Search results for: optical limiting

Authors: Ojin Kwon, Yong-Jin Yoon, Liu Xin, Zhang Hongbao

Abstract:

Wireless Body Area Network (WBAN) is a short-range wireless communication around human body for various applications such as wearable devices, entertainment, military, and especially medical devices. WBAN attracts the attention of continuous health monitoring system including diagnostic procedure, early detection of abnormal conditions, and prevention of emergency situations. Compared to cellular network, WBAN system is more difficult to control inter- and inner-cell interference due to the limited power, limited calculation capability, mobility of patient, and non-cooperation among WBANs. In this paper, we compare the performance of resource allocation scheme based on several Pseudo Orthogonal Codewords (POCs) to mitigate inter-WBAN interference. Previously, the POCs are widely exploited for a protocol sequence and optical orthogonal code. Each POCs have different properties of auto- and cross-correlation and spectral efficiency according to its construction of POCs. To identify different WBANs, several different pseudo orthogonal patterns based on POCs exploits for resource allocation of WBANs. By simulating these pseudo orthogonal resource allocations of WBANs on MATLAB, we obtain the performance of WBANs according to different POCs and can analyze and evaluate the suitability of POCs for the resource allocation in the WBANs system.

Keywords: wireless body area network, body sensor network, resource allocation without feedback, interference mitigation, pseudo orthogonal pattern

Procedia PDF Downloads 347

Authors: Mohsen Azarmjoo, Mehdi Mehdizadeh Koupaei, Maryam Mehdizadeh Koupaei, Asghar Mahdlouei Azar

Abstract:

The increasing prevalence of wireless networks in our daily lives has made them indispensable. The aim of this research is to investigate the management of information transfer in wireless networks and the integration of renewable solar energy resources in a residential building. The focus is on the transmission of electricity and information through wireless networks, as well as the utilization of sensors and wireless fire alarm systems. The research employs a descriptive approach to examine the transmission of electricity and information on a wireless network with electric and optical telephone lines. It also investigates the transmission of signals from sensors and wireless fire alarm systems via radio waves. The methodology includes a detailed analysis of security, comfort conditions, and costs related to the utilization of wireless networks and renewable solar energy resources. The study reveals that it is feasible to transmit electricity on a network cable using two pairs of network cables without the need for separate power cabling. Additionally, the integration of renewable solar energy systems in residential buildings can reduce dependence on traditional energy carriers. The use of sensors and wireless remote information processing can enhance the safety and efficiency of energy usage in buildings and the surrounding spaces.

Keywords: renewable energy, intelligentization, wireless sensors, fire alarm system

Procedia PDF Downloads 50

Authors: Elmineh Tsegahun Gedif

Abstract:

Zinc oxide nanoparticles (ZnO NPs) have attracted huge attention due to catalytic, optical, photonic, and antibacterial activity. Zinc oxide nanoparticles were successfully synthesized via a fast, non-toxic, cost-effective, and eco-friendly method by biologically reducing Zn(NO3)2.6H2O solution with Neem (Azadirachta indica) leaf extract under optimum conditions (pH = 9). The presence of active flavonoids, phenolic groups, alkaloids, terpenoids, and tannins, which were in the biomass of the Neem leaf extract before and after reduction, was identified using qualitative screening methods (observing the color changes) and FT-IR Spectroscopy. The formation of ZnO NPs was visually indicated by the color changes from colorless to light yellow color. Biosynthesized nanoparticles were also characterized by UV-visible, FT-IR, and XRD spectroscopies. The reduction process was simple and convenient to handle and was monitored by UV-visible spectroscopy that showed surface plasmon resonance (SPR) of the ZnO NPs at 321 nm. This result clearly revealed the formation of ZnO NPs. X-ray diffraction was used to investigate the crystal structure. The average particle size of ZnO powder and around 20 nm using the line width of the plane, and the refraction peak using Scherrer’s equation. The synthesized zinc oxide nanoparticles were evaluated for antimicrobial activities against Gram-positive and Gram-negative bacteria. Zinc nanoparticles exhibited the maximum zone of inhibition against Escherichia coli (15 mm), while the least activity was seen against Staphylococcus aureus.

Keywords: antimicrobial activity, azadirachta indica, green synthesis, ZnO NPs

Procedia PDF Downloads 100

Authors: C. V. Aravinda, H. N. Prakash

Abstract:

In this paper, we tried to convey fusion and state of art pertaining to SIL character recognition systems. In the first step, the text is preprocessed and normalized to perform the text identification correctly. The second step involves extracting relevant and informative features. The third step implements the classification decision. The three stages which involved are Data acquisition and preprocessing, Feature extraction, and Classification. Here we concentrated on two techniques to obtain features, Feature Extraction & Feature Selection. Edge-hinge distribution is a feature that characterizes the changes in direction of a script stroke in handwritten text. The edge-hinge distribution is extracted by means of a windowpane that is slid over an edge-detected binary handwriting image. Whenever the mid pixel of the window is on, the two edge fragments (i.e. connected sequences of pixels) emerging from this mid pixel are measured. Their directions are measured and stored as pairs. A joint probability distribution is obtained from a large sample of such pairs. Despite continuous effort, handwriting identification remains a challenging issue, due to different approaches use different varieties of features, having different. Therefore, our study will focus on handwriting recognition based on feature selection to simplify features extracting task, optimize classification system complexity, reduce running time and improve the classification accuracy.

Keywords: word segmentation and recognition, character recognition, optical character recognition, hand written character recognition, South Indian languages

Procedia PDF Downloads 488

Authors: Erhan Zor, Funda Copur, Asli I. Dogan, Haluk Bingol

Abstract:

Current trends in the wide-scale sensing technologies rely on the development of miniaturized, rapid and easy-to-use sensing platforms. Quantum dots (QDs) with strong and easily tunable luminescence and high emission quantum yields have become a well-established photoluminescent nanomaterials for sensor applications. Although the majority of the reports focused on the cadmium-based QDs which have toxic effect on biological systems and eventually would cause serious environmental problems, carbon-based quantum dots (CQDs) that do not contain any toxic class elements have attracted substantial research interest in recent years. CQDs are small carbon nanostructures (less than 10 nm in size) with various unique properties and are widely-used in different fields during the last few years. In this respect, chiral nanostructures have become a promising class of materials in various areas such as pharmacology, catalysis, bioanalysis and (bio)sensor technology due to the vital importance of chirality in living systems. We herein report the synthesis of chiral CQDs with D- or L-tartaric acid as precursor materials. The optimum experimental conditions were examined and the purification procedure was performed using ethanol/water by column chromatography. The purified chiral CQDs were characterized by UV-Vis, FT-IR, XPS, PL and TEM techniques. The resultants display different photoluminescent characteristics due to the size and conformational difference. Considering the results, it can be concluded that chiral CQDs is expected to be used as optical chiral sensor in different platforms.

Keywords: carbon quantum dots, chirality, sensor, tartaric acid

Procedia PDF Downloads 236

Authors: Huawei Bai, Jianguo Yao, Fellow, IEEE

Abstract:

Atrial fibrillation (AF) is the most common form of heart arrhythmia and is closely associated with mortality and morbidity in heart failure, stroke, and coronary artery disease. The development of single spot optical sensors enables widespread photoplethysmography (PPG) screening, especially for AF, since it represents a more convenient and noninvasive approach. To our knowledge, most existing studies based on public and unbalanced datasets can barely handle the multiple noises sources in the real world and, also, lack interpretability. In this paper, we construct a large- scale PPG dataset using measurements collected from PPG wrist- watch devices worn by volunteers and propose an attention-based two-stream heterogeneous neural network (TSHNN). The first stream is a hybrid neural network consisting of a three-layer one-dimensional convolutional neural network (1D-CNN) and two-layer attention- based bidirectional long short-term memory (Bi-LSTM) network to learn representations from temporally sampled signals. The second stream extracts latent representations from the PPG time-frequency spectrogram using a five-layer CNN. The outputs from both streams are fed into a fusion layer for the outcome. Visualization of the attention weights learned demonstrates the effectiveness of the attention mechanism against noise. The experimental results show that the TSHNN outperforms all the competitive baseline approaches and with 98.09% accuracy, achieves state-of-the-art performance.

Keywords: PPG wearables, atrial fibrillation, feature fusion, attention mechanism, hyber network

Procedia PDF Downloads 111

Authors: Magdalena Wilk-Kozubek, Jakub Pawłów, Maciej Czajkowski, Maria Zdończyk, Katarzyna Ślepokura, Joanna Cybińska

Abstract:

Thermochromic materials belong to the family of intelligent materials that change their color in response to temperature changes; this ability is called thermochromism. Thermochromic behavior can be displayed by both isolated compounds and multicomponent mixtures. Fluoran leuco dye-based mixtures are well-known thermochromic systems used, for example, in heat-sensitive FAX paper. Weak acids often serve as color developers for such systems. As the temperature increases, the acids melt, and the mixtures become colored. The objective of this research is to determine the influence of acids showing a liquid crystalline nematic phase on the development of the fluoran dye. For this purpose, fluoran-based mixtures with 4-n-alkylbenzoic acids were prepared. The mixtures are colored at room temperature, but they become colorless upon the melting of the acids. The melting of acids is associated not only with a change in the color of the mixtures but also with a change in their emission color. Phase transitions were investigated by temperature-dependent powder X-ray diffraction and differential scanning calorimetry; nematic phases were visualized by polarized optical microscopy, and color and emission changes were studied by UV-Vis diffuse reflectance and photoluminescence spectroscopies, respectively. When 4-n-alkylbenzoic acids are used as color developers, the fluoran-based mixtures become colorless after the melting of the acids. This is because the melting of acids is accompanied by the transition from the crystalline phase to the nematic phase, in which the molecular arrangement of the acids does not allow the fluoran dye to be developed.

Keywords: color developer, leuco dye, liquid crystal, thermochromism

Procedia PDF Downloads 92

Authors: Alexander Rodríguez-Hernández, Arnulfo Rojas-Perez, Liz Diaz-Vazquez

Abstract:

The rise in consumerism over the past century has resulted in the creation of higher amounts of plasticizers, personal care products and other chemical substances, which enter and accumulate in water systems. Other sources of pollutants in Neotropical regions experience large inputs of nutrients with these pollutants resulting in eutrophication of water which consume large quantities of oxygen, resulting in high fish mortality. This dilemma has created a need for the development of targeted detection in complex matrices and remediation of emerging contaminants. We have synthesized carbon nanoparticles from macro algae (Ulva fasciata) by oxidizing the graphitic carbon network under extreme acidic conditions. The resulting material was characterized by STEM, yielding a spherical 12 nm average diameter nanoparticles, which can be fixed into a polysaccharide aerogel synthesized from the same macro algae. Spectrophotometer analyses show a pH dependent fluorescent behavior varying from 450-620 nm in aqueous media. Heavily oxidized edges provide for easy functionalization with enzymes for a more targeted analysis and remediation technique. Given the optical properties of the carbon base nanoparticles and the numerous possibilities of functionalization, we have developed a selective and robust targeted bio-detection and bioremediation technique for the treatment of emerging contaminants in complex matrices like estuarine embayment.

Keywords: aerogels, carbon nanoparticles, fluorescent, targeted analysis

Procedia PDF Downloads 236

Authors: Anjela Koblischka-Veneva, Michael R. Koblischka

Abstract:

In this contribution, the Transmission-Kikuchi Diffraction (TKD, or sometimes called t-EBSD) is applied to bulk, melt-grown YBa₂Cu₃O₇ (YBCO) superconductors prepared by the MTMG (melt-textured melt-grown) technique and the infiltration growth (IG) technique. TEM slices required for the analysis were prepared by means of Focused Ion-Beam (FIB) milling using mechanically polished sample surfaces, which enable a proper selection of the interesting regions for investigations. The required optical transparency was reached by an additional polishing step of the resulting surfaces using FIB-Ga-ion and Ar-ion milling. The improved spatial resolution of TKD enabled the investigation of the tiny YBa₂Cu₃O₅ (Y-211) particles having a diameter of about 50-100 nm embedded within the YBCO matrix and of other added secondary phase particles. With the TKD technique, the microstructural properties of the YBCO matrix are studied in detail. It is observed that the matrix shows the effects of stress/strain, depending on the size and distribution of the embedded particles, which are important for providing additional flux pinning centers in such superconducting bulk samples. Using the Kernel Average Misorientation (KAM) maps, the strain induced in the superconducting matrix around the particles, which increases the flux pinning effectivity, can be clearly revealed. This type of analysis of the EBSD/TKD data is, therefore, also important for other material systems, where nanoparticles are embedded in a matrix.

Keywords: transmission Kikuchi diffraction, EBSD, TKD, embedded particles, superconductors YBa₂Cu₃O₇

Procedia PDF Downloads 130

Authors: Eitedal Daoud, Reda M.Daoud, Khaled Abdel-Wahhab, Maha M.Saber, Lobna Saber

Abstract:

Background: Cis-platin is a widely used chemotherapeutic drug to treat many malignant disorders including head and neck malignancies. Oto-nephrotxicity is an important and dose - limiting side effect of cis - platin therapy. Nowadays, more attention had been paid to oto-toxicity caused with cis-platin. Aim of the Work: This study was designed to investigate the potential protective effect of Whey protein (WP) against cis-platin induced ototoxicity compared to the effect of N-acetylcysteine (NAC) in rats. Methodology: Male albino rats were randomly divided into 6 groups: untreated rats (control), rats orally treated with whey protein (1g/kg b.w/day) for seven executive days, rats treated orally with N-acetylcysteine (500 mg/kgb.w /day) for seven executive days, rates intoxicated intraperitoneal (ip) with cis- platin (10 mg/kgb.w. once), rats treated with whey protein (1g/kgb.w./day) for seven executive days) followed by one injection (ip) of cis-platin(10 mg/kg b.w.) one hour after the last oral administration of whey protein, rats treated with N- acetylcysteine (for seven executive days followed by one injection (ip) of cis-platin (10 mg/kgb.w) one hour after the last oral administration of N-acetylcysteine. The organ of Corti, the stria vascularis and spiral ganglia were visualized by light microscopy at different magnifications. Results: Cis-platin intoxicated animals showed a significant decrease in serum level of total antioxidant capacity (TAC),with inhibition in the activity of serum glutathione-s transferase(GST) and paraoxonnase-1 (PON-1) in comparison with control. Group treated with either NAC or WP with cis-platin showed significant elevation in the activity of both GST & PON-1 with increased serum level of TAC when compared with cis-platin intoxicated rats. Animals treated with NAC or WP with cis-platin compared to those treated with cis-platin alone showed marked degree of improvement towards control rats as there was significant drop in the serum level of cortecosterone, nitric oxide (NO), and melandialdehyde (MDA).Histopathologic, in NAC pretreated group there was no changes in stria vascularis or spiral ganglia. In group pretreated with WP, there was no histopathologic alteration detected in the organ of Corti and Reissers membrane but oedema and haemorrhage were founded in the stria vascularis in small focal manner. Conclusion: Our finding showed that Whey protein is a natural dietary supplement product proved its ability of protection of anti-oxidant system and the cochlea against cis-platin induced ototoxicity.

Keywords: anti-oxidant, cis-platin, N-acetylcysteine, ototoxicity, whey protein

Procedia PDF Downloads 517

Authors: Suriya

Abstract:

Rapid socio-economic development and urbanization have led to an increasingly serious air pollution problem in Ulaanbaatar (UB), the capital of Mongolia. PM₂.₅ pollution has become the most pressing aspect of UB air pollution. Therefore, monitoring and predicting PM₂.₅ concentration in UB is of great significance for the health of the local people and environmental management. As of yet, very few studies have used models to predict PM₂.₅ concentrations in UB. Using data from 0:00 on June 1, 2018, to 23:00 on April 30, 2020, we proposed two deep learning models based on Bayesian-optimized LSTM (Bayes-LSTM) and CNN-LSTM. We utilized hourly observed data, including Himawari8 (H8) aerosol optical depth (AOD), meteorology, and PM₂.₅ concentration, as input for the prediction of PM₂.₅ concentrations. The correlation strengths between meteorology, AOD, and PM₂.₅ were analyzed using the gray correlation analysis method; the comparison of the performance improvement of the model by using the AOD input value was tested, and the performance of these models was evaluated using mean absolute error (MAE) and root mean square error (RMSE). The prediction accuracies of Bayes-LSTM and CNN-LSTM deep learning models were both improved when AOD was included as an input parameter. Improvement of the prediction accuracy of the CNN-LSTM model was particularly enhanced in the non-heating season; in the heating season, the prediction accuracy of the Bayes-LSTM model slightly improved, while the prediction accuracy of the CNN-LSTM model slightly decreased. We propose two novel deep learning models for PM₂.₅ concentration prediction in UB, Bayes-LSTM, and CNN-LSTM deep learning models. Pioneering the use of AOD data from H8 and demonstrating the inclusion of AOD input data improves the performance of our two proposed deep learning models.

Keywords: deep learning, AOD, PM2.5, prediction, Ulaanbaatar

Procedia PDF Downloads 41

Authors: Giuliana Scuderi, Patrick Teuffel

Abstract:

The proven vulnerability of the existing social housing building heritage to natural or induced earthquakes requires the development of new design concepts and conceptual method to preserve materials and object, at the same time providing new performances. An integrate intervention between civil engineering, building physics and architecture can convert the social housing districts from a critical part of the city to a strategic resource of revitalization. Referring to bio-mimicry principles the present research proposes a taxonomy with the exoskeleton of the insect, an external, light and resistant armour whose role is to protect the internal organs from external potentially dangerous inputs. In the same way, a “building exoskeleton”, acting from the outside of the building as an enclosing cage, can restore, protect and support the existing building, assuming a complex set of roles, from the structural to the thermal, from the aesthetical to the functional. This study evaluates the structural efficiency of shape memory alloys devices (SMADs) connecting the “building exoskeleton” with the existing structure to rehabilitate, in order to prevent the out-of-plane collapse of walls and for the passive dissipation of the seismic energy, with a calibrated operability in relation to the intensity of the horizontal loads. The two case studies of a masonry structure and of a masonry structure with concrete frame are considered, and for each case, a theoretical social housing building is exposed to earthquake forces, to evaluate its structural response with or without SMADs. The two typologies are modelled with the finite element program SAP2000, and they are respectively defined through a “frame model” and a “diagonal strut model”. In the same software two types of SMADs, called the 00-10 SMAD and the 05-10 SMAD are defined, and non-linear static and dynamic analyses, namely push over analysis and time history analysis, are performed to evaluate the seismic response of the building. The effectiveness of the devices in limiting the control joint displacements resulted higher in one direction, leading to the consideration of a possible calibrated use of the devices in the different walls of the building. The results show also a higher efficiency of the 00-10 SMADs in controlling the interstory drift, but at the same time the necessity to improve the hysteretic behaviour, to maximise the passive dissipation of the seismic energy.

Keywords: adaptive structure, biomimetic design, building exoskeleton, social housing, structural envelope, structural retrofitting

Procedia PDF Downloads 416

Authors: Savitha Janakiraman, Shivakumar M. C

Abstract:

Anidulafungin, an advanced class of antifungal agent used for the treatment of chronic fungal infections, is derived from Echinocandin B nucleus, an intermediate metabolite of Echinocandin B produced by Aspergillus nidulans. The enzyme acylase derived from the fermentation broth of Actinoplanes utahensis (NRRL 12052) plays a key role in the bioconversion of echinocandin B to echinocandin B nucleus. The membrane-bound nature of acylase and low levels of expression contributes to the rate-limiting process of enzymatic deacylation, hence low yields of ECB nucleus and anidulafungin. In the present study, this is addressed through novel genetic engineering approaches of overexpression and heterologous expression studies, immobilization of whole cells of Actinoplanes utahensis (NRRL 12052) and Co-cultivation studies. Overexpression of the acylase gene in Actinoplanes utahensis (NRRL 12052) was done by increasing the gene copy number to increase the echinocandin B nucleus production. Echinocandin B acylase gene, under the control of a PermE* promoter, was cloned in pSET152 vector and introduced into Actinoplanes utahensis (NRRL12052) by a ɸC31-directed site-specific recombination method. The resultant recombinant strain (C2-18) showed a 3-fold increase in acylase expression, which was confirmed by HPLC analysis. Pichia pastoris is one of the most effective and versatile host systems for the production of heterologous proteins. The ECB acylase gene was cloned into pPIC9K vector with AOX1 promoter and was transformed into Pichia pastoris (GS115). The acylase expression was confirmed by protein expression and bioconversion studies. The heterologous expression of acylase in Pichia pastoris, is a milestone in the development of antifungals. Actively growing cells of Actinoplanes utahensis (NRRL 12052) were immobilized and tested for bioconversion ability which showed >90% conversion in each cycle. The stability of immobilized cell beads retained the deacylation ability up to 60 days and reusability was confirmed up to 4 cycles. The significant findings from the study have revealed that immobilization of whole cells of Actinoplanes utahensis (NRRL 12052) could be an alternative option for bioconversion of echinocandin B to echinocandin B nucleus, which has not been reported to date. The concept of co-cultivation of Aspergillus nidulans and Actinoplanes utahensis strains for the production of the echinocandin B nucleus was also carried out in order to produce echinocandin B nucleus. The process completely reduced the ECB purification step and, therefore, could be recommended as an ingenious method to improve the yield of the ECB nucleus.

Keywords: acylase, anidulafungin, antifungals, Aspergillus nidulans

Procedia PDF Downloads 100

Authors: Maria Cherepanova, Svetlana Maximova

Abstract:

Background And Aims: Suicide is among ten most common causes of death of the working-age population in the world. According to the WHO forecasts, by 2025 suicide will be the third leading cause of death, after cardiovascular diseases and cancer. In 2019, the global suicide rate in the world was 10,5 per 100,000 people. In Russia, the average figure was 11.6. However, in some depressed regions of Russia, such as Buryatia and Altai, it reaches 35.3. The aim of this study was to develop models based on the regional factors of social well-being deprivation that provoke the suicidal risk of various age groups of Russian population. We also investigated suicidal risk prevention in modern Russia, analyzed its efficacy, and developed recommendations for suicidal risk prevention improvement. Methods: In this study, we analyzed the data from sociological surveys from six regions of Russia. Totally we interviewed 4200 people, the age of the respondents was from 16 to 70 years. The results were subjected to factorial and regression analyzes. Results: The results of our study indicate that young people are especially socially vulnerable, which result in ineffective patterns of self-preservation behavior and increase the risk of suicide. That is due to lack of anti-suicidal barriers formation; low importance of vital values; the difficulty or impossibility to achieve basic needs; low satisfaction with family and professional life; and decrease in personal unconditional significance. The suicidal risk of the middle-aged population is due to a decrease in social well-being in the main aspects of life, which determines low satisfaction, decrease in ontological security, and the prevalence of auto-aggressive deviations. The suicidal risk of the elderly population is due to increased factors of social exclusion which result in narrowing the social space and limiting the richness of life. Conclusions: The existing system for lowering suicide risk in modern Russia is predominantly oriented to a medical treatment, which provides only intervention to people who already committed suicide, that significantly limits its preventive effectiveness and social control of this deviation. The national strategy for suicide risk reduction in modern Russian society should combine medical and social activities, designed to minimize possible situations resulting to suicide. The strategy for elimination of suicidal risk should include a systematic and significant improvement of the social well-being of the population and aim at overcoming the basic aspects of social disadvantages such as poverty, unemployment as well as implementing innovative mental health improvement, developing life-saving behavior that will help to counter suicides in Russia.

Keywords: social factors, suicide, prevention, Russia

Procedia PDF Downloads 165

Authors: Mariana Gomez Gomez, Maria Elena Sanchez Vergara

Abstract:

Many sustainable approaches to generate electric energy have emerged in the last few decades; one of them is through solar cells. Yet, this also has the disadvantage of highly polluting inorganic semiconductor manufacturing processes. Therefore, the use of molecular semiconductors must be considered. In this work, allene compounds C24H26O4 and C24H26O5 were used as dopants to manufacture semiconductors films based on PbPc by high-vacuum evaporation technique. IR spectroscopy was carried out to determine the phase and any significant chemical changes which may occur during the thermal evaporation. According to UV-visible spectroscopy and Tauc’s model, the deposition process generated thin films with an activation energy range of 1.47 to 1.55 eV for direct transitions and 1.29 to 1.33 eV for indirect transitions. These values place the manufactured films within the range of low bandgap semiconductors. The flexible devices were manufactured: polyethylene terephthalate (PET), Indium tin oxide (ITO)/organic semiconductor/ Cubic Close Packed (CCP). The characterization of the devices was carried out by evaluating electrical conductivity using the four-probe collinear method. I-V curves were obtained under different lighting conditions at room temperature. OS1 (PbPc/C24H26O4) showed an Ohmic behavior, while OS2 (PbPc/C24H26O5) reached higher current values ​​at lower voltages. The results obtained show that the semiconductors devices doped with allene compounds can be used in the manufacture of optoelectronic devices.

Keywords: electrical properties, optical gap, phthalocyanine, thin film.

Procedia PDF Downloads 245

Authors: Oluwagbenga B. Fatile, Felix U. Idu, Olajide T. Sanya

Abstract:

This paper reports the viability of developing Zn-27Al alloy matrix hybrid composites reinforced with alumina, graphite and fly ash (a solid waste byproduct of coal in thermal power plants). This research work was aimed at developing low cost-high performance Zn-27Al matrix composite with low density. Alumina particulates (Al2O3), graphite added with 0, 2, 3, 4, and 5 wt% fly ash were utilized to prepare 10wt% reinforcing phase with Zn-27Al alloy as matrix using two-step stir casting method. Density measurement estimated percentage porosity, tensile testing, micro hardness measurement, and optical microscopy were used to assess the performance of the composites produced. The results show that the hardness, ultimate tensile strength, and percent elongation of the hybrid composites decrease with increase in fly ash content. The maximum decrease in hardness and ultimate tensile strength of 13.72% and 15.25% respectively were observed for composite grade containing 5wt% fly ash. The percentage elongation of composite sample without fly ash is 8.9% which is comparable with that of the sample containing 2wt% fly ash with percentage elongation of 8.8%. The fracture toughness of the fly ash containing composites was, however, superior to those of composites without fly ash with 5wt% fly ash containing composite exhibiting the highest fracture toughness. The results show that fly ash can be utilized as complementary reinforcement in ZA-27 alloy matrix composite to reduce cost.

Keywords: fly ash, hybrid composite, mechanical behaviour, stir-cast

Procedia PDF Downloads 331

Authors: Marcelo Sanhueza Cartes, Nelson Maureira Carsalade

Abstract:

This research evaluates the effectiveness of a pallet isolation device for the protection of selective-type industrial storage racks. The device works only in the longitudinal direction of the aisle, and it is made up of a platform installed on the rack beams. At both ends, the platform is connected to the rack structure by means of a spring-damper system working in parallel. A system of wheels is arranged between the isolation platform and the rack beams in order to reduce friction, decoupling of the movement and improve the effectiveness of the device. The latter is evaluated by the reduction of the maximum dynamic responses of basal shear load and story drift in relation to those corresponding to the same rack with the traditional construction system. In the first stage, numerical simulations of industrial storage racks were carried out with and without the pallet isolation device. The numerical results allowed us to identify the archetypes in which it would be more appropriate to carry out experimental tests, thus limiting the number of trials. In the second stage, experimental tests were carried out on a shaking table to a select group of full-scale racks with and without the proposed device. The movement simulated by the shaking table was based on the Mw 8.8 magnitude earthquake of February 27, 2010, in Chile, registered at the San Pedro de la Paz station. The peak ground acceleration (PGA) was scaled in the frequency domain to fit its response spectrum with the design spectrum of NCh433. The experimental setup contemplates the installation of sensors to measure relative displacement and absolute acceleration. The movement of the shaking table with respect to the ground, the inter-story drift of the rack and the pallets with respect to the rack structure were recorded. Accelerometers redundantly measured all of the above in order to corroborate measurements and adequately capture low and high-frequency vibrations, whereas displacement and acceleration sensors are respectively more reliable. The numerical and experimental results allowed us to identify that the pallet isolation period is the variable with the greatest influence on the dynamic responses considered. It was also possible to identify that the proposed device significantly reduces both the basal cut and the maximum inter-story drift by up to one order of magnitude.

Keywords: pallet isolation system, industrial storage racks, basal shear load, interstory drift.

Procedia PDF Downloads 71

Authors: J. Subbalakshmi, G. Dhruvasamhith, S. M. Hussain

Abstract:

Polyaniline (PANI) is one of the most extensively studied material among the conducting polymers due to its simple synthesis by chemical and electrochemical routes. PANIs have advantages of chemical stability and high conductivity making their commercial applications quite attractive. However, to our knowledge, very little work has been reported on the tensile strength properties of templated PANIs processed with polyvinyl alcohol and also, detailed study has not been carried out. We have investigated the effect of small molecule and polymers as templates on PANI. Stable aqueous colloidal suspensions of trisodium citrate (TSC), poly(ethylenedioxythiophene)-polystyrene sulfonate (PEDOT-PSS), and polyethylene glycol (PEG) templated PANIs were prepared through chemical synthesis, processed with polyvinyl alcohol (PVA) and were fabricated into films by solution casting. Absorption and infra-red spectra were studied to gain insight into the possible molecular interactions. Surface morphology was studied through scanning electron microscope and optical microscope. Interestingly, tensile testing studies revealed least strain for pure PVA when compared to the blends of templated PANI. Furthermore, among the blends, TSC templated PANI possessed maximum elasticity. The ultimate tensile strength for PVA processed, PEG-templated PANI was found to be five times more than other blends considered in this study. We establish structure–property correlation with morphology, spectral characterization and tensile testing studies.

Keywords: surface morphology, processed films, polyvinyl alcohol, templated polyanilines, tensile testing

Procedia PDF Downloads 207

Authors: Nassier A. Nassir, Robert Birch, D. Rico Sierra, S. P. Edwardson, G. Dearden, Zhongwei Guan

Abstract:

The effect of laser surface treatment parameters on the residual strength of titanium alloy has been investigated. The influence of the laser surface treatment on the bonding strength between the titanium and poly-ether-ketone-ketone (PEKK) surfaces was also evaluated and compared to those offered by titanium foils without surface treatment to optimize the laser parameters. Material characterization using an optical microscope was carried out to study the microstructure and to measure the mean roughness value of the titanium surface. The results showed that the surface roughness shows a significant dependency on the laser power parameters in which surface roughness increases with the laser power increment. Moreover, the results of the tensile tests have shown that there is no significant dropping in tensile strength for the treated samples comparing to the virgin ones. In order to optimize the laser parameter as well as the corresponding surface roughness, single-lap shear tests were conducted on pairs of the laser treated titanium stripes. The results showed that the bonding shear strength between titanium alloy and PEKK film increased with the surface roughness increment to a specific limit. After this point, it is interesting to note that there was no significant effect for the laser parameter on the bonding strength. This evidence suggests that it is not necessary to use very high power of laser to treat titanium surface to achieve a good bonding strength between titanium alloy and the PEKK film.

Keywords: bonding strength, laser surface treatment, PEKK, poly-ether-ketone-ketone, titanium alloy

Procedia PDF Downloads 334

Authors: Andy Zhang, Awnik Roy, Trevor B. Chen, Bibik Oleksandr, Subodh Adhikari, Paul S. Hsu

Abstract:

The durability of a combustor in gas-turbine enginesrequiresa good control of its component temperatures. Since the temperature of combustion gases frequently exceeds the melting point of the combustion liner walls, an efficient air-cooling system is significantly important to elongatethe lifetime of liner walls. To determine the effectiveness of the air-cooling system, accurate 2D surface temperature measurement of combustor liner walls is crucial for advanced engine development. Traditional diagnostic techniques for temperature measurement, such as thermocouples, thermal wall paints, pyrometry, and phosphors, have shown disadvantages, including being intrusive and affecting local flame/flow dynamics, potential flame quenching, and physical damages to instrumentation due to harsh environments inside the combustor and strong optical interference from strong combustion emission in UV-Mid IR wavelength. To overcome these drawbacks, a compact and small borescope long-wave-infrared (LWIR) sensor is developed to achieve two-dimensional high-spatial resolution, high-fidelity thermal imaging of 2D surface temperature in gas-turbine engines, providing the desired engine component temperature distribution. The compactLWIRborescope sensor makes it feasible to promote the durability of combustor in gas-turbine engines.

Keywords: borescope, engine, long-wave-infrared, sensor

Procedia PDF Downloads 124

Authors: Chien-Hung Liu, Yu-Fen Chen

Abstract:

This study used triangular laser probe and three-axial direction mobile platform for surface measurement, programmed it and applied it to real-time analytic statistics of different measured data. This structure was used to design a system integration program: using triangular laser probe for scattering or reflection non-contact measurement, transferring the captured signals to the computer through RS-232, and using RS-485 to control the three-axis platform for a wide range of measurement. The data captured by the laser probe are formed into a 3D surface. This study constructed an optical measurement application program in the concept of visual programming language. First, the signals are transmitted to the computer through RS-232/RS-485, and then the signals are stored and recorded in graphic interface timely. This programming concept analyzes various messages, and makes proper presentation graphs and data processing to provide the users with friendly graphic interfaces and data processing state monitoring, and identifies whether the present data are normal in graphic concept. The major functions of the measurement system developed by this study are thickness measurement, SPC, surface smoothness analysis, and analytical calculation of trend line. A result report can be made and printed promptly. This study measured different heights and surfaces successfully, performed on-line data analysis and processing effectively, and developed a man-machine interface for users to operate.

Keywords: laser probe, non-contact measurement, triangulation measurement principle, statistical process control, labVIEW

Procedia PDF Downloads 359

Authors: Zhen Li, Chang Liu, Ping Zhang

Abstract:

These Glaciers are thought of as natural water reservoirs and are of vital importance to hydrological models and industrial production, and glacial changes act as significant indicators of climate change. The glacier snowline can be used as an indicator of the equilibrium line, which may be a key parameter to study the effect of climate change on glaciers. Using Google Earth Engine, we select optical satellite imageries and implement the Otsu thresholding method on a near-infrared band to detect snowline altitudes (SLAs) of 26 glaciers in three regions of the eastern Tibetan Plateau. Three different study regions in the eastern Tibetan Plateau have different climate regimes, which are Sepu Kangri (SK, maritime glacier), Bu’Gyai Kangri (BK, continental glacier) and west of Qiajajima (WQ, continental glacier), along a latitudinal transect from south to north. We analyzed the effects of climatic factors on the SLA changes from 1995 to 2016. SLAs are fluctuating upward, and the rising values are 100 m, 60 m, and 34 m from south to north during the 22 years. We also observed that the climatic factor that affects the variability of SLA gradually changes from precipitation to temperature from south to north. The northern continental glaciers are mainly affected by temperature, and the southern maritime glaciers affected by precipitation. Owing to the influence of primary climatic factors, continental glaciers are found to have higher SLAs on the south slope, while maritime glaciers have higher SLAs on the north slope.

Keywords: climate change, glacier, snowline altitude, tibetan plateau

Procedia PDF Downloads 149

Authors: Sanjeev Kumar Raghuwanshi, Yadvendra Singh

Abstract:

The objective of this paper is to develop and optimize the Fiber Bragg (FBG) grating based Surface Plasmon Resonance (SPR) sensor for monitoring the hazardous toxic chemicals and gases in underground mines or any industrial area. A fully cladded telecommunication standard FBG is proposed to develop to produce surface plasmon resonance. A thin few nm gold/silver film (subject to optimization) is proposed to apply over the FBG sensing head using e-beam deposition method. Sensitivity enhancement of the sensor will be done by adding a composite nanostructured Graphene Oxide (GO) sensing layer using the spin coating method. Both sensor configurations suppose to demonstrate high responsiveness towards the changes in resonance wavelength. The GO enhanced sensor may show increased sensitivity of many fold compared to the gold coated traditional fibre optic sensor. Our work is focused on to optimize GO, multilayer structure and to develop fibre coating techniques that will serve well for sensitive and multifunctional detection of hazardous chemicals. This research proposal shows great potential towards future development of optical fiber sensors using readily available components such as Bragg gratings as highly sensitive chemical sensors in areas such as environmental sensing.

Keywords: surface plasmon resonance, fibre Bragg grating, sensitivity, toxic gases, MATRIX method

Procedia PDF Downloads 263

Authors: Anjela Koblischka-Veneva, Michael Koblischka

Abstract:

In this contribution, the transmission-Kikuchi diffrac-tion (TKD, or sometimes called t-EBSD) is applied to bulk, melt-grown YBa2Cu3O7 (YBCO) superconductors prepared by the MTMG (melt-textured melt-grown) technique and the infiltration (IG) growth technique. TEM slices required for the analysis were prepared by means of focused ion-beam (FIB) milling using mechanically polished sample surfaces, which enable a proper selection of the in-teresting regions for investigations. The required optical transparency was reached by an additional polishing step of the resulting surfaces using FIB-Ga-ion and Ar-ion milling. The improved spatial resolution of TKD enabled the investigation of the tiny Y2BaCuO5 (Y-211) particles having a diameter of about 50-100 nm embedded within the YBCO matrix and of other added secondary phase particles. With the TKD technique, the microstructural properties of the YBCO matrix are studied in detail. It is observed that the matrix shows effects of stress/strain, depending on the size and distribution of the embedded particles, which are important for providing additional flux pinning centers in such superconducting bulk samples. Using the Kernel average misorientation (KAM) maps, the strain induced in the superconducting matrix around the particles, which increases the flux pinning effectivity, can be clearly revealed. This type of analysis of the EBSD/TKD data is, therefore, also important for other material systems, where nanoparticles are embedded in a matrix.

Keywords: electron backscatter Diffraction, transmission Kikuchi diffraction, SEM, YBCO, microstructure, nanoparticles

Procedia PDF Downloads 122

Authors: Yagahira E. Castro-Sesquen, Chloe Kim, Robert H. Gilman, David J. Sullivan, Peter C. Searson

Abstract:

Diagnosis of severe malaria is particularly important in highly endemic regions since most patients are positive for parasitemia and treatment differs from non-severe malaria. Diagnosis can be challenging due to the prevalence of diseases with similar symptoms. Accurate diagnosis is increasingly important to avoid overprescribing antimalarial drugs, minimize drug resistance, and minimize costs. A nanoparticle-based assay for detection and quantification of Plasmodium falciparum histidine-rich protein 2 (HRP2) in urine and serum is reported. The assay uses magnetic beads conjugated with anti-HRP2 antibody for protein capture and concentration, and antibody-conjugated quantum dots for optical detection. Western Blot analysis demonstrated that magnetic beads allows the concentration of HRP2 protein in urine by 20-fold. The concentration effect was achieved because large volume of urine can be incubated with beads, and magnetic separation can be easily performed in minutes to isolate beads containing HRP2 protein. Magnetic beads and Quantum Dots 525 conjugated to anti-HRP2 antibodies allows the detection of low concentration of HRP2 protein (0.5 ng mL-1), and quantification in the range of 33 to 2,000 ng mL-1 corresponding to the range associated with non-severe to severe malaria. This assay can be easily adapted to a non-invasive point-of-care test for classification of severe malaria.

Keywords: HRP2 protein, malaria, magnetic beads, Quantum dots

Procedia PDF Downloads 328

Authors: Goodness Onwuka, Khaled Abou-El-Hossein

Abstract:

Borosilicate-crown (BK7) glass has found broad application in the optic and automotive industries and the growing demands for nanometric surface finishes is becoming a necessity in such applications. Thus, it has become paramount to optimize the parameters influencing the surface roughness of this precision lens. The research was carried out on a 4-axes Nanoform 250 precision lathe machine with an ultra-high precision grinding spindle. The experiment varied the machining parameters of feed rate, wheel speed and depth of cut at three levels for different combinations using Box Behnken design of experiment and the resulting surface roughness values were measured using a Taylor Hobson Dimension XL optical profiler. Acoustic emission monitoring technique was applied at a high sampling rate to monitor the machining process while further signal processing and feature extraction methods were implemented to generate the input to a neural network algorithm. This paper highlights the training and development of a back propagation neural network prediction algorithm through careful selection of parameters and the result show a better classification accuracy when compared to a previously developed response surface model with very similar machining parameters. Hence artificial neural network algorithms provide better surface roughness prediction accuracy in the ultra-high precision grinding of BK7 glass.

Keywords: acoustic emission technique, artificial neural network, surface roughness, ultra-high precision grinding

Procedia PDF Downloads 301

Authors: P. Charipoor, M. Khani, H. Mahmoudi, E. Ghasemi, P. Akbartehrani, B. Shokri

Abstract:

Cold air plasma could have a variety of effects on cells and living organisms and also shows good results in medical and cosmetic cases. Herein, plasma floating electrode dielectric barrier discharge (FEDBD) plasma was designed for mouse skin rejuvenation purposes. It is safe and easy to use in clinics, laboratories, and homes. The effects of this device were investigated on mouse skin. Vitamin C ointment in combination with plasma was also used as a new method to improve FEDBD results. In this study, 20 Wistar rats were evaluated in four groups. The first group received high-dose plasma, the second group received moderate-dose plasma (with vitamin C cream), the third group received low-dose plasma (with vitamin C cream) for 6 minutes, and the fourth group received only vitamin C cream. This process was done 3 times a week for 4 weeks. Skin temperature was monitored to evaluate the thermal effect of plasma. The presence of reactive species was also demonstrated using optical spectroscopy. Mechanical assays were performed to evaluate the effect of plasma and vitamin C on the mechanical strength of the tissue, which showed a positive effect of plasma on the treated tissue compared to the control group. Using pathological and biometric skin tests, an increase in collagen levels, epidermal thickness, and an increase in fibroblasts was observed in rat skin, as well as increased skin elasticity. This study showed the positive effect of using the FEDBD plasma device on the effective parameters in skin rejuvenation.

Keywords: plasma, skin rejuvenation, collagen, epidermal thickness

Procedia PDF Downloads 249

Authors: Ia Kurashvili, Giorgi Darsavelidze, Giorgi Chubinidze, Marina Kadaria

Abstract:

Boron-doped Czochralski (CZ) silicon of p-type, widely used in the photovoltaic industry is suffering from the light-induced-degradation (LID) of bulk electrophysical characteristics. This is caused by specific metastable B-O defects, which are characterized by strong recombination activity. In this regard, it is actual to suppress B-O defects in CZ silicon. One of the methods is doping of silicon by different isovalent elements (Ge, C, Sn). The present work deals with the investigations of the influence of germanium doping on the internal friction and shear modulus amplitude dependences in the temperature interval of 600-800⁰C and 0.5-5 Hz frequency range in boron-containing monocrystalline silicon. Experimental specimens were grown by Czochralski method (CZ) in [111] direction. Four different specimens were investigated: Si+0,5at%Ge:B (5.1015cm-3), Si+0,5at%Ge:B (1.1019cm-3), Si+2at%Ge:B (5.1015cm-3) and Si+2at%Ge:B (1.1019cm-3). Increasing tendency of dislocation density and inhomogeneous distribution in silicon crystals with high content of boron and germanium were revealed by metallographic studies on the optical microscope of NMM-80RF/TRF. Weak increase of current carriers-holes concentration and slight decrease of their mobility were observed by Van der Pauw method on Ecopia HMS-3000 device. Non-monotonous changes of dislocation origin defects mobility and microplastic deformation characteristics influenced by measuring temperatures and boron and germanium concentrations were revealed. Possible mechanisms of changes of mechanical characteristics in Si-Ge experimental specimens were discussed.

Keywords: dislocation, internal friction, microplastic deformation, shear modulus

Procedia PDF Downloads 233

Authors: Bruno R. Mendes, Francisco J. Caldeira, Rita S. Luís

Abstract:

Population ageing is directly correlated to an increase in medicine consumption. Beyond the latter and the polymedicated profile of elderly, it is possible to see a need for pharmacotherapeutic monitoring due to cognitive and physical impairment. In this sense, the tracking, organization and administration of medicines become a daily challenge and the pill-box dispenser system a solution. The pill-box dispenser (system) consists in a small compartmentalized container to unit dose organization, which means a container able to correlate the patient’s prescribed dose regimen and the time schedule of intake. In many European countries, this system is part of pharmacist’s role in clinical pharmacy. Despite this simple solution, therapy compliance is only possible if the patient adheres to the system, so it is important to establish a qualitative and quantitative analysis on the perception of the patient on the benefits and risks of the pill-box dispenser as well as the identification of the ideal system. The analysis was conducted through an observational study, based on the application of a standardized questionnaire structured with the numerical scale of Likert (5 levels) and previously validated on the population. The study was performed during a limited period of time and under a randomized sample of 188 participants. The questionnaire consisted of 22 questions: 6 background measures and 16 specific measures. The standards for the final comparative analysis were obtained through the state-of-the-art on the subject. The study carried out using the Likert scale afforded a degree of agreement and discordance between measures (Sample vs. Standard) of 56,25% and 43,75%, respectively. It was concluded that the pill-box dispenser has greater acceptance among a younger population, that was not the initial target of the system. However, this allows us to guarantee a high adherence in the future. Additionally, it was noted that the cost associated with this service is not a limiting factor for its use. The pill-box dispenser system, as currently implemented, demonstrates an important weakness regarding the quality and effectiveness of the medicines, which is not understood by the patient, revealing a significant lack of literacy when it concerns with medicine area. The characteristics of an ideal system remain unchanged, which means that the size, appearance and availability of information in the pill-box continue to be indispensable elements for the compliance with the system. The pill-box dispenser remains unsuitable regarding container size and the type of treatment to which it applies. Despite that, it might be a future standard for clinical pharmacy, allowing a differentiation of the pharmacist role, as well as a wider range of applications to other age groups and treatments.

Keywords: clinical pharmacy, medicines, patient safety, pill-box dispenser

Procedia PDF Downloads 189

Authors: Marcus Klein, Martina GrießBach, Richard Kupke

Abstract:

The current advances in the research and manufacturing of large area graphene layers are promising towards the introduction of this exciting material in the display industry and other applications that benefit from excellent electrical and optical characteristics. New production technologies in the fabrication of flexible displays, touch screens or printed electronics apply graphene layers on non-metal substrates and bring new challenges to the required metrology. Traditional measurement concepts of layer thickness, sheet resistance, and layer uniformity, are difficult to apply to graphene production processes and are often harmful to the product layer. New non-contact sensor concepts are required to adapt to the challenges and even the foreseeable inline production of large area graphene. Dedicated non-contact measurement sensors are a pioneering method to leverage these issues in a large variety of applications, while significantly lowering the costs of development and process setup. Transferred and printed graphene layers can be characterized with high accuracy in a huge measurement range using a very high resolution. Large area graphene mappings are applied for process optimization and for efficient quality control for transfer, doping, annealing and stacking processes. Examples of doped, defected and excellent Graphene are presented as quality images and implications for manufacturers are explained.

Keywords: graphene, doping and defect testing, non-contact sheet resistance measurement, inline metrology

Procedia PDF Downloads 305