Search Results (142)

Phosphorus Adsorption Media (PAM) is an emerging technology used to remove phosphorus from water and has the advantage of minimal operation and maintenance support when compared to biological and chemical treatments. Although the capacity of PAM has been researched, the understanding of important design parameters for PAM is lacking. Therefore, this study focused on determining critical design parameters for PAM, such as hydraulic loading, Empty Bed Contact Time (EBCT), and its impact on the media’s capacity. In addition, the regeneration potential of PAM and the mathematical model for predicting the exhaustion of PAM are discussed to provide a practice tool for designing PAM. The results indicate that hydraulic loadings do not show a strong effect on PAM performance, as there are no significant differences between hydraulic loadings of 0.05, 0.12, and 0.22 mL/min/cm². This study also showed that the higher EBCT (190 min) has higher removal rates than the lower EBCT (60 and 90 min). This indicated that EBCT is a critical design parameter for PAM. Laboratory studies demonstrating the regeneration of exhausted media by washing with a caustic solution have been conducted, and a qualitative study showed that exhausted media can be used in hydroponics. Batch testing showed that over 99% of the sorbed phosphorus was eliminated after six cycles of the regeneration process. Full article

In open-pit bench pre-splitting blasting, the interaction of explosion-induced stress waves between blast holes is essential for safeguarding the rear rock mass. This study utilizes the caustic method to examine the propagation velocity of explosion-induced cracks, the stress intensity factor at the crack tip, and the final morphology of cracks between adjacent blast holes with varying delay times. Field pre-splitting blasting experiments were carried out to validate these effects. The experimental results reveal that, for short inter-hole delay times (0–12 μs), a “hook-like” crack intersection zone emerges between blast holes. Changes in delay time influence the patterns of crack propagation, leading to deviations in the propagation direction of cracks in subsequent blast holes due to the combined effects of stress waves and cracks from preceding holes. The fracture mechanism evolves from pure Mode I (tensile) to a mixed Mode I-II (tensile-shear). Vibration signals from the field blasting tests were analyzed using the variational mode decomposition (VMD) method. The findings indicate that optimized inter-hole delay times can reduce peak particle velocity (PPV) by 18.7–23.4% compared to simultaneous initiation, thereby significantly minimizing damage to the rear rock mass, a crucial factor for maintaining slope stability. Full article

Background: Oesophageal perforation (OP) is a life-threatening condition requiring prompt diagnosis and treatment. Mortality is influenced by several factors, such as aetiology, defect location, comorbidities, age, and delays in treatment. This study reviews patients with OP undergoing surgery, analysing mortality risks and the impact of timing on surgical outcomes. Methods: Medical records of 45 patients surgically treated for OP across three tertiary centers were analysed. Results: Of the 45 patients, 31 were male (68.88%) and 14 were female (31.11%), with a mean age of 66.00 ± 17.75 years. Pre-operative CT was performed in all patients, and 18 (40%) underwent oesophagogastroduodenoscopy. As many as 25 patients (55.55%) presented within 24 h, 10 (22.22%) within 24–72 h, and 10 (22.22%) after 72 h. Symptoms included pain, vomiting, fever, dysphagia, and subcutaneous emphysema. Foreign body ingestion and Boerhaave’s syndrome were the leading causes (33.33% each), followed by caustic ingestion (17.77%) and iatrogenic and traumatic cases. Treatments included primary repair, debridement, oesophagectomy, and oesophagogastrectomy. Primary repair was performed in 22 cases (48.88%), and muscle flaps reinforced 11 of these. Direct repair showed the highest success rate when performed within 24 h. Thirty patients (66.66%) experienced complications, including respiratory failure, oesophagopleural fistula, and sub-stenosis. The hospital stay average was 36.34 ± 35.03 days. Nine patients underwent same-session/two-stage gastroplasty or retrosternal coloplasty for reconstruction, with complications including stenosis and leaks. Six patients (13.33%) died within the first 24 h after surgery, primarily due to severe comorbidities (three (50%) were octogenarians). Conclusions: OP is a life-threatening condition with high mortality. Primary repair is the preferred treatment. Oesophagectomy and gastrectomy are reserved for extensive lesions. Muscle flaps can reinforce sutures in cervical and thoracic perforations. Mortality is mainly influenced by the severity of the patient’s clinical picture and comorbidities, rather than by time and type of treatment. Full article

Background/Objectives: Ostomy creation surgery is a common intervention for patients with conditions such as colorectal cancer, ulcerative colitis, Crohn’s disease, or acute events like trauma and gastrointestinal perforation. Individuals with an ileostomy face unique challenges when managing their new ostomies due to the liquid caustic nature of the effluent, increasing the likelihood of leakage and peristomal skin complications (PSCs). This sub-analysis evaluates the prevalence of leakage and PSCs in a cohort of individuals with a new ileostomy and examines the risk of leakage of different ostomy pouching systems and their impact on leakage and PSCs. Methods: This sub-analysis examined a cohort of 98 patients from a previously published retrospective chart review of stoma-creation surgeries at the University of Pittsburgh Medical Center. Data on pouching system selection, leakage, and PSCs were collected from electronic medical records and evaluated across 479 pouch changes. Two main barrier pouching systems were analyzed: elastic tapeless border (ETB) and ceramide-infused tape-border (CIB) barriers. Statistical analyses using generalized linear mixed models assessed the risk of leakage for each barrier type and controlled for significant differences in the sub-groups. Results: The prevalence of leakage in the ileostomy cohort was 19%, with the prevalence of leakage increasing over successive pouch changes. The ETB sub-group experienced a significantly lower risk of leakage (13.7%) compared to CIB (29.3%), reflecting a 53.2% lower risk of leakage with ETB (p = 0.03; OR 2.45). Conclusions: This sub-analysis of ileostomy patients confirms that ETB significantly reduces the risk of leakage in this more difficult to manage population compared to CIB, a clinically important consideration in PSC development and overall ostomy management. Evidence-based selection of ostomy barriers can improve patient outcomes, enhance quality of life, and reduce healthcare resource utilization. Full article

Upper Cretaceous carbonate rocks in Jordan are the main resources for construction and paint-related industrial applications. This study evaluates the elemental composition, mineralogy, and petrography of two main geological formations from two localities in northern Jordan (Hallabat, Turonian age, and Ajlun, Santonian–Campanian age) to shed light on their composition, depositional environments, and potential industrial end uses. The elemental composition of the Hallabat Wadi Sir Limestone (WSL) Formation indicates notable variability between the middle and upper parts of the WSL carbonates in the area, with higher CaO content in the middle part (mean 55 wt.%) and higher silica content observed in the upper part (mean 2 wt.%) compared with the middle part (mean 0.9 wt.%). Meanwhile, analysis of the elemental composition of the Ajlun Amman Silicified Limestone (ASL) Formation indicates that the CaO content is relatively higher in the upper part (mean 56 wt.%). In addition, the lower part is more influenced by detrital input when compared with the upper part of the studied section, in contrast to the Hallabat WSL Formation. Petrographic analysis demonstrates that the WSL and ASL samples are predominantly micritic limestone. The XRD results for the Hallabat WSL and Ajlun ASL show that the mineralogical composition is dominated by calcite (CaCO₃). Statistical and PCA analyses also confirm these variabilities between the two sites, indicating that all samples from both sites were deposited under variable hydrodynamic and environmental conditions that affected their physical and chemical composition. The results show that all studied samples are in the range of pure limestone and can be used for specific industrial applications in addition to their current uses, including those in the pottery and porcelain ware, soda ash and caustic soda, steel industry, sugar, and textile production industries, thus contributing to the economic resources in Jordan. Full article

Background: Over the last two decades, therapy for benign esophageal strictures has shifted from empirical dilatations and surgery to evidence-based and complex endoscopic and surgical procedures, aiming to achieve long-term esophageal patency. Aim: The purpose of our study is to provide descriptive evidence regarding the appropriate tailored medical, endoscopic, and surgical management of benign esophageal strictures. Methods: This retrospective study includes patients with benign esophageal strictures; the data collected encompass the complete patient profiles, detailed etiologic and anatomic workups of the strictures, comprehensive imaging, as well as management and follow-up details. Technical and clinical success rates, adverse events, stricture patency, and the need for additional therapy have been evaluated. Results: Most of the strictures (80.2%) were complex, requiring advanced techniques for management. The primary treatment involved endoscopic dilation, performed with Savary-Gillard bougie dilators in 76.7% of cases and pneumatic balloon dilators in 23.3% of cases. Clinical success was achieved in 95.3% of patients, with a significant improvement in the Ogilvie dysphagia score. Patients with caustic strictures required repeated dilations over the years, compared to shorter intervals for peptic strictures. Adverse events were minimal (e.g., perforation 2.3% and bleeding 4.7%) and managed predominantly endoscopically. Refractory strictures (16.3%) required advanced interventions, including fully covered self-expandable metallic stents (fc-SEMS) and corticosteroid injections. Conclusions: Both our data and the current literature support the use of tailored endoscopic strategies as the first-choice options for managing benign esophageal strictures. Our results strongly suggest against one-size-fits-all therapeutic alternatives. Full article

This article discusses the design of a high-performance quasi-optical mode converter for the $T{E}_{33,12}$ mode at 210 GHz. The conversion process is challenging due to a caustic-to-cavity radius ratio of approximately 0.41. The mode converter employs an optimized dimpled wall launcher, analyzed using coupling mode theory with twenty-five coupled modes, compared to the usual nine modes and optimized reflector systems, to effectively address the conversion challenge.Electromagnetic field analysis within the launcher wall was optimized using MATLAB R2021b. The radiation fields from the launcher were analyzed in free space using Gaussian optics and vector diffraction theory. The mirror system consists of a quasi-elliptical mirror, an elliptical mirror, and phase-corrected parabolic mirrors. Following phase correction, the output window achieved a scalar Gaussian mode content of 99.0% and a vector Gaussian mode content of 97.4%. Full article

This study investigates public perceptions in Texas regarding two common calf disbudding methods used in dairy farming: caustic paste and hot iron. With growing consumer interest in humane animal treatment, understanding the preferences for these methods provides insights into public expectations of welfare in agricultural practices. The study utilized an online survey distributed to Texas residents via the Centiment research platform, assessing preferences, demographic influences, and the impact of scientific information on perceptions. Results, from 511 participants, indicated a stronger preference for caustic paste, especially among women and participants with higher education levels, while hot iron was favored more by men. Dietary habits, such as seafood and cheese consumption, also influenced preferences, with higher consumption linked to a preference for caustic paste. Viewing images of the disbudding techniques affected the willingness to purchase, consume, and serve beef, with hot iron prompting a greater negative response. The findings suggest that public knowledge and awareness can significantly impact perceptions surrounding animal welfare practices and that education could play a critical role in aligning consumer preferences with humane agricultural practices. These insights are valuable for the dairy industry, informing practices that are more aligned with public expectations and supporting the promotion of welfare-oriented disbudding methods. Full article

Membrane contactors have proved to be effective for recovering ammonia from wastewater by absorbing it into a trapping solution. This study compares the performance of sulfuric acid and citric acid as trapping solutions in a pilot-scale plant for recovering ammonia from sludge digestion liquors using membrane contactors in a liquid–liquid configuration operating at pH 10 and a temperature of 37 °C and using ultrafiltration (UF) technology as pretreatment. The performance of the process using sulfuric acid at a lower pH (9.5) and temperature (30 °C) was also studied, as well as the advantage of including a CO₂-stripping module in the process. The ammonia elimination efficiency was 88% and 86% when using sulfuric acid and citric acid, respectively. The nitrogen concentration of the produced ammonium sulfate and ammonium citrate reached 23.2 and 14.7 g NH₃-N·L⁻¹, respectively. The ammonia elimination efficiency when using sulfuric acid decreased to 49% when decreasing the pH to 9.5 and to 85% when decreasing the temperature to 31 °C. UF technology was able to reduce the concentration of suspended solids by 90% and the chemical oxygen demand by 37%. However, the UF membranes for the pretreatment and the membrane contactors for ammonia recovery had to be constantly cleaned with acid due to scaling, which significantly increased maintenance efforts. The CO₂-stripping module reduced the consumption of the caustic soda solution by 23% for increasing the pH level of the treated water. Finally, the specific energy consumption of the plant was 8 kWh·m⁻³. Full article

Emergency endoscopy is an activity that must be guaranteed 7 days a week and 24 h a day. The pathologies of endoscopic interest that require emergency intervention are mainly hemorrhages of the upper digestive tract, the removal of foreign bodies, and the ingestion of caustics. The emergency endoscopist must therefore be experienced in the management of these pathologies. Nowadays, however, we know that even some biliary tract pathologies must be managed within a variable period between 12 and 72 h, in particular acute cholangitis (Ach), acute biliary pancreatitis (ABP), biliary duct leaks (BDLs), and acute cholecystitis (AC). If, on one hand, there is little awareness among doctors about which pathologies of the biliary tract really deserve urgent treatment, on the other, the international guidelines, although not uniformly, have acquired the results of the studies and have clarified that only severe Ach should be treated within 12 h; in other cases, endoscopic treatment can be delayed up to 72 h according to the specific condition. This obviously has a significant organizational implication, as not all endoscopists have training in biliary tract endoscopy, and guaranteeing the availability of a biliary endoscopist 24/7 may be incompatible with respecting the working hours of individual professionals. This review aims to evaluate which pathologies of the biliary tract really require an endoscopic approach in emergency or urgency and the organizational consequences that this can determine. Based on the guidelines, we can conclude that a daytime availability for urgent biliary tract procedures 7 days a week should be provided for the management of severe ACh. Patients with ABP, AC unfit for surgery, and not responsive to medical therapy or BDLs can be treated over a longer period, allowing its scheduling on the first available day of the week. Full article

African swine fever (ASF) is one of the most economically significant diseases of pigs caused by African swine fever virus (ASFV). Due to the lack of effective and safe vaccines, one of the crucial measures to protect farms from the introduction of the ASFV is to apply a strict regime of biosecurity and disinfection. However, in field conditions, the activity of disinfectants may be influenced by temperature, resulting in reduced activity or biodegradation (i.e., freezing or evaporating). The aim of this study was to evaluate the effect of a wide range of temperatures on the virucidal activity of selected active substances commonly used against ASFV. Eight active substances were tested, namely: sodium hypochlorite (1.0%), glutaraldehyde (0.1%), potassium peroxysulfate (0.5%), caustic soda (1.0%), phenol (1.0%), acetic acid (3.0%), benzalkonium chloride (1.0%), and formaldehyde (0.4%). The virucidal activity of each compound was tested at different temperatures (21, −10, and −20 °C for 30 min) and compared to the initial virus titer under the same temperature conditions. Exposure to a range of temperatures did not significantly affect the virucidal efficacy of tested active substances against ASFV. Most of the evaluated substances had reduced virus titers ≥ 4 log₁₀, regardless of the temperature. However, two of them (benzalkonium chloride and acetic acid) were sensitive to sub-zero temperatures, showing a lack of the required 4 log₁₀ virus titer reduction. The conducted study showed that temperature could hamper the virucidal effect of selected substances (i.e., benzalkonium chloride and acetic acid), showing their moderate efficacy against ASFV −10 °C and −20 °C. The results suggest that extreme caution should be taken while applying these substances at sub-zero temperatures. The other substances had no significant sensitivity to the temperature range. Nevertheless, in the case of freezing the agent, insufficient penetration of the disinfected surface may occur, which may result in an ineffective disinfection process. Full article

This paper focuses on the possibility of using phosphogypsum, which is a residue from the production of orthophosphoric acid as an additional source of calcium and the use of spent caustic as an alkaline activator for production of ceramic materials in construction industry. The use of the above-mentioned waste will allow to increase fraction of calcium, sodium and silicate needed for the geopolymerization process and improve properties of material. This review presents a description of the geopolymerization process and the influence of alkaline activator on the reactions occurring in ceramic materials. Collected information, which confirm the possibility of using post-production waste from chemical industry as components for the production of building materials. Full article

The diaspore is a typical representative of bauxite resources in China, which is the primary raw material for the Bayer process in alumina production, particularly in regions such as Shanxi, Guangxi, Guizhou, and Henan. Clarifying the phase transformations and reaction mechanisms of the silicon-containing minerals during the Bayer leaching process of diaspore is essential for improving the efficiency of alumina production. This article focuses on montmorillonite, which is one of the silicon-containing minerals of diaspore-type bauxite, investigating the reaction mechanisms and phase changes of montmorillonite under the high-calcium sodium aluminate solution system by using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Magic Angle Spinning Nuclear Magnetic Resonance (MAS–NMR) and Fourier Transform Infrared Spectroscopy (FTIR). The results show that montmorillonite dissolved and transformed into Na₆(AlSiO₄)₆ (hydrated sodium aluminosilicate) under the high-calcium sodium aluminate solution system, and calcium oxide and sodium aluminate in the solution reacted to form (CaO)₃Al₂O₃(H₂O)₆ (hydrated calcium aluminate). With the increase of reaction temperature, caustic alkali concentration (N_k), and reaction time, hydrated calcium aluminate and hydrated sodium aluminosilicate react and transform into Ca₃Al₂SiO₄(OH)₈ (hydrogarnet). Under the optimal reaction conditions of a 120 min reaction time, a temperature of 240 °C, an N_k of 240 g/L, and a CaO–to–SiO₂ mass ratio (C/S) of 3.5:1, the montmorillonite reaction degree can reach a maximum of 93.71%. Full article

When processing low-quality gibbsite–kaolinite bauxites, technologies that involve different methods of mechanical and chemical enrichment with the separation of a difficult-to-utilize fine kaolinite fraction for disposal are used. Before production, problems related to waste storage and disposal arise. To solve the problem of utilization, it is necessary to develop an effective technology for the selective processing of the kaolinite fraction. The efficiency of the technology will depend on the quality of pretreatment of raw materials prior to processing for Al₂O₃ extraction. Preliminary preparation of kaolinite fraction is associated with the maximum removal of excess silica during chemical enrichment by treatment with an alkaline solution. The presence of silica reduces the quality of final alumina products and requires a large consumption of reagents during the desiliconization of aluminate solutions. During the chemical enrichment of kaolinite fraction in alkaline solution, a serious problem of the co-dissolution of Al₂O₃ with silica arises. The solution to this problem can be the transformation of phase composition with the transformation of kaolin into a chemically resistant compound corundum, which will create conditions for the selective removal of silica. Kazakhstan’s alumina refinery, Pavlodar Aluminum Smelter, processes low-quality gibbsite–kaolinite bauxite from the Krasnogorsk deposit. To improve the quality of bauxite, preliminary gravity enrichment is carried out to separate the kaolinite fraction to a quantity greater than 50%. The purpose of this work was to study the possibility of the selective processing of the kaolinite fraction via various techniques, including preliminary thermal transformation, through sintering, chemical enrichment, autoclave leaching in a circulating aluminate solution, and low-temperature desiliconization, to obtain a solution for decomposition. As a result of this study, the possibility of obtaining a corundum phase after sintering at a temperature of 900–1000 °C was established, which made it possible to obtain 58.8% chemical enrichment through the extraction of SiO₂ into solution. Further use of the enriched kaolinite fraction in autoclave leaching in a circulating aluminate solution with low-temperature desiliconization made it possible to obtain an aluminate solution with a caustic modulus of 1.65–1.7, which is suitable for decomposition. Full article

Cutaneous leishmaniasis is one of the most commonly diagnosed dermatological condition in travel medicine after diarrhoeal diseases and febrile status. The disease is transmitted by Phlebotomus and Lutzomyia sandflies. It appears in various clinical forms, the most common of which is a painless ulcer with raised edges, usually present on exposed parts of the body on the side where the insect bite occurred. Annually, over a million new cutaneous leishmaniasis (CL) cases are reported globally. We present two cases of affliction, the first occurring in Patient 1, who attempted treatment through the Kambo cleanse in South America, which is considered a toxic, even life-threatening, procedure. It involves the subcutaneous application of a substance dangerous to humans derived from the surface mucus of a frog. Patient 2 applied caustic ointments, a fruitarian diet, and hyperbaric oxygen therapy in a private setting. After initial therapeutic failures caused by the patients’ unconventional treatment ideas, the causal treatment effect was satisfactory, demonstrating the efficacy of these treatments in resolving the infection when applied appropriately. Despite the typical CL presentation in both patients, their self-treatment course was unusual. It is worth noting that alternative, sometimes harmful, self-treatment initiatives by patients may be surprising and ineffective. Promoting knowledge about tropical diseases among travellers and medical staff is crucial to improving treatment outcomes. Full article