of ADHD than in the children who did not (9.61 + 3.49 vs. 5.79 + 4.01, p = 0.002, respectfully). Using a score of 9 as the cutoff, in the girls, graphology had a specificity of 80% (95% CI 59.2–92.8) and a of sensitivity 71.4% for predicting ADHD. Corresponding values in the boys were 75.0 and 76.2%. Conclusion The handwriting of children with ADHD has specific characteristics. Graphology may serve as a clinically useful tool in the diagnosis of ADHD.

A NEW TYPE OF INCREMENTAL BENDING METHOD FOR COMPLICATED CURVED SHEET METAL

A new type of incremental bending process for complicated curved sheet metal is proposed in the paper. The blank sheet is bended incrementally step by step. To validate the forming process, an incremental bending prototype is designed and manufactured, which was composed of a 3-DOF working table, a flexible supporting system and a 3D scanning system. The forming trajectory based on the theory of the minimum energy is planned according to the designed model of the sheet metal. Several experiments are carried out and the designed part is manufactured, which validated the proposed incremental forming method was successful.

Closing the Loop: Integrating 3D Printing with Engineering Design Graphics for Large Class Sizes

Closing the loop by completing all stages in the design process is an important experience for every engineer. There is significant experiential merit, for example, in providing first year students with a design challenge that starts with a blank sheet of paper and ends with reflective observation of their fabricated model. The advent of 3D printing has “game changer” potential as a vehicle for this experience, but it has limitations, especially for large class sizes.An activity was devised to complete the design loop using 3D printing. This initiative effectively overcame the limited throughput rates and high material costs associated with 3D printing for 427 students.Activity outcomes were assessed via an exit survey, including whether students perceived differences between their CAD and 3D physical models. Students enjoyed the experience, and grew from it. The outcomes from this initiative along with the lessons learned may be of use to other instructors considering a similar experiential path.