Search results for: surface treatment

Authors: Sheila Shahidi

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UV protection by fabrics has recently become a focus of great interest, particularly in connection with environmental degradation or ozone layer depletion. Fabrics provide simple and convenient protection against UV radiation (UVR), but not all fabrics offer sufficient UV protection. To describe the degree of UVR protection offered by clothing materials, the ultraviolet protection factor (UPF) is commonly used. UV-protective fabric can be generated by application of a chemical finish using normal wet-processing methodologies. However, traditional wet-processing techniques are known to consume large quantities of water and energy and may lead to adverse alterations of the bulk properties of the substrate. Recently, usage of plasmas to generate physicochemical surface modifications of textile substrates has become an intriguing approach to replace or enhance conventional wet-processing techniques. In this research work the effect of plasma treatment on UV protection properties of fabrics was investigated. DC magnetron sputtering was used and the parameters of plasma such as gas type, electrodes, time of exposure, power and, etc. were studied. The morphological and chemical properties of samples were analyzed using Scanning Electron Microscope (SEM) and Furrier Transform Infrared Spectroscopy (FTIR), respectively. The transmittance and UPF values of the original and plasma-treated samples were measured using a Shimadzu UV3101 PC (UV–Vis–NIR scanning spectrophotometer, 190–2, 100 nm range). It was concluded that, plasma which is an echo-friendly, cost effective and dry technique is being used in different branches of the industries, and will conquer textile industry in the near future. Also it is promising method for preparation of UV protection textile.

Keywords: fabric, plasma, textile, UV protection

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Authors: Daniele Zullino, Gabriel Thorens, Léonice Furtado, Federico Seragnoli, Radu Iuga, Louise Penzenstadler

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Context: Since the start of the 21st century, there has been a resurgence of interest in psychedelics, marked by a renewed focus on scientific investigations into their therapeutic potential. While psychedelic therapy has gained recognition for effectively treating depression and anxiety disorders, notable progress has been made in the clinical development of substances like psilocybin. Moreover, mounting evidence suggests promising applications of Lysergic acid diethylamide (LSD) and psilocybin in the field of addiction medicine. In Switzerland, compassionate treatment with LSD and psilocybin has been permitted since 2014 through exceptional licenses granted by the Federal Office of Public Health. This treatment approach is also available within the Geneva treatment program, extending its accessibility to patients undergoing opioid-assisted treatment involving substances like morphine and diacetylmorphine. The aim of this study is to assess the feasibility of psychedelic-assisted therapy in patients with opioid use disorder who are undergoing opioid-assisted treatment. This study addresses the question of whether psychedelic-assisted therapy can be successfully implemented in patients with opioid use disorder. It also explores the effects of psychedelic therapy on the patient's experiences and outcomes. Methodology: This is an open case series on six patients who have undergone at least one session with either LSD (100-200 micrograms) or psilocybin (20-40 mg). The patients were assessed using the Five Dimensional Altered States of Consciousness (5D-ASC)-Scale. The data were analyzed descriptively to identify patterns and trends in the patients' experiences. Results: The patients experienced substantial positive psychedelic effects during the psychedelic sessions without significant adverse effects. The patients reported positive experiences and improvements in their condition. Conclusion: The findings of this study support the feasibility and potential efficacy of psychedelic-assisted therapy in patients undergoing opioid-assisted treatment.

Keywords: psychedelics, psychedelic-assisted treatment, opioid use disorder, addiction, LSD, psilocybin

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Authors: Amin Abbasi, Fariborz Shekari, Seyed Bahman Mousavi

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Seed aging during storage is a complex biochemical and physiological processes that can lead to reduce seed germination. This phenomenon associated with increasing of total antioxidant activity during aging. To study the effects of hormones on seed aging, aged wheat seeds (control, 90 and 80% viabilities) were treated with GA3, Salicylic Acid, and paclobutrazol and antioxidant system were investigated as molecular biomarkers for seed vigor. The results showed that, seed priming treatment significantly affected germination percentage, normality seedling percentage, H2O2, MDA, CAT, APX, and GPX activates. Maximum germination percentage achieve in GA3 priming in control treatment. Germination percentage and normal seedling percentage increased in other GA3 priming treatment compared with other hormones. Also aging increased MDA, H2O2 content. MDA is considered sensitive marker commonly used for assessing membrane lipid peroxidation and H2O2result in toxicity to cellular membrane system and damages to plant cells. Amount of H2O2 and MDA declined in GA3 treatment. CAT, GPX and APX activities were reduced by increasing the aging time and at different levels of priming. The highest APX activity was observed in Salicylic Acid control treatment and the highest GPX and CAT activity was obtained in GA3 control treatment. The lowest MDA and H2O2 showed in GA3 control treatment, too. Hormone priming increased Antioxidant enzyme activity and decreased amount of reactive oxygen space and malondialdehyde (MDA) under aging treatment. Also, GA3 priming treatments have a significant effect on germination percentage and number of normal seedling. Generally aging seed, increase ROS and lipid peroxidation. Antioxidant enzymes activity of aged seeds increased after hormone priming.

Keywords: hormones priming, wheat, aging seed, antioxidant, lipid peroxidation

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Authors: Rian Diana, Naufal Muharam Nurdin, Faisal Anwar, Hadi Riyadi, Ali Khomsan

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The use of traditional medicine (herbs and medicinal plants) are common among Indonesian people especially the elderly. Few study explore the use of medicinal plants in middle aged people. This study aims to collect information on the use of medicinal plants in middle aged people in rural areas. This cross sectional study included 224 subjects aged 45-59 years old and conducted in Cianjur District, West Java in 2014. Semi-structured questionnaires were used to collect information about preference in treatment of illness, the use of medicinal plants, and their purposes. Information also recorded plant names, parts used, mode of preparation, and dosage. Buying drugs in stall (83.9%) is the first preference in treatment of illness, followed by modern treatment 19.2% (doctors) and traditional treatment 17.0% (herbs/medicinal plants). 87 subjects (38.8%) were using herbs and medicinal plants for curative (66.7%), preventive (31.2%), and rehabilitative (2.1%) purposes. In this study, 48 species are used by the subjects. Physalis minima L. 'cecenet', Orthosiphon aristatus Mic. 'kumis kucing', and Annona muricata 'sirsak' are commonly used for the treatment of hypertension and stiffness. Leaves (64.6%) are the most common part used. Medicinal plants were washed and boiled in a hot water. Subject drinks the herbs with a different dosage. One in three middle aged people used herbal and medicinal plants for curative and preventive treatment particularly hypertension and stiffness. Increasing knowledge about herbal or medicinal plants dosage and their interaction with medical drugs are important to do.Doses vary between 1-3 glasses/day for treatment and 1-2 glasses/months for prevention of diseases.

Keywords: herbs, hypertension, medicinal plants, middle age, rural

Procedia PDF Downloads 239

Authors: Sandrine Delpeux-Ouldriane, Min Cai, Laurent Duclaux, Laurence Reinert, Fabrice Muller

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A novel hybrid adsorbent, based on chitosan biopolymer, clays and activated carbon was prepared. Hybrid chitosan beads containing dispersed clays and activated carbons were prepared by precipitation in basic medium. Such a composite material is still very porous and presents a wide adsorption spectrum. The obtained composite adsorbent is able to handle all the pollution types including heavy metals, polar and hydrophobic organic molecules and nitrates. It could find a place of choice in tertiary water treatment processes or for an ‘at source’ treatment concerning chemical or pharmaceutical industries.

Keywords: adsorption, chitosan, clay mineral, activated carbon

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Authors: Jianhua Zhou, Yuwen Zhang

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A two-step multigrid approach is proposed to solve the inverse heat conduction problem in a 3-D object under laser irradiation. In the first step, the location of the laser center is estimated using a coarse and uniform grid system. In the second step, the front-surface temperature is recovered in good accuracy using a multiple grid system in which fine mesh is used at laser spot center to capture the drastic temperature rise in this region but coarse mesh is employed in the peripheral region to reduce the total number of sensors required. The effectiveness of the two-step approach and the multiple grid system are demonstrated by the illustrative inverse solutions. If the measurement data for the temperature and heat flux on the back surface do not contain random error, the proposed multigrid approach can yield more accurate inverse solutions. When the back-surface measurement data contain random noise, accurate inverse solutions cannot be obtained if both temperature and heat flux are measured on the back surface.

Keywords: conduction, inverse problems, conjugated gradient method, laser

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Authors: Vasu Velagapudi, G. Suresh

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PTFE/HNTs nanocomposites are fabricated with 4%, 6%, and 8% by weight fraction, and the optimization study of wear parameters are performed using response surface methodology (RSM). The experiments are carried out on a pin on disc (POD) wear tester under different operating parameters planned according to Taguchi L27 orthogonal array. The input factors considered are wt% HNTs addition, sliding velocity, load, and distance with three levels for each factor. From ANOVA: The factors load, speed and distance and their interactions have a significant effect on COF. Also for SWR, composition factor and interaction of load and speed are observed to be significant ( < 0.05) Optimum input parameters corresponding to desirability 1 are found to be: COF (0.11) and SWR (17.5)×10⁻⁶ (mm3/N-m) at 6.34 wt% of composition, 5N of load, 2 km of distance and 1 m/sec of velocity.

Keywords: PTFE/HNT, nanocomposites, response surface methodology (RSM), specific wear rate

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Authors: Komal Vig

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Cardiovascular disease (CVD)-related deaths occur in 17.3 million people globally each year, accounting for 30% of all deaths worldwide, with a predicted annual incidence of deaths to reach 23.3 million globally by 2030. Autologous bypass grafts remain an important therapeutic option for the treatment of CVD, but the poor quality of the donor patient’s blood vessels, the invasiveness of the resection surgery, and postoperative movement restrictions create issues. The present study is aimed to improve the endothelialization of intimal surface of graft by using low temperature plasma (LTP) to increase the cell attachment and proliferation. Polytetrafluoroethylene (PTFE) was treated with LTP. Air was used as the feed-gas, and the pressure in the plasma chamber was kept at 800 mTorr. Scaffolds were also modified with gelatin and collagen by dipping method. Human umbilical vein endothelial cells (HUVEC) were plated on the developed scaffolds, and cell proliferation was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and by microscopy. mRNA expressions levels of different cell markers were investigated using quantitative real-time PCR (qPCR). XPS confirmed the introduction of oxygenated functionalities from LTP. HUVEC cells showed 80% seeding efficiency on the scaffold. Microscopic and MTT assays indicated increase in cell viability in LTP treated scaffolds, especially when treated with gelatin or collagen, compared to untreated scaffolds. Gene expression studies shows enhanced expression of cell adhesion marker Integrin- α 5 gene after LTP treatment. LTP treated scaffolds exhibited better cell proliferation and viability compared to untreated scaffolds. Protein treatment of scaffold increased cell proliferation. Based on our initial results, more scaffolds alternatives will be developed and investigated for cell growth and vascularization studies. Acknowledgments: This work is supported by the NSF EPSCoR RII-Track-1 Cooperative Agreement OIA-2148653.

Keywords: LTP, HUVEC cells, vascular graft, endothelialization

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Authors: Serges Mendomo Meye, Li Guowei, Shen Zhenzhong

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Earthquake is one of the main loads threatening dam safety. Once the dam is damaged, it will bring huge losses of life and property to the country and people. Therefore, it is very important to research the seismic safety of the dam. Due to the complex foundation conditions, high fortification intensity, and high scientific and technological content, it is necessary to adopt reasonable methods to evaluate the seismic safety performance of concrete arch dams built and under construction in strong earthquake areas. Structural seismic vulnerability analysis can predict the probability of structural failure at all levels under different intensity earthquakes, which can provide a scientific basis for reasonable seismic safety evaluation and decision-making. In this paper, the response surface method (RSM) is applied to the seismic vulnerability analysis of arch dams, which improves the efficiency of vulnerability analysis. Based on the central composite test design method, the material-seismic intensity samples are established. The response surface model (RSM) with arch crown displacement as performance index is obtained by finite element (FE) calculation of the samples, and then the accuracy of the response surface model (RSM) is verified. To obtain the seismic vulnerability curves, the seismic intensity measure ??(?1) is chosen to be 0.1~1.2g, with an interval of 0.1g and a total of 12 intensity levels. For each seismic intensity level, the arch crown displacement corresponding to 100 sets of different material samples can be calculated by algebraic operation of the response surface model (RSM), which avoids 1200 times of nonlinear dynamic calculation of arch dam; thus, the efficiency of vulnerability analysis is improved greatly.

Keywords: high concrete arch dam, performance index, response surface method, seismic vulnerability analysis, vector-valued intensity measure

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Authors: N. A. Ahmad Zubairi, H. Takaijudin, K. W. Yusof

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Pesticides have been used widely over the world in agriculture to protect from pests and reduce crop losses. However, it affects the environment with toxic chemicals. Exceed of toxic constituents in the ecosystem will result in bad side effects. The hydrological cycle is related to the existence of pesticides and heavy metal which it can penetrate through varieties of sources into the soil or water bodies, especially runoff. Therefore, proper mechanisms of pesticide and heavy metal removal should be studied to improve the quality of ecosystem free or reduce from unwanted substances. This paper reviews the use of treatment train and its mechanisms to minimize pesticides and heavy metal from agricultural runoff. Organochlorine (OCL) is a common pesticide that was found in the agricultural runoff. OCL is one of the toxic chemicals that can disturb the ecosystem such as inhibiting plants' growth and harm human health by having symptoms as asthma, active cancer cell, vomit, diarrhea, etc. Thus, this unwanted contaminant gives disadvantages to the environment and needs treatment system. Hence, treatment train by bioretention system is suitable because removal efficiency achieves until 90% of pesticide removal with selected vegetated plant and additive.

Keywords: pesticides, heavy metal, agricultural runoff, bioretention, mechanism removal, treatment train

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Authors: Isobel Hambleton, Mark Carrington

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Trypanosoma brucei, the causal agent of a range of diseases in humans and livestock, evades the mammalian immune system through a population survival strategy based on the expression of a series of antigenically distinct variant surface glycoproteins (VSGs). RNAi mediated knockdown of the active VSG gene triggers a precytokinesis cell cycle arrest. To determine whether this phenotype is the result of reduced VSG transcript or depleted VSG protein, we used morpholino antisense oligonucleotides to block translation of VSG mRNA. The same precytokinesis cell cycle arrest was observed, suggesting that VSG protein abundance is monitored closely throughout the cell cycle. An inducible expression system has been developed to test various GPI-anchored proteins for their ability to rescue this cell cycle arrest. This system has been used to demonstrate that wild-type VSG expressed from a T7 promoter rescues this phenotype. This indicates that VSG expression from one of the specialised bloodstream expression sites (BES) is not essential for cell division. The same approach has been used to define the minimum essential features of a VSG necessary for function.

Keywords: bloodstream expression site, morpholino, precytokinesis cell cycle arrest, variant surface glycoprotein

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Authors: Shang-Hsin Ou, Yang-Chun Lin, Ke-Hao Cheng

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The year 2021 marked a historic drought in Taiwan, posing unprecedented challenges due to record-low rainfall and inadequate reservoir storage. The central region experienced water scarcity, leading to the implementation of "Groundwater Utilization at Construction Sites" for drought-resilient livelihood water supply. This study focuses on the establishment process of temporary groundwater treatment plants at construction sites in Taichung City, serving as a reference for future emergency response and the utilization of construction site groundwater. To identify suitable sites for groundwater reuse projects, site selection operations were carried out based on relevant water quality regulations and assessment principles. Subsequently, the planning and design of temporary water treatment plants were conducted, considering the water quality, quantity, and on-site conditions of groundwater wells associated with construction projects. The study consolidates the major water treatment facilities at each site and addresses encountered challenges during the establishment process. Practical insights gained from operating temporary groundwater treatment plants are presented, including improvements related to stable water quality, water quantity, equipment operation, and hydraulic control. In light of possible future droughts, this study provides an outlook and recommendations to expedite and improve the setup of groundwater treatment plants at construction sites. This includes considering on-site water abstraction, treatment, and distribution conditions. The study's results aim to offer practical guidelines for effectively establishing and managing such treatment plants, while offering experiences and recommendations for other regions facing similar emergencies, water shortages, and drought situations. These endeavors contribute to ensuring sustainable water supply for drought-resilient livelihoods and maintaining societal stability.

Keywords: drought resilience, groundwater treatment, construction site, water supply

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Authors: Tsu-Hsu Yen

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The interfacial gas adsorption presents a frequent challenge and opportunity for micro-/nano-fluidic operation. In this study, we investigate the wettability, gas accumulation, and nanobubble formation on various homogeneous surface conditions by using MD simulation, including a series of 3D and quasi-2D argon-water-solid systems simulation. To precisely determine the wettability on various substrates, several indicators were calculated. Among these wettability indicators, the water PMF (potential of mean force) has the most correlation tendency with interfacial water molecular orientation than depletion layer width and droplet contact angle. The results reveal that the aggregation of argon molecules on substrates not only depending on the level of hydrophobicity but also determined by the competition between gas-solid and water-solid interaction as well as water molecular structure near the surface. In addition, the surface nanobubble is always observed coexisted with the gas enrichment layer. The water structure adjacent to water-gas and water-solid interfaces also plays an important factor in gas out-flux and gas aggregation, respectively. The quasi-2D simulation shows that only a slight difference in the curved argon-water interface from the plane interface which suggests no noticeable obstructing effect on gas outflux from the gas-water interfacial water networks.

Keywords: gas aggregation, interfacial nanobubble, molecular dynamics simulation, wettability

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Authors: Dahi Ghareab Abdelsalam Ibrahim

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Scanning interferometry is commonly used for measuring the three-dimensional profiling of surfaces. Here, we used a scanning stage calibrated with standard gauge blocks to measure a standard step height of 200μm. The stage measures precisely the envelope of interference at the platen and at the surface of the step height. From the difference between the two envelopes, we measured the step height of the sample. Experimental measurements show that the measured value matches well with the nominal value of the step height. A light beam of 532nm from a Tungsten Lamp is collimated and incident on the interferometer. By scanning, two envelopes were produced. The envelope at the platen surface and the envelope at the object surface were determined precisely by a written program code, and then the difference between them was measured from the calibrated scanning stage. The difference was estimated to be in the range of 198 ± 2 μm.

Keywords: optical metrology, digital holography, interferometry, phase unwrapping

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Authors: Yu-Che Cheng, Min-Lih Chang, Ke-Hao Cheng, Chuan-Cheng Wang

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Taiwan is an island located along the southeastern coast of the Asian continent, located between Japan and the Philippines. It is surrounded by the sea on all sides. However, due to the presence of the Central Mountain Range, the rivers on the east and west coasts of Taiwan are relatively short. This geographical feature results in a phenomenon where, despite having rainfall that is 2.6 times the world average, 58.5% of the rainwater flows into the ocean. Moreover, approximately 80% of the annual rainfall occurs between May and October, leading to distinct wet and dry periods. To address these challenges, Taiwan relies on large reservoirs, storage ponds, and groundwater extraction for water resource allocation. It is necessary to construct water treatment facilities at suitable locations to provide the population with a stable and reliable water supply. In general, the construction of a new water treatment plant requires careful planning and evaluation. The process involves acquiring land and issuing contracts for construction in a sequential manner. With the increasing severity of global warming and climate change, there is a heightened risk of extreme hydrological events and severe water situations in the future. In cases of urgent water supply needs in a region, relying on traditional lengthy processes for constructing water treatment plants might not be sufficient to meet the urgent demand. Therefore, this study aims to explore the use of simplified water treatment procedures and the construction of rapid "temporary water treatment plants" to tackle the challenges posed by extreme climate conditions (such as a century-long drought) and situations where water treatment plant construction cannot keep up with the pace of water source development.

Keywords: temporary water treatment plant, emergency water supply, construction site groundwater, drought

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Authors: Kun Huang

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This paper investigates whether the combination of local and stochastic volatility models can be calibrated exactly to any arbitrage-free implied volatility surface of European option. The risk neutral Brownian Bridge density is applied for calibration of the leverage function of our Hybrid model. Furthermore, the tails of marginal risk neutral density are generated by Generalized Extreme Value distribution in order to capture the properties of asset returns. The local volatility is generated from the arbitrage-free implied volatility surface using stochastic volatility inspired parameterization.

Keywords: arbitrage free implied volatility, calibration, extreme value distribution, hybrid model, local volatility, risk-neutral density, stochastic volatility

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Authors: Pradeep Lamichhane, Nima Pourali, E. V. Rebrov, Volker Hessel

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Nitrogen fixation is critical for plants for the biosynthesis of protein and nucleic acid. Most of our atmosphere is nitrogen, yet plants cannot directly absorb it from the air, and natural nitrogen fixation is insufficient to meet the demands. This experiment used a fast-modulated surface-confined atmospheric pressure plasma created by a 6 kV (peak-peak) sinusoidal power source with a repetition frequency of 68 kHz to fix nitrogen. Plasmas have been proposed for excitation of nitrogen gas, which quickly oxidised to NOX. With different N2/O2 input ratios, the rate of NOX generation was investigated. The rate of NOX production was shown to be optimal for mixtures of 60–70% O2 with N2. To boost NOX production in plasma, metal oxide catalysts based on TiO2 were coated over the dielectric layer of a reactor. These results demonstrate that nitrogen activation was more advantageous in surface-confined plasma sources because micro-discharges formed on the sharp edges of the electrodes, which is a primary function attributed to NOX synthesis and is further enhanced by metal oxide catalysts. The energy-efficient and sustainable NOX synthesis described in this study will offer a fresh perspective for ongoing research on green nitrogen fixation techniques.

Keywords: nitrogen fixation, fast-modulated, surface-confined, sustainable

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Authors: Akulov M. A., Orlova O. R., Zaharov V. O., Tomskij A. A.

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Introduction: One of the common postoperative complications of posterior cranial fossa (PCF) and cerebello-pontine angle tumor treatment is a facial nerve palsy, which leads to multiple and resistant to treatment impairments of mimic muscles structure and functions. After 4-6 months after facial nerve palsy with insufficient therapeutic intervention patients develop a postparalythic syndrome, which includes such symptoms as mimic muscle insufficiency, mimic muscle contractures, synkinesis and spontaneous muscular twitching. A novel method of treatment is the use of a recent local neuromuscular blocking agent– botulinum toxin A (BTA). Experience of BTA treatment enables an assumption that it can be successfully used in late facial nerve palsy complications to significantly increase quality of life of patients. Study aim. To evaluate the efficacy of botulinum toxin A (BTA) (Xeomin) treatment in patients with late facial nerve palsy complications. Patients and Methods: 31 patients aged 27-59 years 6 months after facial nerve palsy development were evaluated. All patients received conventional treatment, including massage, movement therapy etc. Facial nerve palsy developed after acoustic nerve tumor resection in 23 (74,2%) patients, petroclival meningioma resection – in 8 (25,8%) patients. The first group included 17 (54,8%) patients, receiving BT-therapy; the second group – 14 (45,2%) patients continuing conventional treatment. BT-injections were performed in synkinesis or contracture points 1-2 U on injured site and 2-4 U on healthy side (for symmetry). Facial nerve function was evaluated on 2 and 4 months of therapy according to House-Brackman scale. Pain syndrome alleviation was assessed on VAS. Results: At baseline all patients in the first and second groups demonstrated аpostparalytic syndrome. We observed a significant improvement in patients receiving BTA after only one month of treatment. Mean VAS score at baseline was 80,4±18,7 and 77,9±18,2 in the first and second group, respectively. In the first group after one month of treatment we observed a significant decrease of pain syndrome – mean VAS score was 44,7±10,2 (р<0,01), whereas in the second group VAS score was as high as 61,8±9,4 points (p>0,05). By the 3d month of treatment pain syndrome intensity continued to decrease in both groups, but, the first group demonstrated significantly better results; mean score was 8,2±3,1 and 31,8±4,6 in the first and second group, respectively (р<0,01). Total House-Brackman score at baseline was 3,67±0,16 in the first group and 3,74±0,19 in the second group. Treatment resulted in a significant symptom improvement in the first group, with no improvement in the second group. After 4 months of treatment House-Brockman score in the first group was 3,1-fold lower, than in the second group (р<0,05). Conclusion: Botulinum toxin injections decrease postparalytic syndrome symptoms in patients with facial nerve palsy.

Keywords: botulinum toxin, facial nerve palsy, postparalytic syndrome, synkinesis

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Authors: Z. Mazrouei-Sebdani, A. Khoddami, H. Hadadzadeh, M. Zarrebini

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Silica aerogels are well-known meso-porous materials with high specific surface area (500–1000 m2/g), high porosity (80–99.8%), and low density (0.003–0.8 g/cm3). However, the silica aerogels generally are highly brittle due to their nanoporous nature. Physical and mechanical properties of the silica aerogels can be enhanced by compounding with the fibers. Although some reports presented incorporation of the fibers into the sol, followed by further modification and drying stages, no information regarding the aerogel powders as filler in the polymeric fibers is available. In this research, waterglass based aerogel powder was prepared in the following steps: sol–gel process to prepare a gel, followed by subsequent washing with propan-2-ol, n-Hexane, and TMCS, then ambient pressure drying, and ball milling. Inspired by limited dust releasing, aerogel powder was introduced to the PET electrospinning solution in an attempt to create required bulk and surface structure for the nano fibers to improve their hydrophobic and insulation properties. The samples evaluation was carried out by measuring density, porosity, contact angle, sliding angle, heat transfer, FTIR, BET and SEM. According to the results, porous silica aerogel powder was fabricated with mean pore diameter of 24 nm and contact angle of 145.9º. The results indicated the usefulness of the aerogel powder confined into nano fibers to control surface roughness for manipulating superhydrophobic nanowebs with sliding angle of 5˚ and water contact angle of 147º. It can be due to a multi-scale surface roughness which was created by nanowebs structure itself and nano fibers surface irregularity in presence of the aerogels while a laye of fluorocarbon created low surface energy. The wettability of a solid substrate is an important property that is controlled by both the chemical composition and geometry of the surface. Also, a decreasing trend in the heat transfer was observed from 22% for the nano fibers without any aerogel powder to 8% for the nano fibers with 4% aerogel powder. The development of thermal insulating materials has become increasingly more important than ever in view of the fossil energy depletion and global warming that call for more demanding energy-saving practices.

Keywords: Superhydrophobicity, Insulation, Sol-gel, Surface energy, Roughness.

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Authors: Gyeong-Sung Kim, In-soo Ahn, Yong Cho

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SBR (Sequencing Batch Reactor) process is usually applied to membrane water treatment plants to treat its concentrated wastewater. The role of SBR process is to remove COD (Chemical Oxygen Demand) and NH3 from wastewater before discharging it outside of the water treatment plant using microorganism. Microorganism’s nitrification capability is influenced by water temperature because the nitrification rate of the concentrated wastewater becomes ‘zero’ as water temperature approach 0℃. Heating system is necessary to operate SBR in winter season even though the operating cost increase sharply. The operating cost of SBR at ‘D’ RO water treatment plant in Korea was 51.8 times higher in winter (October to March) compare to summer (April to September) season in 2014. Otherwise the effluent water temperature maintained around 8℃ constantly in winter. This study focuses on application heat pump system to recover the thermal energy from the effluent water of ‘D’ RO plant so that the operating cost will be reduced.

Keywords: water treatment, water thermal energy, energy saving, RO, SBR

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Authors: Boonsri Lertviriyachit

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The objective of this research is to investigate the treatment of psoriasis through Thai traditional medicine in the selected areas of 2 east coast provinces; Samudprakarn Province and Chantaburi Province. The informants in this study were two famous and accepted Thai traditional doctors, who have more than 20 year experiences. Data were collected by in depth interviews and participant-observation method. The research instrument included unstructured interviews, camera, and cassette tape to collect data analyzed by descriptive statistics. The results revealed that the 2 Thai traditional doctors were 54 and 85 years old with 25 and 45 years of treatment experiences. The knowledge of Thai traditional medicine was transferred from generations to generations in the family. The learning process was through close observation as an apprentice with the experience ones and assisted them in collecting herbs and learning by handling real case in individual situations. Before being doctors, they had to take exam to get the Thai traditional medical certificate. Knowledge of being Thai traditional doctors included diagnosis and find to the suitable way of treatment. They have to look into disorder physical fundamental factors such as blood circulation, lymph, emotion, and food consumption habit. It is important that the treatment needs to focus on balancing the fundamental factors and to observe contraindication.

Keywords: Thai traditional medicine, psoriasis, Samudprakarn Province, Chantaburi Province

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Authors: Luvindran Sugumaran, Mohd Nashrul Mohd Zubir, Kazi Md Salim Newaz, Tuan Zaharinie Tuan Zahari, Suazlan Mt Aznam, Aiman Mohd Halil

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Due to the rapid advancement of integrated circuits and the increasing trend towards miniaturizing electronic devices, the amount of heat produced by electronic devices has consistently exceeded the maximum limit for heat dissipation. Currently, the two-phase cooling technique based on phase change pool boiling heat transfer has received a lot of attention because of its potential to fully utilize the latent heat of the fluid and produce a highly effective heat dissipation capacity while keeping the equipment's operating temperature within an acceptable range. There are numerous strategies available for the alteration of heating surfaces, but to find the best, simplest, and most dependable one remains a challenge. Lately, surface texturing via laser ablation has been used in a variety of investigations, demonstrating its significant potential for enhancing the pool boiling heat transfer performance. In this research, the nucleate pool boiling heat transfer performance of laser-textured copper surfaces of different patterns was investigated. The bare copper surface serves as a reference to compare the performance of laser-structured surfaces. It was observed that the heat transfer coefficients were increased with the increase of surface area ratio and the ratio of the peak-to-valley height of the microstructure. Laser machined grain structure produced extra nucleation sites, which ultimately caused the improved pool boiling performance. Due to an increase in nucleation site density and surface area, the enhanced nucleate boiling served as the primary heat transfer mechanism. The pool boiling performance of the laser-textured copper surfaces is superior to the bare copper surface in all aspects.

Keywords: heat transfer coefficient, laser texturing, micro structured surface, pool boiling

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Authors: Dawid Stawski, Silviya Halacheva, Dorota Zielińska

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The surface properties of many materials can be readily and predictably modified by the controlled deposition of thin layers containing appropriate functional groups and this research area is now a subject of widespread interest. The layer-by-layer (lbl) method involves depositing oppositely charged layers of polyelectrolytes onto the substrate material which are stabilized due to strong electrostatic forces between adjacent layers. This type of modification affords products that combine the properties of the original material with the superficial parameters of the new external layers. Through an appropriate selection of the deposited layers, the surface properties can be precisely controlled and readily adjusted in order to meet the requirements of the intended application. In the presented paper a variety of anionic (poly(acrylic acid)) and cationic (linear poly(ethylene imine), polymers were successfully deposited onto the polypropylene nonwoven using the lbl technique. The chemical structure of the surface before and after modification was confirmed by reflectance FTIR spectroscopy, volumetric analysis and selective dyeing tests. As a direct result of this work, new materials with greatly improved properties have been produced. For example, following a modification process significant changes in the electrostatic activity of a range of novel nanocomposite materials were observed. The deposition of polyelectrolyte nanolayers was found to strongly accelerate the loss of electrostatically generated charges and to increase considerably the thermal resistance properties of the modified fabric (the difference in T50% is over 20°C). From our results, a clear relationship between the type of polyelectrolyte layer deposited onto the flat fabric surface and the properties of the modified fabric was identified.

Keywords: layer-by-layer technique, polypropylene nonwoven, surface modification, surface properties

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Authors: Victor Emery David Jr, Md S. Hossain

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Sewage sludge management has been a problem faced by most developing cities as in the case of Monrovia. The management of sewage sludge in Monrovia is still in its infant stage. The city is still struggling with poor sanitation, clogged pipes, shortage of septic tanks, lack of resources/human capacity, inadequate treatment facilities, open defecation, the absence of clear guidelines, etc. The rapid urban population growth of Monrovia has severely stressed Monrovia’s marginally functional urban WSS system caused by the civil conflict which led to break down in many sectors as well as infrastructure. The sewerage system which originally covered 17% of the population of Monrovia was down to serving about 7% because of bursts and blockages causing backflows in other areas. Prior to the Civil War, the average water production for Monrovia was about 68,000 m3/day but has now dropped to about 10,000 m3/day. Only small parts of Monrovia currently have direct access to the piped water supply while most areas depend on trucked water delivered to community collection points or household tanks, and/or on water from unprotected dug wells or hand pumps. There are only two functional treatment plants; The Fiamah Treatment plant and the White Plains Treatment Plant.

Keywords: Fiamah Treatment plant, management, Monrovia/Montserrado County, sewage, sludge

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Authors: Neel K. Shah

Abstract:

Passive flow control on aerofoils has largely been achieved through the use of protrusions such as vane-type vortex generators. Consequently, innovative flow-control concepts should be explored in an effort to improve current component performance. Therefore, experimental research has been performed at The University of Manchester to evaluate the flow-control effectiveness of a vortex generator made in the form of a surface indentation. The surface indentation has a trapezoidal planform. A spanwise array of indentations has been applied in a convergent orientation around the maximum-thickness location of the upper surface of a NACA-0015 aerofoil. The aerofoil has been tested in a two-dimensional set-up in a low-speed wind tunnel at an angle of attack (AoA) of 3° and a chord-based Reynolds number (Re) of ~2.7 x 105. The baseline model has been found to suffer from a laminar separation bubble at low AoA. The application of the indentations at 3° AoA has considerably shortened the separation bubble. The indentations achieve this by shedding up-flow pairs of streamwise vortices. Despite the considerable reduction in bubble length, the increase in leading-edge suction due to the shorter bubble is limited by the removal of surface curvature and blockage (increase in surface pressure) caused locally by the convergent indentations. Furthermore, the up-flow region of the vortices, which locally weakens the pressure recovery around the trailing edge of the aerofoil by thickening the boundary layer, also contributes to this limitation. Due to the conflicting effects of the indentations, the changes in the pressure-lift and pressure-drag coefficients, i.e., cl,p and cd,p, are small. Nevertheless, the indentations have improved cl,p and cd,p beyond the uncertainty range, i.e., by ~1.30% and ~0.30%, respectively, at 3° AoA. The wake measurements show that turbulence intensity and Reynolds stresses have considerably increased in the indented case, thus implying that the indentations increase the viscous drag on the model. In summary, the convergent indentations are able to reduce the size of the laminar separation bubble, but conversely, they are not highly effective in reducing cd,p at the tested Reynolds number.

Keywords: aerofoil flow control, laminar separation bubbles, low Reynolds-number flows, surface indentations

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Authors: Emrah Caylak

Abstract:

The aim of this study is to investigate the effect of iron therapy on oxidative stress, ghrelin, and nesfatin-1 levels in patients with iron deficiency anemia (IDA). Thirty patients who applied to Internal Medicine Clinic and were diagnosed with IDA and also 30 healthy individuals as a control were included in the study. The samples were collected from IDA patients before and after treatment. Differences in serum MDA, TAC, and plasma ghrelin, nesfatin-1 were analyzed among the three groups. Serum MDA and TAC levels were found higher and lower in IDA patients before the treatment group compared to the controls (p < 0.05). After the iron therapy, plasma acylated ghrelin and nesfatin-1 levels in IDA patients were found higher in IDA patients before the treatment group and controls (p < 0.05). Plasma ghrelin and nesfatin-1 levels increase with iron treatment in IDA patients. The iron therapy induces the synthesis of ghrelin and nesfatin-1 in human body, thus causes increased appetite and food intake.

Keywords: anemia, oxidative stress, ghrelin, nesfatin-1

Procedia PDF Downloads 139

Authors: Elkington Sibusiso Mnguni

Abstract:

In South Africa, mining has been a key economic sector since the discovery of gold in 1886 in the Witwatersrand region, where the city of Johannesburg is located. However, some mines have since been decommissioned, and the continuous pumping of acid mine drainage (AMD) also stopped causing the AMD to rise towards the ground surface. This posed a serious environmental risk to the groundwater resources and river systems in the region. This paper documents the development and extent of the environmental damage as well as the measures implemented by the government to alleviate such damage. The study will add to the body of knowledge on the subject of AMD treatment to prevent environmental degradation. The method used to gather and collate relevant data and information was the desktop study. The key findings include the social and environmental impact of the AMD, which include the pollution of water sources for domestic use leading to skin and other health problems and the loss of biodiversity in some areas. It was also found that the technical intervention of constructing a plant to pump and treat the AMD using the high-density sludge technology was the most effective short-term solution available while a long-term solution was being explored. Some successes and challenges experienced during the implementation of the project are also highlighted. The study will be a useful record of the current status of the AMD treatment interventions in the region.

Keywords: acid mine drainage, groundwater resources, pollution, river systems, technical intervention, high density sludge

Procedia PDF Downloads 182

Authors: A. Giwa, S. M. Jung, W. Fang, J. Kong, S. W. Hasan

Abstract:

MnO₂ nanowires were developed as filtration media for wastewater treatment that uniquely combines several advantages. The resulting material demonstrated strong capability to remove the pollution of heavy metal ions and organic contents in water. In addition, the manufacture process of such material is practical and economical. In this work, MnO₂ nanowires were integrated with the state-of-art bio-electrochemical system for wastewater treatment, to overcome problems currently encountered with organic, inorganic, heavy metal, and microbe removal, and to minimize the unit footprint (land/space occupation) at low cost. Results showed that coupling the bio-electrochemical with MnO₂ resulted in very encouraging results with higher removal efficiencies of such pollutants.

Keywords: bio-electrochemical, nanowires, novel, wastewater

Procedia PDF Downloads 377

Authors: Seok-Tae Yoon, Jae-Yeong Choi, Gyu-Mok Jeon, Yong-Jin Cho, Jong-Chun Park

Abstract:

Conventional submarines obtain propulsive force by using an electric propulsion system consisting of a diesel generator, battery, motor, and propeller. In the underwater, the submarine uses the electric power stored in the battery. After that, when a certain amount of electric power is consumed, the submarine floats near the sea water surface and recharges the electric power by using the diesel generator. The voyage carried out while charging the power is called a snorkel, and the high-temperature exhaust gas from the diesel generator forms a heat distribution on the sea water surface. The heat distribution is detected by weapon system equipped with thermo-detector and that is the main cause of reducing the survivability of the submarine. In this paper, an experimental study was carried out to establish optimal operating conditions of a submarine for reduction of infrared signature radiated from the sea water surface. For this, a hot gas generating system and a round acrylic water tank with adjustable water level were made. The control variables of the experiment were set as the mass flow rate, the temperature difference between the water and the hot gas in the water tank, and the water level difference between the air outlet and the water surface. The experimental instrumentation used a thermocouple of T-type to measure the released air temperature on the surface of the water, and a thermography system to measure the thermal energy distribution on the water surface. As a result of the experiment study, we analyzed the correlation between the final released temperature of the exhaust pipe exit in a submarine and the depth of the snorkel, and presented reasonable operating conditions for the infrared signature reduction of submarine.

Keywords: experiment study, flow rate, infrared signature, snorkeling, thermography

Procedia PDF Downloads 347

Authors: J. Hrabovský, M. Chabičovský, J. Horský

Abstract:

Water spray cooling is a technique typically used in heat treatment and other metallurgical processes where controlled temperature regimes are required. Water spray cooling is used in static (without movement) or dynamic (with movement of the steel plate) regimes. The static regime is notable for the fixed position of the hot steel plate and fixed spray nozzle. This regime is typical for quenching systems focused on heat treatment of the steel plate. The second application of spray cooling is the dynamic regime. The dynamic regime is notable for its static section cooling system and moving steel plate. This regime is used in rolling and finishing mills. The fixed position of cooling sections with nozzles and the movement of the steel plate produce nonhomogeneous water distribution on the steel plate. The length of cooling sections and placement of water nozzles in combination with the nonhomogeneity of water distribution leads to discontinued or interrupted cooling conditions. The impact of static and dynamic regimes on cooling intensity and the heat transfer coefficient during the cooling process of steel plates is an important issue. Heat treatment of steel is accompanied by oxide scale growth. The oxide scale layers can significantly modify the cooling properties and intensity during the cooling. The combination of the static and dynamic (section) regimes with the variable thickness of the oxide scale layer on the steel surface impact the final cooling intensity. The study of the influence of the oxide scale layers with different cooling regimes was carried out using experimental measurements and numerical analysis. The experimental measurements compared both types of cooling regimes and the cooling of scale-free surfaces and oxidized surfaces. A numerical analysis was prepared to simulate the cooling process with different conditions of the section and samples with different oxide scale layers.

Keywords: heat transfer coefficient, numerical analysis, oxide layer, spray cooling

Procedia PDF Downloads 402