Hydrogen production by photoreforming of organic compounds

Productivity with respect to direct water photosplitting. Methanol is used here as model molecule to investigate the effect of catalyst composition and of substrate concentration on photocatalytic activity. Simple catalysts formulations were selected, in order to propose an easily scalable technology with a poorly expensive material. TiO2 with different structure (anatase, rutile and a mixture of them) was used as semiconductor, doped with a small amount of Au (0.1 wt%) to improve the lifetime of photogenerated charges. A new photoreactor was set up, with external irradiation that improves the scale up feasibility and possible future application with solar energy. Methanol conversion and hydrogen productivity increased with increasing methanol concentration up to 15 wt%. Rutile led to the highest conversion, but TiO2 P25 showed the highest hydrogen productivity. The best result was achieved by treating a 15 wt% methanol solution with 0.1 wt%Au/TiO2 P25, which led to 0.276 mol H2 h-1 kgcat-1

Comparison of Organ Dosimetry for Astronaut Phantoms: Earth-Based vs. Microgravity-Based Anthropometry and Body Positioning

The purpose of this study is to use NASA radiation transport codes to compare astronaut organ dose equivalents resulting from solar particle events (SPE), geomagnetically trapped protons, and free-space galactic cosmic rays (GCR) using phantom models representing Earth-based and microgravity-based anthropometry and positioning. Methods: The Univer sity of Florida hybrid adult phantoms were scaled to represent male and female astronauts with 5th, 50th, and 95th percentile heights and weights as measured on Earth. Another set of scaled phantoms, incorporating microgravity-induced changes, such as spinal lengthening, leg volume loss, and the assumption of the neutral body position, was also created. A ray-tracer was created and used to generate body self-shielding distributions for dose points within a voxelized phantom under isotropic irradiation conditions, which closely approximates the free-space radiation environment. Simplified external shielding consisting of an aluminum spherical shell was used to consider the influence of a spacesuit or shielding of a hull. These distributions were combined with depth dose distributions generated from the NASA radiation transport codes BRYNTRN (SPE and trapped protons) and HZETRN (GCR) to yield dose equivalent. Many points were sampled per organ. Results: The organ dos e equivalent rates were on the order of 1.5-2.5 mSv per day for GCR (1977 solar minimum) and 0.4-0.8 mSv per day for trapped proton irradiation with shielding of 2 g cm-2 aluminum equivalent. The organ dose equivalents for SPE irradiation varied considerably, with the skin and eye lens having the highest organ dose equivalents and deep-seated organs, such as the bladder, liver, and stomach having the lowest. Conclus ions: The greatest differences between the Earth-based and microgravity-based phantoms are observed for smaller ray thicknesses, since the most drastic changes involved limb repositioning and not overall phantom size. Improved self-shielding models reduce the overall uncertainty in organ dosimetry for mission-risk projections and assessments for astronaut

Improvements to the Ionizing Radiation Risk Assessment Program for NASA Astronauts

To perform dosimetry and risk assessment, NASA collects astronaut ionizing radiation exposure data from space flight, medical imaging and therapy, aviation training activities and prior occupational exposure histories. Career risk of exposure induced death (REID) from radiation is limited to 3 percent at a 95 percent confidence level. The Radiation Health Office at Johnson Space Center (JSC) is implementing a program to integrate the gathering, storage, analysis and reporting of astronaut ionizing radiation dose and risk data and records. This work has several motivations, including more efficient analyses and greater flexibility in testing and adopting new methods for evaluating risks. The foundation for these improvements is a set of software tools called the Astronaut Radiation Exposure Analysis System (AREAS). AREAS is a series of MATLAB(Registered TradeMark)-based dose and risk analysis modules that interface with an enterprise level SQL Server database by means of a secure web service. It communicates with other JSC medical and space weather databases to maintain data integrity and consistency across systems. AREAS is part of a larger NASA Space Medicine effort, the Mission Medical Integration Strategy, with the goal of collecting accurate, high-quality and detailed astronaut health data, and then securely, timely and reliably presenting it to medical support personnel. The modular approach to the AREAS design accommodates past, current, and future sources of data from active and passive detectors, space radiation transport algorithms, computational phantoms and cancer risk models. Revisions of the cancer risk model, new radiation detection equipment and improved anthropomorphic computational phantoms can be incorporated. Notable hardware updates include the Radiation Environment Monitor (which uses Medipix technology to report real-time, on-board dosimetry measurements), an updated Tissue-Equivalent Proportional Counter, and the Southwest Research Institute Radiation Assessment Detector. Also, the University of Florida hybrid phantoms, which are flexible in morphometry and positioning, are being explored as alternatives to the current NASA computational phantoms

A new eco-friendly initiative for last food mile delivery in urban areas

The last food mile delivery involves the final step of delivering food products to the end customers. By developing e-commerce channels, home delivery is considered the final mile of food delivery. However, although home food delivery has received much welcome from consumers, it is still one of the costliest and most polluting segments in the food supply chain, and its optimisation is highly felt. Thus, this paper proposes a new initiative to reduce the environmental impacts of home food deliveries from retailers in urban areas. Last food mile models for both the conventional approach in which each retailer has its own dark store and for a proposed approach in which all retailers have only one common dark store for home food delivery are developed. A Vehicle Route Problem with Time Window (VRPTW) and heterogeneous fleet are developed to minimise both CO2 emission and transportation cost simultaneously and implemented using a simulated annealing algorithm that is programmed in MATLAB software. The obtained results revealed that the proposed initiative's application can significantly impact the reduction of both CO2 emission and transportation costs

Prevalence and predictive factors for nosocomial infection in the military hospitals: A systematic review and meta-analysis

Background: To assess prevalence and predictive factors for Nosocomial Infection (NI) in the military hospitals. Methods: PubMed, Scopus, Cochrane and PreQuest databases were systematically searched for studies published between Jan 1991 and Oct 2017 that reported the prevalence of NI and predictive factors among military hospitals. We performed the meta-analysis using a random effects model. Subgroup analysis was done for heterogeneity and the Egger test to funnel plots was used to assess publication bias. Results: Twenty-eight studies with 250,374 patients were evaluated in meta-analysis. The overall pooled estimate of the prevalence of NI was 8 (95 6.0�9.0). The pooled prevalence was 2 (95 CI: 2.0�3.0) when we did sensitivity analysis and excluding a study. The prevalence was highest in burn unit (32) and ICU (15). Reported risk factors for NI included gender (male vs female, OR: 1.45), age (Age�65, OR: 2.4), diabetes mellitus (OR: 2.32), inappropriate use of antibiotics (OR: 2.35), received mechanical support (OR: 2.81), co-morbidities (OR: 2.97), admitted into the ICU (OR: 2.26), smoking (OR: 1.36) and BMI (OR: 1.09). Conclusion: The review revealed a difference of prevalence in military hospitals with other hospitals and shows a high prevalence of NI in burn units. Therefore careful disinfection and strict procedures of infection control are necessary in places that serve immunosuppressed individuals such as burn patient. Moreover, a vision for the improvement of reports and studies in military hospitals to report the rate of these infections are necessary. © 2021, Iranian Journal of Public Health. All rights reserved

Acetonitrile from Bioethanol Ammoxidation : Process Design from the Grass-Roots and Life Cycle Analysis

The growing interest for new routes to obtain acetonitrile led to the development of catalysts active toward the ammoxidation of various substrates. Among these, a C2 molecule such as ethanol represents a good choice in terms of atom economy and, being renewable, sets the basis for a long-term sustainable process. This paper describes a fully integrated, newly designed process for the production of acetonitrile from bioethanol, currently not present in the literature. The target is the production and purification of 10 kg/h of acetonitrile, unit of production used for calculations, obtained from ethanol, ammonia, and air as raw materials. All the byproducts, mainly ammonium bicarbonate and sodium cyanide, are considered marketable chemicals and represent an added value, instead of a disposal issue. Their optimized recovery is included in this flowsheet as a basis for the future economic assessment of the system. The process consumes CO2 without its direct emission. In principle, all the carbon atoms and 90% of the nitrogen atoms are turned into reaction products, and the main loss is gaseous N2. The process design has been performed by means of the Aspen PLUS process simulator, on the basis of literature data and other experimental results. In addition, for an evaluation of the potential benefits of the innovative biobased route, a life cycle analysis was carried out including all the stages involved in the bioacetonitrile production (from raw materials extraction up to the gate plant). The results were then compared with those achieved for the traditional fossil route (SOHIO process), showing a sensible decrease of the environmental burdens in terms of nonrenewable resources and damage to ecosystems (e.g., toxicity, climate change, etc.). Finally, a simplified sensitivity analysis was carried out by substituting the starting raw material for the production of bioethanol (corn) with other materials conventionally used worldwide, such as sugar cane and wood. The latter option seems to make the system more competitive in terms of carbon neutrality, thanks to the usage of the residual lignocellulosic fraction available on the market

Conforming to accreditation in Iranian hospitals

This paper examines the operation of an accreditation programme for hospitals in Iran. It explores the process of accreditation as a regulatory control system and analyses hospitals’ responses to this type of control. We draw on the notion of steering and argue that the accreditation system is transactional in nature. Our findings show that hospitals conform to the scheme, although they also resist some of its requirements. On a wider policy level, we suggest that accreditations offer the accreditor the opportunity to impact on how activities are undertaken, but hospitals require incentives in order to make the necessary organisational changes

A new practical method to evaluate the Joule-Thomson coefficient for natural gases

© 2017, The Author(s). The Joule–Thomson (JT) phenomenon, the study of fluid temperature changes for a given pressure change at constant enthalpy, has great technological and scientific importance for designing, maintenance and prediction of hydrocarbon production. The phenomenon serves vital role in many facets of hydrocarbon production, especially associated with reservoir management such as interpretation of temperature logs of production and injection well, identification of water and gas entry locations in multilayer production scenarios, modelling of thermal response of hydrocarbon reservoirs and prediction of wellbore flowing temperature profile. The purpose of this study is to develop a new method for the evaluation of JT coefficient, as an essential parameter required to account the Joule–Thomson effects while predicting the flowing temperature profile for gas production wells. To do this, a new correction factor, CNM, has been developed through numerical analysis and proposed a practical method to predict CNM which can simplify the prediction of flowing temperature for gas production wells while accounting the Joule–Thomson effect. The developed correlation and methodology were validated through an exhaustive survey which has been conducted with 20 different gas mixture samples. For each sample, the model has been run for a wide range of temperature and pressure conditions, and the model was rigorously verified by comparison of the results estimated throughout the study with the results obtained from HYSYS and Peng–Robinson equation of state. It is observed that model is very simple and robust yet can accurately predict the Joule–Thomson effect

Long-term evolution of an Oligocene/Miocene maar lake from Otago, New Zealand

Foulden Maar is a highly resolved maar lake deposit from the South Island of New Zealand comprising laminated diatomite punctuated by numerous diatomaceous turbidites. Basaltic clasts found in debris flow deposits near the base of the cored sedimentary sequence yielded two new ⁴⁰Ar/³⁹Ar dates of 24.51 ± 0.24 and 23.38 ± 0.24 Ma (2σ). The younger date agrees within error with a previously published ⁴⁰Ar/³⁹Ar date of 23.17 ± 0.19 Ma from a basaltic dyke adjacent to the maar crater. The diatomite is inferred to have been deposited over several tens of thousands of years in the latest Oligocene/earliest Miocene, and may have been coeval with the period of rapid glaciation and subsequent deglaciation of Antarctica known as the Mi-1 event. Sediment magnetic properties and SEM measurements indicate that the magnetic signal is dominated by pseudo-single domain pyrrhotite. The most likely source of detrital pyrrhotite is schist country rock fragments from the inferred tephra ring created by the phreatomagmatic eruption that formed the maar. Variations in magnetic mineral concentration indicate a decrease in erosional input throughout the depositional period, suggesting long-term (tens of thousands of years) environmental change in New Zealand in the latest Oligocene/earliest Miocene