Alkali-activated foam: Understanding the relationship between rheology, activator-precursor interaction, and pore characteristics

The pore characteristics and stability of alkali-activated foams (AAFs) are crucial factors that determine their application and performance. These aspects are influenced by the material mix design and the foaming method employed. The interaction between the activator and precursor paste results in a change in the rheological properties which possess significant impacts on the behaviour of the foam and the stability of the pores in AAFs. Various raw materials and foaming methods have been utilised to develop AAFs. However, The combined influence of the activator-precursor interaction, foaming, and rheological properties on the pore structure and properties of AAFs is not well explored. Hence, the purpose of this study is to investigate this interrelationship. To develop AAFs, a combined mechanical and chemical foaming method was employed. Waste glass, fly ash, and slag were used as precursors and activated using activators with varying silica modulus. The rheological parameters of the paste and the hardened properties of the AAFs were investigated. The findings indicate that pastes with high viscosity and high yield stress have more stable and uniformly distributed pores. The presence of a viscous activator reduces the colloidal interaction between precursor particles, thereby lowering the yield stress of the activated paste. Furthermore, the early setting of slag and the partial dissolution of all precursors play a significant role in establishing stable networks and final pore stabilisation within the AAFs. Controlling these parameters, lightweight AAFs were developed using a high volume of waste glass with homogeneous pore distribution and moderate mechanical strength (up to 2.83 MPa)

Implications of the Rohingya Relocation from Cox’s Bazar to Bhasan Char, Bangladesh

This IMR Dispatch attempts to elucidate the different concerns of human right groups and international communities over the relocation of the Rohingyas, a forcefully displaced ethnic minority of Myanmar, from the Cox's Bazar refugee camps, in mainland Bangladesh, to a newly developed island, Bhasan Char, in the Bay of Bengal. Of the nearly 1 million Rohingyas currently living in Cox's Bazar camps, the Bangladesh government has started relocating 100,000 Rohingyas to Bhasan Char. International organizations have expressed three concerns over this relocation strategy: first, that the Rohingyas have been relocated to Bhasan Char forcibly, second, that since Bhasan Char is a newly built island, there are potential environmental risks for the Rohingyas, and third, that this relocation does not ensure that the Rohingyas’ human rights will be respected on the island. The Bangladesh government, however, has dismissed these allegations, arguing that the relocation of 100,000 Rohingyas is voluntary and that the island provides them an opportunity for improved living. This IMR Dispatch reflects on those allegations concerning the relocation strategy, with the goal of drawing migration scholars’ attention to these developments. Since the Rohingyas are already a forcibly displaced community, migration scholars should pay close attention to this re-migration or onward migration of large numbers of Rohingyas to a new island and its implications for host-country approaches to forced migration

Phenotypic and genotypic screening of rice genotypes at seedling stage for salt tolerance

Selection for salinity tolerance genotypes of rice based on phenotypic performance alone is less reliable and will delay progress in breeding. Recent advent of molecular markers, microsatellites or simple sequence repeats (SSRs) are used to find out salt tolerant rice genotypes. Three selected SSR markers; RM7075, RM336 and RM253 were used to evaluate rice genotypes for salt tolerance. Phenotypic and genotypic evaluation for salinity tolerance was done at the seedling stage. Phenotypingof 11 genotypes was done in hydroponic system using salinized (EC 12 dS/m) nutrient solution. IRRI standard protocol was followed to evaluate salinity tolerance. Large variation in salinity tolerance among the rice germplasms was detected. Plant height and total dry matter of tolerant lines were reduced by 19.0 and 40.6%, respectively under salt stress (EC 12 dS/m), whereas those of susceptible lines were reduced by 46.0 and 73.5%, respectively. The markers showed polymorphism and were ableto discriminate salt tolerant genotypes from susceptible. The genotypes having similar banding pattern with Pokkali were considered as salt tolerant. The SSR markers (RM7075, RM336 and RM253) identified8, 9 and 7 salt tolerant genotypes, respectively. Through phenotypic and genotypic study, three genotypes viz., Pokkali, TNDB-100 and THDB were identified as salt tolerant rice cultivar. These SSR markers might have sequence homology with salt tolerant rice genotypes and consequently themarkers could able to identify salt tolerant rice genotypes from susceptibles

An experimental study to compare the interface pressure and experience of healthy participants when lying still for 20 minutes in a supine position on two different imaging surfaces

Introduction: Pressure ulcers are a high cost, high volume issue for health and medical care providers, affecting patients’ recovery and psychological wellbeing. The current research of support surfaces on pressure as a risk factor in the development of pressure ulcers is not relevant to the specialised, controlled environment of the radiological setting. Method: 38 healthy participants aged 19-51 were placed supine on two different imaging surfaces. The XSENSOR pressure mapping system was used to measure the interface pressure. Data was acquired over a time of 20 minutes preceded by 6 minutes settling time to reduce measurement error. Qualitative information regarding participants’ opinion on pain and comfort was recorded using a questionnaire. Data analysis was performed using SPSS 22. Results: Data was collected from 30 participants aged 19 to 51 (mean 25.77, SD 7.72), BMI from 18.7 to 33.6 (mean 24.12, SD 3.29), for two surfaces, following eight participant exclusions due to technical faults. Total average pressure, average pressure for jeopardy areas (head, sacrum & heels) and peak pressure for jeopardy areas were calculated as interface pressure in mmHg. Qualitative data showed that a significant difference in experiences of comfort and pain was found in the jeopardy areas (P<0.05) between the two surfaces. Conclusion: A significant difference is seen in average pressure between the two surfaces. Pain and comfort data also show a significant difference between the surfaces, both findings support the proposal for further investigation into the effects of radiological surfaces as a risk factor for the formation of pressure ulcers

The effects of clinical support surfaces on pressure as a risk factor in the development of pressure ulcers, from a radiographical perspective: a narrative literature review

Purpose: Pressure ulcers are a high cost, high volume issue for health and medical care providers, having a detrimental effect on patients and relatives. Pressure ulcer prevention is widely covered in the literature, but little has been published regarding the risk to patients in the radiographical setting. This review of the current literature is to identify findings relevant to radiographical context. Methods: Literature searching was performed using Science Direct and Medline databases. The search was limited to articles published in the last ten years to remain current and excluded studies containing participants less than 17 years of age. In total 14 studies were acquired; three were excluded as they were not relevant. The remaining 11 studies were compared and reviewed. Discussion: Eight of the studies used ‘healthy’ participants and three used symptomatic participants. Nine studies explored interface pressure with a range of pressure mat technologies, two studies measured shear (MRI finite element modelling, and a non-invasive instrument), and one looked at blood flow and haemoglobin oxygenation. A range of surfaces were considered from trauma, nursing and surgical backgrounds for their ability to reduce pressure including standard mattresses, high specification mattresses, rigid and soft layer spine boards, various overlays (gel, air filled, foam). Conclusion: The current literature is not appropriate for the radiographic patient and cannot be extrapolated to a radiologic context. Sufficient evidence is presented in this review to support the need for further work specific to radiography in order to minimise the development of PU in at risk patients

Predictors of Locoregional Recurrence in Oral Squamous Cell Carcinoma

Introduction: Lip and oral cavity cancer is the third and fifth most frequent cancer for men & women respectively in Bangladesh. Locoregional recurrence after primary surgery is common for oral cancer due to aggressive local invasion and metastasis. The objective of this study was to analyze the predictors of locoregional failure in a tertiary center hospital. Materials and Methods: A prospective cohort study was designed to analyze the presence of recurrences of OSCC patients after surgery. The purposive sampling technique was used to include patients in the study. Excision of the primary tumor was done with neck dissection followed by reconstruction with local or regional flap. The variables considered were demographic information, site, TNM stage at diagnosis, margin status, lymph node metastasis, perineural invasion, recurrence, and the adjuvant therapy used for disease control. Patients were followed up by hospital revisits or phone calls and necessary information was collected through a standardized data collection sheet. Results: A total of 39 patients were included for data analysis. The male to female ratio was 1:2 and the most common primary site was mandibular alveolar mucosa (31%). Nearly 90% of patients were admitted with stage ׀׀׀ or ׀ᴠ lesions and tumor margin was positive in 21% of cases. Lymph node metastasis and perineural invasion were identified in 64% and 23% of cases respectively. Recurrence developed in 14 patients (36%) during the average follow-up of 13 months. Recurrences were more common in females (42%) and Postoperative histopathology showed a positive margin, perineural invasion, and N3 neck node. Univariate logistic regression analysis for locoregional recurrence showed no significant association between the variables and recurrence. Patients with clinically palpable lymph node, grade 2 lesion, presence of perineural invasion, presence of co-morbidity, patients who did not receive any adjuvant therapy, and patients who had metastatic neck node showed an increased odds ratio (OR>1). Conclusion: The clinicopathologic and treatment-related factors of recurrence in OSCC were explored in this study. Although no significant association was identified between the variables and recurrence of lesions, a high recurrence rate was observed in a shorter span of the follow-up period