Recycling Waste Glass to Develop Low-CO2 Foamed Composites: Advancing Sustainability

Over 750,000 vehicles in Australia reach the end of their lifespan yearly, leading to the disposal of 22,500 tonnes of waste glass (WG) from their windshields and windows. These materials are usually sent to landfills due to their complex structure and costly recycling process. However, this thesis proposes an alternative by utilising WG as the primary raw material for producing sustainable Low-CO2 foamed composites (FC). The FCs, particularly glass foam and alkali-activated foamed composites (AFCs) are increasingly used in insulation, water treatment, and energy sectors, replacing conventional materials that are flammable, energy-intensive, and expensive. Since glass foam manufacturing is energy-intensive and non-eco-friendly due to its involvement with different chemicals and high-temperature melting-annealing (1400℃), researchers tried to develop alternative methods such as powder sintering and gel casting. These methods enable the sintering of glass foam mixtures at lower temperatures (700-1000℃), aiming to reduce energy consumption, reduce emissions from materials and create a sustainable manufacturing process. Uniformly distributed, finely sized, and homogeneous pores play a crucial role in the properties and application of FC. However, the powder sintering method, which relies on stabilising chemicals to enhance pore characteristics, emits CO2; and faces limitations in industrial applicability due to the need for pelletisation of dry glass powder for achieving uniform particle contact. On the other hand, gel-casting is recognised as an eco-friendly method but requires a lengthy gelation process at elevated temperatures, which is energy-inefficient. Additionally, the controlling parameters that influence foaming, reactivity, and fresh properties of the mix, and their correlation with pore formation and distribution in the final FCs, are not well understood. Hence, this thesis aims to develop sustainable and eco-friendly methods to enhance the pore characteristics of glass foam and AFCs, addressing these challenges and knowledge gaps. The main objectives include comprehensive investigations into the parameters controlling activation, foaming, and fresh and final properties of glass foam and AFCs, fostering a thorough understanding and bridging existing knowledge gaps. In this thesis, a curing-sintering method is proposed to eliminate the use of a chemical stabilising agent and the associated emissions from the materials during sintering. The method involves a process wherein glass powder, fly ash additive, and calcium carbonate foaming agent were mixed with water and cured in sealed plastic wraps. After the curing process, the samples were sintered at 800℃. During curing, physical interlocking, filler effects of the particles and the alkalinity of the glass and calcium carbonate aid in forming weak bonds along the particle surfaces. These weak bonds ensure uniform contact and stability among the particles, eliminating the need for pelletisation. Moreover, this stabilisation process helps maintain pore stability during sintering and achieve homogenous pore size distribution. Additionally, it contributed to reducing the leaching of metals from the glass foam. It is noteworthy that during sintering, regardless of the energy source perspective, the decomposition of calcium carbonate resulted in CO2 emissions detected in the gas analysis test. This thesis presents a novel combined mechanical and chemical foaming technique to completely eliminate emissions from materials during foaming, reduce energy consumption during gelation, and enhance pore characteristics in glass foams. The process involves rapid alkali-activation of precursors, followed by controlled foaming and subsequent hardening. The resulting glass foams were then sintered at temperatures ranging from 700°C to 800°C. The low-speed mechanical foaming applies minimal shearing stress to the activated paste, while surfactants reduce surface tension, preventing pore coalescence. Additionally, chemical foaming using low-concentration hydrogen peroxide minimises anisotropic pore formation. As a result, the desired pore distribution was achieved without the need for lengthy gelation. The correlation between controlling parameters, reactivity in the mix, foaming, and their impact on the final properties of FC was investigated through chemical, rheological, microstructural, and mechanical characterisations at different stages of the process. The activated mix underwent percolation and partial dissolution of precursor particles. During the hardening process, inter-particle gel interactions, cross-linking of the gels, and rigidification of the network occur sequentially and concurrently with foaming caused by hydrogen peroxide decomposition. The formation and cross-linking of the gels contribute to the structural build-up of the system, ensuring pore stability in fresh FC. By promoting the early-age reactivity of the precursor mix, the pore structure in these foams can be controlled. Key parameters for controlling reactivity include water-to-binder ratio, rapid-setting binder (slag), activator, and curing conditions. Through optimised mix design and controlled parameters in the combined foaming method, sustainable AFCs can be developed at ambient conditions using a high volume of WG as the primary raw material, without requiring sintering. It is anticipated that the findings of this research will contribute to a comprehensive understanding of the control of process parameters and pore structure in glass foam and alkali-activated foamed materials using sustainable and environmentally friendly approaches. Ultimately, this study presents a commercially viable and more eco-friendly method for recycling waste glasses from vehicle windows and windshields, transforming them into low-CO2 foamed composites for use in various industries

Craniofacial morphometry in Saudi population

The purpose of this research is to have a better understanding of the craniofacial morphometric structures and comparison of the sexual dimorphism of the Saudi population. The ethnicity, hard tissue,soft tissue and dental features should be considered during treatment, especially in orthodontics and orthognathic surgery. Lateral cephalometric radiograph for cephalometric analysis provides details about skeletal structure relationships, relationships between skeletal structures with the teeth and facial soft tissue structures. The lateral cephalometric radiographs help the orthodontists to pay attention to the current facial structures as well as predict future facial growth when planning a treatment plan for the patient. It is a cross sectional study of 500 lateral cephalometric radioghraphs which contain 250 males and 250 females. These samples were recruited from the Dental Center, King Khalid General Hospital, Hafer al Batin, Kingdom of Saudi Arabia with age group 18 to 30 years old. All the radiographs were traced by using CASSOS software. All the radiographs were analyzed by using Burstone, Down, Eastman, Holdaway, Jarabak, McNamara, Ricketts, Steiner, Tweed, Wits analysis. In this study there were some statistically differences in some of the measurements as compared to other established morphometric data, therefore Saudi population requires its own cephalometric analysis as a reference. Multi cephalometric analysis are essential for providing complete craniofacial morphometric information whereby it‘s included hard tissue, soft tissue and dental structures of its own racial group

Cephalometric for Orthognathic Surgery (COGS) Analysis for Saudi Population

Objective: To establish the cephalometric (Ceph.) norm by Ceph. for orthognathic surgery (COGS) analysis for Saudi population. Material and Methods: 500 adult Saudi samples (250 males and 250 females) with the age range of 18-30 years old were selected for this study. The selections of samples were based on a normal occlusal relationship, no history of facial trauma and no previous orthodontic treatment. Lateral Ceph. radiographs were tracing by CASSOS software and analyzed by SPSS software according to COGS analysis. Results: Significant differences were showed between the Saudi males and females on most of the Ceph. parameters. The Saudi males had a convex facial profile with chin prominent and more bimaxillary protrusion, upper and lower lip protrusion than the Saudi females. Conclusion: This study evaluated the craniofacial morphological difference between the male and the female population in Saudi Arabia by using COGS analysis. The finding of this study will help for better diagnosis of orthodontic and orthognathic surgical treatment planning and identify the morphological facial characteristics of Saudi patients

Ricketts’ Cephalometric Analysis for Saudi Population

Objective: To evaluate the cephalometric norm for Saudi sample by Ricketts analysis (RA). Material and Methods: In this cross-sectional study, cephalometric radiographs were taken for 500  samples. The subjects included 250 males and 250 females. The ages of the subjects ranged from 18-30years. The criteria of selection were based on Class I incisor relationship, no skeletal abnormality and no previous orthodontic treatment. Lateral cephalometric radiographs were taken, traced and digitized by SPSS software, according to RA. An independent t-test was used to test the level of significance between genders.  Results: Significant disparities found between Saudi males and females in dental and soft tissue measurements. The result showed that the distal position of the maxillary first molar to pterygoid vertical plane (U6 to Ptv) measurement was highly significantly greater (p<0.001) in Saudi males than females. Lower incisor to A- Pog (L1 to A-Pog) and lower lip to E plane was significantly longer (p<0.05) in Saudi males than females. Other measurements had no significant difference between Saudi males and females. Conclusion: The craniofacial morphology of the Saudi males was different from Saudi females using Ricketts analysis. This study will help the clinicians to diagnosis and treatment planning of orthodontic and orthognathic patients

Cryopreservation of quince (Cydonia oblonga mill.)

BACKGROUND: Quince (Cydonia oblonga Mill.) has great potential for utilisation in pharmaceutical and food industries. OBJECTIVE: The study was to develop an efficient cryopreservation approachfor quince. METHODS: Factors on the survival and regrowth such as cold acclimation, explant type and recovery media composition were assessed. The effectiveness of the resultant protocols for a number of quince cultivars was determined. RESULTS and CONCLUSION: Quince shoot tips and nodal sections are successfully cryopreserved. Sustained regrowth of quince ‘Angers A’ was observed after encapsulation-osmoprotection/dehydration, encapsulation-dehydration and PVS2 vitrification. The highest regrowth rate (80%) was obtained from explants excised from cold hardened shoots and cryopreserved using encapsulation-osmoprotection/dehydration and vitrification protocols. The optimised vitrification protocol in combination with shoot cold hardening and a MS recovery mediumwithout activated charcoal and auxin resulted in satisfactory regrowth of shoots from six quince cultivars. The morphology of acclimatised plants derived from cryopreserved shoots was comparablewith non-cryopreserved plants.Ayesha Siddika is grateful to the University of Derby for the research studentship. The authors acknowledge the Commission of European Union for funding 196 support through CRYMCEPT (Establishing Cryopreservation Methods for Conserving European Plant Germplasm Collections, Quality of Life and Management of Living Resources, QLK5-CT-2002-01279) and CRYOPLANET, COST Action 871 (Establishing Cryopreservation of Crop Species in Europe ). Maurizio Lambardi thanks the Ente Cassa di Risparmio of Florence for the support for this study (project POLICENTRO)

Effectiveness of combined use of misoprostol with intracervical catheter for induction of labour: a randomized control trial

Background: Labor induction methods are continuously evolving to ensure safer and more effective outcomes for both mother and neonate. The present study aimed to assess the effectiveness and safety of combined use of misoprostol with intracervical catheter for labor induction. Methods: This single-blinded, parallel-group randomized control trial conducted at Shaheed Suhrawardy Medical College, Dhaka, Bangladesh, included 200 women with term gestation and Bishop score ≤6. Participants were divided into two groups: the intervention group (group B) received misoprostol juice and Foley’s catheter, while the control group (group A) received misoprostol in the posterior fornix. Results: In Group A, 58% had vaginal deliveries, while in Group B, 65% had vaginal deliveries. Group B experienced a longer mean length of labor in the 1st stage (13.25±1.095) compared to Group A (12.98±1.982, p=0.008). The 3rd stage was shorter for Group B (10.00±0.000) than Group A (12.02±2.469, p<0.001). The most common induction reason was labor pain with an unfavorable cervix (31 in Group A and 33 in Group B). Group B had a higher percentage of inductions at less than 12 hours and a lower percentage at more than 24 hours. Neonatal outcomes were generally better for Group B. The Cox regression hazard model showed a lower likelihood of positive outcomes in Group B (hazard ratio 0.337, 95% CI 0.243-0.469, p=0.000), indicating a statistically significant difference between the groups. Conclusions: The combined use of misoprostol with Foley’s catheter for labor induction is safe and effective, resulting in shorter labor duration and higher rates of vaginal delivery compared to misoprostol alone

Performances, challenges and opportunities in strengthening reinforced concrete structures by using FRPs – A state-of-the-art review

Structures are often subjected to extreme loading conditions that lead to their premature deterioration, and replacement of those structures before the end of their design lives is very expensive. The rehabilitation of deteriorated structures by using externally bonded fibre-reinforced polymer (FRP) composites is gaining popularity in the construction sector owing to its high strength, optimum durability and compatibility with concrete structures during application. This paper aims to review the current state-of-the-art on the performances, challenges and future opportunities of FRP-strengthened reinforced concrete (RC) structures under different loading scenarios. FRP strengthening leads to satisfactory performances under static, dynamic and extreme environmental conditions. Debonding and FRP rupture are the common types of failure observed, however, the failure mechanisms operating under the combined action of service loads and environmental exposures are still unclear. The acceptance and application of FRPs in strengthening RC structures will further increase upon developing techniques for utilising the full FRP strength, reducing the brittleness, risk of fires and accidental damage, minimising the energy consumption as well as carbon emission during production, and reducing the high initial cost. This paper also identifies the gaps in the present state of knowledge and the potential research directions for FRP-strengthened structures that lead to better understanding and establishment of design guidelines

Phenotypic and genotypic screening of rice genotypes at seedling stage for salt tolerance | Selección fenotípica y genotípica de genotipos de arroz para tolerancia a la salinidad en la etapa de plántulas

Selection for salinity tolerant genotypes of rice based on phenotypic performance alone is less reliable and will delay in progress in breeding. Recent advent of molecular markers, microsatellites or simple sequence repeats (SSRs), have been useful in finding salt tolerant rice genotypes. Three selected SSR markers already known to be polymorphic, viz., 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. Phenotyping was done in hydroponic system using salinized (EC 12 dS/m) nutrient solution following IRRI standard protocol. Large variation in salinity tolerance among the rice germplasms was detected. Salt stress (EC 12 dS/m) reduced seedling height by 19.0% and total dry matter of tolerant lines by 40.6%, whereas, total dry matter of susceptible lines were reduced by 46.0-73.5%. All the tested markers were polymorphic and were able to discriminate salt tolerant genotypes from susceptible. The genotypes having similar banding pattern with Pokkali were considered as salt tolerant. Markers RM7075, RM336 and RM253 identified eight, nine and seven salt tolerant genotypes, respectively. Through phenotypic and genotypic study, three genotypes viz., Pokkali, TNDB-100 and THDB were identified as salt tolerant rice genotypes. These SSR markers might have sequence homology with salt tolerant rice genotypes and consequently the markers could able to identify salt tolerant rice genotypes from susceptible ones. Key words: rice, salinity tolerance, SSR markers, seedling stage. RESUMEN La selección para resistencia a la salinidad de genotipos de arroz, basada solamente en el comportamiento fenotípico, es menos confiable y retarda el avance en el mejoramiento. Se han utilizado avances recientes en marcadores moleculares, microsatélites o repeticiones de secuencias simples (SSR por sus siglas en inglés) para determinar genotipos de arroz tolerantes a la salinidad. Se utilizaron tres marcadores SSR viz., RM7075, RM336 y RM253 para evaluar genotipos de arroz para tolerancia a la salinidad. La evaluación fenotípica y genotípica para la tolerancia a la salinidad se realizó en la etapa de plántula. La fenotipificación de once genotipos se realizó en un sistema hidropónico utilizando solución nutritiva salinizada (CE 12 dS/m). Se siguió el protocolo estandarizado del IRRI para evaluar la tolerancia a la salinidad. Se detectó una gran variación en la tolerancia a la salinidad entre el germoplasma de arroz. La altura de las plántulas y la materia seca total de las líneas tolerantes se redujeron en un 19,0 y 40,6%, respectivamente, bajo estrés salino (CE 12 dS/m), en tanto que las de las líneas susceptibles se redujeron en un 46,0% y 73,5%, respectivamente. Los marcadores mostraron polimorfismo y fueron capaces de discriminar los genotipos tolerantes a la salinidad de aquellos susceptibles. Los genotipos con un patrón similar de bandas a Pokkali se consideraron como tolerantes a la salinidad. Los marcadores SSR (RM7075, RM336 y RM253) identificaron ocho, nueve y siete genotipos tolerantes a la salinidad, respectivamente. A través del estudio fenotípico y genotípico, tres genotipos viz., Pokkali, TNDB-100 y THDB se identificaron como cultivares de arroz tolerantes a la salinidad. Estos marcadores SSR podrían tener homología de secuencias con genotipos de arroz tolerantes a la salinidad y por consiguiente, los marcadores podrían ser capaces de identificar genotipos de arroz tolerantes a la salinidad de aquellos susceptibles. Palabras clave: Arroz, tolerancia a la salinidad, marcadores SSR, etapa de plántulas

THE SCENARIOS OF COVID-19 PANDEMIC IN BANGLADESH: ANALYSIS OF DATA IN JULY ANDAUGUST’2020

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic quickly surges throughout the world including Bangladesh from the beginning of 2020. To challenge the present detrimental situations, many countries are approving several preventive measures, e.g., international travel bans, isolated office activities, country lockdown, and most importantly social distancing, even though some medications are prescribed in some extent. The government of Bangladesh also took various preventive measures to limit the thunder of corona virus disease 20019 (COVID-19) pandemic. But, the actions are not adequate to face the challenges of COVID-19 in Bangladesh, particularly in the capital city Dhaka, remarkably because of the lower-middle-income economy with one of the world’s densest populations. In Dhaka city, based on the present populations, social distancing is difficult, and with the nominal resources it would be extremely challenging to implement the mitigation measures of COVID-19. Mobile sanitization facilities, temporary quarantine sites and healthcare facilities could help to improve the pandemic effect. A rapid, caring, and empathic collaboration between the government, citizens, and health experts, along with international assistance, can enable the country to minimize the impact of the pandemic. In this review, we summarize the occurrence (RT-PCR based test) and present scenarios of COVID-19 outbreak in Bangladesh, particularly in the Dhaka city analyzing available data in July and August’2020