The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Management of intra-abdominal infections : recommendations by the WSES 2016 consensus conference

This paper reports on the consensus conference on the management of intra-abdominal infections (IAIs) which was held on July 23, 2016, in Dublin, Ireland, as a part of the annual World Society of Emergency Surgery (WSES) meeting. This document covers all aspects of the management of IAIs. The Grading of Recommendations Assessment, Development and Evaluation recommendation is used, and this document represents the executive summary of the consensus conference findings.Peer reviewe

Surviving Sepsis Campaign: international guidelines for management of severe sepsis and septic shock, 2012

OBJECTIVE: To provide an update to the "Surviving Sepsis Campaign Guidelines for Management of Severe Sepsis and Septic Shock," last published in 2008. DESIGN: A consensus committee of 68 international experts representing 30 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict of interest policy was developed at the onset of the process and enforced throughout. The entire guidelines process was conducted independent of any industry funding. A stand-alone meeting was held for all subgroup heads, co- and vice-chairs, and selected individuals. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development. METHODS: The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence from high (A) to very low (D) and to determine the strength of recommendations as strong (1) or weak (2). The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasized. Recommendations were classified into three groups: (1) those directly targeting severe sepsis; (2) those targeting general care of the critically ill patient and considered high priority in severe sepsis; and (3) pediatric considerations. RESULTS: Key recommendations and suggestions, listed by category, include: early quantitative resuscitation of the septic patient during the first 6 h after recognition (1C); blood cultures before antibiotic therapy (1C); imaging studies performed promptly to confirm a potential source of infection (UG); administration of broad-spectrum antimicrobials therapy within 1 h of the recognition of septic shock (1B) and severe sepsis without septic shock (1C) as the goal of therapy; reassessment of antimicrobial therapy daily for de-escalation, when appropriate (1B); infection source control with attention to the balance of risks and benefits of the chosen method within 12 h of diagnosis (1C); initial fluid resuscitation with crystalloid (1B) and consideration of the addition of albumin in patients who continue to require substantial amounts of crystalloid to maintain adequate mean arterial pressure (2C) and the avoidance of hetastarch formulations (1B); initial fluid challenge in patients with sepsis-induced tissue hypoperfusion and suspicion of hypovolemia to achieve a minimum of 30 mL/kg of crystalloids (more rapid administration and greater amounts of fluid may be needed in some patients (1C); fluid challenge technique continued as long as hemodynamic improvement is based on either dynamic or static variables (UG); norepinephrine as the first-choice vasopressor to maintain mean arterial pressure ≥65 mmHg (1B); epinephrine when an additional agent is needed to maintain adequate blood pressure (2B); vasopressin (0.03 U/min) can be added to norepinephrine to either raise mean arterial pressure to target or to decrease norepinephrine dose but should not be used as the initial vasopressor (UG); dopamine is not recommended except in highly selected circumstances (2C); dobutamine infusion administered or added to vasopressor in the presence of (a) myocardial dysfunction as suggested by elevated cardiac filling pressures and low cardiac output, or (b) ongoing signs of hypoperfusion despite achieving adequate intravascular volume and adequate mean arterial pressure (1C); avoiding use of intravenous hydrocortisone in adult septic shock patients if adequate fluid resuscitation and vasopressor therapy are able to restore hemodynamic stability (2C); hemoglobin target of 7-9 g/dL in the absence of tissue hypoperfusion, ischemic coronary artery disease, or acute hemorrhage (1B); low tidal volume (1A) and limitation of inspiratory plateau pressure (1B) for acute respiratory distress syndrome (ARDS); application of at least a minimal amount of positive end-expiratory pressure (PEEP) in ARDS (1B); higher rather than lower level of PEEP for patients with sepsis-induced moderate or severe ARDS (2C); recruitment maneuvers in sepsis patients with severe refractory hypoxemia due to ARDS (2C); prone positioning in sepsis-induced ARDS patients with a PaO (2)/FiO (2) ratio of ≤100 mm Hg in facilities that have experience with such practices (2C); head-of-bed elevation in mechanically ventilated patients unless contraindicated (1B); a conservative fluid strategy for patients with established ARDS who do not have evidence of tissue hypoperfusion (1C); protocols for weaning and sedation (1A); minimizing use of either intermittent bolus sedation or continuous infusion sedation targeting specific titration endpoints (1B); avoidance of neuromuscular blockers if possible in the septic patient without ARDS (1C); a short course of neuromuscular blocker (no longer than 48 h) for patients with early ARDS and a PaO (2)/FI O (2) 180 mg/dL, targeting an upper blood glucose ≤180 mg/dL (1A); equivalency of continuous veno-venous hemofiltration or intermittent hemodialysis (2B); prophylaxis for deep vein thrombosis (1B); use of stress ulcer prophylaxis to prevent upper gastrointestinal bleeding in patients with bleeding risk factors (1B); oral or enteral (if necessary) feedings, as tolerated, rather than either complete fasting or provision of only intravenous glucose within the first 48 h after a diagnosis of severe sepsis/septic shock (2C); and addressing goals of care, including treatment plans and end-of-life planning (as appropriate) (1B), as early as feasible, but within 72 h of intensive care unit admission (2C). Recommendations specific to pediatric severe sepsis include: therapy with face mask oxygen, high flow nasal cannula oxygen, or nasopharyngeal continuous PEEP in the presence of respiratory distress and hypoxemia (2C), use of physical examination therapeutic endpoints such as capillary refill (2C); for septic shock associated with hypovolemia, the use of crystalloids or albumin to deliver a bolus of 20 mL/kg of crystalloids (or albumin equivalent) over 5-10 min (2C); more common use of inotropes and vasodilators for low cardiac output septic shock associated with elevated systemic vascular resistance (2C); and use of hydrocortisone only in children with suspected or proven "absolute"' adrenal insufficiency (2C). CONCLUSIONS: Strong agreement existed among a large cohort of international experts regarding many level 1 recommendations for the best care of patients with severe sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for this important group of critically ill patients

Outlet Works for Taylorsville Lake, Salt River, Kentucky: Hydraulic Model Investigation

Source: https://erdc-library.erdc.dren.mil/jspui/Model investigation of the outlet works for Taylorsville Lake was concerned with verification and improvement of the hydraulic design of the intake structure, conduit, and stilling basin. The study was conducted on a 1:25-scale model of the outlet works which reproduced a portion of the approach area, the intake structure, the outlet conduit, the hydraulic-jump type stilling basin, and approximately 120 ft of exit channel. The proposed intake structure provided effective regulation of both flood-control and water-quality releases. Flow and pressure conditions were satisfactory for all expected operating schemes. However, certain extreme operational procedures must be avoided to prevent subatmospheric pressures in the throat section of the water-quality system and flow instabilities in the wet well during selective withdrawal and in the conduit during flood-control flow. Performance of the original design stilling basin was unacceptable as unstable hydraulic action in the basin resulted in poor energy dissipation. Eddy formation throughout the lower range of discharges was a difficult problem to overcome because of the relatively low elevation of the outlet portal invert with respect to the tailwater elevation. A humped trajectory with the central section raised higher than the sides (type 8 basin) diverted more flow to the sidewalls and eliminated eddying. The chute blocks and tapered training walls of the type 8 basin provided stable basin action with good energy dissipation. Single or uneven gate operation produced unbalanced flow in the stilling basin; however, the eddies were not as severe as in the original design. Since single gate operation is rarely necessary and should be avoided, the type 8 basin is considered to be acceptable for prototype construction

Marysville Lake Hydrothermal Study. Report 2: 2250-MW Project: Hydraulic and Mathematical Model Investigation

Source: https://erdc-library.erdc.dren.mil/jspui/This study was conducted to determine the effect that the proposedMarysville Lake pump-storage hydropower (2250-mw power plant) project would have on downstream water temperatures. A one-dimensional numerical model was used for simulation and prediction of temperatures within and downstream of Marysville Lake. Two physical hydraulic models were used for study and description of the hydrodynamic response of the project. Information from the physical models was necessary to determine coefficients used by algorithms within the mathematical model. The mathematical model allowed simulation of the heat exchange characteristics so the thermal regimes within and downstream of the lake could be determined for various hydrologic and meteorologic conditions and various pumped-storage hydropower operations. Results of the study indicate that the temperatures should be within the objective band desired downstream during years with average or wetter than average hydrologic conditions. The study indicated that with the ultimate 2250-mw power plant fall temperature objectives would be exceeded by a maximum of 3°C for a 45-day period during much drier than average years. With the initial installed capacity of 1350 mw, fall temperature objectives could be met under all conditions studied

Investigation of Release Temperatures for Kinzua Dam, Allegheny River, Pennsylvania: Hydrid Model Investigation

Source: https://erdc-library.erdc.dren.mil/jspui/Kinzua Dam, which impounds the Allegheny Reservoir, is a multipurpose project that includes pumped-storage hydropower and flood control. Prior to the construction of Kinzua Dam, the Allegheny River in the vicinity of Kinzua Dam was considered primarily a warmwater stream and supported an important smallmouth bass sport fishery. Since the construction of the dam and power station, stream temperatures below the dam have been colder than expected. To address this problem, a hybrid modeling study was initiated to determine the causes of colder-than-expected releases and to identify and evaluate measures that could be taken to increase the release temperatures. The existing data base alone was insufficient to determine the causes of colder-than-expected releases. Additional temperature data were collected, and the enlarged data base was used to better understand the physical processes to be simulated in a pumped-storage reservoir thermal simulation numerical model. A physical model, scale 1:100, of the inlet-outlet structure and the surrounding Allegheny Reservoir near-field topography was used during the study to determine the selective withdrawal and pumped-storage mixing characteristics. Mathematical thermal model simulations were used to determine the major factors contributing to the release characteristics. Subsequently, the model was used to evaluate various structural and operational modifications to increase release temperatures. The study determined that the pumped-storage operations have not been the cause of the colder-than-desired releases. Pumped-storage actually causes the hypolimnion to warm faster without significant cooling of the epilimnion. Structural modification of the sluices was determined to be the most effective and practical means of releasing warmer water

Effects of Flood Flows on Water Quality of Tioga-Hammond Lakes : Hydraulic Model Investigation

Source: https://erdc-library.erdc.dren.mil/jspui/The physical model investigation was conducted to estimate the dilution and dispersion of acidic and alkaline substances within Tioga-Hammond Lakes as a result of flood flows and to determine the concentration of these substances in the outflow during drawdown. The model, constructed to a distorted length scale ratio of 1:100 vertically and 1:2000 horizontally, consisted of Tioga and Hammond Lakes, the connecting channel of the dual reservoir system, Hammond outlet works, and the flood control intakes of Tioga outlet works. The model simulated density variations and stratifications expected to exist in the prototype due to temperature differences and reproduced the unsteady inflow and outflow hydrographs for various size floods. Concentrations of fluorescent dyes simulated the acidic and alkaline substances; water samples were collected and analyzed to determine the dilution and dispersion of the dyes throughout the lakes and in the outflow from the lakes. The expected concentrations of acidic and alkaline substances existing in the two lakes after flood inflows and drawdown and in the outflow during drawdown are presented for three flood conditions. The results provide information for estimating water quality for similar flood conditions within and downstream of the project and guidance for limiting adverse quality during drawdown

U.S. Waterways Experiment Station Reports

Partial abstract: "This study was conducted to determine the effect that the proposed Marysville Lake pump-storage hydropower (2250-mw power plant) project would have on downstream water temperatures. A one-dimensional numerical model was used for simulation and prediction of temperatures within and downstream of Marysville Lake. Two physical hydraulic models were used for study and description of the hydrodynamic response of the project. Information from the physical models was necessary to determine coefficients used by algorithms within the mathematical model.

Center Sluice Investigation, Libby Dam, Kootenai River, Montana: Hydraulic Model Investigation

Source: https://erdc-library.erdc.dren.mil/jspui/The model study of the center sluice, Libby Dam, was conducted to determine the causes of and to develop means for preventing the cavitation damage experienced in the sluices. The study was conducted in a 1:20- scale model of the center sluice which reproduced the "as-built" geometry of the bell-mouthed intake, emergency gate slot, regulating gate and gate well, and parabolic trajectory of the sluiceway. The model helped to define undesirable hydraulic conditions that have caused cavitation damage in the prototype structure. Through the use of the model, an aeration device was developed to ventilate the jet and prevent cavitation damage. The recommended aerator (type 7) provided a high degree of aeration without adversely altering flow conditions in the sluice. A certain roof modification was suggested to prevent unstable flow and cavitation damage in the sluice intake