Maximum Bed Research Articles

Performance and sensitivity analysis of the Morpho2DH model in extreme events in southern Brazil

Debris flows are a mixture of water and sediment with a continuous fluid behavior driven mainly by gravity. Computational modeling can be used to predict areas susceptible to these phenomena. When using computational modeling, sensitivity analysis is a crucial step to evaluate and interpret the model results. Thus, the objective of this study was to evaluate the performance of the Morpho2DH debris flow model, perform a sensitivity analysis of its input parameters, recommend application criteria, and increase the use of such a model in South America and Brazil. The model was applied in two representative areas with occurrences of debris flows in southern Brazil. The methodology consisted of two steps: (i) model calibration; (ii) one-at-a-time (OAT) sensitivity analysis (SA) for selected input parameters. The sensitivities of input parameters were evaluated for total area affected, distance traveled, mean velocity, and deposited volume. The results of the SA demonstrate that the most sensitive parameters were maximum bed erosion depth, resistance coefficient, minimum flow depth, and mean particle diameter. Meanwhile, static bed sediment concentration, vegetation, and internal friction angle showed moderate sensitivity. Parameters such as liquid density, sediment concentration, and sediment density showed the lowest sensitivities. Finally, it is recommended to use the model for situations where input volume and terrain data (mainly the erosion thicknesses or soil depth) are well-defined. Additionally, the computational cost of this model should be considered, concerning the magnitude of the event to be simulated.

A New Processing Method for Laser Sintering Polymer Powders at Low Bed Temperatures.

Most current laser sintering (LS) machines for polymer powders operate with a maximum bed temperature of 200 °C, limiting the use of higher melting polymers like polyethylene terephthalate (PET), which melts at ~250 °C. Using bed temperatures of ≤200 °C leads to severe part-distortion due to curl and warpage during the sintering process. The paper presents a processing method for LS at low bed temperatures, using an in situ printed anchor film to conquer curl and warpage. With the use of the anchor film, PET parts were successfully printed without machine stoppage at bed temperatures as low as 150 °C, which is about 80 °C lower than the bed temperature for a regular process for PET without the anchor film. The anchor film acts as a frictional restraint, effectively preventing the curling and warping during printing that typically result from crystallization-induced shrinkage at low bed temperatures. Whereas previous studies have employed 13 mm thick anchoring sheets bolted to the machine to prevent curl and warpage at low bed temperatures, our method uses a flexible in situ printed ~70 μm thick film to which the built part naturally adheres. The in situ printed film is easily detachable from the part after the build. The standard LS material, polyamide 12 (PA12), was also printed with lowered bed temperaturewhere the benefit would be reduced thermal degradation of the powder and decreased energy consumption during the sintering process.

Biphenyl derived hyper-crosslinked polymer as a metal-free adsorbent for the removal of pharmaceuticals from water

The global concern of emergent aquatic pollutants, especially pharmaceutical contaminants, emphasizes the necessity for metal-free adsorbents to tackle water contamination issues. In this direction, a biphenyl-derived hyper-crosslinked polymer (poly-biph) was utilized as an adsorbent for the removal of ciprofloxacin (CPX) and doxycycline (DOX) from water. Micro-mesoporous hyper-crosslinked polymeric adsorbent (poly-biph) was synthesized by using biphenyl as precursor and formaldehyde dimethyl acetal (FDA) as crosslinker via microwave assisted method. It exhibits specific surface area (SABET) and pore volume of 1088 m2/g and 1.3 cm3/g, respectively. The spectral analysis confirmed the successful crosslinking of biphenyl with the linker FDA. The sorption efficiency of metal-free poly-biph for CPX and DOX was evaluated via batch and continuous flow modes under various operational parameters. poly-biph exhibited swift removal efficiency (>80 %) for CPX and DOX within a min. The batch mode sorption modeling revealed a chemisorption process and remarkable maximum sorption capacity of 470.8 and 425.1 mg/g for CPX and DOX, respectively. The continuous-flow studies of poly-biph revealed the better applicability of the Clark kinetic model with a maximum bed capacity of 313.5 and 372.4 mg/g for CPX and DOX, respectively. Synergistic mechanisms, including π-π interaction, electrostatic interaction, and pore-filling effect, were found to be the main driving forces for the sorptive removal of CPX and DOX onto poly-biph. The findings indicated that poly-biph possesses the ability to effectively eliminate DOX and CPX from the aquatic environment.

Experimental performance analysis of methanol adsorption in granular activated carbon packed bed through design of a double pipe heat exchanger with longitudinal fins

Activated carbon (AC) is essential for its exceptional adsorption properties and high surface area in various applications. Adsorption/desorption (A/D) processes with AC can be exothermic or endothermic, necessitating improved heat exchanger (HE) designs due to AC's low thermal conductivity. This study presents an A/D HE design with longitudinal fins in the sorption bed to enhance heat transfer during methanol A/D in AC. Bed heating/cooling uses water flowing through pipes inside the HE. Experimental investigations focus on thermal characteristics and A/D efficiency under diverse conditions, comparing results to a base non-finned HE design. Various experiments measured HE shell temperatures at different water flow rates while varying the sorption bed condition (vacuumed, filled with air, or methanol). The finned HE design showed a 1.8 °C increase in maximum bed surface temperature and a 3-h, 40-min reduction in process time compared to the non-finned HE. Subsequent tests with the finned HE at different water flow rates (5, 10, and 15 l/min) demonstrated superior heat transfer at 15 l/min due to turbulent flow enhancement. Additionally, adsorption ceased at a bed temperature of 54 °C. These findings highlight the efficacy of finned HE for optimizing methanol A/D processes, offering insights into improving heat transfer in AC-based systems.

Design and stabilization of direct autothermal methane steam reformation reactor for producing hydrogen via optimizing oxygen distributed feeding

Direct autothermal methane reforming is an energy-efficient way of hydrogen production. However, significant hot spot is always encountered near the reactor inlet, causing catalyst sinter and even reactor damage. Hence, bed temperature regulation by oxygen distributed feeding was numerically investigated using a one-dimensional heterogeneous model. Simulation results show oxygen feeding along full length of reactor leads to low methane and oxygen conversion despite avoiding hot spot. Elevating feeding temperature solves this problem, but requires extra heat. Shortening feeding length to 1/10 of reactor reduces maximum bed temperature by 100 K; Half oxygen fed into reactor inlet and the other along the length further reduces maximum bed temperature and avoids the transient runaway. Optimization results show that oxygen parabolically and totally fed along the front part of the reactor length shows better performance than that feeding half along reactor length and the other into reactor inlet.

Bank Retreat Mechanisms Driven by Debris Flow Surges: A Parameterized Model Based on the Results of Physical Experiments

AbstractLateral erosion is a critical factor that influences the formation and amplification of debris flows. However, our understanding of the bank retreat process in debris flow channels is limited, which limits the evaluation of debris flow magnitudes and the prediction of their activity trends. Herein, we conduct physical experiments to investigate bank retreat mechanisms using five types of bank soil and multiple debris flow surges. The bank retreat process is categorized into two stages: toe cutting and bank collapse. Toe cutting is mainly caused by hydraulic erosion, bank collapse includes gravity erosion in the form of toppling failure. Notably, the bank retreat process exhibits a significant negative feedback loop. Bank erosion widens the channel bed, subsequently decreasing the flow depth. In turn, this reduction in flow depth mitigates bank erosion. Moreover, we discover a concise pattern in the complex coupling of hydraulic erosion and toppling failure: erosion efficiency is linearly and negatively correlated with the bed widening width. We develop a new parameterized model for describing the bank retreat process and provided empirical values for the model parameters. Furthermore, we observe that the initial erosion efficiency first increases and then decreases with an increase in the fine particle content of the bank soil. Additionally, we report a negative correlation between the maximum bed widening width and the fine particle content in the bank soil that follows a power function relationship.

Understanding the Role of Sharp Edges in the Propagation of Surface Gravity Waves

AbstractUltra‐rough oceanic surfaces, such as oyster reefs, are characterized by densely‐packed, sharp‐edged roughness elements that induce high frictional resistance on the ambient flows. To effectively employ, for example, oyster reefs as a nature‐based solution in coastal protection, a detailed understanding of the frictional wave energy dissipation processes is necessary. This work reports on an experimental study in which six surrogates of very to ultra‐rough oceanic bed surfaces were subjected to regular waves. The influences of different sharpness' of roughness elements (bluntly‐shaped, sharp‐edged, and a combination thereof) and relative spacing between elements compared to the near‐bed horizontal excursion amplitude, λ/ab, on the wave attenuation have been investigated. Turbulence is 2–27 times larger for sharp‐edged surfaces and 1 to 18 times larger for mix surfaces than those of bluntly‐shaped surfaces. Maximum bed shear stresses, hydraulic roughness lengths, and wave friction factors are likewise significantly larger for sharp‐edged compared to bluntly‐shaped surfaces. These observations indicate that the sharp edges are crucial for frictional energy dissipation. Comparing the maximum bed shear stresses determined from wave height reductions to those determined from velocity measurements indicates that in addition to turbulent kinetic energy (TKE), periodic form‐induced stresses significantly contribute to the overall bed shear stresses. This study provides new insight into the frictional dissipation processes of oscillating flows encountering ultra‐rough surfaces.

Processes Towards Sedimentation around a Reed Island in a Shallow Lake

There are many studies on the hydromorphological impacts of emergent aquatic vegetation, but many of these focus on gravity-driven flows in riverine or tidal environments. However, an added effect of emergent vegetation in lakes is that it reduces the main external force (wind) significantly and in a spatially coherent way. We performed long Monte Carlo simulations using a 2D hydrodynamic model and a spectral wind wave model to study resuspension dynamics around a 100-m-wide reed island in southern Lake Fertő/Neusiedl. Wave-current interaction, computed in a post-processing step, was found to enhance maximum bed shear stresses only on the leeward side of the reed island, and even there to a small extent. We have found evidence that the present bed topography is close to an equilibrium where simulated combined wave-current shear stresses have a reasonably uniform exceedance probability over the critical shear stress of the bed sediment. We also found that an artificially flattened lakebed around the reed island would start evolving towards the present bed topography and grain size distribution (both of which were surveyed in the field). Despite the limitations of our modelling framework, our results illustrate the importance of how wind climate is translated to an uneven distribution of sediment entrainment around the reed island, explaining tendencies of sediment accumulation and sorting. Our results lead to a better understanding of the complicated processes involving interaction among wind, vegetation, circulation, wind waves, sediment and bathymetry.

Exploring the Consequences of Aggressive Experiences on Psychiatric Nurses: A Real‐Time Assessment Study

Aims: Aggression on psychiatric wards is a complex issue with significant consequences for both patients and healthcare providers. This study aimed to investigate the behavioural and emotional consequences of aggressive experiences on nurses working in psychiatric wards both at work and at home as well as the contribution of nurses’ behaviour to the development of aggression.Methods: This research utilised the experience sampling method (ESM) to collect real‐time data from nurses working in a high intensive care (HIC) unit within a mental health institution in the Netherlands.Results: The findings revealed that most nurses reported good sleep quality, feeling fit for the day and looking forward to starting their day. These reports were not significantly associated with having a workday ahead or the number of patients admitted. There was a negative association with the number of admitted patients being on or over the maximum bed capacity, although not significant.There were no statistically significant associations between the answers to the morning questionnaire and the behaviour and emotions of nurses and patients later that day nor the appearance of aggressive incidents. Experiencing an aggressive incident had no influence on the sleep of the nurse later that day, nor on their social behaviour.Conclusion: This study offers valuable insights into the daily experiences of nurses in psychiatric wards, particularly in relation to aggression. The real‐time data collection by ESM allowed for a nuanced understanding of nurses’ behaviours and emotions. No significant associations were found between nurses’ functioning and aggressive incidents happening on the ward, but this study might have been contextually influenced so that this study mainly highlights the need for further research with larger samples and across multiple wards to draw definitive conclusions.

Tuneable functionalized biochar for simultaneous removal of pharmaceuticals from binary mixture

Eliminating different pharmaceutical contaminants simultaneously from wastewater has become a crucial environmental issue. In this regard, the shift from the conventional methods of removing single pollutant to implementing a system that simultaneously removes multiple contaminants is required. In pursuit of this goal, functionalized biochar (FBC) was prepared from bamboo sawdust to simultaneously remove pharmaceutical pollutants in batch and fixed-bed sorption systems. FBC exhibited a greater removal capacity for acetaminophen (ACM) (192.43 mg/g) compared to ciprofloxacin (CIP) (70.95 mg/g), as predicted by the Langmuir isotherm model. The competitive Langmuir isotherm model, employed for the binary component, predicted a maximum adsorption capacity of 125.31 mg/g for ACM and 65.44 mg/g for CIP. The adsorption capacity ratio (qm binary/qm single < 1) suggests an antagonistic behavior of these pollutants when they co-exist in the water matrix. On the other hand, the single and binary component adsorption of ACM and CIP was best described by pseudo-second-order kinetic model, indicating that the adsorption process was mainly controlled by the chemisorption process. Fixed-bed column study showcased the maximum bed capacity of ACM (172.48 mg/g) and CIP (147.67 mg/g), with the highest respective removal efficiency of 44.23% and 37.86% in the binary component adsorption system. However, the single-component column adsorption system achieved a higher removal efficiency of 65.83% (ACM) and 42.59% (CIP). These results indicate that the simultaneous removal of ACM and CIP depends on the unique molecular properties of ACM/CIP and their interactions with the adsorbent. Hence, the as-synthesized FBC has been proven effective for the simultaneous removal of ACM and CIP from various water matrices.

Numerical Simulation of Fluidization Behavior and Chemical Performance for Hydrochlorination of Silicon Tetrachloride in a Fluidized Bed Reactor

Exploring the fluidization behaviors and chemical performance in silicon tetrachloride (SiCl4) hydrochlorination processes within a fluidized bed reactor (FBR) poses significant challenges. In this study, we developed an Eulerian-granular model (EGM) by integrating the Eulerian–Eulerian two-fluid model with the kinetic theory of granular flow (KTGF). The effect of fluidization velocities on the flow regime, heat transfer, and chemical reaction performance were investigated. The applicability of the simulation method and the validity of the model were confirmed through comprehensive comparisons, including the simulated values of the maximum bed expansion height (Hmax) with theoretical values derived from empirical formulas and the simulated gas temperature profile with Hsu’s experimental data. The results indicate that the present EGM can be feasible to describe the variation of the flow regime within the FBR. An increase in bed voidage over time, coinciding with transitions in the flow regime, can be observed. Particularly noteworthy was the attainment of a more uniform distribution of SiCl4 under the bubbling fluidization state. Furthermore, the FBR possess high heat transfer characteristics, and the reaction gas can reach the set temperature of the bed after entering a small distance (about 10 mm). The presence of circulating bubbles within the FBR enhances the mixing uniformity of the SiCl4 reaction gas and silicon particles, particularly in the central and upper regions of the bed under the bubbling fluidization state. As a result, the predicted highest concentration of SiHCl3 was 13.08% and the conversion rate of SiCl4 was 28.97% under the bubbling fluidization state. Our results can provide a theoretical basis for further understanding of the hydrochlorination process of SiCl4 within the FBR.

Rapid and convenient synthesis of “green” ammonium-modified chitosan composite sponge with the existence of ascorbic acid for highly efficient removal of Congo red (CR)

In this study, a new green composite sponge made of chitosan and modified with ammonium ascorbate (ACS-CIT) was synthesized in just 10 min. Compared with CS-CIT (sponge prepared from acetic acid), ACS-CIT exhibits significantly enhanced adsorption performance for CR, with the saturated adsorption capacities increased from 353.667 to 1261.639 mg·g−1. The adsorption mechanism can be summarized as the generation of more hydrogen bonds, electrostatic attraction, and intra particle diffusion, revealing the addition of ascorbic acid introduced more hydroxyl groups, thereby enhancing the hydrogen bonding force, and the ammonium modification of chitosan improved the electrostatic attraction of the material, resulting in a significant increase in its adsorption capacity. Additionally, the prepared ACS-CIT showed excellent CR removal performance even in the presence of multiple interfering factors coexisting in the simulated wastewater, and the adsorption capacity remained stable after at least five cycles. Furthermore, the maximum bed capacity of ACS-CIT for CR is 1152.829 mg·g−1 under the given conditions of a flow rate of 1 mL·min−1, inlet concentration of 150 mg·L−1, a bed height of 1 cm respectively, and the breakthrough curve followed the Thomas model. The results indicated the eco-friendly and recyclable ACS-CIT is a promising adsorbent for CR dye removal in water.

Development of a Tool to Optimise Tidal Stream Energy Sites

Several prospective tidal energy sites have been identified around the UK, however, little is known about the specific, and often complicated, hydrodynamics in many of these area [1]. Many sites comprise complicated seabed and coastline configurations, which can not only give rise to fast-flowing currents, but also results in highly turbulent and spatially-varying currents. These latter features are undesirable characteristics for devices.&#x0D; Tidal stream energy developers seldom design devices to suit a particular site, rather devices are designed and suitable sites located subsequently. This reduces the number of viable sites as each device has its own design constraints, e.g. minimum water depth, minimum velocity, etc. In order to maximise the exploitability of these sites, where space is generally limited, it would be more beneficial for developers to design devices once site conditions/constraints are better understood.&#x0D; An open-source tool is being developed that determines the physical constraints of a site based primarily on bathymetry and current velocities (measured and/or modelled). This tool aims to optimise a site to help developers understand what conditions need to be met in order to maximise energy generation – it will also identify which areas are unsuitable depending on the device design. The flexibility of the tool ensures two key aspects:&#x0D; &#x0D; For existing devices, the device design parameters can be selected to show which areas are viable that meet these parameters (e.g. maximum bed slope, maximum current velocity, etc.);&#x0D; For devices yet to be designed, different design parameters can be selected to optimise a site to help maximise the energy that can be extracted from a particular site.&#x0D; &#x0D; &#x0D; The tool is being written in Python with a QGIS front end to allow the user to make changes readily and choose which parameters are important. Not only will the tool identify suitable sites based on user-defined parameters, it will also calculate how much power is available (in kW/m2) based on velocity data.&#x0D; Given the data availability and interest from tidal energy developers in Ramsey Sound (Figure 1) and to the west of Ramsey Island in West Wales, UK, this site has been chosen as a case study. This site also experiences significant spatial and temporal variation in flow, caused in part by a narrowing of the Sound, which accelerates flow [2]. Once this tool has been proven it will be expanded to assess the viability of other tidal energy sites, both in the UK and overseas. Sensitivity testing is currently underway to determine how sensitive the tool is to data resolution. For example, do higher resolution bathymetry and velocity datasets provide a marked difference in the areas that are viable. &#x0D; This tool will demonstrate that developers (and other relevant parties in the supply chain) cannot rely on first-order appraisals, which may make energetic tidal straits attractive sites for development since their resource potential depends on flow conditions that are fundamentally local.

Preparation of granulated powders via freeze drying at different levels of slurry solid loading and comparison of their powder bed quality in roller-compaction-assisted binder jetting

Granulation can improve the flowability of nanopowder and the density of resultant parts printed by binder jetting. Forward-rotating roller compaction has the potential for further improving the density. In this study, for the first time, powder recoating tests of different granulated alumina powders were conducted on a commercially available binder jetting printer equipped with a forward-rotating roller compaction system. Freeze drying was used to prepare the granulated powder. Four different granulated powders were prepared from slurries with different levels of solid loading: 2, 5, 10, and 15 vol%, respectively. Powder bed quality, including defects on powder bed surface and maximum powder bed density without defects, was compared among the granulated powders. When the compaction ratio was too high, granulated powders with low solid loading levels of 2 and 5 vol% showed much fewer compaction-induced defects (including surface ridges and edge ridges) on powder bed surface than those with high solid loading levels of 10 and 15 vol%. As the solid loading level increased from 2 to 15 vol%, the maximum powder bed density without defects decreased from 19.5% to 16.0%. This study showed that a granulated powder prepared from a low level of slurry solid loading could reduce the compaction-induced defects on powder bed surface and enhance the powder bed density in roller-compaction-assisted binder jetting.

Numerical Investigation of Bed Shear Stress and Roughness Coefficient Distribution in a Sharp Open Channel Bend

The helical flow leads to the redistribution of the bed shear stress and roughness coefficient in open-channel bends, influencing the transport of sediment and riverbed evolution process. To explore the mechanisms underlying this redistribution, a 3D numerical simulation of a 180° sharp bend was performed by solving the Reynolds-averaged Navier–Stokes (RANS) equations using the Reynolds stress equation model (RSM) as the anisotropic turbulence closure approach. The results indicate that the high bed shear stress zone appeared in the inner bank region from the 50° to 110° sections, and the section maximum bed shear stress gradually shifted outwards, owing to the advective momentum transport by the circulation cells. The quantitative analyses of the terms in depth-averaged Navier-Stokes equations indicate that the contributions of the cross-stream circulation and cross-flow to the downstream bed shear stress were of the same order of magnitude, and the overall contribution rate of the cross-stream circulation was 20%. The contribution rates of the cross-flow, cross-stream circulation, turbulence, and pressure gradient to the transverse bed shear stress were approximately 30%, 7%, 3%, and 60%, respectively, indicating that the pressure gradient term arising from the transverse water surface slope played a dominant role. The Chezy resistance coefficient showed an overall decreasing trend along the bend. Therefore, an effective expression considering the streamwise variation along the centreline and transverse variation was successfully established to predict the uneven distribution of the Chezy resistance coefficient.

Effect of orange waste pretreatment on the fluid dynamics of spouted beds with mechanical agitation

The spouted bed has a vigorous cyclic movement of the solids and high rates of heat and mass transfer, allowing for effective contact between the different phases. However, the spouted bed may exhibit instabilities for inherently cohesive solids due to unwanted agglomeration, preferential channels, particle segregation and high energy consumption. In this context, the present work analyzed the effect of a preliminary treatment of the orange waste, through the addition of lime and mechanical pressing, on the fluid dynamics in two spouted bed configurations of same dimensions, one conventional (CSB) and the other one modified with mechanical agitation (modified mechanically spouted bed, MMSB). The preliminary treatment of the biomass allowed reducing the moisture content by 31.7%, thereby improving the movement of solids in the CSB as when the in natura (raw) biomass was loaded, as the latter underwent agglomeration until it no longer circulated. Persistent instability issues in the CBS were overcome through mechanical stirrers, which made the bed uniform by improving the movement of solids in the annular region. Furthermore, mechanical agitation allowed increasing the maximum static bed height from 21.1 to 27.0 cm, as well decreasing the air flow by up to 91.74%, since the air stream is only that required for bed expansion.

Role of hospital strain in determining outcomes for people hospitalised with COVID-19 in England

BackgroundIn England, reported COVID-19 mortality rates increased during winter 2020/21 relative to earlier summer and autumn months. This study aimed to examine the association between COVID-19-related hospital bed-strain during this...

Ultra-low concentration terbium (Tb) adsorption on garlic peels biosorbent and its application for Nd-Fe-B scraps recovery

Motivated by the strategic value of middle-heavy rare earth elements (MHREEs), we proposed a bio-adsorption method to recover ultra-low concentration terbium (Tb(Ⅲ)) from industrial wastewater that originated from the Nd-Fe-B scraps recovery process. It could be found that Tb(Ⅲ) ions as low as 5.34 ng·mL−1(ppb) could be adsorbed onto Ca(Ⅱ)-modified garlic peels (Ca-GP) within 10 min with the adsorption efficiency of 99.2% at pH 3.5. The adsorption behavior of Tb(Ⅲ) onto Ca-GP conformed the Langmuir isotherm model and pseudo-second-order kinetic model. ATR-FTIR, XPS and density-functional theory (DFT) calculations results showed that Tb(Ⅲ) ions could be ion-exchanged with cations in Ca-GP such as Ca(Ⅱ) and -COOH. In application, column experiment results showed that the maximum bed adsorption capacity for Tb, praseodymium (Pr), neodymium (Nd), dysprosium (Dy), and Total rare earth elements (REEs) ions calculated by the Thomas model was 0.06, 3.50, 9.65, 7.34, and 27.37 μg·g−1, respectively, with the initial concentration of 0.37 ng·mL−1 Tb, 20 ng·mL−1 Pr, 44 ng·mL−1 Nd, 67 ng·mL−1 Dy and 170 ng·mL−1 total REEs ions of actual solutions (below the solubility of rare-earth hydroxide). This manuscript thus provided a novel cost-effective and efficient approach to the enrichment and recovery of MHREEs from ultra-low concentration REEs ions-containing solutions.

Computed tomography-controlled paravertebral sympathectomy in the treatment of obliterating diseases of the arteries of extremities

Surgeries on the paravertebral sympathetic ganglia still keep their meaning. They become surgeries of choice in cases of peripheral arterial damage. Sympathectomy ensures maximum arterial bed dilation, increases blood flow to the ischemic zone, accelerates the angiogenesis. Minimally invasive chemical destruction of the lumbar sympathetic ganglia under the control of a spiral computed tomograph is an alternative to surgical lumbar sympathectomy. It has comparable effectiveness in comparison with open intervention treatment both in the immediate and long-term periods. The study reflects the results of the influence of computed tomographically controlled puncture paravertebral sympathectomy on the symptoms of obliterating diseases of the arteries of lower extremities.

Staff and ward factors associated with aggression development on an acute closed psychiatric ward: an experience sampling method study.

Studying staff and ward factors including interactions between patients and nurses prior and after development of aggression, within a naturalistic closed ward setting. A prospective naturalistic experience sampling method (ESM) study. A high intensive care unit of a mental health institution in The Netherlands where 29 nurses answered beeps generated by an app during approximately 7 consecutive days with questions regarding their subjective feelings, ward atmosphere, location, interaction they had with patients and their colleagues and whether an incident took place. Associations were established between different staff and ward factors and the occurrence of aggressive incidents on the ward. Risk for aggression was associated with the nurse being with a patient (OR=2.26, 95% CI 0.99 to 5.15, p=0.05). No significant association was found between discussing with the patient and setting a limit or physical absence of the nurse on the one hand and aggression on the other. More experienced nurses encountered more aggression (OR=3.5, 95% CI 1.32 to 8.26, p=0.01). Age and gender of the nurse were not associated with aggression development. Exceeding the maximum bed capacity was associated with a greater risk for aggression (OR=5.36, 95% CI 1.69 to 16.99, p=0.004). There was no significant association when analysing a more positive atmosphere on the ward or positive affect of the nurse, but negative affect of the nurses showed a trend for an association with less aggression. Aggression is a problem that should be managed from a multidimensional perspective. The quality of interaction between nurses and patients is crucial. Exceeding the maximum bed capacity is likely associated with more aggression.