Performance Analysis of Photovoltaic Module with Different Passive Cooling Methods

This paper analyses the difference in terms of performance of passive cooling systems for photovoltaic (PV) modules. The objective of this paper is to identify which passive cooling systems offers the best results in reducing the operating temperature and improving the generation of output power. The performance of photovoltaic (PV) module will gradually decrease as the operating temperature increases. The energy from the sun’s photons are not enough to knock out the electrons from the atom to generate more electricity. That being the case, two passive cooling systems is developed which is the cotton wick structures with water and aluminium fins were attached to the back side of the photovoltaic (PV) module. The cotton wick structures with water utilises the capillary action of the water to extract excess heat from the module while the aluminium fins act as a heat sink that can remove heat from module to the adjacent air. Results showed that the cooling systems managed to enhance the output power by an average of 3.94% for the module with cotton wick structures with water while an average of 2.67% increment for the module under aluminium fin mounted as the cooling system.

Experimental Study on Fire Sources for Full-Scale Fire Testing of Simple Sprinkler Systems Installed in Multiplexes

Fires are accidents that can cause numerous human casualties in multiplexes. The simple sprinkler systems applied in South Korea employ sprinklers to protect people against residential fires, as specified by the National Fire Protection Association (NFPA) standard 13D. Therefore, it is necessary to evaluate the fire control performance of multiplexes, which are at a greater risk than residential facilities. This study aims to verify the fire control performance of simple sprinklers in multiplexes and to develop a fire source that can be used as a protocol for testing fire suppression methods. The fire source was evaluated by using a 3 MW large-scale calorimeter (ISO 13784). The proposed fire source for multiplexes was applied in various forms according to the application methods, with ignition sources including cotton wick, wood crib, and heptane, and then the fire tests were conducted.

Improving the Lifetime Efficiency of Trimedlure-Dispensing System in Trapping the Fruit Fly Ceratitis capitata Using Polyethylene Matrix

Detection of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), is highly reliant on traps loaded with trimedlure (TML), a male-specific attractant. The successful application of attractants requires that constituents are placed in a suitable dispensing system to reduce volatilization and increase the effective field longevity of the attractant. A series of trials were conducted in different fruit orchards to test 1) the efficiency of a polyethylene-matrix plug in regulating the emission rate of TML 2) and the lifetime attractiveness of the plug compared to the cotton wick dispenser. Cotton dispensers containing the recommended dose of TML (0.75 cm3) and with a double dose (1.5 cm3) remained active for 6 and 8 wk, respectively. The increase in TML dose from 0.75 cm3 to 1.5 cm3 led to an increase in the longevity of the cotton dispenser, but there was no significant difference between the doses in biological activity. In all trials, TML-polyethylene matrix dispensers were more efficient under field conditions as they attracted more males for up to 12 wk and prolonged the release of TML more than the cotton wick dispensers. The TML-loaded polyethylene matrix dispensers might be useful in 1) minimizing the losses of the liquid TML from cotton wicks, 2) avoiding the damage that occurs when using other dispensers, 3) prolonging the TML lifetime in the field through regulating its release rates, 4) potentially minimizing the adverse effect of high temperatures on release rate, and, finally, 5) minimizing the costs of using large amounts of expensive TML solutions.

POPULATION FLUCTUATION OF ADULT MALES OF THE FRUIT FLY, Bactrocera tau Walker (DIPTERA: TEPHRITIDAE) IN PASSION FRUIT ORCHARDS IN RELATION TO ABIOTIC FACTORS AND SANITATION

Fruit fly (Bactrocera tau) is the most destructive pest on some fruits in Indonesia. Monitoring of the pest population is essential as one of the procedures in the IPM concept. The study aimed to investigate the seasonal fluctuation of adult males of B. tau and their damage on passion fruits in relation to abiotic factors. The research was done by a survey method on three plots of passion fruit orchards in Alahan Panjang, West Sumatra, Indonesia from March to December 2005. In plot 1 the farmer practiced sanitation by removing damaged fruits and weeds from the orchard. In the plots 2 and 3 no sanitation was practiced. Each plot was 1 ha in size. The parameters observed were density of adult male B. tau and climatic factors (rainfall per day, number of rainy days, and average day temperature). Empty mineral water bottle traps were used to catch adult males of B. tau. Each plot had 16 traps set up with cue lure as fruit fly attractant. Each trap was baited with 3 ml cue lure on a cotton wick (1 cm diameter). The cotton wick was rebaited at 2-week intervals. The traps were placed on host plants about 1.5 m above the ground. Trapped flies were collected every two weeks and counted. The data were analyzed by correlation analysis. The results revealed that the number of male B. tau<br />in three orchards showed a similar fluctuation during the study period with a major peak in July. The lower numbers of flies captured in plot 1 (with sanitation) compared to the two other plots (without sanitation) were consistent with a lower percentage of damaged fruits in the plot 1 compared to the other two. The percentage of damaged fruits gradually decreased over time to about 20% in plot 1 which is lower than that in the other two<br />plots (30-40%). The number of fruit flies captured with cue lure baited traps correlated positively with all three abiotic factors studied. The seasonal fluctuation of the fruit fly population and the damage to the fruits are necessary to be studied as a procedure<br />in IPM for controlling B. tau.

POPULATION FLUCTUATION OF ADULT MALES OF THE FRUIT FLY, Bactrocera tau Walker (DIPTERA: TEPHRITIDAE) IN PASSION FRUIT ORCHARDS IN RELATION TO ABIOTIC FACTORS AND SANITATION

Fruit fly (Bactrocera tau) is the most destructive pest on some fruits in Indonesia. Monitoring of the pest population is essential as one of the procedures in the IPM concept. The study aimed to investigate the seasonal fluctuation of adult males of B. tau and their damage on passion fruits in relation to abiotic factors. The research was done by a survey method on three plots of passion fruit orchards in Alahan Panjang, West Sumatra, Indonesia from March to December 2005. In plot 1 the farmer practiced sanitation by removing damaged fruits and weeds from the orchard. In the plots 2 and 3 no sanitation was practiced. Each plot was 1 ha in size. The parameters observed were density of adult male B. tau and climatic factors (rainfall per day, number of rainy days, and average day temperature). Empty mineral water bottle traps were used to catch adult males of B. tau. Each plot had 16 traps set up with cue lure as fruit fly attractant. Each trap was baited with 3 ml cue lure on a cotton wick (1 cm diameter). The cotton wick was rebaited at 2-week intervals. The traps were placed on host plants about 1.5 m above the ground. Trapped flies were collected every two weeks and counted. The data were analyzed by correlation analysis. The results revealed that the number of male B. tau<br />in three orchards showed a similar fluctuation during the study period with a major peak in July. The lower numbers of flies captured in plot 1 (with sanitation) compared to the two other plots (without sanitation) were consistent with a lower percentage of damaged fruits in the plot 1 compared to the other two. The percentage of damaged fruits gradually decreased over time to about 20% in plot 1 which is lower than that in the other two<br />plots (30-40%). The number of fruit flies captured with cue lure baited traps correlated positively with all three abiotic factors studied. The seasonal fluctuation of the fruit fly population and the damage to the fruits are necessary to be studied as a procedure<br />in IPM for controlling B. tau.

Effect of benzyladenine (BA) on auxin-induced stem elongation and thickening in tulip (Tulipa gesneriana L.)

It is well known that stem elongation in tulip is induced by the auxin produced in the leaves and gynoecium. Excision of the flower bud and all the leaves in an early stage of tulip growth resulted in almost total inhibition of stem growth, but the inhibition was completely recovered by the exogenous application of auxin to the place from which the flower bud had been removed. Hormonal control of stem thickening in tulip is much less known. Additional application of benzyladenine (BA) to the tulip stem by soaking a cotton wick wrapped around all the internodes only slightly inhibited stem growth induced by IAA at a concentration of 0.1 and 2.0%, but substantially stimulated the thickening of all the internodes. The treatment of the tulip stem with benzyladenine enabled direct contact of the cytokinin with the epidermis, which is an important factor in stem elongation. The experiment conducted in field conditions also showed that BA only slightly inhibited the elongation of the fourth internode induced by IAA, but stimulated the thickening of that internode. IAA applied at a concentration of 2.0% stimulated ethylene production to a much higher extent than IAA at a concentration of 0.1%, and BA affected the auxin-induced ethylene production only to a small extent. Metabolic significance of these findings is discussed.

A Cotton Wick Improves Hearing in a Patient with Profound Hearing Loss

Dear Editor, The tympanic membrane and the ossicular chain contribute roughly 28 dB in hearing gain. In chronic suppurative otitis media, loss of tympanic membrane and lysis of the ossicular chain are significant causes of hearing loss.1 Through the years, hearing impairment has been augmented using various devices such as ear trumpets, carbon hearing aids, vacuum tube and transistor hearing aids, bone anchored hearing aids, and cochlear implants.2 This case report describes how a cotton wick was used to amplify sound. Case Report A 65-year-old man consulted for hearing loss. He had a childhood history of recurrent ear discharge and hearing loss and was diagnosed with chronic suppurative otitis media. At age 55, he underwent tympanomastoidectomy of the left ear. While surgery stopped the left ear discharge, there was complete hearing loss in this ear. For this reason, he opted not to have surgery on the right ear. There was subsequent recurrent ear disease of the right ear. He would clean his ear with a cotton wick and apply antibiotic drops during bouts of ear discharge. He observed that leaving the ear wick with a few drops of topical otic preparations (polymyxin-neomycin-steroid or ofloxacin) would lessen the frequency of ear discharge and improve his hearing. He found that morning application and positioning of the cotton wick in his right ear using tweezers and a toothpick allowed him to hear adequately to conduct his daily activities as an architect. (Figure 1, 2) The fear of hearing loss from another surgery, cost of a commercial hearing aid, and great utility of a simple cotton wick made him continue his practice for these ten years. Examination of the right middle ear without the cotton wick showed thickened mucosa, absent malleus and incus structures, a patent Eustachian tube and a near – total tympanic membrane perforation. There was no keratinous material or foul smelling discharge. (Figure 3) Pure tone audiometry confirmed that with the cotton wick, the right air-bone gap decreased at 500 hz, 1kHz, 2Kh and 4KHz by 30db, 40dB, 35dB and 25dB respectively. (Table 1) DISCUSSION At different anatomic levels, mechanical sound energy is amplified and transmitted to the functional parts of the ear. The tympanic membrane and oval window ratio of 21:1 and malleus-incus lever mechanism ratio of 1.3:1 provide a 28 dB amplification of conductive hearing.1 This gain is reflected by frequency specific air-bone gaps, which can range between 25-40 dB. With the contribution from the external ear, the overall conductive gain is 60 dB.1,3 Damage to the auditory system often results in a loss of hearing sensitivity that is frequency – specific. The presence of a frequency – specific wide air-bone gap suggests ossicular chain discontinuity among patients with chronic otitis media.4 Narrowing of the air-bone gap, which in this case was provided by insertion of the cotton wick, may lead to at least partial restoration of ossicular coupling. The ability of the cotton wick to improve hearing may be attributed to its possession of characteristics for sound conduction and acoustic impedance, such as stiffness, resistance and mass. The effectiveness of the cotton wick was reported to be dependent on its positioning in the ear; the patient would have to insert the wick down to the level of the promontory or oval window, occasionally blow his nose, or reposition the cotton wick to achieve an acceptable hearing level. However, for a patient with completely deaf contralateral ear, a 32.5 dB gain in hearing is very pronounced and significant. The hearing gain produced by the cotton wick only amplified the air conductive component of hearing but not bone conduction. While it afforded amplification of sound and a route of medicine administration, it may also have contributed to sensorineural hearing loss brought about by ototoxicity of medications and thickening of the oval and round window from chronic irritation. For this reason, utmost caution must be advised before considering use of a “cotton wick” to amplify hearing in this manner-- a practice we do not endorse. The cotton wick may have served as a vibrating piston on top of the oval window which amplified hearing. Such a mechanism may conceivably prognosticate potential gain from a contemplated tympanoplasty in the same way that the “paper patch test”5 predicts simple myringoplasty outcomes. Having said that, the diagnostic utility of such a cotton wick requires further investigation before potential clinical applications such as prognostication of tympanoplasty are theorized. Could future studies show that a preoperative cotton wick (or equivalent device) may approximate potential gains from a good tympanoplasty with ossiculoplasty in a patient with total tympanic perforation and ossicular chain loss? Sincerely, Ryner Jose D. Carrillo, MD, MSc Precious Eunice R. Grullo, MD, MPH Maria Luz M. San Agustin, RN, MClinAudio