Hybrid continuum-discrete simulation of granular impact dynamics

Granular impact -- the dynamic intrusion of solid objects into granular media -- is widespread across scientific and engineering applications including geotechnics. Existing approaches for simulating granular impact dynamics have relied on either a pure discrete method or a pure continuum method. Neither of these methods, however, is deemed optimal from the computational perspective. Here, we introduce a hybrid continuum-discrete approach, built on the coupled material-point and discrete-element method (MP-DEM), for simulating granular impact dynamics with unparalleled efficiency. To accommodate highly complex solid-granular interactions, we enhance the existing MP-DEM formulation with three new ingredients: (i) a robust contact algorithm that couples the continuum and discrete parts without any interpenetration under extreme impact loads, (ii) large deformation kinematics employing multiplicative elastoplasticity, and (iii) a trans-phase constitutive relation capturing gasification of granular media. For validation, we also generate experimental data through laboratory measurement of the impact dynamics of solid spheres dropped onto dry sand. Simulation of the experiments shows that the proposed approach can well reproduce granular impact dynamics in terms of impact forces, intrusion depths, and splash patterns. Further, through parameter studies on material properties, model formulations, and numerical schemes, we identify key factors for successful continuum-discrete simulation of granular impact dynamics

Erosion and Transport of Dry Soil Bed by Collisional Granular Flow: Insights From a Combined Experimental–Numerical Investigation

Collision-induced stresses on soil beds under granular geophysical flows have been demonstrated to be highly erosive. However, it remains mostly elusive as to how a collisional granular flow erodes and transports soil bed material. This paper presents a combined experimental and numerical investigation into the mechanisms underlying collision-induced erosion and transport of dry soil beds. A series of flume experiments are conducted where collisional granular flows erode dry sand beds under varied conditions. The experiments are then back-analyzed using a hybrid continuum–discrete simulator to gain physical insight into the erosion and transport processes. Results show that the key mechanism of collision-induced erosion and transport is the retexturing of the soil bed surface. This implies that bed morphology, which has often been overlooked in mobility and hazard assessments, has profound effects on erosion and transport potential. Further, contrary to most existing models that assume all the eroded bed volume is carried away by granular flow, it is found that only up to 80% of the eroded material is transported. Also found is that the collisional stresses of the monodisperse grains in this study follow the Pareto distribution in which 80% of differences in the outcomes are due to 20% of causes. This finding suggests that there is measurable certainness in a seemingly random process of coarse grain collisions with an erodible soil bed

RTL Generation of Channel Architecture Templates for a Template-based SoC Design Flow

In this paper, we propose the design methodology for communication channel templates from formal specification to RTL description. In this flow, design and verification start from one source, LTL property. We constructed LTL-to-TRS, which is translator from LTL property sets to Bluespec term-rewriting system (TRS) description. And, we use a Bluespec compiler as a synthesizer from TRS to RTL. Also, to match the implementation with the formal specification, we use a VIS solver as a model checker. And then, channel instances generated by proposed design method are transformed into channel template-generators for communication channel library. These channel templates can be used in DSE process in SoC design flow.This work was supported by ISRC of SNU, BK21, SystemIC 2010, IP/SoC of Seoul, and IDEC, Korea

Advances in large PECVD processing technology up to Gen 11 for TFT LCD and OLED

Recent surging demands for larger (\u3e50”) TVs rapidly driving display processing technologies toward bigger substrate sizes up to 10m2 range. Meanwhile, high performance displays (OLED TV, iPad, iMac and 4K monitors…) have stretched a-Si mobility (85% LCD TVs in the world, supported recent starting of over a dozen largest TV factories worldwide Gen 8.5 and above, in particular enabled \u3e95% of advanced IGZO metal-oxide TFT display products including all latest OLED TVs, Apple iPads, iMac 5K or 4K displays, Microsoft Surface Pro 4, as well as major brand 4K or 8K monitors. Please click Additional Files below to see the full abstract

The Largest Known Survival Analysis of Patients with Brain Metastasis from Thyroid Cancer Based on Prognostic Groups

To analyze the clinical features and prognostic factors associated with the survival of patients with a very rare occurrence of brain metastasis (BM) from differentiated thyroid cancer (DTC).A total of 37 patients with DTC who were diagnosed with BM between 1995 and 2014 were included. We reviewed the clinical characteristics, treatment modalities, and image findings of BM. Factors associated with survival were evaluated, and the patients were divided into three prognostic groups (Groups A, B, and C) for comparative analysis.The median age at BM was 63 years, and the median time from initial thyroid cancer diagnosis to BM was 3.8 years. The median survival and the 1-year actuarial survival rate after BM were 8.8 months and 47%, respectively. According to univariate and multivariate analyses, four good prognostic factors (GPFs) were identified including age ≤ 60 years, PS ≤ ECOG 2, ≤ 3 BM sites, and without extracranial metastasis prior to BM. Three prognostic groups were designed based on age and number of remaining GPFs: patients ≤ 60 years of age with at least 2 GPFs (Group A) had the most favorable prognosis with a median survival of 32.8 months; patients ≤ 60 years of age with fewer than 2 GPFs and those > 60 years of age with at least 2 GPFs (Group B) had an intermediate prognosis with a median survival of 9.4 months; and patients > 60 years of age with fewer than 2 GPFs (Group C) had the least favorable prognosis with a median survival of 1.5 months.The survival of patients with BM form DTC differed among the prognostic groups based on the total number of good prognostic factors

HER2, estrogen receptor-negative metastatic hidradenocarcinoma: identification of TP53 mutation in both primary and cell-free DNA

Hidradenocarcinoma is an extremely rare cutaneous skin carcinoma which arise from the sweat gland. There are several report about potential targets in this rare disease including estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2). A 53-year-old man who presented with a slowly growing mass on the left thumb which was pathologically confirmed of HER2 negative, ER negative hidradenocarcinoma. At the time of presentation, the patient had metastatic lesions to lung and axillary lymph nodes. The patient received several lines of palliative chemotherapy and radiotherapy, but died of the disease progression. We identified TP53 G245S mutation in both primary tumor specimen and cell-free based targeted sequencing. Herein, we report on a very rare case of metastatic hidradenocarcinoma with TP53 G245S mutation but no other treatable targets from clinical sequencing, which pursued an aggressive clinical course

A Long Term Results of External Beam Radiation Therapy in Hemophilic Arthropathy of the Ankle in Children

Bleeding into joint space is critical to develop hemophilic arthropathy. To reduce the frequency of bleeding in the ankle joint of children with hemophilic arthropathy, low dose external beam irradiation was performed for 37 patients. Among them, 35 patients followed-up for longer than 1 yr (median 87 months) were enrolled for analysis. The average number of bleedings per month was 3.6 during one year prior to radiation therapy. After radiation therapy, it was decreased to 2.1 during the first year, after then it was maintained in the range of 1.0 to 1.5 until the tenth year. The bleeding frequency was reduced to 42% at the first year and it was maintained in the range of 58% to 73% from the second to the tenth year. Especially the patients who had 3 or more bleedings per month, and who had MRI score more than 3 showed significant decreases. During the follow-up period, growth disturbances and secondary malignancies were not found. External beam radiotherapy can be considered for the hemophilic patients with surgical or isotope therapies are not amenable

Tristetraprolin inhibits the growth of human glioma cells through downregulation of urokinase plasminogen activator/urokinase plasminogen activator receptor mRNAs

Urokinase plasminogen activator (uPA) and urokinase plasminogen activator receptor (uPAR) play a major role in the infiltrative growth of glioblastoma. Downregulatoion of the uPA and uPAR has been reported to inhibit the growth glioblastoma. Here, we demonstrate that tristetraprolin (TTP) inhibits the growth of U87MG human glioma cells through downregulation of uPA and uPAR. Our results show that expression level of TTP is inversely correlated with those of uPA and uPAR in human glioma cells and tissues. TTP binds to the AU-rich elements within the 3' untranslated regions of uPA and uPAR and overexpression of TTP decreased the expression of uPA and uPAR through enhancing the degradation of their mRNAs. In addition, overexpression of TTP inhibited the growth and invasion of U87MG cells. Our findings implicate that TTP can be used as a promising therapeutic target to treat human glioma

Establishment of a Disease-Specific Graded Prognostic Assessment for Hepatocellular Carcinoma Patients with Spinal Metastasis

Background/AimsHepatocellular carcinoma (HCC) patients with spinal metastasis (SM) show heterogeneous lengths of survival. In this study, we develop and propose a graded prognostic assessment for HCC patients with SM (HCC-SM GPA).Methods : We previously reported the outcomes of 192 HCC patients with SM who received radiotherapy from April 1992 to February 2012. Prognostic factors that significantly affected survival in that study were used to establish the HCC-SM GPA. Validation was performed using an independent cohort of 63 patients recruited from September 2011 to March 2016.Results : We developed the HCC-SM GPA using the following factors: Eastern Cooperative Oncology Group performance status (0–2, 0 point; 3–4, 1 point), controlled primary HCC (yes, 0 point; no, 2 points), and extrahepatic metastases other than bone (no, 0 point; yes, 1 point). Patients were stratified into low (GPA=0), intermediate (GPA=1 to 2), and high risk (GPA=3 to 4). When applied to the validation cohort, the HCC-SM GPA determined median survival durations of 13.6, 4.8, and 2.6 months and 1-year overall survival rates of 58.3%, 17.8%, and 7.3% for the low-, intermediate-, and high-risk patient groups, respectively (p<0.001).Conclusion : sOur newly proposed HCC-SM GPA successfully predicted survival outcomes