Lubrication

润滑
  • 文章类型: Journal Article
    目标:粘贴是片剂制造过程中最常见和最具破坏性的问题之一。粘附是在压缩期间粉末粘附到工具表面上。由于它的发生涉及众多因素,了解片剂粘附需要同时研究这些因素,以阐明它们可能的相互作用。然而,通过实验进行这样的研究可能会带来巨大的财务和技术负担。在这项研究中,我们的目标是利用工业制造过程中通常产生的大量数据来获得对粘附的见解。方法:这是通过收集和分析总共71个使用基于布洛芬的制剂的历史批次来实现的。我们将每个批次与一百个参数相关联,包括一个定性的粘滞描述符,并采用主要基于多变量数据分析的预定义方法。结果和结论:我们的结果强调了润滑的作用,含水量,低熔点布洛芬的粘附倾向。基于这些发现,我们提出并讨论了一种工业制造数据分析方法及其相关的系统方法论,由收集组成,探索,和数据建模。
    UNASSIGNED: Sticking is one of the most common and damaging issues that occur during tablet manufacturing. Sticking is the adhesion of powder onto tooling surfaces during compression. Because of the numerous factors involved in its occurrence, understanding tablet sticking requires the simultaneous investigation of these factors to clarify their possible interactions. However, conducting such a study experimentally can present a significant financial and technical burden. In this study, we aimed to leverage the large amount of data that is usually generated during industrial manufacturing to gain insights into sticking.
    UNASSIGNED: This was achieved by collecting and analyzing a total of 71 historical batches that used an ibuprofen-based formulation. We associate each batch with a hundred parameters, including a qualitative descriptor of sticking, and employ a predefined methodology based primarily on multivariate data analysis.
    UNASSIGNED: Our results highlight the role of lubrication, water content, and the low melting point of ibuprofen in its sticking tendency. Based on these findings, we propose and discuss an industrial manufacturing data analysis approach to sticking and its associated systematic methodology, consisting of collection, exploration, and data modeling.
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  • 文章类型: Case Reports
    BACKGROUND: This study describes the use of a moisture chamber to treat corneal ulceration due to temporary lagophthalmos in a critically ill patient.
    METHODS: A 46-year-old woman was admitted to the intensive care unit after a car accident. She suffered multiple injuries that included brain injury and presented with moderately decreased consciousness and lagophthalmos in her right eye. Within 6 d, her consciousness improved considerably; at which time, exposure keratopathy occurred and worsened to corneal ulceration. Lubricating gel, antibiotic ointment, and bandage contact lens were all ineffective in preventing or treating the exposure keratopathy. Instead of tarsorrhaphy, a moisture chamber was applied which successfully controlled the corneal ulceration. The moisture chamber was discontinued when complete eyelid closure recovered a week later.
    CONCLUSIONS: A moisture chamber may be an effective, noninvasive alternative to tarsorrhaphy for treating severe exposure keratopathy due to temporary lagophthalmos.
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  • 文章类型: Case Reports
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  • 文章类型: Journal Article
    The structural and frictional properties of 10 wt % solutions of the amphiphilic molecules glycerol monooleate (GMO) and polyisobutylsuccinimide-polyamine (PIBSA-PAM) in squalane are studied using molecular dynamics simulations in bulk and under confinement between iron oxide surfaces. GMO is a friction modifier, PIBSA-PAM is a dispersant, and squalane is a good model for typical base oils. A range of liquid compositions and applied pressures is explored, and the formation and stability of reverse micelles are determined under quiescent and shear conditions. Micellization is observed mainly in systems with a high GMO content, but PIBSA-PAM may also form small aggregates on its own. In the confined systems under both static and shear conditions, some surfactant molecules adsorb onto the surfaces, with the rest of the molecules forming micelles or aggregates. Shearing the liquid layer under high pressure causes almost all of the micelles and aggregates to break, except in systems with around 7.5 wt % GMO and 2.5 wt % PIBSA-PAM. The presence of micelles and adsorbed surfactants is found to be correlated with a low kinetic friction coefficient, and hence, there is an optimum composition range for friction reduction. This work highlights the importance of cooperative interactions between lubricant additives.
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  • 文章类型: Journal Article
    我们描述了一种在基于人群的膀胱癌病例对照研究中估计研究对象暴露于金属加工液(MWF)的概率的方法。关于特定MWF的加工频率和使用的研究主题报告(直,可溶性,和合成/半合成)用于估计暴露概率。这些报告还被用来为工作群体制定估计,然后应用于没有MWF报告的工作。仅使用病例和对照和对照进行了估计。加工的患病率在不同的工作群体中差异很大(0.1->0.9%),机械师、工具和模具工人报告的加工工作比例最高。有关直接和可溶MWF使用的报告在各个工作组之间相当一致(通常为50-70%)。合成MWF使用率较低(13-45%)。病例和对照报告与对照报告差异不大仅控制。大约,整个研究人群的1%被评估为明确暴露于直接或可溶性流体,而0.2%则明确暴露于合成/半合成材料。报告的MWF使用与美国生产水平之间的比较发现高度相关(r通常>0.7)。总的来说,本文描述的方法可能提供了系统和可靠的排名,与过去使用的方法相比,该排名更好地反映了暴露于三种类型MWF的变异性。【本文有补充材料。请访问出版商的在线版《职业与环境卫生杂志》,获取以下免费补充资源:职业历史中用于将研究主题与金属加工液(MWFs)模块链接的关键字列表;有关基于加工操作类型选择MWFs的文献建议,正在加工的金属和十年;MWF的流行添加剂;按工作组报告各种MWF响应的控件的数量和比例;按工作组和暴露类别分配给MWF类型的控件的数量和比例;以及按MWF类型分配不同概率级别的案例和控件的分布。].
    We describe an approach for estimating the probability that study subjects were exposed to metalworking fluids (MWFs) in a population-based case-control study of bladder cancer. Study subject reports on the frequency of machining and use of specific MWFs (straight, soluble, and synthetic/semi-synthetic) were used to estimate exposure probability when available. Those reports also were used to develop estimates for job groups, which were then applied to jobs without MWF reports. Estimates using both cases and controls and controls only were developed. The prevalence of machining varied substantially across job groups (0.1->0.9%), with the greatest percentage of jobs that machined being reported by machinists and tool and die workers. Reports of straight and soluble MWF use were fairly consistent across job groups (generally 50-70%). Synthetic MWF use was lower (13-45%). There was little difference in reports by cases and controls vs. controls only. Approximately, 1% of the entire study population was assessed as definitely exposed to straight or soluble fluids in contrast to 0.2% definitely exposed to synthetic/semi-synthetics. A comparison between the reported use of the MWFs and U.S. production levels found high correlations (r generally >0.7). Overall, the method described here is likely to have provided a systematic and reliable ranking that better reflects the variability of exposure to three types of MWFs than approaches applied in the past. [Supplementary materials are available for this article. Go to the publisher\'s online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resources: a list of keywords in the occupational histories that were used to link study subjects to the metalworking fluids (MWFs) modules; recommendations from the literature on selection of MWFs based on type of machining operation, the metal being machined and decade; popular additives to MWFs; the number and proportion of controls who reported various MWF responses by job group; the number and proportion of controls assigned to the MWF types by job group and exposure category; and the distribution of cases and controls assigned various levels of probability by MWF type.].
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  • 文章类型: Journal Article
    背景:系统,透明,并开发了数据驱动的方法来估计暴露于直线的频率和强度,可溶性,和合成/半合成金属加工液(MWFs)在新英格兰膀胱癌的病例对照研究中。
    方法:我们尽可能使用来自特定工作问卷的个人水平信息评估频率,然后导出作业组级别的模式,并将其应用于具有较少信息的可能暴露的作业。使用从已发表文献中提取的测量和决定因素开发的统计模型来计算强度估计值。
    结果:对于暴露概率≥0.5的工作,中位频率为8-10小时/周,根据MWF类型。这些工作的平均强度分别为2.5、2.1和1.0mg/m3的可溶物,直,和合成/半合成MWF,分别。
    结论:与个案评估相比,这些数据驱动的决策规则是透明和可重复的,并且可能导致较少偏差的估计.这些规则还可以帮助未来在基于人群的研究中对MWF的暴露评估。
    BACKGROUND: A systematic, transparent, and data-driven approach was developed to estimate frequency and intensity of exposure to straight, soluble, and synthetic/semi-synthetic metalworking fluids (MWFs) within a case-control study of bladder cancer in New England.
    METHODS: We assessed frequency using individual-level information from job-specific questionnaires wherever possible, then derived and applied job group-level patterns to likely exposed jobs with less information. Intensity estimates were calculated using a statistical model developed from measurements and determinants extracted from the published literature.
    RESULTS: For jobs with probabilities of exposure≥0.5, median frequencies were 8-10 hr/week, depending on MWF type. Median intensities for these jobs were 2.5, 2.1, and 1.0 mg/m3 for soluble, straight, and synthetic/semi-synthetic MWFs, respectively.
    CONCLUSIONS: Compared to case-by-case assessment, these data-driven decision rules are transparent and reproducible and may result in less biased estimates. These rules can also aid future exposure assessments of MWFs in population-based studies.
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  • 文章类型: Journal Article
    Major benefit uncertainties prevent monetary quantification of some environmental amenities. Replacing mineral lubricants with biodegradable substitutes is shown to be a case in point. However, it is possible to rank the social benefits of substituting mineral lubricants with regard to different applications and environments. As the private costs and benefits of substitution are mainly constant, only a policy that prioritizes full substitution in the applications with the greatest benefits can be efficient. It is shown that regulations requiring substitution in certain fields are likely to fulfil this criterion, while subsidies for production, processing, market introduction and research usually fail to meet the efficiency criterion.
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  • 文章类型: Case Reports
    Congenital eversion of the upper eyelids is a rare condition, the exact cause of which remains unknown. It is more frequently associated with Down\'s syndrome and black babies. If diagnosed early and treated properly, the condition can be managed without surgery. We report a case of congenital bilateral severe upper eyelid eversion in a normal infant, born by vaginal delivery. The case was conservatively managed by lubricants, antibiotics and eyelid patching.
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  • DOI:
    文章类型: Case Reports
    New technology was used to identify traces of a commercial barrier/spermicide in evidence from a case of a man accused of rape of a minor. Examination of vaginal swabs performed by another laboratory had been negative for seminal fluid or other sources of DNA from the suspect and we were asked to examine the remaining swabs for any traces that might have originated from the commercial product. Encare consists of vaginal inserts having a suppository-like shape. They contain the spermicide, nonoxynol-9, in a matrix consisting of approximately two parts polyethylene glycol (PEG) 1000 to one part PEG 1450, plus minor inorganic components added to produce foaming. Portions of the cotton from vaginal swabs from the victim and penile swabs from the suspect were extracted with methanol and subsequently examined by desorption ionization on silicon time-of-flight mass spectrometry (DIOS TOF MS). Low levels of PEG in the same mass range as Encare were found on two separate vaginal swabs from the victim and one penile swab from the suspect. Subsequent to these findings, the suspect (through his attorneys) provided us with a sample of SLIP Plus, a commercial sexual lubricant that also contains nonoxynol-9. Traces of PEG in the same mass range as Encare were found in this sample, while no PEG was found in a sealed sample of SLIP Plus provided by the manufacturer. At trial the suspect\'s attorneys stipulated that their client had added some Encare to the SLIP Plus sample he had provided.
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  • 文章类型: Case Reports
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