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The eHealth sector has witnessed significant growth due to technological advancements, facilitating care delivery in patients' homes and moving away from traditional hospital settings. Blockchain and the Internet of Things (IoT) play pivotal roles in enhancing healthcare services, offering features such as remote patient monitoring, streamlined electronic medical record (EMR) management, drug traceability, and effective disease control, particularly during events like the COVID-19 pandemic. The growing utilization of IoT devices brings about security challenges, including concerns related to data integrity and device authentication. This paper proposes the integration of blockchain technology as a robust solution. Leveraging its decentralized and tamper-resistant features, blockchain establishes trust among diverse IoT devices, ensuring the integrity of IoT data. Additionally, smart contracts enhance device authentication, fortifying overall security by addressing vulnerabilities associated with centralization. Regarding the management of eHealth, this survey begins with an overview of the industry, highlighting IoT-related challenges in healthcare. It explores various IoT applications in eHealth and discusses how blockchain can effectively address obstacles in healthcare management through IoT. Notably, the paper provides insights into examining consensus algorithm parameters within blockchain systems, clarifying the methodology used to assess and optimize these critical components. The survey extends to a thorough review of existing research on integrating blockchain-based IoT in eHealth. Finally, it presents an overview of challenges and potential solutions for implementing blockchain-based IoT in the eHealth sector. This comprehensive survey aims to empower stakeholders by providing insights to enhance patient care in this dynamic and evolving field. [ABSTRACT FROM AUTHOR]

In this paper, neutronic calculations and the core analysis of the VVER-1000 reactor were performed using MCNP6 code together with both ENDF/B-VII.1 and ENDF/B-VIII libraries. The effect of thorium introduction on the neutronic parameters of the VVER-1000 reactor was discussed. The reference core was initially filled with enriched uranium oxide fuel and then fueled with uranium-thorium fuel. The calculations determine the delayed neutron fraction βeff, the temperature reactivity coefficients, the fuel consumption, and the production of the transuranic elements during reactor operation. βeff and the Doppler coefficient (DC) are found to be in agreement with the design values. It is found that the core loaded with uranium and thorium has lower delayed neutron fraction than the uranium oxide core. The moderator temperature coefficients of the uranium-thorium core are found to be higher than those of the uranium core. Results indicated that thorium has lower production of minor actinides (MAs) and transuranic elements (mainly plutonium isotopes) compared with the relatively large amounts produced from the uranium-based fuel UO2. [ABSTRACT FROM AUTHOR]

The present work studies the effect of introducing MOX fuel on Westinghouse AP1000 neutronic parameters. The neutronic calculations were performed by using the MCNP6 code with the ENDF/B-VII.1 library and the new release of the ENDF/B-VIII, the AP1000 core with three 235U enrichment zones (2.35%, 3.40%, and 4.45%). The obtained results showed that the simulated model for the AP1000 core satisfies the optimization criteria as a Westing- house reference. The results which included: effective multiplication factor, keff, delayed neutron fraction, beff, excess reactivity, rex, shutdown margin, temperature reactivity coefficients, whole core depletion, neutron flux, power peaking factor and core power density, were calculated and compared with the available published results. The keff in the cold zero power was found to be 1.20495 and 1.20247 with the ENDF/B-VII.1 and the ENDF/B-VIII libraries, respectively, which matches the value of 1.205 presented in the AP1000 Design Control Document for the UO2 fuel core. On the other hand, keff in the cold zero power was found to be 1.19988 and 1.19860 for MOX core with the ENDF/B-VII.1 and the ENDF/B-VIII libraries, respectively, which show good reception and confirm the safety of the design and efficient modeling of AP1000 reactor core. [ABSTRACT FROM AUTHOR]

In sandstone formations, the quartz particles integrate with drilling fluid solids and become part of the filter cake structure. As a result, the dissolution rate of the filter cake diminishes and reduces the removal efficiency. This paper presents a novel solution to overcome the challenges that restricts the filter cake removal process such as the presence of the quartz layer and the polymer coat. A multi-stage method for removing the filter cake from a wellbore is presented. The composition of the new formulation is; ammonium fluoride (NH4F), with a strong oxidizer, such as sodium bromate (NaBrO3) causes an exothermic reaction in the first stage, thereby removing the quartz layer and polymer coat in the filter cake by the in-situ generated HF acid. During the second stage for the barite-based filter cake, chelating agents combined with convertor catalysts were used to dissolve the barite. Solubility experiments were conducted to evaluate the efficiency at each stage in the filter cake removal process at 300 ºF and 500 psi. The experimental results showed that the formulation consisting of ammonium fluoride (NH4F), with a strong oxidizer (sodium bromate,NaBrO3), combined with exothermic reaction was able to generate HF in-situ, which in turn dissolved the quartz mineral and remove the polymer from the filter cake. [ABSTRACT FROM AUTHOR]

This work represents a method to stimulate illitic sandstone formations using in-situ generated hydrofluoric acid (HF) in the presence of thermochemicals. Using traditional mud acid for stimulating such reservoirs would cause a huge damage to the formation rather than enhancing its permeability. In this study, HF acid precursor reacts with an oxidizer in the presence of an exothermic reaction to generate HF acid downhole. Besides the high temperature generated inside the near-wellbore area, the pressure will build-up due to produced nitrogen gas from the thermochemicals reaction. The high pressure provides enough energy to flows back the well and removes any resulted precipitate. Firstly, the solubility of quartz and clay minerals in the new chemical mixture was tested. After that, core flooding tests were run for Scioto sandstone cores of 6-inch length and 1.5-inch diameter. Two different approaches were adopted for this treatment; (1) to remove the core damage and enhance its permeability using the acid generating fluids, (2) to stimulate the core using both the acid generating fluids and the thermochemicals. The core petrophysical and mechanical properties are evaluated before and after the acidizing process using core flooding tests, NMR scans and scratch tests. The core permeability got enhanced by about 37.5% after being treated with the acid generating fluids. The Inductively Coupled Plasma (ICP) analysis of the core flooding effluent showed that the total chelated amount of Si4+ ions from the core reached 49 mg. The scratch test showed a decrease in the Scioto core strength after the acid treatment by about 770 psi. Moreover, the core dynamic Young's modulus and Poisson's ratio were reduced by 550 ksi and 0.01 respectively. On the other hand, the NMR scanning for Scioto core showed an enhancement in the core total porosity after the acid treatment. The generated pressure pulse from the thermochemicals pushes the acid generated deeper into the formation and highly increased the stimulation process efficiency. Upon application of this new stimulation technology, the true production potential of sandstone reservoirs can be achieved, corrosivity will be minimized and handling hazardous chemicals (HF) will be avoided. • New method to generate in-situ HF acid was introduced. • Solubility experiments showed the effectiveness of the generated acid to react with both clays and quartz. • Coreflooding experiments showed good improvement in core permeability. • The generated acid created micro fractures in addition to its dissolving power. • The generated acid did not change that much the rock integrity. [ABSTRACT FROM AUTHOR]

Background: Tissue Doppler imaging (TDI) has provided an objective means to quantify global and regional ventricular functions with improved accuracy and greater reproducibility than conventional echocardiography. This study was conducted to assess right ventricular (RV) myocardial systolic activation by TDI in children with pulmonary arterial hypertension (PAH).Methods: Forty pediatric patients with PAH and 20 healthy controls, underwent standard echocardiogram and TDI. In the apical 4 chamber view the following regional parameters were evaluated in three different myocardial segments (RV basal lateral, basal septal and LV basal lateral): systolic (Sm), early- and late-diastolic (Em and Am) peak velocities. RV myocardial systolic activation delay was defined as the difference in time to peak TDI systolic velocities between the RV basal lateral wall and basal septal. In addition, RV end-diastolic and end-systolic areas were measured to calculate RV fractional area change (FAC).Results: Compared with the control group, pediatric patients with PAH showed reduced RV FAC; 37.6±14% versus 48±5% (P0.0024). The patients group showed lower myocardial peak velocities and a significant activation delay compared with controls (P0.0001). There was a significant negative correlation between RV myocardial systolic activation delay and RV FAC. RV myocardial systolic activation delay was even present in a subset of patients with normal FAC.Conclusions: In PAH, RV myocardial systolic activation was markedly delayed and showed significant negative correlation with the RV FAC. RV myocardial systolic activation delay could offer a unique approach to predict early RV dysfunction before the decline in RV FAC is evident. [ABSTRACT FROM PUBLISHER]

The mean number of biologics per patient was 1.6 (SD 1.4) A total of 309 (74.3%) patients were anti-TNF experienced, 59 (14.1%) patients had been exposed to anti-IL12/23 and 73 (17.5%) of them were treated with anti-integrin. Two hundred and fifty (60.2%) patients had undergone small bowel or colon resection prior to RVF diagnosis and 110 (26.4%) of them had a prior ostomy during CD course. Rectovaginal and anovaginal fistulizing disease (RVF) occurs in 10% of Crohn's disease (CD) patients and is a debilitating condition, often refractory to medical therapy. [Extracted from the article]

Long-Range Wide Area Network (LoRaWAN) is an open-source protocol for the standard Internet of Things (IoT) Low Power Wide Area Network (LPWAN). This work's focal point is the LoRa Multi-Armed Bandit decentralized decision-making solution. The contribution of this paper is to study the effect of the re-learning EXP3 Multi-Armed Bandit (MAB) algorithm with previous experts' advice on the LoRaWAN network performance. LoRa smart node has a self-managed EXP3 algorithm for choosing and updating the transmission parameters based on its observation. The best parameter choice needs previously associated distribution advice (expert) before updating different choices for confidence. The paper proposes a new approach to study the effects of combined expert distribution for each transmission parameter on the LoRaWAN network performance. The successful transmission of the packet with optimized power consumption is the pivot of this paper. The validation of the simulation result has proven that combined expert distribution improves LoRaWAN network's performance in terms of data throughput and power consumption. [ABSTRACT FROM AUTHOR]