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Muhanned Al-Rawi and Muaayed Al-Rawi

Abstract

This article deals with developing new modified algorithms of 40kb/s ADPCM. Beside the standard algorithm, three algorithms are developed to reduce the ADPCM distortion. The performances of all algorithms are evaluated with QAM signal at speed of 9.6kb/s. The outcomes demonstrate that the first proposed algorithm outperforms the other algorithms.

Open access

A. Enescu and E. Diaconu

Abstract

The concept of cogeneration defines the simultaneous production with the same installation of electric and thermal energy (in the form of hot water or steam). High-efficiency cogeneration implies that cogeneration production should ensure primary energy savings of at least 10% compared to the reference values of separate production of electricity and heat. This paper presents the process of functioning of a cogeneration plant, operating in the Suceava county, Romania, referring to the actual values regarding the consumption and the proportions of the raw material on the one hand and the energy produced on the other. It also describes the entire production process as well as the impact on the environment, the social and economic aspects of the implementation of such a project.

Open access

M.A. Păun, A.A. Doroftei, G.A. Tudor and I. Moldovan

Abstract

The CNC (Computer numerical control) is a machine that processes different kinds of materials at different types of precisions, determined by the system used to realize the transmission from the motor to the axes. In our project, we used the screw nut transmission because it offers a great precision and it has an optimal price-quality ratio.

Open access

F.G. Apostol and G. Predusca

Abstract

The project aims at creating a monitoring and control circuit in a desktop or complex system with the possibility to set the operating parameters. The project allows automatic and manual control of a certain number of fans using Pulse Width Modulation (PWM) control by the user or automatically by the system monitoring thresholds of minimum and average temperatures (also set by the user within the code). The system was designed with the following options: audible and visual alert when reaching maximum temperatures; time display, PWM percentage and three temperatures shown on a 16x2 LCD; the system-acquired data is then transmitted to a website. Additional features include the possibility of setting a color inside the system, also used as an alert as well as a color adjustment function by sound (for a musical lightshow). The mode of operation is based on the source code written in the Arduino IDE 1.6.3 software with the help of free libraries and free codes provided on the internet.

Open access

Nastase-Dan Ciobota and Gheorghe Gheorghe

Abstract

The paper aims to demonstrate the capability of FDM – Fused Deposition Modeling 3D printing technique to build complex structures designed for replacing anatomic parts of human body. It proposes to push the limits of FDM machine in order to achieve both structural integrity, mechanical properties and complexity of the 3D print part. Main applicability focus on bioengineering - developing new, lightweight implants but also can easily extended to airspace/automotive industry.

Open access

Wojciech Wiesner and Piotr Kunysz

Abstract

This article discusses issues related to safety during kitesurfing (swimming on a board with a kite). The considerations are based on risk management procedures. These procedures can be described interchangeably as managing your own safety. Risk management allows you to minimize threats without sacrificing your planned sport goals. The authors first describe the procedures related to the identification of threats occurring in this discipline. Teaching and practicing kitesurfing involves overcoming a large number of threats. These threats can have both external and internal character. The next stage is risk analysis, understood as the product of negative events and the probability of their occurrence. Afterwards, we discuss the ways of dealing with the threat in the event of its occurrence. The last stage is the risk control (tracking) - whether new threats have emerged, or the level of risk has remained unchanged. The described methodical impacts can be labelled as education for safety.

Open access

Zbigniew Talaśka and Bartłomiej Jakus

Abstract

This article presents the process of modernisation of a car lift in order to adjust it to the function of a hoist for lifting the decompression chamber cover in a breathing simulator used in the Department of Underwater Work Technology of the Naval Academy in Gdynia.

Open access

Daria Ługowska, Tomasz Ługowski, Olga Krzywińska, Mariusz Kozakiewicz and Paweł Grzelakowski

Abstract

Diabetes is an “epidemic of the 21st century” and it is estimated that in 2011 6.7% of Poland’s population suffered from diabetes, one quarter of which was unaware of the disease. Such a high prevalence of diabetes mellitus results in an increasing number of physicians being confronted with the problem of qualifying patient with diabetes to partake in amateur sports, including diving. This publication presents the most important information concerning risk assessment, admission of diabetic patients to amateur diving and some proposed protocols of management before and during sport practice.

Open access

Jerzy K. Garbacz, Ewa Kopkowska and Barbara Rymian

Abstract

The subsequent stages of the process of formulation of the equation for gas adsorption on a homogenous surface of a solid adsorbent were presented based on the general expression for the canonical ensemble of the mobile single-component adsorption monolayer. The method of formulating the configuration integral of the proposed model was discussed in detail where the role both of the attraction and repulsion between adsorbed molecules was emphasised. The expression for the probability of finding a molecule in a specified point on a surface of an adsorbent was modified by determining its magnitude by the adsorbent concentration. The expression for the so-called effective surface of the adsorbent was obtained by adapting a two-dimensional analogue equation of state hard spheres – Van der Waals equation (2D-vdW) and Reis-Frisch-Lebowitz equation accordingly (2D-RFL). As a result, two new adsorption equations were formulated which differ in detail concerning the adsorbate-adsorbate repulsion. On each of these equations theoretical analysis was performed in terms of two-dimensional phase transformation. In both cases it was proved that the proposed solution allows for the presence of two-phase transformations of the first type which is the gas-liquid condensation and solidification liquid-solid. The verification of the given approach was supplemented by the description of the experimental data given in reference literature and by obtaining a very good correlation between the theory and experiment.