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A de-mix capable model for turbulence in compressible, variable density flows is proposed. The model is based on the Besnard-Harlow-Rauenzahn (BHR) family of models (Besnard D, Harlow F, Rauenzahn ...

Background Mobile apps such as WhatsApp have become significant resources for information and social support in times of crisis. Little is known about the role WhatsApp groups play in the context of living in conflict-affected regions. Living in such areas is associated with myriad mental health impacts, and recent studies have identified parents of young children as highly vulnerable in this regard. The study’s aim was to examine parents’ digital coping with political violence in southern Israel. Methods In-depth interviews were conducted with 21 parents of young children ( Results The findings reveal that online groups are often discussed as a shared and ubiquitous coping resource that supports mental health and well-being. Parents report they use the group to share ways to deal with the situation effectively and exchange social support, and as a space that facilitates community cohesion. Furthermore, during escalations, members perceived the group as the most trustworthy source of information. The groups’ continuous availability had drawbacks as well. Some participants pointed to digital stress caused by the fear of missing out on information, or by information overload. Conclusions Our results demonstrate the effectiveness of digital environments in helping parents cope with a collective stressor: a particularly worthy goal given that social media apps now constitute the primary online connection for most individuals. This has broad impacts on health promotion efforts for mental health issues related to political violence as well as other large-scale health crises such as the COVID-19 pandemic. Key messages • Digital environments can serve as a platform for successful coping with collective stressors. • Health practitioners should consider drawbacks when planning digital support efforts.

Background Orthotopic heart transplantation (OHT) is an end-stage treatment option for heart failure (HF). Although post-transplant diabetes (PTDM) is a well-described complication following immunosuppressive treatment, the impact on LV function post-OHT has not been evaluated. The purpose of this study was to analyse the influence of PTDM on LV function in OHT patients using conventional and speckle tracking echocardiography. Furthermore, we aimed to compare echocardiographic LV function parameters to HbA1c levels in OHT recipients with or without PTDM. Methods The study included 104 (n=77 male, mean age 51±15 years) consecutive OHT patients (PTDM n=36) examined at their routine 3-year follow-up. Blood pressure, heart rate, and HbA1c levels were recorded in conjunction with the echocardiographic examination. Results Participants with PTDM demonstrated impaired LV function measured by global longitudinal strain (p=0.002). Patients with PTDM also revealed increased septum diameter (p=0.008), and a lower diastolic EA-ratio (p=0.04) compared to the non-PTDM patients. A weak correlation between high HbA1c levels and poor LVGLS was detected (r=0.30, p Conclusion A subtle LV dysfunction, including remodelling of the heart (i.e., increased wall thickness), reduced longitudinal contractile function, and altered diastolic function, was present in OHT patients with PTDM. Our findings suggest that sub-clinical myocardial dysfunction is present in OHT patients with PTDM and may progress to clinical LV dysfunction and HF. Hence, analysing secondary cardiac effects of PTDM in OHT patients may have a therapeutic and prognostic value and could potentially influence long-term patient survival. Funding Acknowledgement Type of funding sources: None.

The mode split on disc like structures rotating in a dense fluid leads to a deviation of eigenfrequencies at high rotational speeds compared to their values in still water. Predicting eigenfrequencies correctly is essential to avoid fatigue cracks on prototype turbine runners. Analytical models for simple geometric configurations and complex numerical models using fully coupled fluid structure interaction to predict the mode split on arbitrary geometries exist. We are presenting a complementary approach of intermediate complexity applicable to arbitrary geometries. Mode shapes and modal parameters are computed by finite element analysis in still water. These mode shapes are imposed with a harmonic variation in time during an unsteady computational fluid dynamics computation. From the interaction between the flow and the modal motion, the modal force and the modal work can be computed. These can be converted into added modal mass and hydrodynamic damping and further into the shift of the eigenfrequency under rotation due to the fluid for a given mode. The tendencies of the frequencies with rotation compare reasonably well with experimental data. The numerical method can be applied to disc rotation speeds far beyond the range of experimental data revealing interesting tendencies and a phenomenological interpretation of the cause of the mode split.

Summary Many fields worldwide suffer of excessive water production and poor sweep efficiency because of conformance problems due to the existence of reservoir heterogeneities and preferential pathways for water flow. When heterogeneity contrasts are high, a permeability barrier has to be placed in water thief zones. In this paper, a new Conformance technology using thermo-associative polymers (TAPs) is presented. TAPs are polymers containing temperature-sensitive chemical moieties, called “LCST moieties” (“LCST” for “Lower Critical Solubility Temperature”). These moieties are totally hydrophilic at low temperatures and becomes hydrophobic above a threshold temperature. They can thus interact with each other, forming a three-dimensional network through hydrophobic associations. This process is thermo-reversible. By adjusting the amount of LCST moieties and the molecular weight of the polymer, strong viscosity contrasts may be obtained between low and high temperature (up to several decades). This strategy was used to develop a new family of conformance products called “thermogel” where a transition from a low viscous solution to a strong gel may be obtained upon heating. The paper presents the work performed to develop a Thermogel for a North Sea fractured chalk application. Since chalk matrix has a very low permeability (K∼1.5mD), strategy of production is to fracture and acid stimulate the formation along the well with water injection support. In this specific field case, one isolated fracture connects injection well to production well inducing a short cut between the wells. The aim of the pilot is to inject a Thermogel treatment to reduce water intake from the fracture. The paper describes the development of the product through laboratory experiments. The evaluation of the properties of different thermogels in bulk rheology and in coreflooding experiments are discussed in view of the pilot application. The main results can be listed as follows: – The new thermogel has a threshold temperature of around 40°C, that enables gelation far from the injection well, deep in the reservoir. – Coreflooding experiments in carbonate pack that mimic fracture permeability (K∼250D) have been performed. A minimum Thermogel concentration of 60 000ppm is necessary to form a gel with high blocking efficiency. – Injectivity in coreflooding experiments depends on Thermogel chemistry and on elasticity properties. – Strong face plugging when Thermogels are injected in pure matrix conditions (K=2mD) ensures that the product cannot propagate inside the matrix and will flow in fracture only. From those laboratory results, two products have been qualified for further field applications.

Surface properties of monofilaments can be tailored with radial structural gradients, which is of specific interest for technical textile applications. Radial gradients in fine (≤40 μm thick) poly(ethylene terephthalate) monofilaments have been studied with high-resolution Raman mapping and one-dimensional microbeam small-angle x-ray scattering tomography. Filaments have been melt-spun by using online and offline drawing techniques. Radial structural gradients are strongly affected by the drawing method. Raman mapping revealed that offline drawn filaments have a higher crystallinity in the core than in the surface region, whereas the opposite is the case for online drawn filaments. The molecular alignment was the highest in the core for all filaments. Microbeam SAXS tomography revealed that the long-spacing between crystals, in the direction of the fiber axis, increases towards the fiber surface. Fibers that have been drawn to a larger extent, resulting in improved tensile strength, have been found to have a larger long-spacing.

High resolution large eddy simulations (LES) are performed to study the interaction of a stationary shock with fully developed turbulent flow. Turbulent statistics downstream of the interaction are provided for a range of weakly compressible upstream turbulent Mach numbers $M_{t}=0.03{-}0.18$, shock Mach numbers $M_{s}=1.2{-}3.0$ and Taylor-based Reynolds numbers $Re_{\unicode[STIX]{x1D706}}=20{-}2500$. The LES displays minimal Reynolds number effects once an inertial range has developed for $Re_{\unicode[STIX]{x1D706}}>100$. The inertial range scales of the turbulence are shown to quickly return to isotropy, and downstream of sufficiently strong shocks this process generates a net transfer of energy from transverse into streamwise velocity fluctuations. The streamwise shock displacements are shown to approximately follow a $k^{-11/3}$ decay with wavenumber as predicted by linear analysis. In conjunction with other statistics this suggests that the instantaneous interaction of the shock with the upstream turbulence proceeds in an approximately linear manner, but nonlinear effects immediately downstream of the shock significantly modify the flow even at the lowest considered turbulent Mach numbers.

In offshore enhanced oil recovery (EOR) applications polymer residence time within the reservoir could be many years. Long term stability (preservation of solution viscosity) within the anaerobic reservoir is a fundamental property of the polymer chemical and consequently highly important for choosing a proper product. For high temperature and/or high salinity reservoirs co-polymers of acrylamide (AM) and acrylamide tertiary butyl sulfonic acid (ATBS) have become common in the industry. The present work aimed at developing generic stability diagrams for such polymers dissolved in seawater (SW). Herein a two-step approach was attempted where stability versus ATBS content was measured at elevated temperature. Thereafter these data were extrapolated to lower temperature. To arrive at a sound extrapolation knowledge of hydrolysis kinetics for the two species, AM and ATBS, was needed. Aqueous solutions of AM-ATBS and AA-ATBS co-polymers were therefore stored at elevated temperature (82–140 °C) and progressive changes in microstructure followed by use of 13C NMR spectroscopy. A steady increase in polymer stability with ATBS content was observed up to around 70 mol%. From 70 to 80 mol% the robustness sharply improved. A striking observation was that stability loss, defined as For the brines tested herein hydrolysis rate was virtually uninfluenced by hardness/salinity, while viscosity was largely impacted. Hence it was concluded that different viscosity loss in various brines stems from carboxylate complexation equilibria and not altered hydrolysis rates. Temperature extrapolation was found to fit a simple Arrhenius approach and it has been suggested that the function should be sound up to around 70 mol% ATBS. With this methodology, the current dataset enabled the construction of a stability diagram for ATBS polymers (0–70 mol% ATBS) dissolved in seawater.

Models for averaged shock corrugation effects and the impact of turbulent entropy or acoustic modes on the energy equation are presented, for application in Reynolds-Averaged Navier Stokes(RANS) simulations of shock-turbulence interactions. Unlike previous work that has focused the modification of turbulent statistics by the shock, the proposed models are introduced to capture the effects of the turbulence on the profiles of primitive variables - mean density, velocity, and pressure. By producing accurate profiles for the primitive variables, it is shown that the proposed models improve numerical convergence behaviour with mesh refinement about a shock, and introduce the physical effects of shock asphericity in a converging shock geometry. These effects are achieved by local closures to turbulent statistics in the averaged Navier-Stokes equations, and can be applied in conjunction with existing Reynolds stress closures that have been constructed for broader applications beyond shock-turbulence int...

The rapid change in scales over a shock has the potential to introduce unique difficulties in Large Eddy Simulations (LES) of compressible shock-turbulence flows if the governing model does not sufficiently capture the spectral distribution of energy in the upstream turbulence. A method for the regularization of LES of shock-turbulence interactions is presented which is constructed to enforce that the energy content in the highest resolved wavenumbers decays as k^(−5/3), and is computed locally in physical-space at low computational cost. The application of the regularization to an existing subgrid scale model is shown to remove high wavenumber errors while maintaining agreement with Direct Numerical Simulations (DNS) of forced and decaying isotropic turbulence. Linear interaction analysis is implemented to model the interaction of a shock with isotropic turbulence from LES. Comparisons to analytical models suggest that the regularization significantly improves the ability of the LES to predict amplifications in subgrid terms over the modeled shockwave. LES and DNS of decaying, modeled post shock turbulence are also considered, and inclusion of the regularization in shock-turbulence LES is shown to improve agreement with lower Reynolds number DNS.

This data in brief article summarizes structural data obtained from monocomponent melt-spun and offline drawn poly(ethylene terephthalate) (PET) monofilaments, as well as from melt-spun bicomponent core-sheath PET-polyamide 6 (PA6) filaments. The diameters of the single filaments range from 27 µm to 79 µm. Presented analysis techniques and results thereof are (i) Raman mapping of filament cross-sections: 2D maps of peak positions, widths, peak area ratios; (ii) attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR): ATR-FTIR spectra and extraction of surface crystallinity; (iii) wide-angle x-ray diffraction (WAXD): WAXD patterns and extraction of average crystallinity; (iv) small-angle x-ray scattering (SAXS): SAXS patterns and determined crystallite sizes and long-spacings; (v) differential scanning calorimetry (DSC): thermograms and extracted average crystallinity as well as thermal properties; (vi) atomic force microscopy (AFM): AFM image of the surface of an embedded fiber cross-section. For more information, see the publication by E. Perret et al. 'High-resolution 2D Raman mapping of mono- and bicomponent filament cross-sections' [1] .

A high-resolution Raman mapping method has been developed in order to obtain 2D information about structural anisotropies (crystallinity, molecular alignment) in thin filament cross-sections (diameters between 27 μm and 79 μm). Cross-sections of melt-spun, hot-drawn poly (ethylene terephthalate) (PET) filaments and bicomponent core-sheath PET-polyamide 6 (PA6) filaments have been scanned through a laser beam (spatial resolution

Numerical methods for the prediction of the hydraulic forcing from rotor stator interaction (RSI) in hydraulic turbines as well as the corresponding methods to calculate mechanical dynamic stresses are mature and well-established in the industry. The geometric factors influencing RSI are generally known, but little information is available on the quantification of these factors with respect to RSI forcing. We present relative quantifications of four geometric factors on RSI forcing expressed as dynamic blade torque. The factors are the blade leading edge lean, the radial distance between guide vane trailing and runner leading edges, the phase between adjacent runner channels as a function of number of guide vanes and blades, and finally the number of guide vanes independently of their effect on the phase. RSI pressure pulsations on the stator in the vane-less space between guide vanes and runner show a different tendency with the variation of the blade number compared to the dynamic blade torque. This indicates that dynamic pressure measurements in the vane-less space are not a good indicator for dynamic forcing on the runner blades.

A zero-dimensional model for the development of turbulent mixing layers driven by Rayleigh–Taylor (RT) or Richtmyer–Meshkov (RM) instabilities is presented, for application in Reynolds-Averaged Navier–Stokes (RANS) simulations. The model approximates the behavior of the turbulent mixing layer at a passively advected tracer particle that sits on the material interface of interest in the simulation, and is used to provide initial conditions for the RANS model once the mixing layer width has developed to a size that may be resolved on the computational mesh. The model relies on approximations to the Besnard–Harlow–Rauenzahn (BHR) RANS closure equations and is thus consistent the turbulent development of the mixing layer, unlike previous models of this type which have focused on the early-time laminar development of RT or RM instabilities. These instabilities will often grow through an initially laminar state before developing into turbulence, and criteria for switching from an existing laminar model to the proposed turbulent model are considered. The proposed model reproduces the mixing layer development of RT and RM instabilities seen in mixed width resolving BHR RANS simulations to a reasonable degree of accuracy, and relaxes the need for the RANS simulation to resolve the mixed width as soon as the mixing layer becomes turbulent, which may be impractical in cases where the mixing layer grows through a wide range of scales.

Summary Polymer flooding is a widely used chemical technique used to enhance or speed up oil recovery from brown or green fields. Polyacrylamides used in chemical enhanced oil recovery processes can be supplied either in powder or inverse emulsion forms. The latter has several benefits for offshore deployment including smaller equipment footprint for dissolution and easier transportation to the site compared to the products in solid form. However, the emulsion is a multi-component system that requires much more attention during the formulation and the implementation than the polymer in powder form; the surfactant package must be adapted to the brine used for inversion (temperature and salinity) in order to allow a perfect release of the macromolecules and a good dispersion of the oil droplets to avoid injectivity issues. Moreover, depending on the field conditions and the dosages that are used, the interactions between the components of the emulsion and the crude has to be studied. This paper reviews the basics of emulsion formulation and design along with the best practices for evaluation in the laboratory. Basic inversion procedures for rheological evaluations, filtration tests and oil droplet size analysis are described. An attempt is made to list relevant tests that can quickly allow to discard bad formulations. A quick review is presented on the propagation of emulsions in porous media along with the possible interactions between the components of the emulsion and the reservoir. This is illustrated with several core floods performed using Bentheimer cores where pressure profiles, resistance factors and residual resistance factors as well as mitigation techniques are carefully studied in various injection conditions (low and high temperature, with or without crude oil) and compiled with other laboratory tests such as droplet size measurement to isolate the contribution of each component. The discussion is concluded with engineering and logistic aspects to discuss the proper implementation of such product in the field.

To investigate the antimicrobial efficacy of different chemical agents used for denture cleaning.Biofilm samples collected from 10 removable dentures were subjected to 10 disinfection protocols: distilled water for 30 min (negative control); 1% sodium hypochlorite for 10 min (positive control); diluted sodium hypochlorite for 10 min; vinegar for 20 min; 0.2% peracetic acid for 5 min; alkaline peroxide solution for 5 min; alkaline peroxide solution for 30 min; 0.12% chlorhexidine digluconate for 10 min; 0.05% sodium salicylate solution for 10 min; and enzymatic detergent for 2 min. Each of the samples was plated on petri dishes with Mueller-Hinton agar. The numbers of microbial colonies after 48 h at 37°C were compared using the Kruskal-Wallis and Dunn's tests (α = 0.05).Diluted sodium hypochlorite, vinegar, and chlorhexidine digluconate inhibited bacterial growth, with an effect similar to that of 1% sodium hypochlorite. The 0.2% peracetic acid and 0.05% sodium salicylate solutions were ineffective against bacterial growth, while enzymatic detergent and alkaline peroxide achieved an intermediate effect.Diluted sodium hypochlorite, vinegar, and chlorhexidine digluconate can be considered adequate products for cleaning dentures due to their potential for inhibiting bacterial growth, similar to 1% sodium hypochlorite. However, the effect of these chemical agents on acrylic resin (polymethylmethacrylate) denture base materials needs to be examined to provide complete information about their clinical indication.

A major source of measurements error are those due to external interferences. The control of such errors is of great importance, and often problematic. Such is the case of measuring the flow induced shear stress gradients in a capillary tube and its effect on the response of deposited biological cells. Described is a novel approach of controlling unavoidable interferences. This is based on a 2 phase strategy, where each measured value is extracted separately. Presented are the theoretical conditions enabling such an approach. These were found to be applicable to the task at hand via a specific 2 phase measurement system. While the main objective of this paper concerns basic aspects, some description of the specific capillary system, involving flow and cellular deposits reaction are briefly included.

The value of CT in the preoperative management of tumors of the sacrum is demonstrated. Essential informations for treatment planning are: involved sacral segment, infiltration of sacral foramina and nerve roots, involvement of the sacroiliac joints, ingression of the lumbar spine, infiltration of the pelvic organs and vessels, sciatic nerve and the dorsal soft tissues. In order to prove the competence of the CT in answering these questions we evaluated the CT-examinations of 30 pat. with 14 primary tumors, 9 metastatic tumors and 7 tumors involving secondary the sacrum. The CT findings were correlated with clinical symptoms and surgical reports in 11 pat., with clinical symptoms alone in 19 pat. There was good correlation in the criterias: location and number of involved segments (8/11, 17/19), infiltr. of SI-joints (11/11), infiltr. of lumbar spine (9/11, 18/19), and infiltr. of pelvic organs (10/11), worse correlation in the criterias: nerve root-involvement (2/11, 3/19), and sciatic nerve-infiltr. (7/11, 15/19). Our conclusions are that CT gives helpful preoperative informations deciding about extent of surgical procedure, and surgical approach. The major problem, however, consist in diagnosis of nerve root and sciatic nerve involvement, therefore in poor prediction of postoperative conservation of neural functions. The knowledge of CT-anatomy of sacrum- and important condition for correct segment-location of the tumor is refreshed by outlines of characteristic segmental CT-sections of the sacrum.

43 cases of tumor resection followed by ventral stabilisation are reported in 42 patients with metastases in the spine. Indications for surgery were beginning or incomplete transversal lesion of the spinal cord, bedrest for at least 3 weeks, unsusceible pain caused by instability, or unsuccessful conservative and radiotherapeutic treatment. 46.5% of the cases can be rated as good considering the time of survival and life quality, 18.5% can be judged as a partial success. 7 patients hat to be reoperated in the same level, most of them because of local recurrence. Complications occurred in 40% of the cases. These operations should be performed by a "term of specialists". Postoperative treatment with isotope-, hormone- or radiotherapy is decisive to obtain good results.

Among a total of 680 patients with advanced malignant melanoma, the interval between removal of the primary tumour and first manifestation of tumour progression was more than five years in 47 (6.9%: 28 women and 19 men, mean age 45 [range 27-70] years), more than 10 years in ten of them. In only eight was the thickness of the primary tumour more than 3 mm. A total of 29 patients died after the tumour progression. Survival time ranged from 1 to 120 months, mean 18 +/- 23 months. There was no correlation between manifestation-free interval and survival time after the first progression had occurred. It is concluded from these findings that patients with malignant melanoma should be followed up for at least ten years.

The diagnostic value of immunocytochemical tests was analysed for 19 cases of pulmonary histiocytosis X (PHX) and eight of other types of fibrosing pulmonary disease (sarcoidosis, 3; exogenous allergic alveolitis, 3; chronic pneumonia, 1; fibrosing alveolitis, 1). The cellular, proliferative-fibroblastic and fibrocystic stages in the course of pulmonary changes were differentiated. PHX cells reacted with anti-S 100 protein in all stages. In three cases for which unfixed tissue was available, all PHX cells reacted with antibody Leu-6, and 35% of these cells also reacted with the proliferation marker Ki-67. The few S-100 positive cells from the eight controls were limited to peribronchial tissue. Thus the antibodies Leu-6 and S-100 are useful aids in the diagnosis of PHX.

In 13 patients, mean age 57 (31-78) years, with malignant melanoma of the vulva, 7 of the tumors occurred on the Labia majora, 4 on the Labia minora and 2 on the clitoris. 8 cases involved nodular malignant melanomas, 2 cases each involved a superficial-spreading form and an acrolentiginous form, and one case involved a non-classifiable malignant melanoma. According to histological criteria 10 of 13 tumors showed a high risk of metastasising. At the time of diagnosis one of the patients was in stage II and one in stage III of the disease. Of the 13 patients, 6 died, as a result of the tumor, 5 within the first 2 years. The mean survival time was 15 (6-28) months. In three other cases the disease has reached an advanced stage: stage Ib, II or III. Up to now only 4 patients have remained symptom free, the symptom free interval averaging 62 (33-84) months. This investigation confirms the special characteristics of malignant melanomas of the vulva, which are the predominance of tumors having a bad prognosis and the rapidly progressing course of the disease.

A malignant melanoma was diagnosed and treated during pregnancy in twelve patients average age 29 (19-38) years. Eleven patients were in stage I and one in stage II. One patient presented with 2 primary malignant melanomas. There was no essential difference in localisation or melanoma type in comparison with non-pregnant melanoma patients. From histological criteria (tumor thickness and prognostic index) eight patients in stage I had an intermediate and three a high risk of metastases. When compared with non-pregnant melanoma patients the pregnant patients presented with relatively more melanomas having intermediate and high metastases risk. No prediction as to the course of the disease can be made because of the small number of patients. Published data show, however, that in a pregnant subgroup pregnancy has a negative influence on the course of malignant melanoma.

Using a collective of 54 patients with 76 operated metastases of long bones in carcinoma of the breast and kidney the frequency of local recurrence after intralesional and extralesional (marginal, wide, radical) resection was investigated. 57 operations were done intralesional, 19 extralesional. Local recurrence was seen in 50.8% in the intralesional group on the other hand in only 15% in the extralesional group (p 0.007). Relief of pain was similar in both groups. The postoperative range of motion had worse results after extralesional resection and endoprosthetic replacement. There was no difference between both groups in the manifestation of further metastases.

In a study of 21 patients with osteogenic sarcoma of the apendicular skeleton proven by biopsy, the diagnostic value of computed tomography (CT) for the assessment of intramedullary tumor growth, epiphyseal and joint involvement was determined. CT findings were correlated with histopathologic findings. 10 of the 21 tumors were located far from the epiphysis, in 11 cases the epiphysis was infiltrated. Tumorous involvement of the articular cartilage occurred in 3 patients, in one case the tumor extended beyond the joint. In 85% of the cases the CT report concerning tumor location in regard to the epiphysis was verified histologically. In 3 cases CT overestimated tumor extension.

Agricultural landscapes are changing their appearance with the increasing use of man-made plastic materials in covered agriculture (plasticulture) all around the world. As these affect the landscape visually, increase pollution and decrease local biodiversity, better monitoring and planning of their uses and areas are needed. Using a field spectrometer we studied the spectral properties of a sample of polyethylene sheets and various nets used in Israel. We detected three major absorption features around 1218 nm, 1732 nm and 2313 nm. These were not affected by settling dust, whitewashing or by the underlying surface, but were not apparent in black coloured polyethylene sheets or nets. A hyperspectral AISA-ES image with a spatial resolution of 1 m achieved a detection accuracy of above 90% for bright sheets and nets but of only 70% for the black nets. The best spectral feature for plastic mapping was found to be that around 1732 nm as it does not coincide with spectral features of other minerals, soils, vegetation or atmospheric attenuation. As most of the greenhouses patches in Israel are smaller than 3200 m2, the optimal spatial resolution of a sensor for mapping them should be equal or better than 8-16 m. As a result of their low spectral and spatial resolution, Landsat images proved inadequate for mapping greenhouses, and strengthen the need of hyperspectral technology for that end.

While polymer flooding has proven to be an effective technique to improve oil recovery from mature reservoirs, the new objective pursued by the main stakeholders consists now in optimizing the overall costs and decrease the risks associated to the implementation of chemical enhanced oil recovery methods. This is particularly true for reservoir conditions with high temperatures (above 85°C) using injection brine with high hardness. In such conditions, using specific robust polymers is necessary to ensure stability over months during propagation in reservoirs. These polymers containing Acrylamido-Tert-Butyl-Sulfonate (ATBS) and N- Vinyl Pyrrolidone (NVP) are more expensive than regular HPAM and have to be overdosed to reach target viscosities since their molecular weights are low. In extreme cases, the project can be aborted for economic reasons. However, many fields, especially in South America, have access to very soft injection brines with a total dissolved salt lower than 3000 ppm in many cases. Using such brine is a tremendous advantage for polymer flooding since less robust polymers can be selected and target viscosity can be achieved with low dosages. This paper describes the selection and evaluation of polymers dedicated to high temperature reservoir conditions (from 85°C to 140°C) using very low salinity brine in comparison with harder brine. A series of rheological, shear and thermal stability tests have been performed to select the most appropriate polymer for each case. The impact of the chemical composition and the microstructure shows that the incorporation of NVP is not necessarily required to ensure stability over 6 months above 100°C in soft brines. Results show as well that ATBS improves shear and thermal stability in both soft and hard brine conditions. Besides, the incorporation of thermo-responsive moieties in the polymer improves viscosity properties resulting in a lower dosage even at high temperature to reach target viscosity. The objective of the study is also to demonstrate the possibility to develop innovative and cost-effective polymers for each reservoir condition. It encompasses an early and particularly close cooperation between the polymer manufacturer and the company willing to improve oil recovery from its reservoirs.

While polymer flooding has proven to be an effective technique to improve oil recovery from mature reservoirs, the new objective pursued by the main stakeholders consists now in optimizing the overall costs and decrease the risks associated to the implementation of chemical enhanced oil recovery methods.Several options do exist to tackle these challenges. Developing more costeffective polymers is one of these. Traditional partially hydrolyzed polyacrylamides (HPAM) are sensitive to brine hardness and temperature; increasing both lead to a drop in viscosity which could be detrimental to the success of the project. As a result, it is generally necessary to increase the dosage of the HPAM to reach the targeted viscosity and balance for the viscosity drop induced by polymer collapse, but always at the expense of the economics of the project. In extreme cases, the project can be aborted for economic reasons. This paper describes a new class of polymers, called “stimuli-responsive”, which has been designed to overcome the aforementioned challenges.This new family of polyacrylamide-based polymers has structurally modified to counterbalance the negative effect of salinity and temperature encountered during the transit through the reservoir. The placement, number and quantity of stimuliresponsive grafts can be finetuned to each reservoir condition to develop its full potential in the subterranean formation. This variable comes on top of other possible adjustments made to the polymer backbone including molecular weight, hydrolysis and incorporation of thermostable groups such as ATBS (acrylamide tertio butyl sulfonic acid) and/or NVP (Nvinyl pyrrolidone).A series of rheological tests has been performed to demonstrate several features of the solutions prepared from these polymers, including salinity resistance, effect of temperature and longterm stability tests. Moreover, injectivity and retention tests have been performed to evaluate the behavior of these polymers in porous medium. A reduction in the polymer dosage on the injection side and the stimuli responsive behavior of the polymer also open new opportunities to minimize the impact of the presence of said polymer in the coproduced water on surface facilities. Some preliminary experiments have been performed in these directions.The objective of the study is also to demonstrate the possibility to develop innovative and costeffective polymers for each reservoir condition. It encompasses an early and particularly close cooperation between the polymer manufacturer and the company willing to improve oil recovery from its reservoirs.

SUMMARY Seven 3H-TdR-labelled early psoriatic lesions were quantitatively evaluated after serial sectioning and autoradiography. Epidermal thickness was measured planimetrically, whereas labelled cells as well as the number of nuclei present in the dermis were counted. Marked differences in the number of labelled cells as well as in their grain density were observed. These differences correlated with the density of the dermal infiltrate. It is concluded that psoriatic epidermal hyperplasia possibly develops as a response to antecedent and persisting events in the dermis.

Increasing industrial requirements concerning the precision of edge geometry lead to the investigation of burr formation, particularly in finishing operations such as grinding. In the present paper, a fundamental investigation of burr formation in the flat surface grinding of tempered tool steel (90MnCrV8) is presented. Conventional and superabrasive grinding wheels with different grain sizes and materials are used under varying cutting conditions. In addition, a ‘hybrid grinding wheel’, which essentially is the wheel hub of a superabrasive wheel with an aluminium oxide abrasive layer, is used in order to isolate the influence of the abrasive material. The geometry of the generated exit burrs at the workpiece edge is investigated. The geometrical burr parameters are measured using optical microscopy. Furthermore, measured grinding forces and temperatures are correlated with the burr parameters. In addition, the microstructure of the burr material is analysed by metallographic sections. As a result of the experimental investigations, an approach to describing burr formation mechanisms in grinding as well as the influences of grinding wheel and cutting parameters on burr shape and size is obtained.

The lifetime of the Bs0 meson is measured in approximately 3 million hadronic Z decays accumulated using the ALEPH detector at LEP from 1991 to 1994. Seven different Ds− decay modes were reconstructed and combined with an opposite sign lepton as evidence of semileptonic Bs0 decays. Two hundred and eight Ds−l+ candidates satisfy selection criteria designed to ensure precise proper time reconstruction and yield a measured Bs0 lifetime of τ(Bs0) = 1.59−0.15+0.17 (stat) ±0.03 (syst) ps. Using a larger, less constrained sample of events, the product branching ratio is measured to be Br ( b → B s 0 ) · Br(B s 0 → D s − l + νX) = 0.82 ± 0.09 (stat) −0.14+0.13 (syst) %.

Using 1.45 million hadronic Z decays collected by the ALEPH experiment at LEP, the b → τ − ν - τ X branching ratio is measured to be 2.75 ± 0.30 ± 0.37%. In addition an upper limit of 1.8 × 10 −3 at 90% confidence level is placed upon the exclusive branching ratio of B − → τ − ν - τ . These measurements are consistent with SM expectations, and put the constraint tan β M h ± GeV −1 at 90% confidence level on all Type II two Higgs doublet models (such as the MSSM).