Characterizing the mechanical behavior of single and polycrystalline silicon carbide using nanoindentation.

This research aims at enhancing the fundamental understanding of mechanisms controlling the deformation and fracture of silicon carbide based ceramics (single- and poly-crystal). The role of microstructure and material properties on the energy absorption capability of SiC is studied. This research helps to improve the ability to quantitatively predict the initiation and propagation of fracture and the interaction between fracture and plasticity, which provides a step towards a mechanistic understanding of deformation and failure properties of ceramic single crystals and polycrystals. The validity of the indentation-cracking method for toughness measurement is examined using nanoindentation tests with different indenters (spherical, pyramidal). Pyramidal indenters with various centerline to face angles are used to produce a wide range of effective strains in the single and polycrystalline SiC. Crystal plasticity constitutive laws can be calibrated using below threshold indentation loads. Above threshold loads are used to construct a parametric map that delineates the dependence of the ratio of crack size and contact radius on indenter geometry, applied load, toughness, and hardness, thus providing important guidelines for the toughness measurement method. By examining the behavior of several SiC materials during nanoindentation experiments using spherical and pyramidal indenters, it is possible to make predictions about methods to improve the ductility and fracture toughness of SiC to optimize its energy absorption. The applicability of the area under the irreversible part of the indentation load displacement curve (energy dissipated during loading) to predict the performance of SiC under contact loading is examined

Performance of Large Storage Tank in Bhuj Earthquake

The 2001 Bhuj earthquake of magnitude 7.7 caused a widespread damage in the state of Gujarat, India. This paper presents a case study of phosphoric acid storage tank weighing 100,000 kN and measuring 30 m in diameter built for a fertilizer plant in Kandla, Gujarat. The post earthquake performance assessment was carried out by exhuming the nearby piles and non-destructive testing of piles. The storage tanks supported on piles, installed in a ground treated with stone columns, showed no failure and have performed well during the earthquake. The design philosophy used to resist axial and lateral loads is explained

Lattice dynamics and specific heat of α‐helical poly(L‐alanine)

We have calculated the phonon dispersion relation in α‐poly(L‐alanine) with all atoms in the chemical repeat explicitly included and using a recently refined force field for the polypeptide chain. The phonon density of states shows very good agreement with the inelastic neutron scattering data for this polypeptide. The specific heat for T<150 K yields better agreement with experiment than did earlier calculations. At higher temperatures the discrepancy with experiment remains. We present a simple model calculation which suggests that the source of this discrepancy may lie in the anharmonicity of the methyl torsion mode.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69884/2/JCPSA6-84-12-6989-1.pd

Cure after re-resection of colorectal liver metastases in a 28 year old woman. A case report

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenLiver resection is the only well documented curative treatment for colorectal liver metastases but without surgery survival is dismal. Liver resections can be done for re-metastatic colorectal cancers if the tumors are localized in the liver. The first case of re-resection of colorectal liver metastases in Iceland is presented.Lífshorfur sjúklinga sem greinast með lifrarmeinvörp frá ristilkrabbameini eru slæmar og án meðferðar eru flestir dánir innan árs (1,2). Lifrarúrnám er eina læknandi meðferðin (3). Aðgerðinni má beita við endurtekin meinvörp (4,5). Lýst er tilfelli af endurteknu lifrarhöggi hér á landi

Slurry Phase Iron Catalysts for Indirect Coal LIquefaction.

This report covers the fourth six month period of this three year grant under the University Coal Research program. During this period, we have begun the synthesis of precipitated catalysts using a bench-top spray dryer. The influence of binders on particle strength was also studied using the ultrasonic fragmentation approach to derive particle breaking stress. A similar approach was used to derive particle strength of catalysts obtained from Mr. Robert Gormley at FETC. Over the next six month period, this work will be continued while the catalysts prepared here will be examined by TPR to determine reducibility and the extent of adverse iron-silica interactions. A fundamental study of Fe/silica interactions has been performed using temperature programmed reaction and TEM to provide understanding of how the silica binders influence the activity of Fe catalysts. To understand differences in the reducibility of the iron phase caused by silica, we have set up a temperature programmed reduction facility. TPR in H, as well as in CO was performed of Fe/ SiO, catalysts prepared by impregnation as well as by precipitation. What is unique about these studies is that high resolution TEM was performed on samples removed from the reactor at various stages of reduction. This helps provide direct evidence for the phase changes that are detected by TPR. We have continued the analysis of catalysts received from slurry reactor runs at Texas A&M university (TAMU) and the University of Kentucky Center for Applied Energy Research (CAER) by x-ray diffraction. The purpose of the XRD analysis was to determine the phase composition of catalysts derived from a slurry reaction run using Fe Fischer-Tropsch catalysts. We had previously described how catalyst removed in the hot wax may oxidize to magnetite if the wax is air-exposed. We have now received catalysts from CAER that were removed under a protective inert blanket, and we are in the process of analyzing them, but preliminary work presented here shows very little oxide by XRD. However, the catalyst that was used in these runs at CAER was a different composition than that used in previous runs, so the protective effect of an inert blanket will need further study. Finally, we point out how the interference by the wax can make it difficult in some cases to analyze the phases in a Fe catalyst. Several approaches have been used to remove the interference from the wax and we come to the surprising conclusion that Fe may be present in a working slurry reactor despite the high CO/ H{sub 2} ratio. Further work is underway to corroborate this finding

A case study of Plantar Psoriasis

Psoriasis is a long standing autoimmune disease characterized by patches of abnormal skin. It is non infectious chronic inflammatory disease of skin characterized by well defined erythmatous plaques with silvery scale. Psoraisis varies in severity from small localized patches to complete body coverage. It is a common skin disease affecting about 1-2 percent of the general population. The disease not only affects the patient physically but also disturbs the mental and social health of the patient. There is no satisfactory treatment available for Psoriasis. Ayurvedic treatment can give promosing results in such patients. Repeated Shodhan Chikitsa followed by various Shaman Yogas and Rasayan Chikitsa for continued remission are emphasized in treatment of Kushtha in all ancient Ayurvedic texts. In this article a case of plantar psoriasis is being presented which was treated successfully with Ayurvedic management

Low latency data retrieval solutions for big data

As applications are moving towards peta and exascale data sets, it has become increasingly important to develop more efficient data retrieval and storage mechanisms that will aid in reducing network traffic, server load, as well as minimizing user perceived retrieval delays. We propose an Intelligent Caching technique and a Graph Summarization technique in order to achieve low latency data retrieval for big data based applications. Our caching approach is developed on top of HDFS to optimize the read latency of HDFS. HDFS is primarily suitable for Write Once Read Many (WORM) applications where the number of reads is significantly more than that of writes. In our Intelligent Caching approach, we analyze real world map reduce traces from Facebook and Yahoo in terms of file size and access pattern distribution. We combine it with the existing analysis from literature to develop a new caching algorithm that builds on top of the HDFS caching API recently released. Based on the findings that a majority of accesses in a map reduce cluster occur within the first 2 hours of file creation, our caching algorithm uses a sliding window approach to ensure that most popular files remain in cache at appropriate time instances. It uses file characteristics for a particular window to determine a file's popularity. File popularity is calculated using file access patterns, file age and workload characteristics. We use a simulator based technique to evaluate our algorithm on various performance metrics by using real world and synthetic traces. We have compared our algorithm with some of the existing variants of LRU/LFU. Recent rapid growth in real-world social networks has incentivized researchers to explore optimizations which can provide quick insights about the network. Due to this motivation, graph summarization and approximation has been an important research problem. Most of the work in this area has been focused on concise and informative representations of large graph. These large graphs are billion nodes and edges graphs and need a distributed storage/processing system for any kind of operations on them. Our work primarily focuses on task-based summarization of large graphs that are stored in a distributed fashion and answer queries which are computationally expensive on original graph, but have tolerance with regards to minor errors in exact results. These queries, semantically, provide the same amount of information even with approximate results. Our contribution is a distributed framework which can answer queries probabilistically in a highly efficient way using compact representations of original graph stored in form of summary graphs across a cluster of multiple nodes. These summary graphs are also optimized for space complexity, and only grow in terms of the number of attributes used to answer the query. One can then use a combination of these graphs to answer complex queries in an extremely efficient manner. Our results are promising and show that significant gains in runtime can be achieved using our framework without sacrificing too much on accuracy. In fact, we observe decreasing trend in error as the graph size increases

Slurry Phase Iron Catalysts for Indirect Coal Liquefaction

This report describes research conducted to support the DOE program in indirect coal liquefaction. Specifically, we have studied the attrition behavior of Iron Fischer-Tropsch catalysts, their interaction with the silica binder and the evolution of iron phases in a synthesis gas conversion process. The results provide significant insight into factors that should be considered in the design of catalysts for the conversion of coal-derived synthesis gas into liquid fuels

SLURRY PHASE IRON CATALYSTS FOR INDIRECT COAL LIQUEFACTION Semi-Annual Technical Report

Abstract This report describes research conducted to support the DOE program in indirect coal liquefaction. Specifically, we have studied the attrition behavior of iron Fischer-Tropsch catalysts, their interaction with the silica binder and the evolution of iron phases in a synthesis gas conversion process. The results provide signficant insight into factors that should be considered in the design of catalysts for converting coal based syn-gas into liquid fuels. Executive Summary This report covers the third six months of this three year grant under the University Coal Research program. During this period, we have explored the uniaxial compaction method as an approach to derive particle breaking stress. The method was applied to alumina support granules obtained from Dr. Robert Gormley at PETC and will be extended to other F-T catalysts in future work. We also present ultrasonic fragmentation analysis of Fe/alumina F-T samples obtained from PETC. When the particle size evolution is compared with that of the base UCI catalyst, it is clear that the alumina-supported catalysts show significant improvement in particle strength. This work will be continued over the next six month period to better quantify the agglomerate strength of F-T catalysts, and to afford comparisons between the uniaxial compaction and ultrasonic fragmentation methods for determining the strength of F-T catalysts. During this period, we have continued our study of Fe/silica interactions to provide a fundamental understanding of the how silica binders influence the activity and attrition resistance of these catalysts. To understand differences in the reducibility of the iron phase caused by silica, we have set up a temperature programmed reduction facility. TPR in H 2 as well as in CO was performed of Fe/SiO 2 catalysts prepared by impregnation as well as by precipitation. We have completed analysis of catalysts received from slurry reactor runs at Texas A&amp;M university (TAMU) and the University of Kentucky Center for Applied Energy Research (CAER) by x-ray diffraction. The analysis results were conveyed to PETC, TAMU and CAER in September 96 are included here for the sake of completeness. The purpose of the XRD analysis was to determine the phase composition of catalysts derived from a slurry reaction run using Fe Fischer-Tropsch catalysts. As we describe in this report, the XRD results show that the carbide phase does not transform into magnetite over the course of a F-T run, both in the TAMU as well as in the CAER runs. The slow deactivation of these catalysts must then be related to crystallite growth and loss of active phase surface area. Further work is underway to corroborate this hypothesis. Technical Objectives The objective of this research project is to perform fundamental research in support of catalyst development for slurry phase bubble column reactors for Fischer-Tropsch synthesis. The overall program is divided into the following tasks: Task 1. Catalyst Particulate Synthesis Task 2. Catalyst Binder Interactions. In task 1, we will first study factors that determine the attrition resistance of slurry phase Fe catalysts. Fundamental understanding of the attrition phenomenon will be used to guide the synthesis of novel precipitated catalysts that overcome some of the limitations of current generation catalysts. The investigation of catalyst microstructure as a function of treatment will help determine the optimal treatment protocols for F-T synthesis catalysts. Since the use of binders is considered essential for providing the desired attrition resistance, the second 3 task is to perform fundamental studies of catalyst-binder interactions. These studies will use model catalysts that can be studied by high resolution transmission microscopy to investigate the nature of interfacial phases at the Fe-binder interface. A better understanding of the phenomena that lead to catalyst-binder interactions will help us design improved catalysts for indirect coal liquefaction. Task 3. Characterization of catalysts received from CAER, Univ. of Kentucky, and from Texas A&amp;M. Task 3 was not included in our original proposal. However, we are pursuing these studies to help understand catalyst deactivation under actual reaction conditions. Technical Progress Task 1: Catalyst Particulate Synthesis Overview In the previous six-monthly report we showed how ultrasonic excitation followed by sedigraph particle size distribution can yield a simple test for the strength of catalyst agglomerates. While the breakdown of particles subjected to ultrasound energy provides a graphic measure of particle strength, a number of assumptions must be made to derive a quantitative measure of particle strength. Hence, during the current six month period we have explored the use of a more conventional test for particle strength. Uniaxial Compression Testing Uniaxial compression testing is a technique for characterizing the strengths of powders and granular materials. Previously, the conventional method used for compression tests was the &quot;Brazilian test&quot;, in which individual particles were crushed between two platens (1). The drawback to this method was in the variability of strength due to variations of individual particle sizes and shapes. Furthermore, individual particle fracture loads are small (equivalent to a few grams&apos; weight) such that the accuracy of the data might not be high. A simple alternative method consisted of replacing the individual particle with a confined bed of similar particles, inferring some average individual particle strength parameter from the behavior of the whole bed under compression (1). This method is easily achieved using a piston in a cylinder, hence this method involves a uniaxial compaction (as shown on the next page). P h Confined Uniaxial Compression Test Uniaxial compression testing has been used by a group at Sandia National Laboratories in the study of ceramic granule strength. The tests were performed at the Advanced Materials Laboratory (a joint Sandia National Labs-University of New Mexico facility located on the university research park). For comparison, uniformly sized glass spheres were also used in their study. Diametral compression strength tests, similar to the &quot;Brazilian test&quot;, were performed (2) and the results were compared with those obtained with the uniaxial compaction test. The uniform-size glass spheres were used to eliminate the effects of shape and size factors, and minimize strength variability. Surprisingly, the results showed that the glass spheres also exhibited large variability in strength. The results for ceramic granules and uniform-size glass spheres were verified by using Weibull statistics; indeed, results the glass spheres gave similar Weibull parameters to those obtained from ceramic granules, indicating a large strength variability for individual glass spheres. Although the glass spheres were uniform in size, the large variability in strength was thought to arise from the large range in flaw sizes. To circumvent the tedious task of testing individual granules by the diametral compression test, pressure compaction (P-C) tests were also performed by Jill Glass and coworkers at SNL. Compaction behavior of these samples was determined by plotting the relative density of the compacted sample vs. the log of the compaction pressure as shown on the next page (2). 5 Relative Density Log(compaction pressure) Granule rearrangement Granule fracture + rearrangement Breakpoint This figure shows how the data of relative density vs log pressure can provide a semi-quantitative measure of agglomerate strength. As shown in this plot, compaction data tend to exhibit linear regimes that can be attributed to different compaction mechanisms (3). In the first regime, the gradual increase in relative density is due to particles, such as granules and agglomerates, sliding and rearranging without fracture. At this stage little compaction occurs, and only a small percentage of the void space is removed during rearrangement. It is often observed experimentally that this regime has a slope of ≈ 0.003-0.005. In the second regime, a sharp increase in relative density is due to deformation and fracture in conjunction with the sliding and rearrangement of particles (slope ≈ 0.2). At this stage a larger percentage of void space is removed during rearrangement. Best fit lines are often drawn through the points in the two linear regimes of the compaction plot. The intersection of these lines is called the breakpoint, which acts as a transition point for the two regimes. The breakpoint has been used as a semi-quantitative indicator of powder/granule strength or yield point, and is thought of as the average strength. Recent work at SNL, however, has demonstrated that it is more representative of the lower end of the range of powder or granule strengths. Beyond the second regime there may be another characteristic slope at higher pressures, but this has not been analyzed because it is still not well understood. In our work, we have explored the use of uniaxial compression testing to measure the strengths of Fischer-Tropsch catalysts. An Instron 5565 machine was used for compaction tests of these catalysts. This machine allows different-size dies to be used depending on the amount of samples available. We have chosen to work with an 1/8&quot; die to minimize the amount of sample required for a given test. Experimental Details A sample of VISTA-B-965-500C (Alumina), obtained from Dr. Robert Gormley at the Pittsburgh Energy Technology Center (PETC), was used for the uniaxial compression testing. Ten milligrams of this sample were loaded into the cell of a die with a 1/8&quot; opening. A plunger 6 was then placed on top of the filled die, taking great care not to compress the sample. To account for the error due to deformation of the top plunger and to the compliance of the crosshead, the displacement of the empty fixture as a function of load was subtracted from the displacement of the filled die. Compression tests were conducted by placing the filled die underneath the crosshead of the Instron machine. The crosshead was manually lowered such that it was just touching the top plunger. The displacement gauge was zeroed, and the crosshead was then activated at a rate of 1.00 mm/min. Testing was continued until a load of 1000 N was reached. The sample was repeated for reproducibility. For the first experiment, the sample was compacted at an aspect ratio, L f /D of 0.61 (where L f = final compact height and D = compact diameter); for the second experiment, the sample was compacted at an aspect ratio of 0.74. Results Figures 1 and 2 show plots of relative density vs. log of compaction pressure for the alumina. The relative density was calculated using the mass of alumina, initial compact height, measured displacement, and theoretical density. As expected, a low increase in relative density with an increase in pressure was followed by a region of sharp increase in relative density with pressure. The breakpoint was estimated by using best fit lines for the linear regimes and estimating the breakpoint via intersection of the lines. The breaking strength was determined to be 11.97 MPa from Ultrasonic fragmentation tests of F-T catalysts Figs. 3-5 provide fragmentation analysis of three of the catalysts also obtained from Dr. Robert Gormley at PETC. Future Work These results show that the uniaxial compaction and ultrasonic fragmentation tests may provide a good measure of the attrition resistance of F-T catalysts. Our future work will be devoted to developing consistent data analysis procedures for the compaction test and then comparing the ultrasonic fragmentation and compaction test results to the performance of catalysts in a slurry environment. We will expand the scope of these studies to include samples obtained from CAER and TAMU. During the course of this work, we will continue to study the microstructure of these catalysts to elucidate the role of binder morphology and loading on catalyst particle strength. Task 2 -Catalyst-binder interaction Overview The focus of the work performed during this period was temperature programmed reduction of supported and unsupported catalysts to study how the binder-catalyst interaction affects the reducibility of the iron phase. Experimental Two silica sphere supported iron catalysts, YJ/1-65A(20 wt % Fe, with 1 wt % Cu) and YJ/1-67(10 wt % Fe), were prepared by conventional incipient wetness impregnation and precipitation respectively. A UCI unsupported catalyst (1185-149, Fe 2 O 3 /CuO/K 2 O = 88.95/11/0.05) was used as a reference. In this study, a 10% CO/He or 10% H 2 /Ar reductant stream was used with 20-30 mg catalyst sample contained in a U-shaped quartz reactor. A Thermal Conductivity Detector (TCD) was used for the analysis. An in-line CO 2 trap or H 2 O trap located between the reactor and the detector was used to remove CO 2 or H 2 O formed during TPR process. The sample temperature was ramped in each experiment at 10 o C /min to 500 o C and then held at the latter temperature for 0.5-1 hour. Results Following an optimized TPR procedure, H 2 -TPR profiles were recorded for unsupported UCI-1185-149 catalyst where the effect of preconditioning, i.e. heating in flowing Ar at the specified temperature, was first explored (see CO-TPR Two sets of CO-TPR profile were also recorded for supported and unsupported catalysts ( Future Work We find that comparison of the 1st and 2nd run profiles of the unsupported catalyst shows 9 that the position of the peak corresponding to Fe 2 O 3 to Fe 3 O 4 is significantly changed for both H 2 as well as CO-TPR. This could be caused by severe sintering of the catalyst during the 1st-run TPR as well as phase segregation of copper from iron. While the promotion effect of copper on the reduction of iron catalysts has been seen in previous work, the effect of the copper on the formation of carbide phases is not well understood. In future work, we will examine the microstructure of catalysts removed at various stages of the TPR runs to help answer some of these questions, particularly the role of Cu and the nature of interaction of the iron oxide phase with the silica support. Task-3: Characterization of catalysts from Univ. of Kentucky &amp; Texas A&amp;M Overview The analysis of samples obtained from CAER and TAMU over the course of a continuous F-T run are presented below. XRD analysis of samples in wax from run SB-3425 performed at TAMU An XRD pattern of natural magnetite is enclosed for reference TOS=000 hrs TOS=111hrs TOS=233hrs TOS=330 hrs TOS=384hrs Summary Over the 400 hours of running in an FT synthesis reactor, there is no apparent transformation of the carbide into magnetite even though the CO conversion is 80%. The slight deactivation seen at 330 hours may be attributed to the increased peak height of the carbide peaks (in-10 creased crystallinity, loss of surface area) and could also be possibly related to the disappearance of the peak at 2.226 Å and 2.984 Å This may suggest transformation of one form of carbide into another. XRD analysis of samples in wax from run RJO-189 performed at CAER We have analyzed the catalyst samples from this run that are embedded in wax. Since, there is an overlap between carbide and magnetite peaks at around 2.1 Å, we have used Reitveld analysis to strip the magnetite peaks from the spectrum. In this way, the carbide peaks can be clearly identified and the phase transformations from carbide to magnetite better understood. RJO-189F TOS=20h RJO-189G TOS=122h RJO-189G TOS=122h RJO 189J TOS=888 h RJO 189M TOS=1796 h RJO 189M TOS=1796 h RJO 189M TOS=1796 h RJO 189P TOS=3547 h RJO 189P TOS=3547 h 11 Summary The full width at half maximum of the magnetite peak does not change significantly over the course of this run. This implies that there is no appreciable coarsening or grain growth of the magnetite phase. Examination of the peak areas of various magnetite peaks shows that the relative size of the peak at 2.099 is greater than that in the natural magnetite sample. This is due to overlap between the carbide and magnetite. As a first guess, these results would indicate that there is no significant transformation of carbide into magnetite over the course of the 3000 hour run. Had there been a transformation, the magnetite peak ratios should have approached those of natural magnetite as carbide was progressively converted into magnetite. There are important differences between the XRD patterns of these samples and those from the run performed at Texas A&amp;M despite similarities in the operating conditions and pretreatment: 1. There are significant amounts of magnetite in the CAER samples while the amount of magnetite in the Texas A&amp;M samples is negligible. The wax removal at Texas A&amp;M is performed under an inert blanket while an inert blanket is not used during removal of the hot wax at CAER for this particular run. The role of the wax removal procedure on the relative amounts of magnetite and carbide need to be explored. The carbide peaks are well defined and show more lines than those in the CAER samples. Is this a result of these being different carbides or is it caused by difference in the extent of oxidation. We also do not have a sample of the catalyst after reduction and therefore do not know the extent of transformation to α-Fe during the reduction step. It would help to obtain a sample of this catalyst after the 220 °C H 2 activation so we could determine the phases present at the start of the run. If this reduction is performed for generating this sample, it would be useful to obtain sample with and without an inert blanket during discharge of the hot wax so that we can get an assessment of the extent of catalyst oxidation during wax discharge. 2. The loss of activity seems to be related to the increased crystallinity of the sample with time on stream. The peak intensity appears to increase with the XRD peaks becoming more well defined. This could be a result of the crystallite growth which would lead to loss of surface area. The peak widths of the magnetite peak do show a slight decrease in peak broadening with time on stream. However, at these particle sizes, particularly with the possible effects of lattice strain in the carbide, it may be best to resort to TEM analysis to infer the particle size changes. Future Work In future work, we will examine the wax stripped samples from these runs to derive detailed morphological information by electron microscopy. We would like to obtain from CAER a sample in wax after H 2 treatment under the conditions used in this run with and without an inert blanket. This will allow us to assess the extent of catalyst oxidation during wax removal and also establish the initial phase composition of this catalyst. 1

Laparoscopic cholecystectomy. The first 400 cases at Akureyri Central Hospital

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenObjective: To assess the outcome of the first 400 laparoscopic cholecystectomies (LC) in Akureyri Central Hospital (FSA), Iceland. Methods: We carried out a prospective study of LCs performed between July 1992 and February 2001. Primary endpoints were complication- and conversion rate, hospital stay and duration of convalescence. Results: A total of 426 operations were performed in the period. In 26 cases it was decided beforehand to perform an open cholecystectomy (OC). A LC was begun on 400 patients. Indication for operation was acute cholecystitis in 41 cases (10,3%) and an elective LC was performed in 359 (89,7%) cases. Conversion to OC was required in sixteen (4%) cases with a conversion rate in acutely performed LCs of 12,2% versus 3,1% in elective LCs. Mean hospital stay after LC was 3,6 days (1-45) versus 12,3 days (4-31) after OC. Mean operation time was 89 minutes (45-270) in the first 100 LCs versus 75 minutes (30-180) in the last 100 LCs. Duration of convalescence of patients undergoing LC was 13,5 days (4-70). Complication rate in LCs was 10% (40/400). Four patients required a reoperation. Conclusions: Our results show that LC is a safe procedure in FSA. Conversion rate to OC, complication rate and duration of convalescence stands good comparison to other studies.Tilgangur: Að meta árangur við fyrstu 400 gallblöðrunám með kviðsjártækni á Fjórðungssjúkrahúsinu á Akureyri (FSA). Efniviður og aðferðir: Gerð var framsæ rannsókn á tímabilinu júlí 1992 til febrúar 2001. Tíðni fylgikvilla og breytingar yfir í opna aðgerð var athuguð, auk þess sem lengd sjúkrahúsdvalar og tími til fyrri færni voru borin saman við niðurstöður annarra sjúkrahúsa. Niðurstöður: Alls voru framkvæmd 426 gallblöðrunám á sjúkrahúsinu. Í 26 tilfellum var um hefðbundna opna aðgerð að ræða frá byrjun. Gallblöðrunám með kviðsjártækni var reynt hjá 400 sjúklingum. Hjá 41 sjúklingi (10,3%) var um að ræða aðgerð vegna bráðrar gallblöðrubólgu og 359 sjúklingar voru teknir í valaðgerð. Snúa þurfti 16 (4%) kviðsjáraðgerðum í opna aðgerð, hlutfall opnunar við bráðaaðgerðir var 12,2% á móti 3,1% við valaðgerðir. Meðalfjöldi legudaga var 3,6 dagar (1-45) eftir kviðsjáraðgerðir á móti 12,3 dögum (4-31) eftir opnar aðgerðir. Meðal aðgerðartími við fyrstu 100 kviðsjáraðgerðirnar var 89 mínútur (45-270) og 75 mínútur (30-180) við síðustu 100 aðgerðirnar. Meðalfjöldi veikindadaga eftir kviðsjáraðgerðir var 13,5 dagar (4-70). Eftir gallblöðrunám með kviðsjártækni var tíðni fylgikvilla 10% (40/400). Enduraðgerð þurfti að framkvæma hjá fjórum sjúklingum. Ályktun: Gallblöðrunám með kviðsjártækni er örugg aðgerð á FSA. Hlutfall kviðsjáraðgerða, sem breyta þurfti í opna aðgerð, tíðni fylgikvilla og færni sjúklinga stenst fyllilega samanburð við aðrar rannsóknir