Unicompartmental knee arthroplasty vs high tibial osteotomy for knee osteoarthritis:A comparison of clinical and radiological outcomes

BACKGROUND Unicompartmental knee arthroplasty(UKA)and high tibial osteotomy(HTO)are well-established operative interventions in the treatment of knee osteoarthritis.However,which intervention is more beneficial to patients with knee osteoarthritis remains unknown and a topic of much debate.Simultaneously,there is a paucity of research assessing the relationship between radiographic parameters of knee joint alignment and patient-reported clinical outcomes,preoperatively and following HTO or UKA.AIM To compare UKAs and HTOs as interventions for medial-compartment knee osteoarthritis:Examining differences in clinical outcome and investigating the relationship of joint alignment with respect to this.METHODS This longitudinal observational study assessed a total of 42 patients that had undergone UKA(n=23)and HTO(n=19)to treat medial compartment knee osteoarthritis.Patient-reported outcome measures(PROMs)were collected to evaluate clinical outcome.These included two disease-specific(Knee Injury and Osteoarthritis Outcome Score,Oxford Knee Score)and two generic(EQ-5D-5L,Short Form-12)PROMs.The radiographic parameters of knee alignment assessed were the:Hip-knee-ankle angle,mechanical axis deviation and angle of Mikulicz line.RESULTS Statistical analyses demonstrated significant(P<0.001),preoperative to postoperative,improvements in the PROM scores of both groups.There were,however,no significant inter-group differences in the postoperative PROM scores of the UKA and HTO group.Several significant correlations associated a more distolaterally angled Mikulicz line with worse knee function and overall health preoperatively(P<0.05).Postoperatively,two clusters of significant correlations were observed between the disease-specific PROM scores and knee joint alignment parameters(hip-knee-ankle angle,mechanical axis deviation)within the HTO group;yet no such associations were observed within the UKA group.CONCLUSION UKAs and HTOs are both efficacious operations that provide a comparable degree of clinical benefit to patients with medial compartment knee osteoarthritis.Clinical outcome has a limited association with radiographic parameters of knee joint alignment postoperatively;however,a more distolaterally angled Mikulicz line appears associated with worse knee function/health-related quality of life preoperatively.

Utilization of Bubbles and Oil for Microplastic Capture from Water

The removal of microplastics(MPs)from water using oil has shown early promise;however,incorporation of this technique into a feasible in situ method has yet to be developed.Here,a simple yet effective method of MP capture from water using vegetable oil with bubbles is demonstrated to achieve high removal efficiencies of>98%.Comparisons are made with other methods of agitation,and higher removal efficiencies are observed when bubbles are used.Due to the low agitation provided by the bubbles,the oil layer remains unbroken,meaning that no oil is released into the bulk water phase.In this way,secondary contamination is avoided—unlike membrane filtration,another effective removal method,in which polymer-based membranes can break down due to chemical backwashing and ageing.It is demonstrated that variation in MP size within the micrometer range(50–170 lm)has minor impact on the removal efficiency;however,100%removal is achieved for larger,millimeter-sized MPs(500–5000 lm).Similarly,a high removal efficiency of greater than 99%is achieved in the capture of microfibers.Other factors such as oil volume and water salinity are also investigated and discussed.Based on these results,the proposed method can be introduced into multiple setting types as a passive and continuous method of MP capture.

Coupling of RANS and BEM Solvers for Simulation of Propeller Behind the Hull in Full Appended Model

To design a propeller for ship power plant,the interaction between ship hull and propeller must be taken into account.The main concern is to apply the wake effect of ship stern on the propeller performance.In this paper,a coupled BEM(Boundary Element Method)/RANS(Renolds-Averaged Navier−Stokes)solver is used to simulate propeller behind the hull in the self-propulsion test.The motivation of this work is to develop a practical tool to design marine propulsion system without suffering long computational time.An unsteady boundary element method which is also known as panel method is chosen to estimate the propeller forces.Propeller wakes are treated using a time marching wake alignment method.Also,a RANS code coupled with VoF equation is developed to consider the ship motions and wake field effects in the problem.A coupling algorithm is developed to interchange ship wake field to the potential flow solver and propeller thrust to the RANS code.Based on the difference between hull resistance and the propeller thrust,a PI controller is developed to compute the propeller RPM in every time step.Verification of the solver is carried out using the towing tank test report of a 50 m oceanography research vessel.Wake factor and trust deduction coefficient are estimated numerically.Also,the wake rollup pattern of the propeller in open water is compared with the propeller in real wake field.

Approximately Bi-Similar Symbolic Model for Discretetime Interconnected Switched System

Dear Editor,This letter concerns the development of approximately bi-similar symbolic models for a discrete-time interconnected switched system(DT-ISS).The DT-ISS under consideration is formed by connecting multiple switched systems known as component switched systems(CSSs).Although the problem of constructing approximately bi-similar symbolic models for DT-ISS has been addressed in some literature,the previous works have relied on the assumption that all the subsystems of CSSs are incrementally input-state stable.

Anterior cruciate ligament reconstruction:Effect of graft tunnel position on early to mid-term clinical outcomes

BACKGROUND Patient reported outcome measures(PROMs)can be used to assess knee function following anterior cruciate ligament(ACL)reconstruction.Intra-operatively,femoral and tibial tunnels are created to accommodate the new ACL graft.It is postulated that there is an optimum position and orientation of these tunnels and that outcomes from this procedure are affected by their position.AIM To evaluate the influence of graft tunnel position on early to mid-term clinical outcomes following ACL reconstruction.METHODS Six PROMs were collected following ACL reconstruction which included the Knee Injury and Osteoarthritis Outcome Score(KOOS),International Knee Documentation Committee,Lysholm,Tegner,EuroQol-5 Dimension-5 level,and Short Form 12-item Health Survey.A total of 8 radiological parameters were measured from post-operative X-rays relating to graft tunnel positions.This data was analysed to assess for any correlations between graft tunnel position and postoperative PROMs.RESULTS A total of 87 patients were included in the study with a mean post-operative follow-up of 2.3 years(range 1 to 7 years).Posterior position of tibial tunnel was associated with improved KOOS quality of life(rho=0.43,P=0.002)and EQ-5D VAS(rho=0.36,P=0.010).Anterior position of EndoButton femoral tunnel was associated with an improved EQ-5D index(rho=-0.38,P=0.028).There were no other significant correlations between any of the other radiological parameters and PROM scores.CONCLUSION Overall,graft tunnel position had very little correlation with clinical outcomes following ACL reconstruction.A few(posterior)tibial tunnel and(anterior)EndoButton femoral tunnel measurements were associated with better PROMs.

Optimal scheduling of zero-carbon park considering variational characteristics of hydrogen energy storage systems

Zero-carbon parks have broad prospects in carbon neutralization.As an energy hub,hydrogen energy storage plays an important role in zero-carbon parks.However,the nonlinear characteristics of hydrogen energy storage systems(HESSs)have a significant impact on the system economy.Therefore,considering the variable working condition characteristics of HESSs,a hybrid operation method is proposed for HESS,to support the efficient and economic operation of zero-carbon parks,By analyzing the operating principle of a zero-carbon park with HESS,the system structure framework and variable condition linearization model of the equipment in HESS are established.Moreover,considering the energy output characteristics of hydrogen energy storage equipment under variable working conditions,a multimodule hybrid operation strategy is proposed for electrolytic and fuel cells,effectively meeting the thermoelectric load demand of zero-carbon parks in different scenarios.Finally,the economy of the proposed hybrid operation strategy was verified in typical scenarios,using a zero-carbon park embedded with a HESS.

A symmetric substructuring method for analyzing the natural frequencies of conical origami structures

Conical origami structures are characterized by their substantial out-of-plane stiffness and energy-absorptioncapacity.Previous investigations have commonly focused on the static characteristics of these lightweight struc-tures.However,the efficient analysis of the natural vibrations of these structures is pivotal for designing conicalorigami structures with programmable stiffness and mass.In this paper,we propose a novel method to analyzethe natural vibrations of such structures by combining a symmetric substructuring method(SSM)and a gener-alized eigenvalue analysis.SSM exploits the inherent symmetry of the structure to decompose it into a finiteset of repetitive substructures.In doing so,we reduce the dimensions of matrices and improve computationalefficiency by adopting the stiffness and mass matrices of the substructures in the generalized eigenvalue analysis.Finite element simulations of pin-jointed models are used to validate the computational results of the proposedapproach.Moreover,the parametric analysis of the structures demonstrates the influences of the number of seg-ments along the circumference and the radius of the cone on the structural mass and natural frequencies of thestructures.Furthermore,we present a comparison between six-fold and four-fold conical origami structures anddiscuss the influence of various geometric parameters on their natural frequencies.This study provides a strategyfor efficiently analyzing the natural vibration of symmetric origami structures and has the potential to contributeto the efficient design and customization of origami metastructures with programmable stiffness.

Application of Predictive Model for Efficient Cassava (Manihot esculenta Crantz) Yield in the Face of Climate Variability in Enugu State, Nigeria

Climate variability as occasioned by conditions such as extreme rainfall and temperature, rainfall cessation, and irregular temperatures has considerable impact on crop yield and food security. This study develops a predictive model for cassava yield (Manihot esculenta Crantz) amidst climate variability in rainfed zone of Enugu State, Nigeria. This study utilized data of climate variables and tonnage of cassava yield spanning from 1971 to 2012;as well as information from a questionnaire and focus group discussion from farmers across two seasons in 2023 respectively. Regression analysis was employed to develop the predictive model equation for seasonal climate variability and cassava yield. The rainfall and temperature anomalies, decadal change in trend of cassava yield and opinion of farmers on changes in rainfall season were also computed in the study. The result shows the following relationship between cassava and all the climatic variables: R2 = 0.939;P = 0.00514;Cassava and key climatic variables: R2 = 0.560;P = 0.007. The result implies that seasonal rainfall, temperature, relative humidity, sunshine hours and radiation parameters are key climatic variables in cassava production. This is supported by computed rainfall and temperature anomalies which range from −478.5 to 517.8 mm as well as −1.2˚C to 2.3˚C over the years. The questionnaire and focus group identified that farmers experienced at one time or another, late onset of rain, early onset of rain or rainfall cessation over the years. The farmers are not particularly sure of rainfall and temperature characteristics at any point in time. The implication of the result of this study is that rainfall and temperature parameters determine the farming season and quantity of productivity. Hence, there is urgent need to address the situation through effective and quality weather forecasting network which will help stem food insecurity in the study area and Nigeria at large. The study made recommendations such as a comprehensive early warning system on climate variability incidence which can be communicated to local farmers by agro-meteorological extension officers, research on crops that can grow with little or no rain, planning irrigation scheme, and improving tree planting culture in the study area.

Enhancing Hygrothermal Performance in Multi-Zone Constructions through Phase Change Material Integration

As buildings evolve to meet the challenges of energy efficiency and indoor comfort,phase change materials(PCM)emerge as a promising solution due to their ability to store and release latent heat.This paper explores the transformative impact of incorporating PCMon the hygrothermal dynamics of multi-zone constructions.The study focuses on analyzing heat transfer,particularly through thermal conduction,in a wall containing PCM.A novel approach was proposed,wherein the studied system(sensitive balance)interacts directly with a latent balance to realistically define the behavior of specific humidity and mass flow rates.In addition,a numerical model implemented in MATLAB software has been developed to investigate the effect of integrating PCM on the hygrothermal balances inside the building.The obtained results indicate a consistent response in internal temperatures,specific humidity,and mass flow rates,with temperature differences ranging from 5℃to 13℃and a maximum phase shift of 13 h.In addition,the findings provided valuable insights into optimizing the design and performance of multi-zone constructions,offering a sustainable pathway for enhancing building resilience and occupant well-being.

Optimizing Sustainability:Exergoenvironmental Analysis of a Multi-Effect Distillation with Thermal Vapor Compression System for Seawater Desalination

Seawater desalination stands as an increasingly indispensable solution to address global water scarcity issues.This study conducts a thorough exergoenvironmental analysis of a multi-effect distillation with thermal vapor compression(MED-TVC)system,a highly promising desalination technology.The MED-TVC system presents an energy-efficient approach to desalination by harnessing waste heat sources and incorporating thermal vapor compression.The primary objective of this research is to assess the system’s thermodynamic efficiency and environmental impact,considering both energy and exergy aspects.The investigation delves into the intricacies of energy and exergy losses within the MED-TVC process,providing a holistic understanding of its performance.By scrutinizing the distribution and sources of exergy destruction,the study identifies specific areas for enhancement in the system’s design and operation,thereby elevating its overall sustainability.Moreover,the exergoenvironmental analysis quantifies the environmental impact,offering vital insights into the sustainability of seawater desalination technologies.The results underscore the significance of every component in the MED-TVC system for its exergoenvironmental performance.Notably,the thermal vapor compressor emerges as pivotal due to its direct impact on energy efficiency,exergy losses,and the environmental footprint of the process.Consequently,optimizing this particular component becomes imperative for achieving a more sustainable and efficient desalination system.

Exergy Analysis of a Solar Vapor Compression Refrigeration System Using R1234ze(E)as an Environmentally Friendly Replacement of R134a

Refrigeration plays a significant role across various aspects of human life and consumes substantial amounts of electrical energy.The rapid advancement of green cooling technology presents numerous solar-powered refrigeration systems as viable alternatives to traditional refrigeration equipment.Exergy analysis is a key in identifying actual thermodynamic losses and improving the environmental and economic efficiency of refrigeration systems.In this study exergy analyze has been conducted for a solar-powered vapor compression refrigeration(SP-VCR)system in the region of Gharda颽(Southern Algeria)utilizing R1234ze(E)fluid as an eco-friendly substitute for R134a refrigerant.A MATLAB-based numerical model was developed to evaluate losses in different system components and the exergy efficiency of the SP-VCR system.Furthermore,a parametric study was carriedout to analyze the impact of various operating conditions on the system’s exergy destruction and efficiency.The obtained results revealed that,for both refrigerants,the compressor exhibited the highest exergy destruction,followed by the condenser,expansion valve,and evaporator.However,the system using R1234ze(E)demonstrated lower irreversibility compared to that using R134a refrigerant.The improvements made with R1234ze are 71.95%for the compressor,39.13%for the condenser,15.38%for the expansion valve,5%for the evaporator,and 54.76%for the overall system,which confirm the potential of R1234ze(E)as a promising alternative to R134a for cooling applications.

Application of Machine Learning for Flood Prediction and Evaluation in Southern Nigeria

This study explored the application of machine learning techniques for flood prediction and analysis in southern Nigeria. Machine learning is an artificial intelligence technique that uses computer-based instructions to analyze and transform data into useful information to enable systems to make predictions. Traditional methods of flood prediction and analysis often fall short of providing accurate and timely information for effective disaster management. More so, numerical forecasting of flood disasters in the 19th century is not very accurate due to its inability to simplify complex atmospheric dynamics into simple equations. Here, we used Machine learning (ML) techniques including Random Forest (RF), Logistic Regression (LR), Naïve Bayes (NB), Support Vector Machine (SVM), and Neural Networks (NN) to model the complex physical processes that cause floods. The dataset contains 59 cases with the goal feature “Event-Type”, including 39 cases of floods and 20 cases of flood/rainstorms. Based on comparison of assessment metrics from models created using historical records, the result shows that NB performed better than all other techniques, followed by RF. The developed model can be used to predict the frequency of flood incidents. The majority of flood scenarios demonstrate that the event poses a significant risk to people’s lives. Therefore, each of the emergency response elements requires adequate knowledge of the flood incidences, continuous early warning service and accurate prediction model. This study can expand knowledge and research on flood predictive modeling in vulnerable areas to inform effective and sustainable contingency planning, policy, and management actions on flood disaster incidents, especially in other technologically underdeveloped settings.

Major challenges and recent advances in characterizing biomass thermochemical reactions

Thermochemical conversions are pathways for biomass utilization to produce various value-added energy and chemical products. For the development of novel thermochemical conversion technologies, an accurate understanding of the reaction performance and kinetics is essential. Given the diversity of the thermal analysis techniques, it is necessary to understand the features and limitations of the reactors, ensuring that the selected thermal analysis reactor meets the specific need for reaction characterization. This paper provides a critical overview of the thermal analysis reactors based on the following perspectives: 1) gas flow conditions in the reactor, 2) particle’s external and internal heat and mass transfer limitations, 3) heating rate, 4) temperature distribution, 5) nascent char production and reaction, 6) liquid feeding and atomization, 7) simultaneous sampling and analyzing of bed materials, and 8) reacting atmosphere change. Finally, prospects and future research directions in the development of analysis techniques are proposed.

即时／准即时u-v覆盖的光学综合孔径成像分析

介绍了即时/准即时u-v覆盖的光学综合孔径成像技术实时/准实时观测的优点,并以LBT为实例进行了成像分析.对LBT采用快速傅里叶变换、卷积与反卷积算法获得系统的点扩展函数(PSF)与光学传递函数(OTF);探讨了全局传递函数及其对成像效果的影响,说明了即时/准即时u-v覆盖成像特性;用实验仿真的方法验证了全局传递函数在满足准即时u-v覆盖成像的要求情况下能够对天体目标进行较好的图像恢复.

船舶自主避碰的慎思型轨迹规划

基于快速扩展随机树(RRT)算法,提出一种适用于船舶自主避碰的慎思型轨迹规划(DTP)算法,能够耦合处理静态障碍物约束、船舶操纵性约束、轨迹最优性等限制条件,在两个长程路径点之间完成全局轨迹规划,以保证规划轨迹的可行性、完备性和最优性.通过一条案例三体船的自主避碰仿真及航行试验,从多方面验证了所提DTP算法的有效性、优越性和稳定性,对研究船舶自主避碰系统及其应用前景具有重要的意义.

土壤水资源及其评价方法研究

阐述了土壤水资源的定义及研究土壤水资源的重要意义 ,分析了土壤水资源的结构 ,提出了土壤水资源评价方法 ,重点研究了可更新的土壤水资源和可开发利用的土壤水资源 ,并指出土壤水资源的开发利用是保证农业可持续发展和缓解我国水资源问题的重要手段之一。

脉冲涡流阵列缺陷成像检测技术

脉冲涡流阵列系统具有大面积、快速检测的优点,可用于金属表面裂纹的自动在线检测。在无损检测领域,应用成像技术可以直观地观测到被检测物体的缺陷位置及大小,提高检测人员的工作效率,促进无损检测技术的应用普及。设计了一套脉冲涡流阵列检测系统,包括脉冲涡流阵列探头。应用该系统对标准铝合金试件的缺陷进行了初步的成像处理,给出了标准铝合金试块缺陷成像检测结果,并指出今后的工作方向。

沙尘PM_(10)质量浓度与气温的关系初探

利用甘肃民勤自动气象站观测的2004～2006年夏季的5 min一次的气温与沙尘PM10浓度资料,通过将数据分为实验组与对照组,研究了气温与沙尘天气之间的统计关系。个例显示,气温与沙尘PM10浓度之间存在降温、升温和混合型3种对应关系。实验组统计分析表明,气温及其变化(每5min间隔气温变化绝对值和每24 h间隔气温变化绝对值)与沙尘PM10浓度及其变化呈现出非常显著的正相关关系;沙尘暴天气下日平均气温变化与相应沙尘PM10浓度变化呈显著负相关。对照组结果表明,实验组统计关系是非常显著的。

Pheasants in sacred and other forests in western Sichuan: their cultural conservation

Buddhism and local cultural traditions have long protected wildlife species and their habitats in Tibetan-dominated areas of western Sichuan. In Daocheng County, the White Eared-pheasant (Crossoptilon crossoptilon) has been afforded special protection by local people because it is conspicuous and white, a color with special symbolism for Buddhists. This and other cultural reasons have led to pheasants and forests benefiting in some areas. Pheasants were found during surveys between January 2003 and June 2004 in forests with varying degrees of local (non-formal) protection. However, there were significant signs that these traditional attitudes were changing in the face of three particular pressures brought to bear by better roads, improving access to and from the rest of China. The first was the development of a significant local demand for the Chinese caterpillar fungus (Cordyceps sinesis), which is much sought after throughout East Asia and mushrooms. Second, and more recent, is a dramatic increase in tourism from major Chinese cities, bringing non-Tibetan values into Daocheng County and changing the local attitudes to all animals. And then, there is a rise in income of the local population, resulting in a higher timber demand for building big houses, which impact all wildlife in the forest, but local attitudes to sacred forests have been retained so far in spite of this increased timber demand. Lessons should be learnt from the impact that unregulated tourism at Chonggu monastery, the most visited area in the county, has on the surrounding forests so that other sacred and non-sacred forests can best be protected for the long term. The alternative is that several Tibetan Plateau Galliformes, currently considered non-threatened because of their extensive distribution in a remote area, cannot be guaranteed such a healthy future.

美国游艇安全事故分析及对中国游艇管理的借鉴

通过对近年来美国游艇事故原因的分析,总结事故致因及发生的规律;结合中国近海水域游艇活动的实际情况,探讨游艇管理的方法,旨在进一步提高游艇活动安全,为相关管理部门提供借鉴和参考。