Early Treatment Outcome of Humeral Shaft Fracture Non-Union in Adults: Comparative Study of Plating versus Interlocking Nailing

Background: Fractures of humeral shaft in adults are common injuries. Humeral shafts non-union either from late presentation after initial treatment by traditional bone setters or failed non-operative orthodox care is a major problem in this part of the world. This non-union is a major treatment challenge with increased cost of care and morbidity in this part of the world. Humeral shaft non-union can be treated with locked intra-medullary nailing (LIMN) or dynamic compression plating (DCP). Study on comparison of these methods of fixation in this part of the world is scarce in literature search, hence the reason for this study. Objective: The objectives of this study are: (1) to compare early clinical outcome following fixation of humeral shaft fracture nonunion with DCP versus LIMN;(2) to compare the time of radiologic fracture union of DCP with LIMN;(3) to compare complications following fixation of humeral shaft fracture nonunion with DCP versus LIMN. Patients and Methods: This was a randomized control study done for 2 years in which fifty adult patients with humeral shaft non-union were recruited. The patients were grouped into 2 (P = DCP & N = LIMN). Forty five of the patients completed the follow up periods of the study and then analyzed. The P group had ORIF with DCP while the N group had ORIF with LIMN. Both groups had grafting with cancellous bones. Each patient was followed up for a period of 6 months at the time which radiographic union is expected. Any patient without clinical and/or radiographic evidence of union after six months of surgery was diagnosed as having recurrent non-union. The data generated was analyzed using SPSS Version 23. The results were presented in charts and tables. The paired t-test was used while considering p value Result: Forty five patients completed follow up. There was a male preponderance (4:1), right humerus predominated (3:2). Motor vehicular accidents were the commonest cause of the fractures (62%). Most non-union fractures occurred at the level of the middle 3rd of the humeral shaft (60%). Failed TBS treatment was the commonest indication for the osteosynthesis (71%). More patients had plating (53%) compared to 47% who had LIMN. Most patients (93.4%) had union between 3 to 6 months irrespective of fixation type with no significant statistical difference between the union rate of DCP and LIMN (p value 0.06) with similar functional outcome and complication rates irrespective of the type of fixation. Conclusion: This study showed that the success rates in term of fracture union, outcome functional grades and complication rates were not directly dependent on the types of the fixation: plating or locked intra-medullary nailing.

ON THE EXISTENCE OF LOCAL CLASSICAL SOLUTION FOR A CLASS OF ONE-DIMENSIONAL COMPRESSIBLE NON-NEWTONIAN FLUIDS

In this paper, the aim is to establish the local existence of classical solutions for a class of compressible non-Newtonian fluids with vacuum in one-dimensional bounded intervals, under the assumption that the data satisfies a natural compatibility condition. For the results, the initial density does not need to be bounded below away from zero.

One-dimensional large-strain consolidation of soft clay with non-Darcian flow and nonlinear compression and permeability of soil

Geometrical nonlinearity of the soft soil and the deviation of water flow in the soft clay from Darcy's law have been well recognized in practice. However, the theory of consolidation, which can account for both the geometrical nonlinearity and the non-Darcian flow, has not been reported so far. In this contribution, a model for the consolidation of soft clay which can allow for these two factors simultaneously is proposed. Utilizing the finite difference method, the numerical model for this problem is developed. With the numerical model, the effects of the geometrical nonlinearity and the non-Darcian flow on the consolidation of the soft soil are investigated. The results show that when the self-weight stress is calculated by the same method, the rate of the non-Darcian consolidation for the large-strain case is larger than that for the small-strain case, but the difference between them is limited. However, the difference between the consolidation rates caused by the non-Darcian and Darcian flows is significant. Therefore, when the geometrical nonlinearity of the soft clay is considered in calculating the consolidation settlement, due to the complexity of the large-strain assumption, the small-strain assumption can be used to replace it if the self-weight stress for the small-strain assumption is calculated by considering its sedimentation. However, due to the aforementioned large difference between the consolidation rates with consideration of the non-Darcian flow in soft clay or not, it is better to consider the non-Darcian flow law for both the small and large stain assumptions.

Buckling of un—stiffened cylindrical shell under non—uniform axial compressive stress

This paper provides a review of recent research advances and trends in the area of stability of unstiffened circular cylindrical shells subjected to general non-uniform axial compressive stresses.Only the more important and interesting aspects of the research,judged from a personal viewpoint,are discussed.They can be crudely classified into four categories:(1) shells subjected to non-uniform loads;(2) shells on discrete supports;(3) shells with intended cutouts/holes;and (4) shells with non-uniform settlements.

STABILITY OF BOUNDARY LAYER TO AN OUTFLOW PROBLEM FOR A COMPRESSIBLE NON-NEWTONIAN FLUID IN THE HALF SPACE

This paper investigates the large-time behavior of solutions to an outflow problem for a compressible non-Newtonian fluid in a half space. The main concern is to analyze the phenomena that happens when the compressible non-Newtonian fluid blows out through the boundary. Based on the existence of the stationary solution, it is proved that there exists a boundary layer(i.e., the stationary solution) to the outflow problem and the boundary layer is nonlinearly stable under small initial perturbation.

Impact of prehospital medical evacuation (MEDEVAC) transport time on combat mortality in patients with noncompressible torso injury and traumatic amputations: a retrospective study

Background: In combat operations, patients with traumatic injuries require expeditious evacuation to improve survival. Studies have shown that long transport times are associated with increased morbidity and mortality. Limited data exist on the influence of transport time on patient outcomes with specific injury types. The objective of this study was to determine the impact of the duration of time from the initial request for medical evacuation to arrival at a medical treatment facility on morbidity and mortality in casualties with traumatic extremity amputation and noncompressible torso injury(NCTI).Methods: We completed a retrospective review of MEDEVAC patient care records for United States military personnel who sustained traumatic amputations and NCTI during Operation Enduring Freedom between January 2011 and March 2014. We grouped patients as traumatic amputation and NCTI(AMP+NCTI), traumatic amputation only(AMP),and neither AMP nor NCTI(Non-AMP/NCTI). Analysis was performed using chi-squared tests, Fisher's exact tests,Cochran-Armitage Trend tests, Shapiro-Wilks tests, Wilcoxon and Kruskal-Wallis techniques and Cox proportional hazards regression modeling.Results: We reviewed 1267 records, of which 669 had an injury severity score(ISS) of 10 or greater and were included in the analysis. In the study population, 15.5% sustained only amputation injuries(n=104, AMP only), 10.8% sustained amputation and NCTI(n=72, AMP+NCTI), and 73.7% did not sustain either an amputation or an NCTI(n=493,Non-AMP/NCTI). AMP+NCTI had the highest mortality(16.7%) with transport time greater than 60 min. While the AMP+NCTI group had decreasing survival with longer transport times, AMP and Non-AMP/NCTI did not exhibit the same trend.Conclusions: A decreased transport time from the point of injury to a medical treatment facility was associated with decreased mortality in patients who suffered a combination of amputation injury and NCTI. No significant association between transport time and outcomes was found in patients who did not sustain NCTI. Priority for rapid evacuation of combat casualties should be given to those with NCTI.

Experimental study on cracking behaviour of moulded gypsum containing two non-parallel overlapping flaws under uniaxial compression

Failure of rock mass that is subjected to compressive loads occurs from initiation, propagation, and linkage of new cracks from preexisting fissures. Our research investigates the cracking behaviour and coalescence process in a brittle material with two non-parallel overlapping flaws using a high-speed camera. The coalescence tensile crack and tensile wing cracks were the first cracks to occur from the preexisting flaws. The initiation stresses of the primary cracks at the two tips of each flaw were simultaneous and decreased with reduced flaw inclination angle. The following types of coalescence cracks were identified between the flaws: primary tensile coalescence crack, tensile crack linkage, shear crack linkage, mixed tensile-shear crack, and indirect crack coalescence. Coalescence through tensile linkage occurred mostly at pre-peak stress. In contrast, coalescence through shear or mixed tensile-shear cracks occurred at higher stress. Overall, this study indicates that the geometry of preexisting flaws affect crack initiation and coalescence behaviour.

TIME PERIODIC SOLUTIONS OF NON-ISENTROPIC COMPRESSIBLE MAGNETOHYDRODYNAMIC SYSTEM

In this paper, we study the non-isentropic compressible magnetohydrodynamic system with a time periodic external force in R^n. Under the condition that the optimal time decay rates are obtained by spectral analysis, we show that the existence, uniqueness and time-asymptotic stability of time periodic solutions when the space dimension n 〉 5. Our proof is based on a combination of the energy method and the contraction mapping theorem.

LOW MACH NUMBER LIMIT OF A COMPRESSIBLE NON-ISOTHERMAL NEMATIC LIQUID CRYSTALS MODEL

In this paper, we study the low Mach number limit of a compressible nonisothermal model for nematic liquid crystals in a bounded domain. We establish the uniform estimates with respect to the Mach number, and thus prove the convergence to the solution of the incompressible model for nematic liquid crystals.

Dust Acoustic Compressive Waves in a Warm Dusty Plasma Having Non-Thermal Ions and Non-Isothermal Electrons

In this article an investigation is presented on the properties of dust acoustic（DA）compressive solitary wave propagation in an adiabatic dusty plasma,including the effect of nonthermal positive and negative ions and non-isothermal electrons.The reductive perturbation method has been employed to derive the lower degree modified Kadomtsev-Petviashivili（mK-P）,3D Schamel-Korteweg-de-Vries equation or modified Kadomtsev-Petviashivili（mK-P） equations for dust acoustic solitary waves in a homogeneous,unmagnetized and collisionless plasma whose constituents are non-isothermal electrons,singly charged positive and negative non-thermal ions and massive charged dust particles.The stationary analytical solutions of the lower degree mK-P and mK-P equations are numerically analyzed,where the effect of various dusty plasma constituents on DA solitary wave propagation is taken into account.It is observed that both the ions in dusty plasma play a key role in the formation of DA compressive solitary waves,and also the ion concentration and non-isothermal electrons control the transformation of the compressive potentials of the waves.

MRI Contribution in the Diagnosis of Non-Traumatic Medular Compressions at the Mali Hospital of about 179 Cases

Slow spinal compressions are due to the development of an expansive process in the spinal canal. It is a very common pathology, the diagnosis of which is mainly clinical. However, magnetic resonance imaging occupies an essential place in the site diagnosis and etiological research in the management. Non-traumatic spinal cord compression is a diagnostic and therapeutic emergency, requiring early and appropriate management. MRI is the benchmark imaging examination for this pathology. No similar previous MRI study in Mali. We undertook this work with the aim to determine the place of MRI in the diagnosis of spinal cord compressions in Mali hospital. Method and Patients: This was a descriptive retrospective study, carried out at the hospital’s medical imaging department from January 1, 2017 to December 31, 2018 (02 years). It involved all patients, regardless of sex and age, sent for an MRI examination of the spine, and in whom spinal cord compression was diagnosed. We used a 0.35T low-field MRI machine with solid-state antennas. Results: We collected 179 cases of spinal cord compression MRI out of 585 spinal MRI performed, (frequency of 30.59%). The average age was 53.5 years with a male predominance (sex ratio 3.7). Motor disorders were the most common reason for examination (41%). We used the T1 T2 sagittal and T2 axial sequences. IV injection of gadolinium was performed in 48% of patients. The topographic lesions were: cervical (54.7%), thoracic (31.3%) and several segments (9.5%). The lesions concerned the compartments: extradural (79.3%), intradural (4.5%), and intramedullary (16.2%). The processes were degenerative (57.5%). tumorous (29.6%), infectious (12.3%) and vascular (0.6%). Conclusion: MRI is the benchmark imaging test for the management of non-traumatic spinal cord injury. Myelo-CT can be an alternative in the absence or in case of MRI contraindication.

GLOBAL EXISTENCE OF STRONG SOLUTIONS OF NAVIER-STOKES EQUATIONS WITH NON-NEWTONIAN POTENTIAL FOR ONE-DIMENSIONAL ISENTROPIC COMPRESSIBLE FLUIDS

The aims of this paper are to discuss global existence and uniqueness of strong solution for a class of isentropic compressible navier-Stokes equations with non-Newtonian in one-dimensional bounded intervals. We prove two global existence results on strong solutions of isentropic compressible Navier-Stokes equations. The first result shows only the existence. And the second one shows the existence and uniqueness result based on the first result, but the uniqueness requires some compatibility condition.

Estimation of Non-WSSUS Channel for OFDM Systems in High Speed Railway Environment Using Compressive Sensing

Non Wide Sense Stationary Uncorrelated Scattering (Non-WSSUS) is one of characteristics for high-speed railway wireless channels. In this paper, estimation of Non-WSSUS Channel for OFDM Systems is considered by using Compressive Sensing (CS) method. Given sufficiently wide transmission bandwidth, wireless channels encountered here tend to exhibit a sparse multipath structure. Then a sparse Non-WSSUS channel estimation approach is proposed based on the delay-Doppler-spread function representation of the channel. This approach includes two steps. First, the delay-Doppler-spread function is estimated by the Compressive Sensing (CS) method utilizing the delay-Doppler basis. Then, the channel is tracked by a reduced order Kalman filter in the sparse delay-Doppler domain, and then estimated sequentially. Simulation results under LTE-R standard demonstrate that the proposed algorithm significantly improves the performance of channel estimation, comparing with the conventional Least Square (LS) and regular CS methods.

Implementation of Non-Newtonian Fluid Properties for Compressible Multiphase Flows in OpenFOAM

The paper presents the implementation of non-Newtonian fluid properties for compressible multiphase solver in the open source framework OpenFOAM. The transport models for Power Law, Cross Power Law, Casson, Bird-Carreau and Herschel-Bulkley fluids were included in the thermophysical model library. Appropriate non-Newtonian liquids have been chosen from literature, and pressure driven test simulations are carried out. Therefore, the solver compressibleInterFoam is used to compute air-liquid mixture flows over a backward facing step. A validation of the novel models has been performed by means of a sample-based comparison of the strain rate viscosity relation. The theoretical rheological properties of the selected liquids agree well with the results of the simulated data.

Compressed sensing and Otsu's method based binary CT image reconstruction technique in non-destructive detection

This paper tries to address the problem of binary CT image reconstruction in non-destructive detection with an algorithm based on compressed sensing(CS) and Otsu's method, which could reconstruct binary CT image of test object from incomplete detection data. According to binary CT image characteristics, we employ Splitbregman method based on L1/2regularization to solve piecewise constant region reconstruction. To improve the reconstructed image quality from incomplete detection data, we utilize a priori knowledge and Otsu's method as the optimization constraint. In our study, we make numerical simulation to investigate our proposed method,and compare reconstructed results from different reconstruction methods. Finally, the experimental results demonstrate that the proposed method could effectively reduce noise and suppress artifacts, and reconstruct high-quality binary image from incomplete detection data.

复合型固化剂固化黏土强度试验研究

为研究固化剂-黏土的强度特性,养护7 d后,对不同水泥含量的固化土采用单轴无侧限压缩试验。试件处于干燥和泡水两种状态,测得黏土、固化剂掺入黏土、固化剂与水玻璃掺入黏土三种情况下试件单轴无侧限抗压强度。分析黏土名义黏聚力c′的演化特征。试验结果表明:其他条件不变,随着水泥含量的增大,试件强度先减小后增大,当水泥含量(质量分数)为7%时,试件强度最低;加入固化剂后的泡水试件强度随着水泥含量的增大而增大;加入固化剂能显著提高试件的抗压强度;加入固化剂和水玻璃,试件强度与单独加入固化剂相差不大;名义黏聚力c′与无侧限单轴抗压强度变化规律一致。

超高次谐波测量方法研究进展

随着“双高”特征日益显著,电网中2 kHz~150 kHz频率范围的超高次谐波发射不断增多,由其引发的新型电能质量问题和故障等也越来越多。文章梳理和归纳了已有的超高次谐波测量方法,包括IEC国际标准推荐的3种候选方法,以及近年来多国专家学者研究提出的超高次谐波测量方法,包括子采样、压缩感知和小波包分解等非参数化方法,以及旋转不变子空间和矩阵束等参数化方法;并着重阐述了这些测量方法的原理、技术实现特点、性能指标、优势和不足,以及若干测量方法不断向着高分辨率、高准确性进步的发展历程,并指出了超高次谐波测量方法未来研究的新任务和新方向。

等效非均匀荷载条件下梯形截面岩石力学特性试验研究

基于巷道开挖过程中围岩应力转移分布特点,着重探究非均匀荷载下岩体变形规律。提出了新的岩石力学试验方法,该方法根据岩石应力–应变曲线,加工出特定的梯形截面试件及相应的刚性垫片,以实现单轴压缩时的轴向荷载非均匀分布。计算了梯形截面试件压缩时荷载分布与截面高度的关系,并对试验条件下的试件应力分布与岩石状态分区进行讨论,在右侧面高度为75 mm时试件破坏前左侧面处于塑性变形阶段,在右侧面高度为85 mm时试件破坏前左侧面仍处于弹性变形阶段。得到了非均匀荷载压缩条件下单一完整岩体的变形特性;梯形截面砂岩破坏前有明显的分区,各点位塑性硬化程度不一致,S85试件点位3右侧处塑性硬化程度最大,S75试件点位2右侧处塑性硬化程度最大。试验结果表明,非均匀荷载压缩条件下的岩石呈非线性变形特征;同时,岩石局部的损伤会加快附近岩石的塑性软化。提出了非均匀荷载条件下不同竖向截面内轴向应变差会引起附加切应力,附加切应力在中性面上、下方向相反,大小与应变变化率成正相关。在附加切应力作用下,岩石单元最大剪应力平面角度增大,试件破坏形态由原本对“核”形态转变为沿着斜面倾向拉长的相对棱台状。

碱激发矿渣混凝土密实性超声无损检测法及其影响因素

研究了碱激发矿渣混凝土水胶比、模数、碱当量及粗骨料含量对其抗压强度、超声波速的影响,并通过分析混凝土配合比参数与密度、弹性模量、孔隙率之间的关系来揭示超声波速的变化机理。结果表明:不同配合比参数的碱激发矿渣混凝土超声波速与弹性模量成正比,与密度、孔隙率成反比,在超声无损检测过程中可将碱激发矿渣混凝土近似作为均质性实体材料进行建模计算,发现其超声波速与抗压强度呈线性关系。基于理论分析与试验结果建立了碱激发矿渣混凝土的密实性计算模型,可以为检测碱激发矿渣混凝土密实性作参考。

基于邻接比特压缩表的频繁闭项集挖掘算法

频繁闭项集(Frequent Closed Items,FCI)是一种表示事物之间关联关系的有效方式,它能克服频繁项集(Frequent Items,FI)信息冗余的缺点。FCI挖掘算法研究旨在以更优的时空效率,在原始数据集中找到所有的FCI。相关研究成果重在关注时间效率的提升,但空间效率欠佳。提出一种高空间压缩率数据结构——邻接比特压缩表(Compressed Adjacency Byte table,Cab-table),将项集与交易集压缩到剔除全部0之后的比特表中,使空间高度压缩。基于此数据结构的频繁闭项集挖掘算法(Cab-Miner),采用运算栈与检索栈来实现非递归方式的频繁闭项集挖掘,相较于之前普遍采用递归方式的算法,在理论上可使空间占用率由O(L*N+M)降为O(3N)。基于公开数据集与真实数据集的实验表明,上述算法在原始数据集压缩,以及运算内存消耗上,都有较优的表现,尤其在处理真实数据集时,空间表现极佳。另外在某些属性的数据集上也表现出优越的时间效率。