A novel simultaneous photoelastic and two‐beam interferometric system: I. Dynamic full‐field evaluation of the elasticity modulus profile of polymeric fibres

A novel optical setup for simultaneous capturing of photoelastic and two‐beam interference patterns was designed. The designed optical setup was used to simultaneously record two types of patterns. The first pattern is two‐beam interference pattern, and the second one is photoelastic interference pattern produced by objects under stress. This simultaneous capturing of the two patterns allowed us to calculate the full‐field distribution of the elasticity modulus profile of fibres. A mathematical expression of the profile of the elasticity modulus was derived. This was applied to evaluate the elasticity modulus of anisotropic isotactic polypropylene fibres during stretching processes. The profile of the elasticity modulus was determined for both static and dynamic in situ cases where the propagation of different structural deformations was observed and studied using the designed optical setup. Patterns were given for illustration.     

The impact of processing conditions on the structural and optical properties of the as‐spun polyamides fibers

The development of crystallinity and orientation during the melt spinning of polyamides (nylon 66) was investigated. This study reports the question of the orientation and crystallinity determination of nylon 66 by means of differential scanning calorimetry, optical polarized microscope, and X‐ray diffraction techniques during the cold drawing process. The different structural properties such as crystallinity, crystal size, birefringence, and different orientation functions were measured as a function of the draw ratio. From the obtained thermogram, it is clear that the melting temperature of the drawn nylon 66 fibers did not show a significant change due to the cold drawing process. As the draw ratio increase, the crystallinity and crystal size increase. The drawing process improves the chain orientations along the fiber axis of nylon 66 fibers. The orientations of the chain segments enhanced due to the cold drawing process of nylon 66 fibers.     

Microstructure and creep characteristics of experimental SiCf–YMAS composites

A unidirectional SiC_f –YMAS glass–ceramic composite has been developed by Céramiques-Composites (Bazet) and ONERA (Establishment of Palaiseau) in France. The matrix is totally crystalline and consists essentially of two main phases, cordierite and yttrium disilicate, with some minor phases, mullite, spinel, zirconium and titanium oxides. Image analysis methods have been used to characterize the homogeneity of the composite plates and to obtain granulometric information on the different matrix phases. Different interphase layers formed during the process by reaction between the matrix and the Nicalon NLM 202 fibres have been studied by using HREM and EDX. Their chemical composition has been determined by stepping the probe (8 nm) across the fibre–matrix interface. Two distinct nanoscale sublayers have been imaged. The sublayer on the matrix side has a light contrast in the TEM. The microstructure of this layer (≈ 80 nm) is typical of a turbostratic carbon. The carbon layer also contains Al, O, Mg and Si. The silicon content is low in the carbon layer. The sublayer on the fibre side (≈ 100 nm thick) has a dark contrast in the TEM. Profiles have been taken across this sublayer also. Tensile creep tests in air have been performed to investigate the tensile creep behaviour at 1223 K. They have been conducted in the 50–200 MPa stress range. Tensile creep results indicate that creep rates are of the same order of magnitude as for other glass–ceramic composites. Optical micrographs and SEM observations have revealed the damage in the composite. Changes occurring in the interface region have been studied at a finer scale by TEM and HREM at the surface of the sample and in the core. These observations enable us to explain the mechanical behaviour of the composite observed on a macroscopic scale.     

Nonray‐tracing determination of the 3D refractive index profile of polymeric fibres using single‐frame computed tomography and digital holographic interferometric technique

In this paper, we present a nonray‐tracing technique for evaluating the three dimensional distribution of the refractive index values inside polymeric fibres. This technique, named ‘single‐frame computed‐tomography (SFCT)’, is applied to digital holography. A comparative study between the calculated optical phase values using ordinary tomography and SFCT is carried out, and a negligible deviation is detected. The proposed technique is used to determine the three‐dimensional refractive index profile of isotactic Polypropylene fibres, IPP. The variation of the optical properties is measured before, during and after the formation of the necking phenomenon. In addition, SFCT technique is applied to the online determination of the change of the optical properties of IPP fibres. Holograms are given for illustration.     

A tribological study of (2‐sulphurone‐benzothiazole)‐3‐methyl‐dibutyl borate

An organic compound containing S, N, B, and O was synthesised by reacting 2‐mercaptobenzothiazole and formalin in ethanol solution, the resulting product then being reacted with butanol and boric acid in toluene solution. The tribological performance of the novel compound when added to liquid paraffin was evaluated using a four‐ball tester and a ring‐on‐block machine. The relationship between performance and concentration was analysed, and the results show that the compound possesses good antiwear and load‐carrying abilities. The mechanism of action of the additive was investigated using X‐ray photo‐electron spectroscopy (XPS). Surface analysis indicated the formation of a protective film containing FeSO₄, an organo‐sulphur compound, FeS₂, borate, and an organonitrogen compound. This protective film formed during sliding processes contributes to the increase in wear resistance.     

Morphological changes of poly(DI‐lactide‐co‐glycolide) nano‐particles containing ascorbic acid during in vitro degradation process

Poly(dl ‐lactide‐co‐glycolide) powder composed of uniform particles with the mean particle size in the range of 110–170 nm was obtained from commercial granules. Ascorbic acid in different concentrations was encapsulated into the poly(dl ‐lactide‐co‐glycolide) particles. Degradation of the latter in terms of morphological changes in the physiological solution was followed. Within a period of 2 months, the particles completely degrade and all the ascorbic acid is released. The samples were characterized by ultraviolet spectroscopy and scanning electron microscopy.     

冷辗扩工艺中环件锻透变形的数值分析与试验

冷辗扩机床是目前世界上生产轴承套圈的先进设备.在辗压环件过程中存在着接触非线性和材料非线性双重复杂的变化过程.采用ANSYS有限元分析软件对复杂的辗扩过程进行数值仿真.根据锻透条件,计算出不同工况条件下的最小辗压力,为模具的设计及进给机构参数设计提供了依据.同时进行试验验证分析.     

A test method to study the change in surface topography due to running‐in of a rolling contact

A method is proposed to determine the change in surface topography during running‐in of rolling contacts. Two types of experiments have been conducted in the present work to study the running‐in of the pure rolling contact situation: repeated moving and general free rolling using a high accuracy measurement setup. The results show that the surfaces run‐in with the proposed repeated moving contact method gives a fast running‐in when compared with the general free rolling contact method. The proposed repeated moving contact method appears to be a good method to study the ideal or pure rolling contact situation because wear, as present in the general free rolling contact method, is avoided. Copyright © 2013 John Wiley & Sons, Ltd.     

Morphology study of progesterone polymorphs prepared by polymer‐induced heteronucleation (PIHn)

In this article, morphology of progesterone polymorphs prepared by polymer‐induced heteronucleation (PIHn) technique was studied. Hydroxypropyl methylcellulose(HPMC), such as dextran T‐500 and gelatin G‐9382, polyisoprene (PI), and acrylonitrile/butadiene copolymer (NBR) were used as substrates. The crystallizations were performed by solvent evaporation at room temperature from 0.5, 10, and 40 mg/ml solutions in chloroform and acetone. Progesterone polymorphs were identified by X‐ray diffraction. Differential scanning calorimetry and total attenuated reflectance infrared spectroscopy were used as complementary techniques in the identification. Depending on the polymeric matrix and the concentration used, form 1, form 2, or mixture of both polymorphs were obtained. Scanning electron microscopy pictures evidenced difference in morphology and in homogeneity of the two progesterone polymorphs. These polymorphs prepared by PIHn, did not present a distinctive morphology that allows identifying polymorph by its crystal habit. Hence, polymeric matrix induced the crystallization, affecting polymorphism and morphology. SCANNING 35:213‐221, 2013. © 2012 Wiley Periodicals, Inc.     

Ion mobility spectrometry‐mass spectrometry (IMS‐MS) of small molecules: Separating and assigning structures to ions

The phenomenon of ion mobility (IM), the movement/transport of charged particles under the influence of an electric field, was first observed in the early 20th Century and harnessed later in ion mobility spectrometry (IMS). There have been rapid advances in instrumental design, experimental methods, and theory together with contributions from computational chemistry and gas‐phase ion chemistry, which have diversified the range of potential applications of contemporary IMS techniques. Whilst IMS‐mass spectrometry (IMS‐MS) has recently been recognized for having significant research/applied industrial potential and encompasses multi‐/cross‐disciplinary areas of science, the applications and impact from decades of research are only now beginning to be utilized for “small molecule” species. This review focuses on the application of IMS‐MS to “small molecule” species typically used in drug discovery (100–500 Da) including an assessment of the limitations and possibilities of the technique. Potential future developments in instrumental design, experimental methods, and applications are addressed. The typical application of IMS‐MS in relation to small molecules has been to separate species in fairly uniform molecular classes such as mixture analysis, including metabolites. Separation of similar species has historically been challenging using IMS as the resolving power, R, has been low (3–100) and the differences in collision cross‐sections that could be measured have been relatively small, so instrument and method development has often focused on increasing resolving power. However, IMS‐MS has a range of other potential applications that are examined in this review where it displays unique advantages, including: determination of small molecule structure from drift time, “small molecule” separation in achiral and chiral mixtures, improvement in selectivity, identification of carbohydrate isomers, metabonomics, and for understanding the size and shape of small molecules. This review provides a broad but selective overview of current literature, concentrating on IMS‐MS, not solely IMS, and small molecule applications. © 2012 Wiley Periodicals, Inc., Mass Spec Rev 32:43–71, 2013     

Accurate representation of interference colours (Michel–Lévy chart): from rendering to image colour correction

Here a work flow towards an accurate representation of interference colours (Michel‐Lévy chart) digitally captured on a polarised light microscope using dry and oil immersion objectives is presented. The work flow includes accurate rendering of interference colours considering the colour temperature of the light source of the microscope and chromatic adaptation to white points of RGB colour spaces as well as the colour correction of the camera using readily available colour targets. The quality of different colour correction profiles was tested independently on an IT8.7/1 target. The best performing profile was using the XYZ cLUT algorithm and it revealed a ΔE₀₀ of 1.9 (6.4 no profile) at 5× and 1.1 (8.4 no profile) at 100× magnification, respectively. The overall performance of the workflow was tested by comparing rendered interference colours with colour‐corrected images of a quartz wedge captured over a retardation range from 80–2500 nm at 5× magnification. Uncorrected images of the quartz wedge in sRGB colour space revealed a mean ΔE₀₀ of 12.3, which could be reduced to a mean of 4.9 by applying a camera correction profile based on an IT8.7/1 target and the Matrix only algorithm (ΔE₀₀ < 1.0 signifies colour differences imperceptible by the human eye). ΔE₀₀ varied significantly over the retardation range of 80–2500 nm of the quartz wedge, but the reasons for this variation is not well understood and the quality of colour correction might be further improved in future by using custom made colour targets specifically designed for the analysis of high‐order interference colours.     

On deformation and tearing of stiffened and un-stiffened square plates subjected to underwater explosion—a numerical study

In modern combat operations warships can be subjected to underwater blast loads capable of causing considerable structural damage. Research in the field of underwater explosion effects on structures has seen systematic developments since world war-I (WW-I) with the increased awareness that the possible underwater explosions and threats from the hunter killer “U” boats could now be countered. Most of the earlier investigations were conducted by military and these were classified. Cole [1] established empirical relations to model the underwater explosion (UNDEX) loading, which were the outcome of numerous experimental investigations done by the military agencies. In the present study the UNDEX load profile has been modeled as an exponentially decaying shock wave, which varies spatially and transiently. The failure modes in high strength (HS) and WELDOX Steel rectangular plates was predicted using an elasto-plastic model with isotropic hardening, strain rate effects and fracture criterion under clamped edge conditions. These models were implemented in the nonlinear finite element code ABAQUS/Explicit. The present study predicts and establishes the failure modes using a 3D FE analysis.     

Scanning Electron Microscopy (SEM) and Light Microscopy (LM)‐based Palyno‐morphological views of Solanaceae in Western Himalaya

In this study, plants belonging to family Solanaceae growing in Western Himalaya region have been observed palynologically under Light Microscope and Scanning electron microscope. Present investigation comprises of 10 genera and 23 species, namely, Atropa acuminata, Capsicum decoraticus, Capsicum frutescens, Cestrum aurantiacum, Cestrum diurnum, Cestrum nocturnum, Datura alba, Datura innoxia, Datura stramonium, Hyoscymus niger, Lycopersicon esculentum, Nicotiana rustica, Nicotiana tabacum, Petunia alba, Petunia hybrida, Solanum erianthum, Solanum melongena, Solanum miniatum, Solanum pseudocapsicum, Solanum surratense, Solanum tuberosum, Withania coagulans, Withania somnifera. Solanaceae is a eurypalynous family. Grains are usually Tricolporate and Tetracolporate, radially symmetrical, isopolar, prolate‐spheroidal to oblate‐spheroidal to oblate‐spheroidal to subprolate to per prolate or suboblate to oblate, size range: 8.55–72 μm, amb circular, semi‐angular or subangular, aperture drop‐type, labrum common‐type, exine usually 2 μm thick, nexine 1–1.5 μm thick. Tectum usually psilate, sexine reticulate, granulate or striato‐reticulate, with obscure pattern, sexine 1–2 μm thick, nexine 1–1.5 μm thick, and intine 0.5–1 μm thick. Most striking variation has been found in the shape class, aperture‐type, and tectal surface. Based on these characters, taxonomic keys have been made for correct identification of members in Solanaceae. However, the grains of this family are usually tricolporate and have direct relationship with certain members of the family Scrophulariaceae. Palyno‐morphological characters of family Solanaceae have been studied for the first time in Western Himalayan region of Pakistan. These palyno‐morphological characters are significant for identification of the members of family Solanaceae.     

In vivo second‐harmonic generation and ex vivo coherent anti‐stokes raman scattering microscopy to study the effect of obesity to fibroblast cell function using an Yb‐fiber laser‐based CARS extension unit

Nonlinear microscopy techniques are being increasingly used to perform in vivo studies in dermatology. These methods enable us to investigate the morphology and monitor the physiological process in the skin by the use of femtosecond lasers operating in the red, near‐infrared spectral range (680–1,300 nm). In this work we used two different techniques that require no labeling: second harmonic generation (SHG) for collagen detection and coherent anti‐Stokes Raman scattering (CARS) to assess lipid distribution in genetically obese murine skin. Obesity is one of the most serious public health problems due to its high and increasing prevalence and the associated risk of type 2 diabetes and cardiovascular diseases. Other than these diseases, nearly half of patients with diabetes mellitus suffer from dermatological complications such as delayed wound healing, foot ulcers and several other skin changes. In our experiment we investigated and followed the effects of obesity on dermal collagen alterations and adipocyte enlargement using a technique not reported in the literature so far. Our results indicate that the in vivo SHG and ex vivo CARS imaging technique might be an important tool for diagnosis of diabetes‐related skin disorders in the near future. Microsc. Res. Tech. 78:823–830, 2015. © 2015 Wiley Periodicals, Inc.     

Self‐assembled monolayers of DNA on cysteamine modified Au(111) surface: Atomic force microscopy study

The λ‐DNA molecules self‐assemble on cysteamine‐modified gold (111) surface to form flat‐lying self‐assembled monolayers (SAMs). The formation kinetics of such DNA SAMs is studied by atomic force microscopy (AFM). AFM results show that DNA molecules do not arrange themselves on cysteamine‐modified gold (111) surface into a well‐ordered monolayer. It is also found that the surface density of DNA monolayer does not increase as the DNA concentration increases. The high temperature of DNA solution and the immersing in ultrapure water produce some obvious DNA bundles. Whereas divalent cations in DNA solution result in the formation of more compact DNA films. The obtained information may be useful for practical application of the DNA films and further theoretical studies. Microsc. Res. Tech., 2009. © 2009 Wiley‐Liss, Inc.     

Recent developments of proton‐transfer reaction mass spectrometry (PTR‐MS) and its applications in medical research

Proton‐transfer reaction mass spectrometry (PTR‐MS) allows for real‐time, on‐line determination of absolute concentrations of volatile organic compounds (VOCs) with a high sensitivity and low detection limits (in the pptv range). The technique utilizes H₃O⁺ ions for proton‐transfer reactions with many common VOCs while having little to no reaction with any constituents commonly present in air. Over the past decades, research has greatly improved the applications and instrumental design of PTR‐MS. In this article, we give an overview of the development of PTR‐MS in recent years and its application in medical research. The theory of PTR‐MS and various methods for discriminating isobaric VOCs are also described. We also show several specialized designs of sample inlet system, some of those may make PTR‐MS suitable for the detection of aqueous solution and/or non‐volatile samples. © 2012 Wiley Periodicals, Inc., Mass Spec Rev 32:143–165, 2013     

Descriptive studies on the tongue of two micro‐mammals inhabiting the Egyptian fauna; the Nile grass rat (Arvicanthis niloticus) and the Egyptian long‐eared hedgehog (Hemiechinus auritus)

The current study aimed to describe the anatomical features of the tongues of two micro‐mammals common in the Egyptian fauna; the Nile grass rat (Arvicathis niloticus), and the Egyptian long‐eared hedgehog (Hemiechinus auritus). The tongues of five adult individuals of each species were excised and processed histologically, histochemically, and morphometrically. Statistical analysis comparing the relative tongue length in both species showed that there was a significant difference, which may correlate with the difference in feeding preferences. Grossly, the Nile grass rat has a dorsal lingual prominence with bifurcated apex while, the long‐eared hedgehog has a median slight elevation with rounded apex. Numerous forms of mechanical and gustatory papillae are scattered along the lingual dorsal epithelium. The histochemical detection of keratin by Holland's trichrome stain showed an intense expression in the case of A. niloticus and mild expression in H. auritus. The framework of the tongue (entoglossum) is supported by either a core of cartilage in H. auritus or bone in A. niloticus which incorporated in the lingual root. The lingual glands also showed marked variation, the Nile grass rat exhibit dense populations of mucous‐secreting glands and lesser populations of serous‐secreting glands, the contrary is true in H. auritus. In conclusion, the micro and macro‐anatomical features of the tongues of both species showed adaptive changes to accommodate the feeding lifestyle. Such type of studies using mammals from different phylogenetic traits and almost have different feeding preferences provide answers to many research questions related to tongue evolution among mammalian vertebrates.     

The morphology of the pineal gland of the yellow‐toothed cavy (Galea Spixii Wagler, 1831) and red‐rumped agouti (Dasyprocta leporina linnaeus, 1758)

The pineal gland is an endocrine gland found in all mammals. This article describes the morphology of this important gland in two species of Caviideae, namely the yellow‐toothed cavy and the red‐rumped agouti. Ten adult animals of the two species used in current analysis were retrieved from the Center for the Multiplication of Wild Animals (CEMAS/UFERSA) and euthanized. The glands were removed and photographed in situ and ex situ. They were fixed in a paraformaldehyde solution 4% or glutaraldehyde 2.5% solution and submitted to routine histological techniques respectively for light and scanning electron microscopy. Macroscopically, the pineal gland with its elongated structure may be found between the cerebral hemispheres facing the rostral colliculi. Microscopically, pinealocytes and some glia cells were predominant. Contrastingly, to the cavy's pineal gland, a capsule covered the organ in the agouti, with the emission of incomplete septa to the interior, which divided it into two lobules. Light and scanning electron microscopes failed to show calcareous concretions in the pineal gland. Based on the topography of the cavy's and agouti's pineal gland, it may be classified as supra‐callosum and ABC type. Microsc. Res. Tech. 78:660–666, 2015. © 2015 Wiley Periodicals, Inc.     

A descriptive study to provide evidence of the teratogenic and cellular effects of sibutramine and ephedrine on cardiac‐ and liver‐tissue of chick embryos

Exposure to drugs during pregnancy is a major concern, as some teratogenic compounds can influence normal foetal development. Although the use of drugs during pregnancy should generally be avoided, exposure of the developing foetus to teratogens may occur unknowingly since these compounds may be hidden in products that are being marketed as “all natural.” The aim of the current study was to investigate the possible teratogenic and cellular effects of sibutramine—a serotonin‐norepinephrine reuptake inhibitor used in the treatment of obesity—on the heart and liver tissue of chick embryos. Ephedrine was used as a positive control. The chick embryo model was chosen because it has been used in studying developmental and experimental biology and teratology with great success. The embryos were exposed to three different concentrations of sibutramine and ephedrine respectively. The results obtained revealed that both compounds exhibited embryotoxicity when compared to the control groups. Liver and heart tissue of the exposed embryos was severely affected by these compounds in a dose‐related manner. Morphology similar to that of muscle dystrophy was observed in the heart, where the muscle tissue was infiltrated by adipose and connective tissue. Severe liver steatosis was also noted. A more in‐depth investigation into the molecular pathways involved might provide more information on the exact mechanism of toxicity of these products influencing embryonic development. Microsc. Res. Tech. 78:737–746, 2015. © 2015 Wiley Periodicals, Inc.