Coupled DEM-FDM analyses of the effects of falling rock’s shape and impact angle on response of granular cushion and rock shed

Rock shed is an effective protection measure against rockfall.To investigate the influences of falling rock’s shape and impact angle on the impact effect of the cushioned rock shed,a modeling approach for a rock shed with a cushion layer using PFC-FLAC.The granular cushion is modeled as an aggregate of discrete non-cohesion particles,while the concrete plate and the beam are modeled as zones.The falling rock with different sphericities and impact angles is modeled as a rigid assembly.The numerical model is validated by comparing the simulation results with experimental and numerical results from previous literature.This model is applied to analyze the effects of rock shape and impact angle on the dynamic interaction effects between falling rock and cushioned rock shed,including the impact force,transmitted bottom force,penetration depth,and plate deflection.The numerical results show that the variation in the falling rock’s shape has different effects on the falling rock with different impact angles.These findings could support rock shed design by revealing the limitations of the assumptions in the past research,which may result in unsafe rock sheds for some rockfall cases.

A Procedure for Trisecting an Acute Angle (Method 2)

This paper presents an alternate graphical procedure (Method 2), to that presented in earlier publications entitled, “A Procedure for Trisecting an Acute Angle” and “A Key to Solving the Angle Trisection Problem”. The procedure, when applied to the 30˚ and 60˚ angles that have been “proven” to be nottrisectable and the 45˚ benchmark angle that is known to be trisectable, in each case produced a construction having an identical angular relationship with Archimedes’ Construction, as in Section 2 on THEORY of this paper, where the required trisection angle was found to be one-third of its respective angle (i.e. DE’MA = 1/3 DE’CG). For example, the trisection angle for the 30˚, 45˚ and 60˚ angles were 10.00000˚, 15.00000˚, and 20.00000˚, respectively, and Section 5 on PROOF in this paper. Therefore, based on this identical angular relationship and the numerical results (i.e. to five decimal places), which represent the highest degree of accuracy and precision attainable by The Geometer’s Sketch Pad software, one can only conclude that not only the geometric requirements for arriving at an exact trisection of the 30˚ and 60˚ angle (which have been “proven” to be not-trisectable) have been met, but also, the construction is valid for any arbitrary acute angle, despite theoretical proofs to the contrary by Wantzel, Dudley, and others.

A Simplified Graphical Procedure for Constructing a 10˚or 20˚Angle

This paper presents a simplified graphical procedure for constructing, using an unmarked straightedge and a compass only, a 10˚ to 20˚ angle, which is in other words, trisecting a 30˚ or 60˚ angle. The procedure, when applied to the 30˚ and 60˚ angles that have been “proven” to be not trisectable, produced a construction having the identical angular relationship with Archimedes’ Construction, in which the required trisection angles were found to be 10.00000˚ and 20.00000˚ respectively (i.e. exactly one-third of the given angle or ∠E’MA = 1/3∠E’CG). Based on this identical angular relationship as well as the numerical results obtained, one can only conclude that the geometric requirements for arriving at an exact trisection of the 30˚ or 60˚ angle, and therefore the construction of a 10˚ or 20˚ angle, have been met, notwithstanding the theoretical proofs of Wantzel, Dudley, and others. Thus, the solution to the age-old trisection problem, with respect to these two angles, has been accomplished.

A Key to Solving the Angle Trisection Problem

This paper describes the methodology (or approach) that was key to the solution of the angle trisection problem published earlier in article entitled, “A Procedure For Trisecting An Acute Angle.” It was an approach that required first, designing a working model of a trisector mechanism, second, studying the motion of key elements of the mechanism and third, applying the fundamental principles of kinematics to arrive at the desired results. In presenting these results, since there was no requirement to provide a detailed analysis of the final construction, this information was not included. However, now that the publication is out, it is considered appropriate as well as instructive to explain more fully the mechanism analysis of the trisector in graphical detail, as covered in Section 3 of this paper, that formed the basis of the long sought solution to the age-old Angle Trisection Problem.

骨性Angle′s Ⅲ类错患者正畸手术前后下颌角矢量点位置的变化及意义

目的观察骨性Angle′sⅢ类错患者下颌角矢量点(Gov点)位置变化,并探讨其临床意义。方法取天津地区健康人29例为对照组,接受正手术治疗的骨性Angle′sⅢ类错畸形患者15例为观察组。均拍摄头颅侧位X线片,测量Gov点的座标。结果观察组术前、术后及对照组Gov点横坐标分别为(-4.54±0.51)、(-5.10±0.69)、(-5.02±0.35)cm,纵坐标分别为(-7.76±0.40)、(-7.65±0.57)、(-7.50±0.43)cm,观察组术前Gov点横、纵坐标与术后及对照组比较P均<0.05,观察组术后与对照组Gov点横、纵坐标比较P均>0.05。对照组下颌神经孔与Gov点间距为(1.35±0.16)cm,观察组术前为(1.27±0.19)cm,两组相比P>0.05。结论骨性Angle′sⅢ类错患者Gov点位置向前下移位,正手术后得以纠正。Gov点位置可能与下颌功能状态存在内在联系,可以作为正手术术前制定手术计划及术后评估矫治效果的指标。

Buffon’s Needle Algorithm to Estimate π

Buffon’s needle experiment was originally devised to get the value of π. With the advent of computers, Buffon’s needle algorithm has been used pedagogically as an example of Monte Carlo methods in introduction classes, and there are many Buffon’s needle algorithm implementations available on the internet. However, for the calculation of π, the exact value of π is used in the programs for Buffon’s needle angle sampling, and hence the example is not demonstrated correctly. This brief note presents a random angle sampling algorithm for the Buffon’s needle. We then compare the Buffon’s needle and Hit-and-Miss integration algorithms using Monte Carlo laboriousness comparison, and find that the Hit-and-Miss algorithm is superior.

Modified viscocanalostomy in the Chinese population with open angle glaucoma: a 10-year follow-up results

AIM: To study the long-term efficacy and safety of modified viscocanalostomy in Chinese people with open angle glaucoma(OAG).METHODS: This retrospective study included a total of 100 eyes from 100 Chinese patients with medically uncontrolled OAG. All the patients underwent modified viscocanalostomy with injection of viscoelastic material in the surgically created ostia of Schlemm's canal(SC). The modifications included peeling of the inner wall of SC and the juxtacanalicular meshwork, use of mitomycin C, and loosely suturing the superficial scleral flap. Intraocular pressure(IOP), visual acuity, number of medications, laser goniopuncture data and complications were recorded. The definition of complete(qualified) success was an IOP equal to or lower than 21, 18, 16 mm Hg without(with or without) anti-glaucoma medications. RESULTS: The mean IOP was 33.5±9.9 mm Hg before surgery, 15.2±3.6 mm Hg(mean IOP reduction of 51%) at 5 y after surgery, and 15.6±2.8 mm Hg(mean IOP reduction of 49.9%) at 10 y after surgery(P<0.001). The number of anti-glaucoma medications dropped from 2.39±0.5 preoperatively to 0.47±0.8 at 5 y and 0.67±0.8 at 10 y postoperatively(P<0.001). The follow-up period was 104.5±37.0 mo. The qualified success rate for an IOP of 21, 18 or 16 mm Hg or less was 84% [95% confidence interval(CI): 0.80-0.88], 73%(95%CI: 0.68-0.78), and 59%(95%CI: 0.52-0.66) after 5 y, and 80%(95%CI: 0.76-0.84), 69%(95%CI: 0.64-0.74), 51%(95%CI: 0.44-0.58) after 10 y, respectively. There was a relationship between age, preoperative IOP and success rate(P<0.01, P<0.05). A total of 31 eyes(31.3%)in 31 patients underwent laser goniopuncture, decreasing the IOP from 22.9±4.3 mm Hg to 16.3±2.5 mm Hg(P<0.01). Neither blebitis nor endophthalmitis occurred.CONCLUSION: Modified viscocanalostomy could be performed to lower IOP, decrease multiple anti-glaucoma drops use as well. It's a safe procedure with less complications over 10 y in Chinese individuals with OAG.

Elevated urine formaldehyde in elderly patients with primary open angle glaucoma

AIM：To investigate the risk factor of primary open angle glaucoma（POAG）,which is the leading cause of irreversible blindness worldwide.An abnormally high level of endogenous formaldehyde（FA） has recently been found correlated with cell death and neurodegenerative disease,raising the possibility of a putative correlation of abnormal endogenous FA with POAG.· METHODS：Thirty-four elderly patients with POAG and sixteen healthy controls were enrolled.Glaucomatous visual defects were present at both the functional（visual field） and structural[retinal nerve fiber layer（RNFL）thickness]levels.Morning urine samples were obtained and were analyzed by high-performance liquid chromatography（HPLC） to detect the endogenous FA level in a double blind manner.· RESULTS：Patients with POAG（P 〈0.05） had significantly higher urine FA levels.The urine FA level of patients with severe visual field defects[mean deviation（MD）≥12 dB]was significantly（P〈0.001） greater than that of patients with mild to moderate defects（MD〈12 dB）.By optical coherence tomography（OCT）,the superior and inferior RNFL thickness of POAG group was significantly（P〈0.001） thinner than in controls.Furthermore,the superior and inferior thinning of the RNFL was correlated with the elevation of urine FA concentration.CONCLUSION：Endogenous FA level is positively correlated with the neuronal defects of POAG.

S弯收扩喷管过膨胀状态下流动分离特性研究

为了研究S弯收扩喷管过膨胀状态下的流动分离特性,数值模拟了不同落压比(NPR)下S弯收扩喷管内的流动特征。结果表明:在落压比为2.0时,喷管内发生非对称分离,出现非对称的双“λ”激波结构,喷流整体向上偏转,上侧出现限制性流动分离RSS,下侧出现自由性流动分离FSS,并产生三维分离涡,喷流出现明显的三维效应。随着落压比从高度过膨胀状态下开始增加,喷管下侧保持FSS不变,喷管上侧RSS逐渐向后移动,直至与外界大气相连,转变为FSS,之后随着落压比增加,上下侧分离结构逐渐对称。推力矢量角随着落压比的增加先增加,后在极小的落压比变化范围内快速降低,直至变为0°,之后保持0°不变。

Five-plane lancet needle design for soft PVC phantom tissue cutting

Lancet needle, having three planes at the tip to generate a sharp lancet point, is the most common needle tip geometry and used for medical procedures. This research presents two five-plane lancet needle designs, the five-plane lancet needle with two back bevels （FLN-B） and five-plane lancet needle with two front bevels （FLN-F）, to study the effects of two additional bevel planes on the reduction of soft tissue cutting force. Mathematical models to calculate the inclination angle and rake angle along the cutting edges of FLN-B and FLN-F are developed. By using the grinding process, the prototype FLN-B and FLN-F needles are fabricated. And their inclination and rake angles along the cutting edges are investigated and compared to that of regular lancet needle. Needles insertion tests were conducted on soft PVC phantom which mimics the soft tissue. The initial peak insertion force and steady-state cutting force during needle insertion were identified, and the effect of cutting edge on needle soft tissue cutting force was studied. Compared to lancet needle, FLN-B and FLN-F both have higher inclination and rake angles at the tip cutting edge, could reduce the initial peak needle insertion force and tissue cutting forces, and thus can efficiently cut the soft tissue for medical applications.

Astronomic background of global huge earthquakes at beginning of 21st century

Since the beginning of the 21st century,major earthquakes have frequently occurred worldwide.To explore the impact of astronomical factors on earthquakes,in this study,the statistical analysis method of correlation is used to systematically analyze the effects of astronomical factors,such as solar activity,Earth’s rotation,lunar declination angle,celestial tidal force,and other phenomena on M≥8 global earthquakes at the beginning of the 21st century.With regard to solar activity,this study focuses on the analysis of the 11-year and century cycles of solar activity.The causal relationship of the Earth’s rotation is not obvious in this work and previous works;in contrast,the valley period of the solar activity century cycle may be an important astronomical factor leading to the frequent occurrence of global earthquakes at the beginning of the 21st century.This topic warrants further study.

“S”形固定法在行静脉留置针患者中的应用效果

目的:探讨“S”形固定法在行静脉留置针患者中的应用效果。方法:选取2023年1—12月于锦州医科大学附属第一医院行静脉留置针的患者80例作为研究对象,按照随机数字表法分为对照组和观察组,各40例。对照组采用常规固定方式,观察组采用“S”形固定法。比较两组疼痛程度、手臂活动自由度、皮肤红肿发生率、皮肤红肿严重度。结果:固定后即刻,两组视觉模拟评分法(VAS)评分比较,差异无统计学意义(P>0.05);固定后6 h、12 h、24 h,两组VAS评分低于固定后即刻,且观察组低于对照组,差异有统计学意义(P<0.05)。观察组手臂最大弯曲角度和伸展角度均大于对照组,差异有统计学意义(P<0.001)。观察组皮肤红肿发生率低于对照组,差异有统计学意义(P<0.001)。观察组发生皮肤红肿的患者红肿严重度评分低于对照组,差异有统计学意义(P<0.001)。结论:“S”形固定法在行静脉留置针患者中的应用效果较好,能够减轻患者疼痛,改善手臂活动度,减少及减轻皮肤红肿。

Differential Insertion Depths of Filiform Needle, Concept and Application

In this paper, the background, evolution, basic meaning, clinical application and the detail operating procedures of the differential insertion depth in filiform needle acupuncture were discussed based on the classical expositions of the Yellow Emperor’s Canon of Medicine. It is believed that the differential insertion depth reflects the basic idea of expelling the evil Qi from the body in the application of traditional acupuncture. Since the site of evil invasion has different shades, the position of evil Qi and correct differentiation has become the operation key points of needle insertion. Apart from this, the Yellow Emperor’s Canon of Medicine has further associated the clinical application of filiform needle insertion depth with the seasonal change of Yin and Yang, the body built of the patients, the nature of the diseases, the heat or cold pathogenic factors of the illness, the excess and deficiency of the patient, and the reinforcing and reducing function of acupuncture. These elaborations have greatly enriched the basic content of acupuncture and laid a systematic theoretical foundation of filiform needle operation. The differential insertion depth in acupuncture has its specific meaning, the emphasis of insertion depth of filiform needle with its differentiated clinical implication exemplifies the perceptual thinking features of traditional acupuncture and typical reveals the uniqueness of Chinese civilization.

Automated Detection and Quantification of Prostate Cancer in Needle Biopsies by Digital Image Analysis

Introduction: Triple immunohistochemical (IHC) stains including antibodies specific for alpha-methylacyl-CoA-racemase and basal cell markers have been a valuable aid in accurate identification of prostate carcinoma. However, accurate quantification of minuscule areas of prostate carcinoma in biopsy specimens can often be a challenge. Here we assessed the diagnostic value and quantitative use of automated digital image analysis on triple IHC stained prostate needle biopsies. Methods: Twelve cases of prostate needle biopsy material including 75 needle cores were stained with triple-antibody cocktail (P504S + 34βE12 + p63). Slides were digitally scanned with the APERIO digital image analyzer and evaluated with the GENIE pattern and color recognition digital image analysis that we developed. A slide with known areas of adenocarcinoma, high grade prostatic intraepithelial neoplasia (PIN), benign glands and stroma was used as a training set for the automated digital image analysis platform. Results: Among 75 needle biopsy cores, 19 (25.33%) contained adenocarcinoma by histology. Digital image analysis recognized adenocarcinoma in 95% of these needle biopsies. The average area of the needle biopsy was 7.63 mm2 and overall the average area of tumor was 0.196 mm2. The smallest area of tumor recognized by the program was 0.0022 mm2 (0.0363% of the core) and the largest was 0.62 mm2 (8.17% of the core) among needle core biopsies. False positives resulted from areas of high grade PIN with patchy basal cells. The false negative was caused by uneven AMACR staining in one area of adenocarcinoma. Digital recognition of areas of interest was improved by three successive image analysis training which increased the sensitivity and specificity from 83% and 89% to 90% and 93%, respectively. Conclusions: Digital image analysis in concert with IHC triple staining may be useful for accurate detection and quantitative analysis of small foci of prostatic adenocarcinoma. Defining methods to increase the sensitivity and specificity of quantitative automated digital image analysis will likely evolve as an area of investigation. Future automated digital scanning and innovative pattern and color recognition technologies may open avenues for classifying a variety of prostate lesions.

Correlation of S100A13 and FOXA1 expression with cell cycle and cell invasion in fine needle aspiration thyroid carcinoma tissue

Objective: To study the correlation of S100A13 and FOXA1 expression with cell cycle and cell invasion in fine needle aspiration thyroid carcinoma tissue. Methods: Patients who received ultrasound-guided thyroid nodule fine needle aspiration in Haiyang People's Hospital between April 2015 and February 2017 were selected, and the tissues were divided into malignant thyroid tissue and benign thyroid nodules according to the pathological results after biopsy. The expression of S100A13, FOXA1, cell cycle molecules and cell invasion molecules were measured. Results: S100A13, FOXA1, CDK2, CyclinD1, MCM2, MCM7, SKP2, CLOCK, STAT3, STAT5, N-cadherin, MT1-MMP and ADAM17 mRNA expression in thyroid carcinoma tissue were significantly higher than those in benign thyroid nodule;CDK2, CyclinD1, MCM2, MCM7, SKP2 and CLOCK mRNA expression in thyroid carcinoma tissue with high FOXA1 expression were significantly higher than those in thyroid carcinoma tissue with low FOXA1 expression;STAT3, STAT5, N-cadherin, MT1-MMP and ADAM17 mRNA expression in thyroid carcinoma tissue with high S100A13 expression were significantly higher than those in thyroid cancer tissue with low S100A13 expression. Conclusions: High expression of S100A13 and FOXA1 in thyroid carcinoma can promote cell invasion and cell cycle progression.

On China＇s Economy： A Tentative Research from a Dual Visual Angle

Most economists approach the economy of China from a single visual angle considering it as a special economic modality of transition economy. Based on the analysis from the single visual angle, the paper puts forward a dual visual angle treating China＇s economy as one of both transition and transformation features, and attempts to research it from this dual visual angle.

The Possibility of Angle Trisection （A Compass-Straightedge Construction） Kimuya M Alex

The objective of this paper is to provide a provable solution of the ancient Greek problem of trisecting an arbitrary angle employing only compass and straightedge （ruler）. （Pierre Laurent Wantzel, 1837） obscurely presented a proof based on ideas from Galois field showing that, the solution of angle trisection corresponds to solution of the cubic equation; x3 - 3x - 1 = 0, which is geometrically irreducible [1]. The focus of this work is to show the possibility to solve the trisection of an angle by correcting some flawed methods meant for general construction of angles, and exemplify why the stated trisection impossible proof is not geometrically valid. The revealed proof is based on a concept from the Archimedes proposition of straightedge construction [2, 3].

雷诺数和侧风对S型垂直轴风力机气动特性的影响

相较于工作在郊外良好风场的大型风力机,小型风力机易受城市风环境如低风速、高湍流度以及时变风速风向的影响。采用数值模拟手段研究了雷诺数和来流倾角对小型S型垂直轴风力机气动性能的影响。研究结果表明:S型风力机的气动性能对雷诺数不敏感,功率系数几乎不随雷诺数变化;侧风导致S型风力机的气动性能变差,静扭矩系数和功率系数降低,并且随着侧风来流倾角的增大,气动性能越差,侧风影响的流动机理一方面是来流倾角降低了水平速度分量,另一个方面是竖直速度分量减小了前进叶片的压力差,增加回转叶片的压力差,进一步加剧了气动性能的恶化。

Numerical and Experimental Study on Droplet Spreading Motion after Impingement Considering Dynamic Contact Angle with CCUP （CIP-Combined Unified Procedure） Method

The contact angle is one of important parameters to simulate droplet spreading and impingement phenomena on the surface. In the most numerical research, it is assumed constant value and it is implemented as boundary condition. However, contact angle is changed according to contact line velocity and time. Hence, for accurate simulation, dynamic contact angle which has various values as time elapsed is adopted. In the present study, the numerical analysis is performed on the droplet spreading phenomena considering dynamic contact angle function which is obtained from single droplet spreading experiment on the flat and bare surface. The CIP （cubic interpolated pseudo-particle） method by Yabe is used for analysis of interface between liquid and gas phases. The numerical results considering contact angle function which newly modeled as time and contact angle are compared with numerical results considering Hoffman＇s function and experimental data for range of Weber number which are 4.427 and 11.334. In contrast of numerical result considering Hoffman＇s function, the numerical result shows good agreement with experimental data as time elapsed in contact angle evolution, deformation of droplet spreading radius and height. Indeed, overall, the results display the increasing maximum spreading radius and the decreasing height as Weber numbers increased.