Hydrogen energy systems: Technologies, trends, and future prospects.

This review critically examines hydrogen energy systems, highlighting their capacity to transform the global energy framework and mitigate climate change. Hydrogen showcases a high energy density of 120 MJ/kg, providing a robust alternative to fossil fuels. Adoption at scale could decrease global CO2 emissions by up to 830 million tonnes annually. Despite its potential, the expansion of hydrogen technology is curtailed by the inefficiency of current electrolysis methods and high production costs. Presently, electrolysis efficiencies range between 60 % and 80 %, with hydrogen production costs around $5 per kilogram. Strategic advancements are necessary to reduce these costs below $2 per kilogram and push efficiencies above 80 %. Additionally, hydrogen storage poses its own challenges, requiring conditions of up to 700 bar or temperatures below -253 °C. These storage conditions necessitate the development of advanced materials and infrastructure improvements. The findings of this study emphasize the need for comprehensive strategic planning and interdisciplinary efforts to maximize hydrogen's role as a sustainable energy source. Enhancing the economic viability and market integration of hydrogen will depend critically on overcoming these technological and infrastructural challenges, supported by robust regulatory frameworks. This comprehensive approach will ensure that hydrogen energy can significantly contribute to a sustainable and low-carbon future.

Evaluation of small hydropower turbines installed downstream of Nile River branches (Egypt).

The current study proposes a new strategy for using small hydroelectric turbines in downstream river branches with the least amount of construction and the lowest cost by comparing two different methods of installing the turbines, the first by installing the turbines at the river's bottom and the second by installing the turbines on floating boats. The methodology of this article is based on predicting the distribution of velocities through the watercourse using experimental data collected at various points in the river's depth, and then predicting the resulting electrical power for different sizes of turbines, as well as estimating the number of turbines for each row and the number of rows along the river. Therefore, Investigate the proposed systems. The proposed small hydropower system's economic viability and environmental impact are investigated in this article. According to the nature of the waterway, the best diameter of a turbine that can be used is 1.5 m based on water velocities and river depths. The proposed power plant generated 25.8 kW per single turbine row, with an estimated cost of produced power (0.035 USD/kWh) of approximately 20 turbines installed per row. Compared to other renewable energy sources, the proposed hydropower system is cost-effective and environmentally friendly, as generating electricity with the proposed small hydropower plant could reduce annual carbon dioxide emissions by 368 tones of CO2 per single turbine row.

Dataset for transient 3D simulations of turbulent premixed flames of Gas-to-Liquid (GTL) fuel.

A fan-stirred combustion vessel is used to study the premixed turbulent combustion of diesel, Gas to Liquids (GTL) and 50/50 diesel-GTL and to generate these datasets. A numerical simulation approach is implemented for modelling the premixed combustion of the three fuels under different thermodynamics and turbulence initial conditions, using Zimont Turbulent Flame Speed Closure (Zimont TFC) model. Different parameters are obtained from these simulation runs such as turbulent eddy viscosity (µ), turbulent kinetic energy (k), Damkohler number (Da), Reynolds number (ReT) and turbulent flame speed (St). The raw, filtered and pre-processed data are imported from ANSYS Fluent and then listed on filtered tables for the ease of accessibility. These datasets can be then used to perform research in different related areas such as chemical kinetic mechanisms, ignition delay time, flame ignition mechanisms and flame extinction and diffusion. Also, they can be employed to further understand trends, patterns, and anomalies in data. In addition, they can be compared with other numerical models to establish a robust knowledge about the modelling of premixed turbulent combustion. For more information and discussion of the dataset creation, the reader is directed to the full-length article, "Abdellatif M. Sadeq, Samer F. Ahmed, Ahmad K. Sleiti, Transient 3D simulations of turbulent premixed flames of gas-to-liquid (GTL) fuel in a fan-stirred combustion vessel, Fuel, Volume 291, 2021, 120,184, ISSN 0016 2361, https://doi.org/10.1016/j.fuel.2021.120184" [1].

Dynamic hip screw and fibular strut graft for fixation of fresh femoral neck fracture with posterior comminution.

INTRODUCTION: Posterior comminution of the femoral neck fracture is a major cause of delayed and non-union owing to the loss of the buttressing effect against the posterior rotation. When a femoral neck fracture with posterior comminution is anatomically reduced, only the anterior portions of the femoral neck fracture surfaces are brought into contact leaving a posterior defect. The purpose of this study was to evaluate the use of fibular strut grafting and dynamic hip screw (DHS) for fresh femoral neck fractures with posterior comminution in young patient less than 50 years. MATERIALS AND METHODS: Between October 2012 and March 2016, 35 patients aged 20-50 years, 30 men and 5 women underwent fixation using DHS and fibular strut grafts for Garden grades III (25 patients) and IV (10 patients) femoral neck fractures with posterior comminution. All fractures were reduced by closed methods, and no hip was aspirated. Clinical and radiological outcomes were evaluated. RESULTS: All patients were in the age group of 20-50 years (mean 37 years). The mean delay in presentation after injury was 1 day. The mean final follow-up for these 35 patients was 27.2 months. Healing of the femoral neck was attained in 34 cases, with an average time to union of 4.8 months (range 4-8 months). One patient underwent arthroplasty due to failure of fixation. According to the Harris hip score, outcome was good to excellent in 30 patients, fair in 4, and poor in 1. CONCLUSIONS: In our study, only one patient developed non-union and no patients had avascular necrosis of the femoral head. Closed reduction, fibular strut grafts, and DHS fixation is a reliable procedure for femoral neck fractures with posterior comminution in young adults.

The impact of a multifaceted intervention including sepsis electronic alert system and sepsis response team on the outcomes of patients with sepsis and septic shock.

BACKGROUND: Compliance with the clinical practice guidelines of sepsis management has been low. The objective of our study was to describe the results of implementing a multifaceted intervention including an electronic alert (e-alert) with a sepsis response team (SRT) on the outcome of patients with sepsis and septic shock presenting to the emergency department. METHODS: This was a pre-post two-phased implementation study that consisted of a pre-intervention phase (January 01, 2011-September 24, 2012), intervention phase I (multifaceted intervention including e-alert, from September 25, 2012-March 03, 2013) and intervention phase II when SRT was added (March 04, 2013-October 30, 2013) in a 900-bed tertiary-care academic hospital. We recorded baseline characteristics and processes of care in adult patients presenting with sepsis or septic shock. The primary outcome measures were hospital mortality. Secondary outcomes were the need for mechanical ventilation and length of stay in the intensive unit and in the hospital. RESULTS: After implementing the multifaceted intervention including e-alert and SRT, cases were identified with less severe clinical and laboratory abnormalities and the processes of care improved. When adjusted to propensity score, the interventions were associated with reduction in hospital mortality [for intervention phase II compared to pre-intervention: adjusted odds ratio (aOR) 0.71, 95% CI 0.58-0.85, p = 0.003], reduction in the need for mechanical ventilation (aOR 0.45, 95% CI 0.37-0.55, p < 0.0001) and reduction in ICU LOS and hospital LOS for all patients as well as ICU LOS for survivors. CONCLUSIONS: Implementing a multifaceted intervention including sepsis e-alert with SRT was associated with earlier identification of sepsis, increase in compliance with sepsis resuscitation bundle and reduction in the need for mechanical ventilation and reduction in hospital mortality and LOS.

Application of Failure Mode Effect Analysis to Improve the Care of Septic Patients Admitted Through the Emergency Department.

BACKGROUND: Failure mode effect analysis (FMEA) is a proactive multistep tool used to analyze risks, identify failures before they occur, and prioritize preventive measures. METHODS: A multidisciplinary team trained on FMEA methodology analyzed the process of treatment of septic patients and recorded processes under 3 major phases (recognition of severe sepsis, referral, and resuscitation). The team identified potential failure modes in each process; assigned severity, occurrence, and detection scores for each; and calculated the risk priority numbers (RPNs). Finally, higher-priority failure modes (RPN of ≥300) were analyzed to redesign the care process. RESULTS: We identified 27 processes and 48 failure modes with a mean RPN of 270. Twenty-two high-risk failures were identified by RPN of 300 or higher. All identified critical processes were related to phase 1 (recognition of sepsis) and phase 3 (resuscitation). The most critical process seemed to be related to the initial workup and treatment of septic patients, with 4 potential failure modes and a total RPN of 1485. CONCLUSIONS: Patient safety and care reliability issues are a major concern in health care. This study suggests that tools such as FMEA can enable a detailed analysis of the care process of septic patients by outlining potential failure modes and guiding improvement efforts.

The impact of implementing multifaceted interventions on the prevention of ventilator-associated pneumonia.

BACKGROUND: Ventilator-associated pneumonia (VAP) is a frequent hospital acquired infections among intensive care unit patients. The Institute for Healthcare Improvement has suggested a "care bundle" approach for the prevention of VAP. This report describes the effects of implementing this strategy on VAP rates. METHODS: All mechanically ventilated patients admitted to the intensive care unit between 2008 and 2013 were prospectively followed for VAP development according to the National Healthcare Safety Network criteria. In 2011, a 7-element care bundle was implemented, including head-of-bed elevation 30°-45°, daily sedation vacation and assessment for extubation, peptic ulcer disease prophylaxis, deep vein thrombosis prophylaxis, oral care with chlorhexidine, endotracheal intubation with in-line suction and subglottic suctioning, and maintenance of endotracheal tube cuff pressure at 20-30 mmHg. The bundle compliance and VAP rates were then followed. RESULTS: A total of 3665 patients received mechanical ventilation, and there were 9445 monitored observations for bundle compliance. The total bundle compliance before and after initiation of the VAP team was 90.7% and 94.2%, respectively (P < .001). The number of VAP episodes decreased from 144 during 2008-2010 to only 14 during 2011-2013 (P < .0001). The rate of VAP decreased from 8.6 per 1000 ventilator-days to 2.0 per 1000 ventilator-days (P < .0001) after implementation of the care bundle. CONCLUSIONS: This study suggests that systematic implementation of a multidisciplinary team approach can reduce the incidence of VAP. Further sustained improvement requires persistent vigilant inspections.

Investigation of High-Energy Ion-Irradiated MA957 Using Synchrotron Radiation under In-Situ Tension.

In this study, an MA957 oxide dispersion-strengthened (ODS) alloy was irradiated with high-energy ions in the Argonne Tandem Linac Accelerator System. Fe ions at an energy of 84 MeV bombarded MA957 tensile specimens, creating a damage region ~7.5 µm in depth; the peak damage (~40 dpa) was estimated to be at ~7 µm from the surface. Following the irradiation, in-situ high-energy X-ray diffraction measurements were performed at the Advanced Photon Source in order to study the dynamic deformation behavior of the specimens after ion irradiation damage. In-situ X-ray measurements taken during tensile testing of the ion-irradiated MA957 revealed a difference in loading behavior between the irradiated and un-irradiated regions of the specimen. At equivalent applied stresses, lower lattice strains were found in the radiation-damaged region than those in the un-irradiated region. This might be associated with a higher level of Type II stresses as a result of radiation hardening. The study has demonstrated the feasibility of combining high-energy ion radiation and high-energy synchrotron X-ray diffraction to study materials' radiation damage in a dynamic manner.

Induced growth of dendrite gold nanostructure by controlling self-assembly aggregation dynamics.

Self-assembly of gold nanoparticles (AuNPs) is an important growth mode for fabricating functional materials. In this work we report a dendrite structure formed by slowing down the aggregation dynamics of AuNPs self-assembly. The obtained results show that the aggregation dynamics is dominated by the Reaction Limited Aggregation Model (RLA) more than the Diffusion Limited Aggregation Model (DLA). In which the repulsion due to electrostatic forces is dominant by the Van Der Walls attraction forces, and low sticking probability of nanoparticles. The aggregation dynamics of AuNPs can be slowed down if the water evaporation of the drop casted colloidal AuNPs on a quartz substrate is slowed. Slowing down the evaporation allows electrostatic repulsion forces to decrease gradually. At certain point, the attraction forces become higher than the electrostatic repulsion and hence cluster aggregation take place slowly. The slow aggregation dynamics allows the nanoparticles to sample all possible orientation in the sticking site, searching for the lowest energy configuration. The size distribution of the nanoparticles in liquid is confirmed using dynamic light scattering based on Stokes-Einstein equation for diffusion coefficient in water. X-ray and photoluminescence (PL) spectra of the sample after aggregation showed a shift which is related to the aggregation compared with non-aggregated colloidal nanoparticles in the solution. The study shows that dendrite self similar structure can be formed by slowing down the aggregation dynamics of nanoparticles as a result of minimizing the Helmholtz free surface energy of the system.

Mitochondrial complex II is a source of the reserve respiratory capacity that is regulated by metabolic sensors and promotes cell survival.

The survival of a cell depends on its ability to meet its energy requirements. We hypothesized that the mitochondrial reserve respiratory capacity (RRC) of a cell is a critical component of its bioenergetics that can be utilized during an increase in energy demand, thereby, enhancing viability. Our goal was to identify the elements that regulate and contribute to the development of RRC and its involvement in cell survival. The results show that activation of metabolic sensors, including pyruvate dehydrogenase and AMP-dependent kinase, increases cardiac myocyte RRC via a Sirt3-dependent mechanism. Notably, we identified mitochondrial complex II (cII) as a target of these metabolic sensors and the main source of RRC. Moreover, we show that RRC, via cII, correlates with enhanced cell survival after hypoxia. Thus, for the first time, we show that metabolic sensors via Sirt3 maximize the cellular RRC through activating cII, which enhances cell survival after hypoxia.

Diagnostic accuracy of a screening electronic alert tool for severe sepsis and septic shock in the emergency department.

BACKGROUND: Early recognition of severe sepsis and septic shock is challenging. The aim of this study was to determine the diagnostic accuracy of an electronic alert system in detecting severe sepsis or septic shock among emergency department (ED) patients. METHODS: An electronic sepsis alert system was developed as a part of a quality-improvement project for severe sepsis and septic shock. The system screened all adult ED patients for a combination of systemic inflammatory response syndrome and organ dysfunction criteria (hypotension, hypoxemia or lactic acidosis). This study included all patients older than 14 years who presented to the ED of a tertiary care academic medical center from Oct. 1, 2012 to Jan. 31, 2013. As a comparator, emergency medicine physicians or the critical care physician identified the patients with severe sepsis or septic shock. In the ED, vital signs were manually entered into the hospital electronic heath record every hour in the critical care area and every two hours in other areas. We also calculated the time from the alert to the intensive care unit (ICU) referral. RESULTS: Of the 49,838 patients who presented to the ED, 222 (0.4%) were identified to have severe sepsis or septic shock. The electronic sepsis alert had a sensitivity of 93.18% (95% CI, 88.78% - 96.00%), specificity of 98.44 (95% CI, 98.33% - 98.55%), positive predictive value of 20.98% (95% CI, 18.50% - 23.70%) and negative predictive value of 99.97% (95% CI, 99.95% - 99.98%) for severe sepsis and septic shock. The alert preceded ICU referral by a median of 4.02 hours (Q1 - Q3: 1.25-8.55). CONCLUSIONS: Our study shows that electronic sepsis alert tool has high sensitivity and specificity in recognizing severe sepsis and septic shock, which may improve early recognition and management.

Improving the care of sepsis: Between system redesign and professional responsibility: A roundtable discussion in the world sepsis day, September 25, 2013, Riyadh, Saudi Arabia.

This paper summarizes the roundtable discussion in September 25, 2013, Riyadh, Saudi Arabia as part of the World Sepsis Day held in King Abdulaziz Medical City, Riyadh. The objectives of the roundtable discussion were to (1) review the chasm between the current management of sepsis and best practice, (2) discuss system redesign and role of the microsystem in sepsis management, (3) emphasize the multidisciplinary nature of the care of sepsis and that improvement of the care of sepsis is the responsibility of all, (4) discuss the bundle concept in sepsis management, and (5) reflect on the individual responsibility of the health care team toward sepsis with a focus on accountability and the moral agent.

Liver abscesses in dromedary camels: Pathological characteristics and aerobic bacterial aetiology.

The study was carried out at Nyala abattoirs, South Darfur State, Sudan during a period from 2009 to 2011. Slaughtered camels (822) were examined for pathological changes of liver abscesses and identification of the involved aerobic bacteria. Grossly, a total of 111 (13.5%) liver abscesses were recorded in different camel ages; 90 (81.1%) were less than seven years old and 21 (18.9%) were more than seven years old. Histopathology of sectioned tissues revealed necrotic abscesses with infiltration of inflammatory cells, hydropic degeneration with swelling of hepatocytes comprising the sinusoid and different size of vacuoles in the hepatic cells. Proliferation of bile ducts with fibrous tissue and infiltration of inflammatory cells was also recorded. Investigation of bacteria revealed 90 aerobic isolates; they were identified to 52 (57.8%) gram positive cocci, 20 (22.2%) gram positive rods and 18 (20.0%) gram negative rods. Staphylococcus spp. (41.1%), Corynebacterium spp. (17.9%) and Streptococcus spp. (13.3%) were the most frequently identified bacteria involved in liver abscesses of camels in the region. Further studies are required to assess the pathogenicity of bacterial isolates from camel livers. This is particularly important from a public health perspective, since some people of Sudan are known to consume raw camel liver.

Development and evaluation of a live attenuated camelpox vaccine from a local field isolate of the virus.

A strain of camelpox virus (CMLV) isolated in the Sudan was attenuated by serial passage in Vero cell monolayers for use as a future vaccine strain. The safety and potency of passage 115 virus (designated Sudan CMLV/115) was tested. Camels inoculated with CMLV/115 showed no clinical disease or skin lesions, developed low-level antibodies and cell-mediated immune response and resisted challenge with virulent wild-type CMLV. Field testing of the candidate vaccine showed that the developed vaccine induces immune response and is safe for young and pregnant camels.

Building capacity for quality and safety in critical care: A roundtable discussion from the second international patient safety conference in April 9-11, 2013, Riyadh, Saudi Arabia.

This paper summarizes the roundtable discussion from the Second International Patient Safety Conference held in April 9-11, 2013, Riyadh, Saudi Arabia. The objectives of the roundtable discussion were to: (1) review the conceptual framework for building capacity in quality and safety in critical care. (2) examine examples of leading international experiences in building capacity. (3) review the experience in Saudi Arabia in this area. (4) discuss the role of building capacity in simulation for patient safety in critical care and (5) review the experience in building capacity in an ongoing improvement project for severe sepsis and septic shock.

In/Ga inter-diffusion in InAs quantum dot in InGaAs/GaAs asymmetric quantum well.

The Photoluminescence spectra (PL), their temperature and power dependence were investigated for the ground state in InAs quantum dots (QDs) embedded in InGaAs asymmetric quantum well (Asym. QW). In-atom segregation is well known phenomena in such structures, which result in altering the inter-atomic distances; as a consequence the thermo-dynamical parameters change as well, namely Debye temperature. The bigger value of Debye temperature for the studied sample with respect to the corresponding bulk value is attributed to In/Ga inter-diffusion during growth. The inter-diffusion process causes non-radiative defects in the sample. As a consequence, rapid decrease in the QDs integrated emission intensity as the temperature increases was occurred.

Peculiar temperature-power dependence of AlGaAs/GaAs multi quantum well.

The dependence of the integrated photoluminescence on the excitation power intensity in Al(0.3)Ga(0.7)As/GaAs multi quantum well is studied. Four peaks are found in the photoluminescence spectra, which are corresponding to the four quantum wells in the sample. The temperature dependence of the exponent alpha of the power law shows peculiar behavior for the quantum well of width 11.2 nm (peak C). The value of the exponent alpha exceeds the quadratic value predicted by the steady state model near room temperature. All other peaks shows linear dependence in the low temperature range which switches to super linear in the high temperature range with values of alpha less than 2. Carriers thermal capture and re-trapping is discussed. The presented results are a sign of thermal dissociation of exciton in quantum well near room temperature. The peculiar behavior is attributed to the excess flow of the charge carriers to this QW by thermal escape from other QWs, and also due to excess free carriers because of exciton dissociation.