Search results for: brain cooling
714 Synthesis and Characterization of New Thermotropic Monomers – Containing Phosphorus
Authors: Diana Serbezeanu, Ionela-Daniela Carja, Tachita Vlad-Bubulac, Sergiu Sova
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New phosphorus-containing monomers having methoxy end functional groups were prepared from methyl 4-hydroxybenzoate and two different dichlorides with phosphorus, namely phenyl phosphonic dichloride and phenyl dichlorophosphate. The structures of the monomers were confirmed by FTIR and NMR spectroscopy. The assignments for the 1H, 13C and 31P chemical shifts are based on 1D and 2D NMR homo- and heteronuclear correlations (H,H-COSY (Correlation Spectroscopy), H,C-HMQC (Heteronuclear Multiple Quantum Correlation and H,C-HMBC (Heteronuclear Multiple Bond Correlation)) and 31P-13C couplings. The monomers exhibited good solubility in common organic solvents. Dimethyl sulfoxide was to be a good solvent to grow crystals of considerable size which were investigated by X-ray analysis. One of these two new monomers presented thermotropic liquid crystalline behaviour, as revealed by differential scanning calorimetry (DSC), polarized light microscopy (PLM) and X-ray diffraction (XRD). The transition temperature from crystal to liquid crystalline state (K→LC) was 143°C and from the LC to isotropic state (LC→I) was 167°C. Upon heating, bis(4-(methoxycarbonyl)phenyl formed fine textures, difficult to be ascribed to smectic or nematic phases. Upon cooling from the isotropic state, bis(4-(methoxycarbonyl)phenyl exhibited a mosaic-type texture. X-ray diffraction measurements at small angles (SAXS) of bis(4-(methoxycarbonyl)phenyl showed two peaks at 1.8 Å and 3.5 Å, respectively suggesting organization at supramolecular level.Keywords: phosphorus-containing monomers, polarized light microscopy, structure investigation, thermotropic liquid crystalline properties
Procedia PDF Downloads 304713 Numerical Investigation of Nanofluid Based Thermosyphon System
Authors: Kiran Kumar K., Ramesh Babu Bejjam, Atul Najan
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A thermosyphon system is a heat transfer loop which operates on the basis of gravity and buoyancy forces. It guarantees a good reliability and low maintenance cost as it does not involve any mechanical pump. Therefore it can be used in many industrial applications such as refrigeration and air conditioning, electronic cooling, nuclear reactors, geothermal heat extraction, etc. But flow instabilities and loop configuration are the major problems in this system. Several previous researchers studied that stabilities can be suppressed by using nanofluids as loop fluid. In the present study a rectangular thermosyphon loop with end heat exchangers are considered for the study. This configuration is more appropriate for many practical applications such as solar water heater, geothermal heat extraction, etc. In the present work, steady-state analysis is carried out on thermosyphon loop with parallel flow coaxial heat exchangers at heat source and heat sink. In this loop nano fluid is considered as the loop fluid and water is considered as the external fluid in both hot and cold heat exchangers. For this analysis one-dimensional homogeneous model is developed. In this model, conservation equations like conservation of mass, momentum, energy are discretized using finite difference method. A computer code is written in MATLAB to simulate the flow in thermosyphon loop. A comparison in terms of heat transfer is made between water and nano fluid as working fluids in the loop.Keywords: heat exchanger, heat transfer, nanofluid, thermosyphon loop
Procedia PDF Downloads 478712 A Review on the Challenge and Need of Goat Semen Production and Artificial Insemination in Nepal
Authors: Pankaj K. Jha, Ajeet K. Jha, Pravin Mishra
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Goat raising is a popular livestock sub-commodity of mixed farming system in Nepal. Besides food and nutritional security, it has an important role in the economy of many peoples. Goat breeding through AI is commonly practiced worldwide. It is a very basic tool to speed up genetic improvement and increase productivity. For the goat genetic improvement program, the government of Nepal has imported some specialized exotic goat breeds and semen. Some progress has been made in the initiation of selective breeding within the local breeds and practice of AI with imported semen. Importance of AI in goats has drawn more attention among goat farmers. However, importing semen is not a permanent solution at national level; rather, it is more important to develop and establish its own frozen semen production technique. Semen quality and its relationship with fertility are said to be a major concern in animal production, hence accurate measurement of semen fertilizing potential is of great importance. The survivability of sperm cells depends on semen quality. Survivability of sperm cells is assessed through visual and microscopic evaluation of spermatozoal progressive motility and morphology. In Nepal, there is lack of scientific information on seminal attributes of buck semen, its dilution, cooling and freezing technique under management conditions of Nepal. Therefore, the objective of this review was to provide brief information about breeding system, semen production and artificial insemination in Nepalese goat.Keywords: artificial insemination, goat, Nepal, semen
Procedia PDF Downloads 214711 Performance Analysis of Air Conditioning System Working on the Vapour Compression Refrigeration Cycle under Magnetohydrodynamic Influence
Authors: Nikhil S. Mane, Mukund L. Harugade, Narayan V. Hargude, Vishal P. Patil
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The fluids exposed to magnetic field can enhance the convective heat transfer by inducing secondary convection currents due to Lorentz force. The use of magnetohydrodynamic (MHD) forces in power generation and mass transfer is increasing steadily but its application to enhance the convective currents in fluids needed to be explored. The enhancement in convective heat transfer using MHD forces can be employed in heat exchangers, cooling of molten metal, vapour compression refrigeration (VCR) systems etc. The effective increase in the convective heat transfer without any additional energy consumption will lead to the energy efficient heat exchanging devices. In this work, the effect of MHD forces on the performance of air conditioning system working on the VCR system is studied. The refrigerant in VCR system is exposed to the magnetic field which influenced the flow of refrigerant. The different intensities of magnets are used on the different liquid refrigerants and investigation on performance of split air conditioning system is done under different loading conditions. The results of this research work show that the application of magnet on refrigerant flow has positive influence on the coefficient of performance (COP) of split air conditioning system. It is also observed that with increasing intensity of magnetic force the COP of split air conditioning system also increases.Keywords: magnetohydrodynamics, heat transfer enhancement, VCRS, air conditioning, refrigeration
Procedia PDF Downloads 214710 Diagnosis of Alzheimer Diseases in Early Step Using Support Vector Machine (SVM)
Authors: Amira Ben Rabeh, Faouzi Benzarti, Hamid Amiri, Mouna Bouaziz
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Alzheimer is a disease that affects the brain. It causes degeneration of nerve cells (neurons) and in particular cells involved in memory and intellectual functions. Early diagnosis of Alzheimer Diseases (AD) raises ethical questions, since there is, at present, no cure to offer to patients and medicines from therapeutic trials appear to slow the progression of the disease as moderate, accompanying side effects sometimes severe. In this context, analysis of medical images became, for clinical applications, an essential tool because it provides effective assistance both at diagnosis therapeutic follow-up. Computer Assisted Diagnostic systems (CAD) is one of the possible solutions to efficiently manage these images. In our work; we proposed an application to detect Alzheimer’s diseases. For detecting the disease in early stage we used the three sections: frontal to extract the Hippocampus (H), Sagittal to analysis the Corpus Callosum (CC) and axial to work with the variation features of the Cortex(C). Our method of classification is based on Support Vector Machine (SVM). The proposed system yields a 90.66% accuracy in the early diagnosis of the AD.Keywords: Alzheimer Diseases (AD), Computer Assisted Diagnostic(CAD), hippocampus, Corpus Callosum (CC), cortex, Support Vector Machine (SVM)
Procedia PDF Downloads 387709 Wakala Buildings of Mamluk Era in Cairo, Egypt and Its Rating According to Rating Criteria of Leadership in Energy and Environmental Design V4
Authors: M. Fathy, I. Maarouf, S. El-Sayary
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Our buildings are responsible for around 50% of energy consumption and most of this consumption because of spaces design, low heat isolation building material and occupant presence and behavior in buildings beside non-efficient architectural treatments. It has been shown to have large impact on heating, cooling and ventilation demand, energy consumption of lighting and appliances, and building controls. This paper aims to focus on passive treatments in Wakala Buildings in Cairo and how far it meets the LEED Criteria as the LEED – Leadership in Energy and Environmental Design – considered the widest spread rating system in the world. By studying Wakala buildings in Cairo, there are a lot of environmental potentials in it in the field of passive treatments and energy efficiency that could be found in examples by surveying and analyzing Wakala buildings. Besides the environmental treatments through the natural materials and façade architectural treatments, there is a measuring phase to declare the efficiency of the Wakala building through temperature decline between outdoor and indoor the Wakala building. Also, measuring how far the indoor conditions matched the thermal comfort for occupants. After measuring the Wakala buildings, it is the role of applying the criteria of LEED rating system to find out how fare Wakala buildings meet the LEED rating system criteria. After all, the building technologies used in Wakala buildings in the field of passive design and caused that energy efficiency would be clear and what is needed for Wakala buildings to have a LEED Certification.Keywords: energy awareness, historical commercial buildings, LEED, Wakala buildings
Procedia PDF Downloads 207708 FELIX: 40 Hz Masked Flickering Light as a Potential Treatment of Major Depressive Disorder
Authors: Nikolas Aasheim, Laura Sakalauskaitė, Julie Dubois, Malina Ploug Larsen, Paul Michael Petersen, Marcus S. Carstensen, Marcus S. Carstensen, Mai Nguyen, Line Katrine Harder Clemmensen, Kamilla Miskowiak, Klaus Martiny
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Background: Major depressive disorder (MDD) is a debilitating condition that affects more than 300 million people worldwide and profoundly impacts well-being and health. Current treatments are based on a trial-and-error approach, and reliable biomarkers are needed for more informed and personalized treatment solutions. One potential biomarker is aberrant gamma-frequency (30-80 Hz) brainwaves, hypothesized to originate from deficiencies in the excitatory-inhibitory interaction between the pyramidal cells and interneurons. An imbalance within this interaction is described as a crucial pathological mechanism in various neuropsychiatric conditions, including MDD, and the modulation of this pathological interaction has been investigated as a potential target. A specific type of steady-state visually evoked potential (SSVEP) in the gamma frequency band, referred to as gamma entrainment using sensory stimuli (GENUS), particularly around the 40Hz spectrum, entrains large scale, fast-spiking PV+ interneurons, facilitating coordinated activity in key brain regions, reduced neuronal and synaptic loss, and enhanced synaptic stability and plasticity. GENUS has shown promise in improving sleep, offering neuroprotective effects in Alzheimer's disease (AD), and reducing pathological markers like Amyloid Beta and TAU proteins, as seen in animal models. In this study, we explore the antidepressant, cognitive, and electrophysiological effects of a novel, non-invasive brain stimulation (NIBS) approach utilizing a 40 Hz invisible spectral flicker to induce gamma activity in patients diagnosed with Major Depressive Disorder (MDD). This non-invasive targeted stimulation of lower gamma band activity (40 Hz) is designed to modulate neural circuits associated with mood and cognitive functions, providing a potential new therapeutic avenue for MDD. Methods and Design: 60 patients with a current diagnosis of a major depressive episode will be enrolled in a randomized, double-blinded, placebo-controlled trial. The active treatment group will receive 40 Hz invisible spectral flickering light stimulation while the control group will receive continuous light matched in colour temperature and brightness. Patients in both groups will get an hour of daily light treatment in their own homes and will attend four follow-up visits to assess depression severity measured by Hamilton Depression Rating Scale (HAM-D₆), several aspects of sleep, cognitive function, quality of life. Additionally, exploratory EEG is conducted to assess spectral changes throughout the protocol. The primary endpoint is the mean change from baseline to week 6 in depression severity (HAM-D₆ subset) between the groups. Current state of affairs/timeline: The FELIX study was initiated in the beginning of 2022, planning to reach stage of publication in December 2025. 21 participants have been enrolled in the protocol thus far, expecting to be finished with trials and recruitment by the end of 2024.Keywords: major depressive disorder, gamma, neurostimulation, EEG
Procedia PDF Downloads 19707 Development of Sustainable Farming Compartment with Treated Wastewater in Abu Dhabi
Authors: Jongwan Eun, Sam Helwany, Lakshyana K. C.
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The United Arab Emirates (UAE) is significantly dependent on desalinated water and groundwater resource, which is expensive and highly energy intensive. Despite the scarce water resource, stagnates only 54% of the recycled water was reused in 2012, and due to the lack of infrastructure to reuse the recycled water, the portion is expected to decrease with growing water usage. In this study, an “Oasis” complex comprised of Sustainable Farming Compartments (SFC) was proposed for reusing treated wastewater. The wastewater is used to decrease the ambient temperature of the SFC via an evaporative cooler. The SFC prototype was designed, built, and tested in an environmentally controlled laboratory and field site to evaluate the feasibility and effectiveness of the SFC subjected to various climatic conditions in Abu Dhabi. Based on the experimental results, the temperature drop achieved in the SFC in the laboratory and field site were5 ̊C from 22 ̊C and 7- 15 ̊C (from 33-45 ̊C to average 28 ̊C at relative humidity < 50%), respectively. An energy simulation using TRNSYS was performed to extend and validate the results obtained from the experiment. The results from the energy simulation and experiments show statistically close agreement. The total power consumption of the SFC system was approximately three and a half times lower than that of an electrical air conditioner. Therefore, by using treated wastewater, the SFC has a promising prospect to solve Abu Dhabi’s ecological concern related to desertification and wind erosion.Keywords: ecological farming system, energy simulation, evaporative cooling system, temperature, treated waste water, temperature
Procedia PDF Downloads 254706 The Analysis of Defects Prediction in Injection Molding
Authors: Mehdi Moayyedian, Kazem Abhary, Romeo Marian
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This paper presents an evaluation of a plastic defect in injection molding before it occurs in the process; it is known as the short shot defect. The evaluation of different parameters which affect the possibility of short shot defect is the aim of this paper. The analysis of short shot possibility is conducted via SolidWorks Plastics and Taguchi method to determine the most significant parameters. Finite Element Method (FEM) is employed to analyze two circular flat polypropylene plates of 1 mm thickness. Filling time, part cooling time, pressure holding time, melt temperature and gate type are chosen as process and geometric parameters, respectively. A methodology is presented herein to predict the possibility of the short-shot occurrence. The analysis determined melt temperature is the most influential parameter affecting the possibility of short shot defect with a contribution of 74.25%, and filling time with a contribution of 22%, followed by gate type with a contribution of 3.69%. It was also determined the optimum level of each parameter leading to a reduction in the possibility of short shot are gate type at level 1, filling time at level 3 and melt temperature at level 3. Finally, the most significant parameters affecting the possibility of short shot were determined to be melt temperature, filling time, and gate type.Keywords: injection molding, plastic defects, short shot, Taguchi method
Procedia PDF Downloads 219705 Optic Nerve Sheath Measurement in Children with Head Trauma
Authors: Sabiha Sahin, Kursad Bora Carman, Coskun Yarar
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Introduction: Measuring the diameter of the optic nerve sheath is a noninvasive and easy to use imaging technique to predict intracranial pressure in children and adults. The aim was to measure the diameter of the optic nerve sheath in pediatric head trauma. Methods: The study group consisted of 40 children with healthy and 40 patients with head trauma. Transorbital sonographic measurement of the optic nerve sheath diameter was performed. Conclusion: The mean diameters of the optic nerve sheath of right and left eyes were 0.408 ± 0.064 mm and 0.417 ± 0.065 mm, respectively, in the trauma group. These results were higher in patients than in control group. There was a negative correlation between optic nerve sheath diameters and Glasgow Coma Scales in patients with head trauma (p < 0.05). There was a positive correlation between optic nerve sheath diameters and positive CT findings, systolic blood pressure in patients with head trauma. The clinical status of the patients at admission, blood pH and lactate level were related to the optic nerve sheath diameter. Conclusion: Measuring the diameter of the optic nerve sheath is not an invasive technique and can be easily used to predict increased intracranial pressure and to prevent secondary brain injury.Keywords: head trauma, intracranial pressure, optic nerve, sonography
Procedia PDF Downloads 163704 Quality Evaluation of Treated Ballast Seawater for Potential Reuse
Authors: Siti Nur Muhamad, Mohamad Abu Ubaidah Amir, Adenen Shuhada Abdul Aziz, Siti Sarah Mohd Isnan, Ainul Husna Abdul Rahman, Nur Afiqah Rosly, Roshamida Abd Jamil
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The International Convention for the Control and Management of Ships’ Ballast Water and Sediments (BWM Convention) will commencing on 8 September 2017 after ratified by 51 States in September 2016. However, there is no value recovered for the treated ballast water as it simply discharged during de-ballasting. In order to evaluate value creation of treated ballast water, three seawater applications which are seawater toilet flushing, cooling tower and desalination was studied and compared with treated ballast seawater. An exploratory study was conducted in Singapore as a case study as this country is facing water scarcity issues and a busy port in the world which received more than 28 billion m3 of ballast water in 2015. Surprisingly the treatment technology between seawater toilet flushing and ballast water management has similarity as both applications use screening and disinfection process and quality standard and analysis between treated ballast water with seawater applications found that seawater toilet flushing have the same quality parameter with treated ballast water. Thus, the treated ballast water can replace the raw seawater for seawater desalination. As such, with reduction of cost for screen unit, desalination water can exceed water production by NEWater in Singapore as the cost can recover the energy needed for desalination. It can conclude that treated ballast water has high recovery value and can be reused in seawater application.Keywords: ballast water treatment, desalination, BWM convention, ballast water management
Procedia PDF Downloads 383703 Energy Efficient Plant Design Approaches: Case Study of the Sample Building of the Energy Efficiency Training Facilities
Authors: Idil Kanter Otcu
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Nowadays, due to the growing problems of energy supply and the drastic reduction of natural non-renewable resources, the development of new applications in the energy sector and steps towards greater efficiency in energy consumption are required. Since buildings account for a large share of energy consumption, increasing the structural density of buildings causes an increase in energy consumption. This increase in energy consumption means that energy efficiency approaches to building design and the integration of new systems using emerging technologies become necessary in order to curb this consumption. As new systems for productive usage of generated energy are developed, buildings that require less energy to operate, with rational use of resources, need to be developed. One solution for reducing the energy requirements of buildings is through landscape planning, design and application. Requirements such as heating, cooling and lighting can be met with lower energy consumption through planting design, which can help to achieve more efficient and rational use of resources. Within this context, rather than a planting design which considers only the ecological and aesthetic features of plants, these considerations should also extend to spatial organization whereby the relationship between the site and open spaces in the context of climatic elements and planting designs are taken into account. In this way, the planting design can serve an additional purpose. In this study, a landscape design which takes into consideration location, local climate morphology and solar angle will be illustrated on a sample building project.Keywords: energy efficiency, landscape design, plant design, xeriscape landscape
Procedia PDF Downloads 263702 Influences of Thermal Treatments on Dielectric Behaviors of Carbon Nanotubes-BaTiO₃ Hybrids Reinforced Polyvinylidene Fluoride Composites
Authors: Benhui Fan, Fahmi Bedoui, Jinbo Bai
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Incorporated carbon nanotube-BaTiO₃ hybrids (H-CNT-BT) with core-shell structure, a better dispersion of CNTs can be achieved in a semi-crystalline polymeric matrix, polyvinylidene fluoride (PVDF). Carried by BT particles, CNTs are easy to mutually connect which helps to obtain an extremely low percolation threshold (fc). After thermal treatments, the dielectric constants (ε’) of samples further increase which depends on the conditions of thermal treatments such as annealing temperatures, annealing durations and cooling ways. Thus, in order to study more comprehensively about the influence of thermal treatments on composite’s dielectric behaviors, in situ synchrotron X-ray is used to detect re-crystalline behavior of PVDF. Results of wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) show that after the thermal treatment, the content of β polymorph (the polymorph with the highest ε’ among all the polymorphs of PVDF’s crystalline structure) has increased nearly double times at the interfacial region of CNT-PVDF, and the thickness of amorphous layers (La) in PVDF’s long periods (Lp) has shrunk around 10 Å. The evolution of CNT’s network possibly occurs in the procedure of La shrinkage, where the strong interfacial polarization may be aroused and increases ε’ at low frequency. Moreover, an increase in the thickness of crystalline lamella may also arouse more orientational polarization and improve ε’ at high frequency.Keywords: dielectric properties, thermal treatments, carbon nanotubes, crystalline structure
Procedia PDF Downloads 325701 Determination of Physicochemical Properties, Bioaccessibility of Phenolics and Antioxidant Capacity of Mineral Enriched Linden Herbal Tea Beverage
Authors: Senem Suna, Canan Ece Tamer, Ömer Utku Çopur
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In this research, dried linden (Tilia argentea) leaves and blossoms were used as a raw material for mineral enriched herbal tea beverage production. For this aim, %1 dried linden was infused with boiling water (100 °C) for 5 minutes. After cooling, sucrose, citric acid, ascorbic acid, natural lemon flavor and natural mineral water were added. Beverage samples were plate filtered, filled into 200-mL glass bottles, capped then pasteurized at 98 °C for 15 minutes. Water soluble dry matter, titratable acidity, ascorbic acid, pH, minerals (Fe, Ca, Mg, K, Na), color (L*, a*, b*), turbidity, bioaccessible phenolics and antioxidant capacity were analyzed. Water soluble dry matter, titratable acidity, and ascorbic were determined as 7.66±0.28 g/100 g, 0.13±0.00 g/100 mL, and 19.42±0.62 mg/100 mL, respectively. pH was measured as 3.69. Fe, Ca, Mg, K and Na contents of the beverage were determined as 0.12±0.00, 115.48±0.05, 34.72±0.14, 48.67±0.43 and 85.72±1.01 mg/L, respectively. Color was measured as 13.63±0.05, -4.33±0.05, and 3.06±0.05 for L*, a*, and b* values. Turbidity was determined as 0.69±0.07 NTU. Bioaccessible phenolics were determined as 312.82±5.91 mg GAE/100 mL. Antioxidant capacities of chemical (MetOH:H2O:HCl) and physiological extracts (in vitro digestive enzymatic extraction) with DPPH (27.59±0.53 and 0.17±0.02 μmol trolox/mL), FRAP (21.01±0.97 and 13.27±0.19 μmol trolox/mL) and CUPRAC (44.71±9.42 and 2.80±0.64 μmol trolox/mL) methods were also evaluated. As a result, enrichment with natural mineral water was proposed for the development of functional and nutritional values together with a good potential for commercialization.Keywords: linden, herbal tea beverage, bioaccessibility, antioxidant capacity
Procedia PDF Downloads 177700 Effect of Convective Dryness Combined with Osmotic Dehydration, Blanching, Microwave and Ultrasonic Treatment on Bioactive Compounds and Rehydration Capacity of Dried Plums
Authors: Elena Corina Popescu, Magda Gabriela Bratu
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Increasing interest in keeping bioactive compounds (anthocyanins, vitamin C) and dried fruit quality has motivated the researchers to investigate new combined drying technologies. The aim of this study was to evaluate the effects of convective dryness combined with osmotic dehydration, blanching, microwave treatment and ultrasonic treatment on the quality of dried plums. Osmotic dehydration was achieved by maintaining plums for 1 h in sucrose solution (300Brix). For microwave treatment, the plums were kept at 400 W for 80 sec. For ultrasonic treatment, plums were immersed in distilled water and sonicated for 30 minutes at 40 kHz and 200 W. The blanching consists of immersing plums in hot water at 90°C for 20 seconds and cooling them rapidly. Conventional drying was carried out at 70°C for 630 minutes. Drying curves, drying rate, anthocyanin and vitamin C stability, acidity variation (expressed as malic acid), reducing sugar content, and rehydration capacity of dried plums were analyzed. Blanching led to the largest amount of evaporated water. Blanched plums have had 13.36% less water than sonicated ones. The lowest anthocyanal loss of 34.5% was obtained in osmotically dehydrated plums, and 2.93% vitamin C is found in the plums sonicated. There were no significant differences in regards acidity and reducing sugar. The plums blanched before drying have had a high capacity of rehydration.Keywords: anthocyanin, dried plums, pretreatments, vitamin C
Procedia PDF Downloads 239699 Effects of Surface Roughness on a Unimorph Piezoelectric Micro-Electro-Mechanical Systems Vibrational Energy Harvester Using Finite Element Method Modeling
Authors: Jean Marriz M. Manzano, Marc D. Rosales, Magdaleno R. Vasquez Jr., Maria Theresa G. De Leon
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This paper discusses the effects of surface roughness on a cantilever beam vibrational energy harvester. A silicon sample was fabricated using MEMS fabrication processes. When etching silicon using deep reactive ion etching (DRIE) at large etch depths, rougher surfaces are observed as a result of increased response in process pressure, amount of coil power and increased helium backside cooling readings. To account for the effects of surface roughness on the characteristics of the cantilever beam, finite element method (FEM) modeling was performed using actual roughness data from fabricated samples. It was found that when etching about 550um of silicon, root mean square roughness parameter, Sq, varies by 1 to 3 um (at 100um thick) across a 6-inch wafer. Given this Sq variation, FEM simulations predict an 8 to148 Hz shift in the resonant frequency while having no significant effect on the output power. The significant shift in the resonant frequency implies that careful consideration of surface roughness from fabrication processes must be done when designing energy harvesters.Keywords: deep reactive ion etching, finite element method, microelectromechanical systems, multiphysics analysis, surface roughness, vibrational energy harvester
Procedia PDF Downloads 124698 Performance Evaluation of Adsorption Refrigerating Systems
Authors: Nadia Allouache, Omar Rahli
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Many promising technologies have been developed to harness the sun's energy. These technologies help in economizing energy and environmental protection. The solar refrigerating systems are one of these important technologies. In addition to environmental benefits and energy saving, adsorption refrigerating systems have many advantages such as lack of moving parts, simplicity of construction and low operating costs. The work aimed to establish the main factors that affect the performances of an adsorption refrigerating system using different geometries of adsorbers and different adsorbent-adsorbate pairs. The numerical modeling of the heat and mass transfer in the system, using various working pairs, such as: activated carbon-ammonia, calcium chlorid-ammonia, activated carbon fiber- methanol and activated carbon AC35-methanol, show that the adsorber design can influence the system performances; The thermal performances of system are better in the annular configuration case. An optimal value of generating temperature is observed in annular adsorber case for which the thermal performance of the cooling system is maximal. While in the plate adsorber, above a certain value of generating temperature, the performance of the system remains almost constant. The environmental conditions such as solar radiation and pressure have a great influence in the system efficiency, and the choice of the working pair depends on the environmental conditions and the geometry of the adsorber.Keywords: adsorber geometry, numerical modeling, optimal environmental conditions, working pairs.
Procedia PDF Downloads 82697 Passive Retrofitting Strategies for Windows in Hot and Humid Climate Vijayawada
Authors: Monica Anumula
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Nowadays human beings attain comfort zone artificially for heating, cooling and lighting the spaces they live, and their main importance is given to aesthetics of building and they are not designed to protect themselves from climate. They depend on artificial sources of energy resulting in energy wastage. In order to reduce the amount of energy being spent in the construction industry and Energy Package goals by 2020, new ways of constructing houses is required. The larger part of energy consumption of a building is directly related to architectural aspects hence nature has to be integrated into the building design to attain comfort zone and reduce the dependency on artificial source of energy. The research is to develop bioclimatic design strategies and techniques for the walls and roofs of Vijayawada houses. Study and analysis of design strategies and techniques of various cases like Kerala, Mangalore etc. for similar kind of climate is examined in this paper. Understanding the vernacular architecture and modern techniques of that various cases and implementing in the housing of Vijayawada not only decreases energy consumption but also enhances socio cultural values of Vijayawada. This study focuses on the comparison of vernacular techniques and modern building bio climatic strategies to attain thermal comfort and energy reduction in hot and humid climate. This research provides further thinking of new strategies which include both vernacular and modern bioclimatic techniques.Keywords: bioclimatic design, energy consumption, hot and humid climates, thermal comfort
Procedia PDF Downloads 180696 CNS Cryptococcoma in an Immunocompetent Adult from a Low Resource Setting: A Case Report
Authors: Ssembatya Joseph Mary
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Introduction: Cryptococcal infection in the Central Nervous System (CNS) is frequently seen in human immunodeficiency virus (HIV) patients and others with low immunity as an opportunistic fungal infection. However, CNS cryptococcal granuloma (cryptococcoma) in immunocompetent patients is rare. We present a case of CNS cryptococcoma in an immunocompetent patient and review the literature to illustrate the diagnosis and treatment of such lesions. Case presentation: A 62-year-old, HIV-negative, immunocompetent female patient with no known chronic illness presented with 5 months history of a progressive headache associated with on and off episodic generalized tonic-clonic convulsions. She had been to several hospitals before she was referred to our center with a diagnosis of a brain tumor. Before referral and despite a negative CSF analysis result, she had received treatment for bacterial meningitis with no success. At Mbarara Regional Referral Hospital (MRRH), she had surgery with an excision biopsy which showed features consistent with cryptococcosis on histology. The patient had a successful adjuvant treatment with antifungal drugs following surgery. Conclusion: The diagnosis of a parasitic CNS infection, particularly cryptococcal infection mimicking neoplastic lesions in an immunocompetent patient, was unusual. Surgical management of such lesions from different reports has a bad outcome and management remains totally conservative.Keywords: Cryptococcal meningitis, immunocompetent patient, Uganda, low resource setting
Procedia PDF Downloads 89695 Design, Construction, Technical and Economic Evaluation of a Solar Water Desalination Device with Two Heat Exchangers and a Photovoltaic System
Authors: Mehdi Bakhtiarzadeh, Reza Efatnejad, Kambiz Rezapour Rezapour
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Due to the limited resources of fossil fuels and their harmful effects on the environment and human health, research on renewable energy applications in industrial and scientific communities has become particularly important. Only one percent of freshwater resources are available for use in the domestic, agricultural, and industrial sectors. On the other hand, the rapid growth of industry and the increase of population in most countries of the world, including Iran, have led to an increase in demand for freshwater. Among renewable energies, there is the potential of solar energy in Iran. As a result, solar distillation systems can be used as a solution to supply fresh water in remote rural areas. Therefore, in the present study, a solar water desalination device was designed and manufactured using two heat exchangers and a photovoltaic system. Its evaluation was done during September and October of 2020. During the evaluation of the device, environmental variables such as total solar radiation, ambient temperature and cooling tower temperature were recorded at intervals of one hour from 9 am to 5 pm. The effect of these variables on solar concentrator performance, heat exchanger, and daily freshwater production was evaluated. The results showed that using two heat exchangers and a photovoltaic system has led to the daily production of 5 liters of fresh water and 46% economic efficiency.Keywords: solar water desalination, heat exchanger, photovoltaic system, technical and economic evaluation
Procedia PDF Downloads 173694 Designing a Patient Monitoring System Using Cloud and Semantic Web Technologies
Authors: Chryssa Thermolia, Ekaterini S. Bei, Stelios Sotiriadis, Kostas Stravoskoufos, Euripides G. M. Petrakis
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Moving into a new era of healthcare, new tools and devices are developed to extend and improve health services, such as remote patient monitoring and risk prevention. In this concept, Internet of Things (IoT) and Cloud Computing present great advantages by providing remote and efficient services, as well as cooperation between patients, clinicians, researchers and other health professionals. This paper focuses on patients suffering from bipolar disorder, a brain disorder that belongs to a group of conditions called effective disorders, which is characterized by great mood swings.We exploit the advantages of Semantic Web and Cloud Technologies to develop a patient monitoring system to support clinicians. Based on intelligently filtering of evidence-knowledge and individual-specific information we aim to provide treatment notifications and recommended function tests at appropriate times or concluding into alerts for serious mood changes and patient’s non-response to treatment. We propose an architecture, as the back-end part of a cloud platform for IoT, intertwining intelligence devices with patients’ daily routine and clinicians’ support.Keywords: bipolar disorder, intelligent systems patient monitoring, semantic web technologies, healthcare
Procedia PDF Downloads 512693 The Role of College Teachers’ in Identifying Attention Deficit Hyperactivity Disorder in Students
Authors: Hargunjeet Shergill, Palwinder Singh
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The present paper analyzes the lack of teachers' awareness and knowledge regarding the Attention Deficit Hyperactivity Disorder in the college students. Attention deficit hyperactivity disorder causes individuals to consistently display extreme inattention, impulsivity and in many cases hyperactivity as a result of the physiological differences of the brain. Teachers have a formative influence on their students and can play a key role in identifying and supporting students with Attention Deficit/Hyperactivity Disorder (ADHD). Despite the pervasiveness and salience of this disorder, educators at college continue to labor under a number of misconceptions about the nature of ADHD. In order to fulfill this important role, it is imperative for teachers to have explicit knowledge about this disorder. ADHD in college students remains the most under-recognized and undertreated mental health condition. The overall aim of this study is to investigate teachers’ knowledge and misconceptions of ADHD with a particular focus on recognition, assessment and management of ADHD in adult college students. It designed to assess the college teachers' knowledge, opinions, and experience related to the diagnosis of attention-deficit/hyperactivity disorder (ADHD) and by maintaining open lines of communication with the students and understanding some key elements that can affect students’ overall growth and ability. The discussion focuses on the value of the role of teachers and their relationship with each college student dealing with ADHD.Keywords: attention deficit hyperactivity disorder, development of ADHD, diagnostic criteria, role of teachers
Procedia PDF Downloads 218692 A Framework to Assess the Maturity of Customer Involvement in the Service Design of Product-Service Systems
Authors: Taghreed Abu-Salim
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This paper develops and investigates a framework for the assessment of customer involvement in the service design process of result oriented product-service systems in order to improve the service offering in a business to business (B2B) context. The framework comprises five main criteria and fifteen sub-criteria that contribute to customer involvement in a hierarchy using a maturity grid to highlight the strengths and weaknesses for each criterion. To develop the customer involvement framework, an extensive literature review related to service design, result oriented product-service system (PSS) and customer involvement in service design was carried out. Key factors that significantly influence customer involvement from industry and literature were identified to develop an initial framework. This framework was tested in six companies from four different sectors of industry: district cooling, medical equipment, transportation and oil storage. Validation of the framework was carried out using expert opinions and industrial case studies. A major contribution of the developed framework includes a hierarchy of appropriate criteria for assessing customer involvement in the service design process within results oriented PSS; the definition of four maturity levels which are suitable to describe the whole spectrum of customer involvement in the service design process; and finally, The paper concludes by enabling service providers to: take proactive decisions; screen and evaluate new services; improve perceived service quality; and provide barriers against imitation.Keywords: customer involvement, maturity grid, new service development, result oriented product-service system, service design
Procedia PDF Downloads 536691 Increasing of Gain in Unstable Thin Disk Resonator
Authors: M. Asl. Dehghan, M. H. Daemi, S. Radmard, S. H. Nabavi
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Thin disk lasers are engineered for efficient thermal cooling and exhibit superior performance for this task. However the disk thickness and large pumped area make the use of this gain format in a resonator difficult when constructing a single-mode laser. Choosing an unstable resonator design is beneficial for this purpose. On the other hand, the low gain medium restricts the application of unstable resonators to low magnifications and therefore to a poor beam quality. A promising idea to enable the application of unstable resonators to wide aperture, low gain lasers is to couple a fraction of the out coupled radiation back into the resonator. The output coupling gets dependent on the ratio of the back reflection and can be adjusted independently from the magnification. The excitation of the converging wave can be done by the use of an external reflector. The resonator performance is numerically predicted. First of all the threshold condition of linear, V and 2V shape resonator is investigated. Results show that the maximum magnification is 1.066 that is very low for high quality purposes. Inserting an additional reflector covers the low gain. The reflectivity and the related magnification of a 350 micron Yb:YAG disk are calculated. The theoretical model was based on the coupled Kirchhoff integrals and solved numerically by the Fox and Li algorithm. Results show that with back reflection mechanism in combination with increasing the number of beam incidents on disk, high gain and high magnification can occur.Keywords: unstable resonators, thin disk lasers, gain, external reflector
Procedia PDF Downloads 416690 A Portable Cognitive Tool for Engagement Level and Activity Identification
Authors: Terry Teo, Sun Woh Lye, Yufei Li, Zainuddin Zakaria
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Wearable devices such as Electroencephalography (EEG) hold immense potential in the monitoring and assessment of a person’s task engagement. This is especially so in remote or online sites. Research into its use in measuring an individual's cognitive state while performing task activities is therefore expected to increase. Despite the growing number of EEG research into brain functioning activities of a person, key challenges remain in adopting EEG for real-time operations. These include limited portability, long preparation time, high number of channel dimensionality, intrusiveness, as well as level of accuracy in acquiring neurological data. This paper proposes an approach using a 4-6 EEG channels to determine the cognitive states of a subject when undertaking a set of passive and active monitoring tasks of a subject. Air traffic controller (ATC) dynamic-tasks are used as a proxy. The work found that when using the channel reduction and identifier algorithm, good trend adherence of 89.1% can be obtained between a commercially available BCI 14 channel Emotiv EPOC+ EEG headset and that of a carefully selected set of reduced 4-6 channels. The approach can also identify different levels of engagement activities ranging from general monitoring ad hoc and repeated active monitoring activities involving information search, extraction, and memory activities.Keywords: assessment, neurophysiology, monitoring, EEG
Procedia PDF Downloads 78689 Cross Line of Causality in Childhood Stuttering between Psychology and Neurolinguistics: Systematic Literature Review and Meta-Analysis
Authors: Sadeq Al Yaari, Muhammad Alkhunayn, Ayman Al Yaari, Montaha Al Yaari, Aayah Al Yaari, Adham Al Yaari, Sajedah Al Yaari, Fatehi Eissa
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Stuttering is a multidimensional disorder that is influenced by different factors. As a result of their un-understanding of the genuine reasons behind stuttering, psychiatrists and Speech and Language Pathologists/Therapists (SLP/Ts) are often unfamiliar with the psychoneurolinguistic characteristics, support needs, and the disability measurement impacting requested rehabilitation of the stuttering population. PubMed, PsycInfo, Web of Science, Scopus, and Google scholar searches, in addition to some unpublished literature, were conducted in this Systematic Literature Review and Meta-analysis (SLR and Meta-analysis) to identify whether stuttering is caused by psychological or neurological reasons. The study concluded that psychological, not neurolinguistic factors were identified as most significant for the causality of childhood stuttering. Stutterers have intact language skills, but impaired ability more to communicate with others than to form letters in the brain or to articulate them. The study recommends research in the future that sheds light on the adult stuttering population often left out of the focus of diagnosis and in need of further exploration vis-a-vis issues they encounter, as well as the possible ways to deal with them psychoneurolinguistically.Keywords: causality, childhood stuttering, psychology, neurolinguistics, systematic literature review, meta-analysis
Procedia PDF Downloads 55688 Multi-Objective Optimization of a Solar-Powered Triple-Effect Absorption Chiller for Air-Conditioning Applications
Authors: Ali Shirazi, Robert A. Taylor, Stephen D. White, Graham L. Morrison
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In this paper, a detailed simulation model of a solar-powered triple-effect LiBr–H2O absorption chiller is developed to supply both cooling and heating demand of a large-scale building, aiming to reduce the fossil fuel consumption and greenhouse gas emissions in building sector. TRNSYS 17 is used to simulate the performance of the system over a typical year. A combined energetic-economic-environmental analysis is conducted to determine the system annual primary energy consumption and the total cost, which are considered as two conflicting objectives. A multi-objective optimization of the system is performed using a genetic algorithm to minimize these objectives simultaneously. The optimization results show that the final optimal design of the proposed plant has a solar fraction of 72% and leads to an annual primary energy saving of 0.69 GWh and annual CO2 emissions reduction of ~166 tonnes, as compared to a conventional HVAC system. The economics of this design, however, is not appealing without public funding, which is often the case for many renewable energy systems. The results show that a good funding policy is required in order for these technologies to achieve satisfactory payback periods within the lifetime of the plant.Keywords: economic, environmental, multi-objective optimization, solar air-conditioning, triple-effect absorption chiller
Procedia PDF Downloads 246687 Anti-Proliferative Effect of Chanterelle (Cantharellus) Mushroom Extracts on Glioblastoma Multiforme Cell Line U87MG
Authors: Justyna Moskwa, Patryk Nowakowski, Sylwia K. Naliwajko, Renata Markiewicz-Zukowska, Krystyna Gromkowska-Kepka, Anna Puscion-Jakubik, Konrad Mielcarek, Maria H. Borawska
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For centuries, mushrooms have been used in folk medicine; however, knowledge of the composition and properties of fungi comes from the last twenty years. Mushrooms show antibacterial, antioxidant, antitumor and immune-stimulating properties; however, there is a lack of reports, on anticancer treatment of brain gliomas. The aim of this study was to examine influence of Chanterelle mushroom (Cantharellus Adans. ex Fr.) ethanolic (CHE) and water (CHW) extracts, on glioblastoma multiforme cell line (U87MG). Anti-proliferative activity of CHE and CHW in concentration (50-1000 µg/mL) was determined by a cytotoxicity test and DNA binding by [³H]-thymidine incorporation after 24, 48 and 72h of incubation with U87MG glioblastoma cell line. The statistical analysis was performed using Statistica v. 13.0 software. Significant differences were assumed for p < 0.05. We examined that CHE extracts in all the tested concentrations (50, 100, 250, 500, 1000 µg/mL) after all hours of incubation significantly decreased cell viability (p < 0.05) on U87MG cell line, which was confirmed by the significant (p < 0.05) reduction of DNA synthesis. Our results suggest that only CHE extract a cytotoxic and anti-proliferation activities on U87MG cell line.Keywords: anticancer, food, glioblastoma, mushroom
Procedia PDF Downloads 164686 Impacts of the Mineralogical Composition on the Petrophysical Behavior of the Amygdaloidal and Vesicular Basalts of Wadi Wizr, Eastern Desert, Egypt
Authors: Nadia A. Wassif, Bassem S. Nabawy
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This paper gives an account of the petrophysical characteristics and the petrographical descriptions of Tertiary vesicular and amygdaloidal olivine basalt samples from Wadi Wizr in the central Eastern Desert of Egypt. The petrographical studies indicated that the studied vesicular basalt is rich in calcic-plagioclase, augite and olivine in addition to numerous amounts of fine opaque minerals and vesicules filled with carbonate and quartz amygdales. The degree of oxidation and alteration of magnetite and ilmenite were discussed in details. Petrophysically, the studied samples can be grouped into two main groups; the first group of samples is amygdaloidal basalt as the second group is vesicular. The vesicular group (the permeable one) is characterized by fair to very good porosity ‘Φ’, good to very good permeability ‘k’, very low true formation factor ‘F’ and micro to ultra micropores. On the other hand, the amygdaloidal basalt group (impermeable group) is characterized by very low storage capacity properties, fair porosity, negligible permeability, medium to high true formation factor and ultra micorpores. It has been found that; the petrophysical behavior is strongly dependent on the degree of oxidation and alteration; and in particular on the rate of cooling and oxidation of the ore minerals which caused filling in the primarily produced vesicules by low temperature secondary minerals.Keywords: vesicular, amygdaloidal, basalt, petrophysics, Egypt
Procedia PDF Downloads 363685 Preparation and Characterization of Water-in-Oil Nanoemulsion of 5-Fluorouracil to Enhance Skin Permeation for Treatment of Skin Diseases.
Authors: P. S. Rajinikanth, Shobana Mariappan, Jestin Chellian
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The objective of the study was to prepare and characterize a water-in-oil nano emulsion of 5-Fluorouracil (5FU) to enhance the skin penetration. The present study describes a nano emulsion of 5FU using Capyrol PGMC, Transcutol HP and PEG 400 as oil, surfactant and co-surfactant, respectively. The optimized formulations were further evaluated for heating cooling cycle, centrifugation studies, freeze thaw cycling, particle size distribution and zeta potential in order to confirm the stability of the optimized nano emulsions. The in-vitro characterization results showed that the droplets of prepared formulation were ~100 nm with ± 15 zeta potential. In vitro skin permeation studies was conducted in albino mice skin. Significant increase in permeability parameters was also observed in nano emulsion formulations (P<0.05). The steady-state flux (Jss), enhancement ration and permeability coefficient (Kp) for optimized nano emulsion formulation (FU2, FU1, 1:1 S mix were found to be 24.21 ±2.45 μg/cm2/h, 3.28±0.87 & 19.52±1.87 cm/h, respectively), which were significant compared with conventional gel. The in vitro and in vivo skin deposition studies in rat indicated that the amount of drug deposited from the nano emulsion (292.45 µg/cm2) in skin was significant (P<0.05) an increased as compared to a conventional 5FU gel (121.42 µg/cm2). The skin irritation study using rat skin showed that the mean irritation index of the nano emulsion reduced significantly (P<0.05) as compared with conventional gel contain 1% 5FU. The results from this study suggest that a water-in-oil nano emulsion could be safely used to promote skin penetration of 5FU following topical application.Keywords: nano emulsion, controlled release, 5 fluorouracil, skin penetration, skin irritation
Procedia PDF Downloads 504