Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

New heavy aggregate for offshore petroleum pipeline concrete coating Central West Sinai, Egypt

In this paper the local materials used in concrete mix are studied in a manner that they can resist the aggressive marine environment and mechanical damage, which can occur at several stages during transportation, construction and installation of the pipelines. In earlier studies we succeeded in finding the Egyptian ilmenite ore adequate for concrete weight coating and already utilized for many pipeline projects in Egypt. According to the presence of about 30% titanium oxides in ilmenite composition which may be extracted to be used in others strategically fields, the object of this paper is to study and evaluate the mechanical, chemical and physical properties of another local hematite high density iron ore to be used in subsea concrete weight coating for offshore petroleum pipelines. The results indicate that the local material of Um Bogma hematite iron ore can substitute both imported iron ore and local ilmenite from Abu Ghalaga in this field to reduce the cost effective and increased economical value of local ores. Laboratory and field tests were conducted for the hematite ore forming a concrete mix, composed of hematite ore, cement and fresh water according to international concrete coating specification requirements, the ore produces a concrete mix with 190–195 pcf minimum dry density and compressive strength, after 28 days of hydration, varying from 40 to 45 N/mm2 (400–450 kg/cm2) which comply with the international standards and specifications of submarine petroleum pipeline coating. In addition, local hematite shows superior results than local ilmenite and achieves 190 pcf instead of 180 pcf in case of using ilmenite

Upgrading offshore pipelines concrete coated by silica fume additive against aggressive mechanical laying

Studies have been carried out to investigate the possibility of utilizing a broad range of micro-silica partial additions with cement in the production of concrete coating. This study investigated the strength properties and permeability of micro-silica concrete to achieve resistance toward concrete cracking and damage during laying. The chemical composition of micro-silica (silica fume) was determined, and has been conducted on concrete mixes with additions of 3 up to 25% by weight of cement in concrete. Properties of hardened concrete such as compressive strength, flexural strength, and permeability have been assessed and analyzed. Cubic specimens and beams were produced and cured in a curing tank for 7 and 28 days. Testing results have shown that additions of silica fume to cement between 5% and 7%, which acts as a filler and cementations material, developed high flexural and compressive strength with reduction of permeability

Improving the performance of clay from Gabal Um Qumar as drilling mud

The main component of water base drilling fluids to perform common properties that facilitate safe and satisfactory drilling is bentonite operations. This paper represents composition and treatment capability of clays collected from clayston quarries in Gabal um Qumar north Cairo-Ismailia Desert Road, Egypt for its application as water base drilling mud. Chemical analysis, XRD and particle size distribution showed that these clays consist of montmorillonite. The rheological properties of the prepared suspension from these clay samples and its activation products by using chemicals and polymers were investigated. Results of untreated samples indicate that they cannot be used as a drilling mud but after activation processes by soda ash, Carboxi Methyl Cellulose (CMC) and Drispac Polymer significant changes were observed in yield and rheological properties. Accordingly this type of clay after activation by polymer can be classified as sub-bentonite and classified between bentonite grade and medium bentonite grade that can be used as drilling mud for medium depth wells

Evaluation of Egyptian bentonite and nano-bentonite as drilling mud

Nano-particles of bentonite have been prepared by nano-grinding. The nano-bentonite was characterized by X-ray fluorescence analysis (XRF), X-ray powder diffraction (XRD), thermal gravimetric analysis (TGA) and Transmission electron microscopy (TEM). The bentonite particles had been ground to the size ranging from 4 to 9 nm. Both natural and nano-bentonite were evaluated as drilling mud. The evaluation involved the study of the rheological properties, filtration and gel strength before and after treatment with viscosities and filter loss agent, and compared with the American Petroleum Institute API bentonite. With decreasing the grain size of bentonite to the nano-scale, the results were not satisfied to the API -standard

Investigation of some locally water-soluble natural polymers as circulation loss control agents during oil fields drilling

Eliminating or controlling lost circulation during drilling process is costly and time-consuming. Polymers play an important role in mud loss control for their viscosity due to their high molecular weight. In this paper, three natural cellulosic polymers (carboxymethyl cellulose, guar gum and potato starch) were investigated as lost circulation control material by measuring different filtration parameters such as; spurt loss, fluid loss and permeability plugging tester value according to the American Petroleum Institute (API) standard. The experiments were conducted in a permeability plugging apparatus (PPA) at a differential pressure of 100 and 300 psi, using 10, 60 and 90 ceramic discs. From the obtained data, it was found that the 0.1% from the carboxymethyl cellulose exhibited the best results in the filtration parameters among 0.3% guar gum and 0.6% potato starch. At the same time the carboxymethyl cellulose (CMC) enhanced the rheological properties of the drilling mud better than the two other used natural polymers in the term of gel strength, thixotropy, plastic and apparent viscosity. These results were discussed in the light of the adsorption and micellar formation

Enhancement of anti-corrosion and mechanical properties of alkyd-based protective paints for steel petroleum structures incorporating natural limonite pigment

In the present approach, natural limonite iron oxide samples from Baharyia Oasis areas have been collected and ground to the micro-sized scale to be used as pigment for upholding the corrosion resistance behavior and mechanical performance properties of protective paints for steel petroleum structures. The assessment procedure includes measuring of specific gravity, moisture content, oil absorption, particle size distribution, particle shape, pH value, soluble in water, hardness, powder color and chemical composition by XRF analysis of limonite pigment particles. X-ray diffraction (XRD) analysis was implemented to assure the phase identification of the crystalline limonite pigment particles. Dynamic light scattering (DLS) measurements were accomplished to measure the particle size distribution and Zeta-potential of these particles in suspension. Amorphous and lamellar morphology of limonite particles was manifested by scanning electron microscopy (SEM) micrographs. EDX investigation was employed to give a semi-quantitative analysis and the chemical composition of limonite pigment. Different alkyd-based coating formulations were modified using various uniformly dispersing amounts of the processed limonite pigment particles as bi-functional modifier. The anti-corrosion performance properties of the considered limonite modified coating formulations against unmodified blank coating were studied by accelerated corrosion experiment (salt spray chamber) after 500 h exposure in 5% NaCl solution. The obtained results revealed a significant improvement in the rust grade, blistering size, color tolerance and adhesion performance of limonite modified coated steel films compared to unmodified conventional coating. To confirm the previous concept, weight loss method was performed. The mechanical performance properties for these films were investigated by adhesion cross-cut, bend and impact coating tests to confirm their application efficiency. From the recorded data it was found that, the adhesion properties, elongation character and resistance to rapid deformation of these coatings increased significantly to the steel surface with increasing the limonite pigment (%) by weight in the coating formulation. The results obtained compared with the ASTM and paint handbooks and found satisfactory for producing color paint pigment

Impact of barite and ilmenite mixture on enhancing the drilling mud weight

It is common knowledge in the technology of drilling fluids, monitoring of the drilling mud weight is critical in developing a mud system that yields good well stability. Alternative weighting materials should be in demand to offer superior properties such as barite, available in sufficient reserves to meet field requirements and be competitively priced. A weighting material that can be sourced locally to substitute barite would be a good innovation in the drilling industry. The present work was performed for enhancement the weighting of the drilling fluids by using mixture of barite and ilmenite. Micro-sized ilmenite ore (FeTiO3) particles were obtained by a direct solid phase milling process to replace a certain percentage of barite as weighting material of the drilling mud. X-ray diffraction (XRD) analysis was carried out to underline the phase identification of the crystalline ilmenite, used drilling mud weighting agent as barite and Na-bentonite particles. The lamellar shape and the arrangement in overlapping plates of ilmenite particles, Platy-like shaped Na-bentonite grains against sub-angular and square-shaped barite particles were confirmed by scanning electron microscope (SEM) technique. Three mud samples with different densities were prepared which be made up of fresh water, sodium bentonite and weighting material. The weighting materials were added up to the mud separately to form the required mud density ranges between 8.65 and 18 lb/gal. The first sample was water-based mud with barite; second sample was water-based mud with local ilmenite ore and third sample was water-based with barite and ilmenite in which were added in parts as 50:50 by ratios. These samples were investigated at different temperatures (normal, 120, 160, 180 °F) and the employed mud density range to determine solid content, density, rheological properties and filtration losses. The study showed that the rheological properties of barite/ilmenite mixture were found to give comparable results as barite and has the potential to be used as alternative weighting material especially in a heavier drilling mud. Two significant advantages could be observed through using the mixture; it produces lower solids content and fluid loss which in turns reduces the formation damage, respectively. Keywords: Drilling mud weight, Ilmenite ore, Barite/ilmenite mixture, Rheology, XRD, SE

Influence of surface modified nanoilmenite/amorphous silica composite particles on the thermal stability of cold galvanizing coating

The present approach investigates the use of novel nanoilmenite/amorphous silica composite (NI/AS) particles fabricated from ilmenite nanoparticles (FeTiO3 NPs) and synthesized amorphous silica grains to improve thermal stability of the cold galvanizing coating. Transmission electron microscopic (TEM) images demonstrated that both nanoilmenite and nanocomposite particles were of flaky-like nature and the average diameter of the particles is 20 nm. The lamellar shape of the nanocomposite and spherical nature of Zn-dust particles were illustrated by scanning electron microscopy (SEM) micrographs. Different alkyd-based cold galvanizing coating formulations were modified using uniformly dispersing various amounts of the processed nanocomposite particles as a modifier to form some engineering nanocomposite coatings. Thermal stability of the nanocomposite and Zn-dust particles was determined by thermo-gravimetric analysis (TGA). From the obtained results it could be observed that the weight loss (%) as a feature of the thermal stability in case of the nanocomposite particles was 2.9 compared to 85.9 for Zn-dust powder grains. Derivative thermo-gravimetric (DTG) measurements were done under nitrogen atmosphere for the cured cold galvanizing coating samples heated from room temperature to 1000 °C. The obtained results revealed that the maximum decomposition temperature point in the third degradation step for 6% nanocomposite surface modified cured sample (CG-F) was detected at 693 °C and was less value for unmodified conventional cold galvanizing coating (CG-A) at 612 °C. The increase in thermal stability with increasing the concentration of nanocomposite particles could be mainly attributed to the interface surface interaction between the nanocomposite particles and alkyd resin matrix in which enhancing the inorganic-organic network stiffness by causing a reduction in the total free spaces and enhancement in the cross-linking density of the cured film then, requires high energy to cleave it. Keywords: Nanoilmenite/amorphous silica composite, Cold galvanizing coating, Thermal stability, TEM, TGA, DT