Ash removal from low rank coal

The work presented here is concerned with cleaning of low rank coals such as Texas lignite. As a result, Jewett Texas lignite was cleaned from 28% ash by weight to 8.5%. In the first part of the thesis, it is proved that conventional cleaning techniques used for bituminous and sub-bituminous having pyritic impurities does not work for cleaning lignite coal because of different coal chemistry and the presence of clay impurities. Hence after trying conventional processes, there was a need for a new technique capable of removing clay from low rank coals.;Micronized coal, obtained from DevourX LLC, proved to be more easily separated than run of mine coal, using a slurry-based technique with an agglomerant to isolate carbon rich particles and a lignin based surfactant. The coal was cleaned from 28% ash to 9.5 % ash.;This project was sponsored by the Defense Advanced Research Project Agency (DARPA), under subcontract from the University of Texas at Arlington

Development of low-carbon recycled aggregate concrete using carbonation treatment and alccofine

Since the construction industry is one of the major sectors responsible for the overexploitation of natural resources and the production of greenhouse gases, there is an urgent need to adopt a sustainable and environmental friendly approach to mitigate climate degradation. Research has explored the potential of recycled aggregate (RA) as a viable alternative to natural aggregate in concrete production. Currently, several treatment methods are being employed to enhance the efficient incorporation of RA into concrete, aiming to address this issue. However, the effective utilization of RA in place of NA remains uncommon. In this study, an effort has been made to develop a low-carbon recycled aggregate concrete by utilizing 100% carbonation treated recycled coarse concrete aggregate (CRCCA) in place of natural coarse aggregate (NCA) and alccofine as mineral admixture. A comprehensive analysis was performed, comparing the properties of CRCCA to those of untreated recycled coarse concrete aggregate. This analysis covered changes in weight, bulk density, water absorption, crushing value, and microstructure. Furthermore, five different concrete mixes were prepared, each varying in the proportion of natural coarse aggregate (NCA), untreated RCCA, and CRCCA. These mixes also incorporated alccofine as a mineral admixture. The evaluation process involved assessing the effectiveness of carbonation treatment and alccofine addition through tests on the workability, water absorption, density, and compressive strength of the concrete mixes. The study demonstrated that carbonation treatment of RCCA resulted in substantial improvements in crushing value and water absorption of CRCCA, alongside enhanced workability, reduced water absorption, and increased density in CRCCA concrete. Moreover, CRCCA concrete exhibited notable compressive strength gains at both 28 and 90 days compared to untreated RCCA concrete. Furthermore, the use of CRCCA and alccofine contributed to reducing GHG emissions associated with cement production, emphasizing the environmentally friendly attributes of this low-carbon concrete formulation

Clinical outcomes in management of dislocation of carpometacarpal joints of hand: a rare orthopaedic presentation

Background: Dislocation of carpo-metacarpal (CMC) joints especially involving the 2nd and 3rd or paired dislocations, presents a rare pattern of orthopaedics hand injuries. They are associated with high energy trauma usually involving motorbike accidents. Severe soft tissue inflammation over the affected hand and associated injuries often makes detection of these fractures difficult. They require prompt management at presentation. Failure to be diagnosed and treated at early stage leads to joint stiffness, restrictions of wrist movement, deformity and sometimes ruptures of tendons crossing the wrist. Most of them require open reduction and internal fixation for stabilization. The objective of the study was to clinically evaluate outcomes in management of carpometacarpal joint dislocations.Methods: We prospectively studied 6 cases of CMC dislocation presenting at average of 1week from the original injury. All were clinically and radiologically evaluated. 3 cases were managed with open reduction and internal fixation with K wire and 1with closed manipulation and percutaneous k wire fixation and 1 case by arthrodesis of CMC joint. Functional assessment was done with Quick DASH score at 6 weeks, 3 months, 6 months and 1 year.Results: All the patients went on to have good functional recovery. The average quick DASH score showed improvement from 77.39 to 4.07 over 1 year follow-up. Conclusions: Careful and meticulous examinations of hands are necessary in high velocity trauma cases to avoid missing diagnosis of CMC dislocation. ORIF remains the gold standard treatment which can also be used for cases presenting late, followed by aggressive post-op physiotherapy can lead to excellent recovery of hand function

Clinical outcomes in management of unstable distal radius fractures treated with external fixation and internal fixation: a prospective comparative study

Background: Management of Distal Radius fracture that are inherently unstable is still a matter of debate. There is no conclusive evidence that support one surgical fixation method over another. An attempt was made to analyze patients treated with Ex-Fix and Internal-Fixation for unstable distal radius fractures and evaluate the clinical efficacy of Ex-fix using principles of ligamentotaxis and Internal-fixation and compare functional recovery, fracture healing time and complications.Methods: A prospective trial was undertaken at our hospital with 35 patients,all aged >20 yrs with closed distal radius fracture and divided into two groups: group I (Ex-fix with or without percutaneous k-wire, and JESS) and group II (Int-Fixation) including 14 and 21 patients, respectively. Periodic clinical examination and x-ray review was carried out to find out fracture union, and functional assessment. Patients were followed up for 1 year, 6 months average.Results: Group I consumed significant less operative time, fluoroscopic exposure, reduced hospital stay, quicker post-operative pain relief. Quick DASH score were significantly high in elderly treated with Ex-Fix in comparison to young in which DASH score was higher with internal-fixator. Functional recovery was early with int-fixation but post-operative wrist stiffness was also higher. 2 cases of delayed wound healing &1 case of pin tract infection with ex-fix application was observed. Conclusions: Internal-fixation remains the treatment of choice for unstable distal radius fracture involving the articular surface and in the young, while ext-fixation can be considered as a primary treatment modality in the extra-articular fractures in young or even intra-articular fractures in the elderly

Durability of ternary blended concrete incorporating rice husk ash and calcined clay

Research on the combined substitution of supplementary cementitious materials (SCMs) has already demonstrated that it might be one of the few viable options to produce low-carbon concrete at scale. This paper presents an experimental investigation on the performance and durability of rice husk ash (RHA) and calcined clay (CC) in ternary blended concrete exposed to chloride attacks under wet/dry cycles. Portland cement (PC) was replaced by RHA and CC up to 50% by weight to produce low-carbon concrete. Samples were subjected to wet/dry cycles in 3.5% NaCl water, with mineralogical composition and microstructure development before and after exposure analysed by TGA-DSC, MIP, XRD, and SEM. The durability of the concrete against wet/dry cycles was investigated in terms of compressive strength, water absorption, open porosity, density, thermal conductivity, and electrical resistivity. The results showed that concrete mixes with CC and RHA up to 60% exhibited an increase of 33% in compressive strength, followed by minimal changes in water absorption. While a decrease in electrical resistivity was measured in all samples with RHA and CC, increasing the CC content to 50% resulted in improved resistance to chloride penetration. Increasing the CC content resulted in a more refined microstructure, with an overall decrease in porosity of up to 32% compared to the control series. While RHA alone did not contribute to significant improvements after wet/dry cycles, the combined substitution of RHA and CC at SCM replacement levels of 60% showed an overall improvement in hardened properties and durability. This investigation provides valuable insights into the long-term performance and strength of innovative low-carbon concrete

Origin and spread of human mitochondrial DNA haplogroup U7

Human mitochondrial DNA haplogroup U is among the initial maternal founders in Southwest Asia and Europe and one that best indicates matrilineal genetic continuity between late Pleistocene hunter-gatherer groups and present-day populations of Europe. While most haplogroup U subclades are older than 30 thousand years, the comparatively recent coalescence time of the extant variation of haplogroup U7 (~16–19 thousand years ago) suggests that its current distribution is the consequence of more recent dispersal events, despite its wide geographical range across Europe, the Near East and South Asia. Here we report 267 new U7 mitogenomes that – analysed alongside 100 published ones – enable us to discern at least two distinct temporal phases of dispersal, both of which most likely emanated from the Near East. The earlier one began prior to the Holocene (~11.5 thousand years ago) towards South Asia, while the later dispersal took place more recently towards Mediterranean Europe during the Neolithic (~8 thousand years ago). These findings imply that the carriers of haplogroup U7 spread to South Asia and Europe before the suggested Bronze Age expansion of Indo-European languages from the Pontic-Caspian Steppe region

Synthesis, Characterization and Preliminary Antifungal Activity of Some Co(II) and Zn(II) Complexes Derived from Oximes of 2-Acetyl Aromatic Heterocycles

Present work focuses on syntheses, characterization, preliminary antifungal screening of some transition metal complexes derived from oximes of 2-acetylpyridine, 2-acetylthiophene and 2-acetylfuran; using Zn(II) and Co(II) chlorides. These newly synthesized complexes have been analyzed, characterized and compared with parent ligands on the basis of spectral techniques such as 1H-NMR, 13C-NMR IR and elemental analysis. The antifungal screening performed on derived complexes proved that they show appreciable activity against Candida albicans. DOI: http://dx.doi.org/10.17807/orbital.v13i1.1600 </p

The Interface of Competition law and blockchain Technology: a global Perspective

The rule of law does not govern all human interactions. There are times when the state bypasses legal constraints, as documented by the World Justice Project. Other times, jurisdictions may be mutually unfriendly and refuse to enforce foreign laws. Blockchains create trust between contracting parties at the individual level, enabling them to transact freely and increase consumer welfare. Blockchains can only supple-ment antitrust if the legal constraints do not impede their development. The law should thus support the decentralization of blockchains so that blockchain-based mechanisms may take over (even if imperfectly) where the law does not apply. With that in mind, we justify the attractiveness of that approach by showing that blockchain causes an increase in the number of transactions by creating trust (Part 1), and that it may overall increase the decentralization of economic transactions (Part 2). The law should take into account where it applies (Part 3). We conclude afterward (Part 4)