Sound transmission testing of polymer compounds

This is the post-print version of the final paper published in Polymer Testing. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2012 Elsevier Ltd.Acoustic properties of polymer compounds are an important consideration for many applications. Currently, there are standard test methods for the determination of these properties. There is, however, no standard for the equipment used in these tests, only a specification for the test conditions. The objective of this work was to evaluate the operation and performance of a bench top laboratory sound testing system for its potential as a simple cost effective method for the initial evaluation of materials that require specific acoustic properties. The work was limited to an investigation of the property of sound transmission loss (STL). A study of the effect of the mounting conditions for the samples on the STL was carried out. Following this, a series of polymer and polymer composite samples was tested. The results presented demonstrate the potential for the testing system as an effective standard test method for the acoustic properties of polymer composites and other materials.Technology Strategy Board, U

Energy Absorption of Macrocomposite Laminates

PhDThe aim of this project was two-fold. Firstly to provide an understanding of the behaviour of SMC when subjected to drop weight impact and secondly to investigate the effect of a surface layer of a metallic material (stainless steel, aluminium, brass and copper) and a layer of Ionomer on the impact behaviour of SMC. Tensile, flexural, compression, shear, charpy and drop weight impact tests were carried out on SMC (Sheet Moulding Compound). The response of SMC and various combinations of SMC and metal sheet (stainless steel, aluminium, brass and copper) and SMC with a layer of Ionomer to impact load have been assessed using an Instrumented Falling Weight Impact test machine. Slow indentation tests and a variety of destructive and non-destructive test techniques were used to monitor the initiation and propagation of damage and relate them to the major features of typical force-time curves obtained during impact. The deformation of the metallic layer was compared under impact and slow test and a calibration curve was produced. By using the calibration curve the energy absorbed by SMC and SMC as a layer in SMC+metal laminate was compared and results were related to stiffness and ductility of the metallic layer. The energy absorbed by the SMC-metal laminates were analysed and the energy absorbed by each constituents was determined. The effect of impact damage on tensile and compressive residual strength was assessed by conducting tension and compression test on the damaged specimens. Finally, a number of simple models and fInite element technique were used to predict the impact response of SMC and SMCmetal laminates to impact. The results of the research programme indicated a strong macrocomposite effect resulting in greatly improved energy absorbing capabilities for SMC. The indications were that a metal layer was required that would be stiff, thereby putting the SMC into compression and also ductile in order to support extensive deformation in the SMC whereby microcracking could accumulate

Investigating Performance of Windscop Installed on Towers in Arid Regions with Using Computational Fluid Dynamics (Case Study: I&M Bank in Nairobi)

ABSTRACT: The windscops are designed mainly to direct the wind and fresh air in the buildings. The windscops are able to gather the outside air and direct it into the building. If we want to make a windscops very effective, it shall be able to rotate on all directions. The windscops performance reaches to its top point when they are designed to direct the air for a big hall like an amusement park, etc. In this paper we paid more of our focus on performance analysis for a type of windscops which are installed on tower peaks. At first, we conducted analysis by means of GAMBIT software regarding the geometric model of windscops and the structure analysis, and then we continued to analyze them by means of FLUENT software regarding their pattern of flow. The results of such analyses were demonstrated as velocity on X&Y directions, and flow pattern

Knowledge Graphs Effectiveness in Neural Machine Translation Improvement

Neural Machine Translation (NMT) systems require a massive amount of Maintaining semantic relations between words during the translation process yields more accurate target-language output from Neural Machine Translation (NMT). Although difficult to achieve from training data alone, it is possible to leverage Knowledge Graphs (KGs) to retain source-language semantic relations in the corresponding target-language translation. The core idea is to use KG entity relations as embedding constraints to improve the mapping from source to target. This paper describes two embedding constraints, both of which employ Entity Linking (EL)---assigning a unique identity to entities---to associate words in training sentences with those in the KG: (1) a monolingual embedding constraint that supports an enhanced semantic representation of the source words through access to relations between entities in a KG; and (2) a bilingual embedding constraint that forces entity relations in the source-language to be carried over to the corresponding entities in the target-language translation. The method is evaluated for English-Spanish translation exploiting Freebase as a source of knowledge. Our experimental results show that exploiting KG information not only decreases the number of unknown words in the translation but also improves translation quality

An uncommon manifestation of renal cell carcinoma: contralateral spermatic cord metastasis

چکیده: زمینه و هدف: کارسینوم سلول کلیوی (RCC) با تظاهرات متفاوتی مشخص می شود که شامل متاستازهای غیر معمول و سندرم های پارانئوپلاستیک است. معرفی بیمار: بیمار آقای 60 ساله ای است که 7 سال پیش به دلیل تشخیص کارسینوم سلول کلیوی چپ تحت عمل جراحی نفروکتومی قرار گرفته بود. پس از 7 سال به دلیل لمس توده ای در همی اسکروتوم راست خود مراجعه نمود. در پاتولوژی بیمار متاستاز کارسینوم سلول کلیوی چپ به اسپرماتیک کورد سمت مقابل گزارش گردید و برای بیمار تصمیم به ارکیکتومی گرفته شد. نتیجه گیری: متاستاز RCC به وریدهای اسپرماتیک می تواند از طریق جریان رتروگراد از ورید کلیه انجام گیرد، لذا در بیماران باRCC در طی فالواپ ،معاینه دقیق ژنیتال خارجی برای رد متاستازهای مخفی باید انجام شود

Adaptive Projective Lag Synchronization of T and Lu Chaotic Systems

In this paper, the synchronization problem of T chaotic system and Lu chaotic system is studied. The parameter of the drive T chaotic system is considered unknown. An adaptive projective lag control method and also parameter estimation law are designed to achieve chaos synchronization problem between two chaotic systems. Then Lyapunov stability theorem is utilized to prove the validity of the proposed control method. After that, some numerical simulations are performed to assess the performance of the proposed method. The results show high accuracy of the proposed method in control and synchronization of chaotic systems

Modified Projective Synchronization of Chaotic Systems with Noise Disturbance, an Active Nonlinear Control Method

The synchronization problem of chaotic systems using active modified projective nonlinear control method is rarely addressed. Thus the concentration of this study is to derive a modified projective controller to synchronize the two chaotic systems. Since, the parameter of the master and follower systems are considered known, so active methods are employed instead of adaptive methods. The validity of the proposed controller is studied by means of the Lyapunov stability theorem. Furthermore, some numerical simulations are shown to verify the validity of the theoretical discussions. The results demonstrate the effectiveness of the proposed method in both speed and accuracy points of views

Eremostachys laevigata Bunge responses to different extraction solvents and methods: physiological, biochemical, and antibacterial attributes

This study examined the biochemical composition of Eremostachys laevigata Bunge's aerial and underground organs using various solvents (methanol, water, N-hexane, chloroform, and acetone) and their impact on antibacterial activity against eight bacterial strains (Escherichia coli, Staphylococcus aureus, Salmonella enterica, Pseudomonas aeruginosa, Klebsiella pneumoniae, Shigella dysenteriae, Proteus mirabilis, and Bacillus cereus). Soxhlet and maceration extraction methods were used, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using the tube dilution method. The study found that N-Hexane and water solvents had the highest total phenol content, while methanol, acetone, and chloroform had the lowest. Additionally, N-Hexane and methanol solvents showed the highest and lowest flavonoid content, respectively. The methanol extract from underground organs using the Soxhlet method exhibited the strongest antibacterial activity, whereas the acetone extract showed the weakest antimicrobial effect. Staphylococcus aureus displayed both the MIC and MBC, and Salmonella enterica showed the highest susceptibility to the well diffusion method, while both Escherichia coli and Staphylococcus aureus were highly susceptible to the disk diffusion method. The underground organs contained 6.87 mg.g-1 of phenolic compounds and 0.19 mg.g-1 of flavonoids. Two iridoid glycosides, pholoyoside and sesamoside, were separated from the methanol extract of the underground organs using reversed-phase HPLC. The research highlights E. laevigata Bunge's potential as a natural reservoir of antimicrobial compounds, with phenolic and flavonoid compounds, along with iridoid glycosides, presumed to contribute to its antibacterial properties

Evaluation of techniques to break seed dormancy in Redroot pigweed (Amaranthus retroflexus)

If we understand factors that trigger seed dormancy release, then we can accurately predict whether the seed will remain dormant or germinate out of the seed bank. With regards to annual weed species, detailed understanding of what breaks seed dormancy is therefore critical for determining how many weed seeds will germinate into problematic weeds. To investigate the breaking of dormancy in weed seeds, we conducted an experiment with Redroot pigweed (Amaranthus retroflexus). Dormant seeds were treated with cold stratification (4 °C for 30 days), application of gibberellic acid (at 500, 1000, 1500, and 2000 parts per million) or ultrasound (for 10, 20, 30, and 40 minutes), soaking in hot water (90 °C for 3, 5, 7 and 10 minutes) or 98% sulfuric acid (for 1, 2 and 3 minutes) to determine which treatment most effectively broke dormancy. The results showed that Redroot pigweed seed dormancy was effectively broken by cold stratification, gibberellic acid, or ultrasound. Short treatments with hot water had minimal effect while longer times or treatment with sulfuric acid eliminated seed germination. In addition to germination percentage, germination rate, plumule length, radicle length, seedling length, seedling dry weight, and seed vigor index were also measured; similarly application of gibberellic acid had the most significant effect on these parameters. The results of this study add to our understanding of what processes effectively or ineffectively break Redroot pigweed seed dormancy and promote growth

The Results of Whole Exome Sequencing Performed On Previously Undiagnosed Pediatric Neurology Patients

  Objective Whole exome sequencing (WES) is a new molecular diagnostic test, used in pediatric medicine, especially pediatric neurology. The diagnostic yield of WES is higher than conventional methods. Therefore, this study aimed to assess the diagnostic yield of WES in a pediatric neurology clinic and to report positive results. Materials & Methods This retrospective study was performed on patients, presenting to the pediatric neurology clinic of Ghaem Hospital in Mashhad, Iran, between March 2015 and March 2017, with various neurological disabilities and unrevealing workup before WES. The patients’ clinical features and molecular diagnoses based on the WES Results were reported in this study. The overall diagnostic yield of WES was 82.71% (67/81 patients). Two patients were excluded for the lack of data. Sixty-five patients with pathogenic or possibly pathogenic variants exhibited various abnormalities, including intellectual disability/developmental delay (n=44), seizure (n=27), developmental regression (n=11), myopathy (n=9), microcephaly (n=8), neuropathy (n=2), autism spectrumdisorder (n=2), and neuromuscular disease (n=2). Overall, 93.84% of the patients were born to consanguineous parents. Also, 62 patients had an autosomal recessive disorder, and three patients had an autosomaldominant disorder. Conclusion The present findings indicating the high diagnostic yield of WES, besides the important role of this test in determining the etiology of non-specific and atypical presentations of genetic disorders, support the use of WES in pediatric neurology practice