Water generation from atmospheric air by using different composite desiccant materials

In this communication, new composite desiccant materials having 37% concentration of CaCl₂ have been compared for water production from atmospheric air. The vermiculite–saw wood, jute and burnt-clay have been used as host materials and CaCl₂ as a hygroscopic salt. All the desiccant materials have been tested with the solar glass desiccant box type system (SGDBS) with a collector area of 0.36?m². Design parameters for water production are: height of the glass from the desiccant bed to be 0.22?m, an inclination angle of 30°, the effective thickness of the glass as 3?mm and the number of glazing is single. It has been found that on the experimental day, the maximum amount of fresh water generated by the vermiculite–saw wood/CaCl₂ is 130?ml/kg/day.     

Comparative Performance of Different Sector Arrangement in a Desiccant Wheel Using a Mathematical Model

A one‐dimensional mathematical model has been used for a three‐sector desiccant wheel (two sectors with purge) with different flow arrangements. The model considers both gas and solid side resistance and shows a good agreement with experimental results. This model has been used to conduct a comparative performance analysis in both the effective adsorption and effective regeneration sector of a desiccant wheel. It was found that an effective regeneration sector gives better results for the performance parameters (rotation of wheel, regeneration temperature, velocity, and ambient moisture) as compared to an effective adsorption sector. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.21103     

Fabrication of portable solar thermal bank for indoor cooking

The aim of this report is to build a portable solar thermal bank based on a Scheffler reflector that is capable of boiling-type cooking using HITEC as a thermal storage material. This report reviews the problems related to solar cooking and evaluates the novel layout of a portable solar thermal bank which includes a daily thermal storage vessel. This stove is in the shape of a cylindrical container filled with phase-changing latent heat storage material. Inside the container, we provide a small gap taking into account the volumetric expansion of the phase change material (PCM) during the melting process. The solar thermal bank is charged in the sun. It is placed directly for a few hours under the focus of a Scheffler reflector, which charges the solar thermal bank with enough thermal energy stored. After a while, the cooking process can be completed by users using that stored heat. The top cavity is used as a cooking pot in a solar thermal bank. Cooking meals do not require direct sunlight, which is typical for most solar cookers. The portable solar thermal bank is an alternative for low-income households and adapts to local traditions of indoor cooking. It is portable and can be used safely to cook indoors or outdoors. In this study, a solar cooker with a thermal storage device was developed using a PCM. The size of the stove has been calculated by calculating the energy consumption for two to three people. HITEC salt has been chosen as a phase change material for thermal storage, which will be used for cooking when there is no sunlight. It enhances the applicability of solar cooking and preserves cooking possibilities using energy stored throughout the day at low production costs.     

Dielectric behavior of perovskite glass ceramics

The recent developments of energy storage devices are concerned with larger energy storage ability, low loss and good temperature stability. It has a great technological importance in engineering science. The dielectric materials like ceramics and glass ceramics have great interest in electronic ceramic industry due to above concern. The ceramic dielectrics are used as a capacitive element in electronic circuits. The perovskite glass ceramics have very high dielectric constant and low dielectric loss. The high dielectric constant in glass ceramics is attributed to space charge polarization. In order to produce glass ceramics of high dielectric constant, barium titanate glass ceramics is the first discovered ferroelectric perovskite. In this review article, we are summarizing the dielectric behavior of perovskite glass ceramics such as BaTiO₃, SrTiO₃, PbTiO₃, (Ba,Sr)TiO₃ and (Pb,Sr)TiO₃.     

Experimental investigation of a desiccant dehumidifier based on evacuated tube solar collector with a PCM storage unit

A rotary desiccant dehumidifier based on an evacuated tube solar air collector with a phase change material (PCM) storage unit has been experimentally investigated. The PCM (acetamide) simultaneously stores and transfers the heat to the air during day hours. The stored heat of the PCM is utilized to produce hot air during night hours. The performance of the system is analyzed for different air flow rates at different rotational speeds (rph) of desiccant wheel. The dehumidification effectiveness (?_A), regeneration effectiveness (?_R), and dehumidification coefficient of performance are 8.17, 10.35, and 0.0327%, respectively, at 16 rph of the desiccant wheel with 127.23?kg/h air flow rate. The system is also used to generate dry air for 14?h a day with PCM, which shows that acetamide used as the PCM has an ability to store an adequate amount of heat to regenerate the desiccant wheel during off-sunshine hours.     

Energy-Aware WBAN for Health Monitoring Using Critical Data Routing (CDR)

Wireless Personal Communications - Wireless body area network (WBAN) is the subfield of Wireless Sensor Network, employs in the area of monitoring the health of the patient. WBAN is also known as...     

Iontophoresis for drug delivery into the nail apparatus: exploring hyponychium as the site of delivery

In present studies, a hyponychium pathway (from ventral side of the nail plate) was investigated as a potential route of drug delivery into the nail apparatus using iontophoresis as an active physical method. In vitro transport studies were performed across the human nail plate using sodium fluorescein as a marker substrate for 24?h. After transport studies, the amount of sodium fluorescein extracted from an active diffusion area of the nail plate in case of iontophoresis was found to be ～54-folds more to that of passive. The amount of sodium fluorescein retained in the peripheral area of the nail plate after application of iontophoresis was found to be ～30-folds more relative to passive. Ex vivo transport studies were performed on excised human cadaver toe using terbinafine hydrochloride as a model drug for three days (8?h/day). The amount of terbinafine retained in the nail plate after application of iontophoresis (3.43?±?1.34?µg/mg) was ～20-folds more when compared with passive (0.17?±?0.10?µg/mg). The amount of drug extracted from the nail bed and nail matrix was 1.73?±?0.12?µg/mg and 0.55?±?0.22?µg/mg, respectively. On the other hand, there was no detectable amount of terbinafine found in the nail bed and nail matrix in case of control (passive delivery). These studies show that the iontophoretic drug delivery through hyponychium region to other parts of the nail apparatus could be a potential way of onychomycosis treatment.     

Successive relaxor ferroelectric behavior in La modified (Ba,Sr)TiO3 borosilicate glass ceramics

In the present investigation, we are reporting the successive ferroelectric relaxor behavior of (Ba,Sr)TiO₃ borosilicate glass ceramics. The ferroelectric relaxor nature of the present glass ceramics is attributed to structural phase transition from the rhombohedral to orthorhombic to tetragonal to cubic. A very high value of dielectric constant was found to be 89,684 at 100 Hz in glass ceramic sample 64[(Ba_0.7Sr_0.3)TiO₃]–30[2SiO₂–B₂O₃]–5[K₂O]–1[La₂O₃], BST5K1L0.3S831 and such large value may be due to space charge polarization in glassy matrix. The various contribution in polarization processes are confirmed by impedance spectroscopic analysis.     

Second law analysis of the 160 Wp standalone solar photovoltaic system

The demand for solar photovoltaic (SPV) systems is growing all over the world due to the continuous increase in the cost of conventional means of power. India has the advantage of around 300 clear sunny days in a year. However, the biggest problem is conversion efficiency. In this paper, an attempt has been made for evaluating the second law efficiency of 160?Wp stand-alone SPV systems installed in RKGIT Ghaziabad premises. The performance of a SPV system depends on climate conditions like temperature, air velocity and a number of sunny days. The solar energy striking the solar panels gets converted into electric and thermal energy. In this work, we have considered the effect of ambient temperature and air velocity on the efficiency of solar panels. The average second law efficiency of SPV systems was found to be 10.7%, whereas maximum second law efficiency was 13.8% at 9am on the same day. The efficiency of the SPV system can be improved by maintaining the temperature of the module.     

Numerical and experimental investigation of operating parameters of solar–powered desiccant wheel in India

A mathematical model has been used to predict the operating parameters of a desiccant wheel for performance analysis of the desiccant wheel. The model considered both gas and solid side resistance. The model shows a good agreement with experimental data. An experimental setup was fabricated using an evacuated tube solar air collector with a desiccant wheel. The hot air needed for regeneration is produced by the evacuated tube solar air collector, which has a collector surface area of 4.44 m² . The regeneration can be started from 40 °C. The temperature of outlet air obtained is in the range of 40–65 °C in this evacuated tube solar air collector. The experimental setup was installed at NIT Kurukshetra, India, 29° 58′ (latitude) North and 76° 53′ (longitude) East. Numerical results showed that both the moisture removal and the temperature increment of the process air increases with an increasing regeneration air temperature, regeneration air inlet velocity, and process inlet moisture. But both the moisture removal and the temperature increment of the processed air decreases by increasing the process air inlet velocity and regeneration air moisture at the inlet. © 2012 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.21031