Economic Constrains Research Articles

Closed-loop process for Zn and Cu selective recovery from MSWI bottom ash fine fraction

In 2019, 224 Mt of Municipal Solid Wastes (MSW) were produced in Europe. A significant proportion of this MSW is treated by incineration producing each year 20 Mt of Municipal Solid Waste Incineration (MSWI) Bottom Ashes (BA). While the coarsest fraction (>2mm) can be reemployed in construction field, this is not the case for the finest fraction <2 mm (30% wt.) which is intended to be landfilled. The challenges of the treatment of this solid residue are multiple. The metals of interest are dispersed within this complex matrix and the gangue is composed by a large proportion of carbonate based minerals which reduces the choice of possible leaching agents. Moreover, the large amounts of iron and aluminum imply to choose a highly selective recovery method and the economic constrains steer the process towards low-cost technologies. The aim of this work is to study the feasibility of a selective copper and zinc recovery, whose contents in the bottom ash fine fraction are comparable to low-grade ores. A four-step process was designed consisting of a flushing, a leaching, a precipitation and an electrowinning. A selective leaching step using ammonia-ammonium chloride solution was carried out to avoid an iron co-leaching. After the leaching step, the precipitation of zinc was achieved by addition of aluminum nitrate followed by an electrodeposition of copper from ammonia medium. Up to 70% of Cu and Zn could be recovered with minimal modifications of the leachate composition allowing thus its reuse. The developed process enables the recovery of metallic copper and zinc in a spinel form from a waste originally intended for landfilling.

Convergence of mechanistic modeling and artificial intelligence in hydrologic science and engineering

Hydrology is a mature physical science based on application of first principles. However, the water system is complex and its study requires analysis of increasingly large data available from conventional and novel remote sensing and IoT sensor technologies. New data-driven approaches like Artificial Intelligence (AI) and Machine Learning (ML) are attracting much “hype” despite their apparent limitations (transparency, interpretability, ethics). Some AI/ML applications lack in addressing explicitly important hydrological questions, focusing mainly on “black-box” prediction without providing mechanistic insights. We present a typology of four main types of hydrological problems based on their dominant space and time scales, review their current tools and challenges, and identify important opportunities for AI/ML in hydrology around three main topics: data management, insights and knowledge extraction, and modelling structure. Instead of just for prediction, we propose that AI/ML can be a powerful inductive and exploratory dimension-reduction tool within the rich hydrological toolchest to support the development of new theories that address standing gaps in changing hydrological systems. AI/ML can incorporate other forms of structured and non-structured data and traditional knowledge typically not considered in process-based models. This can help us further advance process-based understanding, forecasting and management of hydrological systems, particularly at larger integrated system scales with big models. We call for reimagining the original definition of AI in hydrology to incorporate not only today’s main focus on learning, but on decision analytics and action rules, and on development of autonomous machines in a continuous cycle of learning and refinement in the context of strong ethical, legal, social, and economic constrains. For this, transdisciplinary communities of knowledge and practice will need to be forged with strong investment from the public sector and private engagement to protect water as a common good under accelerated demand and environmental change.

Strengthening cancer control in the South Pacific through coalition-building: a co-design framework

Cancer is a significant problem for the South Pacific region due to a range of complex health challenges. Currently gaps in diagnosis, treatment and palliative care are significant, and while governmental commitment is strong, economic constrains limit health system strengthening. Alliances have been successful in strengthening non-communicable disease and cancer control policy and services in resource constrained settings. A regional coalition approach has therefore been recommended as an effective solution to addressing many of the challenges for cancer control in the South Pacific. However, evidence regarding the effective mechanisms for development of alliances or coalitions is scarce. This study aimed to 1) create a Coalition Development Framework; 2) assess the use of the Framework in practice to co-design a South Pacific Coalition. Creation of the Coalition Development Framework commenced with a scoping review and content analysis of existing literature. Synthesis of key elements formed an evidence-informed step-by-step guide for coalition-building. Application of the Framework comprised consultation and iterative discussions with key South Pacific cancer control stakeholders in Fiji, New Caledonia, Papua New Guinea, Samoa and Tonga. Concurrent evaluation of the Framework utilising Theory of Change (ToC) and qualitative analysis of stakeholder consultations was undertaken. The finalised Coalition Development Framework comprised four phases with associated actions and deliverables: engagement, discovery, unification, action and monitoring. Application of the Framework in the South Pacific identified overwhelming support for a Cancer Control Coalition through 35 stakeholder consultations. Framework phases enabled stakeholders to confirm coalition design and purpose, strategic imperatives, structure, local foundations, barriers and facilitators, and priorities for action. ToC and thematic consultation analysis confirmed the Framework to be an effective mechanism to drive engagement, unification and action in alliance-building. A Coalition to drive cancer control has significant support among key Pacific stakeholders, and establishment can now be commenced. Importantly results confirm the effective application of the Coalition Development Framework in an applied setting. If momentum is continued, and a regional South Pacific Coalition established, the benefits in reducing the burden of cancer within the region will be substantial. This work was completed for a Masters of Public Health project. Cancer Council Australia provided project funding.

Primary hyperoxaluria type 1 in developing countries: novel challenges in a new therapeutic era.

ABSTRACTPrimary hyperoxaluria type 1 (PH1) is an autosomal recessive inborn error of metabolism characterized by marked hepatic overproduction of oxalate due to deficiency of hepatic peroxisomal alanine-glyoxylate aminotransferase caused by AGXT gene mutation. One major hallmark of PH1 in developed as well as developing countries (DC) is the diagnostic delay. Notably in DC, where the disease is most prevalent and probably underdiagnosed, there are many challenges in PH1 diagnosis and management, with economic constrains and ethical concerns. This has led to the existing gap in the management of PH1 between developed and DC, which is expected to further deepen with the advent of novel therapeutic agents unless appropriate actions are taken. Until recently, treatment possibilities were limited to supportive measures. Thanks to a better understanding of the molecular basis of the disease a number of new therapies are developed, or being developed, leading to profound changes in management strategies. In this review we discuss the current situation of PH1 in DC as well as the accessibility challenges and the advantages of using promising novel therapeutics to bridge the currently existing gap. We also provide an overview of an integrated approach to ensure equitable access of sustainable therapeutics to PH1 patients in DC. This is expected to reduce global PH1 healthcare disparities, improve its standard of care and reduce disability linked to extrarenal complications of PH1 by implementing personalized medicine.

Impact of rituximab in Mexican patients with Multiple Sclerosis–A single-center retrospective study

BackgroundMultiple Sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS). B cells have an essential role in the disease pathogenesis and therefore selective B-cell depletion are commonly used to treat the disease. Rituximab (RTX), a chimeric anti-CD20 monoclonal antibody had demonstrated reduced inflammatory activity and radiological activity in MS patients. Due to economic constrains and treatment access limitations, RTX is often used as a treatment alternative in these patients. Here, we described our center experience in RTX -treated MS patients. MethodsA single-center observational retrospective study was conducted in a Mexican cohort MS during 2010 to 2020. All patients had a confirmed MS diagnosis.All patients received fixed scheme involving induction with 1 g on day one and day 15, followed by 500 mg-1 g every six months for maintenance. Annual Relapse Rate (ARR), Progression index (PI), Expanded Disability Status Scale (EDSS) and MRI activity of the disease were evaluated. Comparison between naïve and non-naïve patients was also conducted. ResultsA total of 85 patients were included. The mean age at diagnosis was 33.13 (±8.90) years with 73 (85.9%) being RRMS. 39 (34.1%) were treatment-naïve. While treated with RTX, 62(72.9%) patients reached a free-of-relapse status, with statistically significant decrease in the mean ARR from 0.82 to 0.36 [0.14 (95%CI: 0.09–0.20), p = 0.0001 and EDSS [0.25 CI 0–0.5 (p = 0.034)] and a decrease in their T1 Gd-enhancing MRI lesions (1.64 vs. 0.12 CI 0.70–2.30, p = 0.004. 29 (29.4%) patients achieved NEDA-3. Among all patients, only 2 (2.4%) experienced infusion-related mild adverse events. No serious adverse events were reported. ConclusionWe found significant clinical and radiological improvement in naïve and non-naïve MS patients treated with RTX.

Etiological classification and clinical spectrum of Egyptian pediatric patients with disorder of sex development, single center experience

The aim of the current work was to review the clinical profile, aetiological classification, as well as the management of Egyptian paediatric patients with disorders of sex development (DSD) presenting at a tertiary centre in Cairo. The study was a cross-sectional observational study that included Egyptian patients who attended the Endocrinology clinic during a period of one year from January to December 2019. All patients with overt genital ambiguity aged from 0 to 18 years were recruited in the study. Diagnosis of DSD was based on clinical features and hormonal profile. Out of 100 patients, 71% had 46XY DSD, 24% had 46XX DSD, while sex chromosome DSD was identified in 5%. The median age of presentation was 12 months with 19% presented during infancy. The most common cause of 46XY DSD was due to either defect in androgen synthesis or action (40%) with the majority due to androgen insensitivity syndrome (28%). Most of the 46XX DSD (21/24) patients were diagnosed as classic congenital adrenal hyperplasia secondary to deficiency of 21 hydroxylase enzyme, with 90% being salt wasters. Our series revealed that 46XY DSD was the most frequent DSD aetiological diagnosis, with androgen insensitivity syndrome representing the commonest cause. CAH with classic salt wasting type was the second most common disorder. Management of children with DSD is challenging especially with lack of adequate resources. The crucial issues that stand against proper diagnosis and management are late presentation combined with economic constrains, and social and cultural issues.

The Impact of Working from Home Induced by Covid 19 On Working Women in Harare, Zimbabwe

Working from home (WFH) can be a challenge as well especially in third world countries due to economic constrains as some people cannot afford gadgets and internet. Women are not spared as well as they are involved in multi-task. Drawing from employee isolation literature, this paper aimed to examine the impact of working from home on female employees during the imposed lockdown. Qualitative research was employed and in-depth interviews with 25 working women from different professions were conducted to gather data. Purposive and convenient sampling was used to select 25 working women from different professions and data was analyzed using MAXQDA software. The research finds out that, women are working overtime due their gender roles as caregiver and the fact that they are mothers, daughters, aunt, sisters, and daughter in-laws they end up involving in multi-task since they are at home, they find it is difficult to convince people that they are working since they will be at home and they cannot ignore visitors during working hours since women are known for their hospitality role in the family hence resulting in mental exhaustion. The study recommended more studies to be carried out on the impact of working from home to assist policy makers on the way forward during Covid 19 era.

Power and sovereignty

How do nation states relate to each other in terms of power? How do they relate to private parties in terms of power? Nation states are often thought of as sovereign to tax. In a legal sense that may be true. However, to be legally sovereign is not the same thing as being able to effectively exercise sovereignty. The mobility of capital and businesses, or at least the perception of their mobility, is increasingly pressuring sovereignty to tax. To shed light on the economic constrains on nation states and the beliefs about such constrains, this article introduces the concept of economic-ideological forces and contends that sovereignty should be understood in a way that encompasses these forces. Otherwise, it does not provide an adequate account of power and thus becomes a tool for maintaining established power relations.

Maxillary hollow denture: A literature review

Severely resorbed ridges and increased lip length provides challenge to achieve adequate retention, stability and support for the success of complete denture. In such cases Implant supported dentures can be promising alternative to conventional dentures. However, it is not always possible to provide patients with implant treatment as geriatric patients with systemic illness and economic constrains, possess reluctance for a long duration of treatment procedure and unwillingness for any kind of surgical procedure. Hence the best way is to rehabilitate them in conventional way. Light weight hollow dentures can prove to be an effective alternative to conventional denture for achieving optimum results. The aim of this review is to assess the role of maxillary hollow denture in improving the retention and stability in compromised cases based on the data published in the literature.

Analisis Pengalihan Anggaran Sebagai Solusi Terhadap Hambatan Ekonomi Masyarakat Ponorogo Akibat Covid-19

Ponorogo is one of the many region that is also seriously affected by the COVID-19 outbreak. The purpose of this research aims to analyze related activities made by the Ponorogo government, as an effort to overcome the economic barriers of society due to COVID-19. Based on the reports ang facts in the field, the affected people are those who have not been covered by assistance programs such as PKH or BPNT, around 15.000 people. The method in this research is to find a variety of scientific literature, the latest, and valid form of media coverage, and scientific journals as a reference. Ponorogo government innovates policies by diverting the budget to help the process of the acceleration of handling COVID-19 with the main object is society. The result of this research concluded that the Ponorogo government had succeeded in coordinating and agreeing in the proses of determining the budget diversion policy. The said budget diversion is taken from a number non-priority budgets items, or in other words it can still be delayed. In this researches can be analyzed that of course the budget diversion policy has gone through various considerations ang long-term calculations, so that effort to create economic stability can be carried out as soon as possible. However, what’s need to be underlined is related to how the diversion of budget also creates other impact namely inhibiting development process like infrastructure, housing, settlement, increasing human resources, and so forth. The priority scale determined by the Ponorogo government in passing the crisis period dua to COVID-19 is a manifestation of the principle of good government, that the basic needs of the society are the biggest responsibility (even more so in the era of disasters). In addition, the status of the red zone in Ponorogo itself doses contribute to additional logical reasons for the government to make diversion budget precisely and directed. This research aims to analyze the diversion of budget, as a solution to the economic constrains of Ponorogo society.  Keywords: Analyze, Diversion, Budget, Economic, COVID-19

Reduced phosphorus intake throughout gestation and lactation of sows is mitigated by transcriptional adaptations in kidney and intestine

BackgroundThe environmental impact of pig farming need to be reduced, with phosphorus (P) being of particular interest. Specified dietary regimens and management systems contribute to meet environmental concerns and reduce economic constrains. However, pregnant and lactating sows represent vulnerable individuals, whose reproductive potential and metabolic health status relies on adequate supply of macro- and micronutrients. The aim of this study was to investigate, whether sows fed with a dietary P content that is below or above current recommendations are capable to maintain mineral homeostasis during the reproduction cycle and which endogenous mechanisms are retrieved therefore in kidney and jejunum. Nulliparous gilts were fed iso-energetic diets with recommended (M), reduced (L), or high (H) amounts of mineral P supplements throughout gestation and lactation periods. Blood metabolites and hormones referring to the P homeostasis were retrieved prior to term (110 days of gestation) and at weaning (28 days of lactation). Transcriptional responses in kidney cortex and jejunal mucosa were analyzed using RNA sequencing.ResultsThe variable dietary P content neither led to an aberration on fertility traits such as total weaned piglets nor to an effect on the weight pattern throughout gestation and lactation. Serum parameters revealed a maintained P homeostasis as reflected by unaltered inorganic P and calcium levels in L and H fed groups. The serum calcitriol levels were increased in lactating L sows. The endocrine responses to the dietary challenge were reflected at the transcriptional level. L diets led to an increase in CYP27B1 expression in the kidney compared to the H group and to an altered gene expression associated with lipid metabolism in the kidney and immune response in the jejunum.ConclusionsOur results suggest that current P requirements for gestating and lactating sows are sufficient and over supplementation of mineral P is not required. Shifts in renal and jejunal expression patterns between L and H groups indicate an affected intermediate metabolism, which long-term relevance needs to be further clarified.

A COMPARATIVE STUDY OF IN VIVO EFFECT OF PERCUTANEOUS BONE MARROW INJECTION VS WITHOUT INJECTION ON UNION OF OPEN TIBIAL SHAFT FRACTURES WITH EXTERNAL FIXATOR

Background : Open tibial fractures are notorious fractures because the open wound leaves us with limited options and means multiple operations with long intervals for the patient. The usual method of treatment of contaminated, late presenting and complicated fractures is a temporary external fixator followed by conversion into a costly definitive procedure once the wound has healed. The secondary definitive procedure also means extra cost in an already economically stressed patient.In our set up we have to often let patients leave with a plaster cast after removing the external fixator for economic constrains. Per cetaceous autologous bone marrow injection while the patient is on external fixator is one alternative that we have tried to deal with this problem hoping for a primary union without any costly intervention. Materials and methods : We had 42 cases of open tibial fractures which were treated with external fixator and per cutaneous bone marrow injection while 38 other cases which were used as control with only the external fixator and no injections. We included open fractures of only Gustilo Anderson type II,IIIA and B for our study. Study was conducted between period of June 2012 and December 2013 at SBKS medical college . Results : In group one, 34 of the 42 patients had a radiological union before 12 weeks while another 2 in 16 weeks. For group 2 , only 16 of the 38patients had radiological union at 12 weeks and no more at 16 weeks. The average time of union for group 1 was 10 weeks while of group 2 was 12 weeks .Function of the union cases of both the groups was similar in all aspects including distance of walking and ability to carry out daily activities. Conclusion : Per cutaneous autologous bone marrow injections are cheap , easily available and successful alternative to a secondary procedure for open tibial fractures on external fixators.

A COMPARATIVE STUDY OF IN VIVO EFFECT OF PERCUTANEOUS BONE MARROW INJECTION VS WITHOUT INJECTION ON UNION OF OPEN TIBIAL SHAFT FRACTURES WITH EXTERNAL FIXATOR.

Background : Open tibial fractures are notorious fractures because the open wound leaves us with limited options and means multiple operations with long intervals for the patient. The usual method of treatment of contaminated, late presenting and complicated fractures is a temporary external fixator followed by conversion into a costly definitive procedure once the wound has healed. The secondary definitive procedure also means extra cost in an already economically stressed patient.In our set up we have to often let patients leave with a plaster cast after removing the external fixator for economic constrains. Per cetaceous autologous bone marrow injection while the patient is on external fixator is one alternative that we have tried to deal with this problem hoping for a primary union without any costly intervention. Materials and methods : We had 42 cases of open tibial fractures which were treated with external fixator and per cutaneous bone marrow injection while 38 other cases which were used as control with only the external fixator and no injections. We included open fractures of only Gustilo Anderson type II,IIIA and B for our study. Study was conducted between period of June 2012 and December 2013 at SBKS medical college . Results : In group one, 34 of the 42 patients had a radiological union before 12 weeks while another 2 in 16 weeks. For group 2 , only 16 of the 38patients had radiological union at 12 weeks and no more at 16 weeks. The average time of union for group 1 was 10 weeks while of group 2 was 12 weeks .Function of the union cases of both the groups was similar in all aspects including distance of walking and ability to carry out daily activities. Conclusion : Per cutaneous autologous bone marrow injections are cheap , easily available and successful alternative to a secondary procedure for open tibial fractures on external fixators.

SUBSTANCE ABUSE

Objectives: To study the prevalence of substance abuse among prisoners and itseffects on other inmates. Study design: A cross sectional study. Place and duration of study:Central jail Faisal Abad Pakistan during Jan. 2012 to Feb 2012. Methodology: All the convictedand condemned prisoners were included in the study and those exclusively charged for drugsabuse crimes were excluded. A snow ball convenient sampling technique was adopted. Samplesize was not predetermined. The study population was (1080) male and above the age of 18years. Results: About one hundred and eighty four (184) prisoners were found using differentdrugs. Among them seventy six 76 (41.3%) started using drugs on entering the prison and onehundred and eight 108 (58.7%) were using drugs before coming to prison. The 91(49.5 %)belonged to rural area and 93 (50.5%) belonged to urban areas. The most commonly used drugwas heroin 181(96.7%) and 3(.6%) used different drugs like injections or pills. Conclusions:Substance abuse among prisoners was increasing day by day leading to increased crimes,health issues, and significant economic constrains in every country especially among poornations. Strong political will and public motivation was the need of time to deal with the issue.

A geostatistical protocol to optimize spatial sampling of domestic drinking water supplies in remote environments

This paper deals with the design of optimal spatial sampling of water quality variables in remote regions, where logistics are complicated and the optimization of monitoring networks may be critical to maximize the effectiveness of human and material resources. A methodology that combines the probability of exceeding some particular thresholds with a measurement of the information provided by each pair of experimental points has been introduced. This network optimization concept, where the basic unit of information is not a single spatial location but a pair of spatial locations, is used to emphasize the locations with the greatest information, which are those at the border of the phenomenon (for example contamination or a quality variable exceeding a given threshold), that is, where the variable at one of the locations in the pair is above the threshold value and the other is below the threshold. The methodology is illustrated with a case of optimizing the monitoring network by optimal selection of the subset that best describes the information provided by an exhaustive survey done at a given moment in time but which cannot be repeated systematically due to time or economic constrains.

Indicators of social support in patients with multiple sclerosis in Albania

Multiple sclerosis is a chronic disease that attacks the central nervous system. Objective: The aim of this one year study was to assess the impact of neurological disability in the overall social support domains. Indicators of quality of life are assessed too and social functions and roles, economic constrains, marital status, family relationships and education of patients are included in the study as complementary evidences. Methods: We randomly selected 67 patients diagnosed with multiple sclerosis. Female were 51 (76.1%) and male were 16 (23.9%), mean disease duration was 6 years, (m)education 12 years. In this study social support constrains were measured by MSSS (Modified Social Support Survey) questionnaire (MSQLI scale) which has 4 subscales (I) Tangible Support Subscale (TAN) IIEmotional/Informational Support Subscale (EMI) IIIAffectionate Support Subscale (AFF) IVPositive Social Interaction Subscale (POS). Secondly, MSSS values were divided in 3 categories including: first category MSSS value = 25-45 (21% by total), second category = 45-65 (60%) and third category = 65-85 (19%). Results: In patients with multiple sclerosis we found that mean MSSS subscales values were as follows: TAN 64, EMI47, AFF56, POS48 (range 0-100). Comparison of means showed both EMI and POS had significantly lower MSSS rates; meanwhile Tangible support score indicate greater perceived support. For each of MSSS categories corresponding these levels of disability: First4.4 (3; 8), Second3.1 (2.5; 6) and Third2.6 (2; 5.5) points, assessed by ratings on EDSS (mean). Conclusion: This study show lower MSSS rates and the major constrains was related with the lack of Emotional and Informational support followed by Positive Social Interaction. Harmonised analysis of all MSSS categories showed a direct correlation between reduced social support and overall severity of neurological disability.

Demography, Diagnosis and Complications of Spinal Cord Injury Patients in a Rehabilitation Center of Bangladesh

Background: Spinal cord injury and its health related complications pose a major impact on the overall morbidity and mortality as well as cause economic constrains. It was aimed at looking into the demographic distribution, diagnosis, as well as complications in patients with spinal cord injury. Methods: The study was conducted at Centre for the Rehabilitation of the Paralysed (CRP) between 2012 and 2013 from 201 respondents with the help of a structured preformed pretested questionnaire by face to face interview. Results: Out of 201 respondents 176 (87.6%) were male and 25 (12.4%) were female; majority of the patients were in their 3rd decade which consisted 28.6%, followed by 27.4% in between 21-30 years and 26.8% in between 41-50. Most of the respondents of this study had traumatic paraplegia (56.5%) and Buttock was found to be the predominant site for developing site pressure sore as evident form 67.5%. Conclusion: Productive males are more prone to spinal cord injury and the most common diagnosis is paraplegia with the most risky area is buttock for developing pressure sore. The findings may add in the way of developing awareness among stakeholders regarding demography, diagnosis and the pattern of the complications in a country like Bangladesh.

Miracle drug: Brazil approves never-tested cancer medicine.

Background Brazil recently approved synthetic phosphoetanolamine, a popularly dubbed 'cancer pill', a substance that has been shown to kill cancer cells in lab animal models but was not yet formally accessed in humans, and thus despite the existence of any evidence of its efficacy and safety. Methods The authors describe the recent decision of Brazil to aprove phosphoetanolamine in the context of growing 'judicialization' to promote access to medicines and thus reinforcing a growing sense of legal uncertainty. Results The approval of phosphoetanolamine despite the existence of any evidence of its efficacy and safety represents to the authors one of the saddest and surrealistic episodes in Brazil's recent public health history. Brazil's current economic crisis is fueling the 'judicialization' to promote access to medicines and thus reinforcing a growing sense of legal uncertainty in the context of rising economic constrains and a progressive failing state. The authors state that the Phosphoetanolamine's approval bill violates current legal prohibition of commercialisation of drugs without the Brazilian national drug regulatory agency's approval and thus may represent a potential menace to Brazil's pharmacogovernance and the country's governance to health technology assessment at the Brazilian national health systems. Conclusion Phosphoetanolamine's approval illustrates that the combination of flawed decision making, economic crisis and political interference may threaten weak governance mechanisms for drug regulation and health technology assessment and thus representing an extra burden in the sustainability of universal access-based national health systems.

Numerical Simulation of Heavy Crude Oil Combustion in Porous Combustion Tube

This work presents a compositional numerical model to simulate the combustion of heavy crude oil in a porous combustion tube. The combustion tube experiments replicate an enhanced oil recovery process by in-situ combustion (ISC) of crude oil in a petroleum reservoir. Due to the economic constrains associated with the combustion tube tests, numerical simulation has been identified as an efficient and economical tool in understanding the complex ISC process. In the present model, mass and energy conservations have been drawn considering an advective, diffusive, and reactive flow of multiple components in multi-phase. The model includes temperature- and pressure-dependent fluid properties and considers the effect of capillary pressure. A block-centered finite-difference-based numerical tool with an implicit quasi-Newton iterative solver scheme has been developed to solve the conservation equations. The numerical model is validated with the combustion-tube results reported by Fadaei et al. (2011). The combustion front profile predicted by the present numerical model has been found to be in good agreement with the reported results. The numerical results projected a cumulative oil recovery of about 60% of original oil in place. The combustion front has been found to propagate with an average peak temperature of 715 K.

Chitosan: Emergence as potent candidate for green adhesive market

Chitosan has gained significant attention during last decades as a potent natural adhesive. Its lower concentrations (<10%w/v) offer competitive strength as synthetic adhesives which would reduce economic constrains of adhesive production. There is increasing commercial interest on chitosan as it possesses biodegradability, biocompatibility, non-toxicity and anti-microbial properties which are of high interest for industries and consumers. Moreover, it has reactive amino side groups, which offer possibilities of chemical modification, increased ionic interactions and graft-reactions etc. Degree of deacetylation (DD) and molecular weight (Mw) is important in bonding mechanism. Most of the synthetic adhesives are comprised of petrochemicals that leave toxic residues such as formaldehyde and volatile organic compounds (VOCs), which are injurious to health and environment. Therefore, development of cost-effective, environmental and health-friendly green adhesives, based on renewable resources is main interest of adhesive industries these days. Rising oil prices are another driving force in research for development of bioadhesives as substitute of synthetic adhesives. This review is focused on current developments of chitosan adhesives for structural and general bonding applications during last decades as well as its current market potential worldwide.