A Facile, Fast, and Low-Cost Method for Fabrication of Micro/Nano-Textured Superhydrophobic Surfaces

Background Alkyl ketene dimer (AKD) is frequently used in paper industry as an inexpensive sizing agent. The formation of a fractal structure after curing the solidified AKD for an extra-long time (4 - 6 days) results in superhydrophobicity. In this study, a facile and low-cost method was utilized to turn AKD’s surface superhydrophobic in a very short period of time. Method We fabricated a superhydrophobic layer by dipping glass and paper substrates in molten AKD and then treating them with ethanol after solidification. The samples were characterized by X-ray diffraction, Scanning electron microscopy, Fourier transform-infrared spectroscopy, X-ray photoelectron spectroscopy, Confocal laser scanning microscopy, and dynamic contact angle goniometry. Results The results show that briefly treating the coatings, obtained from isothermally heated AKD melt at 40°C for 3 min, with ethanol leads to superhydrophobicity with an advancing and receding contact angle of 158.7±1.4° and 156.8±0.9°, respectively. By increasing the melt temperature to 70°C and heating time to 6 h followed by ethanol treatment, the advancing and receding contact angles increased to 163.7±1.3° and 162.6±1.2°, respectively. Conclusions This enhancement in superhydrophobicity is due to the formation of entangled irregular micro/nano textures that create air cushions on the surface resulting in droplet state transition from Wenzel to Cassie. In this method, ethanol can be used several times, and the energy consumption becomes very low. Based on the other techniques in this field, our method has eliminated the complex equipment and procedure applied in the fabrication of a superhydrophobic AKD.https://scholarscompass.vcu.edu/gradposters/1072/thumbnail.jp

Visible Light Driven Photocatalysis for Degradation of Diclofenac

Diclofenac (DCF), a widely used non-steroidal anti-inflammatory drug (NSAID), is a commonly detected substance that readily accumulates in tissues of aquatic fish and poses a threat to wildlife and freshwater quality. Advanced Oxidation Processes (AOPs) have been explored as an alternative method for complete mineralization of DCF as conventional treatment methods are inadequate for treatment of trace contaminants. This study employs a semi-batch, swirl-flow, monolithic type photocatalytic reactor to determine intrinsic kinetic parameters of DCF mineralization, in an immobilized system under both UV and visible radiation. The goal of this work to determine true kinetics of DCF, after correcting for external mass transfer resistance that exists when catalysts is immobilized, as a function of various operating parameters such as flow rate, catalyst loading, pH, light intensity, initial concentration, and photocatalyst type. This study also utilized an innovative method of solar-activation of TiO2 using Eosin-Y dye for the degradation of DCF. Furthermore, the study incorporated a central composite design (CCD) to optimize the dye concentration and estimated the cost for the present process. Optimized parameters for light intensity (750 mW/cm2), Eosin-Y dye concentration (2 mg/L), TiO2 loading (37.5 mg/cm2) and DCF concentration (25 mg/L) were determined by means of a CCD study. A cost estimation for the materials used for the current process was also performed. It was determined that the additional cost of using 4 ppm instead of 2 ppm to achieve only 10% more DCF degradation is not warranted and would require additional treatment to remove subsequently formed halogenated compounds. In the last part of this thesis, in order to determine mechanism of degradation of DCF, intermediate products were identified. 22 different intermediate products were found during the visible light photocatalytic degradation of DCF using EY-sensitized TiO2 at the optimized conditions. Out of the 22 intermediates, 19 of the transformed products were identified. Toxicity analysis of the treated and untreated samples of DCF were also assessed. The treated samples indicated an increase in toxic effect to Daphnia magna compared to the untreated DCF solution. The objective and significant contribution of this study lies in (1) obtaining true kinetic data independent of reactor types, (2) incorporation CCD to optimize the reaction operating parameters, (3) cost estimation of the present process, and (4) identification and toxicity analysis of DCF intermediates formed during the optimized process

Pattern Project - The Great Peanut Dream

The Pattern Project explores the process of developing visual patterns, intended for the built interior environment, through both hand and digital crafts. Inspirations evolve into pattern concepts that inform message and intention. The intended message then informs motif, color, density, composition, line, repetition, hierarchy, and texture. Drawing from history, designers assess the role of pattern within the built environment and its connection to architecture and building occupants. Traditional handcrafts have evolved and are now used in contemporary processes while new digital crafts have emerged as pattern-making tools. The patterns developed through the Pattern Project were produced to scale on paper or textile measuring approximately 24 wide x 60 long.https://scholarscompass.vcu.edu/pp/1002/thumbnail.jp

Accommodating the Muslim Women Privacy (Hijab) Requirements with Ventilation Needs in Malaysian Terrace Houses

There is a conflict in the design of a tropical house when it comes to ventilation and privacy requirements. This situation is seen more acute in modern terrace houses in Malaysia. This study seeks to find a layout guideline that balances between the required ventilation and female privacy in Malaysian terrace houses. The Islamic principles have been discussed to find out the privacy requirements. The result shows that the privacy has different degrees, and spaces of a house can be divided into three separate areas: public area, semi-private area and private area. The principles of planning for building in tropical climate have been discussed to find out ventilation requirements. Iranian traditional rural and urban houses have been studied to analyze how privacy and ventilation were considered in their design and to observe if these results could be applied to Malaysian houses. A study of the traditional and typical housing types of Malaysian terrace houses had been done to analyze the adaptation to privacy and ventilation. The result shows that terrace houses could not provide complete privacy and some factors of traditional adaptation can be applied in new terrace house designs. A case study was conducted to evaluate the preferences of Malay women for privacy and to find the visual and physical space relationship in the house. The result indicates that terrace houses are not designed according to Malay women preferences. The result of the study shows that it is possible to have a suitable layout that balances between the required ventilation and the female privacy in Malaysian terrace houses by considering a review and rearrangement of terrace house unit floor

Smartphone Loss Prevention System Using BLE and GPS Technology

Being an all-in-one gadget, smartphones play a vital role in our everyday lives. However, millions of people suffer every year by losing their phones. A lost phone creates a huge security threat and data loss possibility to the users. Some preventive measures are available to protect from unauthorized access. Moreover, there are some post-loss solutions to track down, retrieve data from a lost locked phone, and protect the privacy and security of lost phone data, but those have some drawbacks as well. Considering the situation, our proposed system offers a preventive solution which will protect the smartphones from getting lost. Our system involves a smartwatch which will be connected to smartphone via Bluetooth Low Energy (BLE) and keep track of the distance between the smartphone and the smartwatch worn by user in real-time. The system will be able to identify if the distance goes beyond 20 feet or a customizable distance given by the user and immediately raise an alert in the smartwatch, creating vibration and sound in public places. The system allows users to mark their safe location (e.g., house, office) and radius where their smartphone will be safe, and they don’t need alerts. We have developed 3 different models to implement this system with different approaches using Ranging, Haversine formula and Geofencing. For our work, we aim to perceive how accurate our models are in terms of calculating distance and safe location tracking as well as alert response time and models impact on battery life of both smartphone and smartwatch. We have developed an Android application and a smartwatch application that run on both smartwatch and smartphone for each model and compared their performances based on our evaluation parameters. We conducted experiments under various real-world conditions and the system incorporated with Model 1 can generate alert with 96% accuracy when user is away from the smartphone beyond the threshold distance in an unsafe location. This affordable solution will ensure prevention from smartphones getting lost in public places in an effective way securing confidentiality and data protection to users

Epidural analgesia in labour and its outcome

INTRODUCTION: Until this last century, labour pain had been exemplified as a traumatic and miserable event in a women’s life. Various methods have been tried since time immemorial to alleviate this pain. However, this endeavour did not receive much support till the late 19th century, because of various medical and religious reasons. Labour is a complex mixture of biological mechanisms with mixed emotions and pain .People believed that this labour pain had lot of biological significance and an attempt to abolish it would be potentially dangerous to both mother and fetus and would alter uterine contractions and prolong the delivery. Later there was a breakthrough for this in 1853, when Sir John Snow anaesthetized queen Victoria with chloroform for the delivery of her 8th baby prince Leopold , She later said "Dr Snow administered the blessed chloroform and its effect was calming and relaxing beyond measure". “Childbirth has been recognized as among the most painful experiences known”, (melzak and his colleagues) have reported that after spending 15 years studying the physiology of pain, and of applying the Mc Gill Questionnaire as a comparative measure of the intensity of naturally occurring and artificially provoked pain-and the effectiveness of the technique of analgesia-they undertook a study on labour pain .They concluded that the pain of labour was the most severe they had assessed, thus making obstetrical analgesia highly in demand today. Numerous strategies either non-pharmacologic e.g., Hypnosis, Transcutaneous nerve stimulation, Acupuncture, Abdominal decompression, Yoga, parenteral drugs, Inhalational analgesics, Obstetric blocks or epidural blockade are considered to tackle this pain. Studies suggest that providing pain relief has positive impact on both mother and fetus and the outcome of labour. Out of all the analgesic methods tried ACOG suggests that “Epidural block is the most effective and least depressant (pharmacologic option) allowing for an alert mother”. Epidural analgesia is highly popular in west. In India, it’s still not much popularized due to unfamiliarity, and inexpert personals. The mother should know well before term, how she will be accommodated during labour and what will be done to achieve a safe and pleasant delivery. The mother must be encouraged to express her preference regarding posture, analgesia and mobility. Fear of the un known is more dreadful than fear of the known, and fear or anxiety in labour is equally as detrimental to both mother and fetus as is pain in labour. AIM OF THE STUDY: To study the effects of epidural analgesia on labour, maternal and neonatal outcome. To compare the efficacy and side effects of epidural analgesia with that of intramuscular pethidine. OBJECTIVES: 1. To compare the efficacy of both intramuscular pethidine and epidural analgesia. 2. To compare the duration of labour in both the groups after the administration of the drug. 3. To compare the normal vaginal delivery rate to instrumental and caesarean delivery rate in both the groups. 4. To compare the maternal haemodynamic status ,maternal satisfaction and pain score. 5. To compare the intrapartum and postpartum complications if any. 6. To analyze the maternal and fetal side effects in both the groups. MATERIALS AND METHODS: The study was conducted in the department of Obstetrics and Gynaecology, PSG Institute of Medical Science and Research, Coimbatore. Study Design: Prospective randomized controlled trial. Study Population: Study group consists of two groups. Each group has 100 antenatal mothers in labour. Inclusion Criteria: Singleton pregnancy with vertex presentation, Pregnancy complicated by • hypertensive disorders of pregnancy, • Respiratory diseases. Exclusion Criteria: • Bleeding diathesis, • Local and systemic sepsis, • Central nevous system disorders, • Previous caeserian section, • Multiple pregnancy, • Mal presentations, • History of hypersensitivity to the drug, • Chronic musculoskeletal disease of the lumbo sacral region, • Mother not willing to use the drug. STATISTICAL ANALYSIS: The statistical analysis was performed using the statistical software SPSS 16.0. Descriptive analyses were performed by the calculation of minimum, maximum median and percentages. The continuous variables were analyzed using the Mann-Whitney U test and categorical data were compared using a Pearson χ2 test or Fisher’s exact test, depending on the data meeting assumptions. Significance was defined as P<0.05. SUMMARY: This study was done in PSG Institute of Medical Science and Research, Coimbatore in the Department of Obstetrics and Gynaecology. Primary aim of the study was to study the effect of epidural analgesia on labour, maternal and neonatal outcome. Seconadary aim was to compare the efficacy and side effects of epidural analgesia and intramuscular pethidine. Total number of patients enrolled for the study was 200. These 200 consecutive patients were alternatively assigned to epidural analgesia and parenteral pethidine in their active phase of labour. Thus each study group had 100 patients. Detailed history and examination of the patient was done and a base line CTG was taken. Once the patient gets in to active labour she was randomly allocated into either epidural analgesic group or intramuscular pethidine group. Vital parameters, fetal heart rate and uterine contractions were monitored following administration of the drug ,every 5 minutes for 60 minutes following loading dose completion and every 30 minutes thereafter until delivery. Labour was augmented with oxytocin and any side effects or complications during the study period was noted. The observations noted were as follows: • Age, parity and gestational age were not statistically different in both the groups. • Pain score was assessed which showed significant less pain for patients in epidural group when compared to pethidine group (p<0.001). • Cervical dilatation at the time of administration of drug was not statistically different (P>0.05). • We could not found any significant difference (P=0.729) in the time interval from administration of drug to full dilatation of cervix. (The mean rank of Epidural and Pethidine were 99.12 and 101.88 respectively. The Mann –Whitney U =4862.5 and P=0.729) • Duration of second stage of labour was also not significantly different (P=0.152) in these two groups. • Rate of instrumental deliveries was found to be more with epidural group (38%) vs. (13%) in pethidine group, with significant statistical difference (p<0.001). The major indication of instrumental delivery in Epidural group was failed maternal effort, which could be because of perineal relaxation and motor block. • There was no significant difference in the rate of caesarean section between the study groups (P=0.8711). • Mode of placental separation and post partum complications were not statistically different with (P =0.121) and (P=0.297) respectively. • In our study APGAR score at 1minute and 5 minute in Epidural and Pethidine group showed statistically significant difference (P= 0.0335) and (P=0.008) respectively ,showing better APGAR for babies born after epidural analgesia. NICU admissions in the two groups also showed no significant difference (P=0.1165). • 77% of patients in epidural group had no complication during the study period. Incidence of Dural puncture, fever and motor blockade were 2%, incidence of head ache and tachycardia were 4% and 9% patients complained of urinary retention. In pethidine group 30 % patients complained of vomiting; sedative effect of the drug was also significantly more with pethidine group. CONCLUSION: Labour analgesia strives at making child birth a less traumatic and providing a more comfortable zone for a mother to welcome her baby .To make this remarkably possible we should adopt the best possible technique which yields excellent analgesia with minimal side effects on both mother and baby. The inference of our study shows that analgesia provided by lumbar epidural analgesia is remarkably better than parenteral pethidine, at the same time duration of first, second and third stage of labour, placental separation, post partum complications ,rate of caeserian delivery were all comparable between the two groups. Parenteral pethidine is still a good option for analgesia in poor resource setting or in conditions where epidural analgesia is contraindicated

Comparative Study of the Rates of Dispersal of Triadica sebifera (Chinese Tallow) and Imperata Cylindrica (Japanese Blood Grass) in North America

Chinese Tallow (Triadica sebifera) and Japanese Blood Grass (Imperata cylindrica) are two invasive species that wreck havoc on their invaded areas by reducing the biodiversity of their new environments. We studied the rate of dispersal of these two species in North America to determine which species spreads faster. We hypothesized that Chinese Tallow spreads faster than Japanese Blood Grass since Chinese Tallow was introduced in North America long before Japanese Blood Grass and has a greater number of seed dispersal methods (e.g. wind, water, bird, etc.) than Japanese Blood Grass. To test our hypothesis, we collected the record of Chinese Tallow and Japanese Blood Grass in North America from their year of introduction to present and determined the area covered by each species individually over time. After comparing the range covered by the two species over time, we observed that though Chinese Tallow spread faster in its early years, yet in sum, Japanese Blood Grass spreads faster than Chinese Tallow, which opposes our hypothesis. For the log transformed total range difference of Japanese Blood Grass subtracted by Chinese Tallow 70-120 years after introduction, our equation for the trendline was y= =-0.0302*x + 3.39 with an R^2 value of 0.934. This negative slope evident from the trendline refutes our initial hypothesis. For the data analysis, our t=-5.31, d.f=2, p(one-tailed)=.016842. Based on our experiment, it was clear that the rate of dispersal of the Japanese Blood Grass in North America is increasing at an alarming rate and it is necessary to control this species as it is extremely harmful for the environment and biodiversity. As our data showed that the rate of dispersal of the Chinese Tallow is decreasing, the management methods for the Chinese Tallow can be studied to find effective ways to control the Japanese Blood Grass

Batteries and Supercapacitors for Electric Vehicles

International audienceDue to increasing gas prices and environmental concerns, battery propelled electric vehicles (BEVs) and hybrid electric vehicles (HEVs) have recently drawn more attention. In BEV and HEV configurations, the rechargeable energy storage system (RESS) is a key design issue [1–3]. Thus, the system should be able to have good performances in terms of energy density and power capabilities during acceleration and braking phases. However, the thermal stability, charge capabilities, life cycle and cost can be considered also as essential assessment parameters for RESS systems.Presently batteries are used as energy storage devices in most applications. These batteries should be sized to meet the energy and power requirements of the vehicle. Furthermore, the battery should have good life cycle performances. However, in many BEV applications the required power is the key factor for battery sizing, resulting in an over-dimensioned battery pack [4,5] and less optimal use of energy [4]. These shortcomings could be solved by combination of battery system with supercapacitors [6–8]. In [9], it is documented that such hybridization topologies can result into enhancing the battery performances by increasing its life cycle, rated capacity, reducing the energy losses and limiting the temperature rising inside the battery. Omar et al. concluded that these beneficial properties are due to the averaging of the power provided by the battery system [4,6,9]. However, the implementation of supercapacitors requires a bidirectional DC–DC converter, which is still expensive. Furthermore, such topologies need a well-defined energy flow controller (EFC). Price, volume and low rated voltage (2.5–3 V) hamper the combination of battery with supercapacitors [6,10]. In order to overcome these difficulties, Cooper et al. introduced the Ultra-Battery, which is a combination of lead-acid and supercapacitor in the same cell [11]. The new system encompasses a part asymmetric and part conventional negative plate. The proposed system allows to deliver and to absorb energy at very high current rates. The Ultra-Batteries have been tested successfully in the Honda Insight. However, this technology is still under development. In the last decade, a number of new lithium-ion battery chemistries have been proposed for vehicular applications. In [12–15], it is reported that the most relevant lithium-ion chemistries in vehicle applications are limited to lithium iron phosphate (LFP), lithium nickel manganese cobalt oxide (NMC), lithium nickel cobalt aluminum oxide (NCA), lithium manganese spinel in the positive electrode and lithium titanate oxide (LTO) in the negative electrode. In this chapter, the performance and characteristics of various lithium-ion based batteries and supercapacitor will be evaluated and discussed. The evaluation will be mainly based on the electrical behavior. Then the characteristics of these RESS systems will be investigated based on the electrical and thermal models

Comparative analysis of optimal power flow in renewable energy sources based microgrids

Adaptation of renewable energy is inevitable. The idea of microgrid offers integration of renewable energy sources with conventional power generation sources. In this research, an operative approach was proposed for microgrids comprising of four different power generation sources. The microgrid is a way that mixes energy locally and empowers the end-users to add useful power to the network. IEEE-14 bus system-based microgrid was developed in MATLAB/Simulink to demonstrate the optimal power flow. Two cases of battery charging and discharging were also simulated to evaluate its realization. The solution of power flow analysis was obtained from the Newton–Raphson method and particle swarm optimization method. A comparison was drawn between these methods for the proposed model of the microgrid on the basis of transmission line losses and voltage profile. Transmission line losses are reduced to about 17% in the case of battery charging and 19 to 20% in the case of battery discharging when system was analyzed with the particle swarm optimization. Particle swarm optimization was found more promising for the deliverance of optimal power flow in the renewable energy sources-based microgrid