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  • Open access
  • 81 Reads
Decomposition of Bromocresol Green Using Non-Thermal Atmospheric Pressure Plasma Jet

This research study aims to decompose bromocresol green (C21H14Br4O5S) using direct irradiation of non-thermal atmospheric pressure plasma jet. The absorbance spectra of the bromocresol green solution have been measured as well as its electrical conductivity and also its pH before and after different time durations of irradiation. The results showed that the lengths of conjugated systems in the molecular structure of bromocresol green decreased, and the bromocresol green solution was decolorized as a result of the decomposition of bromocresol green. This result indicates that cold atmospheric pressure plasma jet irradiation is capable of decomposing and can also be used for water purification.

  • Open access
  • 86 Reads
Non-destructive evaluation of internal sulphate attack in cement-based materials applying non-linear ultrasonic techniques
Published: 09 November 2020 by MDPI in The 1st International Electronic Conference on Applied Sciences session Materials

One of the most aggressive attacks to which cement-based materials can be exposed is that produced by sulphate. During this attack expansive products are formed, causing volumetric strains in hardened materials, which brings microcracking and the reduction of their strength and durability.

The use of non-destructive techniques for characterizing the microstructure and service properties of cement-based materials has become an important research field. Particularly, they can also be useful for following the development of deleterious processes which can affect those materials. Among them, non-linear ultrasonic (NLU) techniques have shown to be useful for evaluating the material degradation. In recent studies, they have been used for detecting cracks due to steel corrosion in concrete structures. NLU technique is based on the fact that the non-linear interaction of ultrasound with cracked materials generates higher acoustic harmonics.

The aim of this work is to study the possibility of using the NLU technique for the non-destructive evaluation of damage in cement-based materials due to sulphate attack. Cement pastes were prepared using ordinary Portland cement to which an appropriate amount of calcium sulphate 2-hydrate was added during the setting for producing an internal attack in the samples. Furthermore, its effects have been followed with mercury intrusion porosimetry, scanning electron microscopy, linear ultrasonic technique, X-ray diffraction and X-ray fluorescence. The expansion and the mechanical strengths of the samples were also determined. The preliminary results indicate that the NLU technique could be useful for studying the development of sulphate attack, complementing the information provided by other techniques.

  • Open access
  • 107 Reads
Synteza kompozytów polimerowych o właściwościach luminescencyjnych

This study presents the synthesis and properties of new polymeric materials in form of composites with photoluminescent filler. As a main monomer a bisphenol A glycerolate (1 glycerol/phenol) diacrylate (BPA.DA) was used. In order to obtain the appropriate viscosity of the polymerization system, three active diluents (methyl methacrylate, N-vinyl-2-pyrrolidone and 2-hydroxyethyl methacrylate) were applied. In role of photoluminescent dopant the copolymer of N-vinyl-2-pyrrolidone with 2,7-(2-hydroxy-3-methacrylo-yloxypropoxy)naphthalene, in form of powder was adopted. The compositions were prepared with an increasing amount of filler: 0, 0.5, 1, 2, 5, 10% w/w. After polymerization reaction, samples which generating of green-yellow light by excited by UV radiation were obtained. The influence of the increasing luminescent filler content on the selected properties of the composites was evaluated. The thermal and mechanical behaviors of composites were determined by means of differential scanning calorimetry (DSC), and Shore D hardness. Moreover the chemical structure of polymeric materials were confirmed by the attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FT-IR) method. These results shown that the incorporation of the photoluminescent filler into structure of compositions can be interesting method of synthesis e.g. stable and functional polymeric coatings or optical fiber sensors.

  • Open access
  • 67 Reads
Effect of soil loading/unloading on its acoustic behavior

The aim of the study was to understand the changes of p-wave velocity and acoustic emission (AE) as a result of soil loading/unloading. The soil was dune sand (poorly graded - SP index and three its fractions as follows: 2.36-0.6 mm, 0.6-0.3mm and 0.3-0.075 mm). The dried sand samples were studied using odometer instrument with simultaneous measurement of load and stain level. The stress range was 0-15 kPa.

Each sample was loaded and unloaded while measuring primary wave speed and AE activity (number of hits) at each loading/unloading stage. The resonance frequency of ultrasonic sensors was 75 kHz, while measurement of AE was restricted by digital filtering in the range 300-500 kHz to avoid the effect of ultrasonic wave excitation on the AE signal.

The experimental results show that the increase of stress level causes the rise of p-wave speed in the range of 514-630, 490-624, 521-637, 476-563 m/s for natural dune sand of 2.36-0.6, 0.6-0.3, 0.3-0.075 mm fractions, respectively. Note that the coarser the sand particle size, the more intense the non-linear response to sand unloading. Analysis of the wave velocity vs. the change in deformation shows a gradual increase in the p-wave velocity value with increasing deformation, as well as a sharp decrease with relaxation of deformation (unloading branch).

The analysis of AE behavior indicates gradual increase of the AE activity with increase of stress and strain levels for all studied samples, while a minor AE activity during samples unloading is also observed.

Finally, one can see the difference in the behavior of the two elastic parameters. In the stress increase branch: gradual increase in p-wave speed and sharp excitation of AE activity. In the stress relaxation branch: abrupt decrease in p-wave speed and minor excitation of AE signals.

  • Open access
  • 118 Reads
Multi-parameters approach for damage propagation analysis in Fiber Reinforced Polymer Composites

The use of Carbon Fiber Reinforced Polymers (CFRP) has tremendously increased in the last decades due to their exceptional combination of reduced density and high mechanical strength, that makes them ideal in many advanced structural applications. Assessing damage evolution in CFRP is a very important task being, at the same time, very complicated due to the complex mechanical response of the composites. The acoustic emission technique (AE) is a non-destructive technique based on the recording of sound waves generated inside the material as a consequence of the presence of active defects. Proper analysis of the recorded waves can be used for monitoring damage evolution in many materials including composites. The acoustic track associated with the entire loading history of the sample or the structures is usually followed by using some descriptors such as the amplitude of the sound waves, the number of counts and so on. In this paper the acoustic emission in CFRP single lap shear joints will be monitored by using a multi-parameter approach based on the contemporary analysis of multiple features such as ASL, Initiation Frequency, Reverberation Frequency and so on to understand if a proper combination of them can be adopted for a more robust description of damage propagation in CFRP structures

  • Open access
  • 90 Reads
Numerical Evaluation of Protein Global Vibrations at Terahertz Frequencies by means of Elastic Lattice Models

Proteins represent one of the most important building blocks for most biological processes. Their biological mechanisms have been found to correlate significantly with their dynamics that is commonly investigated through Molecular Dynamics (MD) simulations. However, important insights on protein dynamics and biological mechanisms have also been obtained via much simpler and computationally efficient calculations based on Elastic Lattice Models (ELMs). Despite their simplification with respect to MD frameworks, the application of Structural Mechanics approaches, such as modal analysis, to the protein ELMs has allowed to find impressive results in terms of protein dynamics and vibrations. The low-frequency vibrations extracted from the protein ELM are usually found to occur within the Terahertz (THz) frequency range and correlate fairly accurately with the observed functional motions. In this contribution, the global vibrations of lysozyme will be investigated by means of a Finite Element (FE) truss model and we will show that there exists complete consistency between the proposed FE approach and one of the more well-known ELMs for protein dynamics, the Anisotropic Network Model (ANM). The proposed truss model can consequently be seen as a simple method, easily accessible to the Structural Mechanics community members, to analyze protein vibrations and their connections with the biological activity.

  • Open access
  • 99 Reads
Qualitative and quantitative characterisation of minor chemical elements in Diesel Particulate Matter by Laser Induced Breakdown Spectroscopy
Published: 09 November 2020 by MDPI in The 1st International Electronic Conference on Applied Sciences session Energy

In this research we investigate the minor chemical elements contained in the Diesel particulate matter (DPM) exhaust emissions, generated by in - use Diesel engine passenger vehicles. For this purpose we apply a high resolution optical emission spectroscopy technique, for precise spectrochemical analysis of Diesel particulate matter. By means of the Laser Induced Breakdown Spectroscopy (LIBS) analytical method we quantify detected minor chemical elements in DPM. Particulate matter samples were obtained from in-use Diesel engine passenger vehicles of diverse types and models from major brand car producers in Europe. We analysed particulate matter, extracted from the exhaust manifold part, from different passenger vehicles, that are used in daily life environment. The LIBS results have revealed the presence of minor chemical elements: Silicon, Nickel, Titan, Potassium, Strontium and Molybdenum.

  • Open access
  • 326 Reads
Sustainable exploitation of by-products of vitivinicultural origin in winemaking

Grapes are cultivated globally with the total area under vines reaching 7.4 million hectares in 2018 and the global wine market is expected to increase to USD 423 billion by the end of 2023. However, winemaking produces large quantities of by-products/wastes like grape pomace (GP; the residue of pressed grapes), wine lees (WL; the residue accumulating in vessels containing wine after fermentation) and vine shoots (VS; generated during the pruning season in the vineyard). Exploitation of agro-industrial side-streams, wastes and residues, such as WL, GP and VS, is an issue of vital importance to global, good environmental governance. As WL and GP constitute valuable sources of nutrients and VS source of cellulose fibers, their use for novel products with applications in winemaking is of major importance. In the present study the recent trends in sustainable exploitation of such by-products for application in winemaking are presented. WL consists mainly of ethanol, tartaric acid and yeast cells and it is usually used for the recovery of these bioactive compounds and as a nutrient supplement of lactic acid bacteria and yeasts growth. GP has been used for the recovery of phenolic compounds, as a substrate for alcohol production and as fertilizer in the vineyard. New trends include its use for eliminating unwanted wine compounds (like ocratoxin A and pesticides) and as a sustainable fining agent of wines (in order to modify its sensory features such as astringency, bitterness, and mouthfeel). Finally VS has been used as biochar and for nanocomposite film production.

  • Open access
  • 68 Reads
Research and Development of A Low Cost Smart Cardio Pulmonary Resuscitation (CPR) Device Using Locally Available Raw Material for Cardiac Arrest Patients

Cardiovascular disease is the main worldwide reason for death, representing 17.3 million deaths for each year, a number that is expected to cross more than 23.6 million by 2030. In 2008, cardiovascular deaths accounted for 30 percent of every single worldwide demise, with 80 percent of those passing occurring in low and middle income nations. Cardiovascular diseases can cause the heart beat to stop. Somebody can quit breathing as well as have heart failure from heart attack, strokes (when the blood stream to a piece of the brain abruptly stops),choking on something, close suffocating occurrences (when somebody is submerged for a really long time and stops breathing),a terrible neck, head, or back damage, extreme electrical stuns (like from touching a power line),being exceptionally wiped out from a genuine disease, an excessive amount of dying, serious unfavorably susceptible responses and gulping a medication or synthetic. Cardiopulmonary resuscitation (CPR) is a lifesaving medical procedure that is mainly applied to cardiac arrest victims. Keeping in mind the end goal to restart the heart, the well known technique is CPR. If a person suffers from cardiac arrests than immediate treatment like CPR with chest compressions and artificial ventilation along with defibrillation is very likely to vastly improve the patient’s chance of survival. Traditionally CPR is performed manually. Manual CPR is performed by applying external chest compressions followed by artificial ventilation. It helps to pump blood around the person's body when their heart can’t. To carry out CPR a person presses up and down on the casualty’s chest (chest compressions) and gives them a series of rescue breaths to help save their life when they are in cardiac arrest. Problems we face in performing manual CPR are that we're not focusing on training the people who most need to be trained. Also in Bangladesh most of our ambulance personnel don’t have the professional experience to provide CPR. The technique most commonly taught is something that the vast majority cannot perform for ten minutes. Many of the people who will be called upon to perform CPR weigh too little to perform 2" chest compression on a chest of average stiffness. Manual CPR is sometime not possible to continue perfectly. In abroad there are automated CPR device but they are very expensive as like from USD 15000 to USD 20000. This paper design and discuss a low cost cardio pulmonary resuscitation (CPR) device using locally available raw material for cardiac arrest patients. This CPR is automated, portable and it has multi functional features. This is very cost effective product and people can easily afford to buy it. The unit price of this CPR is USD 500. In our country ambulance can have this device as well as hospitals. This device is very user friendly and anyone with basic educational knowledge can operate it. It will increase the life expectancy of the patients of cardiovascular disease.

  • Open access
  • 97 Reads
Development of Wireless Monitoring System for Pulse Rate: A New Approach

Pulse is the rate at which someone’s heart beats. Pulse rate is usually called your heart rate, which is the number of times heart beats per minute (bpm). Nowadays, people affected by suffering from cardiac diseases are increasing day by day. So here an urge arises to design a compatible system that would give us the accurate and quick pulse rate readings. Various types of heart diseases including cardiac arrhythmia, myocardial infraction, and coronary artery disease are one of the main reasons behind the causes of death around the world. It can be mitigated if we know the pulse rate and monitor it properly. But constant monitoring can be expensive for private sector and so we are proposing to solve the problem the implementation of wireless network based on Bluetooth. The pulse rate data is sent from Arduino Uno via Bluetooth to smartphone and it can be analyzed by user and sent it to expert doctor with a little cost and more efficiently. This project relates to a pulse rate measurement device comprising a pulse rate sensor unit that detects a user’s pulse rate , a signal processing unit that receives and processes the signal generated from the sensor and a wireless signal transmitting unit that takes the signal from the processing unit and the transmit the signal out to the configured device. The sensor unit almost precisely detects the frequency of change of blood density to get the heart rate, meticulously and efficiency of detection of heart rate, cooperating the technique of wireless transmission, and thus our purpose of promoting accuracy of detection and improving convenience of using is achieved. The model encompasses of Arduino Uno, Pulse Rate Sensor, Bluetooth Board, Breadboard, USB cable etc. We transmit the data via Bluetooth to Smartphone using Pulse Rate Monitor circuit equipped with Arduino Uno.