The growing reliance on edible oils for biodiesel production raises concerns regarding feedstock availability and cost volatility. Palm stearin (PS), a by-product of palm oil fractionation with reduced demand in food applications, offers an attractive alternative feedstock for biodiesel production. In this study, biodiesel was produced from PS using a continuous deglycerolization reactor (CDR), which removes glycerol during transesterification. The optimal process condition was a methanol-oil molar ratio of 5:1, a potassium methoxide (KOCH3) catalyst loading of 1.2 wt%, a mixing speed of 250 rpm and a glycerol removal rate of 0.25 L h-1. Under these conditions, the CDR produced high-quality biodiesel with an ester content of 97.23 wt% and a yield of 98 wt%. An economic assessment indicated a positive net present value, an internal rate of return above 8% per year, and a payback period of 1.12 years. Sensitivity analysis showed that economic performance is influenced by production cost and biodiesel selling price, with a break-even selling price of US$0.99 L-1. The combination of reduced methanol consumption and the use of lower-cost PS support the economic viability of the proposed process.
Task-based instruction is widely accepted as an effective teaching method, as it helps improve communicative competence via meaningful tasks. This study investigated effects of a task-based oral presentation on reading comprehension of Thai undergraduate English student teachers majoring in English in the Faculty of Education. Participants were 28 second-year students (16 high reading proficiency and 12 low reading proficiency students). They were selected by the convenience sampling method. The instruments were pre-and post-reading comprehension tests. The scores from the two tests were compared after a 10-week task-based oral presentation. The results from the Paired-sample t-test indicated that the oral presentation task significantly improved the students' reading comprehension. An Independent Sample t-test was further employed to compare the pre-and post-test scores between the high-and low-proficiency groups. The results revealed that the high proficiency group significantly outperformed the low reading proficiency group. Additionally, in the pre-reading comprehension test, two significant differences at the 0.01 level were found in reading for topics and reading for details. In contrast, a significant difference at the 0.05 level was found in the meaning in contexts. In the post-test, however, a significant difference at the 0.01 level was found only in reading for details. Implementing a task-based oral presentation in a reading class is suggested to help improve students' reading comprehension, especially among students with low reading proficiency.
Purpose: This study examines the effects of internal readiness, distribution factors, and technology adoption on competitive advantage in small-scale border retail firms. Research design, data and methodology: Data were collected through online questionnaires administered to store owners and managers, with reliability confirmed by Cronbach's alpha values ranging from 0.822 to 0.960. Results: Structural equation modeling with bootstrapping indicates that internal readiness has a strong positive effect on technology adoption (beta = 0.876, p < 0.001). However, internal readiness(beta = 1.527, p = 0.269) and distribution factors (beta = 0.749, p = 0.081) do not have a direct effect on competitive advantage. In addition, distribution factors do not significantly influence technology adoption (beta = 0.135, p = 0.453), and technology adoption alone does not directly enhance competitive advantage (beta = -1.267, p = 0.435). Mediation analysis further reveals that technology adoption does not mediate the effects of internal readiness or distribution factors on competitive advantage. Conclusions: The findings suggest that internal readiness is a key driver of technology adoption, while technology adoption functions primarily as an enabler rather than a direct source of competitive advantage. Distribution factors support the process, but achieving competitiveness requires the strategic integration of internal capabilities.
We investigate the inflationary phenomenology of a marginally deformed Starobinsky model, motivated by quantum corrections to the R2 term, in light of the latest cosmological observations. In this framework, the inflationary potential acquires a small deformation parameter, y, which shifts predictions away from the exact Starobinsky limit. Using the slow-roll formalism, we derive analytic expressions for the spectral index ns and tensor-to-scalar ratio r and confront them with constraints from Planck, ACT, and DESI data. Our analysis shows that nonzero values of y raise both ns and r, thereby alleviating the >= 2 sigma tension between the Starobinsky R2 scenario and the ACT+DESI (P-ACT-LB) measurements, which favor ns similar or equal to 0.9743 +/- 0.0034. For N similar to 60 e-foldings, the model consistently reproduces the observed amplitude of primordial perturbations while predicting tensor contributions within current observational bounds. We also demonstrate that the deformation softens the otherwise severe fine-tuning of the quartic self-coupling in minimally coupled inflation. The parameter range y similar to O(10-3)-O(10-2) emerges as phenomenologically viable, providing a natural extension of Starobinsky inflation compatible with present data. Moreover, the model yields a small running of the spectral index that remains fully consistent with the ACT 95 % confidence constraints. We conclude that marginally deformed R2 inflation remains a compelling and testable candidate for the primordial dynamics of the Universe, with future CMB and gravitational-wave observations expected to further probe its parameter space.
Recent observations from the Atacama Cosmology Telescope (ACT), especially when combined with DESI baryon acoustic oscillation data, indicate a scalar spectral index n_s higher than the value reported by Planck 2018, placing tension on universal inflationary attractor models. Motivated by this discrepancy, we investigate the inflationary predictions of the β -exponential potential, V(ϕ )=V_0( 1-λβϕ /M_p) ^1/β considering both minimally and non-minimally coupled realizations. This potential generalizes standard exponential inflation and naturally arises in braneworld scenarios. We derive analytical expressions for the slow-roll parameters and inflationary observables using a perturbative expansion in the non-minimal coupling ξ , and validate these results through numerical calculations. In the minimally coupled case, the model predicts n_s ≃ 0.976 and r ≃ 0.035 for N=50 and moderate values of β , remaining compatible with ACT+DESI (P-ACT-LB) constraints at the 1σ level while yielding a spectral tilt larger than the universal attractor prediction. Introducing a small non-minimal coupling significantly improves agreement with observations by suppressing the tensor-to-scalar ratio while preserving the enhanced scalar tilt. For N=60 , λ∼ 0.3-0.5 , and β∼𝒪(1-5) , the non-minimally coupled model yields n_s ≃ 0.974-0.976 and r ≲ 0.03 , comfortably consistent with ACT, DESI, and BICEP/Keck bounds. Our results show that the β -exponential potential, especially when implemented with a non-minimal coupling, exhibits good agreement with the latest CMB observations. Our inflationary predictions of the non-minimal model of n_s and r confirming the leading-order contributions in ξ are sufficient to capture the essential features of both r and n_s in observationally relevant regimes.
