60 research outputs found
Contrasted sediment processes and morphological adjustments in three successive cutoff meanders of the Danube Delta
Since the 1980s intensive anthropogenic disturbances have affected the channel of the St. George branch, the southern distributary of the Danube River. The meander cutoff programme since 1984–1988 induced different hydrosedimentary impacts on the local distribution of river flow velocities, discharge, and sediment fluxes between the former meanders and the man-made canals (Ichim and Radoane, 1986; Popa, 1997; Panin, 2003). This paper selects three large cutoff meander reaches of the St. George branch (the Mahmudia, Dunavăţ de Sus, and Dunavăţ de Josmeanders noted here asM1,M2, andM3, respectively) as an example to analyse the human impact in the Danube River delta. The diversion of the flow induces strong modifications by acceleration of the fluxes through the artificial canals combined with dramatically enhanced deposition in the former meander where it was observed in two cases (M1 and M3) with slight modifications in M2. An exceptional flood that occurred in April 2006 offered a good opportunity for scanning different cross sections of the meander systems. Bathymetry, flow velocity, suspended-load concentration, and liquid and solid discharge data were acquired throughout several cross sections of both natural channels and artificial canals of the three cutoffs, using acoustic Doppler current profiler (ADCP) technology, in order to investigate the distribution of the flowand sediment and its impact on the hydrosedimentary processes in each channelized reach and adjacent former meander. Therefore, the results obtained during the 2006 flood were referred to a long-term evolution (1970–2006), analysed by GIS techniques
FUNCTIONAL CHARACTERISTICS OF ACTIVE SUSPENSION SYSTEMS FOR AGRICULTURAL TRACTORS
Suspension systems are generally used to improve the comfort degree and todiminish or totally avoid injuries caused to drivers (and passengers) when the vehicle is moving on a regular road, usually having irregularities. Some other important functions of the suspension system of one vehicle are to provide driving stability, to maintain a permanent contact between vehicle and road surface, to protect the road surface from damages caused by excessive pressure forces of tires. Active suspension systems are in fact modern closed loop control systems that use all the elements of an automated system: electronic regulator, driving electro-actuators, electronic transducers and signal conditioning devices. Active suspension systems can be programmed to work as passive (classic) suspension systems, but the main goal is to achieve better comfort and improved overall handling of one vehicle at same time
Complex reconstruction after extreme Fournier’s gangrene; a case report
In this article we present a severe case of Fournier\u27s gangrene (FG) that affected a 64-year-old male patient, with no other known comorbidities. FG is a type of necrotizing fasciitis of the perineal and genital regions, that affects mostly males in the 5th-7th decades, with mortality rates that reach 70%. The infection usually advances through the superficial fascial layers of the perineum and abdomen and affects the skin. In our case the infection also affected the spermatic fasciae and advanced in the abdominal and pelvic cavities, abdominal muscles, and surrounding soft tissues. Subsequent debridement left the patient with large soft tissue and muscle defects and an open abdominal cavity that needed reconstruction. We designed two pedicled tensor fascia lata flaps with extra fascia for abdominal support. Healing was marked by a pseudomonas aeruginosa infection that led to skin graft sloughing and marginal wound breakdown, which was treated with antibiotics and local wound care. Eventually the wounds healed, and the patient left the hospital 11 weeks after admittance. The outcome of the case was good considering the initial extent of the infection. The cosmetic shortcomings were not shared by the patient and future scar corrections are planned
CONSIDERATIONS REGARDING THE CONDITIONS OF USING TRACTOR-TRAILER COUPLING DEVICES
Coupling devices can be one of the main causes of accidents on public roads dueto the use of inadequate systems (both on tractors and also on trailers or agricultural machinery), this mainly due to the fact that the systems in question were built most of the times without taking into account the national, European and international regulations that are in force. The paper presents a few aspects regarding the coupling (traction) devices, the conditions of use and the tests that are necessary to be performed for approval before being used on public roads
STATE OF THE ART REGARDING CONSERVATIVE TILLAGE TECHNOLOGIES
Following the expansion of soil degradation processes due to conventional agriculture and technological mistakes, over the years, the so-called conservative agricultural technologies have been studied and implemented in practice. These technologies have contributed substantially to the improvement of soil fertility and productivity and, thus, of other environmental resources. The most important component of conservation technological systems, as in the case of conventional ones, is soil tillage – loosening and processing – and the introduction of seed into the soil. Switching from conventional tillage systems to the conservative ones was not easy and generated a lot of questions that needed relevant answers, scientifically based, some of them being obtained through fundamental and applied research carried out under local specific conditions. Conservative systems are based on the less intense loosening of soil, made by different methods, without furrow return and only while maintaining a given amount of crop residues on soil surface, is being considered for this reason as environmental protection strategies. In this paper is presented an analysis of the state of research on the implementation in agriculture of conservative tillage technologies and the technical-economic and environmental impacts of applying these conservative technologies. Also, there are presented the most advanced research on optimal construction of equipment for soil processing in conservation system
Epidemiology, practice of ventilation and outcome for patients at increased risk of postoperative pulmonary complications
BACKGROUND Limited information exists about the epidemiology and outcome of surgical patients at increased risk of postoperative pulmonary complications (PPCs), and how intraoperative ventilation was managed in these patients.
OBJECTIVES To determine the incidence of surgical patients at increased risk of PPCs, and to compare the intraoperative ventilation management and postoperative outcomes with patients at low risk of PPCs.
DESIGN This was a prospective international 1-week observational study using the ‘Assess Respiratory Risk in Surgical Patients in Catalonia risk score’ (ARISCAT score) for PPC for risk stratification.
PATIENTS AND SETTING Adult patients requiring intraoperative ventilation during general anaesthesia for surgery in 146 hospitals across 29 countries.
MAIN OUTCOME MEASURES The primary outcome was the incidence of patients at increased risk of PPCs based on the ARISCAT score. Secondary outcomes included intraoperative ventilatory management and clinical outcomes.
RESULTS A total of 9864 patients fulfilled the inclusion criteria. The incidence of patients at increased risk was 28.4%. The most frequently chosen tidal volume (VT) size was 500 ml, or 7 to 9 ml kg1 predicted body weight, slightly lower in patients at increased risk of PPCs. Levels of positive end-expiratory pressure (PEEP) were slightly higher in patients at increased risk of PPCs, with 14.3% receiving more than 5 cmH2O PEEP compared with 7.6% in patients at low risk of PPCs (P < 0.001). Patients with a predicted preoperative increased risk of PPCs developed PPCs more frequently: 19 versus 7%, relative risk (RR) 3.16 (95% confidence interval 2.76 to 3.61), P < 0.001) and had longer hospital stays. The only ventilatory factor associated with the occurrence of PPCs was the peak pressure.
CONCLUSION The incidence of patients with a predicted increased risk of PPCs is high. A large proportion of patients receive high VT and low PEEP levels. PPCs occur frequently in patients at increased risk, with worse clinical outcome
Empirical investigation to explore potential gains from the amalgamation of Phase Changing Materials (PCMs) and wood shavings
The reduction of gained heat, heat peak shifting and the mitigation of air temperature fluctuations are some desirable properties that are sought after in any thermal insulation system. It cannot be overstated that these factors, in addition to others, govern the performance of such systems thus their effect on indoor ambient conditions. The effect of such systems extends also to Heating, Ventilation and Air-conditioning (HVAC) systems that are set up to operate optimally in certain conditions. Where literature shows that PCMs and natural materials such as wood-shavings can provide efficient passive insulation for buildings, it is evident that such approaches utilise methods that are of a degree of intricacy which requires specialist knowledge and complex techniques, such as micro-encapsulation for instance. With technical and economic aspects in mind, an amalgam of PCM and wood-shavings has been created for the purpose of being utilised as a feasible thermal insulation. The amalgamation was performed in the simplest of methods, through submerging the wood shavings in PCM. An experimental procedure was devised to test the thermal performance of the amalgam and compare this to the performance of the same un-amalgamated materials. Comparative analysis revealed that no significant thermal gains would be expected from such amalgamation. However, significant reduction in the total weight of the insulation system would be achieved that, in this case, shown to be up to 20.94%. Thus, further reducing possible strains on structural elements due to the application of insulation on buildings. This can be especially beneficial in vernacular architectural approaches where considerably large amounts and thicknesses of insulations are used. In addition, cost reduction could be attained as wood shavings are significantly cheaper compared to the cost of PCMs
Epidemiology, practice of ventilation and outcome for patients at increased risk of postoperative pulmonary complications: LAS VEGAS - An observational study in 29 countries
BACKGROUND Limited information exists about the epidemiology and outcome of surgical patients at increased risk of postoperative pulmonary complications (PPCs), and how intraoperative ventilation was managed in these patients. OBJECTIVES To determine the incidence of surgical patients at increased risk of PPCs, and to compare the intraoperative ventilation management and postoperative outcomes with patients at low risk of PPCs. DESIGN This was a prospective international 1-week observational study using the ‘Assess Respiratory Risk in Surgical Patients in Catalonia risk score’ (ARISCAT score) for PPC for risk stratification. PATIENTS AND SETTING Adult patients requiring intraoperative ventilation during general anaesthesia for surgery in 146 hospitals across 29 countries. MAIN OUTCOME MEASURES The primary outcome was the incidence of patients at increased risk of PPCs based on the ARISCAT score. Secondary outcomes included intraoperative ventilatory management and clinical outcomes. RESULTS A total of 9864 patients fulfilled the inclusion criteria. The incidence of patients at increased risk was 28.4%. The most frequently chosen tidal volume (V T) size was 500 ml, or 7 to 9 ml kg−1 predicted body weight, slightly lower in patients at increased risk of PPCs. Levels of positive end-expiratory pressure (PEEP) were slightly higher in patients at increased risk of PPCs, with 14.3% receiving more than 5 cmH2O PEEP compared with 7.6% in patients at low risk of PPCs (P ˂ 0.001). Patients with a predicted preoperative increased risk of PPCs developed PPCs more frequently: 19 versus 7%, relative risk (RR) 3.16 (95% confidence interval 2.76 to 3.61), P ˂ 0.001) and had longer hospital stays. The only ventilatory factor associated with the occurrence of PPCs was the peak pressure. CONCLUSION The incidence of patients with a predicted increased risk of PPCs is high. A large proportion of patients receive high V T and low PEEP levels. PPCs occur frequently in patients at increased risk, with worse clinical outcome.</p
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