Half Circumference Research Articles

Experimental study on preheating and salt circulation performance of a single receiver tube based on induction heating

The design of a light source for a molten salt receiver experimental system has become challenging owing to the complex heating characteristics of the half-circumference surface during operation. Electromagnetic induction heating is an innovative technology that can replicate a half-circle heating scenario. However, its feasibility must be verified. In this study, we constructed a single receiver tube experimental system using induction heaters and developed a 3D numerical model coupling electromagnetic field to analyze the tube temperature distribution and molten salt temperature rise during preheating and salt circulation, considering various parameters. The results indicated that the numerical simulation agreed well with the experimental results, and the induction heater successfully reproduced the half circumference heating scenario. During preheating, a lower heat flux and higher wind speed result in a more uniform temperature distribution along the circumference of the tube wall, facilitating comprehensive preheating. During salt circulation, the heat flux and inlet salt mass flow significantly affected the temperature of the tube wall but had a relatively small effect on the back-side wall. Wind speed had the opposite effect, which was related to the arrangement of the experimental site. A higher heat flux, lower wind speed, and higher inlet salt mass flow led to a higher temperature increase in the molten salt.

Conjugate heat transfer of a turbulent tube flow of water and GaInSn with azimuthally inhomogeneous heat flux

An experimental study of the conjugate heat transfer in a turbulent tube flow with azimuthally homogeneous and inhomogeneous heat flux distribution, where the tube is heated with a constant heat flux only over the half circumference, is presented. Using two fluids with clearly different Prandtl numbers (water and a liquid metal alloy), thermohydraulic effects that occur when fluids with very low Prandtl number are used in contrast to ordinary fluids (e.g. water with Pr≈1) are discussed. The test section is validated with water (Pr=5−7.4) for a Reynolds number in the range of 5·103<Re<4.2·104. The experimental data agree excellently with literature data. The maximum nondimensional temperature at the inner surface of the tube is expressed using a simple relationship based on the efficiency of a fin with an adiabatic tip. A near eutectic alloy of gallium, indium and tin (GaInSn, Pr=0.03) is used for the liquid metal experiments. The Péclet number is varied within the range of 240<Pe<3·103. Based on the experimental data of this work, an adapted correlation for the Nusselt number in a turbulent liquid metal tube flow with azimuthally homogeneous heat flux is provided:Nu=4.364+0.0276·Pe0.803The experimental data underlines, that the azimuthally averaged Nusselt number for an azimuthally inhomogeneous heat flux distribution can also be calculated with this correlation with an acceptable level of accuracy. Remarkably, the ratio of the local convective heat transfer coefficient to the azimuthally averaged value for GaInSn reaches a value up to 0.6 at the location of the maximum wall temperature. This is in strong contrast to water, where this ratio is close to unity.

Proposal for a Display Method for Myocardial Single Photon Emission Computed Tomography Based on Left Ventricular Volume.

Bull's eye view for the display of myocardial single-photon emission computed tomography (SPECT) 3-D perfusion maps does not reflect left ventricular (LV) volume, an important parameter. We created and evaluated a myocardial SPECT display method that reflects the LV volume.Using Digital Imaging and Communications in Medicine data, short-axis slices from the apex to the base were reconstructed and interpolated into 0.5-mm thickness. We obtained the radial lengths at 1° intervals throughout 360°, and calculated the length of the LV long axis and half circumference (1/2 circ). Myocardial perfusion was displayed as 2 ellipsoidal developments that exhibited the left anterior descending coronary artery (LAD) and non-LAD regions. We created a system that can display these processes on a personal computer. Myocardial SPECT data from 526 individuals without heart disease were analyzed. The long axis and 1/2 circ were compared with the body size, LV end-diastolic diameter (LVDd) obtained by echocardiography, and the end-diastolic volume (EDV) obtained by electrocardiogram-gated SPECT analysis. The 1/2 circle correlated with the LVDd and EDV. The images obtained allowed a diagnosis comparable to that made using the conventional coordinate display system.The new myocardial display reflects ischemia and LV volume within a single image, which cannot be achieved with conventional SPECT image display. Additional studies of this display system are required to allow its application to patients with heart disease.

New species of Temnocephala (Platyhelminthes, Temnocephalidae) ectosymbiont on decapod crustaceans Aegla jarai (Aeglidae) from Brazil and Samastacus spinifrons (Parastacidae) from Chile

A new Neotropical temnocephalan species is described from Aegla jarai Bond-Buckup & Buckup, 1994 from Santa Catarina, Brazil and recorded on Samastacus spinifrons (Philippi, 1882) from five locations (Región de Biobío, Región de la Araucanía, and Región de Los Lagos) in Chile. Temnocephala catarinensis sp. nov. differs from 10 other species of Temnocephala Blanchard, 1849 epibionts on Aeglidae Dana, 1852 and/or Parastacidae Huxley, 1879 by having the following combination of characters: 1. a long and slightly curved cirrus; 2. an introvert with two distinct portions, a proximal one with grooves and no spines and a distal one with small spines with a strong base; 3. a single vaginal sphincter, well-developed and slightly asymmetrical; 4. a very short vagina with a weak muscular wall; 5. an almost triangular epidermal 'excretory' syncytial plates, with external margin in half circumference, sometimes reaching laterally the margin of body. The specimens of S. spinifrons have slightly larger measurements than specimens of A. jarai. The cirrus total length and introvert length, despite being larger, have almost the same number of spines in the distal portion. The shape of the EPs is similar in specimens from both hosts. The new species share some similarities with Temnocephala axenos Monticelli, 1898, Temnocephala mexicana Vayssière, 1898, Temnocephala kingsleyae Damborenea, 1994, and Temnocephala mertoni Volonterio, 2007, but the characters that differentiate them are presented and discussed. The new species has a wide geographic distribution represented by a large distance between the sampled locations (2,637 km) and separated by the Andes. This is not the only species with very distant records from each other as Temnocephala iheringi Haswell, 1893 and T. axenos or separated by the Andes as Temnocephala chilensis (Moquin-Tandon, 1846) and Temnocephala monticellii Ponce de León, Rudolph and Volonterio, 2020.

Numerical study of convective heat transfer to supercritical CO2 in vertical heated tubes

Supercritical heat transfer is important to design and operate advanced power generation system. Non-uniform heating is frequently encountered such as for sCO2 boiler and solar receiver applications. Here, 3D numerical simulations are performed in turbulent regime, coupling solid wall and sCO2 in tubes. Non-uniform heating is simulated by applying heat via a thin metal layer at the outer tube wall, covering half circumference of tube wall. Calculation results matched experimental data well. Heat transfer is compared between uniform heating and non-uniform heating. Numerical results are re-processed by the pseudo-phase transition theory, including a liquid-like region in tube core and a gas-like layer near the tube wall. The two layers of structure are interfaced by a terminating temperature T+ which is determined by thermodynamics. Hence, supercritical heat transfer is evaluated based on the relative importance of thermal resistances induced by the liquid-like region and the gas-like film region. It is found that wall temperatures for uniform heating are higher than those for non-uniform heating, which is explained by larger thermal resistance of the gas-like film for uniform heating than that for non-uniform heating. This difference ensures better heat transfer for non-uniform heating than uniform heating. We conclude that in turbulent regime, the gas-like film dominates the magnitudes of wall temperature and the occurrence of heat transfer deterioration for both uniform and non-uniform heating. Our work is important for heat transfer facilities in supercritical domain, especially under non-uniform heating condition.

A comparison of fitting criteria for circle arc measurement applications

Measuring circular shape is a main task of dimensional metrology, characterized by circle diameter and its roundness, both for full circles and circle arcs. Point coordinates allows measuring both arcs and full circle, by fitting to substitution geometry, in many cases by least-squares criteria and fitting. Nevertheless, circle shape can be also characterized by the minimum zone, minimum circumscribed and maximum inscribed circles. This research presents a systematic experimental analysis of results of normal distributed points around the substitution circle through simulation, for different circle arc angles to the full circle and for the four mentioned fitting criteria. The results show the influence of arc angle in the variability of the results across criteria and the different behaviour depending on the arc amplitude. The results confirm the good stability and behaviour of least squares and minimum zone criteria, while warns the use of minimum circumscribed and maximum inscribed circles over half circumference. Experimental regression facilitates estimation of the minimum zone criteria from the least squares fitting that are independently verified with literature datasets with good results.

Dimples in turbulent pipe flows: experimental aero-thermal investigation

An experimental investigation is performed to study the effects of turbulent flow structures on the wall heat transfer, specifically inside the spherical cavities of partially dimpled tubes. The geometry under investigation consists of an array of spherical cavities distributed over the inner surface of half a tube. Each row has five indentations separated by an angular offset of 36° over the half circumference. The dimples are characterized by a depth-to-print diameter (d/Dp) of 0.18, a print diameter-to-pipe diameter (Dp/D) of 0.25, and a streamwise distance (xd/D) between consecutive cavities of 0.56. At Re=20000, flow separation, reattachment, and secondary flows are captured using both planar Particle Image Velocimetry (PIV) and stereo-PIV. The time-averaged flow field, the vorticity levels, and Turbulent Kinetic Energy (TKE) fields inside the dimples can be used for numerical validation. Moreover, the local heat transfer field inside the cavity is measured for Re=20000−80000, by using Liquid Crystals Thermography (LCTG). At the same Re and Pr, an overall heat transfer enhancement of 1.8 (1.8 times the Nusselt number value (Nu) in bare pipes) has been measured. The use of dimples in heat exchangers thus results in a rise in thermal efficiency at the cost of an increased pressure drop. Comparing the skin friction coefficient (Cf) of the dimpled pipe with the one measured in ribbed tubes for Re=20000−80000, it is shown that higher levels of the aerothermal performance (high heat transfer and low-pressure losses) are achieved by employing the dimple technique.

Analysis of the relationship among maxillary anterior teeth width, anterior arch perimeter and anterior segment depth

To analyze the relationship between the width of the maxillary anterior teeth and the anterior arch perimeter, to analyze the change rule of the width of the anterior teeth and the anterior arch perimeter, when altered the convexity of the anterior arch, with the width of the maxillary anterior arch keeping constant, and to provide a reliable basis for later digitized and personalized aesthetic analysis of front teeth. In the study, 61 front teeth complete and well-arranged models had been selected from the working models after the prostheses in Department of Prosthodontics, Peking University School and Hospital of Stomatology, including 22 male models and 39 female models. A photograph was taken from the occlusal surface of each model using the fixed magnification with a single lens reflex camera. The width of anterior teeth, the width of anterior arch and the convexity of anterior arch had been measured using the Photoshop software. The ratio of the width of the anterior teeth to the width of the anterior arch was calculated. Keeping the width of anterior arch unchanged, the layer free transformation function used to add or decrease the curvature of the anterior arch from 1-5 mm, each circumference of the anterior arch was measured. According to the proportion of their anterior teeth in the anterior arch perimeter, the width of each anterior teeth crown under different convexities of anterior arch was calculated. SPSS 23.0 was used to analyze the ratio of the width anterior teeth to the anterior arch perimeter and correlation between the convexity of the anterior arch and the width of the anterior teeth. The percentages of the median length of the anterior arch in the central incisor, lateral incisor and canine were 36.2%±1.3%, 30.2%±1.5%, and 33.6%±1.4%, respectively. The proportions were normal distributions and not related to the perimeter of the anterior arch. When the width of the anterior arch was constant, there was a positive correlation between the convexity of anterior arch in the range of 5 mm and the width of anterior teeth or the front arch circumference. With each increase or decrease of 1 mm of the convexity of anterior arch, the width of the middle incisor increased or decreased by about 0.18 mm, the half circumference of the anterior arch increased or decreased by about 0.50 mm. The width of the anterior teeth in the middle-distal direction remained stable in the anterior arch circumference. Within a certain range, when the width of the maxillary anterior arch remains unchanged, the width of the anterior teeth and the perimeter of the anterior teeth are positively correlated to the convexity of the anterior arch.

Three-dimensional morphogenesis of the omental bursa from four recesses in staged human embryos.

The omental bursa (OB) is a complex upper abdominal structure in adults. Its morphological complexity stems from embryonic development. Approximately 200years ago, the first theory regarding OB development was reported, describing that the OB developed from changes in the position of the stomach and its dorsal mesentery. Thereafter, the second theory reported that the OB originated from three recesses: the right pneumato-enteric recess (rPER), hepato-enteric recess (HER), and pancreatico-enteric recess (PaER). However, the first theory, focusing on the rotation of the stomach, is still described in certain modern embryology textbooks. These two coexisting embryological theories deter the understanding of the anatomical complexity of the OB. This study aimed to unify these two theories into realistic illustrations. Approximately 10 samples per stage among Carnegie stage (CS) 13 and CS21 were microscopically observed and histological serial sections of the representative samples were aligned using the new automatic alignment method. The aligned images were segmented computationally and reconstructed into 3D models. The rPER and the HER encompassed the right half circumference of the esophagus and the stomach at CS13 and CS14, the PaER spread dorsal to the stomach and formed a discoid shape at CS15 and CS16, the infracardiac bursa (ICB) was separated by the diaphragm at CS17 and CS18, and the fourth recess, which we called the greater omental recess (GOR), extended caudally from the PaER among CS19 and CS21. The present results indicate that the fourth recess is also the origin of the OB. These two theories over 200years can be generally unified into one embryological description indicating a new recess as the origin of the OB.

Preoperative surgical risk stratification in osteosarcoma based on the proximity to the major vessels.

The aim of this study was to determine the risk of local recurrence and survival in patients with osteosarcoma based on the proximity of the tumour to the major vessels. A total of 226 patients with high-grade non-metastatic osteosarcoma in the limbs were investigated. Median age at diagnosis was 15 years (4 to 67) with the ratio of male to female patients being 1.5:1. The most common site of the tumour was the femur (n = 103) followed by tibia (n = 66). The vascular proximity was categorized based on the preoperative MRI after neoadjuvant chemotherapy into four types: type 1 > 5 mm; type 2 ≤ 5 mm, > 0 mm; type 3 attached; type 4 surrounded. Limb salvage rate based on the proximity type was 92%, 88%, 51%, and 0% for types 1 to 4, respectively, and the overall survival at five years was 82%, 77%, 57%, and 67%, respectively (p < 0.001). Local recurrence rate in patients with limb-salvage surgery was 7%, 8%, and 22% for the types 1 to 3, respectively (p = 0.041), and local recurrence at the perivascular area was observed in 1% and 4% for type 2 and 3, respectively. The mean microscopic margin to the major vessels was 6.9 mm, 3.0 mm, and 1.4 mm for types 1 to 3, respectively. In type 3, local recurrence-free survival with limb salvage was significantly poorer compared with amputation (p = 0.025), while the latter offered no overall survival benefit. In this group of patients, factors such as good response to chemotherapy or limited vascular attachment to less than half circumference or longitudinal 10 mm reduced the risk of local recurrence. The proximity of osteosarcoma to major blood vessels is a poor prognostic factor for local control and survival. Amputation offers better local control for tumours attached to the blood vessels but does not improve survival. Limb salvage surgery offers similar local control if the tumour attachment to blood vessels is limited. Cite this article: Bone Joint J 2019;101-B:1024-1031.

Bacterial Contamination of Circuit Inner Surfaces After High-Flow Oxygen Therapy.

During high-flow oxygen therapy, heated humidified gas is delivered at high flow. Although the warmth and humidity of this gas facilitates mucociliary function in the lower airway, warm and humid conditions also promote bacterial growth. Bacterial contamination of high-flow oxygen therapy circuits has not been well investigated. We examined the incidence of bacterial contamination in high-flow oxygen therapy circuits. This was a prospective observational study in a university hospital 10-bed general ICU. After final high-flow oxygen therapy discontinuation, samples were obtained from the interface and the chamber ends of the circuit. Initially, a half circumference of each inner surface was swabbed, after which the whole circuit was left in the ICU at room temperature for 6 h. The samples were then, in the same way, taken from the previously unswabbed arcs of the end inner surfaces. All the samples were sent to a biology laboratory and cultured. In all, 118 samples were collected from 31 circuits. The median duration of high-flow oxygen therapy was 48 h (interquartile range, 26-96 h). Of 31 circuits, contamination occurred in 5 circuits (16.1% [95% CI 5.5-33.7%]). Bacterial contamination of inner surfaces of the circuit after high-flow oxygen therapy was relatively high.

Malignant colo-duodenal fistula: management based on proposed classification

Duodenal involvement in colonic malignancy is a rare event and poses challenge to surgeons as it may entail major resection in a malnourished patient. Nine patients with malignant colo-duodenal fistula were reviewed retrospectively. Depending on the pattern of duodenal involvement, it was classified as-type I involving lateral duodenal wall less than half circumference; type II involving more than half circumference away from papilla; type III involving more than half circumference close to papilla. Type I was managed with sleeve resection, type II with segmental and type III with pancreaticoduodenectomy. Median age was 47years, with male to female ratio of 2:1. Eight patients had anemia and seven had hypoproteinemia. Tumor was located in right colon in eight patients and distal transverse colon in one. Diagnosis of fistula was established by CT abdomen in seven (78%), foregut endoscopy in three and intraoperatively in two patients. Two patients had metastatic disease. Elective resection was done in seven while two required emergence surgery. Five patients underwent sleeve resection of the duodenum, two underwent segmental resection and two required pancreaticoduodenectomy. All patients had negative resection margin. One patient died. Median survival was 14months in eight survivors. Duodenal resection in malignant colo-duodenal fistula should be tailored based on the extent and pattern of duodenal involvement. Negative margin can be achieved even with sleeve resection. En bloc pancreaticoduodenectomy is sometimes required due to extensive involvement. Resection with negative margin can achieve good survival.

Studies on leakage characteristics and efficiency of a fully-rotary valve energy recovery device by CFD simulation

Seawater reverse osmosis (SWRO) develops rapidly and benefits from excellent performance of isobaric energy recovery devices (ERDs). Leakage characteristics directly affect the ERD performance. In this paper, leakage characteristics of a fully-rotary valve energy recovery device (FRV-ERD) which is a new type of isobaric ERD are studied numerically. Leakage variation of the fully-rotary valve (FRV) that is the key part of the device caused by pressure difference and geometric parameters is investigated. Then performance of the FRV-ERD is discussed. Results indicate that leakage rates of forward and reverse leakage within the same FRV are almost equal to each other and present a good linear relationship with pressure difference. Leakage rate is exactly proportional to the 3.0 power of the clearance height. Effects caused by changing the length and diameter are equivalent. The leakage rate decreases sharply first and then slowly after the length or diameter is larger than a specific value of which the axial length and the half circumference are equal to each other. The performance of the larger size FRV-ERD is much better than the smaller one, and the required clearance is also significantly increased, alleviating machining difficulty to some extent.

Pigment Epithelial-Derived Factor Peptide Regenerated Limbus Serves as Regeneration Source for Limbal Regeneration in Rabbit Limbal Deficiency.

To demonstrate that a 44-amino acid peptide from pigment epithelial-derived factor (PEDF) induces the regeneration of limbal excision wound, and the regenerated limbus can act as the regeneration source for new limbal excisional injuries in rabbit model of limbal deficiency. Half circumference partial limbal excision was followed by PEDF peptide treatment to achieve limbal wound regeneration. Three months later, a second stage half circumference partial limbal excision removed the remaining native limbal tissue followed by PEDF peptide treatment. The structure and function of the regenerated limbus were analyzed at 3 and 6 months. Conjunctivalization was analyzed by impression cytology. Immunohistochemical analysis was performed with antibodies to corneal epithelium-associated keratin 3 (K3), conjunctival epithelium-associated keratin 13 (K13), ΔNp63α, ABCG2, and BrdU. Extensive limbal excision was performed to examine the regeneration potential of the PEDF peptide. Total limbal stem cell deficiency occurred with severe inflammation and conjunctivalization of the limbal wound and adjacent cornea in vehicle control eyes. In PEDF peptide treated eyes, the regenerated limbus prevented fibrovascular invasion and goblet cell migration into the corneal surface. Immunohistochemical staining of the regenerated limbus showed a wide distribution of cells expressing ΔNp63α and ABCG2 as in the native limbus. BrdU labeling assay revealed the presence of slow-cycling cells in the basal layer of the regenerated limbus. The PEDF peptide can heal extensive limbal excisional wounds and sustain ocular surface integrity. The addition of PEDF peptide has the potential to repair limbal excisional wounds with the recovery of normal limbus-like anatomy and function. The PEDF peptide is a potential remedy for extensive limbal injury.

Analysis of ‘free energy’ perpetual motion machine system based on permanent magnets

Claims of “Free Energy” generation using Perpetual Motion Machines (PMM) are usually discounted by the scientific community since PMMs are considered impossible, as a direct corollary of the Law of Conservation of Energy. However for the scientifically inquisitive mind, the urge to distill reasons which make some systems appear as PMMs, remains a factor. Recently a system on permanent magnets has been observed by the author, whose designer claimed that his system can provide ‘free energy’. i.e., the output of the system is greater than the input. This system comprises of eight magnets arranged at equal distances at the rim of a circular disk and a ring magnet at the centre of the disk as shown in Fig. 1. The first magnet at the rim of the circular disk has its north aligned with axis of rotation and facing towards it. The next magnet placed after 1/8th of the circumference is rotated by an angle of 450 around z-axis such that after traveling half circumference the magnet rotates through 1800 as shown in Fig 2. The input is ring magnet which has an inner radius of 31.75 mm and an outer radius of 50.8 mm as shown in Fig. 3. The ring magnet is positioned at an angle between 300400, from the horizontal upper surface of the disk. The lower face of the ring magnet is North Pole and the upper face acts as South Pole or vice versa. In either case the face of the bar magnet facing the ring magnet is such that there is a repulsive force between the two. As the disk rotates initially, the ring magnet is positioned manually by rotating it around it’s z-axis at an angle of 300-400 to an axis parallel to the upper surface of the disk such that at an instant there exists a repulsive force between a pair of bar magnets (separated by 1/2th of the circumference) and the ring magnet. The system has been analyzed using theoretical calculations and simulation with PRO ENGINEER Wildfire 5.0 which shows that it is not a free energy system.

P.07.14 ENDOSCOPIC PIECEMEAL RESECTION OF LARGE COLORECTAL ADENOMAS: A SYSTEMATIC TWO-STEP APPROACH

of lidocain + adrenaline in order to have a local anesthesia and a safe use of APC. In case of extensive lesion (circumferential) we treat one quadrant at the time. Results: In one year we treated 33 male patients (18 HIV positive and 15 HIV negative): one with a circumferentially involment, 7 with half circumference and the others with a median of 3 lesions >5 mm. more than one condyloma >1 cm affecting one or more quadrant on the dentate line. We made a median of 1.5 treatments (range 1–5). In all patients we had a complete eradication of the lesions without sign of recurrence at six months endoscopic control. No complication occurred in our patients. Conclusions: Anorectal condyloma are lesions difficult to treat by endoscopy due to the difficulty to visualize the area and the high sensitivity of this area. Our experience demonstrates that the proposed endoscopic technique can improve the possibilities to treat the majority of these lesions (extensive or not) avoiding surgical approach.

Ten-year results of the Lyon R96-2 randomized trial in distal rectal cancer: Radiation dose escalation to increase organ preservation.

556 Background: This trial was designed to test the role of a radiation dose escalation to increase conservative treatment in distal rectal cancer. The early results showed a significant increase of sphincter saving surgery (Gerard JP et al. J Clin Oncol. 2004;22:2404-2409). We present here clinical results with a 10 years follow up. Methods: Between 199- and 2001, 88 patients were included. Inclusion criteria were: adenocarcinoma of the distal rectal, T2-3 N0 M0 less not exceeding half circumference. Treatment allocation was betweeen 1) external beam radiotherapy(EBRT) (39 Gy/13 fractions/17 days) followed 6 weeks later by surgery. 2) same EBRT with Contact X-Ray 50 Kv boost (CXRT) (90 Gy /3fr/4 weeks). A careful evaluation of the clinical response was performed with digital examination and rigid rectoscopy one week before surgery. Type of surgery was left to the surgeon decision. Results: Median follow-up was 132 months. At 10 years there was no difference between both groups for overall survival and local recurrence but significantly less colostomy in the CXRT group (table). In patient with cCR the cumulated rate of colostomy was 17 % vs 42 % with cPR and 77 % with no response (p=0.014) out of 11 pts in cCR with EBRT + CXRT, 9 were treated with organ preservation (RT alone : 6, transanal local excision 3). Anorectal function was good or excellent in all these 9 patients. Conclusions: After 10 years follow up increased preservation of the anal sphincter due to CXRT has no detrimental effect on local control and survival. These results stress the importance to achieve a clinical complete response (cCR) in order to modify the surgeon decision and to increase the chance of organ preservation with a well preserved function. [Table: see text]

Spin transport properties in double quantum rings connected in series

A new model of metal/semiconductor/metal double-quantum-ring connected in series is proposed and the transport properties in this model are theoretically studied. The results imply that the transmission coefficient shows periodic variations with increasing semiconductor ring size. The effects of the magnetic field and Rashba spin-orbit interaction on the transmission coefficient for two kinds of spin state electrons are different. The number of the transmission coefficient peaks is related to the length ratio between the upper arm and the half circumference of the ring. In addition, the transmission coefficient shows oscillation behavior with enhanced external magnetic field, and the corresponding average value is related to the two leads' relative position.

Effect of non-surgical ocular hypotensive therapy in normal-tension glaucoma

We investigated the effects of the topical ocular hypotensives with or without half circumference argon laser trabeculoplasty (ALT) on intraocular pressure (IOP) of normal-tension glaucoma (NTG) eyes. Seventy-two NTG patients whose pretreatment mean IOP was > or = 15 mmHg at least in one eye were included and one randomly chosen eye from one patient were used for analysis. They were followed for at least 15 months after commencement of the therapy. The mean pretreatment IOP averaged 17.2 +/- 1.6 mmHg (mean +/- standard deviation, n = 72). All eyes were first treated with topical 2% carteolol. In eyes where IOP reduction was considered unsatisfactory, topical 1% pilocarpine or 0.04% dipivefrine was added. In eyes where IOP reduction was still unsatisfactory even with the two medications, half circumference ALT was performed. Mean IOP reduction was 1.5 mmHg in the eyes treated with topical medications alone and 2.5 mmHg in those treated by topical medications plus ALT. The mean outflow pressure reduction was 16 and 26%, respectively. In 40% of the all eyes, satisfactory IOP reduction was obtained by topical medications with or without additional ALT.

Skin incisions for the excision of spherical cutaneous and subcutaneous lesions

Spherical cutaneous and subcutaneous lesions such as sebaceous cysts are often removed via an ellipse, particularly if they are relatively large. Deciding the width of the ellipse can be difficult. We calculated that if the width of the ellipse is one-third of the half circumference, then the wound should close satisfactorily.