tensiometer

张力计
  • 文章类型: Journal Article
    周围神经损伤是反向肩关节成形术(RSA)后公认的并发症,主要在臂丛神经及其近端分支的水平进行了研究。然而,RSA对远端周围神经的影响以及肘部和腕部位置的影响尚不清楚。这项尸体研究旨在分析RSA植入和上肢位置对远端正中神经和radial神经张力的影响。假设是RSA增加了远端神经张力,这可能会进一步受到肘部和腕部位置的影响。
    解剖了9具新鲜冷冻尸体中的12个上肢。在近端手臂的正中神经中测量神经张力,弯头,和前臂远端,在肘部的radial神经中,使用定制的三点张力计。在RSA植入前后进行测量,使用半镶嵌植入物(Medacta,CastelSanPietro,瑞士)。测试了两种不同的配置,使用最小和最大的可用植入物尺寸。考虑了三个上肢关键位置(处于危险中的神经丛,神经丛缓解,和中性),进一步测试了肘部和腕部位置的影响。
    RSA植入显着增加了整个上肢的正中和radial神经张力。远端神经段特别依赖于肘部和腕部位置。处于危险位置的神经丛在所有神经段中引起最大的张力,特别是对于大的植入物配置。另一方面,神经丛缓解位置引起的张力最小。肘部弯曲是降低所有测试神经段和关键位置的神经张力的最有效方法。腕屈显著降低正中神经的神经张力,而腕部伸展减少了桡神经的张力。
    RSA显着增加了正中和radial神经的张力,并使它们更容易受到腕部和肘部定位的影响。因此,RSA后远端周围神经病变的机制可能是由于张紧神经对解剖支点的压缩增加而不是单独的神经伸长所致。肘部屈曲是降低神经张力的最有效方法,而在植入肱骨部件时应避免肘部伸展。需要进一步的研究来评估尺神经。
    UNASSIGNED: Peripheral nerve injury is a recognized complication after reverse shoulder arthroplasty (RSA) that has mainly been studied at the level of the brachial plexus and its proximal branches. However, the impact of RSA on distal peripheral nerves and the influence of elbow and wrist position is not known. This cadaveric study aimed to analyze the effect of RSA implantation and upper limb position on tension in the distal median and radial nerves. The hypothesis was that RSA increased distal nerve tension, which could be further affected by elbow and wrist position.
    UNASSIGNED: 12 upper limbs in 9 full fresh-frozen cadavers were dissected. Nerve tension was measured in the median nerve at the level of the proximal arm, elbow, and distal forearm, and in the radial nerve at the level of the elbow, using a customized three-point tensiometer. Measurements were carried out before and after RSA implantation, using a semi-inlay implant (Medacta, Castel San Pietro, Switzerland). Two different configurations were tested, using the smallest and largest available implant sizes. Three upper-limb key positions were considered (plexus at risk, plexus relief, and neutral), from which the effect of elbow and wrist position was further tested.
    UNASSIGNED: RSA implantation significantly increased median and radial nerve tension throughout the upper limb. The distal nerve segments were particularly dependent on elbow and wrist position. The plexus at risk position induced the most tension in all nerve segments, especially with the large implant configuration. On the other hand, the plexus relief position induced the least amount of tension. Flexing the elbow was the most efficient way to decrease nerve tension in all tested nerve segments and key positions. Wrist flexion significantly decreased nerve tension in the median nerve, whereas wrist extension decreased tension in the radial nerve.
    UNASSIGNED: RSA significantly increases tension in the median and radial nerves and makes them more susceptible to wrist and elbow positioning. The mechanism behind distal peripheral neuropathy after RSA may thus result from increased compression of tensioned nerves against anatomical fulcrums rather than nerve elongation alone. Elbow flexion was the most effective way to decrease nerve tension, while elbow extension should be avoided when implanting the humeral component. Further studies are needed to assess the ulnar nerve.
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  • 文章类型: Journal Article
    两亲性碳氟化合物物质由于其广泛的应用伴随着令人震惊的环境和健康影响而成为研究的热门话题。为了预测他们在环境中的命运,更经济地使用它们,开发新的水处理方法,等。,需要更好地了解它们的物理化学行为。它们在水/油系统中的疏水性对一个关键的热力学参数特别敏感:全氟亚甲基从油转移到水的自由能。然而,对于-CF2-部分,文献中报道的转移能量值变化超过±25%。由于该能量与吸附常数或分配系数之间的指数关系,这种不确定性会导致氟化物质预测分布的数量级误差。我们通过提供比目前可用的更大的确定性的-CF2-部分的疏水作用的实验测定来解决这个问题。通过测量短链氟调聚物醇水溶液的水|己烷的界面张力来确定传递能。在288.15K时,-CF2-部分从油转移到水的自由能的结果为1.68±0.02×RT0,1.75±0.02×RT0和1.88±0.02×RT0,293.15K,和303.15K,分别。
    Amphiphilic fluorocarbon substances are a trending topic of research due to their wide range of applications accompanied by an alarming environmental and health impact. In order to predict their fate in the environment, use them more economically, develop new water treatment methods, etc., a better understanding of their physicochemical behavior is required. Their hydrophobicity in water/oil systems is particularly sensitive to one key thermodynamic parameter: the free energy of transfer of a perfluoromethylene group from oil to water. However, for the -CF2- moiety, the transfer energy values reported in the literature vary by more than ±25%. Due to the exponential relationship between this energy and the adsorption constants or the partition coefficients, such an uncertainty can lead to orders of magnitude error in the predicted distribution of fluorinated species. We address this problem by presenting an experimental determination of the hydrophobic effect of a -CF2- moiety with a greater certainty than currently available. The transfer energy is determined by measuring the interfacial tension of water|hexane for aqueous solutions of short-chained fluorotelomer alcohols. The obtained results for the free energy of transfer of a -CF2- moiety from oil to water are 1.68±0.02×RT0, 1.75±0.02×RT0, and 1.88±0.02×RT0 at 288.15 K, 293.15 K, and 303.15 K, respectively.
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  • 文章类型: Journal Article
    几十年来,基于泥炭的肠衣已用于纽扣蘑菇(双孢蘑菇)种植,但存在寻找可持续替代品的环境压力。这项工作旨在表征泥炭和泥炭替代肠衣的理化特性,并确定它们对蘑菇种植的影响,以确定替代品。英国磨碎的泥炭和德国湿挖的泥炭肠衣比爱尔兰湿挖的泥炭肠衣产生的蘑菇要小,尽管产量不受影响。用25%v/v树皮替代碾磨或湿挖泥炭肠衣,绿色废物堆肥或废蘑菇肠衣,除了爱尔兰湿挖泥炭套管和废泥炭蘑菇套管,导致蘑菇产量和/或大小的减少。与爱尔兰湿挖泥炭套管相比,套管的这些较差结果对应于在基质电位(Wm)-15kPa下较低的保水量,但在饱和或-1kPa下排水后则没有。空气填充孔隙率(17-22%v/v),套管排水后压实的堆积密度(670-800gL-1)和电导率(0.30-0.54mScm-1)与其蘑菇种植性能无关。使用电子张力计进行的现场套管测量确认了实验室套管物理分析:在同一套管上,爱尔兰湿挖泥炭肠衣的含水量高于德国湿挖泥炭肠衣,并且以相同的产量生产了更大的蘑菇。基于固态泡沫的张力计比充满水的张力计更坚固,但在蘑菇冲洗过程中,它们没有检测到外壳kWm的完全减少。结果表明,如果可持续材料取代具有相同蘑菇产量和尺寸质量性能的湿挖泥炭肠衣,他们应该有相同的保水体积在Φm-15kPa。使用电子张力计测量肠衣Wm以控制蘑菇作物的灌溉应有助于这种过渡。
    Peat-based casings have been used for button mushroom (Agaricus bisporus) cultivation for decades but there is environmental pressure to find sustainable alternatives. This work aimed to characterise the physicochemical properties of peat and peat-substituted casings and to determine their influence on mushroom cropping to enable alternatives to be identified. British milled peat and German wet-dug peat casings produced smaller mushrooms than Irish wet-dug peat casing although yield was unaffected. Substitution of milled or wet-dug peat casings with 25% v/v bark, green waste compost or spent mushroom casing, except Irish wet-dug peat casing with spent peat mushroom casing, caused reductions in mushroom yield and/or size. These poorer results of casings compared with Irish wet-dug peat casing corresponded with lower water retention volumes at matric potential (Ψm) -15 kPa but not after drainage from saturation or at -1 kPa. Air-filled porosity (17-22% v/v), compacted bulk density after drainage (670-800 g L-1) and electrical conductivity (0.30-0.54 mS cm-1) of casings were unrelated to their mushroom cropping performance. In-situ casing measurements with electronic tensiometers confirmed laboratory casing physical analysis: at the same casing Ψm, Irish wet-dug peat casing had a higher water content than German wet-dug peat casing and produced larger mushrooms for the same yield. Solid-state foam-based tensiometers were more robust than water-filled tensiometers but they did not detect the full decrease in casing Ψm during a flush of mushrooms. The results indicate that if sustainable materials are to replace wet-dug peat casing with the same mushroom yield and size quality performance, they should have equivalent water retention volumes at Ψm -15 kPa. Measurement of casing Ψm with electronic tensiometers to control mushroom crop irrigation should assist in this transition.
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  • 文章类型: Journal Article
    目的:在髌股韧带重建过程中实现适当的移植物张力的最佳方法是一个争论的话题。在过去,使用数字张力计来模拟膝盖结构,大约2N的张力被确定为适用于恢复髌股轨道。然而,目前尚不清楚在实际手术过程中这种紧张程度是否足够。本研究的目的是使用数字张力计验证移植物张力在内侧髌股韧带(MPFL)重建中的功效,并进行中期随访。
    方法:该研究纳入了39例复发性髌骨脱位患者。术前计算机断层扫描和X射线证实髌骨不稳定,髌骨倾斜角髌骨全等角及脱位史和髌骨理解试验。使用术前和术后Lysholm和Kujala评分评估膝关节功能。
    结果:该研究包括39个膝盖,由22名女性和17名男性组成,平均年龄为21.10±7.26岁。通过电话或面对面问卷对患者进行至少24个月的随访。所有患者术前均有≥2次髌骨脱位,都没有手术治疗。手术期间,所有患者均接受了孤立的MPFL重建和外侧视网膜松解术.平均Kujala和Lysholm评分分别为91.28±4.90和90.67±5.15。平均PTA和PCA分别为11.5±2.63和2.38±3.58。研究发现,复发性髌骨脱位患者恢复髌股轨道需要约27.39±5.57N(14.3-33.5N)的张力。随访期间无患者需要再次手术。总的来说,39例患者中有36例(92.31%)在最后一次随访时完成日常活动时没有疼痛。
    结论:结论:在临床实践中,大约27.39±5.57N的张力水平是恢复正常的髌股关系所必需的,这表明使用2N的张力太低。在髌股韧带重建过程中使用张力计是治疗复发性髌骨脱位的更准确和可靠的手术方法。
    The optimal method for achieving proper graft tension during patellofemoral ligament reconstruction is a topic of debate. In the past, a digital tensiometer was used to simulate the knee structure, and a tension of approximately 2N was identified as suitable for restoring the patellofemoral track. However, it is unclear whether this tension level is sufficient during the actual surgery. The objective of this study was to verify the efficacy of graft tension using a digital tensiometer for medial patellofemoral ligament (MPFL) reconstruction and to conduct a mid-term follow-up.
    The study enrolled 39 patients who had experienced recurrent patellar dislocation. Preoperative computed tomography scans and X-rays confirmed patellar instability, patellar tilt angle patellar congruence angle and the history of dislocation and patellar apprehension test. Knee function was evaluated using preoperative and postoperative Lysholm and Kujala scores.
    The study included 39 knees, comprising 22 females and 17 males, with an average age of 21.10 ± 7.26. The patients were followed up for at least 24 months through telephone or face-to-face questionnaires. All patients had a preoperative history of ≥2 patellar dislocations, none of which were surgically treated. During surgery, all patients underwent isolated MPFL reconstruction and lateral retinacula release. The mean Kujala and Lysholm scores were 91.28 ± 4.90 and 90.67 ± 5.15, respectively. The mean PTA and PCA were 11.5 ± 2.63 and 2.38 ± 3.58, respectively. The study found that a tension of approximately 27.39 ± 5.57N (14.3-33.5N) was required to restore the patellofemoral track in patients with recurrent patellar dislocation. No patients required reoperation during the follow-up period. Overall, 36 out of 39 patients (92.31%) reported no pain when completing daily activities at the last follow-up.
    In conclusion, a tension level of approximately 27.39 ± 5.57N is necessary to restore normal patellofemoral relationships during clinical practice, which indicates that using a tension of 2N is too low. The use of a tensiometer during patellofemoral ligament reconstruction is a more accurate and reliable surgical procedure for treating recurrent patellar dislocation.
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  • 文章类型: Journal Article
    尽管许多非饱和土壤实验已经成功地取得了积极的成果,大多数研究只是简洁地说明了传感器技术,因为他们的主要目标集中在弥合研究差距上。没有经验的研究员可能很少跟进这些技术,所以他们可能会遇到非常琐碎和需要技能的困难,破坏实验结果的质量。为了避免这些,这项工作介绍了应用三种传感器技术的技术挑战:高精度张力计,空间时域反射计(空间TDR)和数字台秤,用于测量三个基本变量:土壤吸力,水分含量和累积流出。从功能机制、组装/制造方法,安装程序,同时数据记录配置和后期数据/信号处理。在这项工作中得出的结论提供了三个传感器在上述五个方面的足够的技术细节。这项工作旨在促进任何使用上述三个传感器进行实验室规模土壤柱测试的新研究人员。预计这项工作将挽救任何对这些传感器有故障排除问题的实验者,并帮助研究人员绕过这些问题,更多地关注他们的主要研究兴趣。
    Although many unsaturated soil experiments have successfully delivered positive outcomes, most studies just concisely illustrated sensor techniques, because their main objectives focused on bridging research gaps. Inexperienced research fellows might rarely follow up those techniques, so they could encounter very trivial and skill-demanding difficulties, undermining the quality of experimental outcomes. With a motivation to avoid those, this work introduces technical challenges in applying three sensor techniques: high precision tensiometer, spatial time-domain reflectometry (spatial TDR) and digital bench scales, which were utilized to measure three fundamental variables: soil suction, moisture content and accumulative outflow. The technical challenges are comprehensively elaborated from five aspects: the functional mechanism, assembling/manufacturing approaches, installation procedure, simultaneous data-logging configurations and post data/signal processing. The conclusions drawn in this work provide sufficient technical details of three sensors in terms of the aforementioned five aspects. This work aims to facilitate any new research fellows who carry out laboratory-scale soil column tests using the three sensors mentioned above. It is also expected that this work will salvage any experimenters having troubleshooting issues with those sensors and help researchers bypass those issues to focus more on their primary research interests.
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  • 文章类型: Journal Article
    尾矿坝很大,通常是自给自足的,矿渣储存设施。在独立的尾矿坝上,尾矿材料本身用于升高容纳新沉积残留物的围护堤。为了发展必要的力量,重要的是材料必须充分干燥。尽管在仪器仪表领域取得了长足的进步,这些参数很少在尾矿坝上测量,并且对它们随时间的演变知之甚少。了解孔隙水吸力和水含量随时间演变的作用可以受益于能够连续监测这些参数的传感器和数据采集系统(DAQ)的安装。由于测量负水压的挑战以及通常偏远的位置和采矿作业典型的恶劣操作环境,这种监测仍然困难且昂贵。本文描述了发展,测试和验证低成本DAQ,用于测量位于南非林波波省的铂尾矿坝的非饱和孔压状态。尾矿坝DAQ(简称TD-DAQ)用于测量负孔隙压力,长时间内细粒材料中的水分含量和温度。这些测量值存储在DAQ上,并使用新的无线网络通信技术(Sigfox)并行传输,电池供电的应用。TD-DAQ的成功部署提供了一种实时、低成本的仪表解决方案,以提高尾矿储存设施的状态监测效率,有助于降低故障事件的概率。
    Tailings dams are large, often self-contained, storage facilities of mine residue. On self-contained tailings dams the tailings material itself is used to raise the containment embankments holding newly deposited residue. To develop the necessary strength, it is essential that material must dry out sufficiently. Despite substantial advancements in the field of instrumentation, these parameters are rarely measured on tailings dams and their evolution over time is poorly understood. Understanding the role of pore water suction and water content evolution over time can benefit from the installation of sensors and data acquisition systems (DAQ) capable of continuously monitoring these parameters. Such monitoring remains difficult and expensive owing to the challenges of measuring negative water pressures and the often-remote locations and harsh operating environments typical of mining operations. This paper describes the development, testing and validation of a low-cost DAQ for the measurement of the unsaturated pore pressure regime in a platinum tailings dam located in the Limpopo province of South Africa. The Tailings Dam DAQ (referred to as TD-DAQ) is designed to measure the negative pore pressure, moisture content and temperature in fine-grained material over extended periods of time. These measurements are stored on the DAQ and transmitted in parallel using new wireless network communications technologies (Sigfox) suited to remote, battery powered applications. The successful deployment of the TD-DAQ presents a real-time, low-cost instrumentation solution to improve the efficiency of condition monitoring of tailings storage facilities, contributing to a reduction in the probability of failure events.
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  • 文章类型: Journal Article
    After surgery, around 35% of patients experience problems of excessive scarring, causing disfiguring and impaired function. An incision placed in the wrong direction causes unnecessary skin tension on the wound, resulting in increased collagen disposition and potentially hypertrophic scars. Currently, skin tension lines are used for incision planning. However, these lines are not universal and are a static representation of the skin tension that is in fact under influence of muscle action. By designing a new skin force measurement device the authors intend to make research on dynamic skin characteristics possible and to objectify incision planning and excision closure planning. The device applies a known compressive force to the skin in standardized directions and measures the displacement of the skin. This allows users to measure the skin reaction force in response to compression and to determine the optimal incision line or best wound closure direction. The device has an accuracy of 96% and a sensitivity of < 0.01 mm. It is compact, works non-invasively and standardizes measurement directions and is therefore an improvement over previously designed skin tensiometers.
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  • 文章类型: Journal Article
    改进各种工艺的愿望,如提高采油率(EOR),水处理技术,生物质提取,有机合成,碳捕获等。传统上使用常规表面活性剂;促使各种研究人员探索不同种类的表面活性分子的自组装和聚集行为。具有长烷基链的离子液体(IL)的结构构成了表面活性剂和IL的有利性质,因此被称为表面活性离子液体(SAIL)。IL和SAIL的添加显着影响工业上有用的常规表面活性剂的表面活性和聚集行为。在简要回顾了IL之后,SAIL和表面活性剂,重点是分析SAIL的自组装和不同IL的常规表面活性剂的混合胶束行为。
    The desire of improving various processes like enhanced oil recovery (EOR), water treatment technologies, biomass extraction, organic synthesis, carbon capture etc. in which conventional surfactants have been traditionally utilized; prompted various researchers to explore the self-assembly and aggregation behavior of different kinds of surface-active molecules. Ionic liquids (ILs) with long alkyl chain present in their structure constitute the advantageous properties of surfactant and ILs, hence termed as surface-active ionic liquids (SAILs). The addition of ILs and SAILs significantly influence the surface-activity and aggregation behavior of industrially useful conventional surfactants. After a brief review of ILs, SAILs and surfactants, the prime focus is made on analyzing the self-assembly of SAILs and the mixed micellization behavior of conventional surfactants with different ILs.
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  • 文章类型: Letter
    暂无摘要。
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  • 文章类型: Journal Article
    OBJECTIVE: To evaluate intercompartmental load intraoperatively with a sensor after conventional gap balancing with a tensiometer during total knee arthroplasty (TKA).
    METHODS: Fifty sensor-assisted TKA procedures were performed prospectively between August and September 2018 with a cruciate-retaining prosthesis. After applying a modified measured resection technique, conventional balancing between resected surfaces was achieved. The equal and rectangular flexion-extension gaps were confirmed using a tensiometer at 90° and 5°-7° (due to posterior tibial slope) of knee flexion. Then, the load distribution was evaluated intraoperatively with a sensor placed on trial implants in the positions of knee flexion (90° flexion) and extension (10° flexion).
    RESULTS: The proportion of coronal load imbalance (medial load - lateral load ≥  ± 15 lb) was 56% in extension and 32% in flexion (p = 0.023). The proportion of sagittal load imbalance (extension load - flexion load ≥  ± 15 lb) was 36% in the medial compartment and 4% in the lateral compartment (p < 0.001). An additional procedure for load balancing was performed in 74% of knees.
    CONCLUSIONS: Coronal and sagittal load imbalances existed as determined by the sensor even after the achievement of appropriate conventional gap balance. The additional rebalancing procedure was performed for balanced loads in 74% of the knees after conventional balancing. The use of an intraoperative load sensor offers the advantage of direct evaluation of the load on TKA implants.
    METHODS: IV.
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