Physical Sciences and Engineering

Study on residual stress characteristics of vertical welded joints

With the acceleration of industrial process, the requirement of welding quality becomes higher, especially the residual stress. For vertical welded joints, a weld model is constructed in this paper, which includes four layers on the inside and outside. Eight different welding sequences are arranged and combined. Based on the finite element method of thermo-mechanical coupling, the variation rules of residual stress in vertical and horizontal directions are calculated. The results show that the maximum residual stress in the weld is distributed in the superheated zone, not in the weld zone.

Tuning of pid controller for buck converteusing modified bacterial foraging algorithm

DC-DC converter is used to stabilize or control the DC output voltage. Many optimization techniques have been developed to turn the PID parameters. In this paper, deals with the Modified Bacterial Foraging based Optimization technique for DC–DC Buck converter. MBF algorithm is proposed new method for PID controller optimization to improve the dynamic performance of the voltage regulator. The result of simulation shows MBF- PID controller provide better performance of the Buck converter than the conventional PID controller.

Study on friction characteristics between seal ring and cylinder

Friction characteristics between seal ring and cylinder in pneumatic balancer have great significance to the optimization and upgrading of the working state. The variation law of lubricating grease film thickness and contact stress in space is solved by MATLAB. The results show that the dynamic load of pneumatic balancer has little effect on the friction characteristics of cylinders in the main contact area, and the relative motion speed can be increased. The method of rheological index can increase the thickness of lubricating grease film.

Ventilatory function response to training of cervical muscles in mechanical neck pain: a randomized controlled study

Background: Neck pain is a common musculoskeletal complaint with tremendous impact on health and quality of life. Neck pain also leads to pulmonary function restrictive disorder. Aim: This study aimed to investigate the effect of deep cervical muscle training using pressure biofeedback device on ventilatory functions in patients with chronic mechanical neck pain. Subjects: Forty subjects of both sexes with mean age 24.8± 1.87 years were participated in this study.

Influences of methods of desamerization on the nutritional value of boscia senegalensis seeds of Niger

Immature seeds of Boscia senegalensis (Anza in Hausa language) used in human nutrition, undergo several treatments to remove bitterness. This study is to analyse the influence of removing bitterness on the nutritional value of these seeds. Seeds from 14 treatment methods are levied century in two department: Banibangou (Tillaberi) and Bambeye (Tahoua region). For the 14 methods, the contents of macronutrients (Fats and proteins contents) (fats and proteinaceous material), micronutrients (P, B, K, Ca, Mg, Mn, Cu, Zn, Fe and Na), in phytic acid as well as antioxidant activity are determined.

Data mınıng and text mınıng wıth bıg data: revıew of dıfferences

In recent years, organizations have come across complex databases due to the development of technology, the growth of databases and information technologies, and the use of widespread information technologies. If the data found in line with the needs of the institutions are managed successfully and effectively, it is obvious that the institutions and organizations will offer great advantages and opportunities in economic terms. Each action performed in the digital environment leaves a data record behind it.

Public debt and investment growth, evidence from Egypt

In this paper we are trying to investigate the impact of public debt accumulation on the Egyptian public investment growth to ascertain the validity of crowding out theory. The research adopts Vector Error Correction Estimation techniques to determine the terrible nature of the relationship between public debt accumulation (both internal and external debt) and public investment growth in Egypt. We are using data covering the period 1981-2015 sourced from the Central Bank of Egypt and the World Bank data base.

Cryolipolysis versus liposuction in abdominal adiposity in females

Purpose: The current study was conducted to compare between the effects of cryolipolysis and liposuction in abdominal adiposity in females. Subjects and Methods: Thirty females suffering from localized fat deposits at the abdominal area were involved in the study. Their Body Mass Index(BMI) between 30 kg\m2 -34.9 kg\m2.Participants age was ranged from 30-40 years. They were classified randomly and equally into two groups Group I: This group was composed of fifteen female suffering from localized fat deposits at the abdominal area.

Vibrational characterization of in-situ stair performance using energy-harvester data

Vibration performance and energy harvesting potential of two in-situ stairs is evaluated using voltage output of an electromagnetic induction harvester prototype. First, the validation and benchmarking procedure is provided for a prototype electromagnetic induction harvester to assess 1) performance as a quantitative sensor for vibrations and 2) feasibility as a low-demand energy harvester. Secondly, the dynamic characteristics of two in-situ stairs are evaluated and compared to FEA and simplified analytical single-degree of freedom (SDOF) models.