A polychrome stain for conventionally fixed paraffin-embedded woody plant tissues

A method for the differential staining of conventionally fixed paraffin-embedded woody plant tissue is described. A five-component stain combination is used with Bismarck Brown, included to avoid the stain variability, precipitation, and overstaining problems often encountered when using safranin.     

A new liquid crystal color calibration technique using neural networks and median filtering

This study has developed a new liquid crystal calibration technique using Neural networks with median filtering and applied this technique to heat transfer measurements. To verify the validity of this new measurement technique, the local Nusselt numbers on a flat plate surface subjected to an axisymmetric impinging jet were measured and compared with the results by the conventional Hue-temperature calibration technique under the same conditions. Because the Neural networks predict the non-linear relations between temperatures and corresponding R, G, B values, Neural networks-median filtering calibration technique can utilize a much wider color band in the experiment than the Hue-temperature calibration technique, resulting in a significant reduction in the experimental time.     

A new technique for imaging hard tissue by photothermal radiometric microscopy

Thermal wave imaging of hard tissue is demonstrated for the first time using a technique described as photothermal radiometric (PTR) microscopy. Images of human bone and whale dentine suggest that the thermal wave image reveals variations in tissue density and can provide similar information to microradiography or backscattered electron imaging, to which it is now an alternative requiring a minimum of sample preparation.     

Uranyl sulphate: A new negative stain for electron microscopy

Uranyl sulphate is a negative stain of high quality for electron microscopy of macromolecules below their isoelectric point. The stain results in good contrast and high resolution as demonstrated by optical diffraction of periodic structure. Analysis of scanning transmission electron microscopic data reveals that uranyl sulphate is lower in background noise level than uranyl acetate and is dramatically more resistant toward granularization upon continued exposure to electron irradiation. Electron microscopic images of most macromolecules contrasted with uranyl sulphate were indistinguishable from those obtained with uranyl acetate. However, electron microscopic images of Reo virus contrasted with uranyl sulphate are always readily distinguished from those obtained with uranyl acetate.     

A new technique for making plant epidermal imprints using various domestic adhesives

A simple, quick and easy method for making leaf surface imprints for microscopic studies by using cheap and easily available non-toxic domestic adhesives is described. The most satisfactory results were obtained, in order of preference, by using ‘Quickfix’, ‘Stickfast’, ‘Fevicol’, ‘D.P.X. (mountant)’, ‘Camel paste’, ‘Cello-tape’ and ‘Araldite’. These were used on the epidermis of vegetative and floral organs of a number of plants (living and dried). A semi-transparent film was allowed to dry, which was then stripped off and mounted on a clean slide. This film records very fine structural details which are evident from the photomicrographs presented. With the help of this technique, the form, distribution and orientation of stomata, size of guard cells and their movement, size of stomatal pores, stomatal development, cell-wall nature, stomatal frequency and indices and venation pattern can easily be studied. Repeated imprints can be made from the same surface of an organ. This method should be of great use to plant morphologists and anatomists.     

A new approach for semiconductor parameter extraction using cathodoluminescence and artificial neural networks

In this paper, a new parameter extraction technique that jointly extracts four semiconductor-related parameters from theoretical/experimental cathodoluminescence data collected as a function of electron-beam energy is presented. The extraction technique is based on feed-forward artificial neural networks (ANN) where the ANN is trained to learn the inherent relationship between the input parameters (absorption coefficient α, diffusion length L, dead layer thickness Zt, and relative quantum efficiency Q) and the output parameter (CL intensity versus electron beam energy). After the training of the ANN, it is possible to observe the reverse process and extract the four parameters from any CL curve using an exhaustive search method. One of the main advantages of the proposed method is that the optimum set of values for the four parameters (α, L, Zt, Q) are obtained because the exhaustive search is performed in the search space spanned by all four parameters. Computational results on an n-type GaAs free defect semiconductor sample show that a unique set of parameter values with errors less than 5.5% from the nominal values can be obtained for each set of the experimental data points using the proposed algorithm.     

A new iterative near-field coherent subspace method for rub-impact fault localization using AE technique

Acoustic emission (AE) localization is an important method to detect defects in bearing of rotatory machine for faults maintenance. However, only the faults near the sensor array can be detected due to severe attenuation in the recorded AE signals. Therefore, we propose a highly reliable new Iterative near-field Coherent subspace method (IN-CSM) for multiple rub-impact faults localization. The proposed approach contains four improved processes: Modal plate wave theory (MPWT) analysis for the multi-modes decomposition and group velocity revision; Discrete wavelet transform (DWT) for the useful narrow band extraction; Near field Multiple signal classification (N-MUSIC) method for the preliminary position estimations; the IN-CSM algorithm for the multiple coherent sources separation and the precise localizations. The simulations based on N-MUSIC and IN-CSM methods were compared by rubbing teston the test rig of rotation machinery. The results indicate that the proposed method can effectively locate multiple coherent rubbing faults at once. Thus, it is an effective analysis tool for rub-impact fault detection.     

A new diagnostic technique for asperity contact

Investigations into high frequency gear vibration have given a diagnostic technique which shows asperity interactions. Smith shocks are generated at the contacts and can be detected using high frequency accelerometers to give a measure of the number and intensity of the contacts.     

Electroless plating—A new technique for the preparation of hard tissue specimens for scanning electron microscopy

Specimens with complicated, intricate three-dimensional structures, which are otherwise difficult to coat adequately by conventional means (sputter or evaporative coating) for scanning electron microscopy, can quickly and simply be rendered conductive by electroless plating. The technique can be recommended only when studying specimens at low magnification because fine detail may be lost.     

A technique for revealing tissue embedded within resin blocks

A technique is described for revealing in fine detail large pieces of tissue still embedded within rough, scratched or partly-trimmed blocks of epoxy and other resin before sectioning. The pieces of tissue immersed in baths of oil or glycerol and illuminated by an appropriate optical system, may be photographed to provide a guide to subsequent sectioning, aiding the precise location of elements in the sections back to their position in the parent tissue, and for tracing the connections of the element between serial sections. The method has been used by the authors in sectioning for light microscopy, but could equally be used with sections for electron microscopy.     

A new electron microscope technique for the study of living materials.

In order to gain informations on the real structure of biological specimens the "wet technique" for electron microscopy has been developed. The construction and the working principle of a special microchamber are described. Applications of this technique for the investigation of blood cells, gametes and various bacteries are demonstrated by micrographs.     

Lead and uranium stain artefacts in electron microscopy: a technique for minimizing their occurrence.

A new technique is presented which significantly reduced the occurrence of artefacts by eliminating the air-stain interface when staining thin sections of biological material. It is designed for simultaneous treatment of large numbers of samples. The experiment described deals mainly with the specific staining problems encountered when using grids coated with Formvar.     

A technique for localized heating in tissue: an adjunct to tumor therapy.

Increasing evidence of the beneficial effects of hyperthermia in the treatment of tumors, particularly when combined with radiation therapy or chemotherapy, has created the need for practical methods of localizing heat in arbitrary tissue volumes. Heating superficial transplanted animal tumors in hot-water baths has been of considerable importance in research, but the method has very limited clinical application. Microwave diathermy and ultrasound diathermy are capable of greater penetration than external conduction heating, but are also generally limited to the heating of superficial tissue volumes. A more direct method for localized tissue heating is proposed: localized electric current fields produced with carefully specified electrode configurations. This technique, although often quite invasive, offers the possibility of heat localization in almost any treatment volume specified by the therapist. Variations in electrical and thermal properties of tissues can be exploited to improve the architecture of the treatment plan. Several electrode configurations are illustrated. Limitations of the technique are discussed.     

A new tracking technique for mechanical angle measurement

Resolvers and other types of sine/cosine encoders are used for measurement of mechanical angles. These devices produce quadrature signals in the form of sine and cosine of the unknown angle, and require converters to extract the angle from their signals. This paper describes a new converter based on an angle-tracking technique that employs synchronized reference and oscillatory signals. The tracking is based on quadrature PLL without using VCO, DAC, counter and look-up tables (LUT). The proposed method makes use of reference oscillatory signals to estimate the sine/cosine of the mechanical angle. The present method is simpler than the available techniques, and may be implemented easily using digital or basic analogue electronic circuitry. Beside its simplicity of implementation and its fast tracking capability, the proposed controller exhibits a good linearity and, when used with resolvers, offers the advantage of robustness to amplitude fluctuation of the transducer excitation signal. The proposed technique results were compared to a high resolution pulse encoder. This paper describes the proposed method, its simulation and experimental results.     

A new technique for the investigation of stick-slip

The stick-slip phenomenon has been investigated using an existing high frequency friction machine at very low speed. Static friction was found to vary with frequency and to approach a maximum as the length of time during which the contacting surfaces were at rest increased. This was thought to be due to a squeeze film effect leading to increasing asperity contact.     

A new technique for obtaining large platinum-carbon replicas

A problem often encountered in freeze-fracturing is that platinum-carbon replicas roll up or are broken into fragments during tissue digestion and replica washing. In replicas damaged in these ways, tissue orientation and cell identification are difficult. In order to prevent such damage, methods have been introduced of replica strengthening by coating them with plastic films (Steere, 1957; Willison & Rowe, 1980; Stolinski et al., 1983), or with an additional layer of silver or gold (Robards & Umrath, 1978; Robards & Sleytr, 1985). A disadvantage of these methods, however, is that the additional layer must be removed before the replicas can be examined under the electron microscope. Removal of the additional layer results in loss of image quality. A reinforcing plastic film may not be completely digested by the tissue solvent and will then contaminate the replica, while the silver technique requires a silver evaporation source to be present in the vacuum chamber. Instead of replica strengthening methods, some authors recommend putting replicas carrying tissues, which have been partially digested by bleach (Pearce, 1983) or chromic acid (Fetter & Costello, 1986), onto carbon-coated gold grids and then floating them on chromic acid. However, neither this method nor the replica strengthening method assure the production of large unrolled replicas. Moreover, gold grids are rather expensive.     

A new diagnostic technique for ball screw actuators

Ball screw actuators are electro-mechanical actuators that translate rotational motion to linear motion with little friction; they are used in precise engineering and particularly in aerospace applications where they replace hydraulic linear actuators. Until now, few diagnostic approaches have been developed with regard to fault detection and characterization of ball screw actuators.     

一种新型缓冲器的工艺方法

介绍了一种新的起落架缓冲器在制造过程中,对其中的难点问题进行了分析,并提出了应对措施,达到了预期效果.     

Fluorescence reactions of orcein: new applications for an old stain

The fluorescence properties of orcein are described in this paper. Under suitable exciting light, acidic solutions of orcein showed emission peaks at 587 nm (low concentration) and at 620 nm (high concentration). In fluorescence microscopy an intense orange-red emission was found in the cytoplasm and nucleoli from acetic orcein squashes of meristematic cells, as well as in the cytoplasm of Ehrlich tumour cells and in chicken erythrocyte nuclei. When semithin sections of Epon-embedded tissues were treated with orcein, a strong fluorescence reaction (orange-red) appeared in starch granules, cell walls, elastin, collagen, reticulin, keratohyalin, chromatin and mucin. Cytofluorometric measurements of orcein-stained chromatin revealed an emission peak at 585 nm with a shoulder at 620 nm. These spectroscopic and microscopical results suggest the possibility of employing orcein as a fluorochrome.