A numerical modelling and simulation of core-scale sandstone acidizing process: a study on the effect of temperature

A wide and comprehensive understanding of the chemical reactions and mechanisms of HBF4 is crucial as it significantly influences its performance in stimulating a sandstone formation. In general, it is well-known that HBF4 is able to provide a deeper penetration into the sandstone matrix before being spent due to its uniquely slow hydrolysis ability to produce HF. In the present study, a 3D numerical modelling and simulation were conducted to examine the capability of HBF4 in enhancing the porosity and permeability of the sandstone matrix. The model is built in COMSOL® Multiphysics commercial software of computational fluid dynamics (CFD) to simulate the acid core flooding process on sandstone core. The model had been validated against the experimental data in the literature. The results matched with the measured plot data very well. The effect of temperature on the performance HBF4 sandstone acidizing is evaluated in this study. The simulation results indicated that at low temperature of 25 °C, HBF4 is not very effective, as justified in its poor porosity and permeability increments of only 1.07 and 1.23, respectively. However, at elevated temperatures, the porosity and permeability enhancement also become increasingly more significant, which showed 1.26 and 2.06, respectively, at 65 °C; and 1.67 and 7.06, respectively, at 105 °C. Therefore, one can conclude that HBF4 acid treatment performed better at elevated temperatures due to increased hydrolysis rate, which is a governing function in HBF4 sandstone acidizing. Overall, this model had provided a reliable alternative to optimize various other parameters of HBF4 acid treatment

Immune cell constitution in bone marrow microenvironment predicts outcome in adult ALL

As novel immunological treatments are gaining a foothold in the treatment of acute lymphoblastic leukemia (ALL), it is elemental to examine ALL immunobiology in more detail. We used multiplexed immunohistochemistry (mIHC) to study the immune contexture in adult precursor B cell ALL bone marrow (BM). In addition, we developed a multivariate risk prediction model that stratified a poor survival group based on clinical parameters and mIHC data. We analyzed BM biopsy samples of ALL patients (n = 52) and healthy controls (n = 14) using mIHC with 30 different immunophenotype markers and computerized image analysis. In ALL BM, the proportions of M1-like macrophages, granzyme B+CD57+CD8+ T cells, and CD27+ T cells were decreased, whereas the proportions of myeloid-derived suppressor cells and M2-like macrophages were increased. Also, the expression of checkpoint molecules PD1 and CTLA4 was elevated. In the multivariate model, age, platelet count, and the proportion of PD1+TIM3+ double-positive CD4+ T cells differentiated a poor survival group. These results were validated by flow cytometry in a separate cohort (n = 31). In conclusion, the immune cell contexture in ALL BM differs from healthy controls. CD4+PD1+TIM3+ T cells were independent predictors of poor outcome in our multivariate risk model, suggesting that PD1 might serve as an attractive immuno-oncological target in B-ALL.Peer reviewe

Multilevel Turbo Coded-Continuous Phase Frequency Shift Keying (MLTC-CPFSK) over satellite channels in space communication

In this paper, in order to improve bit error performance and bandwidth efficiency, we introduce a new type of Turbo coded modulation scheme, called Multilevel Turbo Coded-Continuous Phase Frequency Shift Keying (MLTC-CPFSK). The basic idea of multilevel coding is to partition a signal set into several levels and to encode separately each level by a proper component of the encoder. In MLTC-CPFSK, to provide phase continuity of the signals, Turbo encoder and Continuous Phase Encoder (CPE) are serially concatenated at the last level, while all other levels consist of only a turbo encoder. Therefore, the proposed system contains more than one turbo encoder/decoder blocks in its structure. The parallel input data sequences are encoded by our multilevel scheme and mapped to CPFSK signals. Then these modulated signals are passed through AWGN and fading channels. At the receiver side, input sequence of first level is estimated from the first turbo decoder. Then the other input sequences are computed using the estimated input bit streams of previous levels. Simulation results are drawn for 4CPFSK two-level turbo codes over AWGN, Rician, and Rayleigh channels for three iterations while frame sizes are chosen as 100 and 1024. Higher error performances are obtained from various type of MLTC-CPFSK systems compared to Trellis Coded CPFSK systems

Evaluation of Cybercrime Economy via MCDM and Decision Tree Approaches: The Case of Zonguldak

One of the most important economic problems that developed/ing countries are facing today is the informal economy. Unregistered economic activities are generally defined as all economic activities that are not included in national accounts. The informal economy has an informal structure as well as a criminal structure. Cyber-attack/s (CA) are increasing day by day as an important part of the informal economy due to the economic effects they produce. Credit card fraud, emptying a bank account, cryptolocker viruses that can be used to encrypt data on the user’s computer, the use of websites and e-commerce sites such as DDOS attacks, espionage, information smuggling, and many new computing crimes can be given as examples in this field. This study aims to evaluate the relations/determiners of CA-damages and information technology (IT) investments to firms’ economics and present the findings to the researchers/decision makers. In this sense, IT investments and CA/CA costs to 321 Zonguldak firms having more than 20 employees in 2016 have been surveyed by Turkish Statistical Institute. According to CA-damage severity indexes generated via TOPSIS, statistical methods and decision tree approaches supported by regression analysis are used in the analysis. According to the analysis, CA-damage increased as IT investments increased. IT investments dimensions’ existence of “website/mobile applications” and “IT policy implementation” accepted the main CA-damage determiners. Meanwhile, the firm’s less usage of firewalls/IPS/IDS indicates that CA are not fully understood, and the security policies’ application is also important along with its preparation. © 2020, Springer Nature Switzerland AG