Basic study on the oil recovery in a hybrid heat pump using ammonia/water solution

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.In an ammonia/water hybrid heat pump system which is a vapor compression cycle with a solution circuit, lubricating oil is commonly used for the compressor. Since Poly-Alpha-Olefin (PAO) oil which is commonly used for ammonia is immiscible with the ammonia/water solution, a proper oil recovery method is required for a smooth operation of the compressor. Although the oil separator installed at the outlet of the compressor removes most of the oil from the refrigerant vapor, some oil droplets are carried over and accumulated in the solution reservoir. Unlike the pure ammonia vapor compression system, the density of PAO oil is smaller than that of ammonia/water mixture which has the ammonia concentration of 30-40%, and the oil tends to rise and gather near the liquid/vapor interface. In this study, a method for oil recovery from the solution reservoir is suggested. In the present method, the mixture of the oil and the solution is drained into an oil separator having a narrow cylinder at the top, if the oil in the reservoir is greater than a certain amount. The oil droplets in the solution rise by buoyancy and gather at this upper narrow cylinder. The gathered oil is extracted and returned to the compressor by an oil recovery pump. Since the solution has to be returned to the reservoir as soon as the separation process is finished, the process time for the separation should be as short as possible. To predict the time for the separation, experiments and simulations have been carried out. The model using the multiphase segregated flow (MSF) showed that a proper choice of droplet diameter is necessary to predict a correct separation time. Also, a simulation model which is able to consider the effect of surface tension and droplet merging is needed to be developed.dc201

GarlicESTdb: an online database and mining tool for garlic EST sequences

<p>Abstract</p> <p>Background</p> <p><it>Allium sativum</it>., commonly known as garlic, is a species in the onion genus (<it>Allium</it>), which is a large and diverse one containing over 1,250 species. Its close relatives include chives, onion, leek and shallot. Garlic has been used throughout recorded history for culinary, medicinal use and health benefits. Currently, the interest in garlic is highly increasing due to nutritional and pharmaceutical value including high blood pressure and cholesterol, atherosclerosis and cancer. For all that, there are no comprehensive databases available for Expressed Sequence Tags(EST) of garlic for gene discovery and future efforts of genome annotation. That is why we developed a new garlic database and applications to enable comprehensive analysis of garlic gene expression.</p> <p>Description</p> <p>GarlicESTdb is an integrated database and mining tool for large-scale garlic (<it>Allium sativum</it>) EST sequencing. A total of 21,595 ESTs collected from an in-house cDNA library were used to construct the database. The analysis pipeline is an automated system written in JAVA and consists of the following components: automatic preprocessing of EST reads, assembly of raw sequences, annotation of the assembled sequences, storage of the analyzed information into MySQL databases, and graphic display of all processed data. A web application was implemented with the latest J2EE (Java 2 Platform Enterprise Edition) software technology (JSP/EJB/JavaServlet) for browsing and querying the database, for creation of dynamic web pages on the client side, and for mapping annotated enzymes to KEGG pathways, the AJAX framework was also used partially. The online resources, such as putative annotation, single nucleotide polymorphisms (SNP) and tandem repeat data sets, can be searched by text, explored on the website, searched using BLAST, and downloaded. To archive more significant BLAST results, a curation system was introduced with which biologists can easily edit best-hit annotation information for others to view. The GarlicESTdb web application is freely available at <url>http://garlicdb.kribb.re.kr</url>.</p> <p>Conclusion</p> <p>GarlicESTdb is the first incorporated online information database of EST sequences isolated from garlic that can be freely accessed and downloaded. It has many useful features for interactive mining of EST contigs and datasets from each library, including curation of annotated information, expression profiling, information retrieval, and summary of statistics of functional annotation. Consequently, the development of GarlicESTdb will provide a crucial contribution to biologists for data-mining and more efficient experimental studies.</p

Strong ferromagnetism in Pt-coated ZnCoO: The role of interstitial hydrogen

We observed strong ferromagnetism in ZnCoO as a result of high concentration hydrogen absorption. Coating ZnCoO with Pt layer, and ensuing hydrogen treatment with a high isostatic pressure resulted in a highly increased carrier concentration of 10(21)/cm(3). This hydrogen treatment induced a strong ferromagnetism at low temperature that turned to superparamagnetism at about 140 K. We performed density functional method computations and found that the interstitial H dopants promote the ferromagnetic ordering between scattered Co dopants. On the other hand, interstitial hydrogen can decrease the magnetic exchange energy of Co-H-Co complexes, leading to a reduction in the blocking temperature.open7

Extreme Duplication-type, Nonseparated Fenestration of the Basilar Artery in a Patient with Pontine Infarction: Confirmation with Virtual Arterial Endoscopy

We present a case of a 55-year-old woman with pontine infarction and fenestration of the basilar artery that was demonstrated using virtual endoscopy. The patient had motor weakness of the right side with sudden onset. Diffusion- and T2-weighted MR images revealed high signal intensities in the left pontine regions, and an MR angiographic examination showed the double-lumen sign of the basilar artery. An extensive duplication-type, nonseparated fenestration of the basilar artery was diagnosed by virtual endoscopy and craniocaudal communications with discrete openings were observed. We report a case of a patient with basilar artery fenestration and associated brainstem infarction

Positional Reproducibility and Effects of a Rectal Balloon in Prostate Cancer Radiotherapy

Despite the increasing use of the rectal balloon in prostate cancer radiotherapy, many issues still remain to be verified objectively including its positional reproducibility and relevance to treatment morbidity. We have developed a custom rectal balloon that has a scale indicating the depth of insertion and dilates symmetrically ensuring positional reproducibility. Fifty patients with prostate cancer treated by definitive 3D-conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) with rectal balloon were analyzed. Each of first five patients undergone computed tomography (CT) three times with a rectal balloon. The positional reproducibility was tested by Intraclass Correlation Coefficient (ICC) from the CT-to-CT fusion images. Planning variables and clinical acute toxicities were compared between when or not applying balloon. An ICC of greater than 0.9 in all directions revealed an excellent reproducibility of the balloon. Rectal balloon improved considerably the mean dose and V45Gy-V65Gy in plan comparison, and especially in 3D-CRT the rectal volume exposed to more than 60 Gy dropped from 41.3% to 19.5%. Clinically, the balloon lowered acute toxicity, which was lowest when both the balloon and IMRT were applied simultaneously. The rectal balloon carries excellent reproducibility and reduces acute toxicity in 3D-CRT and IMRT for prostate cancer

Incidence and mortality of hip fracture among the elderly population in South Korea: a population-based study using the National Health Insurance claims data

<p>Abstract</p> <p>Background</p> <p>The lack of epidemiologic information on osteoporotic hip fractures hampers the development of preventive or curative measures against osteoporosis in South Korea. We conducted a population-based study to estimate the annual incidence of hip fractures. Also, we examined factors associated with post-fracture mortality among Korean elderly to evaluate the impact of osteoporosis on our society and to identify high-risk populations.</p> <p>Methods</p> <p>The Korean National Health Insurance (NHI) claims database was used to identify the incidence of hip fractures, defined as patients having a claim record with a diagnosis of hip fracture and a hip fracture-related operation during 2003. The 6-month period prior to 2003 was set as a 'window period,' such that patients were defined as incident cases only if their first record of fracture was observed after the window period. Cox's proportional hazards model was used to investigate the relationship between survival time and baseline patient and provider characteristics available from the NHI data.</p> <p>Results</p> <p>The age-standardized annual incidence rate of hip fractures requiring operation over 50 years of age was 146.38 per 100,000 women and 61.72 per 100,000 men, yielding a female to male ratio of 2.37. The 1-year mortality was 16.55%, which is 2.85 times higher than the mortality rate for the general population (5.8%) in this age group. The risk of post-fracture mortality at one year is significantly higher for males and for persons having lower socioeconomic status, living in places other than the capital city, not taking anti-osteoporosis pharmacologic therapy following fracture, or receiving fracture-associated operations from more advanced hospitals such as general or tertiary hospitals.</p> <p>Conclusion</p> <p>This national epidemiological study will help raise awareness of osteoporotic hip fractures among the elderly population and hopefully motivate public health policy makers to develop effective national prevention strategies against osteoporosis to prevent hip fractures.</p