101,963 research outputs found
The Effects of Base Sheet Moisture Content on Size Penetration Characteristics
This thesis was designed to determine the effects of moisture on the penetration of size solution into a paper sample. The experiment involved use of laboratory equipment and procedures to accomplish the objectives of this experiment.
Handsheets were conditioned, sized, cut, stained, and viewed under a laboratory microscope to obtain the desired results. The results from this procedure determined that the area of size deposition was dependant upon the moisture content of the paper sheet. As the moisture content of the samples increased, the size was retained more on the sample\u27s surface as opposed to penetration into the paper web.
If the results obtained in this study can be reproduced on the machine scale, extensive capital benefits will be realized by the particular mill. The benefits will be in the form of increased production as well as a reduction in steam consumption. However, benefits obtained from this increase in moisture should be weighed against effects on strength as well as other problems associated with high moisture content utilization, such as moisture profile
A formula for Pl\"ucker coordinates associated with a planar network
For a planar directed graph G, Postnikov's boundary measurement map sends
positive weight functions on the edges of G onto the appropriate totally
nonnegative Grassmann cell. We establish an explicit formula for Postnikov's
map by expressing each Pluecker coordinate as a ratio of two combinatorially
defined polynomials in the edge weights, with positive integer coefficients. In
the non-planar setting, we show that a similar formula holds for special
choices of Pluecker coordinates.Comment: 15 pages, 6 figures. Extensive additions, including a generalization
for arbitrarily oriented planar graphs and a formula for some Pluecker
coordinates of non-planar perfectly oriented graph
Can PV or solar thermal systems be cost effective ways of reducing CO 2 emissions for residential buildings?
This paper compares two solar systems, an actual building integrated, photovoltaic roof (BIPV) and a notional solar thermal system for a residential block in London, UK. The carbon payback for the solar thermal system is 2 years, the BIPV system has a carbon payback of 6 years. Simple economic payback times for both systems are more than 50 years. Calculations considering the current UK energy price increase (10%/yr), reduce the economic payback time for the PV roof to under 30 years.The costs to reduce overall carbon dioxide emissions using a BIPV roof are £196/tonne CO2, solar thermal individual systems at £65/tonne CO2 and community solar thermal at £38/tonne CO2. The current spot market price for CO2 is £15/tonne CO2 (20). Capital costs for PV systems in particular must be significantly reduced for them to be a cost-effective way to reduce CO2. This paper compares two solar systems, an actual building integrated, photovoltaic roof (BIPV) and a notional solar thermal system for a residential block in London, UK. The carbon payback for the solar thermal system is 2 years, the BIPV system has a carbon payback of 6 years. Simple economic payback times for both systems are more than 50 years. Calculations considering the current UK energy price increase (10%/yr), reduce the economic payback time for the PV roof to under 30 years.The costs to reduce overall carbon dioxide emissions using a BIPV roof are £196/tonne CO2, solar thermal individual systems at £65/tonne CO2 and community solar thermal at £38/tonne CO2. The current spot market price for CO2 is £15/tonne CO2 (20). Capital costs for PV systems in particular must be significantly reduced for them to be a cost-effective way to reduce CO2
The Separate or Concurrent Effects of Methylphenidate and Alcohol on Acquisition and Retention of the Morris Water Maze in Adolescent Rats
Alcohol’s (A) capacity to impair learning and memory has been well documented in the Morris Water Maze (MWM) but few studies have examined methylphenidate’s (MPH) impact on MWM performance (Haidun et al., 2010; Zeise et al., 2007). Even fewer studies have evaluated concurrent administration of these two drugs in adolescent rats (see Markwiese, et al., 1998). This project used a rat model of adolescent drug use to examine individual effects of MPH and A, as well as polypharmacy interactions between MPH and A, on MWM spatial acquisition and retention.
Thirty-two adolescent (P30) male Long-Evans hooded rats were used. Subjects were assigned to one of 4 conditions based on drug administered prior to 6 consecutive acquisition sessions. Animals received 2 i.p. injections prior to each session. The methylphenidate group (MPH+S) received 2 mg/kg MPH and 1 ml/kg saline solution (S), the alcohol group (A+S) received 2 g/kg ethanol and S, the methylphenidate and alcohol group (MPH+A) received both MPH and A, and the saline control group (S+S) received S injections. MPH was administered 50 mins prior to each session and A administered 20 mins prior to each session. Each session consisted of 4 trials and rats swam from one of four start locations (N,E,S,W) to a submerged platform in the NE quadrant. Trial duration was 60 seconds and rats remained on the platform for 10 secs. Performances were video recorded, and latency and swim accuracy scored. Whishaw Corridors established a direct swim path from start location to platform and an error was recorded when swim paths exited the corridor. On day 7, the submerged platform was removed and a single, 60 sec retention test was conducted with no drug administered prior to test. Amount of time spent swimming in the NE quadrant was analyzed to assess retention.
Acquisition: Both dependent measures, latency and swim accuracy, yielded similar outcomes. Factorial ANOVAs and post hoc tests showed improvement across training sessions for all groups. Importantly, the MPH+A group was impaired relative to all other conditions, and the S+S group performed better than the A group. No significant differences were observed between S+S and MPH+S groups.
Retention: A one-way ANOVA of swim time in the NE quadrant revealed longer swim times for the S+S group compared to the A+S group, and longer swim times for the MPH+S group compared to the A+S group. No other significant differences were observed.
While all groups improved performance during acquisition, methylphenidate + alcohol compromised spatial learning, and alcohol alone impaired learning relative to controls. Interestingly, measures of retention indicated only alcohol diminished spatial memory in adolescent rats
When a quantum measurement can be implemented locally ... and when it cannot
Local operations on subsystems and classical communication between parties
(LOCC) constitute the most general protocols available on spatially separated
quantum systems. Every LOCC protocol implements a separable generalized
measurement -- a complete measurement for which every outcome corresponds to a
tensor product of operators on individual subsystems -- but it is known that
there exist separable measurements that cannot be implemented by LOCC. A
longstanding problem in quantum information theory is to understand the
difference between LOCC and the full set of separable measurements. In this
paper, we show how to construct an LOCC protocol to implement an arbitrary
separable measurement, except that with those measurements for which no LOCC
protocol exists, the method shows explicitly that this is the case.Comment: 21 pages, 7 figures. Extensively revised to include details of all
arguments, explicitly proving all results in full rigor. Version 3 has
sections reordered and other restructuring, but otherwise contains the same
discussion as version
Getting on the E List: E-Mail Use in a Community of Service Provider
This case examines how a community of organizations providing service to people experiencing homelessness made use of an electronic mail list. Current economic conditions have encouraged organizations in various sectors—including nonprofits—that might normally compete for scarce resources to collaborate with one another to increase their chances of survival. One set of tools likely to be of value in such relationships includes various online discussion technologies. An examination of this community’s email list use over a three-year period suggests a somewhat complex picture regarding technology use. More specifically, some issues both constrain and enable use. Additionally, seemingly basic and minimal uses of the list provided not only the greatest functionality for the users, but also led to several unanticipated consequences for those involved
Electrical self-aligning connector
A self-aligning electrical connector device includes a receptacle component having a conically contoured interior and a plug component having a correspondingly contoured conical body receivable in the receptacle component. The plug component has a number of spaced conductive ring elements with a mating face and the receptacle component includes corresponding spaced conductive ring elements providing mating interface with the mating face of the ring elements of the plug component when connected to it. Each ring element of the receptacle component has several segmented portions which defect downwardly when the plug component is inserted. A biasing force is asserted against the face of the ring elements of the plug component providing positive electrical contact and connection between the ring elements of the components
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