Search Results (31)

Experimental investigations were conducted on the polyurea-coated steel plates experiencing localized air blast loads. The blast distance and polyurea coating position on the deformation and failure modes of the polyurea-coated steel plates were compared with those of homogeneous steel plates. The dynamic response failure and stress wave propagation characteristics of the polyurea-coated steel plates were studied. The results showed that under the localized air blast loads, the polyurea-coated steel plates demonstrated three failure modes: large flexural deformation, flexural deformation plus plugging breach, and flexural deformation plus plugging breach plus petal-like cracking. Under the same blast distance and surface density, the deformation and failure modes of the homogeneous steel plate were the same as those of the steel plate or polyurea-coated steel plate, but significantly different from those of the polyurea-coated steel plate. Coating polyurea on the non-blast-facing surface of steel plates exhibited better air blast resistance than coating polyurea on the blast-facing surface. Still, the air blast resistance of the polyurea-coated steel plate was insignificant compared to the homogeneous steel plates of the same weight. Full article

Purpose: The aim of this study was to evaluate the different approaches used in the treatment of meibomian gland dysfunction (MGD). Materials and Methods: This open-label, single-center, prospective pilot study with a parallel-group design was conducted in February 2025. Ninety-two patients presenting to our clinic with symptoms and signs of MGD were enrolled and diagnosed according to Japanese MGD diagnostic criteria. Patients were assigned to five treatment groups: conservative management alone, conservative management plus intense pulsed light (IPL) therapy, conservative management plus oral azithromycin, conservative management plus oral doxycycline, and conservative management plus topical cyclosporine. Conservative management consisted of preservative-free artificial tears containing polyvinyl alcohol and povidone, warm compresses, and eyelid hygiene. Primary outcome measures included ocular surface parameters such as the Ocular Surface Disease Index (OSDI), tear break-up time (TBUT), Standard Patient Evaluation of Eye Dryness (SPEED) scores, and meibomian gland parameters evaluated using a slit-lamp examination. All parameters were assessed at baseline and during follow-up examinations after treatment initiation to observe changes in symptoms and signs. Results: A statistically significant increase was determined in meibum grade plugging (grades 0–3; higher = greater obstruction) and Marx line scores with IPL therapy (p < 0.05). The group receiving doxycycline treatment exhibited a significant improvement in OSDI and SPEED scores, plugging, TBUT, and meibum grades. The group receiving cyclosporine registered a significant improvement in OSDI and SPEED scores, plugging, TBUT, and meibum grades. A statistically significant increase was observed in the conservative treatment group in terms of lid margin irregularity, Marx line score, and OSDI and SPEED scores. In the group receiving azithromycin treatment, plugging, lid margin irregularity, TBUT, and OSDI and SPEED scores increased significantly. Compared with conservative care, the doxycycline group exhibited lengthened TBUT and lowered meibomian gland plugging and symptoms (p < 0.05), and the oral azithromycin group achieved a similar TBUT gain with slightly greater symptom relief. The topical cyclosporine group principally registered improved lid vascularity and meibum quality (p < 0.05), while the IPL group achieved the greatest overall improvements, reducing plugging and Marx line scores and adding ≈3 s to TBUT (p < 0.05 for all endpoints). Doxycycline exhibited notable short-term improvements, with 35.26% meibum grade improvement and a 40.48% foaming response, while IPL therapy demonstrated substantial OSDI improvements at 54.06%, with traditional parameters indicating limited treatment responsiveness. Conclusions: Various methods can be used in the treatment of MGD. All the conservative treatment methods used in this study were successful. Full article

This study examines the spatial root development patterns of bareroot, containerized, and plug plus (plug+) saplings in hemiboreal forests of Latvia, focusing on the effects of two common soil preparation methods: mounding and disc trenching. In northern Europe, forest regeneration after clearcutting often involves planting, with soil preparation aimed at enhancing sapling survival and productivity. This study included four tree species: Pinus sylvestris, Picea abies, Betula pendula, and Alnus glutinosa. The results reveal that saplings planted in mounded sites developed more radially symmetrical root systems, while roots in trenched sites predominantly grew parallel to the furrow. This spatial root distribution was consistent across all forest types and did not show significant variation between stock types (containerized, bareroot, or plug+) or treatments (control or fertilized). Additionally, the number of main roots did not differ significantly between the soil preparation methods. These findings align with previous research and raise important questions regarding the impact of early root architecture on stand resilience at a mature stage, particularly in relation to windthrow, heavy snowfall, drought, and flooding resistance. The study underscores the need to consider root system development as a key factor in forest management practices aimed at ensuring long-term forest stability. Full article

Improvement of recreational areas between the residential areas to achieve human behavior and the concept of humanization is urgently needed to achieve the 2030 vision of Saudi Arabia. This study aims to develop a parametric urban optimization framework to optimize the outdoor thermal comfort in outdoor recreational areas between residential buildings in Riyadh City, Saudi Arabia, based on the 2030 vision of Saudi Arabia to achieve a high standard of quality of life with thermal comfort. Measurement was conducted inside the sports walking path with walk-through observation and interviews. Then, case study geometry was generated computationally, using Rhinoceros software and its plug-in Grasshopper to implement the set of development scenarios. Then, the optimization process for the case study was integrated with 192 proposed development solutions to assess the solutions’ influence in reducing the Universal Thermal Comfort Index (UTCI) and average solar irradiance, besides increasing energy generated by PV panels. EnergyPlus engine and Ladybug plug-in are used to integrate PV panels with shading scenarios, to utilize the high solar irradiation, and to calculate the generated electrical energy. The results concluded that trees with diameters between 10 and 15 m could achieve thermal comfort and reduction UTCI by 11.26 K and average solar irradiance by 642.77 W/m² with average energy generation of PV panel and optimum inclination angle of 20°. The integration of PV with shading scenarios generates electricity for every square meter of PV panel, equal to 578.84 kWh/m² for lighting poles and service areas within the recreational areas. The results of this study help to improve the current park as a prototype, for which results can be implemented in more than 8100 instances of gardens, parks, and municipal squares in Saudi Arabia. Full article

Background/Objectives: Microvascular plug embolization in the distal feeding artery (FA-MVP) and coil embolization targeting the nidus and feeding artery (NiFA-coil) are effective treatments for pulmonary arteriovenous malformations (PAVMs). This study compares their outcomes. Methods: A retrospective chart review was conducted on patients who underwent NiFA-coil or FA-MVP embolization for PAVMs between October 2014 and May 2024, with initial (short-term) follow-up chest CT imaging performed within 18 months, and the latest (long-term) follow-up performed at least 3 years post-treatment. Durable occlusion was defined as ≥70% shrinkage of the nidus or draining vein on follow-up CT. A Cox proportional hazards regression model assessed the association between technique and durable occlusion, with inverse propensity score weighting used to adjust for patient and PAVM characteristics. Results: A total of 142 PAVMs (48 FA-MVP, 94 NiFA-coil) in 85 patients were analyzed. Durable occlusion was 97.2% (138/142) at a median short-term follow-up of 4.2 months and 90.2% (37/41) at a median long-term follow-up of 56.0 months. Simple PAVMs were more frequent in the FA-MVP group (93.8%, 45/48) than in the NiFA-coil group (61.2%, 58/94) (p < 0.001). The NiFA-coil group had larger feeding arteries (3.8 mm vs. 2.3 mm, p < 0.001) and sac sizes (13.1 mm vs. 7.7 mm, p = 0.040). Short and long-term durable occlusion rates were comparable (NiFA-coil: 96.8% and 88.9%; FA-MVP: 97.8% and 92.9%, respectively; p > 0.99, p > 0.99). After propensity score matching, compared to FA-MVP, NiFA-coil had a hazard ratio for short-term persistence of 1.06 (95% CI, 0.16–6.99; p = 0.956). Conclusions: Both NiFA-coil and FA-MVP embolization are highly effective for PAVM treatment, with similar success rates. Full article

This study explores the relation between catalyst research and chemical reaction engineering for developing ethanol to butadiene (ETB) technologies. An ETB process involves two distinct steps: ethanol dehydrogenation to acetaldehyde and butadiene synthesis. The catalyst functions can be tailored separately or imbedded in a single formulation, leading to two-stage and one-stage processes. The performance of selected ETB catalysts is confronted with predictions based on chemical equilibrium, considering the simultaneous formation of products, by-products and impurities. The analysis shows that, essentially, the performance of ETB catalysts is controlled by kinetic factors. A shortlist of relevant catalysts for industrial implementation is proposed. The analysis highlights two key issues for industrial reactor design: catalyst deactivation/regeneration and the use of inert gas as a major process cost. The first issue is addressed by developing a comprehensive fluidized bed reactor model operating in the bubbling regime, capable of handling complex reaction kinetics. Good performance close to plug flow is obtained with bubbles at a size of 4 to 8 cm and with intensive mass transfer. The simulation reveals an autocatalytic effect of acetaldehyde on the butadiene formation favored by a well-mixed dense phase. The second study investigates the optimization of the chemical reaction section in a reactor–separation–recycle system via economic potential. The costs associated with the catalytic reactor and the catalyst charge, including regeneration, along with the costs of recycling reactants and of an inert gas if used, are key factors in determining the optimal operation region. This approach, verified by simulation in Aspen Plus^TM, points out that better robustness and a limited use of an inert gas are necessary for developing industrial catalysts for the one-stage ETB process. Full article

In modern agriculture today, the cultivation of agricultural products cannot be imagined without greenhouses. This paper presents an energy optimization of a solar greenhouse with a photovoltaic system (PV) and a ground-source heat pump (GSHP). The PV system generates electricity, while the GSHP is used for heating and cooling. A greenhouse is designed with an Open Studio plug-in in the Google SketchUp environment, the EnergyPlus software (8.7.1 version) was used for energy simulation, and the GenOpt software (2.0.0 version) was used for optimization of the azimuth angle and PV cell efficiency. Results for different solar greenhouse orientations and different photovoltaic module efficiency are presented in the paper. The obtained optimal azimuth angle of the solar greenhouse was −8°. With the installation of a PV array with higher module efficiency (20–24%), it is possible to achieve annual energy savings of 6.87–101.77%. Also, with the PV module efficiency of 23.94%, a concept of zero-net-energy solar greenhouses (ZNEG) is achieved at optimal azimuth and slope angle. Through the environmental analysis of different greenhouses, CO₂ emissions of PV and GSHP are calculated and compared with electricity usage. Saved CO₂ emission for a zero-net-energy greenhouse is 6626 kg CO₂/year. An economic analysis of installed renewable energy systems was carried out: with the total investment of 19,326 € for ZNEG, the payback period is 8.63 years. Full article

The shallow, thin super-heavy oil reservoir demonstrates certain characteristics, such as shallow reservoir depths, low-formation temperature, and high crude oil viscosity at reservoir temperatures. In the current production process, the central area of P601 is undergoing high-frequency huff and puff operations, facing certain problems such as decreasing production, low recovery rates, and rapid depletion of formation pressure. Through physical simulation experiments, the various elements of HDNS-enhanced oil recovery technology were analyzed. Nitrogen plus an oil-soluble viscosity reducer can improve the thermal recovery and development effect of super-heavy oil. With the addition of the viscosity-reducing slug, the recovery rate of steam flooding was 58.61%, which was 23.32% higher than that of pure steam flooding; after adding the 0.8 PV nitrogen slug, the recovery rate increased to 76.48%. With the increased nitrogen injection dosage, the water breakthrough time was extended, the water cut decreased, and the recovery rate increased. Nitrogen also plays a role in profile control and plugging within the reservoir; this function can effectively increase the heating range, increase steam sweep efficiency, and reduce water cut. So, the synergistic effects of steam, nitrogen, and viscosity-reducing agents are good. This technology enhances the development of shallow-layer heavy oil reservoirs, and subsequent development technologies are being compared and studied to ensure the sustainable development of super-heavy oil reservoirs. Full article

This simulation study explores the potential of a novel façade design with integrated control system comprising a dynamic photovoltaic (PV) facade integrated with dimming lighting control to enhance the work environment in office buildings and achieve energy-efficient solutions. Parametric modeling using the Grasshopper plug-in for Rhino software 7, coupled with energy simulation through the Honeybee environmental plug-in for the EnergyPlus program, are used in the methodology. The integrated control strategy was simulated to study in a single office space, utilizing the Daysim engine to assess indoor daylight quality and focusing on Daylight Factor (DF) and Daylight Glare Probability (DGP). Additionally, two artificial lighting control systems were examined for potential integration with the dynamic PV facade to minimize lighting load. The study employs the Galapagos evolutionary solver function embedded within Grasshopper to identify optimum solutions. The dynamic PV façade achieves substantial reductions in overall energy consumption, cutting it by 73% in June, 54% in July, 54.5% in August, and 52.55% in September. The results demonstrate substantial reductions in total energy consumption, with notable savings in heating and cooling due to the dynamic facade’s ability to balance and control solar radiation during working hours. Moreover, the dynamic PV facade contributes to electricity generation, demonstrating its potential to improve visual comfort, decrease energy consumption, and generate electric energy through rotational adjustments and varying transparency levels. Full article

In this study, a comparative study was conducted on the two reactor types (the plug-flow and continuous stirred tank reactor) employed for the traditional esterification process to investigate their potential applications to the esterification reaction with the ethanol-rich feed. Aspen Plus software was used to conduct a sensitivity analysis on the temperature profiles in the axial and radial directions, focusing in particular on the reactor and feed stream temperatures, operating parameters, and ethyl acetate yields for the reactors. The energy analysis for esterification processes with the different reactor types has also been evaluated. Compared with the continuous stirred tank reactor, the plug-flow reactor process with the ethanol-rich feed exhibited reduced hotspot temperatures. The simulation results show that the hotspot temperatures in the continuous stirred tank reactor can be within the operating temperature range of 90–100 °C. Regarding the comparison of these reactor types for the esterification process, the plug-flow reactor shows advantages in terms of efficient hotspot temperature with the operating temperature range of 70–75 °C. On the other hand, the yield of ethyl acetate product from the continuous stirred tank reactor is slightly higher than from the alternative esterification process with excess ethanol feed. Full article

Bowman’s layer is an acellular layer in the anterior stroma found in the corneas of humans, most other primates, chickens, and some other species. Many other species, however, including the rabbit, dog, wolf, cat, tiger, and lion, do not have a Bowman’s layer. Millions of humans who have had photorefractive keratectomy over the past thirty plus years have had Bowman’s layer removed by excimer laser ablation over their central cornea without apparent sequelae. A prior study showed that Bowman’s layer does not contribute significantly to mechanical stability within the cornea. Bowman’s layer does not have a barrier function, as many cytokines and growth factors, as well as other molecules, such as EBM component perlecan, pass bidirectionally through Bowman’s layer in normal corneal functions, and during the response to epithelial scrape injury. We hypothesized that Bowman’s layer represents a visible indicator of ongoing cytokine and growth factor-mediated interactions that occur between corneal epithelial cells (and corneal endothelial cells) and stromal keratocytes that maintain the normal corneal tissue organization via negative chemotactic and apoptotic effects of modulators produced by the epithelium on stromal keratocytes. Interleukin-1 alpha, produced constitutively by corneal epithelial cells and endothelial cells, is thought to be one of these cytokines. Bowman’s layer is destroyed in corneas with advanced Fuchs’ dystrophy or pseudophakic bullous keratopathy when the epithelium becomes edematous and dysfunctional, and fibrovascular tissue commonly develops beneath and/or within the epithelium in these corneas. Bowman’s-like layers have been noted to develop surrounding epithelial plugs within the stromal incisions years after radial keratotomy. Although there are species-related differences in corneal wound healing, and even between strains within a species, these differences are not related to the presence or absence of Bowman’s layer. Full article

The Y oilfield reservoir is characterized by ultra-depleted reservoir and multiple pressure systems in each well section. If conventional PLUS/KCL drilling fluid is used in directional drilling, the following problems are found: the rheological stability of drilling fluid is not sufficient, resulting in increased viscosity and thickening after aging, and the single plugging material may cause loss-circulation when the drilling differential pressure is more than 26 MPa, resulting in poor reservoir protection effects. To solve the above problems, based on the conventional PLUS/KCL drilling fluid formula, a PLUS/KCL drilling fluid system suitable for directional drilling in multi-pressure systems was formed by optimizing the addition of a treating agent to improve the rheological stability of the drilling fluid, optimizing the plugging agent and compound combination to improve plugging ability, and optimizing the particle size distribution of a temporary plugging agent to improve the reservoir protection effect. The laboratory test evaluation showed that the optimized PLUS/KCL drilling fluid had fine plugging pressure capacity, and the intrusion depth was only 4.1 cm on the natural core at 120 °C/35 MPa/12 h, effectively reducing the risk of loss-circulation. The permeability recovery rate of the core after cutting off the polluted end was more than 90%, indicating that the reservoir protection effect was good. The drilling fluid performance was stable, and the cuttings rolling recovery rate was over 90%. Field application showed that the optimized PLUS/KCL drilling fluid was used without any loss-circulation or wellbore instability, and the production of all wells was over-matched, effectively solving the problem of ensuring drilling safety and reducing reservoir damage under the differential pressure of multiple pressure systems. Full article

This paper represents a detailed techno-economic analysis of a typical commercial-scale catalytic decarboxylation process of naphthenic acids over HZSM-5 zeolite. Simulation of the process has been performed in ASPEN Plus^®. The performance of the modeled unit was compared to experimental results data from a similar plant. Two models were developed for the proposed industrial plant based on continuous flow reactors; the first is based on a fluidized bed reactor, and it was modeled as a continuous stirred tank reactor (CSTR) unit, and the second is a semi-regenerative process that consists of three fixed-bed reactors with intermediate preheaters and are modeled as three plug flow reactors (PFR). The outcome of the economic analysis of the two proposed commercial scale reactors of a decarboxylation process of a capacity of 11,000 bbl/day showed that the CAPEX, including the total equipment cost for the fluidized bed reactor plant and semi-regenerative process plant, was $44,319,362 and $4,447,919, respectively. The annual operating cost for the fluidized bed plant and semi-regenerative process plant is 45,269,180 $/year and 1,771,839 $/year, respectively. Our results demonstrated that catalytic decarboxylation over HZSM-5 zeolite is economically feasible using a semi-regenerative process, and is a promising method for removing naphthenic acid. The insight obtained from this work can be used as a basis for more comprehensive future financial and risk modeling of the process. The cost estimated in this work was compared to the Khartoum refinery cost for the naphthenic acid corrosion mitigation system, with a saving of $29,459,528. Full article

Blepharospasm patients often have dry eye manifestations. Botulinum neurotoxin type A (BoNT-A) injection has been the main management for blepharospasm and absorbable punctal plug (APP) insertion is shown to be effective in the treatment of dry eye. However, there have been no studies investigating the combined treatment of BoNT-A and APP in blepharospasm patients with dry eye. In this retrospective study, 17 blepharospasm patients with dry eye treated by BoNT-A injection and 12 receiving BoNT-A plus APP treatment were enrolled. The efficacy was evaluated according to the Jankovic rating scale, Ocular Surface Disease Index (OSDI), fluorescein staining (FL), fluorescein tear break-up time (FBUT) and Schirmer I test (SIT). Both BoNT-A and BoNT-A+APP treatment effectively reduced the functional impairment of blepharospasm. At baseline, all the patients had high OSDI scores (BoNT-A group: 82.48 ± 7.37, BoNT-A+APP group: 78.82 ± 4.60, p = 0.112), but relatively low degrees of FL (BoNT-A group: 3.18 ± 1.01, BoNT-A+APP group: 3.50 ± 1.24, p = 0.466), FBUT (BoNT-A group: 1.71 ± 0.77, BoNT-A+APP group: 2.17 ± 0.58, p = 0.077) and SIT (BoNT-A group: 2.53 ± 0.99, BoNT-A+APP group: 3.17 ± 1.23, p = 0.153). After treatment, OSDI, FL, FBUT and SIT were all obviously restored in the two groups. When comparing the changing rates, only OSDI (BoNT-A group: −52.23% ± 15.57%, BoNT-A+APP group: −61.84% ± 9.10%, p = 0.047) and FL (BoNT-A group: −22.55% ± 25.98%, BoNT-A+APP group: −41.94% ± 14.46%, p = 0.016) showed significant differences between the two groups. This study suggests that OSDI is not applicable in the diagnosis of dry eye among blepharospasm patients. For blepharospasm patients with severe dry eye symptoms, especially those with fluorescein staining in the cornea, the combined treatment of BoNT-A and APP is more effective than using BoNT-A alone. Full article

The gas reservoirs in the Northwestern Sichuan Basin have great development potential. However, their production efficiency is seriously reduced by the complex surface multistage throttling process and frequent hydrate plugging caused by the ultra-high-pressure sour gas. Considering the prevention and control of hydrates, properly designing the throttling temperature and pressure to optimize the surface production process is the key to solving this problem. First, this work presents a method for predicting the hydrate formation conditions of ultra-high-pressure sour natural gas based on the vdW-P (van der Waals–Platteeuw) model and the CPA (cubic-plus-association) equation of state (EoS) and considering the association between acid gases (H₂S, CO₂) and H₂O. Secondly, the throttling temperature prediction method was developed by coupling the isenthalpic throttling model and the modified Lee–Kesler EoS mixing rule; the maximum throttling pressure difference calculation method was constructed based on the critical flow principle. Finally, field cases are given to illustrate the distribution process of assigning the maximum throttling pressure differences. The results show that the proposed model can accurately predict the hydrate formation conditions and throttling temperature of ultra-high-pressure sour natural gas, and reveal their changing laws. The surface throttling technology of the ultra-high-pressure sour gas wells Long 004-X1 and Long 016-H1 was optimized from five-stage to three-stage, and the application of the fixed throttle valve in the field is successfully demonstrated. Full article