Optimal Diameter Research Articles

Inversion of magnetic diameter distribution of magnetic fluids under high and low temperatures

The magnetic diameter is a crucial factor affecting the magnetic properties of magnetic fluids. The magnetic diameter distribution can be estimated based on the magnetic properties. However, the magnetic dipole interaction of magnetic nanoparticles (MNPs) and the variation of the magnetic diameter with temperature have received relatively little attention in previous research. Hence, this research proposes the AP-MMF1-L method to inverse the magnetic diameter which considers the magnetic dipole interaction and derives the magnetic diameter at different temperatures. Firstly, the AP-MMF1-L uses the least square method between the first-order modified mean-field Langevin function (MMF1-L) and the measured magnetization curve as the objective function. Meanwhile, the hybrid Artificial bee colony-particle swarm (AP) optimization algorithm is introduced to inverse the optimal magnetic diameter distribution. Secondly, the hydrodynamic diameter distribution experimental values are compared with the theoretical values, demonstrating the AP-MMF1-L method obtains accurate inversion results of the magnetic diameter distribution when compared to other models. Finally, the arithmetic mean of the magnetic diameter at different temperatures is investigated, revealing a decreasing trend as the temperature rises, approximately following a linear distribution. The AP-MMF1-L provides a novel and effective tool for accurately determining the magnetic diameter of the MNPs across various temperatures.

Detection of Cysteine Using Graphene Quantum Dots/Titanium Dioxide Nanotube-Based Biosensor

The objective of this research was to analyze the diagnostic value of a graphene quantum dots (GQDs)-titanium dioxide (TiO2) nanotube-based biosensor for L-cysteine (Cys). TiO2 nanotubes were prepared using anodic oxidation, GQDs were synthesized using thermal decomposition of citric acid, and TiO2-GQDs composite materials were fabricated using electrophoresis. A biosensor based on TiO2-GQDs was constructed, and the stability and photocatalytic efficiency of the TiO2-GQDs material were analyzed using X-ray diffraction (XRD) and a dual-beam ultraviolet-visible spectrophotometer (UVS). Cys detection was performed using the TiO2-GQDs biosensor, and the sensitivity, pH, time response, and selectivity of TiO2-GQDs towards Cys were analyzed using a fluorescence spectrophotometer (FS). The results revealed that TiO2 nanotubes with optimal diameter and length were obtained at an oxidation voltage of 80 V and oxidation time of 2 hours, with a greatly increased specific surface area (SSA) compared to those at 40 V and 50 V (P <0.05). Under constant oxidation voltage, longer oxidation time resulted in longer nanotube length. The microstructure of GQDs was clear, and the diffraction peaks and photocatalytic efficiency of GQDs in TiO2-GQDs increased with increasing GQDs content. The fluorescence quenching intensity (FQI) of TiO2-GQDs solution increased with increasing Cys concentration. After the addition of Cys, the FQI of TiO2-GQDs solution was much higher than that of 19 other amino acids (AAs) (P <0.05). However, difference in the F0−F value between Cys and interference AAs in TiO2-GQDs solution was not great (P >0.05). In conclusion, TiO2-GQDs material exhibited good stability and photocatalytic efficiency. The biosensor based on TiO2-GQDs demonstrated high sensitivity and selectivity towards high-concentration Cys solutions, showing promising applications in biomedicine.

Nanocrystal Agglomerates of Curcumin Prepared by Electrospray Drying as an Excipient-Free Dry Powder for Inhalation.

Curcumin has shown beneficial effects on pulmonary diseases with chronic inflammation or abnormal inflammatory responses, including chronic obstructive pulmonary disease, asthma, and pulmonary fibrosis. Clinical applications of curcumin are limited due to its chemical instability in solution, low water solubility, poor oral bioavailability, and intestinal and liver first-pass metabolism. Pulmonary delivery of curcumin can address these challenges and provide a high concentration in lung tissues. The purpose of the current work was to prepare a novel inhalable dry powder of curcumin nanocrystals without added excipients using electrospray drying (ED) with improved dissolution and aerosolization properties. ED of curcumin was performed at 2 and 4% w/v concentrations in acetone. Physicochemical properties of the formulated powders were evaluated by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), density and powder flow measurements, and in vitro dissolution. The in vitro deposition studies were conducted using next-generation impactor (NGI) and aerosol performance and aerodynamic particle size parameters were calculated for prepared formulations. ED could produce agglomerates of nanocrystals with a size of about 500 nm at an acceptable yield of about 50%. PXRD and FTIR data revealed that prepared nanocrystals were in a stable crystalline state. The bulk and tapped density of prepared agglomerates were in the range appropriate for pulmonary delivery. Formed nanocrystals could significantly improve the dissolution rate of water-insoluble curcumin. The optimized formulation exhibited acceptable recovered dose percentage, high emitted dose percentage, optimum mean mass median aerodynamic diameter, small geometric standard deviation, and high fine-particle fraction that favors delivery of curcumin to the deep lung regions. The ED proved to be an efficient technique to prepare curcumin nanocrystals for pulmonary delivery in a single step, at a mild condition, and with no surfactant.

Numerical simulation of mixing effect of compressed air–foam gas–liquid mixer

This article investigated the effect of geometric structural parameters on flow patterns and pressure drops and gas–liquid mixing effects of gas–liquid mixing devices. The computational fluid dynamics software FLUENT was used to calculate the airflow inside the mixer of a compressed air–foam gas–liquid mixing device with different cone angles, foam flow rates, air inlet inclination angles, and pipeline diameters. The results obtained are the pressure distribution, the liquid volume fraction, and the liquid phase streamlines in the mixing device. The numerical simulation results showed that for a gas–liquid mixing device, the optimal inlet inclination angle was 60°–70°, and the mixing effect of an equal diameter mixer was better than that of a variable diameter mixer, but it would reduce the mixing efficiency of the air and foam. The optimal pipeline diameter of the conveying pipeline was 190 mm, and the optimal cone angle of the mixing device was 55°.

Selection of Interferential Screw for Fixation of Graft in Tibial Tunnel during Anterior Cruciate Ligament Reconstruction by Novel Probe Test.

Anterior cruciate ligament (ACL) reconstruction is a common orthopedic procedure, employing various grafts such as the hamstring tendon, bone-patellar bone, and quadriceps tendon. Fixation methods include suspensory loop with button, interferential screw, and cortical fixation. The optimal screw diameter for tibial tunnel fixation remains undefined, with choices ranging from 1mm smaller to 1-2 mm larger than the tunnel diameter. Screw-related complications such as breakage and thread flattening are concerns. This study was to determine the ideal screw diameter for secure graft fixation in the tibial tunnel during ACL reconstruction. A novel arthroscopic probe technique was utilized to assess tibial tunnel bone integrity. Bone quality was categorized into weak, strong, and very strong. Screw size selection, either equal to or 1-2 mm larger than the tunnel diameter, was based on bone quality. Screw lengths varied from 25 mm to 35 mm. The novel technique significantly reduced screw-related complications, from 9.6% (24 out of 248 patients) to 0.5% (l out of 187 patients). The need for additional cortical stabilization decreased from 14.5% (36 out of248 patients) to 1.6% (3 out of 187 patients). The low-cost, efficient 2-min probe test is a secure and effective method for selecting interferential screws in ACL reconstruction, minimizing complications, and additional stabilization needs.

The effect of pump diameter and penstock pipe on the electric power of a hybrid generator

Ocean Wave Power Plants (WEC) are divided into 6 types, namely (1) Point Absorber, (2) Oscillating Water Column, (3) Pressure Differential Submerger, (4) Oscillating Wave Surge Converter, (5) Attenuator & Terminator, and ( 6) Removable Devices. The AquabuOY type is a type of Point Absorber type wave power generator. This type uses a long pump connected to a Pelton turbine and was developed by Finavera (Aquaenergy) Company of Canada. The AquabuOY system has a weakness in that the turbine rotation depends on the wave period that occurs. The slower the wave period occurs, the weaker the resulting turbine rotation, therefore it needs to be improved by adding a reservoir unit to obtain pressure. stability and puffiness of the unit so that the rotation produced in the turbine is much greater. With this addition, the generator will spin more quickly and stably. In addition, the addition of wind energy installed at the top of the unit means that the generator to be built will produce more energy, is more flexible, can be placed in shallow, medium or deep seas, does not require complicated foundations, is relatively cheap, is not affected by extreme weather. and can be used in all sea conditions just by attaching it to a ballast. This study examines the effect of pump diameter and outlet pipe diameter on the electrical power generated at a hybrid power plant. pump diameter variations of 8 inches, 10 inches, 12 inches and 14 inches. Variation of outlet pipe diameter 1 inch, 2 inch, 3 inch and 4 inch. In this paper, we will present a simulation of the calculation of electrical energy from wave power with variations in pontoon volume, pump diameter, and outlet pipe diameter to obtain the most optimal system size. while wind energy power generation is presented in a different pape. Calculation simulation results to get the most optimal pump diameter and outlet pipe diameter in the hybrid power plant system built.

Resonant Raman scattering on graphene: SERS and gap-mode TERS.

Nanoscale deformations and corrugations occur in graphene-like two-dimensional materials during their incorporation into hybrid structures and real devices, such as sensors based on surface-enhanced Raman scattering (SERS-based sensors). The structural features mentioned above are known to affect the electronic properties of graphene, thus highly sensitive and high-resolution techniques are required to reveal and characterize arising local defects, mechanical deformations, and phase transformations. In this study, we demonstrate that gap-mode tip-enhanced Raman Scattering (gm-TERS), which offers the benefits of structural and chemical analytical methods, allows variations in the structure and mechanical state of a two-dimensional material to be probed with nanoscale spatial resolution. In this work, we demonstrate locally enhanced gm-TERS on a monolayer graphene film placed on a plasmonic substrate with specific diameter gold nanodisks. SERS measurements are employed to determine the optimal disk diameter and excitation wavelength for further realization of gm-TERS. A significant local plasmonic enhancement of the main vibrational modes in graphene by a factor of 100 and a high spatial resolution of 10 nm are achieved in the gm-TERS experiment, making gm-TERS chemical mapping possible. By analyzing the gm-TERS spectra of the graphene film in the local area of a nanodisk, the local tensile mechanical strain in graphene was detected, resulting in a split of the G mode into two components, G+ and G-. Using the frequency split in the positions of G+ and G- modes in the TERS spectra, the stress was estimated to be up to 1.5%. The results demonstrate that gap-mode TERS mapping allows rapid and precise characterization of local structural defects in two-dimensional materials on the nanoscale.

Effect of mixing chamber structure on the performance of adjustable ejector

The study employs numerical simulation method to analyze performance of an adjustable ejector, with a specific focus on the influence of the structure dimension of mixing chamber. R41/R1234yf refrigerant is used as the working medium in the study. The primary and secondary flow inlets are set at the pressure of 1.4 MPa and 0.2 MPa, respectively, along with temperature of 353.15 K and 288.15 K corresponding. The outlet pressure of the ejector is 0.3 MPa. The simulation results show that optimal mixing chamber diameter within a range from 14.7mm to 18.7mm exists for obtaining peak adjustable ejector performance. Maximum entrainment ratio of 0.59 is obtained when cone diameter ratio is 65% and diameter of the mixing chamber is 15.7mm. Furthermore, the optimal mixing chamber length within range from 24mm to 220mm exists for obtaining peak adjustable ejector performance. Maximum entrainment ratio of 0.624 is obtained when cone diameter ratio is 76% and length of the mixing chamber is 88 mm. Therefore, it is crucial during designing process of the mixing chamber to ensure the complete fluid mixture and minimal flow resistance.

Comparison of Screws with Different Diameters in Subperiosteal Implant Application with Finite Element Analysis.

Purpose: This study aimed to assess subperiosteal implants concerning bone stress and screw displacement, utilizing finite element analysis to determine the optimal screw diameter for enhanced bone support. Methods: Computed tomography data were translated into STL format, generating two skull models. Subperiosteal implants were constructed on these models and placed accordingly. Employing the finite element analysis method, screws with 1.5 mm and 2 mm diameter were inserted into one of the models to evaluate their impact under a 250 N chewing force. Results: The 2 mm screw demonstrated superior performance compared to the 1.5 mm variant, showcasing reduced residual stress on the bone and implant. However, the 1.5 mm screw exhibited less implant movement. Conclusion: The finite element analysis suggests the 2 mm screw diameter as more advantageous over the 1.5 mm variant for subperiosteal implants. Nevertheless, this investigation marks the initial stages in exploring this treatment option's potential.

Experimental and numerical investigation on the impact of MS2AF on local scour protection performance

Suction anchor foundations are widely used in the offshore wind power industry. The installation of suction caissons alters the near-bed flow field and leads to local scour. This study proposes a novel integrated design for the scour protection of suction anchor foundations, known as the multihole sector suction anchor foundation (MS2AF). Through indoor flume experiments and numerical flume simulations, the local scour protection performances of MS2AFs with different design parameters under the action of steady flow were investigated. The results showed that the scour evolution of MS2AFs can be divided into three stages: slow scour, rapid scour, and scour equilibrium. The MS2AF reduced the flow shear stress on the sediment bed, thereby decreasing the depth and range of the local scour. The maximum scour depth, width, and length of the scour hole exhibited negative linear relationships with the width and thickness of the sector and decreasing-then-increasing relationships with the diameter and area ratio of the holes. Among these factors, the sector's thickness had the most significant impact. There existed an optimal diameter and area ratio that maximized the stratification effect and deceleration effect of the multihole sector.

Artificial intelligence assisted preoperative planning and 3D-printing guiding frame for percutaneous screw reconstruction in periacetabular metastatic cancer patients.

The percutaneous screw reconstruction technique, known as the "Tripod Technique," has demonstrated favorable clinical outcomes in the management of metastatic periacetabular lesions, as evidenced by our prior investigations and corroborated by independent studies. Nevertheless, there is a steep learning curve in handling this technique, with possible complications such as intraarticular screw placement. Preoperative pelvic CT scans were acquired before surgery and utilized for the guiding frame design. A convolutional neural network model was trained with annotated data to identify the starting point and trajectory of each potential screw. A model boundary intersection detection technology was used to determine the optimal diameter and length of each screw. A non-rigid registration technology was matched with a prefabricated model of the body surface to design personalized anchoring skin pads. Finally, a polylactic acid-based guiding frame for intraoperative was custom-made with a 3D printer. 12 patients underwent a guiding frame-assisted Tripod procedure for treatment of periacetabular metastatic lesions. An intraoperative CT scan was performed in all cases to confirm screw trajectories. Among 36 screws that were implanted, 26 screws were implanted as designed. The remaining ten screws drifted, but all remained within the intra-osseous conduit without any complications. The mean surgical time was 1.22h with the guiding frame compared with 2.3h without the guiding frame. Following the surgical procedure, a noteworthy enhancement in pain management, as evidenced by a reduction in scores on the visual analog scale (p < 0.01), and an improvement in functional status, as assessed through the Eastern Cooperative Oncology Group score (p < 0.01), were observed when compared to the patient's pre-operative condition. This proof-of-concept investigation demonstrates that the amalgamation of AI-assisted surgical planning and additive manufacturing can improve surgical accuracy and shorten surgical duration. While access to this technology is currently constrained during its early stages of development, it is anticipated that these limitations will diminish as the potential of AI and additive manufacturing in facilitating complex orthopedic procedures becomes more evident, leading to a surge in interest and adoption of this approach.

Simulation and analysis of hydraulic transition process based on mechanical hydraulics.

With the scarcity of water resources in various regions, the pressure on water supply projects is also increasing, which has led to a sharp increase in the water hammer effect in water supply pump projects. In response to this issue, the study proposes to apply a unidirectional pressure regulating tower based on mechanical hydraulic technology to water hammer protection in water supply pumps. In addition, the study also optimizes the calculation method of water hammer and designs one simulation software, which is used to simulate and analyze the proposed water hammer protection measures. The study first determines through simulation software that the optimal initial water level of the unidirectional pressure regulating tower is 2m and the optimal diameter of the make-up water pipe is 600 mm. Afterwards, simulation analysis is conducted on different water hammer protection measures, and it is found that the maximum pressure of the water hammer under the proposed protection measures is the lowest, at 14.8m, which was lower than the comparison measures. In addition, according to expert ratings, the average protective effect rating of protective measure 1 by relevant technical personnel is 9.4 points, which is better than the comparative measure. The above results indicate that through the simulation analysis of hydraulic transition process based on mechanical hydraulics, it can be found that the water hammer protection measures proposed in the study have good protective functions and can effectively reduce the water hammer effect in water supply engineering.

Perovskite-Type Oxynitride Nanofibers Performing Photocatalytic Oxygen and Hydrogen Generation

(111)-layered perovskites such as Ba5Ta4O15 or Ba5Nb4O15 are known for their promising activity in hydrogen evolution and overall water splitting.[1] Their activity can be further enhanced by the preparation of Ba5Ta4O15-Ba3Ta5O15-BaTa2O6 composites.[2,3] However these materials can only absorb UV-light, which prevents them to be used in solar-light induced photocatalysis. Therefore, the preparation of visible-light absorbing photocatalysts is very important for future application in solar-light induced hydrogen evolution and overall water splitting.Perovskite-type oxynitrides AB(O,N)3 are one group of materials which can absorb visible light, i.e. BaNbO2N with an absorption edge up to 740 nm.[4-7] These perovskite-type oxynitrides can be quite easily prepared by ammonolysis of (111)-layered perovskites, due to their structural similarity of 6-fold coordinated B cations, corner-shared BO6 octahedra, and the 12-fold oxygen coordinated A cations in both crystal structures.[8] However, this conversion often results in micrometer-sized particles due to the high temperatures used in the ammonolysis process, thus resulting in small surface areas.[6,7] Therefore, the nanostructuring of such perovskite-type oxynitrides can be of interest, due to the higher surface area and shorter diffusion pathways of the minority charge carriers. One possibility to nanostructure photocatalysts and enhance the photocatalytic activity is the electrospinning of nanofibers. Hildebrandt et al. and Bloesser et al. reported the preparation of highly crystalline Ba5Nb4O15, Ba5Ta4O15, and Ba5Nb2Ta2O15 (111)-layered perovskite nanofibers and the tailoring of the nanofiber diameter of Ba5Ta4O15 and Ba5Ta4O15-Ba3Ta5O15 nanofibers by electrospinning.[9-11]Herein, we present a novel approach for the preparation of nanostructured complex perovskite oxynitrides.[12] Ba5Nb4O15 (111)-layered perovskite nanofibers with tailored nanofiber diameters were electrospun and converted via ammonolysis. Most importantly, the nanofiber morphology was maintained during ammonolysis, and the nanofiber diameter could be adjusted as well. A thorough characterization, including Rietveld refinement, revealed the formation of a novel BaNbO2N-Ba2NbO3N perovskite oxynitride composite. UV-vis measurements further supported the results of a BaNbO2N-Ba2NbO3N composite formation and revealed a reduction of the band edge by more than 2 eV from 3.9 eV for Ba5Nb4O15 to 1.7 eV for the converted nanofiber composites. A diameter-dependent hydrogen and oxygen evolution activity of the BaNbO2N-Ba2NbO3N composite nanofibers after deposition of Pt or CoNbO4, respectively, with an optimum nanofiber diameter will be presented.[1] Y. Miseki et al. Energy Environ. Sci. 2019, 2, 306 [2] J. Soldat, et al. Chem. Sci. 2014, 5, 3746[3] A. Hofmann et al. J. Phys. Energy 2021, 3, 014002[4] T. Hisatomi et al., Energy Environ. Sci., 2013, 6, 3595[5] J. Seo et al., J. Mater. C hem. A, 2019, 7, 493[6] M. Hojamberdiev et al., J. Mater. Chem. A, 2016, 4, 12807[7] T. Yamada et al., J. Phys. Chem. C, 2018, 122, 8037[8] S. Ramaraj et al. J. Energy Chem. 2022, 68, 529[9] N. C. Hildebrandt et al., Small, 2015, 11, 2051 [10] A. Bloesser et al., J. Mater. Chem. A, 2018, 6, 1971[11] A. Bloesser, R. Marschall, ACS Appl. Energy Mater. 2018, 1, 2520[12] A. Hofmann et al., Adv. Mater. Interfaces, 2021, 8, 2100813

Morphometric Analysis of Lateral Cervical Lymph Node Metastasis in Papillary Thyroid Carcinoma Using Digital Pathology.

Digital pathology uses digitized images for cancer research. We aimed to assess morphometric parameters using digital pathology for predicting recurrence in patients with papillary thyroid carcinoma (PTC) and lateral cervical lymph node (LN) metastasis. We analyzed 316 PTC patients and assessed the longest diameter and largest area of metastatic focus in LNs using a whole slide imaging scanner. In digital pathology assessment, the longest diameters and largest areas of metastatic foci in LNs were positively correlated with traditional optically measured diameters (R = 0.928 and R2 = 0.727, p < 0.001 and p < 0.001, respectively). The optimal cutoff diameter was 8.0mm in both traditional microscopic (p = 0.009) and digital pathology (p = 0.016) evaluations, with significant differences in progression-free survival (PFS) observed at this cutoff (p = 0.006 and p = 0.002, respectively). The predictive area's cutoff was 35.6 mm2 (p = 0.005), which significantly affected PFS (p = 0.015). Using an 8.0-mm cutoff in traditional microscopic evaluation and a 35.6-mm2 cutoff in digital pathology showed comparable predictive results using the proportion of variation explained (PVE) methods (2.6% vs. 2.4%). Excluding cases with predominant cystic changes in LNs, the largest metastatic areas by digital pathology had the highest PVE at 3.9%. Furthermore, high volume of LN metastasis (p = 0.001), extranodal extension (p = 0.047), and high ratio of metastatic LNs (p = 0.006) were associated with poor prognosis. Both traditional microscopic and digital pathology evaluations effectively measured the longest diameter of metastatic foci in LNs. Moreover, digital pathology offers limited advantages in predicting PFS of patients with lateral cervical LN metastasis of PTC, especially those without predominant cystic changes in LNs.

Thermal performance promotion of a novel double-tube heat exchanger by helical fin with perforations

Double-tube heat exchangers are widely used in many fields. A novel double-tube heat exchanger with a perforated helical fin on the annulus side is proposed in this paper for thermal performance promotion. The effect of different perforation diameters ranging from 0 to 12 mm on the fluid flow and heat transfer are numerically studied under a turbulent state with Re ranges between 4000 and 16,000. The results showed that perforation diameter has a significant influence on the thermal performance. There exists an optimum perforation diameter for the best thermal performance. The largest value of Nu in the helical finned annulus increases by 20.2% by perforation, while the corresponding f only increases by 11.0% compared with the normal helical finned configuration without perforation. The thermal performance evaluation factor JF is also improved by up to 16.1% compared with the helical finned configuration without perforation, and is increased by 48.6% compared with the smooth annulus. Correlation formulas of f, Nu, and JF are fitted and the deviations are within ±4%, ±9%, and ± 5% for f, Nu, and JF, respectively. Perforated helical fin is an efficient annular-side heat transfer enhancement technology that can be applied to the optimized design of double-tube heat exchangers.

Study case on the characteristics and performances of a propulsion system for a crude oil tanker

This paper presents aspects regarding the analysis of the characteristics and performances of a propulsion system for a crude oil tanker. The study involved several steps: first, the ship’s resistance and the necessary propulsive power were calculated to choose and design the main components: engine, transmission and propeller; to obtain maxim propulsive efficiency at the desired speed, with low fuel consumption and reduced CO2 emissions. Four slow Diesel engines were selected and the optimal propellers were designed to analyse and adopt the more efficient solution. A number of factors were taken into account for ship propulsion system components selection such as: required power, revolution rate to ensure an optimal propeller diameter to be located behind the ship, the specific fuel consumption parameters, desired ship speed, etc.

Off-the-Shelf Single-Fenestrated Endograft for Emergent Juxtarenal and Pararenal Abdominal Aortic Aneurysm.

Endovascular solutions to emergent juxtarenal and pararenal abdominal aortic aneurysms (AAAs) are complicated. Endovascular aortic repair (EVAR) with in situ laser fenestration (ISLF) is promising but requires a period of visceral ischemia. With an off-the-shelf, single superior mesenteric artery (SMA)-fenestrated device mesenteric ischemia is avoided and renal ischemia decreased. The aim was to develop an optimized design of such an endograft suitable for >90% of juxtarenal and pararenal AAAs. Single-center analysis on 44 consecutive preoperative CTs for previously elective fenestrated EVARs for juxtarenal and pararenal aneurysms. Anatomical characteristics were analyzed to define: (1) shortest aortic coverage above SMA fenestration to achieve ≥4 cm seal; (2) feasibility of a scallop for the celiac artery; (3) shortest distance between the SMA and lowest renal, to facilitate renal ISLF in a straight endograft; (4) distance from the lowest renal to the aortic bifurcation, to allow an overlapping zone >40 mm with a bifurcated stent graft; (5) aortic diameter in the sealing zone, for optimal proximal stent graft diameter with 10% to 30% oversizing; (6) the final design was then tested on individual level. (1) The stent graft needs to start 40 mm above the SMA fenestration to achieve a 4 cm sealing zone in >90% of cases. (2) A proximal sealing zone of 40 mm without a scallop covers 77% of celiac arteries. With an addition of a 20 mm deep, 20 mm wide scallop at 12:30, the stent graft still covers 27% of celiacs. This suggests that a scallop would not be practically feasible. (3) In >90% of cases, the lowest renal was <31 mm from the SMA, suggesting that the tapering should start 30 mm below the SMA. (4) The distance from the lowest renal to the aortic bifurcation ranged from 82 to 166 mm. This allows for a 20 mm tapering and 50 mm straight part in all cases. (5) The 5th and 95th percentile of the aortic diameter in the sealing zone was 22 and 31 mm, respectively. Thus, 2 different stent graft diameters (28 and 34 mm) would fit >90% of cases. (6) The final design was suitable in 91% cases. Two sizes of a single-fenestrated aortic stent graft without scallop cover >90% of juxtarenal and pararenal anatomies. Emergent juxta- and pararenal aortic aneurysms is a difficult clinical scenario that continuously challenges physicians. An endovascular option is in situ laser fenestrated endografts. One risk with these is the complete visceral ischemia occurring before the fenestrations are completed. An off-the-shelf single-fenestrated stent graft facilitates the treatment by removing the ischemia time for the SMA and reducing the ischemia time for the celiac and renal arteries thus decreasing the risk of visceral ischemia complications.

Optimizing geometrical parameters of coherent beam combining in the near and far-field distance

Determining the characteristics of the laser array to improve the performance of a laser system based on coherent beam combination (CBC) has continuously garnered interest. To this end, the parameters of the Gaussian beam waist, array shape, and distance between adjacent beams were studied and numerically investigated in this study. Consequently, the combined beam quality was compared for hexagonal, circular, and square arrays. The observing plane’s location was fixed at 10 km and varied from 0.25 to 10 km to investigate the effect of beam waist on combined beam quality in two modes (near and far field) using the power in the 5 cm bucket metric (PIB5cm). Furthermore, the average PIB5cm was investigated to determine all observing plane distances. The simulation results in two states of fixed and variable observing plane distances demonstrated that the hexagonal array has an advantage in attaining PIB5cm and higher combined beam quality. In addition, the quality of the combined beam degrades as the space between the beams increases. Moreover, the optimal beam waist and aperture diameter are independent of the array geometry and the vacancy between adjacent beams.

Mitigating the carbon footprint in Jordan by designing an artificial lake system to improve domestic tourism

This work investigates mitigating the carbon footprint in Jordan by altering the travel patterns of the population. This goal can be accomplished by creating a new tourist destination that has a marine environment, similar to overseas destinations. Based on recent data, it is estimated that half a million Jordanians would prefer a domestic destination instead of traveling abroad, provided that it has a marine environment. This shift in travel preferences would result in an estimated reduction of 320,000 tons of CO2 emissions every year. The proposed new destination is an artificial lake created in the Jafer basin, located in southeastern Jordan. The area has a natural depression that is suitable for this purpose. The proposal involves excavating a 140 km-long tunnel connecting the Gulf of Aqaba to the Jafer basin, where seawater is pumped into the basin to create the lake, with a water volume of 2000 MCM. The design is based on keeping the water's level steady in the lake. The proposed design is shown to be feasible, with an optimal tunnel diameter of 4 m, excavated at constant depth. In order to maintain a uniform water pressure, 15 pumping stations should be installed along the tunnel. The total cost of the project is estimated at 5.5 B$. This cost is not only used for mitigating carbon footprint but also for increasing the real estate value of the area around the lake, and a more healthy distribution of population in the country.

Energy efficiency of “hot” oil pipelines under partial load conditions

The article discusses trenchless methods of pipeline repair, which can be used in the repair of oil pipelines in conditions of incomplete loading. Trenchless pipeline reconstruction technologies are widely used due to certain advantages that ensure environmental safety and economic efficiency. Such technologies can be used in conditions where it is impossible to use open methods of repair, with minimal volumes of earthworks, without damage to existing underground communications, as well as when working in unstable soil conditions. The main attention is paid to the repair according to the “pipe in a pipe without destruction” scheme. The article is devoted to solving the optimization problem of choosing the diameter and wall thickness of the internal pipeline, which runs in the repaired one, according to the criteria of minimal heat loss at maximum throughput, in which energy costs for transporting the product will be minimal, which will allow obtaining maximum energy efficiency. The authors use analytical methods and conduct a study of the influence of changes in pipeline characteristics on product pumping parameters. The results of the study show that the methods of trenchless repair of “hot” oil pipelines are effective from an economic and energy point of view. The work established that during the repair of long “hot” oil pipelines with intermediate heating points, the selection of the diameter of the internal pipeline requires taking into account the energy consumption at these intermediate heating points. The work contains an algorithm for choosing the optimal diameter and wall thickness of the pipeline, which can be useful for oil transportation enterprises and energy companies to optimize work and reduce energy costs for transporting the product