Hard Deposits Research Articles

Reducing fat, oil, and grease (FOG) deposits formation and adhesion on sewer collection system structures through the use of fly ash replaced cement-based materials

The accumulation of fat, oil, and grease (FOG) deposits in sewer pipes reduces their conveyance and results in Sanitary Sewer Overflows (SSOs). Previous research has shown that concrete used in sewer lines is a significant source for calcium ion, which participates in the FOG deposit formation mechanism. However, no research has been conducted to understand the effect of calcium leaching from cement on FOG deposits formation and adhesion. This study quantifies the reduction in FOG deposit formation when Fly Ash (FA), a Supplementary Cementitious Material (SCM), is used to replace cement in the production of High Volume Fly Ash (HVFA) concrete materials. Results show that after 90 days of leaching test under controlled pH conditions, 75% and 86% reduction in calcium release were achieved from 50% and 75% FA replacement, respectively. After 30 days of FOG deposits formation tests on HVFA samples, 58% and 81% reduction in FOG deposit formation was found for 50% and 75% FA replacement, respectively. FTIR analyses of FOG deposits formed on concrete samples without FA replacement exhibited high calcium soap content (48%), while, FOG deposit formed on HVFA concrete materials showed low calcium soap percentage (22~29%). Furthermore, FTIR analyses report the first spatial variation found in FOG deposits that includes a surface layer of hard FOG deposits with high calcium soap absorbance and an outer layer of soft FOG deposits consisting of a low calcium absorbance. FTIR analyses revealed that the FOG deposit formation mechanism is affected by the availability of calcium and pH near the concrete surface. Finally, HVFA concrete materials were tested for compressive strength and durability against microbially induced concrete corrosion (MICC). After 180 days of sealed curing, HVFA concrete exhibited adequate compressive strength necessary for the sewer line construction and 50% FA replacement revealed satisfactory durability against MICC.

A New Look at the Geological Structure of the Knurów Hard Coal Deposit in Light of Model Tests

Abstract The Knurów hard coal deposit is characterized by rich fold and fault tectonics and diverse morphology of the overburden. The deposit contains a fold zone called Knurów anticline and four complex of faults with the total amplitudes reaching up to several dozen meters. While making a 3D model of the deposit, a range of complications related to the correct interpretation of the running and development of the aforementioned tectonic structures were encountered. Additional data were begun to be introduced during the detailed analysis of the 3D model being made in stages, thereby forcing the software to perform the modeling according to preset assumptions. This process covered such areas of the deposit that were poorly explored or documented to an extent requiring an intervention from a geologist.

Designing multilayer diamond like carbon coatings for improved mechanical properties

New multilayer coatings were produced by incorporating alternating soft and hard DLC layers enabled by varying the bias voltage during deposition process while maintaining a constant hard-to-soft layer thickness ratio. These coatings were deposited onto a Cr/CrCx graded layer by closed field unbalanced magnetron sputtering (CFUBMS). The cross-sectional analysis of the coatings showed that the multilayer coatings possess sharp interfaces between the soft and hard layers with the hard to soft layer thickness ratio (1:1.33) constant in all the coatings. Raman analysis uncovered the increasing sp3 character of the DLC coatings as a result of decreasing ID/IG ratio and increasing full width at half maximum (FWHM) values of the G band peak induced supposedly by an increase in bias voltage during hard layer deposition. Nanoindentation tests showed an increase in hardness of the DLC coatings which can be correlated with the increase in the sp3 content of the coatings as well as decreasing sp2-C cluster size, as calculated from the ID/IG ratio. Furthermore, the coatings exhibited excellent plastic deformation resistance and adhesion strength upon microindentation and scratch testing, respectively. Although further investigations are required to assess coating durability, the multilayer design could offer the DLC coatings with a rare opportunity to combine the high hardness with damage resistance with a constant bilayer thickness and without the need to introduce complex multilayer system.

Evaluation of a systematic digitized training program on the effectivity of subgingival instrumentation with curettes and sonic scalers in vitro

ObjectivesWhereas the key role of subgingival instrumentation in periodontal therapy is well known, the influence of operators’ experience/training with different devices on treatment results is yet uncertain. Therefore, we assessed untrained undergraduate students, working on manikins, as to how effectively they learn to use curettes (GRA) and sonic scalers (AIR); hypothesizing that AIR will result in higher relative cleaning efficacy (RCE) than GRA.Material and methodsBefore baseline evaluation (T0), 30 operators (9 males, 21 females) received a 2-h theoretical lesson for both instruments, followed by a 12-week period with a weekly digitized training program for 45 min. During three sessions (T1–T3), the operators had to instrument six equivalent test teeth with GRA and AIR. At T0–T3, treatment time, proportion of removed simulated biofilm (RCE-b), and hard deposits (RCE-d) were measured.ResultsAt T0, RCE-b was in mean(SD) 64.18(25.74) % for GRA, 62.25(26.69) % for AIR; (p = 0.172) and RCE-d 85.48(12.32) %/ 65.71(15.27) % (p < 0.001). At T3, operators reached highest RCE-b in both groups (GRA/AIR 71.54(23.90) %/71.75(23.05)%; p = 0.864); RCE-d GRA/AIR: 84.68(16.84) %/77.85(13.98) %; p < 0.001). Both groups achieved shorter treatment times after training. At T3, using curettes was faster (GRA/AIR 16.67(3.31) min/19.80(4.52) min; p < 0.001).ConclusionsAfter systematic digitized training, untrained operators were able to clean 70% of the root surfaces with curettes and sonic scalers.Clinical relevanceIt can be concluded that a systematic digitized and interactive training program in manikin heads is helpful in the training of root surface debridement.

Enzymatic removal of dags from livestock: an agricultural application of enzyme technology.

The effective removal of dags (manure balls) from cattle, sheep and goats is a significant issue for the livestock industry. Dags are hard recalcitrant deposits composed of materials, such as faeces, hair, soil, urine, feed and straw, and attach to the animal through the hair rather than the skin. Dags build up during wet periods, especially on long haired breeds, and can weigh up to 40kg per animal for cattle. Dag removal prior to slaughter reduces the risk of microbial meat contamination and damage to the hide during leather processing. Existing removal methods include hair trimming or extensive hose washing that can result in stress to the animal and increased costs. An alternative solution is the application of enzyme formulations that target specific components of the dag so they are more easily removed by washing. Enzymes are already used in other cleaning applications and are proven for the breakdown of materials such as lignocellulose, protein or starch that are found in dags. This mini-review discusses the challenges of current dag removal methods and the state of the art and feasibility of applying enzyme formulations for the effective removal of dags. Although enzyme formulations are yet to be tested in large-scale cattle trials and questions remain regarding how they would be cost-effectively applied to live animals, the results at laboratory scale suggest further research is warranted. Overall, enzymes present an environmentally friendly solution to the high costs and animal welfare issues of current dag removal methods through significant reductions in cleaning time and water use. KEY POINTS: • Dag formation on livestock is a major issue for industry and for animal welfare. • Current methods are costly and challenging for operators and the animal. • Enzymes can degrade dag components to aid release with keratinases showing promise. • Dag removal needs to be field tested, and positive business cases must be generated.

Nanoscale and Macroscale Effects of Mineral Deposition During Water Evaporation on Nanoporous Surfaces

Recent studies have indicated that droplet evaporation heat transfer can be substantially enhanced by fabricating a thin nanoporous superhydrophilic layer on a metal substrate. Such surfaces have immense potential to improve spray cooling processes, however, little durability testing of the surface has been performed. In spray cooling applications, as water evaporates any impurities in the water will be deposited onto the surface. Primarily, this investigation serves to demonstrate how minerals in hard water deposit on the surface and interact with the ZnO nanopillars of the superhydrophilic surface. Quantifying the effects of mineral scale on droplet spreading and vaporization heat transfer on the surface is important in determining implementation requirements to advance the surface into industry applications. Micrographs of the surface demonstrate minerals deposit nonuniformly and quickly fill the nanostructure. Despite a reduction in the extent of droplet spreading due to the mineral deposition, scaled surfaces still demonstrated improved thermal performance compared to an uncoated, smooth copper surface. Scale tended to build up on previously deposited scale, leaving largely uncoated areas where droplets chose to preferentially spread and resulting in a continued low contact angle. Maintaining these uncoated areas and reducing the contaminants present in the water will extend the life and performance of the nanostructured surface.

Primordial odontogenic tumour: A systematic review of the common but also unusual features of this novel entity

BackgroundPrimordial odontogenic tumour (POT) is a novel entity that was described in 2014 and that is included in the group of benign mixed epithelial and mesenchymal odontogenic tumours. In recent years, several papers have added new cases with some clinical and histopathological aspects that slightly differ from those described in the original report. The aim of this systematic review is to update all available data on POT published in the literature and to identify those features of the neoplasm that require further investigation. Materials and methodsA systematic review of literature was conducted using PubMed, Embase, Web of Science and Scopus. Additional sources were also checked. Publications reporting cases with enough clinicopathological information were included, without any time or language restrictions. Histopathological or radiological studies were considered for qualitative analysis. ResultsA total of 30 publications were included. Seventeen papers were used for quantitative analysis while 13 papers were used only for qualitative analysis. A total of 18 cases of POT were identified. Some clinical, radiographic, histopathological and therapeutic features were common in all reported cases, while other aspects of the neoplasm were inconsistent through published cases. This inconsistency was particularly remarkable when dealing with the histopathological features of the neoplasm. DiscussionSome issues about POT remain unclear and deserve to be clarified by future reports. The description of the odontogenic epithelium covering the ectomesenchyme is often contradictory, while it remains debatable whether peripheral ameloblastic epithelial islands or hard dental tissue deposition can occasionally occur within the tumour.

Inline technique to evaluate the performance of scale inhibitors for calcium carbonate scale aggregation and prevention

Calcium carbonate scale is a problem in many industrial and domestic processes, as it precipitates from solution to form a hard deposit which grows on equipment surfaces. The potential for scale formation and aggregation is present whenever a solution becomes supersaturated. Scale formation and prevention creates a considerable capital, operation and maintenance problem. Achieving effective and economical scale control and removal is consequently a major concern for efficient and safe industrial operations. To prevent such potential problems, it is important to understand the mechanism of the calcium carbonate scaling process.This paper is part of the continued effort to understand calcium carbonate formation and mitigation related to oilfield operations. The paper describes the application of a new method, based on laser refraction measurement in transferring the signals to current, to determine the formation of calcium carbonate scale in high calcium brines. This method provides a real-time measurement of the magnitude of scaling crystals, and has been proven to be a sensitive method to monitor the initial stages of the precipitation process. This study focuses on the comparison between two techniques to evaluate formation and aggregation of scale in the presence and absence of scale inhibitors at different temperatures. Also, the efficiency of laser technique will be assessed as an effective tool for the scale and aggregation inhibitors performance and ranking, where the results will be compared with the offline measurement technique using a static test method.

Characterisation and energy assessment of fats, oils and greases (FOG) waste at catchment level

Several of the waste materials that have a negative impact on the sewer system are produced by fats, oils and greases (FOG) discharged from commercial and domestic kitchens. These materials accumulate at different points in the sewer catchment, from kitchens to pumping stations, sewers and sewage treatment works (STWs), and comprise oily wastewater, floating agglomerates and hard deposits. Despite their detrimental effects, these waste materials have a high calorific content and are an ideal feedstock for energy recovery processes. So far, the overall volume of each type of waste and their physical-chemical properties in relation to their collection point are unknown. However, from a management point of view, knowledge on each feedstock quality and volumes is necessary to develop an economic viable solution for their collection and for energy recovery purposes. In this study, FOG wastes collected from households, food service establishments (FSEs), sewage pumping stations, sewers and STWs, were compared to sewage sludge in terms of organic contents and energy potentials. As expected, FOG recovered at source (households and FSEs) were ‘cleaner’ and had a higher energy content. Once mixed with wastewater the materials changed in composition and lost some of their energy per unit mass. Our results showed that around 94,730 tonnes.year−1 of these materials could be recovered from the Thames Water Utilities’ catchment, one of the most populated in the UK. These materials could produce up to 222 GWh.year−1 as biogas, close to double of what is produced with sewage sludge digestion and around 19% of the company energy needs. Finally, even with over six million households in the catchment, the results showed that most of the FOG waste was produced by FSEs (over 48,000 premises) with an estimated average of 79,810 tonnes.year−1 compared to 14,920 tonnes.year−1 from private households. This is an important outcome as recovery from FSEs will be cheaper and easier if the company decides to implement a collection system for energy recovery.

Reconstruction of Lead Acid Battery Negative Electrodes after Hard Sulfation Using Controlled Chelation Chemistry

Lead acid batteries (LABs) remain an inexpensive energy storage technology with a wide application base. However, their short cycle lifetimes necessitate improved recycling and maintenance technologies to combat their various failure modes. One major cause of failure is hard sulfation, where the formation of large PbSO4 crystals on the negative active material impedes electron transfer. Here, we introduce a protocol to remove hard sulfate deposits on the negative electrode while maintaining their electrochemical viability for subsequent electrodeposition into active Pb. Soaking the hard sulfate negative electrode in an alkaline EDTA solution reshaped the surface by solubilizing PbSO4 to Pb-EDTA while avoiding underlying Pb phases. Thereafter, we explored electrodeposition of the Pb-EDTA complex as fresh electrode material and found reduction of Pb-EDTA required lower deposition overpotentials with decreasing pH. We used electrodeposited films on gold to demonstrate cycling of the restored active Pb in H2SO4. The film’s capacity gradually faded with cycling and PbSO4 formation, alike to commercial LABs. Lastly, we demonstrated the electrodeposition of Pb directly onto negative electrodes from a commercial LAB. Our unique approach seeds opportunity for recycling the electrode materials inside LABs without disassembly or extensive material processing.

Comparative clinical evaluation of the therapeutic effects of low-level laser and hyaluronic acid on gingivitis catarrhalis in children

Background/Aim. Gingivitis catarrhalis is the most common disease of the oral mucosa in children, representing an inflammation of the gingiva of an exudative nature. The aim of this study was to evaluate the effectiveness of low-level laser therapy and hyaluronic acid therapy on gingivitis catarrhalis in children using the appropriate clinical parameters. Methods. The study involved 100 children with permanent dentition in whom gingivitis catarrhalis had been diagnosed. The examinees were divided into two groups: the group I consisting of patients with gingival inflammation (50 examinees) in whom the therapy with hyaluronic acid was applied after the removal of soft and hard dental deposits, and the group II consisting of patients with gingival inflammation (50 examinees) in whom low-level laser therapy was applied after the removal of soft and hard dental deposits. Clinical evaluation of the therapeutic effects of low-level laser and hyaluronic acid on gingivitis catarrhalis was performed using the appropriate indices: the Greene-Vermillion Plaque Index (PI), Muhlemann bleeding index (BI), and Community Periodontal Index of Treatment Needs (CPITN). Results. Using the Student?s t-test for dependent samples, a statistically significant difference was obtained (p &lt; 0.001) between the PI, BI, and CPITN indices before and after the therapy in both examined groups. Moreover, the CPITN index after the therapy in the group II was statistically significantly lower (p &lt; 0.05) than that obtained in the group I. Conclusion. The results demonstrated an exceptional effect of hyaluronic acid and low-level laser therapy, supplementing basic therapy, in the treatment of catarrhal gingivitis in children. Somewhat better results were achieved with the combination of basic therapy and low-level laser.

Regenerative Endodontics: A Paradigm Shift in Clinical Endodontics.

ABSTRACTPreserving the natural dentition in its normal form and function is one of the major goals of endodontic treatment. Re-establishing the lost vitality and development of root maturation in immature permanent teeth with pulp necrosis/apical periodontitis is quiet challenging clinically. The very basis of regenerative endodontics relies on the concept of tissue engineering using stem cells, biomimetic scaffold, and bioactive growth factors to regenerate the pulp tissue damaged by microbial infection, injury, or developmental defects. In clinical endodontics, this approach is referred to as a “paradigm shift.” Even though repair instead of true regeneration is achieved with current protocols, it is hoped that further research in the area of stem-cell-based tissue engineering will allow for true regeneration and improved treatment outcomes. The aim of this review is to discuss about the various aspects of regenerative endodontics, current clinical protocols, and the future of pulp regeneration techniques.

Linear discontinuous deformations created on the surface as an effect of underground mining and local geological conditions-case study

Underground mining negatively impacts the rock mass and land surface, as well as the objects located on it. One of the forms of such impact are linear discontinuous deformations, which presently in Polish Upper Silesian Basin conditions are more and more often accompanied by underground mining. Discontinuous deformations of mining origin not always arise on the surface, resulting from the occurrence of unfavorable geological and mining factors, and create different forms, mainly ground steps, cracks, and fissures. Presented in this article results of the research concern the problem of the occurrence of linear discontinuous deformations in the area of the greatest Polish hard coal deposit, Upper Silesian Basin, where several unfavorable factors triggered the system of linear discontinuous deformations in the shape of ground steps. Ground steps caused several damages to building objects, small architecture elements, and roads in surrounding area. One of the most important objects exposed to damage threat here is an old historic church. Ground steps occurred as a joined effect of underground mining influences together with impact of fault zones located close to the church and probably activated by mining works. In the paper, mining and geological conditions have been discussed, that led to arising of discontinuous deformations on the surface. Apart from description of mentioned factors, detailed calculations were carried out aimed at recognition of probable distribution on the surface of subsidence, horizontal displacement, and horizontal strain around the church. Their contribution to ground steps creation process has been discussed as well.

Use of rice straw-based biochar for batch sorption of barium/strontium from saline water: Protection against scale formation in petroleum/desalination industries

The formation of hard mineral scale deposits (e.g., celestite (SrSO4) and barite (BaSO4)) is the most common problem that hinders sustainable operations of water-flooded oilfield and desalination systems (i.e., membrane fouling) when using poor quality water contaminated with barium (Ba(II)) and strontium (Sr(II)) ions. In this work, nanoscale biochar (∼53–712 nm) was synthesized from waste rice straw (cost = 380 to 560 ± 27 US$/Ton; n = 9) and applied as a protective approach against the formation of mineral scale deposits via adsorptive removal of Ba(II)/Sr(II) contaminants from 30,000 ppm saline wastewater. Adsorption of Ba(II)/Sr(II) ions onto biochar was investigated and optimized as a function of biochar amount, water pH, contact time, temperature, and Sr(II)/Ba(II) ratio using response surface methodology. Based on kinetic and isotherm analyses, the biochar exhibited enhanced potential to capture Sr(II)/Ba(II) ions via weak ion-exchange or pore-filling mechanisms (sorption energy (E)≈ 0.61–0.89 kJ/mol). A comparison of partition coefficient (PC) values verified that sorption of Sr(II) onto biochar is far superior to that of Ba(II) (PCs of 10.1 and 2.5 μmol g−1 μM−1, respectively). Sorption selectivity was mainly dependent on solution pH and the metallic properties of Ba(II)/Sr(II)(e.g., metal size, speciation, and mobility). Quantitative analysis of treated saline water using electrical conductivity and ion chromatography confirmed the ability of biochar sorbent to remove Ba(II) and Sr(II) ions (97.5%) with pre-desalination (e.g., total salts reduction of 25.7% after 48 h). It is thus recommended to utilize the prepared biochar as a promising pre-desalinating adsorptive medium to inhibit mineral scale formation before oilfield water flooding in the petroleum field and membrane desalination systems.

Preface to the special issue – Exploration models for New Zealand’s hard rock gold deposits

This special issue comprises a group of nine papers resulting from the 4-year (2014–2018), New Zealand Government-funded, Gold Exploration Models research programme carried out collaboratively by G...

INFLUENCE OF A TURBULENT ENVIRONMENT ON THE MANAGING OF A MINING ENTERPRISE

Motivation: It should be taken into consideration that classical planning methods that worked well at the end of the 20th century are often not effective in a turbulent environment. The article presents planning methods that can be applied in such conditions.&#x0D; Problem statement: The article presents methods of planning of the future in a variable environment. There are constant changes in the macro-environment of mining enterprises in Poland. Therefore, it is extremely difficult to create an appropriate plan for the company's core business i.e. extracting hard coal deposits.&#x0D; Approach and results: The scenario-based planning and SARIMA mathematical model and the forecasts for the demand for hard coal based on them have been presented. The scenarios are used to verify the potential company strategy.&#x0D; Conclusions: It should be noted that the strategy must be created in several variants which finally will enable the company to choose the one that will let it gain a competitive advantage. Only then will the mining company be able to stay ahead of its competitors. In order to allow decision-makers in companies to make the right decisions, appropriate methods and tools for managing the company should be used.

Analysis of clinical manifestations and treatment in 26 children with fibrodysplasia ossificans progressiva in China

Fibrodysplasia ossificans progressiva (FOP) is a rare and disabling heritable connective tissue disease that is difficult to treat. This study seeks to explore the clinical characteristics, clinical manifestations, treatment and prognosis of FOP to provide a clinical basis for its early diagnosis and treatment. Twenty-six children with FOP were retrospectively analyzed in terms of their onset, clinical manifestations, auxiliary examinations and treatment. Among the 26 cases, the youngest age of manifestation of mass was 8days after birth, and the average age was 3years and 2months. The peak age was 2-5years old. Inflammatory mass and toe-finger deformity are the main early clinical manifestations of the disease. These inflammatory masses often lead to hard osteogenic deposits that initially mainly involve the central axis, such as the neck (22/26, 84.6%), back (20/26, 76.9%), and head (13/26, 50%). Toe-finger deformity mainly manifests as symmetrical great toe deformity, or short and deformed thumb and little finger. The diagnosis of FOP requires typical clinical manifestations or ACVR1 gene detection. The main therapeutic drugs for FOP include glucocorticoids and non-steroidal anti-inflammatory drugs. Although not compliant with the recommended medical management of FOP, in our clinical practice children with uncontrollable illness could be treated using a variety of immunosuppressive agents in combination. FOP is a rare autosomal dominant heritable disease. The main clinical manifestations observed in this study were recurrent inflammatory mass and toe-finger deformity. If the diagnosis and treatment are not performed in a timely manner, serious complications are likely to affect the prognosis. Therefore, early diagnosis and active treatment should be performed.

Study of efficacy of intravitreal triamcinolone acetonide (IVTA) for the treatment of refractory diabetic macular edema (DME) in type 2 diabetes mellitus patients

Study of efficacy of intravitreal triamcinolone acetonide (IVTA) for the treatment of refractory diabetic macular edema (DME) in type 2 diabetes mellitus patients - IJCEO- Print ISSN No: - 2395-1443 Online ISSN No:- 2395-1451 Article DOI No:- 10.18231/j.ijceo.2019.097, Indian Journal of Clinical and Experimental Ophtha

Burundi Population Awareness about Gout and the Pivotal Role Played by Physical Exercise in Prevent and Managing Gout Relating Problems

Gout is a type of inflammatory arthritis that may sometimes be called gouty arthritis. Gout develops in some people who have high levels of uric acid in their body and bloodstream, a condition called hyperuricemia. When uric acid builds up in the joints, it can form needle-like crystals. This can cause inflammation and sudden and severe pain, as well as stiffness, tenderness, redness, warmth and swelling. The pain may last hours or weeks and make it difficult to perform daily activities. The build-up of uric acid can look like lumps under the skin, called tophi. It can also collect in the kidneys and cause kidney stones (small, hard deposits).

Nd:YAG lasers in nonsurgical periodontal treatment - a literature review

Nonsurgical periodontal therapy addresses debriding the area of bacteria, endotoxins, and hard deposits from the root surface to restore gingival health.The instrumentation is focused on the root surface and most often accomplished through manual and power scaling. Nowadays lasers can alsobe used for root debridement.