Split Types Research Articles

Imaging Classification by Column and Type of the Generalized Distal Radius Die-punch Fractures

Background:: Generalized distal radius die-punch fractures (GDP) can involve three columns. However, there is no three-column classification for GDP. The aim of this study was to introduce a three-column classification for GDP, and to investigate the application effect of the classification. Methods:: 613 patients with GDP accrued from January 2013 to December 2021 were classified by column and fracture type based on imaging findings. First, the GDP was categorized into single-, double-, or three-column fractures. Second, the intermediate column fractures were divided into volar, dorsal, split, collapse, or mixed types; the radial column fractures were divided into metaphyseal, articular or mixed types; and the ulnar column fractures were divided into apical or basal types of the styloid process. The intra- and inter-observer consistency between the two assessors was analyzed with kappa statistics. 227 patients with less fracture displacement were treated conservatively, whereas 386 patients with increased fracture displacement were treated surgically, and the selection of surgical approaches and fracture reduction-fixation methods was guided by the classification. The differences in incidence, gender, age, treatment methods, and functional recovery were compared among the three categories, and the characteristics of different types were observed. The wrist joint function was evaluated according to the Sarmiento-modified Gartland- Werley method. Results:: The intra- and the inter-observer kappa coefficients were obtained as ≥ 0.810. There were significant differences in the incidence (12.7%, 68.5%, and 18.8%, respectively) and age (39.8, 46.6, and 47.1 years, respectively) for single-, double- and three-column fractures (P<0.05). However, there was no significant difference in terms of gender among the three (P>0.05). The mixed, collapse, split, dorsal, and volar types accounted for 28.7%, 27.7%, 21.9%, 15.5%, and 4.5%, respectively. The metaphyseal, articular surface, and mixed types accounted for 35.9%, 33.1%, and 31.0%, respectively. The apical and base types were 81.7% and 18.3%, respectively. Among the cases of volar and dorsal types, the missed diagnosis rate of X-ray alone was 28.5%, but it was confirmed by subsequent CT. In the last follow-up of 12.2 months (range, 6 to 24 months), the excellent plus good rate was 82.7% and 82.6%, respectively, in total and among patients undergoing surgical treatment; the excellent plus good rate of the single column fractures was 96.2%, significantly higher than that of double- and three-column fractures (80.0% and 83.5%, respectively) (P<0.05). All patients with fair or poor wrist function had collapse or mixed-type intermediate column fractures. Conclusion:: Different categories/types of GDP have significant differences in terms of incidence, age, efficacy, and prognosis. Imaging classification by column and type of GDP better reflects the features and injury mechanism of the fractures with good consistency. Therefore, it has important reference value for the surgical modality and prognosis evaluation.

Typology and Modeling Profiles of Moving-Class Process-Entity Interactions: Core Types, Relationships, Constraints and Subschemas

Most of scientific research that are immediately concerned with the development of domain digital models, to one degree or another, is aimed at the derivation of reference conceptual and logical constructions covering all pertinent classes of interactions in which real-world objects with concomitant constraints can be involved. This work is directed to forming the core of a structural template that models facts — instances of associates that arise during the movement (transportation) of freights. The multiple alternatives and high variability of any processes logic, including moving-class processes, make their complete unification problematic. Nevertheless, one can come down to process modeling from a system-wide perspective, focusing on the capture of universal permanent processes components, such as source and output sets of objects, associations and constraints. The reality exhibits examples of hierarchical coherence of any classes of generalized processes, which in their sequential development break up into several self-sufficient processes distributed between organizational, calendar and implementation phases. The main focus of the work is on the sequential (from simple to complex) configuration of the structural core of process-entity interactions in the organizational phase, covering route segments, transport and freights, as well as the study of constraints on permissible instances of links incoming into the corresponding associative complex. Conceptual diagrams are presented in simplified and thorough formats. In a simplified format, multi-valued dependencies are modeled by means of weak entities and relators. In a thorough format, weak entities and relators have been replaced with documentary types, the structures of which contain an eXhaustive set of information about all objects, including auXiliary ones that are involved in interactions. The paper also considers the influence of the environment that is represented by classifying sets on the content of bounded relationships operating between the entity and process types. We have ascertained, formalized and described all constraints appearing in the organizational phase of generalized transport process including new constraint kind — split dependent link, resulting from the formation of cycles in conceptual constructions. Similar cycles contain and link together split, entity and (or) process types.

The Effectiveness of the Water Additional Ingredient Urea CO(NH2)2 to the Concrete Fc' 20 MPA on Curing Process

Concrete quality depends on the value of the ratio of materials, how to blend and how to pour the concrete mixture, how to compact and how to care for it during the hardening process. This study aims to determine how much influence the curing process using water with a mixture of Co(NH2)2 and normal water has on the compressive strength of concrete fc' 20 Mpa. The sample is a cylindrical specimen with a diameter of 15 cm and a height of 30 cm. Samples were made 3 test objects with the age of 28 days and tested coherently. The compressive strength of normal concrete has increased in quality with the age between 7 is 9.1 Mpa to 28 days is 17 Mpa. While the concrete with curring process using water with a mixture of urea increased at age 7 with a value of 10.8 Mpa to 21 days with a value of 14.4 Mpa, but at age 28 the strength of the concrete decreased by 12 Mpa. Cracks with cone and split types are 10 pieces, this can happen because the material in the concrete mixer has not been mixed well during the concrete manufacturing process.

3D geological implicit modeling method of regular voxel splitting based on layered interpolation data

In view of the problems in traditional geological modeling methods, such as the insufficient utilization of geological survey data, the inaccurate expression of a stratigraphic model, and the large amount of model data, a 3D geological model cannot be smoothly loaded and rendered on the web end. In this paper, a 3D geological implicit modeling method of regular voxel splitting based on hierarchical interpolation data is proposed. This method first uses the boreholes and geological section data from a geological survey for data conversion and fusion, compares the applicability of different interpolation algorithms through cross-validation research, and uses the best fitting algorithm to interpolate and encrypt discrete points in the formation. Then, it constructs the regular voxels, designs five different regular voxel split types, and divides the voxels. In addition, the data structure design of the voxel split model is implemented, and the irregular voxel metadata structure is analyzed and displayed through Three.js. Using this method, based on the survey data of an area in Zhengzhou, the global workflow from data processing to model construction and visualization is demonstrated. The experimental results show that the model can integrate multisource hierarchical interpolation data; express different stratum structures accurately and smoothly, and can realize the rendering, spatial query and analysis of the internal information of a geological body in a browser.

Configurable Fast Block Partitioning for VVC Intra Coding Using Light Gradient Boosting Machine

This article presents a configurable fast block partitioning decision for Versatile Video Coding (VVC) intra-frame prediction using Light Gradient Boosting Machine (LGBM). VVC further improves the coding efficiency by introducing a Quadtree with nested Multi-Type Tree (QTMT), enabling five split types allowing square and rectangular Coding Unit (CU) sizes. However, this improvement in the coding efficiency comes at the cost of a high computational burden since several combinations of block sizes and prediction modes are evaluated through the costly Rate-Distortion Optimization (RDO) process. In this article, we propose a partitioning decision using LGBM classifiers to avoid the exhaustive RDO process and skip the evaluation of split types that are unlikely to be chosen as the best one. For this purpose, five classifiers (one for each split type) were offline trained with an efficient training process and using effective features of texture, coding, and context information. The proposed solution is highly configurable and can provide several operation points with different tradeoffs between timesaving and coding efficiency, according to the application requirements. Considering five operation points, the configurable solution can reduce the encoding time from 35.22% to 61.34%, with coding efficiency losses from 0.46% to 2.43%. Compared to the state-of-the-art, our solution is able to outperform the related works in terms of combined rate-distortion and timesaving.

Interaction forests: Identifying and exploiting interpretable quantitative and qualitative interaction effects

Although interaction effects can be exploited to improve predictions and allow for valuable insights into covariate interplay, they are given limited attention in analysis. Interaction forests are a variant of random forests for categorical, continuous, and survival outcomes that explicitly models quantitative and qualitative interaction effects in bivariable splits performed by the trees constituting the forests. The new effect importance measure (EIM) associated with interaction forests allows for ranking of covariate pairs with respect to their interaction effects' importance to prediction. Using EIM, separate importance value lists for univariable effects, quantitative interaction effects, and qualitative interaction effects are obtained. In the spirit of interpretable machine learning, the bivariable split types of interaction forests target easily interpretable and communicable interaction effects. To learn about the nature of the interplay between covariates identified as interacting it is convenient to visualise their estimated bivariable influence. Functions that perform this task are provided in the R package diversityForest, which implements interaction forests. In a large-scale empirical study using 220 data sets, interaction forests tended to deliver better predictions than conventional random forests and competing random forest variants that use multivariable splitting. In a simulation study, EIM delivered considerably better rankings for the relevant quantitative and qualitative interaction effects than competing approaches. These results indicate that interaction forests are suitable tools for the challenging task of identifying and making use of easily interpretable and communicable interaction effects in predictive modelling.

Unsupervised Binary Protocol Clustering Based on Maximum Sequential Patterns

With the rapid development of the Internet, a large number of private protocols emerge on the network. However, some of them are constructed by attackers to avoid being analyzed, posing a threat to computer network security. The blockchain uses the P2P protocol to implement various functions across the network. Furthermore, the P2P protocol format of blockchain may differ from the standard format specification, which leads to sniffing tools such as Wireshark and Fiddler not being able to recognize them. Therefore, the ability to distinguish different types of unknown network protocols is vital for network security. In this paper, we propose an unsupervised clustering algorithm based on maximum frequent sequences for binary protocols, which can distinguish various unknown protocols to provide support for analyzing unknown protocol formats. We mine the maximum frequent sequences of protocol message sets in bytes. And we calculate the fuzzy membership of the protocol message to each maximum frequent sequence, which is based on fuzzy set theory. Then we construct the fuzzy membership vector for each protocol message. Finally, we adopt K-means++ to split different types of protocol messages into several clusters and evaluate the performance by calculating homogeneity, integrity, and Fowlkes and Mallows Index (FMI). Besides, the clustering algorithms based on Needleman–Wunsch and the fixed-length prefix are compared with the algorithm presented in this paper. Compared with these traditional clustering methods, we demonstrate a certain improvement in the clustering performance of our work.

Verification of Subseasonal-to-Seasonal Forecasts for Major Stratospheric Sudden Warmings in Northern Winter from 1998/99 to 2012/13

This study reports verification results of hindcast data of four systems in the subseasonal-to-seasonal (S2S) prediction project for major stratospheric sudden warmings (MSSWs) in northern winter from 1998/99 to 2012/13. This report deals with average features across all MSSWs, and possible differences between two MSSW types (vortex displacement and split types). Results for the average features show that stratospheric forecast verifications, when further averaged among the four systems, are judged to be successful for lead times around 10 d or shorter. All systems are skillful for lead times around 5 d, whereas the results vary among the systems for longer lead times. A comparison between the MSSW types overall suggests larger forecast errors or lower skill for MSSWs of the vortex split type, although the differences do not have strong statistical significance for almost all cases. This limitation is likely to at least partly reflect the small sample size of the MSSWs available.

The incidence of occult and missed surgical neck fractures in patients with isolated greater tuberosity fracture of the proximal humerus

BackgroundOccult and missed surgical neck fractures can be found in patients diagnosed with isolated greater tuberosity (GT) fracture during the follow up period. The purpose of this study was to retrospectively assess the incidence rate of occult and missed surgical neck fractures in those initially diagnosed with isolated GT fracture.MethodsRecords of patients diagnosed as having an isolated GT fracture were retrieved from a database in a medical center. Two senior orthopedic surgeons blindly reviewed all images of these patients three times to classify GT fracture types (split, avulsion and depression types), and recorded any surgical neck fractures found. Then a meeting was help to confirm the fracture types and presence of surgical neck fracture.ResultsOccult surgical neck fractures were found in 5 out of 68 (7.4%) patients, whereas missed surgical neck fractures were found in 3 out of 68 (4.4%) patients. In total, 32 patients had split type GT fracture, 32 had avulsion type and 4 had depression type. For those with occult surgical neck fractures, 7 had the split type GT fracture, while the remaining one had the avulsion type. Although the proportion of occult surgical neck fracture was higher in the split-type GT fracture (21.9%) than in the avulsion-type GT fracture (3.1%), the difference was not statistically significant (p = 0.056).ConclusionOccult humeral surgical neck fractures occurred in 7.4% of isolated greater tuberosity fractures after re-evaluation, while missed humeral surgical neck fractures occurred in 4.4%.

CT variants of the caudal vena cava in 121 small breed dogs.

Computed tomography is increasingly used as a treatment planning method in canine patients with diseases of the retroperitoneum, however, published information on normal variations in the caudal vena cava (CVC) are currently lacking. The objectives of this retrospective descriptive study were to characterize CVC variants using CT angiography in a sample of small breed dogs and localize the CVC bifurcations for each variant. Inclusion criteria were small breed dogs (weight≤15) that underwent contrast-enhanced CT scans of the CVC, abdominal aorta, and CVC tributaries. A total of 121 small breed dogs were sampled. Four right-sided and one left-sided CVC variations were identified: normal (88/121, 72.7%), caudal-partial split (17/121, 14.0%), partial duplication (8/121, 6.6%), complete duplication (7/121, 5.8%), and left-sidedness (1/121, 0.8%). The mean lumbar vertebral levels of the CVC bifurcation were L6.39 ± 0.41, L5.70 ± 0.35, L4.39 ± 0.42, L2.74 ± 0.38, and L6.4 in the normal, caudal-partial split, partial duplication, complete duplication, and left-sidedness types, respectively. The location of the CVC bifurcation, the relationship between the aortic trifurcation and the CVC bifurcation, and the location of the bilateral deep circumflex iliac veins with respect to the CVC bifurcation were significantly different among the right-sided types (P ≤ .001). Bilateral deep circumflex iliac veins joined to the ipsilateral common iliac veins and the CVC in the caudal-partial split and duplication types, respectively. The results of this study indicated that canine CVC variants may be frequent and should be considered during surgery or diagnostic imaging of the retroperitoneum.

Type Classification of Sudden Stratospheric Warming Based on Pre- and Postwarming Periods

Abstract In existing literature, sudden stratospheric warming (SSW) events have been typically defined as displacement or split types. Detailed reexamination of SSW evolution has revealed that an SSW event often alters its type before and after the central day of the warming event. On the basis of this observation, we objectively define three types of SSW using wave amplitude: displacement–displacement (DD) type, displacement–split (DS) type, and split–split (SS) type. The geopotential height (GPH) amplitude of zonal wavenumbers 1 and 2 averaged over 55°–65°N at 10 hPa was used as a criterion for the classification. If the amplitude of zonal wavenumber 1 is larger (smaller) than that of wavenumber 2 before and after the central day of SSW, the event is regarded as a DD (SS) type. If the amplitude of zonal wavenumber 1 is larger than that of wavenumber 2 before the central day but is smaller after that day, the event is regarded as a DS type. The above classification algorithm has been applied to both reanalysis data and model results. We observe that conventional split-type SSW events identified by previous studies can be categorized as either DS- or SS-type events, each type of which exhibits different evolution characteristics. In particular, they are distinctively different during the prewarming period. In the SS type, the characteristics of the conventional split type are more obvious, and the features that differ from those of the DD type are the most robust. The model results generally resemble the reanalysis data, particularly in the DD cases.

Types of die-punch fracture of the distal radius based on three-column theory

Objective To investigate the characteristics and types of die-punch fracture of the distal radius (DPFDR) based on three-column theory as well as its application value. Methods The imaging data of 560 cases of DPFDR were reviewed which had been treated at The Ninth People’s Hospital of Wuxi from June 2007 to June 2017. They were 305 males and 255 females, aged from 13 to 95 years, with an average of 46.4 years. According to the three-column theory, the 560 DPFDR cases were divided into a single column group and a double column group. According to the fracture site and morphology, the former was further characterized as volar, dorsal, split and collapse types while the latter as metaphyseal, articular surface and mixed types. After being familiarized with our new classification, 2 radiologists were asked to classify 100 cases of DPFDR independently. The inter-and intra-observer agreements were analyzed with Kappa statistics. Results There were 65 cases of single column DPFDR, including 3 ones of volar type, 13 ones of dorsal type, 14 ones of split type and 35 ones of collapse type; there were 495 cases of double column DPFDR, including 130 ones of metaphyseal type, 155 ones of articular surface type and 210 ones of mixed type. The intra-observer Kappa coefficient was 0.877-0.937 and the intra-observer kappa was 0.916-0.959, showing high agreement. Conclusions Due to differences in violence nature and intensity, wrist position and bony quality of the patient at the time of injury, axial violent transmission may cause different types of die-punch fracture at the intermediate column of the distal radius and different types of mild radial column fractures as well. As our new classification may well characterize the site and morphology of DPFDR, it has high consistency to guide surgical treatment and prognosis judgment. Key words: Radius; Fractures, bone; Diagnostic imaging; Three-column theory

A new classification and its value evaluation for intermediate column fractures of the distal radius

BackgroundIntermediate column fractures of the distal radius (ICF) are fractures only or mainly limited to the lunate fossa of the distal radius. There are no classification systems and its value evaluation for ICF in the literature.MethodsAccording to the characteristics of ICF, ICF were divided into the volar, dorsal, split, collapse, and collapse with split types. Inter- and intra-observer agreements were analyzed with kappa statistics. Seventy-four patients with ICF were retrospectively studied from January 2008 to June 2016. Surgical approach and reduction-fixation method were taken under the guidelines of the classification in 54 patients with displaced fractures, while conservative treatment was taken in 16 patients with non-obvious displaced fractures and 4 patients with displaced fractures who declined surgery.ResultsThe inter- and intra-observer kappa coefficients were 0.875~0.925 and 0.900~0.950, respectively. All patients were followed up for 13~36 months (average, 18.4 months). At the last follow-up, according to Gartland and Werley score of the functional recovery of wrist, all except 3 patients had excellent or good results (the excellent and good rate was 95.95%).ConclusionThe classification reflects the characteristics of ICF and may provide an important reference for choosing treatment and evaluating prognosis.

The performance of split and integrated types of air-source heat pump water heaters in South Africa

Renewable energy technologies that can provide optimum and cost-effective energy savings to mitigate global warming, energy crisis and to achieve energy efficiency continue to be of paramount importance. The present study focused on identifying critical parameters such as the volume of hot water drawn off; ambient temperature; relative humidity; refrigerant temperatures at the inlet and outlet of the compressor and condenser; and deterministic quantities such as time used, power consumption and coefficient of performance (COP) as indicators to benchmark the performance of both the split and integrated types of air-source heat pump (ASHP) water heaters. The basis for analysis was on two predominant scenarios: first-hour heating rating and the heating cycle due to controlled volume of hot water drawn-off wherein both the integrated and split types ASHP water heaters experienced vapour compression refrigeration cycles. A data acquisition system was constructed and implemented to monitor the performance of both systems. The results obtained during summer season showed that, under the scenario of 150 L hot water withdrawal, the average COP of the systems was 3.18 and 2.85 for the split and integrated types respectively. The average power consumed was 1.29 (split type) and 0.85 kW (integrated type). The times of operation were 84 minutes (split type) and 138 minutes (integrated type).

Structural and functional study of a simple, rapid, and label-free DNAzyme-based DNA biosensor for optimization activity.

Peroxidase-mimicking DNAzyme has a potential to self-assemble into a G-quadruplex and shows peroxidase activity. In comparison to proteins, peroxidase-mimicking DNAzyme is less expensive and more stable. Herein, it is used in fabricating non-labeling biosensors. This paper investigates the structural and functional properties of a DNA biosensor based on split DNAzyme with a detection limit in nM range (9.48 nM). Two halves of DNAzyme were linked by a complementary sequence of DNA target. Hybridization of the DNA target pulled two DNAzyme halves apart and peroxidase activity decreased. This study can be divided into 3 stages. First, the characteristics of DNAzyme were studied by Circular Dichroism technique and UV-Vis spectroscopy to find out DNAzyme's optimum activity. It is worth to note that some divalent cations were used to form G-quadruplex, in addition to common monovalent cations. Furthermore, the hemin incubation was also optimized. Secondly, the structural and functional properties of two types of split DNAzyme were compared with DNAzyme. Thirdly, the hybridization of DNA target was monitored. The results revealed that peroxidase activities of split types decreased by half without any specific conformational changes. Interestingly, the catalytic activities of split DNAzymes could be promoted by adding Mg2+ . Besides, it was demonstrated that the structure, peroxidation reaction, and DNA target hybridization of 2:2 and 3:1 split modes were almost alike. It was also illustrated that magnesium promoted the possibility of hybridization.

Multistate vector product hopfield neural networks

Several high-dimensional models of Hopfield neural networks, such as complex-valued and quaternionic Hopfield neural networks, have been proposed. However, it has been hard to construct three-dimensional models of Hopfield neural networks. A split type of vector product Hopfield neural network (VPHNN) was proposed as a special case of ordinary Hopfield neural networks. It is easier to construct split types of Hopfield neural networks than multistate types of ones, because the split types can be often regarded as special cases of ordinary ones. In the present work, we extend the split VPHNN to the multistate VPHNN. We define its energy and a primitive learning algorithm, the Hebbian learning rule. In addition, we prove the stability of multistate VPHNNs. Furthermore, we investigated the fundamentals of multistate VPHNNs, such as the storage capacity and noise tolerance, by computer simulations.

A Survey of the quantity and type of biological aerosols in selected wards of a teaching hospital in Ghazvin.

IntroductionBioaerosols are agents that can cause infection, allergy or induce other toxic effects in the human body. If the person exposed to such particles is not capable of their destruction or elimination from the body, the established chemical and physiological disorders can result in disease or death. The aim of this study was to assess the concentrations of bioaerosols in several wards of a teaching hospital.MethodsGiven that gas air-conditioners (split and window types) were used for ventilation in the eye operating room, internal intensive care unit, and the respiratory isolation room, these wards were selected for passive sampling. Sterile plates containing culture medium were exposed for two hours to the wards’ indoor ambient air. After this time, they were transferred to a lab to undergo incubation, colony count, and identification of the microorganisms. The data were analyzed using SPSS software, version 18, and the significance level of less than 0.05 was used.ResultsBased on our findings, the highest colony-forming bacterial unit was observed 22 cfu/plate/h in the eye operating room and, the highest colony-forming fungal unit was observed 4 cfu/plate/h in the internal intensive care unit. Based on the results of the differential tests, the most prevalent bacteria identified were Staphylococcus epidermidis (75%) in the air of eye operating room and Staphylococcus saprophyticus (52%) in the internal intensive care unit and isolation room. The most prevalent identified fungi in the air of selected wards were related to Alternaria alternata (43%), Aspergillus flavus (24%), Penicillium (36%) and Curvularia (21%) types. Based on Spearman’s correlation test, no significant relationship was observed between the factor of temperature and the number of fungal and bacterial colonies (r = 0.201, p = 0.42; r = −0.197, p = 0.41). Moreover, a meaningful relationship was observed only between the number of individuals and the bacterial colonies present in the air (r = 0.749, p = 0.0001).ConclusionComparing the number of diagnosed colonies by 25 cfu/plate/h value showed that the numbers of colonies in all samples were lower than the mentioned values. So, the air-conditioning systems’ performance in reducing the number of bioaerosols in the studied wards was satisfactory. However, since the remaining bacterial and fungal contamination can cause serious infections in patients, it is highly necessary that the cleaning intervals and replacement time points of such filters be programmed based on the number of individuals present in the wards and their active surgical hours.

Jumlah bakteri Staphylococcus aureus dan skor California Mastitis Test (CMT) pada susu kambing Peranakan Etawa akibat dipping ekstrak daun Babadotan (Ageratum conyzoides L.)

The aim of this research is to determine the effect of teat dipping of Ettawa crossbred goat using babadotan leaves (Ageratum conyzoides Linn.) extract on the number of Staphylococcus aureus in milk . The udder inflammation degree also was determined using California Mastitis Test (CMT). The treatments were post milking teat dipping using antiseptic solutions containing 1%, 3%, and 5% of babadotan leaves extract (T1, T2 and T3, respectively). Milk samples were collected at before treatment (H0) and on the day 3, 6 and 9 day of the treatments (H3, H6 and H9, respectively). Commercially antiseptic povidone iodine was used as positive control (K+). Experimental research design was completely randomized design (CRD) split plot types, with the different extract concentration as the main plot and the day of treatment as subplot. CMT scores was analyzed using Kruskal-Wallis test. The results showed that babadotan leaves extract 5% had the same effectiveness (p>0,05) with povidone iodine to reduce the number of Staphylococcus aureus in milk. All extract concentrations (1%, 3% and 5%) had the same effectiveness (H>c0,05 (3) ) to decrease the CMT scores by postmilking teat dip treatments for 9 days. Keywords: Teat dipping, Ageratum conyzoides (L)., Staphylococcus aureus, CMT score

Synthesis of the turbulent mixing in a rod bundle with vaned spacer grids based on the OECD-KAERI CFD benchmark exercise

The second international CFD benchmark exercise on turbulent mixing in a rod bundle has been launched by OECD/NEA, to validate relevant CFD (Computational Fluid Dynamics) codes and develop problem-specific Best Practice Guidelines (BPG) based on the KAERI (Korea Atomic Energy Research Institute) MATiS-H experiments on the turbulent mixing in a 5×5 rod array having two different types of vaned spacer grids: split and swirl types. For this 2nd international benchmark exercise (IBE-2), the MATiS-H testing provided a unique set of experimental data such as axial and lateral velocity components, turbulent intensity, and vorticity information. Blind CFD calculation results were submitted by twenty-five (25) participants to KAERI, who is the host organization of the IBE-2, and then analyzed and synthesized by comparing them with the MATiS-H data. Based on the synthesis of the results from both the experiments and blind CFD calculations for the IBE-2, and also by comparing with the IBE-1 benchmark exercise on the mixing in a T-junction, useful information for simulating this kind of complicated physical problem in a rod bundle was obtained. And some additional Best Practice Guidelines (BPG) are newly proposed. A summary of the synthesis results obtained in the IBE-2 is presented in this paper.

Split cord malformation types I and II: a personal series of 131 patients

A personal series of 131 patients with split cord malformation (SCM) operated on is presented. Age, gender, symptoms and signs, radiological and operative findings, complications, associated anomalies, outcome, and pathological specimens were analyzed. There were 88 girls (73 %) and 43 boys (27 %). The female predominance was slightly more remarkable in type I SCMs than in type II SCMs. The presenting symptoms can be summarized as skin lesions, spina bifida aperta, scoliosis or kyphoscoliosis, sphincter disturbance, foot deformities and weakness, and/or atrophy in the lower extremities. The ages of patients with neurological deficits and orthopedic deformities were significantly older than those without deficits (P = 0.030). The duration of symptoms was longer in the patients with neurological deficits and orthopedic deformities than that in those without deficits (P = 0.00095). In six patients, composite SCMs were present. Only one patient with a type II SCM did not have an associated spinal cord lesion. A type I SCM was more frequently encountered in patients with spina bifida (P < 0.0005). Transient postoperative complications were seen in 29 patients (22 %). There was no permanent complication. Retethered cord syndrome developed in five patients with a type I SCM. The risk of neurological and orthopedic deficits increases with the age of the patient. The risk of permanent deficit after surgery is very low. The whole spine must be examined for additional lesions. All patients should be surgically treated when diagnosed, especially before the development of orthopedic and neurological manifestations, and all associated lesions should also be treated at the same session.