Search

Waterflooding of hydrocarbon deposits is an urgent problem for the oil and gas industry of Ukraine. In the process of active inflow of both edge-water and bottom water into productive reservoirs, significant hydrocarbon reserves are trapped. This results in low final hydrocarbon recovery factors. The process of watering production wells is natural, but this process must be controlled. To improve the efficiency of development of natural gas fields with bottom water, additional research was conducted using digital modeling. Based on a 3D model, the influence of penetration ratio in gas and water bearing formations on ultimate gas recovery is investigated. For the calculations, the penetration ratio was taken as 20%, 40%, 60%, 80%, and 100%. According to the modeling results, a significant impact of the penetration ratio on the efficiency of hydrocarbon production was found. According to the studies, it was found that with an increase the penetration ratio, the duration of the period of waterless operation of wells decreases. It should be noted that the greater the penetration ratio, the lower the gas recovery factor at the time of the breakthrough of the bottom water to the perforation interval. In addition, according to the studies, it was found that the smaller the penetration ratio, the greater the height of the cone of bottom water, as well as the larger the base of the cone. At full reservoir penetration, there is practically no cone formation process. In this case, the bottom water immediately enters the lower perforations of the production well and thus complicates its operation. In the short term, the flowing process is stopped and the well is shut down due to the failure to ensure the conditions for the removal of the gas-liquid mixture from the bottom hole. Based on the results of the calculations, the optimal penetration ratio in gas condensate deposits with bottom water was determined. According to the statistical processing of the calculated data, the optimal penetration ratio is 60.6%. The results of the research are aimed at improving the theoretical understanding of cone formation processes and for practical application in the mining industry in the development of natural gas fields with bottom water.

Waterflooding of hydrocarbon deposits is an urgent problem for the oil and gas industry of Ukraine. In the process of active inflow of both edge-water and bottom water into productive reservoirs, significant hydrocarbon reserves are trapped. This results in low final hydrocarbon recovery factors. The process of watering production wells is natural, but this process must be controlled. To improve the efficiency of development of natural gas fields with bottom water, additional research was conducted using digital modeling. Based on a 3D model, the influence of penetration ratio in gas and water bearing formations on ultimate gas recovery is investigated. For the calculations, the penetration ratio was taken as 20%, 40%, 60%, 80%, and 100%. According to the modeling results, a significant impact of the penetration ratio on the efficiency of hydrocarbon production was found. According to the studies, it was found that with an increase the penetration ratio, the duration of the period of waterless operation of wells decreases. It should be noted that the greater the penetration ratio, the lower the gas recovery factor at the time of the breakthrough of the bottom water to the perforation interval. In addition, according to the studies, it was found that the smaller the penetration ratio, the greater the height of the cone of bottom water, as well as the larger the base of the cone. At full reservoir penetration, there is practically no cone formation process. In this case, the bottom water immediately enters the lower perforations of the production well and thus complicates its operation. In the short term, the flowing process is stopped and the well is shut down due to the failure to ensure the conditions for the removal of the gas-liquid mixture from the bottom hole. Based on the results of the calculations, the optimal penetration ratio in gas condensate deposits with bottom water was determined. According to the statistical processing of the calculated data, the optimal penetration ratio is 60.6%. The results of the research are aimed at improving the theoretical understanding of cone formation processes and for practical application in the mining industry in the development of natural gas fields with bottom water. [ABSTRACT FROM AUTHOR]

[Background] The Japanese government anticipated refill prescriptions to reduce medical expenditures by 47 billion yen, but the actual reduction was only approximately 7 billion yen. We have previously reported that refill prescriptions accounted for 0.5% of total prescriptions filled at insurance pharmacies in Tokyo. This study expanded our trend analysis of refill prescriptions to the Kanto region, and compared the number and percentage of refill prescriptions issued by large university hospitals and other hospitals/clinics. [Methods] We analyzed refill prescriptions dispensed between April 2022 and June 2023 at Nihon Chouzai pharmacies within the Kanto region. The study variables included patient sex, age, number of refill prescriptions, and hospital type. [Results] In the Kanto region, Chiba had the highest number of refill prescriptions, followed by Tokyo and Kanagawa. As of June 2023, the number (percentage) of refill prescriptions was 5,718 (6.51%) in Chiba, 1,475 (0.45%) in Tokyo, and 312 (0.45%) in Kanagawa. Refill prescriptions were issued by 15 university hospitals during the study period, but were predominantly used by two university hospitals located in Chiba and Tokyo. [Discussion] The use of refill prescriptions in the Kanto region was especially high in Chiba. Refill prescriptions were also used in Tokyo, but were less common in other prefectures. Although a university hospital in Chiba was actively issuing refill prescriptions, many university hospitals hesitated to use. Future implementation and utilization of refill prescriptions may not only reduce medical expenditures, but also demonstrate the active engagement of pharmacies and pharmacists in medical care. [ABSTRACT FROM AUTHOR]

Pest control is essential for increasing agricultural production. Agricultural drones with spraying systems for pest control have generated great interest among farmers. However, spraying systems installed on unmanned aerial vehicles, like any other sprayer, can cause damage to the environment due to drift of the agent. Air induction (AI) nozzles are known to produce less drift (e.g., larger spray drops) than other nozzles, but there is a lack of research analyzing their effectiveness in combination with drones. In this study, AI and flat fan nozzles were installed on drones to evaluate their spray and pest control performance. Aerial spraying was conducted on rice and soybeans to measure the coverage and penetration ratio and analyze the crop production as well as the crop damage due to pests and diseases. The drone flight was conducted at an altitude of 3 m and a velocity of 2 m/s. Spray droplets were collected using water-sensitive paper at two heights above the soil surface. The experiments showed that the crop coverage with the AI nozzle was 130% higher than that with the flat fan nozzle. The drift reduction of AI nozzles increased the coverage of spray droplets. But the difference in the penetration ratios, which is the ratio of agents to be delivered inside the crop, was not significant between the nozzles. Also, there was no significant difference in crop yield and pest control efficacy. Consequently, the performance of the AI nozzle did not show differences from that of the XR nozzle, except for coverage. However, the AI nozzle raised less drift, so it should be considered for use in aerial control. [ABSTRACT FROM AUTHOR]

[Background] The April 2022 revision of medical fees included prescription format changes and the implementation of a refill prescription system that enables patients with stable symptoms to repeatedly use prescriptions for a specified duration under appropriate coordination between physicians and pharmacists. To investigate the dissemination of refill prescriptions a year after their implementation, this study examined their trends using Nihon Chouzai prescription data from April 2022 to June 2023. [Methods] The study focused on prescriptions with a "refillable" checkbox that were filled at Nihon Chouzai pharmacies within Tokyo that had opened by March 2022. Patient sex, age, number of refill prescriptions, and drug types were analyzed. [Results and Discussion] We identified 17,561 refill prescriptions filled at 148 pharmacies during the study period. There were 10,226 prescriptions with two refills and 7,335 prescriptions with three refills. The pharmacies initially filled 199 refill prescriptions in April 2022, and subsequently increased to 1,369 in October 2022 and 1,542 in April 2023. Among the drug types, the largest number of refill prescriptions was 4,102 for cardiovascular agents. Refill prescriptions were mainly dispensed for long-term medications such as cardiovascular agents, other metabolic agents, and hormones (including antihormones). This differed from regular prescriptions, which were mainly dispensed for cardiovascular agents, digestive organ agents, and sensory organ agents. Refill prescription numbers gradually increased following their introduction in April 2022. However, this number reached 1,542 in December (0.48% of total prescriptions) and remained relatively unchanged until June 2023. Future trends in refill prescriptions should be closely watched. [ABSTRACT FROM AUTHOR]

Pest control is essential for increasing agricultural production. Agricultural drones with spraying systems for pest control have generated great interest among farmers. However, spraying systems installed on unmanned aerial vehicles, like any other sprayer, can cause damage to the environment due to drift of the agent. Air induction (AI) nozzles are known to produce less drift (e.g., larger spray drops) than other nozzles, but there is a lack of research analyzing their effectiveness in combination with drones. In this study, AI and flat fan nozzles were installed on drones to evaluate their spray and pest control performance. Aerial spraying was conducted on rice and soybeans to measure the coverage and penetration ratio and analyze the crop production as well as the crop damage due to pests and diseases. The drone flight was conducted at an altitude of 3 m and a velocity of 2 m/s. Spray droplets were collected using water-sensitive paper at two heights above the soil surface. The experiments showed that the crop coverage with the AI nozzle was 130% higher than that with the flat fan nozzle. The drift reduction of AI nozzles increased the coverage of spray droplets. But the difference in the penetration ratios, which is the ratio of agents to be delivered inside the crop, was not significant between the nozzles. Also, there was no significant difference in crop yield and pest control efficacy. Consequently, the performance of the AI nozzle did not show differences from that of the XR nozzle, except for coverage. However, the AI nozzle raised less drift, so it should be considered for use in aerial control.

The scientific prediction of the TBM penetration rate is of great significance to the selection of hydraulic tunnel construction methods, construction schedule and cost estimation. In view of the high nonlinearity, fuzziness and complexity of TBM excavation process, and in order to improve the prediction accuracy and computational efficiency, the partial least squares regression (PLSR) has been applied to extract the principal components of the influencing parameters. Then the deep neural network (DNN) is employed to train and forecast the TBM penetration rate. A prediction model of TBM penetration rate based on the coupled method of PLSR and DNN is proposed. Based on the measured data of the double-shield TBM construction of a water conveyance tunnel in the Lanzhou water source construction project, six impact parameters including the rock uniaxial compressive strength, rock uniaxial tensile strength, cutter head thrust, cutter head speed, rock mass integrity coefficient and rock Cerchar abrasiveness index are selected to verify the prediction reasonability of the model. The fitting and prediction accuracy of the different prediction methods are compared and analyzed. The research results show that the PLSR can effectively overcome the problem of multiple collinearity between the independent variables. The extracted principal components are trained as the input layer of the DNN, which simplifies the structure of the neural network. The PLSR-DNN coupled model effectively avoids the over-fitting and inadequate fitting problems. It has the characteristics of fast convergence, stable solution and high fitting accuracy. The average relative fitting error of the PLSR-DNN prediction model is 2.96%, and the average relative prediction error is 3.27%. The fitting accuracy and prediction accuracy of the PLSR-DNN prediction model is significantly higher than those of PLSR model alone, BP neural network model and SVR model, respectively.

An important component of the variable renewable generation (VRG) integration in Romanian power grid represents the wind and solar curtailment energy due to the impact it can have on economics. This paper performs a quantitative assessment of both VRG penetration and curtailment ratio in Romanian grid using the new tool proposed in specialty literature named “C-P map”. It was only calculated the penetration ratio, for the curtailment ratio only being made interesting scenarios due to the lack of official data. This has allowed obtaining images of principle regarding near future tendency for the national power network, providing help in planning and decision making in order to optimize the VRG curtailment level and secure grid operating.

An important component of the variable renewable generation (VRG) integration in Romanian power grid represents the wind and solar curtailment energy due to the impact it can have on economics. This paper performs a quantitative assessment of both VRG penetration and curtailment ratio in Romanian grid using the new tool proposed in specialty literature named "C-P map". It was only calculated the penetration ratio, for the curtailment ratio only being made interesting scenarios due to the lack of official data. This has allowed obtaining images of principle regarding near future tendency for the national power network, providing help in planning and decision making in order to optimize the VRG curtailment level and secure grid operating. [ABSTRACT FROM AUTHOR]

Intelligent Transportation Systems (ITSs) utilize Vehicular Ad-hoc Networks (VANETs) to collect, disseminate, and share data with the Traffic Management Center (TMC) and different actuators. Consequently, packet drop and delay in VANETs can significantly impact ITS performance. Feedback-based eco-routing (FB-ECO) is a promising ITS technology, which is expected to reduce vehicle fuel/energy consumption and pollutant emissions by routing drivers through the most environmentally friendly routes. To compute these routes, the FB-ECO utilizes VANET communication to update link costs in real-time, based on the experiences of other vehicles in the system. In this paper, we study the impact of vehicular communication on FB-ECO navigation performance in a large-scale real network with realistic calibrated traffic demand data. We conduct this study at different market penetration rates and different congestion levels. We start by conducting a sensitivity analysis of the market penetration rate on the FB-ECO system performance, and its network-wide impacts considering ideal communication. Subsequently, we study the impact of the communication network on system performance for different market penetration levels, considering the communication system. The results demonstrate that, for market penetration levels less than 30%, the eco-routing system performs adequately in both the ideal and realistic communication scenarios. It also shows that, for realistic communication, increasing the market penetration rate results in a network-wide degradation of the system performance.

Data on the distribution of voriconazole (VRC) in the human peritoneal cavity are sparse. This prospective study aimed to describe the pharmacokinetics of intravenous VRC in the peritoneal fluid of critically ill patients. A total of 19 patients were included. Individual pharmacokinetic curves, drawn after single (first dose on day 1) and multiple (steady-state) doses, displayed a slower rise and lower fluctuation of VRC concentrations in peritoneal fluid than in plasma. Good but variable penetration of VRC into the peritoneal cavity was observed, and the median (range) peritoneal fluid/plasma ratios of the area under the concentration-time curve (AUC) were 0.54 (0.34 to 0.73) and 0.67 (0.63 to 0.94) for single and multiple doses, respectively. Approximately 81% (13/16) of the VRC steady-state trough concentrations ( C min,ss ) in plasma were within the therapeutic range (1 to 5.5 μg/mL), and the corresponding C min,ss (median [range]) in peritoneal fluid was 2.12 (1.39 to 3.72) μg/mL. Based on the recent 3-year (2019 to 2021) surveillance of the antifungal susceptibilities for Candida species isolated from peritoneal fluid in our center, the aforementioned 13 C min,ss in peritoneal fluid exceeded the MIC 90 of C. albicans, C. glabrata, and C. parapsilosis (0.06, 1.00, and 0.25 μg/mL, respectively), which supported VRC as a reasonable choice for initial empirical therapies against intraabdominal candidiasis caused by these three Candida species, prior to the receipt of susceptibility testing results., Competing Interests: The authors declare no conflict of interest.

As the share of VRE (variable renewable energy) has grown rapidly, curtailment issues have arisen worldwide. This paper evaluates and compares curtailment situations in selected countries using an objective and quantitative evaluation tool named the " C-E map " (curtailment-energy share map). The C-E map is a correlation map between curtailment ratios that mean curtailed wind (or solar) energy per available energy and energy shares of wind (or solar). The C-E map can draw a historical trend curve in a given country/area, as an at-a-glance tool to enable historical and/or international comparison. The C-E map also can classify the given countries/areas into several categories, according to the current levels of curtailment ratio and historical trends. The C-E map helps institutional and objective understanding of curtailment for non-experts including policy makers. • Curtailment is one of the most important issues for wind and solar integration. • Global curtailment data in Europe, North America, China and Japan was evaluated. • Curtailment ratio does not always increase as wind and solar share increases. • Some countries/areas decreased curtailment ratio by enhancing of flexibility resource. • C-E (Curtailment - Energy Share) Map can help to grab historical trend of curtailment. [ABSTRACT FROM AUTHOR]

Abstract: Background: ECMO (extracorporeal membrane oxygenation) is increasingly used in severe hemodynamic compromise and cardiac arrest (CA). Pulmonary infections are frequent in these patients. Venoarterial (VA) ECMO decreases pulmonary blood flow and antibiotic availability in lungs during VA ECMO treated CA is not known. We aimed to assess early vancomycin, amikacin and gentamicin concentrations in the pulmonary artery as well as tracheal aspirate and to determine penetration ratios of these antibiotics to lung tissue in a pig model of VA ECMO treated CA. Methods: Twelve female pigs, body weight 51.5 ± 3.5 kg, were subjected to prolonged CA managed by different modes of VA ECMO. Anesthetized animals underwent 15 min of ventricular fibrillation (VF) followed by continued VF with ECMO flow of 100 mL/kg/min. Immediately after institution of ECMO, a 30 min vancomycin infusion (10 mg/kg) was started and amikacin and gentamicin boluses (7.5 and 3 mg/kg, respectively) were administered. ECMO circuit, aortic, pulmonary arterial, and tracheal aspirate concentrations of antibiotics were measured at 30 and 60 min after administration; penetration ratios were calculated. Results: All 30 min antibiotic concentrations and 60 min concentration for gentamicin in the pulmonary artery were no different than the aorta. However, the 60 min pulmonary artery vancomycin and amikacin values were significantly higher than aortic, 19.8 (14.3–21.6) vs. 17.6 (14.2–19.0) mg/L, p = 0.009, and 15.6 mg/L (11.0–18.6) vs. 11.2 (10.4–17.2) mg/L, p = 0.036, respectively. One hour penetration ratios were 18.5% for vancomycin, 34.9% for gentamicin and 38.8% for amikacin. Conclusion: In a pig model of VA ECMO treated prolonged CA, despite diminished pulmonary flow, VA ECMO does not decrease early vancomycin, gentamicin, and amikacin concentrations in pulmonary artery. Within 1 h post administration, antibiotics can be detected in tracheal aspirate in adequate concentrations. [Copyright &y& Elsevier]

The world today is plagued with problems of increased transmission and distribution (T&D) losses leading to poor reliability due to power outages and an increase in the expenditure on electrical infrastructure. To address these concerns, technology has evolved to enable the integration of renewable energy sources (RESs) like solar, wind, diesel and biomass energy into small scale self-governing power system zones which are known as micro-grids (MGs). A de-centralised approach for modern power grid systems has led to an increased focus on distributed energy resources and demand response. MGs act as complete power system units albeit on a small scale. However, this does not prevent them from large operational sophistication allowing their independent functioning in both grid-connected and stand-alone modes. MGs provide greater reliability as compared to the entire system owing to the large amount of information secured from the bulk system. They comprise numerous sources like solar, wind, diesel along with storage devices and converters. Several modeling schemes have been devised to reduce the handling burden of large scale systems. This paper gives a detailed review of MGs and their architecture, state space representation of wind energy conversion systems & solar photovoltaic (PV) systems, operating modes and power management in a MG and its impact on a distribution network. [ABSTRACT FROM AUTHOR]

Abstract: A newly derived nonlinear flow numerical simulator was used to study on the diamond-shape inverted nine-spot well pattern based on laboratory experiment and actual field data. The optimum artificial fracture penetration ratio, flow conductivity, and condition of converting the corner-wells to injection wells were presented on the basis of 37 concept model well plans. Finally, the formation pressure gradient distributions of different well plans were provided and analyzed. [Copyright &y& Elsevier]

Abstract: Ambient air emissions of sub-micron particles infiltrate into indoor environments and play a major role in indoor air quality. Discriminating between particles of indoor vs. outdoor origin is therefore essential when assessing indoor air pollutant levels and characteristics. Outdoor/indoor relationships of traffic-derived nanoscaled particulates (PM1 and black carbon) were determined in a typical Mediterranean environment. Results evidenced the major impact of outdoor vehicular traffic emissions on indoor particulates: despite windows remaining closed at all times, 70% of indoor BC and 73% of indoor PM1 originated from outdoor emissions. This was probably due to due to inadequate insulation of the building. Outdoor/indoor penetration ratios were relatively constant for BC (1.29 ± 0.08) but not for PM1 (1.95 ± 0.38), suggesting it is advisable to monitor the variability of penetration factors over time. Particle infiltration seemed to depend not only on physical barriers (building envelope, ventilation systems, etc.), but also on the physico-chemical properties of the particulates. Printing and photocopying contributed with 25–30% (546 ng m−3) of total indoor BC. Dust re-suspension by worker passage was the main indoor source of PM1 (15–20%, 1.1 μg m−3). [Copyright &y& Elsevier]

The stress field developed in the human lumbar vertebral bone due to the presence of transpedicular fixation screws is studied in an attempt to quantify the force required to pull the screw out of the bone. The study is focused on the pure pull-out phenomenon, namely the case in which the external loads act parallel to the longitudinal axis of the screw. The parameters considered are the penetration ratio, i.e. the ratio of the screw length divided by the distance from the posterior pedicle entrance site to the anterior vertebral cortex, and the filling ratio, i.e. the ratio of the major diameter of the screw divided by the transverse diameter of the pedicle. The study is carried out numerically with the aid of the finite element method. The analysis takes into account both the variation of the mechanical properties of the bone in terms of the distance from its surface as well as the geometrical details of a typical transpedicular screw. The results of the analysis are compared with existing experimental data from the literature and the comparison is very satisfactory. [ABSTRACT FROM AUTHOR]

In glutenite reservoirs, hydraulic fracture surfaces are always rough due to the presence of gravels. The fracture surface roughness significantly affects the proppant transport, settlement, and supporting effectiveness during and after hydraulic fracturing. To reduce the fracture surface roughness in fracturing glutenite reservoirs, the cyclic injection was proposed and verified with hydraulic fracturing experiments on glutenite samples. After fracturing in experiments, a laser scanning system was used to scan and extract the fracture surface 3D data, of which the fracture surfaces were characterized with 5 parameters. Experimental results showed that the cyclic injection reduced the fracture asperity height by 30–70%, the standard deviation of the normal fracture asperity height reduced by over 52%. Meanwhile, the cyclic injection increased the penetration ratio (the number of those penetrated by hydraulic fractures divided by the total number of gravels along the fracture path) by 20% for gravel size of 2−6 mm and 30% for gravel size of 6−25 mm. The mechanism of the cyclic injection reducing fracture surface roughness was summarized: (i) the gravels damage enhanced by cyclic loads makes them prone to fracture penetrating; (ii) cyclic compression weakens gravels and the cements holding them near the fracture, then the fracture surface deformation (shearing/slipping) is responsible to gravel detachment. In the end, the fracturing fluid friction affected by the fracture surface roughness was evaluated. This study is helpful for understanding and tailoring the fracturing design when the fracture surface roughness plays a critical role in the glutenite reservoir stimulation. • 3D-scanned fracture surface shows cyclic injection reduces surface roughness in glutenite fracturing. • Both cyclic tension, compression and shearing contribute to reduction in surface roughness. • Cyclic tension induced damage makes gravels prone to be penetrated near fracture tip. • Cyclic compression weakens the cements holding gravels along the fracture, responsible to gravel detachment. [ABSTRACT FROM AUTHOR]

A series of model tests was carried out for the clay ground improved by the fully or partly penetrated sand compaction pile (SCP) ground, in order to investigate the effect of the penetration ratio, the depth and the replacement area ratio of the SCPs. As the results, it was found that the stress concentration ratio varied with the depth and the penetration ratio of the SCPs. The stress concentration ratio decreased with an increase of the penetration ratio and strongly depended upon the process of consolidation and the replacement area ratio. [ABSTRACT FROM AUTHOR]

Intelligent Transportation Systems (ITSs) utilize Vehicular Ad-hoc Networks (VANETs) to collect, disseminate, and share data with the Traffic Management Center (TMC) and different actuators. Consequently, packet drop and delay in VANETs can significantly impact ITS performance. Feedback-based eco-routing (FB-ECO) is a promising ITS technology, which is expected to reduce vehicle fuel/energy consumption and pollutant emissions by routing drivers through the most environmentally friendly routes. To compute these routes, the FB-ECO utilizes VANET communication to update link costs in real-time, based on the experiences of other vehicles in the system. In this paper, we study the impact of vehicular communication on FB-ECO navigation performance in a large-scale real network with realistic calibrated traffic demand data. We conduct this study at different market penetration rates and different congestion levels. We start by conducting a sensitivity analysis of the market penetration rate on the FB-ECO system performance, and its network-wide impacts considering ideal communication. Subsequently, we study the impact of the communication network on system performance for different market penetration levels, considering the communication system. The results demonstrate that, for market penetration levels less than 30%, the eco-routing system performs adequately in both the ideal and realistic communication scenarios. It also shows that, for realistic communication, increasing the market penetration rate results in a network-wide degradation of the system performance. [ABSTRACT FROM AUTHOR]