Small Fan Research Articles

Initial observations of water quality indicators in the unconfined shallow aquifer in Dili City, Timor-Leste: suggestions for its management

The management of groundwater quality is a critical issue in developing nations where sanitation and drinking water targets are commonly addressed by facilitating access to groundwater, which is then managed as a common-pool resource. We investigate the quality of the shallow unconfined groundwater in Dili’s alluvial fan system, which 50% of Dili’s rapidly growing population use for all their water requirements. Using the basic chemical and microbiological analyses that are locally available (sulfate, total hardness, fluoride, manganese, iron, ammonia, nitrite, nitrate, total coliform and E. coli) we show that the shallow wells commonly contain enhanced concentrations of dissolved solids and microbiological contaminants (total coliform and E. coli), relative to deeper wells. Cool, shallow wells are worse than warm equivalents. Elevated nitrate and nitrite pollution in the embassy district are tentatively attributed to affluence factors, such as lawn cultivation and water filtration equipment. Microbiological contamination, and associated manganese contamination of groundwater, mimic population patterns, but are concentrated in the finer grained sediments of the small fans and low-slope interdistributary areas. We suggest that rapid development and successful implementation of appropriate sanitation policy in Dili (and elsewhere) is required to address the problematic features of the shallow groundwater system. Success will be predicated on (1) the establishment of baseline data, and (2) development of a systems-thinking approach to holistic water resource management.

On the analysis of heat haze effects with spacetime DIC

Long image series (i.e., movies) can be analyzed via digital image correlation (DIC) techniques. A new spacetime implementation is introduced to extend instantaneous DIC with minimal implementation complexity. With this procedure, a denoised reference image is built considering a series of more than 200 images. Such spacetime approach is very interesting when high temperature experiments are performed since it provides a very effective temporal regularization. The analysis of heat haze effects is carried out on a thermomechanical test in which the sample made of ceramic matrix composite is subjected to temperatures greater than 1200 °C in the heat affected zone of the laser beam. It is shown that the addition of a small fan reduces the spurious displacement fluctuations.

A multidisciplinary approach to estimate slip rate-magnitude and recurrence time for a segment of a major active fault. Case study: The Agua Blanca Fault, Valle de Agua Blanca, B.C., México

The segmented major Agua Blanca Fault is one of the largest geologically active faults in northern Baja California, México. It extends 130 km inland, from the Pacific Ocean to the San Matías Pass (near the Gulf of California). Geologic evidence shows that the Agua Blanca Fault has been active during most of the Quaternary. To estimate the seismic hazard that the Agua Blanca Fault represents for the region, it is necessary to recognize its seismic activity. However, seismic data and historical registries of major seismic events associated to this fault are limited. In addition, structural evidence required to calculate the slip rates is scarce. Thus, in order to determine fault movements and hence its seismic risk, it was necessary to use other geological techniques. For that reason, a different multidisciplinary approach to estimate slip rates, magnitude and recurrence times for a geologically active major fault was tested in a selected segment of the Major Agua Blanca Fault (study area: Valle de Agua Blanca, locality: Rancho La Cocina-Rancho Agua Blanca). In this case, correlation of the major alluvial fans displaced by the fault by the use of the clast counting technique and other geological data was used in order to estimate slip rates, magnitude and recurrence times for the Valle de Agua Blanca segment of the fault. By using this method, two major distinctive ancient fans and four small recent fans dissected and offset by the fault within the Valle de Agua Blanca were identified. Fault displacement was established, and the slip rate was calculated to be ∼6 mm/yr consistent with the amount obtained in other studies within the area by the use of other techniques. The average length of each segment of the Agua Blanca Fault is between 20 and 30 km, a surface rupture of 20–30 km accompanies earthquakes of Ms 6.7–7.0. This is the case in the Valle Agua Blanca, which is the boundary between two major eastern fault segments 20–35 km long. These lengths, and the slip rate obtained, and using the Bonilla et al., (1984) regression relationship developed for worldwide strike-slip faults, we can estimate the recurrence interval for earthquakes with magnitudes between 6 and 7. The recurrence interval for earthquakes with Ms = 6 to 7 generated by the Agua Blanca Fault in the Valle Agua Blanca is between 75 and 200 yr, with average ground displacements of 0.5–1.25 m.

Rapid alluvial sedimentation aided expansion of Moissac during the High Middle Ages along the Tarn River in southern France

We examine medieval urban expansion of Moissac, a town located at the outlet of the Tarn River basin draining 15,400 km2 in southern France, in order to understand the association of Moissac's expansion to river position and sedimentation patterns in the river valley. A chronostratigraphic framework was derived from three auger holes and an archaeological excavation using radiocarbon dating and standard field and laboratory characterization of sediments. Five radiocarbon dates were obtained from one auger hole, along with particle size, magnetic susceptibility, organic matter, and quantitative soil color analyses to augment field descriptions. Results indicate Moissac spawned from the Abbey of Saint-Pierre on the apex of a small alluvial fan surrounded by backswamps ca. 850 CE, and urban growth radiated down the fan toward the river bottomlands throughout the following several centuries. At ca. 1000–1200 CE, human-induced soil erosion in the watershed caused very rapid aggradation of surrounding alluvial backswamps (at long-term average sedimentation rates of 20–30 mm/y). Such rapid bottomland accretion probably was driven by rampant agricultural soil erosion linked with wet climatic periods and enhanced flooding. This bottomland accretion enabled urban expansion and agricultural activities to cover the former backswamp and wetlands by the late Middle Ages (ca. 1300–1500 CE). Although we normally associate human-induced soil erosion with negative consequences of ecosystem services, the rapid bottomland accretion and resulting habitable and arable land can be viewed as a positive ecosystem service outcome resulting from human-induced soil erosion.

Consideration of modern sendimentary processes of the Evros river delta front and prodelta, NE Aegean sea

Gravity cores data from the Evros River delta front and prodelta confirm the aspect that the Evros River deltaic deposits tend to west-northwest, along the main direction of the local hydrodynamic regime, preventing the construction of a symmetrical Holocene prism. In the delta front, the terrigenous sediment consists mostly of fine-grained material. Its vertical succession is monotonous with slight differences in grain size or colour, and lack of internal structure or current-produced laminae, indicating almost immutable sedimentary processes as well as long-term discharge fluctuations. The river-borne sand is limited because of its entrapment in the river mouth but sometimes, during extreme conditions (periods of high river discharge, short-lived catastrophic events etc.), can be transported seawards covering an extensive area of the Alexandroupolis Gulf. The negligible biogenic content and the absence of bioturbation effects are attributed to the high rates of deposition. Some bioturbated horizons are produced when sedimentation rates decrease temporarily. The prodelta sediment distribution patterns occur a distinctive zonation along an east-southeast to westnorthwest trend. In the central part, mud dominates, while on both sides of this area, the content of sand gradually increases and becomes the prevalent facies near the coast and in the outer plateau of the gulf. The vertical facies sequences of the upper sedimentary cover are complicated, with many variations in grain size, colour and biogenic content reflecting a complicated manner of deposition. The major feeder of this area is the Evros River providing great amounts of suspended load. Another remarkable source of sand is derived from the coastline, which during storm conditions provides coarse-grained material in the shoreface area. Finally, a sediment supplier of local importance, Loutros River, affects the eastern area of Alexandroupolis building up a small subaqueous fan. In the open sea, the consequences of the modern sedimentation are negligible. The sandy character of the surface and sub-surface sediments, the analysis of biogenic fragments, the long distance from the present-day terrigenous sources are some evidences which lead to the view that the upper sediment body of the southwestern part of the study area has a presumable relict origin. 210Pb profiles are, more of less, consistent showing a sedimentation rate more than 2 cm/yr in the delta front, which decreases to 0.2 cm/yr at about 8 km seaward.

A forced-convection gas target for the production of [11C]CH4

A forced-convection gas target for the production of [11C]CH4 on a 13 MeV cyclotron was constructed and tested. A small fan was incorporated into the back of the target, which mixes the target gas during irradiation. The effect of the forced convection alone on the target operation and the [11C]CH4 yield was measured. Forced convection improved the target yield by up to 16 ± 4%. In addition, improvement in heat transfer of up to 70% was observed to be a function of fan speed. Operating with forced convection allowed delivery of 21% higher beam currents while still staying in the acceptable pressure rise during irradiation, providing a 25 ± 7% greater yield.

Rebooting Ponies and Men: Discordant Masculinity and the Brony Fandom

In recent years, Brony fandom has grown from a small Internet-based fan community into a pop culture phenomenon complete with large-scale conventions. The appearance of Bronies in mainstream media confounds onlookers because the majority are young adult men celebrating the virtues of candy-colored ponies. This fandom is openly contesting traditional concepts of masculinity, particularly in the United States, by embracing the pony mantra of “love and tolerance.” This theme promotes sharing feelings, acceptance of others, and improving interpersonal relationships. This article seeks to describe some of the characteristics of the fandom and how Bronies are creating a new construction of masculinity called discordant masculinity that steers away from postfeminist trappings in other, “hybrid,” forms of masculinity.

A novel evaporative cooling tower constructed from an inflatable fabric duct

This paper describes a prototype of a novel vertical cooling tower constructed from an inflatable fabric duct that incorporated a water spray nozzle mounted at the top. The device was constructed using two concentric impermeable fabric tubes sealed at either end. It was inflated using a small pressurization fan located at the tower base. A numerical performance model was developed to estimate the downstream conditions of the evaporative cooling tower, and the length necessary for complete evaporation. To test the predictive capability the model of the evaporative cooling tower, experiments were performed under different ambient conditions. The prototype tower did exhibit downdraft cooling. However, the ambient conditions under which the validation measurements were performed were not conducive to achieving a moist air flow that could be measured accurately, and further investigation is recommended.

Who owns the name? Fandom, social inequalities and the contested renaming of a football club in Timişoara, Romania

ABSTRACTRecent scholarship in critical toponymy has raised questions about the impacts on urban residents of selling naming rights and the possibility of contesting the commodification of urban place names. This article examines these issues using Poli Timişoara, the major football team of Timişoara, Romania, as a case study. The cash-strapped local authority sold the naming rights for the team to raise revenue. However, when the club’s private owner was unable to finance the team, the local authority reacquired the naming rights of Poli, now under the name Asociaţia Club Sportiv Poli (a new team with a small fan base). Drawing on the everyday narratives of fans, this article explores how the commodification of a local club name can cause social tensions. This is important for understanding urban residents’ access, or lack thereof, to social capital resources and how this leads to the manifestation of social inequalities which co-determine fans’ reactions and responses to the change in the name of a sports team. The findings suggest that commodifying names can mobilize serious contestations among partisan groups about who owns the name, although such contestations appear to be on uncertain ground because of post-communist urban practices of delayed economic restructuring.

Young, small-scale surface features in Meridiani Planum, Mars: A possible signature of recent transient liquid and gas emissions

Enigmatic small-scale (<1 m) depositional and erosional features found in basaltic sands partly covering bedrock exposures, imaged at several locations in the equatorial Meridiani Planum region by the Mars Exploration Rover Opportunity, may be evidence of previously unrecognized, geologically young (or even contemporary) Martian surface processes. Leveed fissures appear to have formed by venting from beneath; possible explanations include aeolian blowholes near crater margins, volcanic fumarole activity, or gas/vapour escape resulting from the decomposition of small pockets of ground ice, methane clathrates or hydrated sulphate minerals. Some leveed fissures cross-cut and are therefore younger than aeolian ripples thought to have last been active c. 50,000 years ago. Erosional gutters are sharply defined and fresh-looking, internally terraced, sometimes are deeper near one end, and in one case seem to give way to small depositional fans downslope; they have the appearance of having been formed by liquid flow rather than by wind erosion. There is evidence elsewhere that contemporary ground-ice thaw and consequent transient surface run-off may occur occasionally under present conditions at low, near-equatorial latitudes on Mars; short-lived (even for just a few minutes) meltwater emission and flow at the surface could form gutters before evaporating. Further possibilities are the decomposition of buried pockets of methane clathrates (which theoretical considerations suggest might be present and stable even in equatorial regions) giving rise to both methane gas venting and transient surface water, or the release of liquid brines by decomposition of hydrated magnesium sulphate minerals or deliquescence of perchlorates. Dry granular flow mechanisms proposed as explanations for Recurring Slope Lineae seem inadequate to explain the morphologies of leveed fissures and gutters.

Deposition of Bacteria and Bacterial Spores by Bathroom Hot-Air Hand Dryers.

Hot-air hand dryers in multiple men's and women's bathrooms in three basic science research areas in an academic health center were screened for their deposition on plates of (i) total bacteria, some of which were identified, and (ii) a kanamycin-resistant Bacillus subtilis strain, PS533, spores of which are produced in large amounts in one basic science research laboratory. Plates exposed to hand dryer air for 30 s averaged 18 to 60 colonies/plate; but interior hand dryer nozzle surfaces had minimal bacterial levels, plates exposed to bathroom air for 2 min with hand dryers off averaged ≤1 colony, and plates exposed to bathroom air moved by a small fan for 20 min had averages of 15 and 12 colonies/plate in two buildings tested. Retrofitting hand dryers with HEPA filters reduced bacterial deposition by hand dryers ∼4-fold, and potential human pathogens were recovered from plates exposed to hand dryer air whether or not a HEPA filter was present and from bathroom air moved by a small fan. Spore-forming colonies, identified as B. subtilis PS533, averaged ∼2.5 to 5% of bacteria deposited by hand dryers throughout the basic research areas examined regardless of distance from the spore-forming laboratory, and these were almost certainly deposited as spores. Comparable results were obtained when bathroom air was sampled for spores. These results indicate that many kinds of bacteria, including potential pathogens and spores, can be deposited on hands exposed to bathroom hand dryers and that spores could be dispersed throughout buildings and deposited on hands by hand dryers.IMPORTANCE While there is evidence that bathroom hand dryers can disperse bacteria from hands or deposit bacteria on surfaces, including recently washed hands, there is less information on (i) the organisms dispersed by hand dryers, (ii) whether hand dryers provide a reservoir of bacteria or simply blow large amounts of bacterially contaminated air, and (iii) whether bacterial spores are deposited on surfaces by hand dryers. Consequently, this study has implications for the control of opportunistic bacterial pathogens and spores in public environments including health care settings. Within a large building, potentially pathogenic bacteria, including bacterial spores, may travel between rooms, and subsequent bacterial/spore deposition by hand dryers is a possible mechanism for spread of infectious bacteria, including spores of potential pathogens if present.

Determining the Contribution of Ventilation and Insulation of Broiler Breeding Houses in Production Performance Using Analytic Hierarchy Process (AHP)

ABSTRACT This study was conducted using Analytic Hierarchy Process (AHP) in order to rank broiler breeding farms in Zanjan province, Iran, regarding buildings, installations, and equipment to determine their effects on production factors. Data on 108 farms were collected using designed forms. This data was analyzed based on the effectiveness of each parameter in the production and management category according to experts’ opinion. The results indicated that ventilation systems (fans, inlets, and damper) as well as wall and roof insulation in poultry houses, constituted 66% of the technology coefficient. The stocking density increased through improvement of the mechanization coefficient. Most of these farms used longitudinal or tunnel ventilation and a combination of small and large fans. Roof insulation was mostly done using glass wool, and corrugated plastic while installing the heaters outside the poultry house. In these farms, the use of nipple drinkers and plate feeders was more prevalent. Moreover, the results showed that feed conversion and production indices have a significant correlation with mechanization coefficient so that farms with better mechanization coefficients had lower conversion ratio (p=0.04) and higher production indices (p=0.015). In general, the results indicated that ventilation and air inlet systems, as well as wall and roof building technologies have the greatest influence on the mechanization coefficient, while better mechanization coefficients translated into improvements in production efficiency and economic performance of poultry farms.

Improvement of Indoor Air Distribution by Utilizing Small Fans Powered by Solar Energy

A pilot-scale HVAC system is constructed to study the performance of air quality inside the comfort-zone when small fans are utilized to perform the air circulation. The research investigates the impact on energy consumption when the fan of the coil is eliminated from the fan coil unit (FCU). This would improve access to separate comfort zone controls and positively affect thermal comfort in those areas. In the study, the comfort room temperature variation is measured during 15 minutes in four cases, namely: all fans ON, all Fans OFF, 1-Fan ON, and 2-Fans ON. Optimization of the fan location that forces the zone temperature to stabilize around the set-point value in shorter time is recorded. Observation of the results indicates that the position of the fan does affect the time elapsed to reach the set-point as it affects the inside-air turbulence. Comparison of the four cases shows that the All-Fans-ON case cools down the zone temperature faster than other cases in entire space. In return, the space has fluctuated temperature in the cases of the 1-Fan and 2-Fans ON. This is due to the reduction in the turbulence intensity of the air near the Fan(s)-OFF region.

Manufacturing a Refrigerator with Heat Recovery Unit

This study aims to exploite the rejected heating energy from condenser and benefit from it to reheat the foods and other materials. It can also be employed to improve the coefficient of performance of a refrigerator at the same time by using approximately the same consumption electrical energy used to operate the compressor and refrigerator in general. This idea has been implemented by manufacturing of a refrigerator with using additional part has the same metal and condenser pipe diameters but its surface area does not exceed 40% from total surface area of the condenser and its design as an insulated cabinet from all sides to prevent heat leakage through it and located between the compressor and the condenser. Small electrical fan has been added inside this cabinet to provide a suitable air circulation and a homogenous temperature distribution inside the cabinet space. It is expected that the super heating energy of refrigerant (R134a) which comes out of the compressor would be removed inside this cabinet and this insist to condensate the refrigerant (cooling fluid) with a rate higher than that used in the normal refrigerator only. Three magnetic valves have been used in order to control the refrigerant flow in state of operation the refrigerator only or to gather with heating cabinet. To measure the temperatures at each process of the simple vapor compression refrigeration cycle, nine temperature sensors at input and output of each compressor, condenser and an evaporator in additional to input of cabinet and inside it and on evaporator surface have been provided. Five pressure gages have been used to measure the value of pressure and compare it for the two states of operation. The consumption of electrical energy can be calculated by adding an ammeter and a voltmeter and compare between the consumption energy of both states. The obtained results show that there is an improvement in the coeffecient of performance in state of operation the refrigerator with heat recovery cabinet by 20% more than that of the operation of refrigerator only. This improvement is due to the reduction in the condenser exit temperature by 4 to 6 C˚, and the super heat removing process in reheating cabinet. The temperature of the cabinet reachs to 60 C˚ which is a sufficient for the food heating. A small amount of refrigerant pressure reduction due to these additions, and its effect on the preformace of the refrigerator may be not considerable.

A Fan-tastic Quantitative Exploration of Ohm’s Law

Teaching simple circuits and Ohm’s law to students in the introductory classroom has been extensively investigated through the common practice of using incandescent light bulbs to help students develop a conceptual foundation before moving on to quantitative analysis. However, the bulb filaments’ resistance has a large temperature dependence, which makes them less suitable as a tool for quantitative analysis. Some instructors show that light bulbs do not obey Ohm’s law either outright or through inquiry-based laboratory experiments. Others avoid the subject altogether by using bulbs strictly for qualitative purposes and then later switching to resistors for a numerical analysis, or by changing the operating conditions of the bulb so that it is “barely” glowing. It seems incongruous to develop a conceptual basis for the behavior of simple circuits using bulbs only to later reveal that they do not follow Ohm’s law. Recently, small computer fans were proposed as a suitable replacement of bulbs for qualitative analysis of simple circuits where the current is related to the rotational speed of the fans. In this contribution, we demonstrate that fans can also be used for quantitative measurements and provide suggestions for successful classroom implementation.

Rotordynamic Fluid Forces Operates to the Small Axial Fan

Rotordynamic Fluid Forces Operates to the Small Axial Fan

Effect of Number of Blades on Flow Field around Blades of Small Sirocco Fan

Effect of Number of Blades on Flow Field around Blades of Small Sirocco Fan

Effect of Inflow Turbulence to a Small Axial Flow Fan on Fan Noise

Effect of Inflow Turbulence to a Small Axial Flow Fan on Fan Noise

Effect of Flow Field at High Flow Rate on Flow Noise in Small Axial Fan

Effect of Flow Field at High Flow Rate on Flow Noise in Small Axial Fan

Effect of Number of Blades on Flow Fields around Tongue and in Scroll Casing of Small Sirocco Fan

Effect of Number of Blades on Flow Fields around Tongue and in Scroll Casing of Small Sirocco Fan