Seasonal Emergence Patterns of Black Flies (Diptera: Simuliidae) in Northwestern Pennsylvania

A two-year emergence trap study of black flies at four sites in northwestern Pennsylvania yielded 1%3 individuals of nine species. The collections included Prosimulium mixtum, P. jU5cum, Stegapterna mutata, Simulium aureum, S. excisum (recorded for the first time from Pennsylvania), S. gauldingi, S. sp. nr. innacens, S. vittatum, and S. tuberasum. Species richness for all sites peaked during May. Emergence collections below a sewage plant effluent outfall represented fewer individuals and species than collections above the effluent outfall. Chromosomal analysis of supplementary larval collections revealed the IIIL-l and IS-7 sibling species of S. vittatum and the FG sibling of S. tuberasum

A Stochastic Fractional Dynamics Model of Space-time Variability of Rain

Rainfall varies in space and time in a highly irregular manner and is described naturally in terms of a stochastic process. A characteristic feature of rainfall statistics is that they depend strongly on the space-time scales over which rain data are averaged. A spectral model of precipitation has been developed based on a stochastic differential equation of fractional order for the point rain rate, that allows a concise description of the second moment statistics of rain at any prescribed space-time averaging scale. The model is thus capable of providing a unified description of the statistics of both radar and rain gauge data. The underlying dynamical equation can be expressed in terms of space-time derivatives of fractional orders that are adjusted together with other model parameters to fit the data. The form of the resulting spectrum gives the model adequate flexibility to capture the subtle interplay between the spatial and temporal scales of variability of rain but strongly constrains the predicted statistical behavior as a function of the averaging length and times scales. We test the model with radar and gauge data collected contemporaneously at the NASA TRMM ground validation sites located near Melbourne, Florida and in Kwajalein Atoll, Marshall Islands in the tropical Pacific. We estimate the parameters by tuning them to the second moment statistics of radar data. The model predictions are then found to fit the second moment statistics of the gauge data reasonably well without any further adjustment

Plasma Electron Beam Welder for Space Vehicles Final Report

Feasibility of developing plasma electron beam welding system for earth orbiting vehicl

Beef Cattle Salmonellosis: A Study of Oral Salmonella typhimurium and Topical Salmonella newport Inoculations

Cattle are frequently infected with salmonellae by fecaloral transmission or by being fed contaminated animal protein byproducts (40% are reported contaminated in the U.S.). Bothcould propagate salmonellosis in feedlots. Research indicates that stress can induce shedding of salmonellae by asymptomatic carriers. Stress factors associated withsalmonellosis include: transportation, starvation, changes in ration, overcrowding, age, pregnancy, parturition, exertion, anesthesia, surgery, intercurrentdisease, and oral treatment withantibioticsand anthelmintics. In this study, we have attempted to correlate dosage of S. typhimurium inoculumwithdisease, persistence of infection, and environmental contamination. The persistence and spread of S. newport placed on the skin of cattle was also studied

Beef Cattle Salmonellosis: A Study of Oral Salmonella typhimurium and Topical Salmonella newport Inoculations

Cattle are frequently infected with salmonellae by fecaloral transmission or by being fed contaminated animal protein byproducts (40% are reported contaminated in the U.S.). Bothcould propagate salmonellosis in feedlots. Research indicates that stress can induce shedding of salmonellae by asymptomatic carriers. Stress factors associated withsalmonellosis include: transportation, starvation, changes in ration, overcrowding, age, pregnancy, parturition, exertion, anesthesia, surgery, intercurrentdisease, and oral treatment withantibioticsand anthelmintics. In this study, we have attempted to correlate dosage of S. typhimurium inoculumwithdisease, persistence of infection, and environmental contamination. The persistence and spread of S. newport placed on the skin of cattle was also studied

Spatial heterogeneity in projected leprosy trends in India

Background: Leprosy is caused by infection with Mycobacterium leprae and is characterized by peripheral nerve damage and skin lesions. The disease is classified into paucibacillary (PB) and multibacillary (MB) leprosy. The 2012 London Declaration formulated the following targets for leprosy control: (1) global interruption of transmission or elimination by 2020, and (2) reduction of grade-2 disabilities in newly detected cases to below 1 per million population at a global level by 2020. Leprosy is treatable, but diagnosis, access to treatment and treatment adherence (all necessary to curtail transmission) represent major challenges. Globally, new case detection rates for leprosy have remained fairly stable in the past decade, with India responsible for more than half of cases reported annually. Methods: We analyzed publicly available data from the Indian Ministry of Health and Family Welfare, and fit linear mixed-effects regression models to leprosy case detection trends reported at the district level. We assessed correlation of the new district-level case detection rate for leprosy with several state-level regressors: TB incidence, BCG coverage, fraction of cases exhibiting grade 2 disability at diagnosis, fraction of cases in children, and fraction multibacillary. Results: Our analyses suggest an endemic disease in very slow decline, with substantial spatial heterogeneity at both district and state levels. Enhanced active case finding was associated with a higher case detection rate. Conclusions: Trend analysis of reported new detection rates from India does not support a thesis of rapid progress in leprosy control

Interleaved Circuitry And Hybrid Control As Means To Reduce The Effects Of Flow Maldistribution.

Flow maldistribution in evaporators can lead to significant degradation of capacity and efficiency of vapor compression equipment. A significant amount of work has previously been done to mend these issues. For variable air flow maldistribution, refrigerant compensation was proposed to reduce the performance degradation. For fixed air side maldistribution, refrigerant circuitry modifications were proposed to significantly reduce the effects of the maldistribution. However, no work has been found on modifying the refrigerant circuitry to make it less vulnerable to varying air side maldistribution. The purpose of this paper is to fill this gap in open literature. The performance of the new, interleaved circuitry approach and an active refrigerant flow control is compared to the standard circuitry for different cases of maldistribution. The results show that the interleaved circuitry recovers less of the performance losses than equalization of the exit superheats. However, the implementation cost in an actual system is expected to be significantly lower and the long term reliability is expected to be much better than for an active control approach

Effects of Vapor Injected Compression, Hybrid Evaporator Flow Control, and Other Parameters on Seasonal Energy Efficiency.

A companion paper (Bach et al. 2014) experimentally investigated the effects of vapor injected compression and hybrid evaporator flow control on capacity and COP. The goal of this paper is to provide insight into the effects of these technologies on heating seasonal performance (HSPF). HSPF was calculated using a modified version of the ANSI/AHRI 210/240 method, and parametric studies were performed to better understand the seasonal performance with a focus on comparing vapor injected and single stage system configuration. It was found that part load degradation and reduced capacity at low ambient temperature are factors that can degrade the seasonal performance. The increase in heat pump COP for the vapor injected configuration leads to only a small benefit - the main contributor to the increased HSPF of the vapor injected system configuration is its increased capacity towards low ambient temperatures. References: Bach C. K., Vetsch, B., Groll, E. A., Braun, J. E., and Horton, W. T, (2014), Experimental Investigation of Vapor Injected Compression for Cold Climate Heat Pumps and its Effects on their Performance, 15th International Refrigeration and Air Conditioning Conference at Purdue, West Lafayette

Experimental Investigation of Vapor Injected Compression for Cold Climate Heat Pumps

Building heating requirements increase with decreasing ambient temperature, while the coefficient of performance of air-source heat pumps (ASHPs) shows the opposite trend. Additionally, heating capacity decreases with ambient temperature, which leads to the utilization of inefficient electric reheat below the design point. Increasing the capacity and COP at lower ambient temperatures is important for improving the market penetration of heat pumps in climates having significant operating time at low ambient temperature. Simulation studies previously showed that compressor vapor injection leads to an increase of COP under exactly those conditions. Furthermore, reduced capacity degradation towards smaller ambient temperatures was predicted. The work presented in this paper shows experimental results obtained from a commercially available 5-ton heat pump that was retrofitted with a two-port vapor injected scroll compressor. The injection ports within the two compression pathways are located in the fixed scroll with different distance from the suction chamber. The vapor for the two injection pressure levels was generated using two vapor separators in a cascade configuration. This configuration made it necessary to not only control the superheat but also the liquid levels in the separators and subcooling of the refrigerant leaving the condenser. Baseline performance data of the heat pump without vapor injection was obtained and compared with that for the vapor injection and other system configurations. For the baseline, the injection lines to the compression pockets were plugged within the fixed scroll to reduce dead volume and re-expansion losses. Also, the vapor-separator section was shut off and bypassed. In the second step, the plugs were removed and a staged expansion process was performed using the separator section. The generated vapor from each separator was injected into the respective compressor port causing an intercooling effect on the compression process. With identical compressor speed, a 28% improvement in capacity was achieved at the 8.33°C (47 F) design point, when compared to the baseline without vapor injection. When the baseline and vapor injected system capacity were matched by adjusting compressor speed, the COP increased by up to 6% at -8.33°C (17 F). Preliminary results of a bin-type analysis of the experimental data predicts an improvement in HSPF of 6% for Minneapolis and nearly 7% for AHRI climate region 5. The benefit is mainly caused by a reduction of the auxiliary electric heater’s runtime