85 research outputs found
Automatic device for shell freezing of liquids
Unit is insulated enclosure designed to contain liquid nitrogen. It also includes set of stainless steel rotating rods for holding vessels containing liquids to be frozen, and electric drive mechanism for rotating these rods. Present device will accept 10 vessels at a time
Problem areas in the use of the firefly luciferase assay for bacterial detection
By purifying the firefly luciferase extract and adding all necessary chemicals but ATP in excess, an assay for ATP was performed by measuring the amount of light produced when a sample containing soluble ATP is added to the luciferase reaction mixture. Instrumentation, applications, and basic characteristics of the luciferase assay are presented. Effect of the growth medium and length of time grown in this medium on ATP per viable E. coli values is shown in graphic form, along with an ATP concentration curve showing relative light units versus ATP injected. Reagent functions and concentration methods are explored. Efforts to develop a fast automatable system to detect the presence of bacteria in biological fluids, especially urine, resulted in the optimization of procedures for use with different types of samples
Determination of antimicrobial susceptibilities on infected urines without isolation
A method is described for the quick determination of the susceptibilities of various unidentified bacteria contained in an aqueous physiological fluid sample, particularly urine, to one or more antibiotics. A bacterial adenosine triphosphate (ATP) assay is carried out after the elimination of non-bacterial ATP to determine whether an infection exists. If an infection does exist, a portion of the sample is further processed, including subjecting parts of the portion to one or more antibiotics. Growth of the bacteria in the parts are determined, again by an ATP assay, to determine whether the unidentified bacteria in the sample are susceptible to the antibiotic or antibiotics under test
Laboratory procedures manual for the firefly luciferase assay for adenosine triphosphate (ATP)
A manual on the procedures and instruments developed for the adenosine triphosphate (ATP) luciferase assay is presented. Data cover, laboratory maintenance, maintenance of bacterial cultures, bacteria measurement, reagents, luciferase procedures, and determination of microbal susceptibility to antibiotics
Application of firefly luciferase assay for adenosine triphosphate (ATP) to antimicrobial drug sensitivity testing
The development of a rapid method for determining microbial susceptibilities to antibiotics using the firefly luciferase assay for adenosine triphosphate (ATP) is documented. The reduction of bacterial ATP by an antimicrobial agent was determined to be a valid measure of drug effect in most cases. The effect of 12 antibiotics on 8 different bacterial species gave a 94 percent correlation with the standard Kirby-Buer-Agar disc diffusion method. A 93 percent correlation was obtained when the ATP assay method was applied directly to 50 urine specimens from patients with urinary tract infections. Urine samples were centrifuged first to that bacterial pellets could be suspended in broth. No primary isolation or subculturing was required. Mixed cultures in which one species was predominant gave accurate results for the most abundant organism. Since the method is based on an increase in bacterial ATP with time, the presence of leukocytes did not interfere with the interpretation of results. Both the incubation procedure and the ATP assays are compatible with automation
Use of mixed study techniques in the evaluation of coastline dynamics - the “Porto Cesareo” MPA case of study
In recent decades, the much-discussed climate changes with the consequent
variations in sea and weather conditions and the rise of the mean sea level are causing an
indisputable set of negative actions on the entire coastal system mainly due to the increase
of the erosive phenomenon along the shorelines. These critical scenarios have a major
impact even on a local scale, and because of that, we decided to study a well knows tract of
rocky/sandy mixed coast, in a highly anthropized area, even if located inside the “Porto
Cesareo” Marine Protected Area (MPA) (Ionian Sea, Gulf of Taranto, Puglia Region, Italy).
The high naturalistic and archaeological value of this area calls for a greater institutional
effort in the study of erosional phenomena. Several historical documents from other studies
point out that this coastal area is an ideal place for this kind of research. The effects of
coastal erosion and anthropic pressures along this tract of coast require adequate efforts for
a consistent and rapid evaluation of the coastal dynamics. The methodologies proposed in
this work are based on mixed techniques from different fields of study, integrating recent
aero photogrammetry surveys with drones, aerial images acquired by the Italian Military
Geographic Institute (IGM), elaboration of paleoshorelines related by underwater
archaeological markers and their dating, and finally on the elaboration of satellite products
useful for the study of vast areas. The monitoring of coastal areas and the evaluation of
shoreline dynamics are core topics in the implementation of managing actions of decision makers on a local, regional, national, and international scale, above all in places like the
chosen one, inside an MPA. Remote sensing through the use of RPAS (Remotely Piloted
Aircraft Systems or Drones) has proved to be very useful for identifying phenomena that
act on a small spatial scale and in supporting and implementing protective measures
according to the adaptive management approach, through multi-year surveys on habitats of
conservation interest [18]. For the implementation of fine-scale monitoring actions, we
have chosen products from the Sentinel satellite of the Copernicus constellation (European
Space Agency - ESA). In this context, the use of satellite products provides a recurrent
view of the ground, useful in the short and long-term monitoring of changes in wide coastal
areas, and in particular, offers a coastline positioning evaluation in near real-time. Local
monitoring actions performed in recent years have already shown an erosive trend in the
past decades, and even, negative forecasts for the next decade, so further surveys with
mixed methodologies could be crucial in the evaluation of the evolution of this particular
coastal area by local authorities
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Processing and properties of hot-forged bulk superconductors
(Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} (Bi-2223) and TlBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} (Tl-1223) bars were hot forged in air at 820--850C. Final stresses of 2--3 MPa were sufficient to produce >95% dense Bi-2223 bars. In contrast, stresses to {approx}42 MPa were able to produce only 75--80% dense Tl-1223 bars. The Bi-2223 bars were more phase-pure and exhibited much stronger c-axis textures than the Tl-1223. Maximum critical current densities at 77 K were 8 {times} 10{sup 4} A/cm{sup 2} for the Bi-2223 and 2 {times} 10{sup 4}/cm{sup 2} for the Tl-1223. Fracture strength and toughness values were 140 MPa and 2.9 MPa{radical}m for the Bi-2223 and 50 MPa and 0.5 MPa{radical}m for the Tl-1223
Hydrogen production by water dissociation using ceramic membranes - annual report for FY 2010.
The objective of this project is to develop dense ceramic membranes that can produce hydrogen via coal/coal gas-assisted water dissociation without using an external power supply or circuitry. This project grew from an effort to develop a dense ceramic membrane for separating hydrogen from gas mixtures such as those generated during coal gasification, methane partial oxidation, and water-gas shift reactions. That effort led to the development of various cermet (i.e., ceramic/metal composite) membranes that enable hydrogen production by two methods. In one method, a hydrogen transport membrane (HTM) selectively removes hydrogen from a gas mixture by transporting it through either a mixed protonic/electronic conductor or a hydrogen transport metal. In the other method, an oxygen transport membrane (OTM) generates hydrogen mixed with steam by removing oxygen that is generated through water splitting. This project focuses on the development of OTMs that efficiently produce hydrogen via the dissociation of water. Supercritical boilers offer very high-pressure steam that can be decomposed to provide pure hydrogen using OTMs. Oxygen resulting from the dissociation of steam can be used for coal gasification, enriched combustion, or synthesis gas production. Hydrogen and sequestration-ready CO{sub 2} can be produced from coal and steam by using the membrane being developed in this project. Although hydrogen can also be generated by high-temperature steam electrolysis, producing hydrogen by water splitting with a mixed-conducting membrane requires no electric power or electrical circuitry
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Hydrogen Separation Membranes - Annual Report for FY 2007.
The objective of this work is to develop dense ceramic membranes for separating hydrogen from other gaseous components in a nongalvanic mode, i.e., without using an external power supply or electrical circuitry
Hydrogen separation membranes annual report for FY 2010.
The objective of this work is to develop dense ceramic membranes for separating hydrogen from other gaseous components in a nongalvanic mode, i.e., without using an external power supply or electrical circuitry. The goal of this project is to develop dense hydrogen transport membranes (HTMs) that nongalvanically (i.e., without electrodes or external power supply) separate hydrogen from gas mixtures at commercially significant fluxes under industrially relevant operating conditions. These membranes will be used to separate hydrogen from gas mixtures such as the product streams from coal gasification, methane partial oxidation, and water-gas shift reactions. Potential ancillary uses of HTMs include dehydrogenation and olefin production, as well as hydrogen recovery in petroleum refineries and ammonia synthesis plants, the largest current users of deliberately produced hydrogen. This report describes the results from the development and testing of HTM materials during FY 2010
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