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The natural soiling of photovoltaic cover glass has recently been shown to include both an inorganic and organic particulate matter. Under favorable growth conditions, the latter can lead to the growth of dense colonies of filamentous fungi, which potentially leads to measurable performance losses over time. Herein, we report on a field study where glass coupon samples were deployed in soiling-prone locations, which focused on Dubai (United Arab Emirates) and Mumbai (India). For each site location, clear differences in the soiling were observed. The samples from Mumbai were contaminated with an abundance of filamentous fungi, whereas the samples from Dubai had primarily inorganic contamination. The effectiveness of soiling mitigation strategies, which include cleaning techniques and glass coatings, are discussed in detail.

Conventional topical delivery in hyperacute bacterial conjunctivitis and endophthalmitis is associated with low drug bioavailability due to rapid precorneal clearance. Hence, in the present investigation, an attempt has been made to enhance ocular bioavailability of tobramycin sulfate by formulating drug-loaded microparticles dispersed in thermosensitive in situ gel.Microparticles prepared by emulsion-ionic gelation technique were characterized for drug loading, entrapment efficiency, particle size, surface morphology, and in vitro drug release. Consequently microparticles (F2 prepared with 1.5%w/v chitosan, 0.2%w/v tripolyphosphate, and drug, 30%w/w of polymer) with high drug loading and encapsulation efficiency were dispersed in thermosensitive in situ gel containing poloxamer 407 and varying percentage of chitosan. In situ gel containing drug-loaded microparticles were evaluated for gelation temperature, rheological behavior, mucoadhesive strength, in vitro drug release, in vitro permeation, ocular irritation, and bioavailability in aqueous humor of rabbits.Formulation containing 17%w/v poloxamer 407 and 0.5%w/v chitosan (P2) gelled at 32°C ± 1.5°C gave pseudoplastic behavior. In vitro permeability of tobramycin from the formulation P2 was found 2-folds greater than eye drops. It also gave significantly higher aqueous humor concentration of tobramycin compared with eye drops with no signs of ocular irritation.Thus, the formulation possesses high potential for treating ocular infections.

A methodology to analyse the annual energy losses due to soiling of solar PV modules is developed. It is based on the actual soiling rates observed in Mumbai over a 5 year period, andalso on PV system simulations using PVSyst. The impact of different cleaning cycles is also investigated. The impact of module performance degradation on the energy output is also investigated. The developed methodology is applied to a single string system over a 11 year period from 2000 to 2010. It is found that the long term degradation would be the dominant loss process for reasonable cleaning frequencies of once in 42 days. This methodology can be applied to other locations, provided the locations have predictable weather patterns.

The natural soiling of photovoltaic cover glass has recently been shown to include both inorganic and organic particulate matter. Under favorable growth conditions, the latter can lead to the growth of dense colonies of filamentous fungi, potentially leading to measurable performance losses over time. Herein, we report on a field study where glass coupon samples were deployed in soiling-prone locations, focusing on Dubai (United Arab Emirates) and Mumbai (India). For each site location, clear differences in the soiling were observed. The samples from Mumbai were contaminated with an abundance of filamentous fungi whereas the samples from Dubai had primarily inorganic contamination. The effectiveness of soiling mitigation strategies, including cleaning techniques and glass coatings, are discussed in detail.

Evaluation of soiling loss on PV modules based on field measurements is usually a time consuming and expensive undertaking. A laboratory technique using acetonitrile as a carrier solvent is being discussed in the literature. In this work a low-cost artificial dust deposition technique using water as carrier solvent is presented. Dust samples deposited using the two carrier solvents were compared using FTIR analysis, as well as the short circuit current and spectral losses in solar cells overlaid with soiled glass. Acetonitrile is seen to modify the chemical composition of the dust substantially. The uniformity of dust deposited using water is seen to be adequate for systematic analysis of the impact of soiling on PV modules. Acetonitrile based deposition is seen to overestimate the losses.

Evaluation of soiling loss on photovoltaic (PV) modules in a geographical location involves collecting data from a fielded PV system of that location. This is usually a time-consuming and expensive undertaking. Hence, we propose collecting dust samples from various location of interest, preferably from the module surface, and use them as dust samples so that the soiling experiments can be conducted in the laboratory. In this work, a low-cost artificial dust deposition technique is utilized that could be used to deposit dust on a module surface in a controlled manner, which helps in predicting soiling loss associated with various dust properties, including densities, chemical compositions, and particle sizes. The soil samples covering diverse climatic conditions and six different geographic locations covering all of India were collected and investigated. Soiling loss on a silicon solar cell with Mumbai dust (17.1%) is about two times that of Jodhpur dust (9.8%) for the same soil gravimetric density of 3 g/m(2). The dust collected from Mumbai showed the highest spectral loss, followed by Pondicherry, Agra, Hanle, Jodhpur, and Gurgaon. The worst affected module technology was amorphous silicon (17.7%), followed by cadmium telluride (15.7%), crystalline silicon (15.4%), and CIGS (14.5%) for the same density (1.8 g/m(2)) of dust from Mumbai.

Dust or soot from the air causes significant losses in the PV modules. Evaluating the performance loss of photovoltaic modules in a location involves collecting data from a fielded PV system. This is usually a time consuming and a costly affair. Hence we propose collection of dust from an area, preferably from the module surface, and use it as dust sample so that the soiling experiments can be conducted in laboratories. Here a low-cost artificial dust deposition technique is introduced that could be used to deposit dust on a module surface in a controlled manner which would help to predict the soiling loss associated with various dust densities. This approach produced uniform soil coatings of various densities. Using the test dust we have deposited dust of varying densities which showed short-circuit current loss ranging from 4% to 49%. Dust from different parts of India was deposited using this technique to obtain uniform dust density of 0.25mg/cm2. It was found that the dust from Agra showed highest soiling loss, followed by dust samples from Hanle, Jodhpur and Gurgaon. It was observed that dust samples from Agra and Gurgaon showed higher response in the wavelength range of 900 - 1100nm as compared to Hanle and Jodhpur.