Arc Of Rotation Research Articles

Adria microplate: a puzzling key stone in west-central Mediterranean geodynamics

The Mediterranean region denotes a special plate tectonic environment as the two big plates, Africa and Eurasia, primarily provide the main frame while the dominant players are the small oceanic basins and the continental micro plates (MP) that for the past 80 Ma was the Adria MP. In this environment slab rollback subduction, orogenic arc formation and rotation of crustal blocks are common. While the tectonic setting and involvement in geodynamic processes of Adria MP might not be unique in global terms, it presents Adria as an ideal natural laboratory to study the geodynamic processes individually and in their combined effects in a generally well-studied and rather wellaccessible region. The current extension of the Adria MP is defined by the continental Moho as far into the bounding orogens as the latter could be confirmed. The slabs surrounding Adria dominate and characterize the geodynamics of this MP and in most cases their geometries and the possible connection with Adria are well defined by tomographic images. The Ionian oceanic lithosphere slab subducting beneath Calabria has been torn off and detached from the very short South Apennines slab remaining attached to Adria. On the southeastern side we observe the Adria slab beneath the Hellenides that seems detached from the Ionian oceanic lithosphere slab of the Hellenic subduction zone. Along the Dinarides a slab gap is observed analogue to the slab window on Adria MP’s western side between the South Apennines and the North Apennines. Encircled by three orogens, the Adria continental lithosphere has been and still is strongly affected by the subductions surrounding it. In the northern part of the Adria MP, the North Apennines slab rollback is the obvious dominant geodynamic force acting locally on the plate while in contrast, the slabs beneath the Eastern Alps and beneath the Hellenides seem stagnant. This study presents a brief overview of the wealth of information aiming to summarize the main constraints on Adria MP available and it discusses some of the questions surrounding this key player in west-central Mediterranean geodynamics.

Study of the rotating arc on the tribological behavior of hardbanding for oil drilling tubes

In this work, four welded coupons were evaluated with a welding speed of 5, 9, 11 and 13 mm/s. A semi-automatic welding process was used under gas protection, using a 1.6 mm diameter tubular wire. The chemical composition was analyzed on each welded coupon, the dilution percentage was determined, the dimensional of the beads was carried out and the microstructure was characterized by optical microscopy and scanning electron microscopy. In addition, the Vickers microhardness HV2 in the middle of the bead were measured. It was found that the dilution decreased up to 22% (a decrease of 80% compared to traditional welds). Furthermore, the beads presented less refusion with the base material, increasing their width and penetration. A microstructure formed by an “α matrix” was observed, with complex metallic carbides and carboborides which increased in quantity when considering the effects of the rotating arc method Also, it was observed a microstructure formed by a matrix α with complex metal carbides and carboborides that increased in quantity with the effect of the rotating arc. The hardness of the beads varied between 720 and 780 HV2. The weight loss and the friction coefficient decreased with the application of the arc rotation. These changes would be related to the increase in non-metallic phases.

An Optimal Scalp Rotation Flap Design: Mathematical and Bio-Mechanical Analysis

The design and implementation of successful rotational flaps of the scalp remains a complex process. There are several described techniques, all of which are based on a two-dimension surface, absent consideration of the convexity and thereby three-dimensional nature of the scalp. This has contributed to flaps that are either too small or unnecessarily large in a bid to compensate.Mathematical analysis using trigonometric and algebraic formulae were used to derive the relationship between the defect, triangulation, the contour of the scalp, the radius of the arc of rotation for the flap and scalp skin tension. Polyurethane models were used to test the applicability of the resultant formula, and a consecutive clinical case series is presented.Rotation flap dimensions were calculated using an apex angle of 30 degrees depicted as a two-dimensional construct. The contour of the defect was then measured as the depth of depression with radius of the rotation flap calculated based on the changes in flap surface area across the defect. Finite Element Analysis was utilised to measure redistribution of tension along the flap reconstructing the defect, and the efficacy of the approach confirmed in the consecutive clinical series. The current study provides a reliable flap design based on mathematical analysis, with evidence-based application to the clinical setting.

Guidance for Circumflex Scapular Artery Flap Utilization in Pediatric Reconstruction.

The circumflex scapular artery (CSA) flap system, consisting of scapular, parascapular, and chimeric flaps, is useful for pediatric reconstruction in many anatomical locations. The objectives of this case series are to offer insights into our decision-making process for selecting the CSA flap in particular pediatric reconstructive cases and to establish a framework for choosing a scapular or parascapular skin paddle. We also aim to emphasize important technical considerations of CSA flap utilization in pediatric patients. Pediatric reconstruction with CSA flaps performed at our institution between 2006-2022 was retrospectively reviewed. Patient demographics, indications, flap characteristics, complications, and operative data were abstracted. Functional donor site morbidity was assessed through postoperative physical examinations. Unpaired t test analyzed scapular versus parascapular flap size. Eleven CSA flaps were successfully performed in 10 patients (6 scapular and 5 parascapular flaps). Patient ages ranged from 2 to 17 years. Scapular fasciocutaneous free flaps (n = 4) were performed in patients' ages 2-5 years for hand and forearm scar contractures. Two pedicled scapular flaps were performed for a single patient for bilateral axillary hidradenitis suppurativa. The 5 parascapular flaps were performed in patients' ages 2-14 years for calcaneus and forearm avulsion wounds and reconstruction after resection of hidradenitis suppurativa, nevus sebaceous, and Ewing sarcoma. In the sarcoma resection case, a chimeric flap with latissimus dorsi was employed. Average flap size was 101.6 ± 87.3 cm2 (range: 18-300 cm2). Parascapular flaps were significantly larger than scapular flaps (156.60 ± 105.84 cm2 vs 55.83 ± 26.97 cm2, P = 0.0495). Overall, 3 complications occurred (27.3% of cases) including venous congestion (n = 2) and wound dehiscence (n = 1). There were no reported cases of compromised shoulder function at 1.9 ± 2.5-year follow-up. The successful reconstruction rate for scapular, parascapular, and chimeric flaps was 100%. The CSA flap treated a wide variety of indications demonstrating the flap's attributes: large vessel caliber, wide arc of rotation, reliable vascular anatomy, minimal donor site morbidity, and ability to incorporate bone and muscle. Our cases also highlight important pediatric considerations such as vascular mismatch and limited scapular bone stock. We recommend selection of the parascapular over the scapular flap with reconstruction of larger, complex defects given its ability to be harvested with a large skin paddle.

Non-coplanar Arc-Involved Beam Arrangement With Sufficient Arc Rotations Is Suitable for Volumetric-Modulated Arc-Based Radiosurgery for Single Brain Metastasis

Non-coplanar Arc-Involved Beam Arrangement With Sufficient Arc Rotations Is Suitable for Volumetric-Modulated Arc-Based Radiosurgery for Single Brain Metastasis

Investigation of the effectiveness of a complex injury prevention programme among young swimmers

AbstractPurposeThe training load required at elite level can lead to shoulder pain even among the youngest swimmers, thus, besides modern water training plans and swimming technique development, the planning of dryland training with a preventive approach is of the utmost importance. The aim of the present study was to map kinetic patterns and sports injury risk factors among young competitive swimmers (between 9 and 12 years of age) and to investigate the effectiveness of a complex injury prevention programme on dry land.Materials and methodsA total of 37 swimmers (19 girls and 18 boys, aged 10.8 ± 1 yrs) participated in the research. We performed a physical examination using the PostureScreen11.1 application, a digital goniometer, a manual dynamometer, and functional and diagnostic orthopaedic tests. The swimmers were divided into a trained group and a control group. A three-month complex injury prevention programme was developed for the trained group. We analysed our data using Statistica for Windows.ResultsWe found that 19% of the swimmers had experienced shoulder pain since starting swimming. We also found several postural faults, a reduction in the rotational arc of motion in the shoulder joint, rotational muscle imbalance, serratus anterior weakness, and scapular dyskinesia. Following the programme, swimmers in the trained group showed significant improvement in the rotational arc of the shoulder joint, internal rotational range of motion, rotational muscle strength, and upper limb stability. Progress was also made in many other areas, although these results were not significant.ConclusionsAs shoulder pain and its risk factors can be observed even among the youngest competitors, a dryland training plan tailored to this group can reduce the occurrence of sports injuries.

Impact of tendon transfer on scapulothoracic and glenohumeral motion in children with brachial plexus birth injuries

BackgroundTendon transfers are often utilized to improve shoulder external rotation and abduction in children with brachial plexus birth injuries and are designed to improve glenohumeral (GH) joint motion. However, changes in scapulothoracic (ST) and glenohumeral (GH) joint function after tendon transfer are not well defined. The purpose of this study was to quantify changes in GH, ST, and humerothoracic (HT) joint function before and after tendon transfer, and we hypothesized that tendon transfers would reorient the arc of motion into more external rotation and abduction, but not increase GH motion. MethodsMotion analysis was performed in 15 children (ages 3-16) before and after transfer of teres major and/or latissimus dorsi. Scapulothoracic, GH, and HT joint angles were measured in a neutral, resting position and each of the modified Mallet positions. Joint angular displacements from the neutral position and the total arc of internal-external rotation for each joint were also calculated. Relevant joint angles, joint angular displacements, and internal-external rotation arcs were compared using multivariate analyses of variance with repeated measures and univariate post-hoc analyses. ResultsGlenohumeral and HT external rotation were significantly increased in all positions postoperatively. The arc of GH internal-external rotation was unchanged, but oriented in more external rotation after surgery. Only 6 patients gained active external rotation. Glenohumeral and HT internal rotation were significantly decreased after surgery, but ST internal rotation was significantly increased. Two patients had loss of midline function. In the abduction position, GH elevation joint angles were unchanged, but ST and HT elevation increased. DiscussionOnly four patients gained active GH external rotation and maintained their internal rotation. Each of those patients underwent isolated tendon transfer without concomitant joint release. Seven patients maintained their preoperative internal rotation, which was attributed to increased ST internal rotation. The other half of patients lost internal rotation and gained external rotation through reorientation of the arc of rotation. Nine patients gained HT elevation, with three attributed to increased ST upward rotation, five attributed to a combination of increased ST upward rotation and increased GH elevation, and one attributed to increased GH abduction contracture. These findings challenge the dogma that teres major/latissimus dorsi tendon transfers augment GH motion and highlight the importance of ST function for outcome determination.

Humeral Torsion in Relation to Shoulder Range of Motion in Elite Field Hockey Players.

Sport-specific adaptations in shoulder rotation range of motion (ROM) and the relationship with humeral torsion have been described in overhead-throwing sports. However, information is lacking for other shoulder-loading sports such as field hockey. Therefore, this study's purpose was to evaluate humeral torsion in elite, male field hockey players and explore its association with shoulder ROM. Cross-sectional study. Twenty-five male, elite field hockey players were included. Humeral torsion and shoulder external and internal rotation ROM were evaluated bilaterally by ultrasound and an inclinometer smartphone application, respectively. Field hockey players showed a significantly increased humeral retroversion on the dominant compared with the nondominant side (P < .001; Cohen d = 1.75), along with a significantly increased external (P = .004; Cohen d = -0.64) and decreased internal rotation ROM (P = .003; Cohen d = 0.65). This finding illustrates a shift in total shoulder rotational ROM arc. Correlation analysis showed a significant moderate association between the increased humeral retroversion and decreased internal rotation ROM on the dominant side (r = .523). Elite male field hockey athletes show sport-specific adaptations regarding humeral torsion and shoulder rotation ROM, similar to throwing athletes. These findings increase our insight into the field hockey athlete's shoulder, which is essential to optimize performance and assist in correctly interpreting shoulder rotational ROM measurements.

A Supraorbital V-Y Myocutaneous Perforator Flap for Forehead Reconstruction.

V-Y flaps vascularized by perforators have gained great popularity in the last years. The advantages over randomized local flaps are the significantly greater arc of rotation and transfer length as well as less lymphatic congestion. We introduce a supraorbital V-Y myocutaneous perforator flap for forehead reconstruction. The vascular basis of this flap are the perforators from the ophthalmic artery passing through the supraorbital foramen and incisura frontalis.

The Forgotten Flap: The Pedicled Trapezius Flap's Utility in Pediatric Head and Neck Reconstruction-A Systematic Review.

When free tissue transfer is precluded or undesired, the pedicled trapezius flap is a viable alternative for adults requiring complex head and neck (H&N) defect reconstruction. However, the application of this flap in pediatric reconstruction is underexplored. This systematic review aimed to describe the use of the pedicled trapezius flap and investigate its efficacy in pediatric H&N reconstruction. A systematic review was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Articles describing the trapezius flap for H&N reconstruction in pediatric patients were included. Patient demographics, surgical indications, wound characteristics, flap characteristics, complications, and functional outcomes were abstracted. A systematic review identified 22 articles for inclusion. Studies mainly consisted of case reports (n = 11) and case series (n = 8). In total, 67 pedicled trapezius flaps were successfully performed for H&N reconstruction in 63 patients. The most common surgical indications included burn scar contractures (n = 46, 73.0%) and chronic wounds secondary to H&N masses (n = 9, 14.3%). Defects were most commonly located in the neck (n = 28, 41.8%). The mean flap area and arc of rotation were 326.4 ± 241.7 cm2 and 157.6 ± 33.2 degrees, respectively. Most flaps were myocutaneous (n = 48, 71.6%) and based on the dorsal scapular artery (n = 32, 47.8%). Complications occurred in 10 (14.9%) flaps. The flap's survival rate was 100% (n = 67). No instances of functional donor site morbidity were reported. The mean follow-up was 2.2 ± 1.8 years. This systematic review demonstrated the reliability of the pedicled trapezius flap in pediatric H&N reconstruction, with a low complication rate, no reports of functional donor site morbidity, and a 100% flap survival rate. The flap's substantial surface area, bulk, and arc of rotation contribute to its efficacy in covering soft tissue defects ranging from the proximal neck to the vertex of the scalp. The pedicled trapezius flap is a viable option for pediatric H&N reconstruction.

Comparison of the forearm rotation restriction capacities of four upper-extremity immobilization methods: there is no difference between single and double sugar tong splinting

BackgroundThe aim of this study was to compare the effects of four different immobilization methods [single sugar tong splint (SSTS), double sugar tong splint (DSTS), short arm cast (SAC), and long arm cast (LAC)] commonly used for restricting forearm rotation in the upper extremity.MethodsForty healthy volunteers were included in the study. Dominant extremities were used for measurements. Basal pronation and supination of the forearm were measured with a custom-made goniometer, and the total rotation arc was calculated without any immobilization. Next, the measurements were repeated with the SAC, LAC, SSTS and DSTS. Each measurement was compared to the baseline value, and the percentage of rotation restriction was calculated.ResultsThe most superior restriction rates were observed for the LAC (p = 0.00). No statistically significant difference was detected between the SSTS and DSTS in terms of the restriction of supination, pronation or the rotation arc (p values, 1.00, 0.18, and 0.50, respectively). Statistically significant differences were not detected between the SAC and the SSTS in any of the three parameters (p values, 0.25; 1.00; 1.00, respectively). When the SAC and DSTS were compared, while there was no significant difference between the two methods in pronation (p = 0.50), a statistically significant difference was detected in supination (p = 0.01) and in the total rotation arc (p = 0.03).ConclusionThe LAC provides superior results in restricting forearm rotation. The SAC and SSTS had similar effects on forearm rotation. The DSTS, which contains, in addition to the SSTS, a sugar tong portion above the elbow, does not provide additional rotational stability.

A Numerical Study on the Influence of External Magnetic field on Hydrogen Electric Arc Flow

We present a 3D numerical model capable of simulating hydrogen electric arc. The numerical model couples the electromagnetic field with hydrogen plasma arc dynamics (flow and heat transfer). Electric arc operates under the conditions of atmospheric pressure using direct current (DC) in the presence of external magnetic field. It is found that arc instabilities emerge spontaneously near the cathode before propagating downwards along the arc jet. Also, spontaneous splitting into several arcs is observed before merging again into one arc. The horizontal magnetic field induces arc skewing and directional flow perpendicular to the applied magnetic field. However, the axial magnetic field induces a rotational flow and arc swirling.

Evaluation of the subclavicular route for the pectoralis major flap in oral and maxillofacial reconstruction- Our 15 years experience

Purpose: The pectoralis major flap (PMF) is an important reconstructive tool for defects in the head and neck region but excessive bulk and a limited arc of rotation can be problematic. These problems can be addressed by passing the pedicle deep to the clavicle but some authors feel that this modification may compromise the vitality off the flap. In the current article, these problems have been addressed by using a modified method.&#x0D; Patients and methods: During the past 15 years (2000 to 2014) 182 head and neck cancer patients were treated for primary reconstruction following tumor ablation. PMF was modified by passing the pedicle deeply to the clavicle. Following flap harvest, the pedicle was passed in the subclavicular plane for reconstruction.&#x0D; Results: It was possible to increase the average length of PMF to 2.5-3.5 cm compared to the supraclavicular route by using this modification. Minor complications were observed in 9 of 182 cases (5%): Partial flap necrosis occurred in 6 cases and fistula formation was observed in 3 cases.&#x0D; Conclusions: The subclavicular route increases the length and arc of rotation without compromising vascular supply to a higher degree compared to the conventional supraclavicular route. Furthermore, this concept decreases the bulk of the flap pedicle which is functionally and cosmetically favourable.

Extended arc of rotation of Latissimus Dorsi Musculocutaneous Flap providing well-vascularized tissue for reconstruction of complete defects of the sternum: An anatomical study of flap pedicle modification.

Deep sternal wound infections (DSWI) following cardiothoracic surgery represent a life quality endangering sequelae and may lead to sternal osteomyelitis. Radical debridement followed by Negative Pressure Wound Therapy (NPWT) may achieve infection control, provide angiogenesis, and improve respiratory function. When stable wound conditions have been established a sustainable plastic surgical flap reconstruction should be undertaken. This study analyses a method to simplify defect coverage with a single Latissimus Dorsi Myocutaneous Flap (LDMF). Preparation of 20 LDMF in ten fresh frozen cadavers was conducted. Surgical steps to increase pedicle length were evaluated. The common surgical preparation of LDMF was compared with additional transection of the Circumflex Scapular Artery (CSA). Alteration of the surgical preparation of LDMF by sacrificing the CSA may provide highly valuable well-vascularized muscle tissue above the sensitive area of the Xiphisternum. All defects could be completely reconstructed with a single LDMF. The gain in length of flap tissue in the inferior third of the sternum was 3.86±0.9 cm (range 2.2 to 8 cm). By sacrificing the CSA in harvesting the LDMF a promising gain in length, perfusion and volume may be achieved to cover big sternal defects with a single flap.

Accuracy of the Lesser Trochanter Profile as a Marker of Femoral Rotation: Computed Tomography-Based Study of 1,722 Femora.

The lesser trochanter (LT) profile is an often-used marker for proximal femoral rotation, particularly during the operative fixation of femoral fractures. Previous studies have come to conflicting conclusions about its reliability for this purpose. The SOMA (Stryker Orthopaedic Modeling and Analytics) database (Stryker) was used to identify 1,722 computed tomographic (CT) scans of whole femora. Each femur was taken through an 80° rotational arc in 2.5° increments, and the LT profile was constructed for each position. These 56,826 LT profile measurements were then correlated with the femoral rotation. Across the arc of motion studied, the LT correlated weakly with proximal femoral rotation (R 2 = 0.32). There was a 35° arc, between 10° and 45° relative external rotation of the proximal femur, within which the LT profile only changed by 1 mm. The mean overall femoral anteversion was 21.2°, and women tended to have more femoral anteversion (23.9°) than men (19.2°). On average, men had a 1.6-mm more prominent LT than women. Side-to-side differences in femoral anteversion as well as LT position and size were not significant or were clinically unimportant. A large-scale, CT-based study shows that the LT profile is a less reliable marker of proximal femoral rotation than previously thought. This is true particularly if there is relative external rotation of the proximal femur, where the proximal femur can undergo up to 35° of rotation before 1 mm of change in the LT profile occurs. Care must be taken to check other markers of rotation such as by clinical examination during fixation of femoral fractures and not rely solely on the LT profile. In the largest study of its kind, this CT-based study of 56,826 LT profile measurements found that when the proximal femur is externally rotated, the LT profile becomes an unreliable marker of rotation, which can lead to excessive internal rotation of the distal fracture fragment. The LT profile should be used with caution, and confirmation of rotation by other means is recommended.

Anatomic feasibility study of a sartorius myocutaneous flap with a distally based pedicle and proximal skin paddle

IntroductionWe conducted an anatomic feasibility study of a sartorius myocutaneous flap with a distally based pedicle and proximal skin paddle to cover soft tissue defects of the knee region. HypothesisA recent anatomic study by Mojalla showed that the sartorius muscle had 2 distinct pedicles, making it possible to isolate this muscle on its distal pedicle and harvest it with a skin paddle. Materials and methodsThis anatomic study was conducted on 10 lower limbs. The 2 criteria assessed were (1) the viability of our proximal skin paddle and (2) the arc of rotation and coverage obtained with this myocutaneous flap. ResultsWe identified 7 proximal skin paddles after the injection of India ink into the distal pedicle of the sartorius muscle. In all cases, the arc of rotation of the flap allowed coverage of the knee region. The mean distance between the inferior edge of the skin paddle and the proximal border of the patella (DBAP) was measured at 13cm, and the mean distance between the superior edge of the flap paddle and the anterior superior iliac spine (DASIS) at 16cm. The average skin paddle size was 14 by 7cm. DiscussionOur anatomic study demonstrated the feasibility of our sartorius flap with a distally based pedicle and proximal skin paddle. This technique may be a viable alternative when using gastrocnemius flaps is not feasible, or the surgeon lacks the microsurgical skills to perform free flaps. Level of evidenceIV; descriptive anatomic study.

Nitrogen fixation by rotational gliding arc plasma at surrounding conditions

Nitrogen fixation (NF) was investigated in a rotational gliding arc plasma based on various energy inputs, flow rates, and N2:O2 ratios under atmospheric conditions. For practical application, the effect of water content in the feed, self-heating during plasma discharge, prolonged operation, and comparison between plasma and thermal process for N2 oxidation were also conducted. The comparison results reveal that NF by the gliding arc plasma is superior to the thermal process in terms of NOx yield and energy consumption at low temperatures and atmospheric pressure. Herein, energy input and flow rate are two controlled factors that significantly influence NOx production rate. Simultaneously, O2 content played a crucial role in determining NOx yield, selectivity of NO/NO2, and energy consumption. Observations during plasma discharge indicated an initial rise in gas and reactor body temperatures, coinciding with decrease in total NOx formation. Moreover, the presence of water had a negative effect on NOx yield. Accordingly, the optimized conditions for NF by gliding arc plasma for NOx formation was identified at a N2 to O2 ratio of 3:2 without water vapor in the feed gas. Furthermore, a 14-h continuous operational test validated the robustness of our reactor configuration, affirming its long-term viability. The study concludes by performing oxidation of the NOx gas followed by dissolution in water, successfully generating nitric acid. These findings underscore the potential of gliding arc plasma for efficient NF processes, offering insights into optimal operational conditions and downstream applications for nitric acid generation.

Simulation Study of Critical Aspects of MIAB Welding for Analysis of Potential Factors Governing the Performance of Weld Formation

Magnetically Impelled Arc Butt (MIAB) welding, is a solid-state welding technique. The magnetic system of this technique is pivotal for the generation of the Lorentz force, which impels an arc to rotate along the periphery of the weld tubes and thus facilitates the heating of faying surfaces. The magnetic arrangement and the arc dynamics significantly impact the effectiveness of the welding process, eventually dictating the efficiency. This study case investigates the impact of the magnetic arrangement on the arc rotation and possible factors that cause irregularities in the (MIAB) welding through COMSOL simulation. The COMSOL simulation has served as a powerful tool to comprehensively analyse various arc dynamics and magnetic systems and extrapolate the observations to analyse the arc dynamics and magnetic systems involved in MIAB welding. By employing simulation studies, the research aims to unravel critical insights for an efficient design of the MIAB welding system. This work includes a study of the effect of magnetic forces on arc dynamics using various models and attempts to develop an analogy to the MIAB welding process. This is further utilized to explain the process variations in the form of arc displacement, electric potential distribution, and the possibility of self-demagnetization of AlNiCo magnets. Thus, it provides a foundation for advancing the technological aspects of MIAB welding to overcome the limitations and irregularities. This research is instrumental in enhancing the understanding of magnetic interactions involved in the MIAB process, which can further pave the way for improved welding machine designs and consequently, enable research on these lines that can help in establishing an optimized parametric window.

Small half‐graben inferred from a Miocene syn‐rift succession in the Kinbusan area, eastern Tottori Prefecture, Japan

AbstractUnderstanding the Miocene tectonics of the southwest Japan Arc is key to elucidating the history of the opening of the Japan Sea, and important advances have been made in the last 10 years, such as clarification of the timing of arc rotation. Syn‐rift successions occur in the eastern San'in basins, but they have received little attention because the basic stratigraphy and development of the basins are poorly understood. This paper provides details of a field survey of the Miocene geology of the Kinbusan area in eastern Tottori Prefecture, Japan. The lithofacies suggest alluvial fan and plain environments, which correlate with the syn‐rifting horizon of the southwest Japan Arc. A syn‐depositional graben, which is newly named the Kinbusan Graben, can be inferred from the geometry of the basin fill, and this graben consists of two sub‐basins bounded by two ENE–WSW‐trending normal faults. Miocene dikes also trend ENE–WSW, indicating that the graben was formed in response to extension oriented perpendicular to the strike of the faults. The age of the Iwami Formation shows that extension was initiated before arc rotation. Fault‐slip data, collected from meso‐scale faults in the basin fill, indicate axial compressive stress with the maximum principal stress being vertical. The stress field suggests that the basin fill was accommodated not only in fault‐perpendicular extension but also in fault‐parallel extensions, and fault‐parallel extension was the probable cause of differential subsidence of the basin fill during faulting. The results show that the basic stratigraphy and structures of the eastern San'in basins provide important constraints on the timing and style of deformation in the southwest Japan Arc and the Japan Sea.

Research on key influencing factors and mechanisms of improved nitrogen fixation efficiency in magnetic-driven gliding arc

Gliding arc is considered to be an efficient method for nitrogen fixation. In this study, an improved magnetic-driven rotating gliding arc method was adopted to investigate the effects of gas flow rate, current, magnetic field, nitrogen-to-oxygen ratio in the working gas, and relative humidity on nitrogen fixation efficiency. To further understand the relationship between the discharge mechanism and nitrogen fixation efficiency, the arc length, arc diameter, arc rotation frequency, and reaction pathway were studied to find the relationship between external parameters, discharge characteristics, and nitrogen fixation efficiency. The research results indicate that the discharge current and magnetic field not only change the rotation frequency of the gliding arc, but also affect its length and diameter, and the amount of ionizing gases involved in the working gas, thus affecting nitrogen fixation efficiency. When the nitrogen volume ratio in the feed gas is 60%, the lowest energy cost can be achieved, which is 18.6% lower than that of air. The energy cost of nitrogen fixation is closely related to the humidity of the air. As the humidity increases, the energy cost also increases. At the magnetic field strength of 160 mT, gas flow rate of 10 l min−1, and current of 40 mA, the energy cost of 1.708 MJ mol−1 is realized which is the current lowest for plasma nitrogen fixation in this study.