The characterization and effects of stoichiometric reductants in ferrochromium production from 1200oC to 1550oC

Abstract: Ferrochrome alloy is mainly produced in submerged-arc furnaces. The reductants used in ferrochrome production include coke, anthracite and char. During ferrochrome production reductants are primarily added for reduction to take place. However it is still questionable as to what happens during times when the carbon charged is not enough, is stoichiometric or excess than the required amount. This work investigated phase formation and phase changes at different reducing temperatures with stoichiometric amount of reductants with stoichiometric amount of reductant. Experiments were conducted at 1200oC, 1300oC and 1550oC. Anthracite and coke were used in this investigation. A comparison of reaction steps, the extent of reactions as well as the mechanisms at the same temperature and soaking time, when coke and anthracite were used are discussed. The characterization was conducted using different analytical techniques to identify the changes in morphologies of the raw materials against the temperature as well as the phases that formed

Biomass reduction of manganese ore in the presence of carbon monoxide

Abstract: The ferromanganese industry is currently strained by the cost of production that is continuously increasing. Alternatives of reductants are being sought to try and alleviate the production costs namely solar energy, wind and biomass. Some studies on the possible use of biomass using the South African manganese ores were conducted and as preliminary results were generated. The South African manganese industry has focused more on the pre-reduction. The current paper focuses on the use of raw macadamia nut shells for the reduction of manganese ore in the presence of carbon monoxide. The feed and products were characterized using XRD, XRF as well as SEM and compared to products currently obtained using conventional reductants. The basicity of the feed was kept at around 1. The temperature was set at 1450oC, a graphite crucible placed in a silica crucible to prevent any spillages. Comparisons between products obtained when raw macadamia nut shells and conventional reductants were used was done. It was found that macadamia nut shells have great potentials of replacing the conventional reductants used so far. The separation of slag from the metal needs imporvement as the slag structure was more needle-like and some metal entrapments were noticeable as compared to conventional process

高島教授の景気政策 : 『租税・公債・通貨新論』

新刊批

COMMERCIALISATION DES COSSETTES DE MANIOC AMENEES PAR LES CYCLISTES A KISANGANI

The purpose of this article on the marketing of cassava chips brought by the cyclists to Kisangani is to analyze the marketing of cassava chips by the producers them - selves as well as the retailers in Kisangani.  The starting question is to know if the producers of cassava come to sell them - selves their product on the market of Kisangani. Thus, we can ask these questions: -          This movement would it be beneficial for them? -          Would they gain by selling their cassava in Kisangani to supply themselves with various products of first need? -          Would their factors of production be well remunerated?   The assumptions hereafter were formulated, in regard to the interrogations raised above. From our opinion, we consider that this operation would not be economically advantageous for the "Tolekistes" or cyclists salesmen because they often ignore the elements concerned in the calculation of sell price (their deprivations and sacrifices). In order to check these assumptions, a survey questionnaire and a direct observation near the producers and retailers enabled us to achieve the goals of the departure. After examination and processing the data collected, the principal results which come out from this study are as follows: -          This operation is not financially advantageous to the cyclist's retailers. This is due to the fact that they often ignore the elements to be considered in the calculation of the cost price (their deprivations and sacrifices). Thus their profit margin is really a loss as a whole i.e. less than 52 000 FC (see table n°V). -          While for the farmers, this movement can be regarded as relatively beneficial because if a peasant intends to buy an English Wax part on the level of his surveyed village, he must engage 2,3 baskets of cassava chips whereas on the level of Kisangani, he loses only 1,3 baskets of cassava chips that is  practically half (see table VII).  In the light of the results obtained, it arises that the starting assumption was confirmed; this operation is thus not advantageous the "Tolékistes" or to cyclists salesmen in terms of income

Key factors predicting suspected severe malaria case management and health outcomes: an operational study in the Democratic Republic of the Congo

BACKGROUND: Evidence suggests that pre-referral Rectal Artesunate (RAS) can be a life-saving intervention for severe malaria in remote settings in Africa. Recognition of danger signs indicative of severe malaria is critical for prompt and appropriate case management. METHODS: This was an observational study conducted in three Health Zones of the Democratic Republic of the Congo to determine the distribution of dangers signs for severe malaria and assess their impact on RAS use, referral completion, injectable treatment and ACT provision, and health outcomes including death. An individual-level analysis was carried out, using multilevel-mixed effects logistic regression models. Severely ill febrile children < 5 years seeking care from community-based healthcare providers were recruited into a patient surveillance system based on the presence of key danger signs. Clinical and case management data were collected comprehensively over a 28 days period. Treatment seeking was elicited and health outcomes assessed during 28 days home visits. RESULTS: Overall, 66.4% of patients had iCCM general danger signs. Age of 2-5 years and iCCM general danger signs predicted RAS use (aOR = 2.77, 95% CI 2.04-3.77). RAS administration positively affected referral completion (aOR = 0.63, 95% CI 0.44-0.92). After RAS rollout, 161 children died (case fatality ratio: 7.1%, 95% CI 6.1-8.2). RAS improved the health status of the children on Day 28 (aOR = 0.64, 95% CI 0.45-0.92) and there was a non-significant trend that mortality was higher in children not receiving RAS (aOR = 1.50, 95% CI 0.86-2.60). Full severe malaria treatment at the RHF including injectable anti-malarial and a course of ACT was highly protective against death (aOR = 0.26, 95% CI 0.09-0.79). CONCLUSIONS: The main findings point towards the fact that danger signs are reasonably well recognized by health provider at the primary care level, and that RAS could influence positively health outcomes of such severe disease episodes and death. Its effectiveness is hampered by the insufficient quality of care at RHF, especially the provision of a full course of ACT following parenteral treatment. These are simple but important findings that requires urgent action by the health system planners and implementers

Acceptability of pre-referral rectal artesunate for severe malaria in children under 5 years by health workers and caregivers in the Democratic Republic of the Congo, Nigeria and Uganda

BACKGROUND: For children below 6 years with suspected severe malaria attending a health care provider unable to provide parenteral malaria treatment, pre-referral rectal artesunate (RAS) is recommended by the World Health Organization to prevent death and disability. A number of African countries are in the process of rolling out quality-assured RAS for pre-referral treatment of severe malaria at community-level. The success of RAS depends, among other factors, on the acceptability of RAS in the communities where it is being rolled-out. Yet to date, there is limited literature on RAS acceptability. This study aimed to determine the acceptability of RAS by health care providers and child caregivers in communities where quality assured RAS was rolled out. This study was nested within the comprehensive multi-country observational research project Community Access to Rectal Artesunate for Malaria (CARAMAL), implemented in the Democratic Republic of the Congo (DRC), Nigeria, and Uganda between 2018 and 2020. Data from three different sources were analysed to understand RAS acceptability: interviews with health workers during three health care provider surveys (N = 341 community health workers and 467 primary health facility workers), with caregivers of children < 5 years of age during three household surveys (N = 9332 caregivers), and with caregivers of children < 5 years of age who were treated with RAS and enrolled in the CARAMAL Patient Surveillance System (N = 3645 caregivers). RESULTS: RAS acceptability was high among all interviewed stakeholders in the three countries. After the roll-out of RAS, 97-100% heath care providers in DRC, 98-100% in Nigeria and 93-100% in Uganda considered RAS as very good or good. Majority of caregivers whose children had received RAS for pre-referral management of severe malaria indicated that they would want to get the medication again, if their child had the same illness (99.8% of caregivers in DRC, 100% in Nigeria and 99.9% in Uganda). In three household surveys, 67-80% of caregivers whose children had not previously received RAS considered the medication as useful. CONCLUSION: RAS was well accepted by health workers and child caregivers in DRC, Nigeria and Uganda. Acceptability is unlikely to be an obstacle to the large-scale roll-out of RAS in the studied settings

Effectiveness of rectal artesunate as pre-referral treatment for severe malaria in children under 5 years of age: a multi-country observational study

BACKGROUND: To prevent child deaths from severe malaria, early parenteral treatment is essential. Yet, in remote rural areas, accessing facilities offering parenteral antimalarials may be difficult. A randomised controlled trial found pre-referral treatment with rectal artesunate (RAS) to reduce deaths and disability in children who arrived at a referral facility with delay. This study examined the effectiveness of pre-referral RAS treatment implemented through routine procedures of established community-based health care systems. METHODS: An observational study accompanied the roll-out of RAS in the Democratic Republic of the Congo (DRC), Nigeria and Uganda. Children <5 years of age presenting to a community-based health provider with a positive malaria test and signs of severe malaria were enrolled and followed up during admission and after 28 days to assess their health status and treatment history. The primary outcome was death; covariates of interest included RAS use, referral completion, and post-referral treatment. RESULTS: Post-roll-out, RAS was administered to 88% of patients in DRC, 52% in Nigeria, and 70% in Uganda. The overall case fatality rate (CFR) was 6.7% (135/2011) in DRC, 11.7% (69/589) in Nigeria, and 0.5% (19/3686) in Uganda; 13.8% (865/6286) of patients were sick on day 28. The CFR was higher after RAS roll-out in Nigeria (16.1 vs. 4.2%) and stable in DRC (6.7 vs. 6.6%) and Uganda (0.7 vs. 0.3%). In DRC and Nigeria, children receiving RAS were more likely to die than those not receiving RAS (aOR=3.06, 95% CI 1.35-6.92 and aOR=2.16, 95% CI 1.11-4.21, respectively). Only in Uganda, RAS users were less likely to be dead or sick at follow-up (aOR=0.60, 95% CI 0.45-0.79). Post-referral parenteral antimalarials plus oral artemisinin-based combination therapy (ACT), a proxy for appropriate post-referral treatment, was protective. However, in referral health facilities, ACT was not consistently administered after parenteral treatment (DRC 68.4%, Nigeria 0%, Uganda 70.9%). CONCLUSIONS: Implemented at scale to the recommended target group, pre-referral RAS had no beneficial effect on child survival in three highly malaria-endemic settings. RAS is unlikely to reduce malaria deaths unless health system issues such as referral and quality of care at all levels are addressed. TRIAL REGISTRATION: The study is registered on ClinicalTrials.gov : NCT03568344

Germination capacity and seed storage behaviour of threatened metallophytes from the Katanga copper belt (D.R. Congo): Implications for ex situ conservation

peer reviewedBackground and aims - Plant species adapted to metalliferous soil are of high conservation value, and actions for preserving these species (some of them are endemics) are urgent given the threat of mining activities. In the framework of an integrated conservation programme of cuprophytes (plants that tolerate a soil with a high level of copper) in Katanga (D.R.Congo), this study aims at: (1) providing new data on species whose germination has never been studied so far; (2) gaining new insight into the storage behaviour of these species; (3) discussing implications for ex situ conservation of these highly threatened species. Methods - Germination tests were conducted on fresh seeds of nineteen species. These tests were repeated after 6, 12 and 24 months of storage in dry-cold conditions. Key results - Most species kept or increased their germination capacity after 2 years storage in dry-cold conditions. Nine species showed a slight decrease in their viability (from 100% to > 80%) after 2 years storage in dry-cold conditions. The present study gives evidence that at least six of the 19 studied species are desiccation-tolerant (orthodox). Among these, two are strict endemics, Haumaniastrum robertii and Faroa malaissei, and two are broad endemics, Diplolophium marthozianum and Gladiolus robiliartianus. This means that ex situ seed banking of these species could form a useful part of a more comprehensive conservation strategy. Only two species have been identifed as desiccation-sensitive (recalcitrant), i.e. inappropriate for conservation in standard seed bank conditions. An orthodox behaviour has not been ruled out for the other species tested, but their response was less clear and needs further investigation. © 2013 National Botanic Garden of Belgium and Royal Botanical Society of Belgium

Community access to rectal artesunate for malaria (CARAMAL): a large-scale observational implementation study in the Democratic Republic of the Congo, Nigeria and Uganda

The key to reducing malaria deaths in highly endemic areas is prompt access to quality case management. Given that many severe cases occur at peripheral level, rectal artesunate (RAS) in the form of suppositories was developed in the 1990s, allowing for rapid initiation of life-saving antimalarial treatment before referral to a health facility with full case management capabilities. One randomized controlled trial published in 2009 showed a protective effect of RAS pre-referral treatment against overall mortality of 26%, but with significant differences according to study sites and length of referral. Two important issues remained unaddressed: (1) whether the mortality impact of RAS observed under controlled trial conditions could be replicated under real-world circumstances; and (2) clear operational guidance for the wide-scale implementation of RAS, including essential health system determinants for optimal impact. From 2018 to 2020, the Community Access to Rectal Artesunate for Malaria (CARAMAL) project was conducted as a large-scale observational implementation study in the Democratic Republic of the Congo (DRC), Nigeria, and Uganda (registered on ClinicalTrials.gov as NCT03568344). CARAMAL aimed to provide high-quality field evidence on the two issues above, in three remote settings with high malaria endemicity. A number of complementary study components were implemented. The core of the CARAMAL study was the Patient Surveillance System (PSS), which allowed tracking of cases of severe febrile illness from first contact at the periphery to a referral health facility, and then on to a Day 28 visit at the home of the patient. Community and provider cross-sectional surveys complemented the PSS. Here we describe in some detail RAS implementation, as well as the key CARAMAL study components and basic implementation experience. This manuscript does not intend to present key study results, but provides an extensive reference document for the companion papers describing the impact, referral process, post-referral treatment and costing of the RAS intervention