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The synthesis of stoichiometric two-dimensional (2D) transition-metal dichalcogenides (TMDC) over large areas remains challenging. Using a combination of X-ray diffraction and X-ray absorption spectroscopy, we demonstrate the advantages of using a thin amorphous layer of S-rich MoS2(MoS4in this paper) for the growth of well-ordered crystalline MoS2films via annealing at 900 °C. In contrast to the crystallization of stoichiometric amorphous MoS2, the crystallization of the as-deposited amorphous MoS4phase shows the strong preferred ordering of layered MoS2on a Si/SiOxnontemplating substrate with the dominant (002) crystallographic plane and accompanying Kiessig fringes, which indicate the improved crystallinity of the MoS2layers. A similar effect can only be achieved by the templated crystallization of an amorphous MoS2thin film deposited on a c-plane sapphire substrate. We suggest that the crystal growth improvement originates from the lower coordination number (CN) of the Mo atoms in the MoS4amorphous phase (CN = 4) in comparison with that of amorphous MoS2(CN = 6) and the gradual release of free sulfur atoms from the thin film during crystallization.

A newly developed unique combination of direct microscopic and calorimetric measurements was used to study the crystal growth in amorphous selenium (a-Se) thin films (500 nm) deposited on Kapton tape and aluminum foil. The crystal growth rates (ur) microscopically determined in the 65–110 °C temperature range were similar to those for bulk selenium glass. The crystal growth kinetics was described in terms of the screw dislocation model with implemented temperature dependences of the growth activation energy EGand Ediger’s decoupling parameter ξ. Extensive analysis of the literature data on the crystal growth rates in thin selenium films revealed the dominant effect of the number and distribution of the dangling bonds of the [Se]nchains adjacent to the film/substrate interface. The seemingly scattered ur– Tliterature data were found to be consistent when the influences of impurities, substrate quality, illumination, and deposition conditions were accounted for. The macroscopic manifestation of the crystal growth in selenium thin films was observed by means of differential scanning calorimetry (DSC)─the corresponding activation energies were similar to the EGvalues determined by optical microscopy; the Avrami equation with the implemented ur– Tdependence was able to accurately describe the macroscopic DSC data. Additional DSC measurements for the selenium thin film scraped off the white glass substrate have shown that the above-Tgannealing of such a material suppresses the crystallization, which can be interpreted as the evidence of the dominant growth from the mechanically activated crystallization centers.

Five species of the genus Vinciguerria (namely †V. macarovicii, †V. praeattenuata, †V. talgiensis, †V. obscura, and †V. merklini) were described and/or recorded from Romania. Most of the Eocene and Oligocene fossil species of this genus from the Central and Eastern Paratethys were later grouped in two genera (†Sytchewskia and †Eovinciguerria), mainly due to the morphology of the caudal skeleton. A systematic revision of the vinciguerrid phosichthyids from the Oligocene deposits of Piatra-Neam?, Romania (Central Paratethys) is presented herein. Based on the character analysis and relationships of the recent phosichthyid genera, we consider the genus †Eovinciguerria to be invalid and we re-establish the validity of the genus Vinciguerria for the Oligocene species. Morphological comparisons of the original material with well-preserved specimens of †V. obscura from Litencice (Czech Republic) and contemporary representatives allow us to recognize that †V. macarovicii is a synonym of †V. obscura. Moreover, †V. merklini recorded from the Oligocene deposits of Piatra-Neam? (Romania) represents a juvenile specimen of †V. obscura, contrary to what was previously postulated.

Reactivity of five reactive agents with two biopolyesters, poly (3-hydroxybutyrate) (PHB) and poly (lactic acid) (PLA), was studied in situ during processing in laboratory kneader with simultaneous recording of a melt torque. Among them only Raschig, an oligomeric carbodiimide based additive, was proven to enhance melt viscosity of both. In order to find out the most efficient level of this additive for stabilizing of both polymers and PHB/PLA (70/30 w/w) blend, different concentrations were studied by means of melt torque monitoring, rheology time tests and gel permeation chromatography. Results showed the same trend for neat polymers and their blend. Addition of more than 0.5 % wt. did not have any further positive effect on molecular weight or complex viscosity of the melt. Higher amount is not consumed during the reaction and is left in the sample. Therefore, this amount was used for processing stability studies on PHB/PLA blends by subsequent extrusion cycles. Melt volume-flow rate of extruded samples was obtained and results showed lower values for all stabilized blends comparing to the first extrusion sample of non-stabilized blend. At the same, stability of the blends is secured up to the third extrusion cycle.

Presented work deals with the development of bio-source and biodegradable composite material for 3D printing. Polymer blend based on poly (3-hydroxybutyrate) (60 wt%) and poly (lactic acid) (25 wt%) plasticized by tributyl citrate (15 wt%) was used as a matrix. This base blend was filled with 10 vol% of kaolin or limestone. Zinc stearate was used for the surface treatment of the limestone samples. The mechanical and thermal properties of the composites, as well as their behavior during 3D printing process, were compared with unfilled blend and commercial poly (lactic acid) based 3D printing filament. Warping behavior, one of the main problems of 3D printing materials, was studied by means of warp coefficient. Cross-sections of specimens 3D printed under the same processing conditions were observed by the optical microscope. In the case of composite samples, individual filaments were separated. Despite the separation, composites filled with kaolin and with surface treated limestone exhibited satisfying mechanical properties. Scanning electron microscopy analysis confirmed good particle distribution of the samples with kaolin and surface treated limestone. No significant particle agglomerates were formed in the composites with limestone proving good dispergation ability of zinc stearate. Thermogravimetric analysis and Differential scanning calorimetry analysis showed no degradable effect of the used fillers on base polymer matrix. Observed results indicate that kaolin and surface treated limestone are suitable fillers for the bio-source composites used for 3D printing.

A novel joint microscopy–calorimetry technique pioneered in the present thin film research was used to investigate the influence of the substrate type on the crystal growth in (GeS2)0.1(Sb2S3)0.9thin films crystallizing from the free surface. The explored temperature ranges were 205–285 and 210–350 °C for microscopy and calorimetry, respectively. Identical temperature dependences of the macroscopic and microscopic crystal growth rates, crystal growth activation energies (decreasing from 333 to 277 kJ·mol–1), and values of the Ediger’s decoupling parameter (decreasing from 0.63 to 0.55) were obtained for as-deposited thin films on Kapton as well as white glass substrates, confirming the negligible influence of the substrate nature. However, both types of as-deposited films exhibited markedly accelerated crystal growth compared to the powdered thin film (scraped-off of the substrate), for which the formation rate of the crystalline phase was practically identical to the native behavior of bulk glass. This unambiguously confirms the marked influence of the crystal-growth-accelerating internal stresses being built up during the heating of the thin film firmly attached to the substrate, where each of the two materials has a different thermal expansion coefficient. The unmatched accuracy and resolution of the joint microscopy–calorimetry approach were demonstrated, with similar subtle intrinsic trends in the crystal growth behavior being recognized by both techniques. Future prospects of the simultaneous in situ polarization microscopy measurements of crystal growth in the as-deposited thin films were introduced and discussed.

Hyperkinetic movements are generally described as involuntary movements. They can be focal, affecting just one group of muscles in limbs, trunk or face, or generalised causing the whole body to be affected. We choose to classify them based on their clinical appearance as that can be the primary complain of the owner and the only clinical sign observed. Many of these disorders have a genetic component and breed predisposition, or may be a clinical manifestation of an underlying neurological disease. Therefore the aim of this article is to provide brief information regarding these hyperkinetic disorders classified by their clinical appearance and possibly by their breed predisposition.

We present photoelectrochemical results for anodic TiO2nanotube layers grown with different diameter sizes (21, 35, 56, and 95 nm) with a thickness of approximately 560 nm using a novel anodization protocol. These tube layers were utilized as highly ordered n-type conductive scaffold for the inorganic chromophore Sn–S–Se. While downscaling the nanotube diameter significantly increased the number of nanotubes per square unit (from 5.6 × 109to 7.2 × 1010pcs/cm2) and thus the active surface area increased as well, we found that the photoelectrochemical response in the UV light was identical and thus independent of the TiO2nanotube diameter in the range of nanotube diameters from 35 to 95 nm. Further, we demonstrate that a heterostructured photoelectrochemical cell consisting of TiO2nanotubes sensitized with crystalline Sn–S–Se chromophore showed higher photocurrent density (from 6 to 32 μA/cm2for the wavelength of 460 nm) with increasing nanotube diameter size. Upon detailed SEM analyses it was revealed that Sn–S–Se was infilled in all nanotube layers approximately to one-third of the thickness. Therefore, this photocurrent increase with increasing tube diameter can be ascribed to better interfacial contact (and improved charge transport) facilitated between the chromophore and nanotube walls.

The fossil trachinid species Trachinus minutus (Jonet, 1958) from the Paratethys area is represented by numerous specimens, but none of them is larger than ca. 35 mm. Newly collected material from the Hermanowa locality allows a better interpretation of the morphological changes that occur during ontogeny to be described from a size of about 10 mm to the largest preserved stage. These changes are connected with the origin and changes in the morphology of selected skull bones, the origin of fins and the number of fin rays. In general, it is possible to say that the smallest preserved specimen shows a well-developed skull roof, otic part, angulo-articular, dentary, maxillae, anterior part of the premaxillae, preopercles, cleithra, first four spines of the first dorsal fin, and ventral fin spines. The ethmoid, together with the ectopterygoid, opercles and corpus quadrati are more or less recognizable, but obviously in the initial stages of their morphogenesis. There are about 22 vertebrae preserved in the vertebral column, with decreasing visibility further posteriorly (the caudal portion of the column was probably not ossified sufficiently and therefore is not recognizable). Other elements are not yet developed or distinctive. During later stages of ontogeny, the ossification of the skull and postcranial skeleton continue, the fifth spine of the first dorsal fin appears, and the anal and second dorsal fins start to form. The morphology of some bones changed rapidly during ontogeny and their appearance is conditional on the particular age of the specimen. These data are compared with our knowledge of Recent trachinids.

Despite extensive efforts, the principal sites of productive HIV-1 entry in different target cells─plasma membrane (PM) vs endosomes─remain controversial. To delineate the site(s) of HIV-1 fusion, we implemented a triple labeling approach that involves tagging pseudoviruses with the fluid-phase viral content marker, iCherry, the viral membrane marker, DiD, and the extraviral pH sensor, ecliptic pHluorin. The viral content marker iCherry is released into the cytoplasm upon virus–cell fusion irrespective of the sites of fusion. In contrast, the extent of dilution of the membrane marker upon fusion with the PM (loss of signal) vs the endosomal membrane (no change in punctate DiD appearance) discriminates between the principal sites of viral fusion. Additionally, ecliptic pHluorin incorporated into the viral membrane reports whether virus fusion occurs in acidic endosomes. Real-time single virus imaging in living HeLa-derived cells, a CD4+ T-cell line, and activated primary human CD4+ T-cells revealed a strong (80–90%) HIV-1 preference for fusion with endosomes. Intriguingly, we observed HIV-1 fusion only with pH-neutral intracellular vesicles and never with acidified endosomes. These endocytic fusion events are likely culminating in productive infection since endocytic inhibitors, such as EIPA, Pitstop2, and Dynasore, as well as a dominant-negative dynamin-2 mutant, inhibited HIV-1 infection in HeLa-derived and primary CD4+ T-cells. Furthermore, the inhibition of endocytosis in HeLa-derived cells promoted hemifusion at the PM but abrogated complete fusion. Collectively, these data reveal that the primary HIV-1 entry pathway in diverse cell types is through fusion with pH-neutral intracellular vesicles.

Mannitol is an alcoholic sugar that is commonly used in the food industry. It is a white, odorless crystalline powder. Its melting temperature is about 168 °C. It is possible to be used also for the accumulation of energy in the heat exchangers based on oils. On its basis is sold a product PlusICE A164 of company PCM Products Ltd. (T = 164 °C, cp = 2.42 kJ.K-1 kg-1). Thermal properties of the material in both, solid and liquid phase were investigated for this purpose in terms of potential applications. Temperature dependence of thermal parameters (thermal diffusivity, thermal conductivity, and specific heat) were determined using a transient (step-wise) method. Fractal model of heat transport was used for the determination of thermal parameters. This model is independent on the geometry and on the type of the sample heating, and includes heat losses too. The experiment confirms the phase change temperature about 168 °C.

Raman microspectroscopy in conjunction with multivariate statistical analysis is a powerful technique for label-free classification of live cells based on their molecular composition, which can be correlated to variations in protein, DNA/RNA, and lipid macromolecules. We apply this technique in vitro, to discriminate between normal mouse ovarian surface epithelial (MOSE) cells and spontaneously-transformed ovarian surface epithelial (STOSE) cells, which are derived from the MOSE cells and are a model for high-grade serous ovarian cancer. The Raman spectra collected from individual cells undergo initial preprocessing (background subtraction, normalization and noise reduction) to yield true Raman spectra representative of the cells for subsequent statistical analysis. Using Principal Component Analysis (PCA) followed by Linear Discriminant Analysis (LDA) yields a separation of the cells into the two groups (MOSE and STOSE). This classification model has a sensitivity and specificity of 92% and 85%, respectively, after treatment of the cells to bring them into cell cycle synchrony. The main source of this separation is correlated with the increased nucleic acid content in the malignant OSE cells. As expected, a lower accuracy of 72% is obtained with asynchronous MOSE and STOSE cell populations. These results are expected to have a positive impact on the future development of improved strategies for early detection and therapeutics related to ovarian cancer.

The Pravcická brána Arch (PBA) is formed in the Cretaceous sandstones of the Bohemian Cretaceous Basin (NW Bohemia, Czech Republic). It represents the largest sandstone arch and one of the frequently visited natural heritage sites in Europe. The arch, currently in a mature stage of development, suffered from increased anthropogenic impacts over the past decades (until 1982 from the free access of visitors; effects of on-going atmospheric pollution). The impacts of these degradation factors upon the natural processes which will influence the further developments of the PBA are discussed, based on previous detailed surveys and monitoring. The PBA is presented as a self-organizing hierarchical system, exhibiting complex non-linear behaviours.

Results of a superposed epoch (SPE) analysis of occurrence of phase scintillation and cycle slips at high latitudes keyed by arrival times of high-speed solar wind streams (HSS) and interplanetary coronal mass ejections (ICME) for years 2008 to 2012 are presented. Phase scintillation index σΦis obtained in real time from L1 signal recorded at the rate of 50 Hz by specialized global positioning system (GPS) ionospheric scintillation and total electron content (TEC) monitors (GISTMs) deployed as a part of the Canadian High Arctic Ionospheric Network (CHAIN). The phase scintillation, mapped as a function of magnetic latitude and magnetic local time, occurs predominantly on the dayside in the cusp and in the nightside auroral oval. The scintillation occurrence peaks on days of HSS or ICME impacts at the Earth's magnetosphere and tapers off a few days later, which is similar to day-to-day variability of geomagnetic activity and riometer absorption at high latitudes. ICMEs that are identified as magnetic clouds are significantly more geoeffective than HSSs and ICMEs with no or weak magnetic cloud characteristics. On their arrival day, magnetic clouds result in higher occurrence, and thus probability, of scintillation in the nightside auroral zone. The SPE analysis results are used to obtain cumulative probability distribution functions for the phase scintillation occurrence that can be employed in probabilistic forecast of phase scintillation at high latitudes.

A new species of the family Bramidae, Paucaichthys elamensis sp. nov., is described from the Oligocene of the Elam locality (Iran). The new species is represented by a single juvenile specimen that is morphologically strongly similar to the holotype of P. neamtensis from Romanian Carpathians, but differs in its morphometric and meristic features as well as its dynamics of ossification.

The poem "Purple Room," by Jana Prikryl is presented. First Line: You dwelled in an apartment at the top of an offi ce building; Last Line: a slow waltz with an octopus who liked me.

The poem "Midwood 20," by Jana Prikryl is presented. First Line: It fi nally happened, I fell asleep puzzling; Last Line: examined closely, it is too close, did I think that would let me off.

The poem "Another Time," by Jana Prikryl is presented. First Line: It started another time in me; Last Line: that dropped their leaves on top of leaves.

The poem "A Procedure," by Jana Prikryl is presented. First Line: AI had some minor surgery on Monday; Last Line: to sleep I count three things that weren't completely intolerable that day.

The Eocene deposits from the Staré Mesto locality (Frýdlant Formation, Subsilesian Unit) provided fossil fish remains, which can be assigned to two elasmobranch taxa: the eagle ray Leidybatis jugosus and the shark Centrophorus sp. The specimens are represented by associated dental plates and isolated teeth. This is the first record of L. jugosus in the Czech portion of the Western Carpathians and is thus the second record for the entire Carpathian area. Presence of the taxon confirms the Eocene age of the deposits. The common occurrence with genus Centrophorus suggests sedimentation in deeper conditions (> 200 m). Other material (obtained by microvertebrate preparation technique), isolated dermal denticles and calcified cartilage prisms, are described using open nomenclature (Myliobatoidei indet. and ?Myliobatiformes indet., respectively).

Despite the development of second-generation antipsychotic drugs, treatment-resistant symptoms still represent a serious problem in schizophrenia. The aim of the present article was to review studies with repetitive transcranial magnetic stimulation for negative symptoms of schizophrenia and draw conclusions for clinical decision making.

The article offers information on a study on the high-latitude ionosphere in the Arctic and Antarctic, conducted by the Canadian High Arctic Ionospheric Network, an array of ten Global Positioning System (GPS) receivers and six Canadian Advanced Digital Ionosondes. Similar arrays are said to be complemented by the chain array of GPS Ionospheric Scintillation and TEC Monitors in northern Europe. The benefits of studying ionospheric scintillation-causing irregularities are highlighted.

A specimen of the Early Jurassic actinopterygian fish Pachycormus sp. from the Lower Jurassic Posidonia Shale of Germany has a well preserved filling of the alimentary canal. The region interpreted as the stomach contains numerous hooklets that can be referred to the coleoid cephalopod Phragmoteuthis Mojsisovics, 1882. The presence of arm hooklets clearly demonstrates predation on coleoid cephalopods by actinopterygian fishes.

In this study, we use measurements from over 4,735 globally distributed Global Navigation Satellite System receivers to track the progression of traveling ionospheric disturbances (TIDs) associated with the 15 January 2022 Hunga Tonga‐Hunga Ha'apai submarine volcanic eruption. We identify two distinct Large Scale traveling ionospheric disturbances (LSTIDs) and several subsequent Medium Scale traveling ionospheric disturbances (MSTIDs) that propagate radially outward from the eruption site. Within 3,000 km of epicenter, LSTIDs of >1,600 km wavelengths are initially observed propagating at speeds of ∼950 and ∼555 ms−1, before substantial slowing to ∼600 and ∼390 ms−1, respectively. MSTIDs with speeds of 200–400 ms−1are observed for 6 hrs following eruption, the first of which comprises the dominant global ionospheric response and coincides with the atmospheric surface pressure disturbance associated with the eruption. These are the first results demonstrating the global impact of the Tonga eruption on the ionospheric state. The 2022 Tonga oceanic volcanic eruption and resulting tsunami was an incredibly impulsive and high energy event. Such events can generate strong pressure waves in the atmosphere that can propagate up into the Earth's ionosphere and modulate the plasma therein. Using every available Global Navigation Satellite System (GNSS) receiver from a global network of over 4,735 instruments, we were able to track the propagation of these waves from the Tonga eruption site around the planet. We show that an initial shock front at speeds of up to 950 ms−1strongly perturbs the ionospheric electron density near the eruption site and within a narrow extended region to the North, while smaller, slower waves originating from the eruption make up the strongest ionospheric response at distances far away from the eruption region. Small scale ionospheric waves continue to be produced near the eruption for up to 6 hrs after the eruption began. These waves were tracked from the eruption to over 20,000 km from the epicenter and could very well have persisted beyond the 1 day studied here. Highly directional Large Scale traveling ionospheric disturbances (LSTIDs) are generated from the Tonga Eruption at initial speeds up to 950 m/s and propagate potentially as far as 20,000 kmOutside the local area of the eruption, Medium Scale traveling ionospheric disturbances (MSTIDs) coincident with the surface pressure wave form the dominant ionospheric responseSecondary MSTIDs continue to be produced in the vicinity of the eruption for up to 6 hr following the event Highly directional Large Scale traveling ionospheric disturbances (LSTIDs) are generated from the Tonga Eruption at initial speeds up to 950 m/s and propagate potentially as far as 20,000 km Outside the local area of the eruption, Medium Scale traveling ionospheric disturbances (MSTIDs) coincident with the surface pressure wave form the dominant ionospheric response Secondary MSTIDs continue to be produced in the vicinity of the eruption for up to 6 hr following the event

The remediation of soil cut slope instability in Texas has traditionally been achieved using conventional methods. However, in early 2002 an alternative approach was taken to achieve the remediation of a failed slope using tyre bales, which are blocks of compressed whole post-consumer tyres. This paper describes the construction of the repair, the comparative retrospective analysis that was carried out to determine the likely performance of such slope repairs, and visual observations made around two years after construction. Specific lessons are drawn from the experience gained from this work.

Crystal growth in 1 μm Se(1–y)Teythin films (for y= 0, 7, 10, and 17) deposited on the Kapton, SiO2glass, and white glass substrates was researched and quantified by means of a unique combination of direct joint microscopic and calorimetric measurements. As a general feature, the crystal growth in the Se–Te thin films deposited on a Kapton tape was very close to the native/bulk crystal growth. Deposition on the inorganic glassy substrates largely accelerated the crystal growth in the Se–Te thin films due to the build-up of internal tension originating from the large difference in thermal expansion coefficients between the film and the substrate. An additional increase in the crystal growth rate was also caused by the diffusion of Na+ions from the white glass substrate into the Se–Te films. Almost perfect correspondence was found for the activation energies of crystal growth determined by various measurement techniques (calorimetry and microscopy) and for various Se–Te sample forms (thin films, bulk glass, powdered bulk glass). A very good agreement was found also between the activation energies of viscous flow and structural relaxation at the glass transition temperature Tg. At higher temperatures, the Se–Te thin films exhibit a minor-to-moderate breach of the Stokes–Einstein law, as expressed by the value of Ediger’s decoupling parameter ξ ≈ 0.80 ± 0.05. At lower temperatures near the glass transition, the violation of the Stokes–Einstein relation deepens for the thin films with higher Te content. An explanation was proposed based on the potential interconnection between the below-Tgrelaxation kinetics and above-Tgconnectivity of the undercooled liquid domains (resulting either in changes of the effective hydrodynamic radius during the self-diffusion or in the tendency to create structural inhomogeneities via thermal fluctuations).

A long series of polar patches was observed by ionosondes and an all-sky imager during a disturbed period (Kp = 7- and IMF Bz <0). The ionosondes measured electron densities of up to 9 × 1011 m-3 in the patch center, an increase above the density minimum between patches by a factor of ˜4.5. Bands of F-region irregularities generated at the equatorward edge of the patches were tracked by HF radars. The backscatter bands were swept northward and eastward across the polar cap in a fan-like formation as the afternoon convection cell expanded due to the IMF By > 0. Near the north magnetic pole, an all-sky imager observed the 630-nm emission patches of a distinctly band-like shape drifting northeastward to eastward. The 630-nm emission patches were associated with the density patches and backscatter bands. The patches originated in, or near, the cusp footprint where they were formed by convection bursts (flow channel events, FCEs) structuring the solar EUV-produced photoionization and the particle-produced auroral/cusp ionization by segmenting it into elongated patches. Just equatorward of the cusp footprint Pc5 field line resonances (FLRs) were observed by magnetometers, riometers and VHF/HF radars. The AC electric field associated with the FLRs resulted in a poleward-progressing zonal flow pattern and backscatter bands. The VHF radar Doppler spectra indicated the presence of steep electron density gradients which, through the gradient drift instability, can lead to the generation of the ionospheric irregularities found in patches. The FLRs and FCEs were associated with poleward-progressing DPY currents (Hall currents modulated by the IMF By) and riometer absorption enhancements. The temporal and spatial characteristics of the VHF backscatter and associated riometer absorptions closely resembled those of poleward moving auroral forms (PMAFs). In the solar wind, IMP 8 observed large amplitude Alfvén waves that were correlated with Pc5 pulsations observed by the ground magnetometers, riometers and radars. It is concluded that the FLRs and FCEs that produced patches were driven by solar wind Alfvén waves coupling to the dayside magnetosphere. During a period of southward IMF the dawn-dusk electric field associated with the Alfvén waves modulated the subsolar magnetic reconnection into pulses that resulted in convection flow bursts mapping to the ionospheric footprint of the cusp.

AbstractMeasurements are presented of gold concentration in rock/soil samples by delayed neutron activation analysis using a device and method that are potentially field portable. The device consists of a polyethylene moderator and 252Cf as the source of neutrons for activating the samples and a high-purity germanium detector to measure the 412-keV gamma-ray emissions from activated gold. This information is used to extract the gold concentration in the sample. Two types of samples were investigated: (a) pure SiO2doped with a known amount of gold chloride and (b) U.S. Geological Survey standards. The former types were used to evaluate optimum device performance and to calibrate the device and method. The latter types were used to show typical system performance for the intended application (field exploration for gold deposits). It was found that the device was capable of determining gold concentrations to ~10 ppb with a turnaround time (the sum of irradiation, decay, and counting times) of ~10 days. For samples where the gold concentration was much higher (i.e., gold ore), turnaround times are ~2 days and could be shortened further by sacrificing accuracy (e.g., lessening irradiation, decay, and counting times) or by augmenting source strength.

For the case of holographic interferometry when one measures changes in position and shape of diffusely reflecting surfaces new, quite general relations determining the localization of interference fringes are derived. The important properties of fringe localization are also discussed and a useful practical solution is drawn.

A very simple method for evaluating hologram imagery in a general holographic arrangement with spherical or plane reference and reconstruction waves is proposed. For the hologram imagery approaching aberration-free case the relations providing new possibilities are introduced. The study is not restricted to plane holograms only but one can also study the imaging of objects reconstructed from volume holograms.

By introducing a double ether group, e.g. an alkoxyalkoxy-group in the aromatic structure of the 2,4-diamino-5-benzylpyrimidines the water- and lipid-solubility was clearly altered with respect to trimethoprim. A compound with enhanced activity, tetroxoprim, was further studied. Substituting oxygen in position 4 by a sulphur atom leads to interesting compounds with antibacterial activity.

A new approach using the diffraction method of linear superposition is used for the analytical description of an imperfect Fabry-Perot etalon. Derived simple relations for the transfer coefficients of a corrugated thin-film system may find a broader field of application.

A hybrid optical/digital processing scheme for measuring phase distributions is described and demonstrated. It is intended to be an alternative to interferometric methods of measuring optical path length changes in flow diagnostics and can also be used as a flow visualization technique. The processing scheme enables one to make accurate measurements of phase at arbitrary points in the image plane. The system is based on a simple coherent optical Fourier processor but incorporates three separate measurements and postdetection digital processing to eliminate extraneous parts of the signal. The addition of a holographic filter to the system enables one to measure deformation or displacement of diffusely reflecting opaque objects. The technique is demonstrated by using it to visualize the flow of an expanding compressible gas jet and to measure the optical path length through a heated plume of air.

The paper relates to hologram synthesis from 2-D transparencies. A synthetic field hologram, that is, a synthetic hologram with the diffraction efficiency unimpaired by the number of basic holograms overlapping each other on a synthetic field hologram, is presented. This hologram may be reconstructed in white light. The hologram and method of its creation can be used for making holographic land maps.

Fringe formation and localization in holographic interferometry of transparent media are discussed for configurations in which light enters the medium and is scattered back through it by an embedded diffuse object. Fringe order numbers are doubled, and the fringe localization region is translated and compressed by a factor of 2. The results are applicable to tomographic reconstruction of aerodynamic density fields around opaque test objects.