Search results for: double lungs

Authors: M. Naimur Rahman, Mohammad Tariqul Islam, Mandeep Singh Jit Singh, Norbahiah Misran

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This paper presents the architecture and exploration of a compact, circulated double Psi-shaped microstrip patch antenna for Ku-band satellite applications. The antenna is composed of the double Psi-shaped patch in opposite focus which is circulated with a ring. The antenna size is 24 mm × 18 mm and the prototype is imprinted on Rogers RT/duroid 5880 materials with the depth of 1.57 mm. The substrate has a relative permittivity of 2.2 and the dielectric constant of 0.0009. The excitation is supplied through a 50Ω microstrip line. The performance of the presented antenna has been simulated and verified with the High-Frequency Structural Simulator (HFSS). The results depict that the antenna covers the frequency spectrum 14.6 - 17.4 GHz (Ku-band) with 10 dB return loss. The antenna has a 4.40 dBi maximum gain with stable radiation patterns throughout the operating band which makes the proposed antenna compatible for the satellite application in Ku-band.

Keywords: Ku-band antenna, microstrip antenna, psi-shaped antenna, satellite applications

Procedia PDF Downloads 278

Authors: Belloui Bouzid

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In this paper, broadband design of erbium doped fiber amplifier (EDFA) is demonstrated and proved experimentally. High and broad gain is covered in C and L bands. The used technique combines, in one configuration, two double passes with split band structure for the amplification of two traveled signals one for the C band and the other for L band. This new topology is to investigate the trends of high gain and wide amplification at different status of pumping power, input wavelength, and input signal power. The presented paper is to explore the performance of EDFA gain using what it can be called double pass double branch wide band amplification configuration. The obtained results show high gain and wide broadening range of 44.24 dB and 80 nm amplification respectively.

Keywords: erbium doped fiber amplifier, erbium doped fiber laser, optical amplification, fiber laser

Procedia PDF Downloads 233

Authors: Sertac Arslan, Guven Guney, Ayse Ipek Akyuz Unsal, Emre Demir, Buket Demirci

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Purpose: There is little histologic data concerning effects of nasal decongestants on the respiratory tract. We aimed to put forth the effects of nasal decongestants on the trachea and lower airways of rats. Materials and Methods: Four to six months old 60 male rats were randomly categorized into 6 groups. Experimental drugs were applied to the same nostril of rats twice daily for 8 weeks (Xylometazolin, Benzalkolyum, EDTA, Sorbitol and combined drug solutions). We applied normal saline solution (NaCl %0.9) for the control group. In the end, trachea and both lungs were dissected and kept in formaldehyde for histopathologic evaluation. Results: Inflammation and bronchial edema were most common findings. While all rats in sorbitol group had increased numbers of type 2 pneumocytes; 80% of BAC group had increased numbers of type 2 pneumocytes. Spillover of tracheal epithelium was seen mostly in sorbitol, EDTA and combined drug groups (60%, 87.5%, 50% respectively). Bronchial smooth muscle hypertrophy was seen mostly in BAC and EDTA group (70%, 62.5% respectively). The number of goblet cells showed the significant difference between control-combined drug (p=0.025) and control-BAC (p=0.001) groups. Conclusions: Nasal decongestants can cause permanent changes at lower respiratory tract in addition to changes in upper respiratory tract.

Keywords: decongestive agents, xylometazoline, lung, trachea

Procedia PDF Downloads 151

Authors: Husham Bayazed

Abstract:

The infant immune system has a reputation for being weak and underdeveloped when compared to the adult immune system, but the comparison isn’t quite fair. At the start, as the COVID-19 pandemic drags on and evolves, many Pediatricians and kids' parents have been left with renewed questions about the consequences and sequel of infection on children and the steps to be taken if their child, has the symptoms of COVID-19 or tests positive. Recent Findings: Literature reviews and recent studies revealed that children are better than adults at controlling SARS-CoV-2. There was conflicting evidence on age-related differences in ACE2 expression in the nose and lungs. But scientists who measured the ‘viral load’ in children's upper airways have seen no clear difference between children and adults. Moreover, the hypothesis is that kids might be more exposed to other coronaviruses common cold with a production of ready protective antibodies to lock on to the pandemic coronavirus. But the evidence suggests that adults also have this immunity too. Strikingly, these ‘cross-reactive’ antibodies don’t offer any special protection. Summary: One of the few silver linings of the Covid-19 pandemic is that children are relatively spared. The kid's Innate Immunity is hardly the whole story, the innate immune response against SARS-CoV-2 infection is early initiative calm with low immunological tone to prevent an overactive immunity and with rapidly repair damage to the lungs in contrast to stormy waves in adults. Therefore, Kids are at much lower risk of Covid-19 infection and they are still winning the battle against Covid-19 with their innate immunity.

Keywords: kids, Covid-19, immunity, ACT2

Procedia PDF Downloads 72

Authors: Jong-Yeon Kim, Kwang-Bok Shin, Tae-Hwan Ko

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The purpose of this paper is to suggest a weight-reduction design method for the aluminum extrusion carbody structure of a double deck high-speed train using size optimization method. The size optimization method was used to optimize thicknesses of skin and rib of the aluminum extrusion for the carbody structure. Thicknesses of 1st underframe, 2nd underframe, solebar and roof frame were selected by design variables in order to conduct size optimization. The results of the size optimization analysis showed that the weight of the aluminum extrusion could be reduced by 0.61 tons (5.60%) compared to the weight of the original carbody structure.

Keywords: double deck high-speed train, size optimization, weigh-reduction, aluminum extrusion

Procedia PDF Downloads 272

Authors: Tu-Chieh Hung, Wei-Mon Yan, Xiao-Dong Wang, Yu-Xian Huang

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This work employs a combined optimization procedure including a simplified conjugate-gradient method and a three-dimensional fluid flow and heat transfer model to study the optimal geometric parameter design of double-layered microchannel heat sinks. The overall thermal resistance RT is the objective function to be minimized with number of channels, N, the channel width ratio, β, the bottom channel aspect ratio, αb, and upper channel aspect ratio, αu, as the search variables. It is shown that, for the given bottom area (10 mm×10 mm) and heat flux (100 W cm-2), the optimal (minimum) thermal resistance of double-layered microchannel heat sinks is about RT=0.12 ℃/m2W with the corresponding optimal geometric parameters N=73, β=0.50, αb=3.52, and, αu= 7.21 under a constant pumping power of 0.05 W. The optimization process produces a maximum reduction by 52.8% in the overall thermal resistance compared with an initial guess (N=112, β=0.37, αb=10.32 and, αu=10.93). The results also show that the optimal thermal resistance decreases rapidly with the pumping power and tends to be a saturated value afterward. The corresponding optimal values of parameters N, αb, and αu increase while that of β decrease as the pumping power increases. However, further increasing pumping power is not always cost-effective for the application of heat sink designs.

Keywords: optimization, double-layered microchannel heat sink, simplified conjugate-gradient method, thermal resistance

Procedia PDF Downloads 467

Authors: P. Monginaud, J. C. Baudey

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The synchronous, low-voltage command for JFET Rectifiers has many applications: indeed, replacing the traditional diodes by these components allows enhanced performances in gain, linearity and phase shift. We introduce here a new bridge, including JFET associated with pull-down, bipolar command systems, and double-purpose logic gates.

Keywords: synchronous, rectifier, MOSFET, JFET, bipolar command system, push-pull circuits, double-purpose logic gates

Procedia PDF Downloads 340

Authors: Iwan Setiawan, Bobby Eka Gunara, Katshuhiro Nakamura

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The theory to accelerate system on quantum dynamics has been constructed to get the desired wave function on shorter time. This theory is developed on adiabatic quantum dynamics which any regulation is done on wave function that satisfies Schrödinger equation. We show accelerated manipulation of WFs with the use of a parameter-dependent in asymmetric double-well potential and also when it’s influenced by electromagnetic fields.

Keywords: driving potential, Adiabatic Quantum Dynamics, regulation, electromagnetic field

Procedia PDF Downloads 309

Authors: S. A. Anuar, N. H. Hamid, M. H. Hashim, S. M. D. Salleh

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This paper present the experimental work on the seismic performance of double unit tunnel form building (TFB) subjected to in-plane lateral cyclic loading. A one third scale of 3-storey double unit of TFB is tested at ±0.01%, ±0.1%, ±0.25%, ±0.5%, ±0.75% and ±1.0% drifts until the structure achieves its strength degradation. After that, the TFB is repaired and retrofitted using additional shear wall, steel angle and CFRP sheet. A similar testing approach is applied to the specimen after repair and retrofit. The crack patterns, lateral strength, stiffness, ductility and equivalent viscous damping (EVD) were analyzed and compared before and after repair and retrofit. The result indicates that the lateral strength increases by 22 in pushing direction and 27% in pulling direction. Moreover, the stiffness and ductility obtained before and after retrofit increase tremendously by 87.87% and 39.66%, respectively. Meanwhile, the energy absorption measured by equivalent viscous damping obtained after retrofit increase by 12.34% in pulling direction. It can be concluded that the proposed retrofit method is capable to increase the lateral strength capacity, stiffness and energy absorption of double unit TFB.

Keywords: tunnel form building, in-plane lateral cyclic loading, crack pattern, lateral strength, stiffness, ductility, equivalent viscous damping, repair and retrofit

Procedia PDF Downloads 325

Authors: Husham Bayazed, Fatimah Yousif

Abstract:

Purpose of Presentation: The infant immune system has a reputation for being weak and underdeveloped when compared to the adult immune system, but the comparison isn’t quite fair. At the start, as the COVID-19 pandemic drags on and evolves, many Pediatricians and kids' parents have been left with renewed questions about the consequences and sequel of infection on children and the steps to be taken if their child has the symptoms of COVID-19 or tests positive. Recent Findings Literature reviews and recent studies revealed that children are better than adults at controlling SARS-CoV-2. There was conflicting evidence on age-related differences in ACE2 expression in the nose and lungs. But scientists who measured the ‘viral load’ in children's upper airways have seen no clear difference between children and adults. Moreover, the hypothesis is that kids might be more exposed to other coronaviruses common cold, with a production of ready protective antibodies to lock on to the pandemic coronavirus. But the evidence suggests that adults also have this immunity too. Strikingly, these ‘cross-reactive’ antibodies don’t offer any special protection. Summary One of the few silver linings of the Covid-19 pandemic is that children are relatively spared. The kid's Innate Immunity is hardly the whole story, the innate immune response against SARS-CoV-2 infection is early initiative calm with low immunological tone to prevent an overactive immunity and with rapidly repair damage to the lungs in contrast to stormy waves in adults. Therefore, Kids are at much lower risk of Covid-19 infection, and they are still winning the battle against Covid-19 with their innate immunity.

Keywords: Covid-19, kids, ACE2 receptors, immunity

Procedia PDF Downloads 68

Authors: Liu Bijin

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Floating breakwaters have several advantages, including being environmentally friendly, easy to construct, and cost-effective regardless of water depth. They have a broad range of applications in coastal engineering. However, they face significant challenges due to the unstable effect of wave dissipation, structural vulnerability, and high mooring system requirements. This paper investigates the wave dissipation performance of a floating breakwater structure. The structure consists of double cylinders, double vertical plates, and horizontal connecting plates. The investigation is carried out using physical model tests and numerical simulation methods based on STAR-CCM+. This paper discusses the impact of wave elements, relative vertical plate heights, and relative horizontal connecting plate widths on the wave dissipation performance of the double-cylinder, double-plate floating breakwater (DCDPFB). The study also analyses the changes in local vorticity and velocity fields around the DCDPFB to determine the optimal structural dimensions. The study found that the relative width of the horizontal connecting plate, the relative height of the vertical plate, and the size of the semi-cylinder are the key factors affecting the wave dissipation performance of the DCDPFB. The transmittance coefficient is minimally affected by the wave height and the depth of water entry. The local vortex and velocity field formed around the DCDPFB are important factors for dissipating wave energy. The test section of the DCDPFB, constructed according to the relative optimal structural dimensions, showed good wave dissipation performance during offshore prototype tests. The test section of DCDPFB, constructed with optimal structural dimensions, exhibits excellent wave dissipation performance in offshore prototype tests.

Keywords: floating breakwater, wave dissipation performance, transmittance coefficient, model test

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Authors: Mudassar Iqbal, Riaz Hussain, Khalid Mehmood, Farah Ali, Fazal Mahmood, Abdul Ghaffar

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Corynebacterium pseudotuberculosis is an important cause of caseous lymphadenitis (CL), a complex, chronic devastating and destructive disease of small ruminants. In present study, postmortem examination of Chinkara deer (n=25) was conducted in year 2014. Pus samples suggestive of CL were collected from the superficial lymph nodes, liver, spleen and lungs during necropsy and subjected to standard microbiological procedures for isolation and molecular analysis of bacterial pathogens. Pus samples collected from carcasses (25) presenting clinical lesions of C. pseudotuberculosis infection was identified in 19 (76%) carcasses on the basis of culture characteristics. The frequency of C. pseudotuberculosis bacterium was higher in older animals as compared to young animals. Grossly, multiple tubercles of variable size having caseous material were observed in liver, lungs, spleen and lymph nodes. Histopathologically, tissue sections from all the visceral organs were extensively plugged with abscess. In present study specific prolineiminopeptidase (PIP) gene of the C. pseudotuberculosis was amplified by the Polymerase chain reaction technique (PCR) in 17(25) cases. The efficient and reliable molecular analysis along with necropsy findings in present study can be used as valuable approach for diagnosis of caseous lymphadenitis in small ruminants.

Keywords: Chinkara deer, Corynebacterium pseudotuberculosis, Caseous lymphadenitis, PCR

Procedia PDF Downloads 458

Authors: Yong Ren, Yaping Zhang

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A numerical model has been developed to investigate the thermally triggered release kinetics for drug delivery using phase change material as shell of microcapsules. Biocompatible material n-Eicosane is used as demonstration. PCM shell of microcapsule will remain in solid form after the drug is taken, so the drug will be encapsulated by the shell, and will not be released until the target body part of lesion is exposed to external heat source, which will thermally trigger the release kinetics, leading to solid-to-liquid phase change. The findings can lead to better understanding on the key effects influencing the phase change process for drug delivery applications. The facile approach to release drug from core/shell structure of microcapsule can be well integrated with organic solvent free fabrication of microcapsules, using double emulsion as template in microfluidic aqueous two phase system.

Keywords: phase change material, drug release kinetics, double emulsion, microfluidics

Procedia PDF Downloads 332

Authors: Damian Janecki, Anna Jaskólska, Jarosław Marusiak, Artur Jaskólski

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The aim of this study was to assess double to single twitch ratio after two bouts of eccentric exercise of the elbow flexors. Maximal isometric torque, single and double twitch responses and low-frequency fatigue were assessed on the elbow flexors in 19 untrained male volunteers before, immediately after, 24 and 48 hours following two bouts of eccentric exercise consisted of 30 repetitions of lowering a dumbbell adjusted to ~75% of each individual's maximal isometric torque. Maximal isometric torque and electrically evoked responses decreased significantly in all measurements after the first bout of eccentric exercise (P<0.05). In measurements performed at 24 and 48 hours after the second bout both maximal voluntary isometric torque and electrically evoked contractions were significantly higher than in measurements performed after the fist bout (P<0.05). Although low-frequency fatigue significantly increased up to 48 hours after each bout of eccentric exercise, its values at 24 and 48 hours after the second bout were significantly lower than at respective time points after the first bout (P<0.05). Smaller changes in double to single twitch ratio at 24 and 48 hours after the second bout of eccentric exercise reflects repeated bout effect that confers protection against subsequent exercise-induced muscle damage.

Keywords: biceps brachii, electrical stimulation, lenghtening contractions, repeated bout effect

Procedia PDF Downloads 297

Authors: Kuen-Ming Shu, Jyun-Wei Chen

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Encapsulated O-rings are specifically designed to address the problem of sealing the most hostile chemicals and extreme temperature applications. Ultrasonic vibration hot embossing and ultrasonic welding techniques provide a fast and reliable method to fabricate encapsulated O-ring. This paper performs the design and analysis method of the acoustic horns with double extrusion to process tube double side flange simultaneously. The paper deals with study through Finite Element Method (FEM) of ultrasonic stepped horn used to process a capsulated O-ring, the theoretical dimensions of horns, and their natural frequencies and amplitudes are obtained through the simulations of COMOSOL software. Furthermore, real horns were fabricated, tested and verified to proof the practical utility of these horns.

Keywords: encapsulated O-rings, ultrasonic vibration hot embossing, flange making, acoustic horn, finite element analysis

Procedia PDF Downloads 298

Authors: Md. Danish Eqbal, Venkat Gundabala

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Microparticles and microcapsules are basically used as a carrier for cells, tissues, drugs, and chemicals. Due to its biocompatibility, non-toxicity and biodegradability, alginate based microparticles have numerous applications in drug delivery, tissue engineering, organ repair and transplantation, etc. The production of uniform monodispersed microparticles was a challenge for the past few decades. However, emergence of microfluidics has provided controlled methods for the generation of the uniform monodispersed microparticles. In this work, we present a successful method for the generation of both microparticles and microcapsules (single and double core) using merging approach of two droplets, completely inside the microfluidic device. We have fabricated hybrid glass- PDMS (polydimethylsiloxane) based microfluidic device which has coflow geometry as well as the T junction channel. Coflow is used to generate the single as well as double oil-alginate emulsion in oil and T junction helps to form the calcium chloride droplets in oil. The basic idea is to match the frequency of the alginate droplets and calcium chloride droplets perfectly for controlled generation. Using the merging of droplets technique, we have successfully generated the microparticles and the microcapsules having single core as well as double and multiple cores. The cores in the microcapsules are very stable, well separated from each other and very intact as seen through cross-sectional confocal images. The size and the number of the cores along with the thickness of the shell can be easily controlled by controlling the flowrate of the liquids.

Keywords: double-core, droplets, microcapsules, microparticles

Procedia PDF Downloads 228

Authors: David Ross Cameron

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In an attempt to alleviate the educational planning problem, double-shift schools have been created throughout various regions in Jordan, namely communities closer to the Syrian border, where a large portion of the refugee population settled, allowing Jordanians to attend the morning-shift and Syrians to attend the afternoon-shift. Subsequently, overcrowded classrooms have added a significant amount of stress on school facilities and teacher capacities. Established national policies and the implementation of inclusive educational practices have been jeopardized. In particular, teachers’ and student’s attitudes of the importance of inclusive education provisions in the classroom have deteriorated. To have a more comprehensive understanding of the current situation and possible plan for intervention, a focus study was carried out at a double-shift Jordanian/Syrian girls’ public school in Irbid, Jordan. Interviews and surveys of 29 students with physical, learning, emotional and behavioral disabilities, 33 students without any special needs and nine teachers were included with a mixed-method social research approach to highlight the current attitudes that students and teachers held and factors that contributed to shaping their inclinations and beliefs of inclusive education.

Keywords: capacity building, development, double-shift, Irbid, inclusive education, Jordan, pedagogy, planning, policy, refugee, special education, special needs, vulnerable population

Procedia PDF Downloads 234

Authors: Nataša Todorović, Jovana Nikolov

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Despite the great interest in β⁻β⁻ decay, β⁺β⁺ decays are rarely investigated due to the low probability of detecting these processes with available low-level equipment. If β⁺β⁺, β⁺EC, or ECEC decay occurs in a thin sample of a material, the positrons will be stopped and annihilated inside the material, leading to the emission of two or four coincidence gamma photons energy of 511 keV. The paper presents the results of measurements of double beta decay of ⁶⁴Zn, ⁵⁰Cr, and ⁵⁴Fe isotopes. In the first experiment, 511-keV gamma rays originating from the annihilation of positrons in natural zinc were measured by a coincidence technique to obtain a non-zero value for the (0ν+2ν) half-life. In the second experiment, the result of measuring double beta decay of ⁵⁰Cr is presented, which suggests a result other than zero at 95% CL and gives the lowest limit for the half-life of this process. In the third experiment, neutrino-less ECEC decay of ⁵⁴Fe was examined. Under the decay theory, gamma rays are emitted whose energy does not coincide with the energies of gamma rays emitted by nuclei from known discrete excited states. Iron shield of an internal volume of 1 m³ and thickness of 25 cm served as a source for measuring the (0ν+2ν) process in ⁵⁴Fe, whose yield in natural iron is 5.4%. We obtain the lower limit for the half-life for ⁵⁴Fe: T(0ν, K, K)>4.4x10²⁰ yr, T(0ν, K, L)>4.1x10²⁰ yr, and T(0ν, L, L)>5.0x10²⁰ yr. For ⁵⁰Cr limit for the half-life is T(0ν+2ν)>1.3(6)x10¹⁸ yr, and for ⁶⁴Zn T(0ν+2ν, ECβ+)=1.1(0.9)x10⁹ years.

Keywords: neutrinoless double beta decay, half-life, ⁶⁴Zn, ⁵⁰Cr, and, ⁵⁴Fe

Procedia PDF Downloads 86

Authors: Komal Khan, Hafsa Zaneb, Saima Masood, Muhammad Younus, Sanan Raza

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Cigarette smoke induces many physiological and pathological changes in respiratory tract like goblet cell hyperplasia and regional distention of airspaces. It is also associated with elevation of inflammatory profiles in different airway compartments. As probiotics are generally known to promote mucosal tolerance, it was postulated that prophylactic use of probiotics can be helpful in reduction of respiratory damage induced by cigarette smoke exposure. Twenty-four adult mice were randomly divided into three groups (cigarette-smoke (CS) group, cigarette-smoke+ Lactobacillus (CS+ P) group, control (Cn) group), each having 8 mice. They were exposed to cigarette smoke for 28 days (6 cigarettes/ day for 6 days/week). Wright-Giemsa staining of bronchoalveolar lavage fluid (BALF) was performed in three mice per group. Tissue samples of trachea and lungs of 7 mice from each group were processed by paraffin embedding technique for haematoxylin & eosin (H & E) and alcian blue- periodic acid-Schiff (AB-PAS) staining. Then trachea (goblet cell number, ratio and loss of cilia) and lungs (airspace distention) were studied. The results showed that the number of goblet cells was increased in CS group as a result of defensive mechanism of the respiratory system against irritating substances. This study also revealed that the cells of CS group having acidic glycoprotein were found to be higher in quantity as compared to those containing neutral glycoprotein. However, CS + P group showed a decrease in goblet cell index due to enhanced immunity by prophylactically used probiotics. Moreover, H & E stained tracheas showed significant loss of cilia in CS group due to propelling of mucous but little loss in CS + P group because of having good protective tracheal epithelium. In lungs, protection of airspaces was also much more evident in CS+ P group as compared to CS group having distended airspaces, especially at 150um distance from terminal bronchiole. In addition, a comprehensive analysis of inflammatory cells population of BALF showed neutrophilia and eosinophilia was significantly reduced in CS+ P group. This study proved that probiotics are found to be useful for reduction of changes in micro-architecture of the respiratory system. Thus, dietary supplementation of probiotic as prophylactic measure can be useful in achieving immunomodulatory effects.

Keywords: cigarette smoke, probiotics, goblet cells, airspace enlargement, BALF

Procedia PDF Downloads 335

Authors: Norazam Arbin, Habibis Saleh, Ammar Alsabery, Ishak Hashim

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Double-diffusive natural convection in an open top cavity with partial vertical heating and salting sources is investigated numerically. Different temperatures and concentrations are applied at the source location on the right and left walls while the other remains adiabatic except at the open top surface. Various combinations of sources arrangements are imposed at the vertical walls in order to observe the significant impact to the convection. An iterative finite different method is used to solve the dimensionless governing equations. The effects of Marangoni number and sources arrangements on the contours of streamlines, isotherms, and concentrations are visualized as the outcome of the numerical solutions. The average Nusselt and Sherwood number are presented for various sources arrangements. It is clearly observed that the sources arrangements gave major impact on the heat and mass transfer rates. A horizontal-like pattern is found for sources arrangements that near the top-free surface.

Keywords: double-diffusive, Marangoni effect, partial heating, salting

Procedia PDF Downloads 382

Authors: Ahmed H. Amer, A. Amar, Sh. Hamada, I. I. Bondouk, F. A. El-Hussiny

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Elastic scattering of α-particles from 9Be and 11B nuclei at different alpha energies have been analyzed. Optical model parameters (OMPs) of α-particles elastic scattering by these nuclei at different energies have been obtained. In the present calculations, the real part of the optical potential are derived by folding of nucleon-nucleon (NN) interaction into nuclear matter density distribution of the projectile and target nuclei using computer code FRESCO. A density-dependent version of the M3Y interaction (CDM3Y6), which is based on the G-matrix elements of the Paris NN potential, has been used. Volumetric integrals of the real and imaginary potential depth (JR, JW) have been calculated and found to be energy dependent. Good agreement between the experimental data and the theoretical predictions in the whole angular range. In double folding (DF) calculations, the obtained normalization coefficient Nr is in the range 0.70–1.32.

Keywords: elastic scattering, optical model, double folding model, density distribution

Procedia PDF Downloads 276

Authors: Sheam-Chyun Lin, Wei-Kai Chen, Hung-Cheng Yen, Yung-Jen Cheng, Yu-Cheng Chen

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Result from the constant dwindle in natural resources, the alternative way to reduce the costs in our daily life would be urgent to be found in the near future. As the ancient technique based on the theory of solar chimney since roman times, the double-skin façade are simply composed of two large glass panels in purpose of daylighting and also natural ventilation in the daytime. Double-skin façade is generally installed on the exterior side of buildings as function as the window, so there’s always a huge amount of passive solar energy the façade would receive to induce the airflow every sunny day. Therefore this article imposes a domestic double-skin window for residential usage and attempts to improve the volume flow rate inside the cavity between the panels by the frame geometry design, the installation of outlet guide plate and the solar energy collection system. Note that the numerical analyses are applied to investigate the characteristics of flow field, and the boundary conditions in the simulation are totally based on the practical experiment of the original prototype. Then we redesign the prototype from the knowledge of the numerical results and fluid dynamic theory, and later the experiments of modified prototype will be conducted to verify the simulation results. The velocities at the inlet of each case are increase by 5%, 45% and 15% from the experimental data, and also the numerical simulation results reported 20% improvement in volume flow rate both for the frame geometry design and installation of outlet guide plate.

Keywords: solar energy, double-skin façades, thermal buoyancy, fluid machinery

Procedia PDF Downloads 467

Authors: Bo-Bin Xiaoa, Chia-Yi Liua

Abstract:

In the task of searching for anomalous radiation sources, personnel holding radiation detectors to search for radiation sources may be exposed to unnecessary radiation risk, and automated search using machines becomes a required project. The research uses various sophisticated algorithms, which are double Q learning, dueling network, and NoisyNet, of deep reinforcement learning to search for radiation sources. The simulation environment, which is a 10*10 grid and one shielding wall setting in it, improves the development of the AI model by training 1 million episodes. In each episode of training, the radiation source position, the radiation source intensity, agent position, shielding wall position, and shielding wall length are all set randomly. The three algorithms are applied to run AI model training in four environments where the training shielding wall is a full-shielding wall, a lead wall, a concrete wall, and a lead wall or a concrete wall appearing randomly. The 12 best performance AI models are selected by observing the reward value during the training period and are evaluated by comparing these AI models with the gradient search algorithm. The results show that the performance of the AI model, no matter which one algorithm, is far better than the gradient search algorithm. In addition, the simulation environment becomes more complex, the AI model which applied Double DQN combined Dueling and NosiyNet algorithm performs better.

Keywords: double Q learning, dueling network, NoisyNet, source searching

Procedia PDF Downloads 84

Authors: Quan Li, Dongcai Shen, Zhengting Xiao, Xin Liu Mingrui Wu, Licheng Liu, Qin Li, Xianguo Li, Wentai Wang

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Direct electrocatalytic nitrogen oxidation (NOR) provides a promising alternative strategy for synthesizing high-value-added nitric acid from widespread N₂, which overcomes the disadvantages of the Haber-Bosch-Ostwald process. However, the NOR process suffers from the limitation of high N≡N bonding energy (941 kJ mol− ¹), sluggish kinetics, low efficiency and yield. It is a prerequisite to develop more efficient electrocatalysts for NOR. Herein, we synthesized double-shelled CeO₂ hollow spheres (D-CeO₂) and further modified with Ti₃C₂ MXene quantum dots (MQDs) for electrocatalytic N₂ oxidation, which exhibited a NO₃− yield of 71.25 μg h− ¹ mgcat− ¹ and FE of 31.80% at 1.7 V. The unique quantum size effect and abundant edge active sites lead to a more effective capture of nitrogen. Moreover, the double-shelled hollow structure is favorable for N₂ fixation and gathers intermediate products in the interlayer of the core-shell. The in-situ infrared Fourier transform spectroscopy confirmed the formation of *NO and NO₃− species during the NOR reaction, and the kinetics and possible pathways of NOR were calculated by density functional theory (DFT). In addition, a Zn-N₂ reaction device was assembled with D-CeO₂/MQDs as anode and Zn plate as cathode, obtaining an extremely high NO₃− yield of 104.57 μg h− ¹ mgcat− ¹ at 1 mA cm− ².

Keywords: electrocatalytic N₂ oxidation, nitrate production, CeO₂, MXene quantum dots, double-shelled hollow spheres

Procedia PDF Downloads 28

Authors: Mohamed Habila, Ahmed Mohamed El-Toni, Mohamed Sheikh Moshab, Abdulrhman Al-Awadi, Zeid AL Othman

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Water pollution with dyes is a critical environmental issue because off the huge amount of dyes disbarred annually, which cause severe damage for the ecosystem and human life. The main raison for this severs pollution is the rapid industrial development which led to more production of harmful pollutants. on the other hand, the core shell based magnetic materials have showed amazing character for controlling the material synthesis with the targeted structure to enhance the adsorptive removal of pollutants. Herein, the Fe3O4core-meso SiO2/TiO2 double shell have been prepared for methylene blue dye adsorption. the preparation procedure is controlled to prepare the magnetic core with further coating layers from silica and titania. The prepared Fe3O4core-meso SiO2/TiO2 double shell showed adsorption capacity for methylene blue removal about 50 mg/g at pH 6 after 80 min contact time form 50 ppm methylene blue solution. The adsorption process of methylene blue onto Fe3O4core-meso SiO2/TiO2 double shell was well fitted with the pseudo-second-order kinetic model and freundlish isotherm, indicating a quick and multilayer adsorption mechanism.

Keywords: magnetic core, silica shell, titania shell, water treatment, methylene blue, solvo-thermal process, adsorption

Procedia PDF Downloads 99

Authors: C. H. Chang, R. Z. Qiu, C. W. Tsao, Y. H. Cheng, C. H. Chen, W. J. Hsueh

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Characteristics of photoluminescence (PL) in a resonant quasi-periodic double-period quantum wells (DPQW) are demonstrated. The maximum PL intensity in the DPQW is remarkably greater than that in a traditional periodic QW (PQW) under the Bragg or anti-Bragg conditions. The optimal PL spectrum in the DPQW has an asymmetrical form instead of the symmetrical form in the PQW. Moreover, there are two large values of PL intensity in the DPQW, which also differs from the PQW.

Keywords: Photoluminescence, quantum wells, quasiperiodic structure

Procedia PDF Downloads 693

Authors: Minh Tu Le, Quang Huy Nguyen, Mai Lan Nguyen

Abstract:

Bonding characteristics between pavement layers have an important influence on responses of pavement structures. This paper deals with analytical solution for the stresses, strains, and deflections of double-layered asphalt pavement structure. This solution is based on the homogeneous half-space of layered theory developed by Burmister (1943). The partial interaction between the layers is taken into account by considering an interface bonding behavior which is obtained by push-out shear test. Numerical applications considering three cases of bonding (unbonded, partially bonded, and fully bonded overlays) are carried out to the influence of the interface bonding on the structural behavior of asphalt pavement under static loading. Further, it was observed that numerical results indicate that the horizontal shear reaction modulus at the interface (Ks) will significantly affect pavement structure behavior.

Keywords: analytical solution, interface bonding, shear test keyword, double-layered asphalt, shear reaction modulus

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Authors: Ieva Bruzauskaite, Jovile Raudoniute, Karina Poliakovaite, Danguole Zabulyte, Daiva Bironaite, Ruta Aldonyte

Abstract:

Introduction: Air pollution is a growing global problem which has been shown to be responsible for various adverse health outcomes. Immunotoxicity, such as dysregulated inflammation, has been proposed as one of the main mechanisms in air pollution-associated diseases. Chronic obstructive pulmonary disease (COPD) is among major morbidity and mortality causes worldwide and is characterized by persistent airflow limitation caused by the small airways disease (obstructive bronchiolitis) and irreversible parenchymal destruction (emphysema). Exact pathways explaining the air pollution induced and mediated disease states are still not clear. However, modern societies understand dangers of polluted air, seek to mitigate such effects and are in need for reliable biomarkers of air pollution. We hypothesise that post-translational modifications of structural proteins, e.g. citrullination, might be a good candidate biomarker. Thus, we have designed this study, where mice were exposed to diesel exhaust and the ongoing protein modifications and inflammation in lungs and other tissues were assessed. Materials And Methods: To assess the effects of diesel exhaust a in vivo study was designed. Mice (n=10) were subjected to everyday 2-hour exposure to diesel exhaust for 14 days. Control mice were treated the same way without diesel exhaust. The effects within lung and other tissues were assessed by immunohistochemistry of formalin-fixed and paraffin-embedded tissues. Levels of inflammation and citrullination related markers were investigated. Levels of parenchymal damage were also measured. Results: In vivo study corroborates our own data from in vitro and reveals diesel exhaust initiated inflammatory shift and modulation of lung peptidyl arginine deiminase 4 (PAD4), citrullination associated enzyme, levels. In addition, high levels of citrulline were observed in exposed lung tissue sections co-localising with increased parenchymal destruction. Conclusions: Subacute exposure to diesel exhaust renders mice lungs inflammatory and modifies certain structural proteins. Such structural changes of proteins may pave a pathways to lost/gain function of affected molecules and also propagate autoimmune processes within the lung and systemically.

Keywords: air pollution, citrullination, in vivo, lungs

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Authors: Jiajia Yao, Guanlin Wu, Fang Liu, Junshuai Xue, Yue Hao

Abstract:

This study reports on the epitaxial growth of a GaN-based resonant tunneling diode (RTD) structure with stable and repeatable double negative differential resistance (NDR) characteristics at room temperature on a c-plane GaN-on-sapphire template using plasma-assisted molecular beam epitaxy (PA-MBE) technology. In this structure, two independent AlN/GaN RTDs are epitaxially connected in series in the vertical growth direction through a silicon-doped GaN layer. As the collector electrode bias voltage increases, the two RTDs respectively align the ground state energy level in the quantum well with the 2DEG energy level in the emitter accumulation well to achieve quantum resonant tunneling and then reach the negative differential resistance (NDR) region. The two NDR regions exhibit similar peak current densities and peak-to-valley current ratios, which are 230 kA/cm² and 249 kA/cm², 1.33 and 1.38, respectively, for a device with a collector electrode mesa diameter of 1 µm. The consistency of the NDR is much higher than the results of on-chip discrete RTD device interconnection, resulting from the smaller chip area, fewer interconnect parasitic parameters, and less process complexity. The methods and results presented in this paper show the brilliant prospects of GaN RTDs in the development of multi-value logic digital circuits.

Keywords: MBE, AlN/GaN, RTDs, double NDR

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Authors: Gabriela C. Caldas, Fernanda C. Jacome, Arthur da C. Rasinhas, Ortrud M. Barth, Flavia B. dos Santos, Priscila C. G. Nunes, Yuli R. M. de Souza, Pedro Paulo de A. Manso, Marcelo P. Machado, Debora F. Barreto-Vieira

Abstract:

The establishment of animal models for studies of DENV infections has been challenging, since circulating epidemic viruses do not naturally infect nonhuman species. Such studies are of great relevance to the various areas of dengue research, including immunopathogenesis, drug development and vaccines. In this scenario, the main objective of this study is to verify possible morphological changes, as well as the presence of antigens and viral RNA in lung samples from BALB/c mice experimentally infected with an epidemic and non-neuroadapted DENV-3 strain. Male BALB/c mice, 2 months old, were inoculated with DENV-3 by intravenous route. After 72 hours of infection, the animals were euthanized and the lungs were collected. Part of the samples was processed by standard technique for analysis by light and transmission electronic microscopies and another part was processed for real-time PCR analysis. Morphological analyzes of lungs from uninfected mice showed preserved tissue areas. In mice infected with DENV-3, the analyzes revealed interalveolar septum thickening with presence of inflammatory infiltrate, foci of alveolar atelectasis and hyperventilation, bleeding foci in the interalveolar septum and bronchioles, peripheral capillary congestion, accumulation of fluid in the blood capillary, signs of interstitial cell necrosis presence of platelets and mononuclear inflammatory cells circulating in the capillaries and/or adhered to the endothelium. In addition, activation of endothelial cells, platelets, mononuclear inflammatory cell and neutrophil-type polymorphonuclear inflammatory cell evidenced by the emission of cytoplasmic membrane prolongation was observed. DEN-like particles were seen in the cytoplasm of endothelial cells. The viral genome was recovered from 3 in 12 lung samples. These results demonstrate that the BALB / c mouse represents a suitable model for the study of the histopathological changes induced by DENV infection in the lung, with tissue alterations similar to those observed in human cases of DEN.

Keywords: BALB/c mice, dengue, histopathology, lung, ultrastructure

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