Recycling of mine wastes as raw materials for the construction sector: Solutions based on materials circularity and sustainable resource governance

The mining industry in general, and the phosphate industry in specific is an important mainstream in terms of waste rocks as it generates huge amounts of waste rocks and tailings during their activities. As a matter of example, the phosphate mining in Morocco produces amounts up to 150 million tons or even more of waste rocks and tailings each year. Non-polluting mine wastes (Tailings and waste rock) must be regarded as an opportunity to create new value. The reuse of these wastes, depending on their chemical, mineralogical and geotechnical properties, as alternative raw material in construction and building materials field constitutes a promising environmental solution. The main objective of our studies in Morocco was to investigate the feasibility of using non-polluting mine wastes to produce materials especially for the construction sector, such as using phosphate mine wastes as cementing materials, as additives in mortars or concrete, or as raw materials for bricks, ceramics and geopolymers or aggregates for roads construction and B25 concrete. The phosphate waste rock has to be classified in the category of natural aggregates that are similar to conventional materials. Laboratory and pilot scale investigations demonstrated that recycling mine wastes from may be feasible. The presentation will be focused mainly will be focused mainly on the valorization of phosphate waste rock an alternative aggregate in the construction sector. In addition, Jerada coal mine wastes recycling investigate the use of an integrated and circular approach based on coal recovery and waste rock recycling as alternative clays and aggregates (gravel and sand) in the construction sector. Froth flotation was used to recover coal particles using diesel as a collector and Methyl Isobutyl Carbinol as a frother. The tailings of coal flotation process (CFT) were used to manufacture fired bricks at a pilot scale. Then, gravel and sand obtained after a CMWR screening were tested as alternative materials for concrete production. The choice of the construction sector is based on its capacity to absorb huge quantity of materials

Divergences in the Control of Mitochondrial Respiration Are Associated With Life-Span Variation in Marine Bivalves

The role played by mitochondrial function in the aging process has been a subject of intense debate in the past few decades, as part of the efforts to understand the mechanistic basis of longevity. The mitochondrial oxidative stress theory of aging suggests that a progressive decay of this organelle’s function leads to an exacerbation of oxidative stress, with a deleterious impact on mitochondrial structure and DNA, ultimately promoting aging. Among the traits suspected to be associated with longevity is the variation in the regulation of oxidative phosphorylation, potentially affecting the management of oxidative stress. Longitudinal studies using the framework of metabolic control analysis have shown age-related differences in the flux control of respiration, but this approach has seldom been taken on a comparative scale. Using 4 species of marine bivalves exhibiting a large range of maximum life span (from 28 years to 507 years), we report life-span-related differences in flux control at different steps of the electron transfer system. Increased longevity was characterized by a lower control by NADH (complex I-linked) and Succinate (complex II-linked) pathways, while respiration was strongly controlled by complex IV when compared to shorter-lived species. Complex III exerted strong control over respiration in all species. Furthermore, high longevity was associated with higher citrate synthase activity and lower ATP synthase activity. Relieving the control exerted by the electron entry pathways could be advantageous for reaching higher longevity, leading to increased control by complex IV, the final electron acceptor in the electron transfer system

Beneficial effects of Rhizophagus irregularis and Trichoderma asperellum strain T34 on growth and fusarium wilt in tomato plants

Fusarium tomato wilt is one of the most prevalent and damaging diseases wherever tomatoes are grown intensively. Progress in agriculture in the twenty-first century is set to be based on lowering agrochemical inputs (implementation of Directive 2009/128/EC on sustainable use of pesticides), which can be achieved to some extent through the use of beneficial microorganisms. This study aimed at comparing the effects of the mycorrhizal fungus Rhizophagus irregularis and the biological control agent Trichoderma asperellum strain T34 on the incidence of fusarium wilt and the growth of tomato plants. Both R. irregularis and T34 lowered disease incidence at similar rates, compared to control plants. R. irregularis added below the seedlings reduced disease incidence more than when it was mixed with the substrate. T34 and R. irregularis increased plant height to the same extent, compared to both control and diseased plants. R. irregularis gave the highest levels of chlorophyll, followed by T34 and control plants; however, the measures for infected plants were slightly better for T34 than for R. irregularis. T34 and R. irregularis had similar effects on Ca, Mg, S, Mn, B and Si uptake in tomato plants, but R. irregularis induced a greater P, K, Zn, Cu and Mo accumulation than T34. Interestingly, at the end of the experiment, the depletion of the substrate was lower on Ca, Mg and S for plants inoculated with either R. irregularis or T34 compared to control plants, while the substrate for T34-treated plants had the lowest levels of Fe, Mn, Zn and Cu

A Case of Pemphigus Herpetiformis in a 12-Year-Old Male

Pemphigus herpetiformis (PH) is one of the less common forms of pemphigus. PH in children is unreported. We describe a case of a child who developed PH. Observation. A 12-year-old boy was seen at our department with erosive plaques, vesicles, and crusted cutaneous lesions associated with severe itching persisting for six months. Histologic examination showed an intraepidermal bulla containing rare acantholytic epidermal cells with eosinophilic spongiosis. Direct immunofluorescence demonstrated intercellular Ig G and C3 deposit. The serum titer of antibodies against intercellular epidermal was 1/200 UI/l. Diagnosis of PH was made, and treatment with Dapsone 2 mg/kg per day resulted in total clinical remission. However, two months later, new vesicles reappeared and treatment was begun with prednisone at a dose of 2 mg/kg daily. There was a very good response. Discussion. Childhood pemphigus herpetiformis is a rare disease, often initially misdiagnosed. It must not be forgotten that the disease is a possible cause of erosive mucocutaneous disease in children

Spinal extradural meningioma en plaque with nerve root attachment and extracanal (intrathoracic) extension: Review of literature on management and case report

Meningiomas are relatively common primary spinal tumours, being the second most common intraspinal tumours probably after vertebral haemangioma.It constitutes about 25% of all intraspinal tumours; however, in the presence of extradural spinal lesions, the diagnosis of meningioma is uncommon and often not among the first two considerations. Purely extradural spinal meningioma, especially of the “En plaque” variety, usually simulate malignant disease (metastatic diseases and lymphoma) and may result in inadequate therapy, however, the presence of nerve root attachment is even rarer.Our case report is that of an entirely cervicothoracic extradural en?plaque meningioma (WHO grade 1) with a nerve root attachment (right C7) and intrathoracic extension. We highlighted the issues in diagnosis, operative intervention and long-term follow-up

Resistance of thermally modified ash (Fraxinus excelsior L.) wood under steam pressure against rot fungi, soil-inhabiting micro-organisms and termites

Thermal modification processes have been developed to increase the biological durability and dimensional stability of wood. The aim of this paper was to study the influence of ThermoWood® treatment intensity on improvement of wood decay resistance against soil-inhabiting micro-organisms, brown/white rots and termite exposures. All of the tests were carried out in the laboratory with two different complementary research materials. The main research material consisted of ash (Fraxinus excelsior L.) wood thermally modified at temperatures of 170, 200, 215 and 228 °C. The reference materials were untreated ash and beech wood for decay resistance tests, untreated ash wood for soil bed tests and untreated ash, beech and pine wood for termite resistance tests. An agar block test was used to determine the resistance to two brown-rot and two white-rot fungi according to CEN/TS 15083-1 directives. Durability against soil-inhabiting micro-organisms was determined following the CEN/TS 15083-2 directives, by measuring the weight loss, modulus of elasticity (MOE) and modulus of rupture (MOR) after incubation periods of 24, 32 and 90 weeks. Finally, Reticulitermes santonensis species was used for determining the termite attack resistance by non-choice screening tests, with a size sample adjustment according to EN 117 standard directives on control samples and on samples which have previously been exposed to soil bed test. Thermal modification increased the biological durability of all samples. However, high thermal modification temperature above 215 °C, represented by a wood mass loss (ML%) due to thermal degradation of 20%, was needed to reach resistance against decay comparable with the durability classes of ‘‘durable’’ or ‘‘very durable’’ in the soil bed test. The brown-rot and white-rot tests gave slightly better durability classes than the soil bed test. Whatever the heat treatment conditions are, thermally modified ash wood was not efficient against termite attack neither before nor after soft rot degradation