Optimization of Scintillator Performance for the Development of Large Scale Scintillation Detector

The Sodium-iodide with Active Background REjection (SABRE) experiment is planned to consist of 50 kg of ultrapure thallium doped sodium iodide (NaI(Tl)) scintillator contained within a liquid scintillation (LS) veto detector of approximately 10,500 kg (2.6 m in diameter and height), and will search for dark matter interactions in the inner NaI(Tl) detectors. Linear alkylbenzene (LAB) has been chosen as the LS solvent for the SABRE South experiment and the LS veto detector design includes numerous materials that will be in contact with the liquid scintillator over the uninterrupted multi-year (3 to 5 years) operation. The SABRE specifications require LAB of high chemical purity and low radioactive background to maximise the light yield and optical attenuation length, thus giving optimum energy resolution and detection efficiency of the LS veto detector. In this study, the service lifetime of Viton O-rings, required as seals in the detector, were examined under different ageing temperatures while exposed to LAB scintillator and to air. Compression set experiments, solvent swelling, Young’s modulus measurements, scanning electron microscopy (SEM) and attenuated total reflection- Fourier transform infrared spectroscopy (ATR-FTIR) all being used. LAB was purified with a custom-made vacuum distillation process to reduce chemical and radioactive impurities. The effects of tentatively identified impurities on the LAB scintillation light yield were investigated with a custom-made scintillation light yield setup. In addition, the optimal LAB LS preparation techniques with higher scintillation light yield were explored. The chemical and physical suitability of selected materials used in detector components (~ 28 types) when in contact with the LAB liquid scintillator (~ 2 types) under normal operation were also investigated based on relative light yield and optical absorbance over the time period of ~ 560 days. In conclusion, the study provides much useful information in regard to LAB purification, scintillation light yield maximization by 13%, optical light attenuation length improvements (~ 4 m), impurity identification and compatibility tests of components with optimization of energy resolution and detection sensitivity for a large-scale veto liquid scintillation detector. This work could aid design and fabrication of other types of scintillation detector for nuclear science, medical and particle physics applications

The Scenario of Buffalo Production and Research in Bangladesh

Background: This study aimed to characterize the scenario of buffalo production in the northern part of Bangladesh and review the published scientific literature on buffalo from Bangladesh. Methods: The study was conducted from August to December 2022. A draft questionnaire was prepared and modified before the final one based on the study's objectives. Data were collected through personal interviews with individual respondents. In addition, the review article was collected on buffalo from Google, Google Scholar, Research Gate, Scopus, Bangladesh Journal-Online (BJO), and PubMed. Results: Data was collected from 1099 animals from the northern part of the Natore and Lalmonirhat districts of Bangladesh. Most of the farmers were illiterate, and the age was above 40 years. Regarding the purpose of buffalo production, 69.16% (n=83) of the farmers narrated that they are motivated to milk with calves selling. The average herd size was about 9 and consisted of indigenous and crossbred buffaloes. Most of the farmers kept their buffalo in the Bathan. The coat color was predominantly black, with brown hair. Farmers 94.16% (n=113) practice de-worming, and the frequency was thrice a year. Wallowing is performed at least once a day in the pond or river for the thermal regulation of the buffalo. Among the farmers, 67.50% (n=81) have no training in rearing buffalo. Farmers practice natural mating by their own or neighbor bull to serve the heated cow. Sometimes it’s free, or sometimes, with payment on an average of BDT 400-500 or 3.79-4.73 US dollars. In some areas, AI is being practiced in buffalo under different organizations (LAL Teer, BRAC), and the cost of AI was recorded as about BDT 600-700 or 5.68-6.63 US dollars per cow. The average daily milk yield was 3.0 liter, whereas the lactation length was recorded at 179.9±3.84 days. The major constraints were high feed price 91.66% (n=110), shortage of land 41.08% (n=51), and lack of suitable marketing facilities 50.82% (n=62). 100% of farmers stated that they need improved grass production technology and reduced feed and medicine price; 24.16% (n=29) need good quality semen. From 2004 to 2022, 51 studies were found related to buffalo, where the highest 27.45% (n=14) belonged to performance studies, and 54.90% (n=28) studies were carried out in the southern part of Bangladesh. Conclusion: It can be concluded that buffalo has great potential with different areas of improvement. Therefore, more research is needed from different perspectives on production, reproduction, nutrition, quality of milk/meat/products, health, and sustainability of buffalo farming in Bangladesh

A Case Study of the Notion and Model of Micro Hydro Power Plant Using the Kinetic Energy of Flowing Water of Burinadi and Meghna River of Bangladesh

Bangladesh is progressing through a stage of development where automation is the solution to its economy. At this stage for the progression of this country electricity is very vital to sustain the economic growth. These days it becomes extremely challenging to cope up with the required energy demand of the country. Continuous increase in price of fuel in the world market and also the unavailability of fuel are the reasons behind this. On the other hand fuel burning in energy generation is responsible for global climate change and Bangladesh residing in high risk of this. Renewable energy can be an immense hope under this circumstance. The country is blessed with a good number of rivers consisting adequate flow of water throughout the year. Harnessing this driving water of rivers can be a great source of kinetic energy and utilizing this kinetic energy of driving water Hydro Electricity can be produced. In this paper the real life practical data of Burinadi and Meghna rivers were considered. A system is introduced that does not need the Dam or Reservoir to produce Electrical Power and is observed that 21.1 MW-hr and 12.48 MW-hr worth of energy can be produced annually from Burinadi & Meghna rivers respectively. This extent of power can be very useful for these rivers nearby inhabitants in remote areas as they are still out of national grid range

Strategic Tillage for Sustaining the Productivity of Broadacre Cropping in the Arid and Semi-Arid Regions of Southern Australia

Conventional tillage, usually practised before every cropping cycle, was proven damaging and unsustainable and was replaced by conservation agriculture (CA) using no-till systems following the ‘dustbowls’ incident in the USA. However, the continuous practice of CA has brought new soil and agronomic challenges, such as soil water repellence, soil pH and nutrient stratification, subsoil acidity, compaction and herbicide resistance, threatening the sustainability of broadacre cropping again. In recent years, one-off deep strategic tillage (ST) has brought attention and shown promise in overcoming the challenges imposed by CA and improving the sustainability of broadacre cropping. Deep ST approaches are now available for applying and incorporating soil amendments such as agricultural lime to a targeted depth while treating soil water repellence and loosening the compacted subsoil. Some ST practices have also been proven to manage weed seed banks and decrease the demand for herbicide applications. Many farmers in southern Australia have adopted ST to address the above-mentioned soil and agronomic challenges. When ST is practised, care should be taken in selecting the right timing, soil conditions and depth of tillage for successful outcomes. Once ST is implemented, reestablishing CA would ensure the longevity of the benefits of ST

Gate Stack Dielectric Degradation of Rare-Earth Oxides Grown on High Mobility Ge Substrates

We report on the dielectric degradation of Rare-Earth Oxides (REOs), when used as interfacial buffer layers together with HfO2 high-k films (REOs/HfO2) on high mobility Ge substrates. Metal-Oxide-Semiconductor (MOS) devices with these stacks,show dissimilar charge trapping phenomena under varying levels of Constant- Voltage-Stress (CVS) conditions, which also influences the measured densities of the interface (Nit) and border (NBT) traps. In the present study we also report on C-Vg hysteresis curves related to Nit and NBT. We also propose a new model based on Maxwell-Wagner instabilities mechanism that explains the dielectric degradations (current decay transient behavior) of the gate stack devices grown on high mobility substrates under CVS bias from low to higher fields, and which is unlike to those used for other MOS devices. Finally, the time dependent degradation of the corresponding devices revealed an initial current decay due to relaxation, followed by charge trapping and generation of stress-induced leakage which eventually lead to hard breakdown after long CVS stressing.Comment: 19pages (double space), 7 figures, original research article, Submitted to JAP (AIP

Does corporate reputation play a mediating role in the association between manufacturing companies' corporate social responsibility (CSR) and financial performance?

The main objective of this research was to analyze the variable of corporate reputation as a mediating variable to determine the relationship between corporate social responsibility and financial performance. Simple random sampling was used in the study to obtain 300 respondents from Bangladeshi manufacturing companies. Statistical Package for the Social Sciences (SPSS) 23.0 was used to analyze the data. To evaluate the hypotheses in this study, structural equation modeling (SEM) was used. The results demonstrated that corporate social responsibility positively influences corporate reputation and financial performance, while corporate reputation is statistically significant for financial performance. Environmental contribution, philanthropic responsibility, legal responsibility, ethical responsibility, economic responsibility and social responsibility are listed in order of significance as corporate social responsibility factors. It was determined how corporate reputation influences the link between corporate social responsibility and financial performance. However, it may be logical to conclude that there is a considerable correlation between corporate social responsibility and financial performance based on the data analysis. The results of corporate social responsibility practices in manufacturing organizations in developing nations, particularly Bangladesh, have significant consequences for businesses, entrepreneurs, communities, researchers and policymakers in understanding the outcomes of sustainability. The conclusion has drawn implications for sustainability practice and future research

Assessing Mechanical Properties of Jute, Kenaf, and Pineapple Leaf Fiber-Reinforced Polypropylene Composites: Experiment and Modelling

The application of natural fibers is increasing rapidly in the polymer-based composites. This study investigates manufacturing and characterization of polypropylene (PP) based composites reinforced with three different natural fibers: jute, kenaf, and pineapple leaf fiber (PALF). In each case, the fiber weight percentages were varied by 30 wt.%, 35 wt.%, and 40 wt.%. Mechanical properties such as tensile, flexural, and impact strengths were determined by following the relevant standards. Fourier transform infrared (FTIR) spectroscopy was employed to identify the chemical interactions between the fiber and the PP matrix material. Tensile strength and Izod impact strength of the composites significantly increased for all the composites with different fiber contents when compared to the pure PP matrix. The tensile moduli of the composites were compared to the values obtained from two theoretical models based on the modified “rule of mixtures” method. Results from the modelling agreed well with the experimental results. Tensile strength (ranging from 43 to 58 MPa), flexural strength (ranging from 53 to 67 MPa), and impact strength (ranging from 25 to 46 kJ/m2) of the composites significantly increased for all the composites with different fiber contents when compared to the pure PP matrix having tensile strength of 36 MPa, flexural strength of 53 Mpa, and impact strength of 22 kJ/m2. Furthermore, an improvement in flexural strength but not highly significant was found for majority of the composites. Overall, PALF-PP displayed better mechanical properties among the composites due to the high tensile strength of PALF. In most of the cases, T98 (degradation temperature at 98% weight loss) of the composite samples was higher (532–544 °C) than that of 100% PP (500 °C) matrix. Fractured surfaces of the composites were observed in a scanning electron microscope (SEM) and analyses were made in terms of fiber matrix interaction. This comparison will help the researcher to select any of the natural fiber for fiber-based reinforced composites according to the requirement of the final product

An Investigation of the Role of Organic Amendments on the Availability of Phosphorus in an Acidic Soil

© 2020 MD. Shahinur RahmanThe recovery of P from organic waste streams (known as organic amendments, OA) is becoming increasingly popular. Besides a source of P, OA have also been reported to increase soil P availability and reduce P adsorption in acidic soil. The main mechanism involves the reduction in the soil P adsorption sites (especially Al and Fe) by the organic anion producing compounds of the OA. Organic anions form organometallic complexes in the soil to reduce P adsorption. The potential representative organic anion producing compounds of the OA are phenolic and carbonyl compounds. The phenolic and carbonyl compounds usually represent the aromatic (such as benzoic, hydroxybenzoic, protocatechuic acids etc) and aliphatic (such as oxalic, malic, citric etc) organic acids, respectively. This study aimed to investigate if these signature phenolics and carbonyl compounds of the OA can be used to predict their role in soil P availability for future prescriptive applications. An acidic soil (Red Chromosol) from the Rutherglen, northeast of Victoria, Australia was collected and waste from two different streams namely food waste and biosolid and their three different processed forms (untreated or raw, biochar and compost) were utilized as sources of OA in this study. Nuclear magnetic resonance (NMR) spectroscopy was utilized to identify forms of C (solid-state 13C NMR) and P compounds (solution-state 31P NMR) in the OA. The effect of OA on soil P availability was studied in a 110-day laboratory incubation study. Further, some selected representative compounds of phenolic and carbonyl C of OA (aromatic and aliphatic organic acids) were tested against soil P availability in another 110-day laboratory incubation experiment. Finally, a plant bioassay experiment with Triticale (genus Triticosecale) was conducted to understand the effect of both OA and organic acid on soil P availability and plant P uptake with or without the addition of external P. Results from incubation of OA with soil showed an increase in soil P availability (Olsen P) and a decrease in soil P buffering capacity, (PBC). An additional increase in soil Olsen P was observed above the total amount of Olsen P from OA that was added. It might imply that this additive increase of the soil Olsen P was due to the substitution of previously fixed P by the action of organic anions (coming from the dissociation of phenolic and carbonyl compounds) and formation of the stable organometallic complexes. This was further supported by a strong and positive correlation between the delta Olsen P (difference between observed and expected Olsen P) and phenolic and carbonyl C content of the OA. The phenolic and carbonyl C content of the OA also showed a significant correlation with the decrease of soil PBC (delta PBC, the difference between treatment and control). In both correlation studies, the ratio of phenolic to carbonyl C compounds of OA showed a strong correlation with soil P availability compared to their total abundance. The contrasting nature of phenolic and carbonyl compounds was speculated as to the reason why there was a high correlation between soil P availability and the ratio of phenolic to carbonyl C content of OA. The OA with a nearly equal abundance of phenolic to carbonyl C content showed a maximum increase in soil P availability. Therefore, it was concluded that the ratio of phenolic and carbonyl C content of OA could be used to predict P availability in acidic soil. In the next study, some naturally occurring aromatic organic acids (representative of the phenolic compounds) and aliphatic organic acids (representative of the carbonyl compounds) were added either individually or in combination (at 1:1 ratio of aliphatic and aromatic organic acids). The experimental results suggested that aliphatic organic acids were more effective in increasing soil P availability and decreasing soil PBC compared to aromatic organic acids. However, the effect of aliphatic organic acids on increasing soil P availability was prolonged when applied in combination with aromatic organic acids at 1:1 ratio. Therefore, this study concluded that the effect of an OA can be predicted based on their phenolic and carbonyl C content. Finally, the results from the plant bioassay experiment showed that the addition of OA increased the soil P availability irrespective of addition of external P to the soil. As hypothesized in the previous study, this increase in soil P availability after OA addition was expected to show a strong correlation with the ratio of phenolic to carbonyl C content of the OA. The correlation study between the soil P availability and the ratio of phenolic to carbonyl C content of the OA showed a moderate to weak correlation. The differences in those studies (laboratory incubation vs pot) were speculated as to the reason for obtaining this moderate to week correlation between the soil P availability and ratio of phenolic to carbonyl C content of the OA. In the plant bioassay experiment, OA and P were added simultaneously to the soil. Therefore, a competition between organic anions (which was coming from dissociation of organic acid compounds of OA) and P and was expected to increase P availability in the soil by reducing P adsorption. However, the preferential sorption of P by Al and Fe compared to organic anions was speculated as the main reason for observed moderate correlation. The phenolic and carbonyl C content of OA would correlate strongly with the soil P availability if OA were added first (which might reduce P sorption by forming organometallic complexes) and then P to the soil as also observed in previous study. Therefore, it was concluded that the phenolic and carbonyl C content of the OA would predict soil P availability better if OA was first added (which would form organometallic complexes) and then P added to the soil rather than adding both simultaneously. The addition of OA significantly increased the plant P uptake and showed a positive correlation with soil Olsen P. There it was concluded that soil Olsen P was a good indicator of plant P availability. In the plant bioassay experiment, organic acid treatments showed no significant effect on soil P availability and plant P uptake compared to the control. This might be due to the addition of organic acids at 10 times lower concentration in this experiment compared to the previous incubation experiment. In conclusion, this thesis showed that the ratio of the phenolic to carbonyl C content of the organic amendments could be used to predict the role of organic amendments on increasing soil P availability. The availability of fertilizer P could also be predicted by phenolic and carbonyl C content, if OA added first and then P added to the soil compared to their simultaneous addition. The OA with a nearly equal abundance of phenolic and carbonyl C content would have a maximum effect on increasing soil P availability. This knowledge would be beneficial for farmers, agricultural landholders and especially OA producers to assess the impact of their organic waste products on soil P availability in the quickest possible time based on the abundance of the signature C compounds (phenolic and carbonyl)

A thorough investigation on hybrid application of biomass gasifier and PV resources to meet energy needs for a northern rural off-grid region of Bangladesh: A potential solution to replicate in rural off-grid areas or not?

Rural electrification is a critical global challenge specifically in developing countries and Bangladesh is no exception. Most of the people live in the rural areas of the country and having no access to grid electricity hindering the development of these areas and the overall progress of the country's economy severely. In this regard, renewable energy based hybrid mini-grid can be a viable solution to ensure access to electricity for all. This paper presents a case study of supplying electricity through hybrid mini-grid to the rural unelectrified areas of the northern region of Bangladesh, and provides an analysis of its business creation, operation and related challenges. The study involves modelling of three alternative configurations for electricity generation with the different combination of solar energy, biomass generator, diesel generator and battery storage resources. Hybrid Optimization Model for Electric Renewable (HOMER) software is used to carry out the techno-economic analysis and identify the optimal off-grid system configuration. The analysis exposed that the per unit cost of electricity from the optimum off-grid supply configuration is much higher than the regulated tariff for grid connected residential consumers and cannot reach grid parity even with the full capital subsidy. However, the cost of off-grid supply is economical than the diesel-only supply option or the cost of owning a solar home system. The analysis further considered different electricity selling tariff to obtain a practical and reasonable payback period to make the proposed hybrid mini-grid system economically worthwhile. From the emission analysis, it is found that the proposed hybrid system would produce 75% lower CO2 than the existing methods of fulfilling energy needs in the study area